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Endodontic irrigation protocols are not only used to clean and disinfect the root canal system, but also to condition the canal wall dentine for subsequent root filling. In this study we tested whether a final irrigation step with saline solution or 80% ethanol improved root canal sealabilty by two popular sealers, an epoxy resin (AH Plus) and a hydraulic calcium silicate cement-based product (BioRoot RCS). Root canals in extracted single-rooted human teeth were instrumented and filled with a matched gutta-percha cone and sealer. During instrumentation and prior to root filling, sealer-specific irrigation protocols were applied. These involved a combined sodium hypochlorite/1-hydroxyethylidene-1,1-diphosphonic acid application, which was followed by irrigation with ethylenediaminetetraacetic acid (EDTA) for AH Plus. Protocols were followed by a 5-ml ultimate rinse with saline solution or 80% ethanol. No such final rinse was the control (N = 9). Canals were then dried with matched paper points. One week after root filling and storage of the teeth at 37°C in a humid environment, Rhodamine B was used to trace leakage. Two-way ANOVA revealed that the type of sealer had a significant (P < 0.05) impact on apical dye penetration while the final rinse did not (P > 0.05). AH Plus provided the slightly better seal (P < 0.05). Leakage occurred between the sealer and the dentin with AH Plus, and between the sealer-to-dentin as well as the sealer-to-gutta-percha interface with BioRoot RCS. In summary and under current conditions, there was no benefit from applying saline or ethanol as an ultimate rinsing solution prior to drying the canal with matched paper points., (Copyright 2024 Nidambur Vasudev Ballal, Rajkumar Narkedamalli, Josette Camilleri, Vasileios Kapralos, Matthias Zehnder. License: This work is licensed under a Creative Commons Attribution 4.0 International License.)

Objectives: The low durability of composite resin restorations can be attributed to the degradation of the resin dentin bonding interface. Owing to the presence of hydrophilic components in the adhesive, the integrity of the resin dentin bonding interface is easily compromised, which, in turn, leads to a reduction in bond strength. The hydrophilic nature of the adhesive leads to water sorption, phase separation, and leaching of the resin component. Therefore, hydrophobic adhesives could effectively be used to stabilize the integrity and durability of the resin dentin bonding interface., Methods: We synthesized a novel hydrophobic dentin adhesive by partially replacing bisphenol A glycidyl dimethacrylate (Bis-GMA) with a light-curable urushiol monomer. The properties of the produced adhesive, including the degree of conversion, viscosity, contact angle, water sorption/solubility, and mechanical strength, were comprehensively examined and compared to those of the commercially adhesive Adper Single Bond 2 as a positive control. The adhesive properties were determined using microtensile bond strength measurements, laser confocal microscopy, scanning electron microscopy observations, and nanoleakage tests. Finally, the novel adhesive was subjected to biocompatibility testing to determine its potential cytotoxicity., Results: At a light-curable urushiol content of 20 %, the synthesized adhesive exhibited high degrees of conversion and hydrophobicity, low cytotoxicity, good mechanical properties, and outstanding adhesive strength., Conclusions: The introduction of the light-curable urushiol into dentin adhesives can significantly enhance their hydrophobic, mechanical, and bonding properties, demonstrating potential to significantly improve restoration longevity., Clinical Significance: The integration of light-curable urushiol has endowed the experimental adhesives with several enhanced functionalities. These notable benefits underscore the suitability of this monomer for expanded applications in clinical practice., Competing Interests: Declaration of competing interest This manuscript has not been published or presented elsewhere in part or in entirety and is not under consideration by another journal. All study participants provided informed consent, and the study design was approved by the appropriate ethics review board. We have read and understood your journal's policies, and we believe that neither the manuscript nor the study violates any of these. There are no conflicts of interest to declare., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction and Aims: The gaps at the margins of restorative composite resin can increase as the carious process occurs underneath the materials, causing further demineralization along the tooth cavity wall. The aim of this study was to evaluate the effects of restorative resin composite containing hydrated calcium silicate (hCS) filler on enamel protection against demineralization by simulating microleakage between the test material and teeth in a cariogenic environment., Methods: The experimental resin composites were composed of 70 wt.% filler, which was mixed with a glass filler and hCS in a weight ratio of 70.0% glass (hCS 0), 17.5% hCS + 52.5% glass (hCS 17.5), 35.0% hCS + 35.0% glass (hCS 35.0), and 52.5% hCS + 17.5% glass (hCS 52.5). A light-cured experimental resin composite disk was positioned over a polished bovine enamel disk, separated by a 30-µm gap, and immersed in artificial saliva with pH 4.0 for 15, 30, and 60 days. After the immersion period, the enamel disk was separated from the resin composite disk and evaluated using a microhardness tester, atomic force microscopy, and polarized light microscopy. The opposing sides of the enamel and resin composite disks were observed using scanning electron microscopy/energy dispersive X-ray spectrometry., Results: The enamel surface showed a significant increase in microhardness, decreased roughness, and remineralization layer as the proportion of hCS increased (P < .05). In the scanning electron microscopy image, the enamel surface with hCS 35.0 and 52.5 after all experimental immersion periods, showed a pattern similar to that of a sound tooth., Conclusions: The results demonstrated that increasing the hCS filler level of restorative resin composites significantly decreased enamel demineralization., Clinical Relevance: Hydrated calcium silicate laced restorative resin composites may be a promising dental biomaterial for protecting teeth against demineralization and preventing secondary caries around restorations., Competing Interests: Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to investigate the microleakage of atraumatic glass ionomer restorations with and without silver diammine fluoride (SDF) application. Restorations with SDF are termed silver-modified atraumatic restorations (SMART). Methods: Sixty carious extracted permanent teeth were randomly allocated to two SMART groups and two control groups (n equals 15 per group) for a total of four groups. After selective caries removal, test specimens were treated with 38 percent SDF and polyacrylic acid conditioner was applied and rinsed; teeth were restored with Fuji IX GP® glass ionomer (n equals 15) or with SMART Advantage™ glass ionomer (SAGI; n equals 15). For control groups, specimens were restored with their respective GI material after selective caries removal, both without SDF. Restored teeth were placed in Dulbecco's Phosphate-Buffered Saline solution at 37 degrees Celsius for 24 hours. Teeth were thermocycled between five and 55 degrees Celsius for 1,000 cycles, stained with two percent basic fuchsin, sectioned, and visually inspected for microleakage utilizing stereomicroscopy on a four-point scale. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance on ranks using Dunn's method (P<0.05). Results: Microleakage between the two SMART restoration groups was insignificant. SAGI alone demonstrated significantly more microleakage than all other groups. There was no statistical significance between the Fuji IX GP® control group and the two SMART restoration groups. Conclusions: This in vitro study indicated that silver diammine fluoride placed before glass ionomer restoration does not increase microleakage. Polyacrylic acid may be used after SDF placement without increasing microleakage.

Aim of the Study: The study aimed to assess the microleakage of nanoparticle-based (NPB) cyanoacrylate sealer and epoxy resin-based (ERB) sealer using radioisotope method and confocal laser scanning microscopy (CLSM)., Materials and Methods: A total of 100 single-rooted teeth were collected; specimens were accessed, instrumented, and irrigated, and randomly distributed into 4 groups of 25 samples each: Group I: Positive control, group II: Negative control, group III: Obturated with NPB sealer, and group IV: Obturated with ERB sealer. All samples were immersed in 99mTc pertechnetate solution, for 3 hours after which radioactivity was estimated under a Gamma camera. The radioactivity released by specimens before and after nail varnish removal was statistically analyzed. After 2 weeks, the same samples were used for CLSM analysis. The sealer tubular penetration depth was measured at the deepest level for each group using ZEN lite 2012. Data collected was statistically evaluated., Results: The amount of radioactivity observed at first in group III and group IV was 194.76 and 599.12 units, respectively, with p -value < 0.001, indicating significant interaction, and after nail varnish removal, it was 89.68 and 468.44 units, respectively, with a p -value < 0.001; again, indicating statistical significance. Hence, the radioactivity of NPB sealer was found to be lower than ERB sealer in both cases, indicating better sealing of the former. The photomicrographs show that mean value of dye penetration in NPB sealer in first, second, and third segment from apex was 85.06, 75.73, and 66.09, respectively; while in the case of ERB sealer, those were 597.28, 461.17, and 195.68, respectively; with p -value < 0.001; signifying that NPB sealer exhibited higher resistance to microleakage than ERB sealer., Conclusion: The NPB sealer can become a potential root canal sealer in future endodontics due to superior physiochemical properties attributed to the cyanoacrylate and incorporated nanoparticles., Clinical Significance: The study clinically signifies that we can equally use the radioisotopic method along with confocal method while conducting the microleakage studies. In addition, NPB sealer can be an emerging replacement with better properties than gold standard root canal sealers for clinical use. How to cite this article: Shetty C, Qaiser S, Shetty A, et al . Evaluation of Microleakage of Nanoparticle-incorporated Cyanoacrylate Root Canal Sealer Using the Radioisotopic Method: An In Vitro Study. J Contemp Dent Pract 2024;25(4):335-341.

Purpose: The objective of this study was to assess the microleakage and flexural strength of glass ionomer cement (GIC) and modified GIC (Zirconomer) when coated with protective coating agents such as COAT-IT and G-COAT plus., Methods: Sixty tooth specimens were grouped into two groups based on the type of restorations (GIC (n = 30) and Zirconomer (n = 30)). The samples were further divided into three subgroups (n = 10) based on the protective coating agent (Petroleum jelly, G-COAT Plus, or COAT IT) applied. This study evaluated the microleakage at the occlusal and cervical margins of class V restoration after being subjected to dye penetration and sectioning. Each specimen was viewed under a 40 × microscope and was given scores based on the depth of dye penetration. They were statistically analyzed using the Kruskal-Wallis test and compared within the groups using the Mann- Whitney Test. In addition, flexural strength was assessed using standardized cuboid (25 × 2 × 2 mm) specimens of restorative materials with and without protective coating agents. The mean flexural strength data of all the subgroups were statistically evaluated using a one-way analysis of variance (ANOVA) and compared within the subgroups using the student t test., Results: A statistically significant difference was found when occlusal margin microleakage scores were evaluated with G-COAT Plus demonstrating the lowest occlusal margin microleakage when applied over GIC restoration. The increasing order of occlusal margin microleakage scores is as follows: GIC with G-COAT Plus, Zirconomer with COAT-IT, GIC with COAT-IT, GIC, Zirconomer with G-COAT Plus, and Zirconomer. However, the cervical margin microleakage scores revealed no significant difference. While flexural strength was found to be highest for the GIC group coated with G-COAT Plus, it was observed that there was a significant improvement in the flexural strength of both GIC and Zirconomer when coated with either of the protective coating agents., Conclusion: Within the limitations of this in vitro study, it was observed that the application of protective coating agents can significantly reduce the potential microleakage and improve the flexural strength of the restorative material especially when zirconia-reinforced GIC is the restorative material., (© 2023. The Author(s), under exclusive licence to European Academy of Paediatric Dentistry.)

Aim: This study aimed to evaluate the marginal microleakage and maximum occlusal fracture loads and fracture modes of two novel class II preparation designs, "infinity edge" and the "2.5 mm cusp reduction" preparations as compared to a traditional class II preparation without cuspal involvement., Materials and Methods: Thirty extracted human mandibular molars were prepared for moderate-sized class II restorations with extensions into all occlusal grooves. Of these, ten class II preparations served as control. Ten were modified for a 2.5 mm even reduction of the cusps adjacent to the interproximal box. An additional 10 preparations were modified with an "infinity edge" bevel on the interproximal and occlusal portions. All teeth were restored utilizing a flowable bulk-fill composite in the apical portion of the interproximal box and 2-4 mm of heated bulk-fill composite in one increment for the remainder. All groups were cyclic loaded and thermocycled, then imaged with microcomputed tomography (µCT) before and after infiltration with a silver nitrate solution. Images were subtracted to obtain volumetric measurements of microleakage and reported as a percentage of the total volume from the apical extent of the proximal box. All groups were loaded to failure and fracture load and mode were recorded., Results: No significant differences were found in microleakage volume as a percentage of total tooth volume; however, the "infinity edge" group had significantly greater microleakage in the proximal box compared to the traditional class II group. No significant differences were found in fracture load or mode between the groups., Conclusion: Traditional class II, 2.5 mm cuspal reduction, and "infinity edge" preparation designs have similar fracture loads as well as volumes of microleakage; however, an "infinity edge" preparation has a higher ratio of microleakage in the proximal box., Clinical Significance: Clinicians should carefully consider the use of "infinity edge" margins, particularly on dentin in the apical extent of the proximal box. How to cite this article: Watson JC, Lien W, Raimondi JC, et al . In Vitro Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites. J Contemp Dent Pract 2024;25(1):3-9.

Pit and fissure sealants play an essential role in preventive dentistry. This study evaluates the microleakage levels of a new and colored flowable composite applied as a sealant after three preparation techniques. A total of 24 non-carious mandibular permanent molars with deep pits and fissures were included in the study. Pit and fissures were prepared with 37% phosphoric acid, tungsten carbide bur and fissurotomy burs (SS WHITE Dental, New Jersey, USA) using conventional, enameloplasty and fissurotomy techniques. All samples were thermocycled following the placement of Rainbow Flow (PPH CERKAMED Wojciech Pawłowski, Poland) as a sealant and sections were taken after immersion in methylene blue dye. The microleakage levels of the samples were examined under a stereomicroscope (Olympus SZX-7 Olympus SZ-61 Stereo Microscope) at 2.8× magnification to analyze the dye penetration of the flowable composite. The 144 sections were examined and scoring for microleakage was done by examining the dye penetration from the occlusal border to the base of the fissure. Considering all sections regardless of the preparation technique, it was found that 16.6% of the sections have no leakage. Regarding the microleakage scores, the mean score of the conventional group was 1.87 ± 0.98, the mean score of the enameloplasty group was 1.88 ± 1.14, and the mean score of the fissurotomy group was 1.81 ± 1.1. The median scores of the conventional, enameloplasty and fissurotomy groups were 2, 2 and 1.5, respectively. The present study reports no difference between the microleakage level of a colored flowable composite material used as a pit and fissure sealant following three fissure preparation techniques and supports the clinical use of this material., Competing Interests: The authors declare no conflict of interest., (©2023 The Author(s). Published by MRE Press.)

Aims: This systematic review aimed to compare the efficiency of orifice barriers in preventing coronal microleakage in vitro., Methods: Articles published in English, German and Chinese were searched for studies describing microleakage assays for the bacterial penetration of root canal-treated teeth in vitro. The final sample included 18 articles for review and meta-analysis. Risk ratios and confidence intervals were determined for dichotomous variables. Ten publications using bacterial leakage models contributed to the meta-analysis., Results: The addition of orifice barriers to a root canal filling was overall effective, shown by risk ratios (RR) and 95% confidence intervals (CI) demonstrating reduced microleakage with glass ionomer cement (GIC) (RR 0.37, 95% CI 0.26-0.53, P < 0.001), resin-modified GIC (RR 0.32, 95% CI 0.15-0.67, P = 0.01), composite resin (RR 0.54, 95% CI 0.38-0.75, P < 0.001), mineral trioxide aggregate (MTA) (RR 0.25, 95% CI 0.12-0.52, P < 0.001) and Cavit (RR 0.23, 95% CI 0.14-0.39, P < 0.001). There were no significant differences between GIC, resin-modified GIC, composite resin and MTA orifice barriers., Conclusions: Placement of an orifice barrier over the root canal filling is effective in the prevention of coronal microleakage in vitro. Other parameters may also affect the effectiveness of orifice barriers, including thickness and duration of exposure to the oral environment. © 2023 Australian Dental Association., (© 2023 The Authors. Australian Dental Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Dental Association.)

Purpose: To test a newly introduced implant-abutment material combination against bacterial endotoxin leakage in a human whole blood assay., Materials and Methods: Two dental implant systems with internal connections and the following material combinations at the implant-abutment interface (IAI) were used (implant material/abutment material): yttrium-stabilized tetragonal zirconium dioxide (Y-TZP)/polyetherketoneketone (PEKK), and titanium (Ti/Ti). Test implants were inoculated with lipopolysaccharide (LPS) and sealed and submerged in human whole blood. Untreated implants served as the control groups. Changes in gene expression levels of inflammatory markers indicating LPS leakage were assessed after 1, 8, and 24 hours using quantitative real-time polymerase chain reaction., Results: In the Y-TZP/PEKK test group, a significant influence of the implant system (P < .001) on increases in gene expression indicating leakage were detected after 8 hours for TLR-4 and after 24 hours for interleukin 1-β and nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB), indicating microleakage of LPS at the IAI. In the Ti/Ti test group, differences in gene expression were found only for NF-κB after 8 hours., Conclusion: The internal hexalobe IAI of two-piece dental implants fabricated from Y-TZP and PEKK do not prevent LPS molecular microleakage.

The aim of this systematic review is to evaluate the effectiveness of different materials used for sealing dental implant abutment screw access channel (ASAC), in preventing microleakage. As per the searched indexed English literature, this study is the first review of its kind. Indexed English literature published up to February 20, 2021 was systematically searched on relevant electronic databases. The recommendations specified by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) were applied for constructing framework, and reporting the current review. The focused PICO (Participant, Intervention, Comparison, Outcome) question was: "Which material (C) is more effective in sealing (I) implant ASAC (P) in terms of causing minimal microbial leakage (O)". Quality of articles was assessed with modified CONSORT scale for in vitro studies. Five in vitro studies were selected for qualitative analysis after final stage screening. Modified CONSORT scale suggested that out of the 5 selected studies, 1 each was of low and high quality, whereas 3 studies were of moderate quality. Included studies had contrasting results related to the efficacy these materials as sealants in ASAC. Sealing capacity against microleakage should be considered as one of the important criteria while selecting the material to fill implant ASAC. Definitive conclusions asserting superiority of a single material over others are difficult to draw, due to nonhomogeneity in study design of the included papers. More studies should be conducted in the near future to investigate the efficacy of various combination of materials in preventing microleakage.

Aim: The aim of the study was to investigate the influence of cavity cleaning and conditioning on marginal integrity of directly placed post-endodontic composite class-I-restorations in vitro., Methodology: A total of 168 fully intact teeth without caries or fillings received pre-endodontic composite restorations (class-II) after their extraction. Occlusal endodontic access-cavities were prepared, and root canals were instrumented and filled with gutta-percha and an epoxy resin-based sealer. Prior to post-endodontic class-I-restoration, access cavities were completely contaminated with sealer, cleaned with alcohol and pre-treated as follows: cleaner only (alcohol), glycine-polishing, Al 2 O 3 sandblasting, carbide bur (immediate as well as delayed restoration). A positive control (not contaminated with sealer and adhesive used) and negative control (cleaner used but no adhesive) were established. Half of the teeth from each group were subjected to thermocycling and mechanical loading (TCML). Marginal integrity of post-endodontic restoration was evaluated in oro-vestibular or mesio-distal sections after AgNO 3 dye penetration (DP) by standardized photomacroscopic imaging and expressed in per cent of margin length along all segments and separately for enamel, dentine and composite, respectively. Results were analysed non-parametrically (α = .05)., Results: No restorations or teeth fractured or debonded completely. Without TCML, the median DP of all segments was significantly higher for the negative control compared with all other groups in oro-vestibular cutting direction (53%; p = .002) and in mesio-distal cutting direction (51%; p ≤ .041). The other groups without TCML revealed 16%-24% DP (oro-vestibular) and 12%-24% DP (mesio-distal). With TCML, the median DP in oro-vestibular cutting direction for all segments ranged between 48% and 62% for all groups, a significant difference was only observed between glycine-polishing and carbide bur (p = .041). In mesio-distal cutting direction, the median DP in negative control was 69% with TCML and significantly higher compared with all other groups (p = .002). For all other groups, the median DP of all segments ranged between 28% and 40% with TCML without significant differences. Error rates method (k = 7) revealed a significant influence of TCML in general on penetration of all segments in both oro-vestibular and mesio-distal cutting directions., Conclusion: Additional access cavity pre-treatment after alcohol cleaning did not improve the marginal integrity of post-endodontic composite restorations. Thorough cleaning of the access cavity with alcohol seems to assure an acceptable marginal integrity to the tooth and restorative composite., (© 2022 The Authors. International Endodontic Journal published by John Wiley & Sons Ltd on behalf of British Endodontic Society.)

Aim: Aim of this research was to assess the microbial leakage of restorative materials with/without antibacterial primer as an intracoronal barrier., Materials and Methods: Fifty-five extracted single-rooted teeth were included in this study. The canals were cleaned, shaped, and obturated with gutta-percha and AH plus sealer at the established working length. After removing 2 mm of coronal gutta-percha, the teeth were incubated for 24 hours. The teeth were divided into groups according to the materials used as intracoronary orifice barriers as follows: • Group I: Clearfil Protect Bond/Clearfil AP-X • Group II: Xeno IV/Clearfil AP-X • Group III: Chemflex (glass ionomer) • Group IV: Positive control (no barrier) • Group V: Negative control (no barrier and inoculated with sterile broth) Sterile 2 chambers bacterial technique was used to assess the microleakage and Enterococcus faecalis was considered as a microbial marker. The percentage of samples leaked, the time taken for leakage, and the number of colony-forming units (CFUs) in the leaked samples were calculated and analyzed statistically., Results: There was no statistically significant difference found in bacterial penetration among the three investigated materials after 120 days of use as an intracoronal orifice barrier. This study can also infer that the leaked sample from the Clearfil Protect Bond showed the least mean number of CFUs (43 CFUs) followed by Xeno IV (61 CFUs) and glass ionomer cement (GIC) (63 CFUs)., Conclusion: This study concluded that all three experimental antibacterial primers performed better as intracoronal barrier. However, Clearfil Protect Bond with an antibacterial primer showed promising results as an intracoronal orifice barrier in reducing the number of bacterial leakages., Clinical Significance: The significance of intracoronal orifice barriers in the success of endodontic treatment depends on the ability of the materials to prevent microleakage. This helps clinicians to provide successful antibacterial therapy against endodontic anaerobes.

Aim: The aim of the study was to compare the sealing ability of Mineral Trioxide Aggregate (MTA) and Retroplast as root end filling materials using the Rhodamine B dye penetration method in vitro., Methodology: Forty freshly extracted human single-rooted teeth were randomly divided into two groups of 20 teeth each, and standard root-end cavities were prepared in all teeth. The cavities were filled with MTA and Retroplast in groups 1 and 2, respectively. The specimens were then stored in 1% Rhodamine B dye for a week, following which the dye penetration with all samples was analysed under a stereomicroscope and scored according to Tronstad's criteria. The observations were compared with Chi square test at a 0.220 level of significance., Results: 5% of the samples in both the groups showed no significant leakage. The leakage was deeper with the Retroplast group than with the MTA group; however, there was no statistically significant difference between the two groups., Conclusion: Both MTA and Retroplast are similar in their sealing potential as root-end cavity fillings with Retroplast reporting slightly deeper microleakage than MTA within the limits of the present study., Competing Interests: None

The present study aims to characterize, for the first time, the microgap and bacterial microleakage of a platform-switched implant system with hybrid connection, screwed at distinct torque values (manufacturer recommended torque-25 N cm-and a reduced torque-5 N cm-mimicking the long-term functional use), in the absence or presence of a silicon-based sealing agent. Microgap was determined through scanning electron microscopy and bacterial microleakage was evaluated in vitro, upon Enterococcus faecalis colonization of the system. The sealing efficacy was evaluated in the absence or presence of a commercially available silicon-based sealer. The cytotoxicity of the sealer was further addressed in vitro, with a fibroblastic cell line, in accordance with reference standards. A low microgap of the implant system was verified, regardless of the applied torque load-maximal values ranged around 0.25 and 1.25 µm, for 25 and 5 N cm torques, respectively. No bacterial microleakage was reported at 25 N cm, while at 5 N cm, leakage was verified on 38% of the samples. The application of a silicon-based sealer-with an adequate cytocompatible profile-was effective on preventing the bacterial microleakage on the assayed experimental setting. The assayed platform-switched implant system with hybrid connection presented a low interfacial misfit and an effective sealing capability at manufacturer recommended torque. Despite the increased microleakage at low torque conditions, the application of a cytocompatible silicon-based sealing agent restored the sealing effectiveness of the system. The use of a silicon-based sealing agent can assist on the maintenance of the sealing effectiveness even at low torque conditions., (© 2021. The Society of The Nippon Dental University.)

Aim: This study aimed to investigate the conditioning effects of phosphoric acid/5.25% sodium hypochlorite (NaOCl) mixture, 2% chlorhexidine (CHX) digluconate, and 10% polyacrylic acid on cavosurface microleakage and bond strength of glass ionomer (GI) restorations., Materials and Methods: Out of 68 extracted premolars, 34 teeth were selected for microleakage and 34 for bond strength evaluation. The samples were divided into the following four groups. Group 1: pretreatment with 50/50 volume% mixture of 5.25% NaOCl solution and 37% phosphoric acid (H 3 PO 4 ), Group 2:pretreatment with 2% CHX digluconate, Group 3: pretreatment with 10% polyacrylic acid (positive control), and Group 4: no pretreatment (negative control). All the samples were then restored with glass ionomer cement (GIC). Microleakage was evaluated using a stereomicroscope and rhodamine-B dye penetration test. For bond strength, flat dentin surface was exposed and pretreated as mentioned previously and restored with GIC and was evaluated using universal testing machine., Results: Among all the four groups, Group 1 showed least microleakage and highest bond strength when compared with other groups. Whereas the Group 4 samples which were not pretreated with any of the conditioning agent showed the least shear bond strength with greatest cavosurface microleakage when compared to the groups which were pretreated with the conditioning agents., Conclusions: A combination of 50/50 volume % mixture of 37% H 3 PO 4 and 5.25% NaOCl can be a good choice for surface pretreatment of GI restorations., Competing Interests: None

Objectives: This study aimed to assess the enamel and dentin marginal microleakage and dentin microtensile bond strength (μTBS) of ACTIVA BioACTIVE Restorative with and without a bonding agent compared with conventional restorative materials., Material and Methods: For enamel and dentin microleakage, Class II boxes were prepared in the mesial (1 mm under the cementoenamel junction) and distal (1 mm above the cementoenamel junction) surfaces of 90 extracted human third molars. The teeth were randomly divided into five groups (n = 18): Group Z (G-Premio Bond + Filtek Z250 XT), Group X (G-Premio Bond + X-tra fil bulk-fill), Group AA (G-Premio Bond + Activa Bioactive restorative), Group A (Activa Bioactive restorative), and Group G (dentin conditioner + Fuji II LC Improve). The teeth were thermocycled, and their microleakage was quantified using the dye penetration test under a stereomicroscope. For dentin μTBS measurement, 12 specimens were fabricated in metal molds (1 × 1 × 12 mm³) for each group mentioned above, and a universal testing machine measured their μTBS. Data were analyzed using one-way analysis of variance (ANOVA), the Kruskal-Wallis test, and multiple comparisons tests., Results: Significant differences were noted among the groups in marginal microleakage and μTBS (p < .001). The highest mean microleakage scores at the enamel and dentin margins were noted in Group A, which had significant differences with other groups (p < .001). The highest μTBS was found in Group X, with significant differences with Group G and Group A (p < .05). The lowest µTBS was noted in Group A, with significant differences with Groups X, Group AA, and Group Z (p < .001)., Conclusions: Activa Bioactive without a bonding agent showed significantly lower µTBS to dentin, and higher microleakage at the enamel and dentin margins. Application of adhesive resin with Activa Bioactive provided a dentine bond strength and marginal seal comparable to other restorative materials., (© 2022 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

PURPOSE：To evaluate the effect of different pretreatment methods on dentin microleakage and bonding effect of caries, so as to provide reference for clinical practice., Methods: Sixty isolated caries were collected from Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital of Nanchang University from January 2020 to December 2020, and 120 dental samples were obtained by grinding them into two halves along the long axis of the precursor teeth. According to different pretreatment methods, they were divided into group A (2%NaClO), group B (2% chlorhexidine) and group C (75% ethanol). The bond strength, microtensile test and microleakage of the three groups of teeth were compared. SPSS 24.0 software package was used for statistical analysis of the data., Results: The bond strength of the three groups from high to low was group A, group B and group C(P＜0.05); the fracture type of the three groups was compared, mixed damage of group A was lower than that of group B and group C； microleakage of the three groups was compared, and microleakage of group A was better than that of group B and group C(P＜0.05)., Conclusions: Pre-treatment with 2%NaClO can reduce dentin microleakage and significantly improve the bonding strength of teeth, which is conducive to the promotion and application in the treatment of dental diseases.

Background: Successful endodontic therapy requires prevention of bacterial leakage between the root canal filing and root-canal walls. Sealing quality of a root canal filling depends strongly on the sealing ability of the sealer used. The present study aimed to evaluate the bacterial leakage resistance of AH Plus sealer modified with silver nanoparticles., Methods: Forty sound teeth were obturated using lateral compaction technique except for five teeth as the negative controls. After considering five teeth as the positive controls (filled without sealer), the remaining teeth were assigned to two groups (n = 15) in terms of the sealer used (AH Plus sealer and silver nanoparticle-modified AH Plus). Bacterial leakage was evaluated in saliva using the two-chamber technique in every 24 h. When all the samples in the test groups were contaminated, the study was terminated. The data were analyzed with log-rank statistical test., Results: All samples in both experimental groups were contaminated during the 3-months period of observation. There was no significant difference in contamination time between study groups (P > 0.05)., Conclusions: Silver nanoparticles used in tested concentration did not improve the bacterial leakage resistance of AH Plus sealer., (© 2021. The Author(s).)

Objectives: Microleakage is a determinant factor of failures in sealant application. In this study, DMAEM (dodecylmethylaminoethyl methacrylate), a pH-responsive antibacterial agent, was incorporated into resin-based sealant for the first time. The objectives of this study were to: (1) investigate the long-term performance of DMAEM-modified sealants against oral microbial-aging; and (2) investigate the long-term preventive effect of DMAEM-modified sealants on microleakage., Methods: Depth-of-cure and cytotoxicity of DMAEM-modified sealants were measured. Then, an aging model using biofilm derived from the saliva of high caries experience children was conducted. After aging, microhardness and surface roughness were measured. Biofilm activity, lactic acid production and exopolysaccharide (EPS) production were measured. 16S rRNA gene sequencing were also performed. The effects of DMAEM on microleakage were tested using an in vitro microleakage assessment., Results: The addition of DMAEM with a mass fraction of 2.5-10% did not affect depth-of-cure values and cytotoxicity of sealants. Adding 2.5-10% DMAEM did not affect the surface roughness and microhardness after aging. Compared to control, adding 2.5-10% DMAEM reduced biofilm metabolic activity by more than 80%. The lactic acid production and EPS production were reduced by 50% in DMAEM groups. DMAEM-modified sealants maintained the microbial diversity of biofilm after aging, they also inhibited the growth of lactobacillus. The 5% and 10% DMAEM groups exhibited a significant reduction in microleakage compared to control., Significance: The long-term antibacterial activities against oral microbial-aging and the long-term microecosystem-regulating capabilities enabled DMAEM-modified sealant to prevent microleakage in sealant application and thus prevent dental caries., (Copyright © 2021 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Background: It is still not fully understood what pretreatment is best for achieving maximum tightness for pit and fissure sealings (PFS)., Aim: This study investigated microleakage of PFS placed after etching with phosphoric acid or after the application of self-etching primers/adhesives (SEPA)., Design: 131 third molars were assigned to ten groups. In Hel-P, Helioseal® was applied after phosphoric acid etching. In the other groups, SEPA were used (Dyr-AP: Adper™ Prompt™ L-Pop™, Dyract® Seal; Bea: BeautiSealant Primer and Paste; Hel-Exp: Experimental primer, Helioseal®; Hel-Cl: Clearfil™ SE Bond 1 , Helioseal®). Specimens were stored in distilled water at 37°C (28 days), followed by 3500 thermocycles and staining with 5% methylene blue (M) or 5% silver nitrate (S). After methylene blue staining and sectioning, microleakage was assessed light microscopically. During silver nitrate staining, specimens were dissolved by 32% HCl and remaining PFS were evaluated under a SEM., Results: Tightness, percentage of penetrated area, and maximum dye penetration were best for Hel-P and Hel-Cl (p < 0.05)., Conclusions: Phosphoric acid etching of enamel and Clearfil™ SE Bond resulted in the best sealing quality. Methylene blue staining allowed the evaluation of more criteria (fissure shape, voids, sealant penetration depth) compared to silver nitrate., (© 2021 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

Aim and Objective: The aim of this study was to evaluate the depth of penetration as well as the microleakage of three different pit and fissure sealant materials employing the dye penetration method., Materials and Methods: Sixty healthy human mandibular premolar teeth without dental caries that were extracted for orthodontic treatment constituted the study samples. These 60 premolar samples were subjected to an equal division (20 in every group) into three groups. Group I: self-adhering flowable composite, group II: flowable nanocomposites, group III: classical pit and fissure sealants. Every sample tooth underwent thermocycling amid 4°C ± 2°C and 60°C ± 2°C for 1,000 cycles. The samples were placed in 1% methylene blue solution for 24 hours to permit diffusion of the dye into probable gaps in between the restoration and the tooth. The teeth were sectioned and evaluated below a stereomicroscope at 10× magnification with image analysis software., Results: Flowable nanocomposites (3.69 ± 0.10) exhibited a slightly greater mean depth of penetration as compared to classical pit and fissure sealants (3.58 ± 0.16) and self-adhering flowable composites (3.51 ± 0.13) in that order. This difference between the three sealants was not significant statistical. Amid the three sealant study groups, the lowest mean marginal microleakage was exhibited by the flowable nanocomposites (1.06 ± 0.03), followed by self-adhering flowable composites (1.98 ± 0.06), and classical pit and fissure sealants (2.74 ± 0.11). Analysis of variance revealed statistically significant differences among the three sealants that were studied., Conclusion: This study concludes that flowable nanocomposites depicted enhanced penetration and reduced marginal leakage as compared to the self-adhering flowable composites and classical pit and fissure sealants., Clinical Significance: An efficient approach to preventing dental caries on the occlusal surfaces of teeth is the use of pit and fissure sealants. The efficiency of sealants chiefly depends on the morphological characteristics of the fissures and properties of dental materials used.

Background: This in-vitro study aimed to investigate the effect of two different antibacterial disinfectants on the microleakage performance of newly developed bulk-fill composite, bonded to different tooth structures., Methods: Class V cavities were prepared in 30 sound premolar teeth, with enamel occlusal margins (OM) and dentin cervical margins (CM). Two disinfectants, 2% chlorhexidine gluconate (CHX) and Listerine Miswak (ListM), were used. Teeth were divided into three groups (n = 10): G1, Control; G2, CHX; and G3, ListM. Disinfectants were applied to the cavity preparation walls after they were etched with 35% phosphoric acid. The Single Bond Universal adhesive system was then used, and teeth were restored with Filtek One Bulk Fill composite. Samples were examined, after thermocycling aging, by stereomicroscopy for the evaluation of marginal dye penetration., Results: The highest mean microleakage score was reported in the CM of G1 (2.60 ± 1.174), which was significant compared with that of G2 only (p = 0.02). OM in G1 showed no microleakage, with no significant differences found among groups (χ 2  = 1.39, p = 0.50). No significant differences were reported between G2 and G3 (p = 0.45 OM; p = 0.17 CM)., Conclusions: Cavity pretreatment with CHX is not significantly different to pretreatment with CHX. In contrast, CHX improved the cervical marginal seal as compare to the control group (G1)., (© 2021. The Author(s).)

Aim: The purpose of this in vitro study was to evaluate the intraorifice sealing ability of light-cured glass-ionomer cement (LC-GIC), Tetric N-Flow, and ProRoot mineral trioxide aggregate (MTA) against Enterococcus faecalis and Proteus vulgaris ., Materials and Methods: Crowns of the eighty human mandibular teeth were decapitated. Working length determination was performed, after which cleaning and shaping were carried out. A uniform orifice diameter of 1.3 mm, at its widest point, was made. Once instrumentation was completed, the canals were irrigated and then obturated. A heat carrier was used to remove gutta-percha to the depth of 3.5 mm. Samples were then divided into a control group (Group 1) with no barrier, and three groups, namely, Group 2, Group 3, and Group 4, were restored with the LC-GIC, Tetric N-Flow, and ProRoot MTA, respectively. The groups were further subdivided into Subgroup A for checking bacterial leakage against E. faecalis and Subgroup B, against P. vulgaris . All samples were subjected to the bacterial leakage test and observed daily for the appearance of turbidity after which statistical analysis was performed., Results: Group 1 showed leakage in, as early as, 3 days. The longest time for the turbidity to appear was shown by Group 4 with an average of 31 days. The mean number of days for turbidity to appear in Group 2 and Group 3 was 23 and 24 days, respectively. Group 4 showed the best intraorifice sealing ability with a significant difference., Conclusion: The teeth with an intraorifice coronal seal had better protection against microbial leakage. Among all materials used, the ProRoot MTA showed the best intraorifice sealing ability., Clinical Significance: Use of the ProRoot MTA promises long-term results in the endodontically treated teeth as compared with other materials.

Aim: The purpose of this study was to evaluate 2% chlorhexidine disinfectant (CHX), chitosan, and octenidine dihydrochloride (as cavity disinfectants) on microleakage in cavities restored with universal self-etch adhesive., Materials and Methods: Eighty extracted human permanent premolars were selected. Class V cavities were prepared on the facial surface of each tooth. The teeth were then divided into four groups of 20 teeth each. For the control group after cavity preparation, no disinfectant was applied. The other 3 groups were treated with 0.1% chitosan, 2% CHX, and 0.1% octenidine dihydrochloride (OCT). All the groups were restored with universal adhesive followed by composite resin. The teeth were then immersed in 1% methylene blue dye and were sectioned buccolingually. Microleakage was checked under a stereomicroscope on both occlusal and gingival margins., Result: Among all the groups chitosan-treated cavities showed the least microleakage. Chlorhexidine treated cavities showed less leakage as compared to control, OCT group at both the margins., Conclusion: Chitosan as a cavity disinfectant improves the sealing ability of the self-etch adhesive. Furthermore, in vivo studies need to be conducted to examine the interaction and long-term effect of chitosan with the other self-etch adhesive systems., Clinical Significance: Chitosan a natural polysaccharide can be used as a cavity disinfectant as it improves the sealing ability of self-etch adhesive.

BACKGROUND Successful endodontic therapy requires a fluid-tight apical seal. The aim of this in vitro study was to evaluate and compare the apical sealing ability of 3 root canal sealers: Apexit Plus, AH Plus, and Resilon/Epiphany sealers. MATERIAL AND METHODS Samples of 152 single-rooted teeth were divided into 2 test groups, and each group was divided into 3 subgroups based on the preparation and obturation technique. After preparation with the step-back technique, the first group of root canals were obturated with lateral gutta-percha compaction in combination with AH Plus sealer or Apexit Plus or with the Resilon/Epiphany system alone. In the second group, preparation was done with the crown-down technique and root canals were then obturated with Thermafil obturator in combination with AH Plus or Apexit Plus or with Resilon/Epiphany sealer alone. Apical leakage was determined using a dye leakage test observed with a stereomicroscope. The degree of dye leakage was assessed using the t test to comparing the arithmetic averages of the groups. RESULTS In the groups prepared with the step-back technique, the average dye leakage was lower in samples obturated with Resilon/Epiphany, than in those filled with AH Plus/lateral gutta-percha compaction or Apexit Plus/lateral gutta-percha compaction. In groups prepared with the crown-down technique and obturated with the Resilon/Epiphany system, the average dye leakage was lower than in those filled with AH Plus/Thermafil obturation and those filled with Apexit Plus/Thermafil obturation. CONCLUSIONS Although all preparation and obturation techniques showed dye penetration, the crown-down technique paired with the Resilon/Epiphany system showed the least leakage.

Background: As the member of erbium laser family, Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) has obtained the approval for caries removal and cavity preparation by Food and Drug Administration (FDA). However, there is still controversy over the beneficial effects of Er,Cr:YSGG preparations on microleakage. The present study is the first systematic review and meta-analysis to compare the microleakage of cavities prepared by Er,Cr:YSGG lasers with that by traditional burs. In addition, the effect of acid etching on the adhesive potential of self-etch and etch-and-rinse adhesives was assessed after laser preparation., Methods: An electronic search was performed in Pubmed, EBSCO, Embase, and the Cochrane Controlled Register of Trials (CENTRAL)., Results: Totally, 357 articles were identified. Finally, 13 met the inclusion criteria, of which 11 were selected for meta-analysis. All the included studies exhibited a moderate risk of bias. Based on the meta-analysis, no significant difference was observed between the Er,Cr:YSGG and traditional bur groups in terms of the incidence of microleakage. Self-etch adhesives, in combination with prior acid etching, showed less microleakage than those without acid etching in the laser-prepared cavities., Conclusions: Current studies do not support the beneficial effects of Er,Cr:YSGG preparations on microleakage. Additional acid etching with self-etching adhesives is recommended after Er,Cr:YSGG preparations. Further high-quality studies are needed to draw a convincing conclusion in the future.

Purpose: To evaluate the effect of different enamel conditioning protocols and their re-application on the microleakage of fissure sealants placed following saliva contamination., Study Design: The study included 156 human third molars in 16 subgroups (2×4×2) under two main groups (sealant type): Group A- hydrophobic resin sealant, 3M Clinpro™ Sealant; Group B- hydrophilic resin sealant, Ultraseal XT Hydro. Each group was then divided according to the type of surface conditioning; 1- Er,Cr:YSSG laser etching, 2- acid-etching, 3- acid-etching+etch-and-rinse adhesive (Prime&Bond® One Select) and 4- self-etching adhesive (Clearfil™ SE Bond). After contaminating the conditioned occlusal enamel surfaces with artificial saliva, fissure sealant was applied in half of the specimens (a), whereas in the other half, (b) the respective surface conditioning was repeated and then fissure sealant was placed. Following thermocycling, the samples were immersed in basic fuchsin, sectioned, and dye penetration was quantitatively assessed with ImageJ. Two-way ANOVA and Bonferroni post-hoc tests were used for statistical analyses (p<0.05)., Results: The least microleakage was observed in A3b and A3a, whereas B4b and B4a were the subgroups with the highest microleakage. Following saliva contamination, when surface conditioning was not re-applied, the effects of fissure sealant types and surface conditioning were significant (p=0.005 and p<0.001, respectively). However, their interaction was insignificant (p=0.173). When surface conditioning was re-applied after saliva contamination, the effects of type of fissure sealant and surface conditioning (p=0.000, for both) and their interaction (p=0.004) were significant., Conclusions: 3M Clinpro™ Sealant was superior to Ultraseal XT Hydro. Re-application of Er,Cr:YSSG laser and the self-etching adhesive did not affect the microleakage of both fissure sealants. Without re-application, acid-etching+etch-and-rinse adhesive was superior to acid-etching only. However, both of them were similarly successful when they were re-applied following saliva contamination.

The aim of this study was to assess the influence of different pre-treatment approaches on glass ionomer cement (GIC) bond strength (BS) to dentine. Sixty bovine incisors were allocated into six groups according to substrate - sound or caries-affected dentine; and substrate pre-treatment approach - no conditioning (control), polyacrylic acid for 10 s and phosphoric acid for 7 s. Teeth in the caries-affected dentine group were previously submitted to cariogenic pH-cycling challenge. After dentine pre-treatment, according to experimental groups, polyethylene tubes were placed on flat dentine surfaces and filled with GIC. Teeth were stored in distilled water for 24 h at 37 °C and then submitted to microshear test (0.5 mm/min). Failure pattern analysis was performed under stereomicroscope (400x). Data were analysed using two-way ANOVA and Tukey's test (α=5%). Statistically significant differences were found for the pre-treatment approach, regardless of substrate (p<0.001). The polyacrylic acid group and control group had similar BS values, and were both better than the phosphoric acid group. In general, GIC had better bonding performance in sound dentine than in caries-affected dentine. In conclusion, dentine pre-treatment with polyacrylic acid did not improve the performance of GIC restoration on clinically relevant substrates.

Background: Smear layer removal has been shown to reduce bacterial penetration through root canal obturations when resin-based endodontic sealer is used. The purpose of this in vitro study was to test this effect when a non-resin-based sealer is used., Material and Methods: Thirty root segments were assigned to the following groups: Smear layer removed (n = 8); smear layer retained (n = 8); negative controls (n = 10; 5 with smear layer, 5 without); and positive controls (n = 4; 2 with smear layer, 2 without). After rotary instrumentation, smear layers were removed in the treatment group and half of controls using 17% ethylenediamenetetraacetic acid (EDTA) prior to obturation. Each obturated root was affixed into a dual-chamber leakage model employing Streptococcus mutans. Roots were incubated at 37 °C for 120 d. Days until lower chamber turbidity occurred was recorded for each sample, and data were analyzed using Kaplan-Meier survival curve analysis (p = 0.05)., Results: No negative controls leaked, while all positive controls were turbid within 1 day. Mean days to leakage for roots with smear layer intact was 82.75 (+/- 33.29, 95% CI), although three never leaked. Mean days to leakage through roots with smear layer removed was 46.25 (+/- 26.67, 95% CI), and all leaked. Treatment survival curves were significantly different (p = 0.048)., Conclusions: Under the conditions and limitations of this study, retaining the smear layer reduced the rate of bacterial penetration through canals which had been obturated using zinc oxide eugenol (ZOE) -based sealer.

Background: The present study compares the apical microleakage of three different root-end filling materials in which the retrograde cavity is prepared by two different burs., Methods: Eighty extracted single rooted maxillary and mandibular premolars were taken. Root canal treatment was completed. Apical 3 mm of all the teeth were resected with diamond disk. The tooth were divided into four groups with two subgroups for each group containing 10 tooth (N = 10) as: Group IA (Negative Control and IB (Positive Control); Group IIA and IIB: Prepared with round carbide bur and round diamond bur respectively, filled with GIC; Group IIIA and IIIB: Prepared with round carbide bur and round diamond bur respectively, filled with MTA; Group IVA and IVB: Prepared with round carbide bur and round diamond bur, filled with Biodentine. After applying two coats of nail varnish leaving apical 3 mm (except for negative control group) all teeth were immersed in 2% methylene blue for 3 days and again in 65% nitric acid for next 3 days for extraction of dye. The obtained solution was then transferred to eppendorf tube and centrifuged in microcentrifuges at 14,000 revolution per minutes (RPM) for 5 min. Optical density or absorbance of the supernatant solution was measured with UV spectrophotometer at 550 nm., Results: The absorbance of the supernatant solution after dye extraction is decreasing in the order of positive control> GIC > MTA > Biodentine> negative control group. The significant difference was observed between GIC and MTA (p = 0.0001) and GIC and Biodentine (p = 0.0001) with two different burs but statistically non-significant difference was observed between MTA and Biodentine with Carbide bur (p = 0.127) and Diamond bur (p = 0.496) respectively., Conclusions: Within the limitations of the present study, it can be concluded that Biodentine and MTA showed less microleakage as compared to GIC. There is no significant difference between mean microleakage of MTA and Biodentine. However, the mean OD of the Biodentine was least of all evaluated materials. Preparation of the root-end using round carbide bur as well as round diamond burs showed comparable microleakage for all three filling materials.

Osseointegrated dental implants showed elevated success rates on the long-term treatment in the last ten years. However, the risk of peri-implantitis and implant failure is the main complication of implantology. The presence of a micro gap at the implant-abutment connection (IAC) allows microorganisms to penetrate and colonize the inner part of the implant leading to biofilm accumulation and consequently to peri-implantitis development. Some chemical devices (CD) has been studied to reduce bacterial penetration at IAC level but no one have been demonstrated to be effective for this purpose. Aim of the present study is to evaluate the effectiveness of a new chemical formulation STCX-1, placed in the internal part of dental implants for killing bacteria present in the IAC. To identify the antibacterial power of SXTC-1 at interface between implant-abutment connection, the passage of genetically modified Escherichia coli across IAC was evaluated. A total of eight implants were used (Edierre Implant System, Edierre SpA, Genova, Italy). The inner side of four out of the eight implants were firstly contaminated with few microliters of pure bacteria, subsequently were treated with SXTC-1 for few second and finally, the antibacterial was replaced with Lysogeny Broth (LB) and antibiotics without bacteria. The remaining four implants were not treated with SXTC-1 and just filled with LB with antibiotics. Bacteria viability was determined by measuring their Optical Density (OD) at 600nm. The analysis revealed that, in untreated implants, bacteria grew (internally and externally) for the first 48 hours, but subsequently they started to dye. In treated implants, instead, bacteria grew just in the space surrounding the device suggesting that, even if bacteria were able to get into, they immediately died thanks to the presence of SXTC-1. The STCX-1 liquid formulation have been demonstrated to be an adjuvant CD effective for prevention of of bacterial colonization at IAC level., (Copyright 2019 Biolife Sas. www.biolifesas.org.)

Osseointegration can be affected by oral conditions; in particular, the micro gap at the implantabutment-connection (IAC) represents a site for dental plaque aggregation favoring bacterial leakage that can increase inflammatory cells at the level of the IAC, causing peri-implantitis. This micro gap, once early colonized, may constitute a bacterial reservoir that could subsequently contaminate fixture's surroundings and interfere with peri-implant tissues health. The aim of this review is to describe, according to the most recent literature, the different kind of implant-abutment connection and their ability to reduce bacterial leakage and thus preventing peri-implantitis. The following database were consulted: Pubmed (n=26), Scopus (n=90), Research gate (n=7) and 123 articles were found. Duplicates were excluded and after reading abstract and titles, those articles that were off topic were also excluded. The remaining ones (n=24) were assessed for full-text eligibility. We excluded 5 articles because they were case reports, 2 because there was no clear reference to the relationship between IAC and bacterial leakage and 2 because they were not pertinent to the argument. Fifteen articles were included in the review. From the review, it is clear that a relationship between the IAC and bacterial leakage exists. All the connections presented an amount of micro-gap and bacterial micro-leakage but conical and mixed connection systems seem to behave better. Moreover, both connections seem to have a better load distribution and the mixed one has anti-rotational properties, very useful during the positioning of the prosthesis., (Copyright 2019 Biolife Sas. www.biolifesas.org.)

Aim: The aim of the present study was to investigate bacterial leakage and marginal adaptation of bioceramic apical plugs., Methods: Extracted human mandibular premolars were prepared to simulate open apex using No. 4 Peeso reamer in retrograde direction. In total, 150 specimens were divided into 10 groups by obturation with five bioceramics in two thicknesses. Groups 1, 3, 5, 7, and 9 were obturated with ProRootMTA, Biodentine, TotalFill BC RRM paste, TotalFill BC RRM putty, and RetroMTA at 3 mm, and groups 2, 4, 6, 8, and 10 were obturated with the same materials at 4 mm. Ten specimens in each group were evaluated for bacterial leakage of Enterococcus faecalis for 75 days. Five specimens from each group were sectioned to investigate the gap area under scanning electron microscope., Results: The 3- and 4-mm Biodentine and TotalFill BC RRM putty groups and the 4-mm ProRootMTA group exhibited less bacterial leakage and lower mean percentage of gap area than those of the other groups. TotalFill BC RRM paste showed the highest leakage for both the 3- and 4-mm groups., Conclusion: The 3- and 4-mm Biodentine and TotalFill BC RRM putty groups and the 4-mm ProRootMTA group exhibited the best sealing ability and marginal adaptation of apical plugs., (© 2018 John Wiley & Sons Australia, Ltd.)

Purpose: To evaluate microleakage in roots restored with fiber posts cemented using three different luting cements, to measure the volume of voids/gaps within the obturated/postcemented root canals, and to examine whether microleakage and the volume of voids/gaps were correlated., Materials and Methods: Thirty-six extracted human mandibular incisors were decoronated, and the root canals were obturated using gutta-percha and sealer in the experimental groups (n = 30). Six roots were used as controls. A standard post space was prepared, and an identically sized fiber post was cemented in each experimental specimen using one of three luting cements (Panavia F2.0, Bifix SE, GC FujiCEM; n = 10 each). The specimens were scanned using micro-computed tomography, and the volume of voids/gaps was determined. The specimens were then subjected to a fluid filtration assay to evaluate microleakage., Results: The volume of voids/gaps was significantly lower in the GC FujiCEM group, and significantly less microleakage occurred in the Bifix SE group compared with other groups (both p < 0.001). A significant correlation between the volume of voids/gaps and leakage was found only in the Panavia F2.0 group (p = 0.003; r = 0.830). No such correlation was found in the analysis of all groups combined., Conclusions: The group with the greatest volume of voids/gaps (Bifix SE) showed the least microleakage, and the group with the smallest volume of voids/gaps (GC FujiCEM) showed the most microleakage. Panavia F2.0 ranked between and exhibited significant correlation., (© 2017 by the American College of Prosthodontists.)

Background: The aim of the study was to assess bacterial sealability and bonding ability of methacrylate-based Resilon (RS, SybronEndo), Endo Rez (ER, Ultradent Products Inc), and epoxy-based AH Plus (AH, Dentsply/DeTrey), MTA Fill Apex (MTAF, Angelus Soluções Odontológicas) root canal sealers, and the effect of the smear layer removal on the sealability., Methods: One hundred thirty root segments were instrumented up to apical size #60 and rinsed with 2.5% NaOCl. Half of the roots were rinsed with 5ml 17% EDTA to remove the smear layer. All the roots were filled with AH, ER, MTAF sealers and gutta-percha, or RS with Resilon cones. After storage at 37°C for 7 days the samples were mounted into bacterial leakage assay for 50 days. Another 100 roots were instrumented and rinsed as described above, split longitudinally, cut into the cervical, middle and apical parts. The sealers were injected through the plastic mould on the dentin surface. After 7 days of incubation at 37°C, bond strength was tested using a notched-edge test fixture (Crosshead, Ultradent Products Inc.) and a universal testing machine (Lloyd Instruments)., Results: AH revealed the longest mean time for bacterial resistance by 29.4 and 36.8 days (with and without smear layer, respectively) followed by RS (15.1 and 24.7 days, respectively). The difference between materials was significant (p<0.001). Bond strength values ranged from 0.2± 0.1 to 3.5± 0.7 MPa and increased from the apical to the cervical third. In the apical third, AH showed the highest mean (SD) bond values 1.4 (0.4) MPa and 1.7 (0.6) MPa (with and without smear, respectively, followed by RS, 0.5 (0.1) MPa and 0.8 (0.1) MPa, respectively. The difference between materials was significant (p=0.001)., Conclusion: The effect of the smear layer removal on the sealability was material-dependent.

Aim: The aim of this in vitro study was to evaluate and compare the effect of protective coating G-Coat Plus on microleakage of conventional glass ionomer cement (CGIC) and resin-modified glass ionomer cement (RMGIC) in primary molars., Materials and Methods: A total of 120 samples were divided into four groups with 30 samples in each group. Group A - teeth restored with CGIC. Group B - teeth restored with CGIC coated with G-Coat Plus. Group C - teeth restored with RMGIC. Group D - teeth restored with RMGIC coated with G-Coat Plus. Microleakage was tested using 2% basic fuschin dye penetration and measured at ×40 original magnification under the stereomicroscope., Results: The results of this in vitro study showed that coating with G-Coat Plus showed a reduction in microleakage in CGIC and complete absence of microleakage in RMGIC when compared to the noncoated groups, which was statistically significant. CGIC without G-Coat Plus showed highest microleakage followed by RMGIC without G-Coat Plus, followed by a relatively less microleakage in CGIC with G-Coat Plus., Conclusion: Significant reduction in microleakage was seen in conventional GIC and RMGIC with G-Coat Plus when compared to conventional GIC and RMGIC without G-Coat Plus., Competing Interests: None

Objective: The aim of this study was to evaluate the influence of cavity preparation with different Er,Cr:YSGG laser handpieces on microleakage of different posterior composite restorations., Methods: Fifty-four extracted intact human premolars were randomly assigned to three groups according to cavity preparation method: Bur Group: high-speed diamond bur (Diatech), MD Group: Er,Cr:YSGG laser Waterlase MD handpiece (Biolase Millennium II), and Turbo Group: Er,Cr:YSGG laser Waterlase MD TURBO handpiece (Biolase Millennium II). One hundred eight Class II slot cavities were prepared on the mesial and distal proximal surfaces of each tooth, and the cavity preparation times required were determined. The groups were then subdivided according to the restorative systems used (n = 12): a conventional methacrylate-based microhybrid composite (Filtek P60+Adper Single Bond 2/3M); a silorane-based resin composite (Filtek Silorane+Silorane System Adhesive/3M); and a nanohybrid methacrylate-based composite (Kalore+G-Bond/GC). The restorative systems were applied according to the manufacturers' recommendations. Following thermocycling (X5000; 5°C-55°C), the teeth were coated with nail varnish except the restoration margins, immersed in 0.5% basic fuchsin dye solution, and sectioned in a mesiodistal direction. Dye penetration was evaluated under a light microscope for occlusal and cervical margins. Data were analyzed with one-way ANOVA and chi-square tests (p < 0.05)., Results: The cavity preparation time (mean ± SD) required for Bur, MD, and Turbo group was 31.25 ± 3.82, 222.94 ± 15.85, and 92.5 ± 7.42 sec, respectively, and the differences among the groups were statistically significant (p < 0.05). Comparing the occlusal and cervical microleakage scores, no statistically significant differences were found among the groups and subgroups (p > 0.05)., Conclusions: Er;Cr:YSGG laser cavity preparation with the Turbo handpiece needed shorter time than the MD handpiece, although it needed longer time than the conventional diamond bur. The use of different handpieces of Er,Cr:YSGG laser did not differ from conventional preparation with diamond bur in terms of microleakage with the tested methacrylate- and silorane-based posterior composite restorative systems.

Aim: Apical leakage is one of the drawbacks leading to endodontic failure. Various root canal sealants have been tried in endodontics. The present study was conducted to compare root canal sealants such as Endorez, Realseal, and Metaseal in preventing apical leakage., Materials and Methods: Sixty mandibular single-canal premolars were divided into three groups of 20 each. Group I teeth were sealed with Endorez, group II teeth with Realseal, and group III teeth with Metaseal. After completing endodontic treatment in all teeth and sealing with above sealants, glucose leakage value was assessed at 1st, 8th, and 15th day., Results: At day 1 [mean ± standard deviation (SD)], leakage was 0.416 ± 0.011 in group I, 0.234 ± 0.09 in group II, and 0.328 ± 0.19 in group III. On 8th day, it was 2.124 ± 0.108 in group I, 0.624 ± 0.102 in group II, and 1.31 ± 0.24 in group III. On 15th day, it was 5.178 ± 0.125 in group I, 3.122 ± 0.150 in group II, and 4.25 ± 0.28 in group III. The mean apical leakage in all groups in different days was statistically significant (p < 0.05)., Conclusion: Endorez sealant showed highest apical leakage, whereas Realseal had minimum leakage. There was significant increase in leakage in all groups with the progression of time., Clinical Significance: With the advent of different root canal sealants, the success rate of the root canal-treated teeth can be confirmed.

Aim: This article aims to systematically review the evidence reporting on physical properties of bonded amalgam, its clinical performance, and implications., Materials and Methods: An electronic search in "Medline" (search term: Amalgam and Dentin bonding) from 1987 to 2013 yielded 465 publications out of which 170 articles were selected for the analysis. Data were extracted relating to the bond strength of amalgam to dentin, microleakage, postoperative sensitivity, and longevity of bonded amalgam restorations., Results: A total of 129 in vitro studies out of 170 articles showed high bond strengths with filled adhesive resins and light-cured adhesives, in particular Amalgambond plus and Optibond adhe-sives. Thickness of bonding agent, type of alloy, and thermo-cycling showed inconclusive outcomes between bonded and nonbonded amalgam restorations. Majority of studies reported reduced microleakage when dentin bonding agents and resin-modified glass ionomer cements (RM-GICs) were used with amalgam. However, water stored, thermocycled, and spherical amalgam alloys resulted in higher microleakage. While bonded amalgam facilitated the retention of large restorations, reduction in postoperative sensitivity was not consistently observed between bonded and nonbonded amalgam restorations., Conclusion: While bonded amalgam restorations reduce the need for mechanical retention conserving tooth structure and reducing the adverse effects of microleakage, there is lack of consistent evidence across all outcome domains to advocate the benefit of bonding of all amalgam restorations. Despite this, it can be considered the material of choice for large restorations and bonding enhances retention in vitro which can be considered beneficial clinically., Clinical Significance: The use of adhesives to bond amalgam to the tooth structure offers potential advantages, as it helps in conservative cavity preparation without compromising the retention to tooth, making it a material of choice in large posterior restorations.

Objective: This study aimed to assess the coronal-sealing ability of two different root canal obturation materials: gutta-percha with AH Plus and Resilon with Epiphany SE between radiated and nonirradiated groups., Materials and Methods: Fifty-six extracted premolar teeth were randomly divided into two main groups according to the presence or absence of radiotherapy. Specimens were divided into two equal groups. In the radiotherapy group, a total dose of 60 Gy was delivered with 1.8 Gy/d fractions, 5 days a week, for 35 days. The root canals were obturated with either gutta-percha/AH Plus or Resilon/Epiphany SE canal sealer. The samples were then evaluated for the coronal-sealing ability using a centrifuging dye penetration test at 3000 rpm for 5 min in a 2% Rhodamine B solution. The degree of dye penetration was evaluated with a stereomicroscope., Results: Although the sealing ability of both groups was not affected in radiotherapy, the coronal leakage values of Resilon/Epiphany SE slightly increased when radiation was applied (P > 0.05)., Conclusion: Radiotherapy does not significantly affect the coronal-sealing ability of root canal obturation materials, gutta-percha/AH Plus and Resilon/Epiphany SE., Competing Interests: There are no conflicts of interest

Aim: This study aimed to assess cuspal deflection and micro-leakage of mesio-occluso-distal (MOD) cavities in premolar teeth restored with three different tooth-colored restorative materials to determine the effect of polymerization shrinkage stress over time., Materials and Methods: The MOD cavities (4 mm depth) were prepared in 30 sound human maxillary premolars. The teeth were randomly divided into three groups (n = 10). The teeth were then restored with Filtek P60 (group I), X-tra fil (group II), and Admira Fusion x-tra (group III). Cuspal deflection was assessed after 5 minutes, 24 hours, 48 hours, and 7 days by measuring the intercuspal distance. After restoring the teeth, they were subjected to 1,000 thermal cycles and were then immersed in 2% methylene blue for 24 hours. After vertical section of teeth, they were observed under a stereomicroscope to assess micro-leakage. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's honest significant difference (HSD) post hoc test. Friedman test was used to compare different time points in each group and nonparametric Mann-Whitney test was applied to assess microleakage (a < 0.05)., Results: The mean cuspal deflection was significantly different in the three groups (p < 0.001). The highest deflection was noted in Filtek P60 (14.8 ± 1.9) and the lowest was noted in Admira Fusion x-tra (7.4 ± 1.4 μm). Cuspal deflection significantly decreased after 7 days, but did not return to the baseline value. Admira Fusion x-tra showed significantly less deflection after 7 days (p < 0.001), but the other two groups were the same (p = 0.3). Microleakage was not significantly different among the three groups (p > 0.05)., Conclusion: The lowest cuspal deflection was noted in Admira Fusion x-tra, although marginal microleakage was not significantly different among the groups., Clinical Significance: As the lowest cusp deflection was noted in Admira Fusion x-tra, this restorative material can be suitable for esthetic restoration of extensive posterior cavities.

Objective: To evaluate the effect of load-cycle aging and/or 6 months artificial saliva (AS) storage on bond durability and interfacial ultramorphology of resin-modified glass ionomer cement (RMGIC) applied onto dentine air-abraded using Bioglass 45S5 (BAG) with/without polyacrylic acid (PAA) conditioning., Methods: RMGIC (Ionolux, VOCO) was applied onto human dentine specimens prepared with silicon-carbide abrasive paper or air-abraded with BAG with or without the use of PAA conditioning. Half of bonded-teeth were submitted to load cycling (150,000 cycles) and half immersed in deionised water for 24 h. They were cut into matchsticks and submitted immediately to microtensile bond strength (μTBS) testing or 6 months in AS immersion and subsequently μTBS tested. Results were analysed statistically by two-way ANOVA and Student-Newman-Keuls test (α = 0.05). Fractographic analysis was performed using FE-SEM, while further RMGIC-bonded specimens were surveyed for interfacial ultramorphology characterisation (dye-assisted nanoleakage) using confocal microscopy., Results: RMGIC applied onto dentine air-abraded with BAG regardless PAA showed no significant μTBS reduction after 6 months of AS storage and/or load cycling (p > 0.05). RMGIC-dentine interface showed no sign of degradation/nanoleakage after both aging regimens. Conversely, interfaces created in PAA-conditioned SiC-abraded specimens showed significant reduction in μTBS (p < 0.05) after 6 months of storage and/or load cycling with evident porosities within bonding interface., Conclusions: Dentine pre-treatment using BAG air-abrasion might be a suitable strategy to enhance the bonding performance and durability of RMGIC applied to dentine. The use of PAA conditioner in smear layer-covered dentine may increase the risk of degradation at the bonding interface., Clinical Significance: A combined dentine pre-treatment using bioglass followed by PAA may increase the bond strength and maintain it stable over time. Conversely, the use of PAA conditioning alone may offer no significant contribute to the immediate and prolonged bonding performance., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Purpose: The aim of this study was to evaluate the microgap between the abutment and implant as well as the circularity of implant platforms and associating conformational errors with bacterial microleakage in tapered connection implant systems., Materials and Methods: Four brands of implants with a tapered abutment connection were tested. Bacterial leakage was assessed using 0.3 μL of Escherichia coli suspension inoculated into the abutment screw chamber of the implants, which were then torqued and incubated at 37°C for 14 days. All specimens used for the microbiologic experiment were then cut lengthwise, and the microgap was measured at three points on each side of the sample using scanning electron microscopy (up to 5,000× magnification). Microtomography was used to assess implant platform circularity to validate the microscopic findings qualitatively., Results: Two samples from the Nobel Biocare system, four from the Ankylos (Dentsply) system, four from the Neodent (Straumann) system, and five from the Conexão system were positive for bacterial leakage, with no significant difference between groups. The Neodent system had the highest mean microgap values (5.84 ± 9.83 μm), followed by the Nobel Biocare systems (5.17 ± 4.10 μm), Ankylos (3.47 ± 3.28 μm), and Conexão (2.72 ± 3.19 μm), with no significant difference between systems. All systems showed conformational errors of circularity on microtomography images., Conclusion: The tapered connection systems evaluated herein were not able to halt bacterial leakage, nor were they free from conformational errors.

Objective: To compare apical microleakage of extracted, single-rooted teeth obturated with thermoplasticized injectable gutta-percha using two different endodontic sealers (calcium-hydroxide and resin based)., Study Design: An experimental study., Place and Duration of Study: The Aga Khan University Hospital (AKUH), Dental Clinics and Laboratory from June to September 2015., Methodology: The study was conducted using extracted teeth. After access cavities were made, cleaning and shaping of root canals was done in 70 teeth. Teeth were randomly allocated into two groups and obturated with thermoplasticized injectable gutta-percha (Obtura II) using two sealers (Sealapex vs. AH plus). After immersing the teeth in 2.0% methylene blue, they were split longitudinally, viewed under light microscope (magnification X4) and images were taken by a camera connected to microscope. The extent of dye penetration was assessed from apex to its coronal part and recorded in millimeters. Independent sample t-test was used to compare microleakage in the two groups. Pearson correlation coefficient was used for inter-examiner reliability of dye penetration measurements. A p-value of <0.05 was taken as statistically significant., Results: Teeth obturated with Obtura II gutta-percha with AH plus sealer had a mean dye penetration of 1.20 ±0.79 mm. This was significantly better than Obtura II with Sealapex sealer (p=0.003)., Conclusion: Obtura II-AH plus sealer was a better combination for obturation as it showed a lesser degree of microleakage. Obtura II with Sealapex group showed higher microleakage, so this combination should be avoided in single-rooted teeth.

This study evaluated the effect of fiber inserts combined with composite resins on enamel and dentin margin microleakage. The fiber inserts were used with high- (x-tra fil) and low-viscosity (x-tra base) bulk-fill composite resins and as well as conventional composite resins (Grandio and Grandio Flow). In 96 sound, recently extracted molars, 2 standardized Class II cavities were prepared. The teeth were randomly divided into 8 groups of 12 teeth each, based on composite resin type and presence or absence of fiber inserts: groups 1 and 2, x-tra fil with and without fiber inserts, respectively; groups 3 and 4, x-tra base with and without fiber inserts; groups 5 and 6, Grandio with and without fiber inserts; and groups 7 and 8, Grandio Flow liner (gingival floor)/Grandio (remainder of cavity) with and without fiber inserts. In all the groups, a 2-step etch-and-rinse adhesive was used. The specimens were processed in a dye penetration technique to determine microleakage percentages. Data were analyzed with analysis of variance, Tukey, and t tests. There was significantly less leakage at the enamel margins than the dentin margins. Fiber reinforcement significantly decreased enamel microleakage in all the groups, with no significant differences among the groups. Concerning dentin microleakage, there were no significant differences among the 4 groups without fiber inserts, while a significant difference was detected in groups 2 (x-tra fil plus fiber) and 8 (Grandio Flow plus fiber/Grandio). Fibers significantly improved dentin sealing in groups 2 and 8. These findings suggest that a fiber insert reinforcing bulk-fill and conventional composite resins might improve enamel sealing in shallow Class II cavi-ties. The effect of fiber reinforcement on the dentin margins of deep cavities depended on the viscosity of the composite resins; fiber reinforcement was effective for flowable bulk-fill and conventional composite resin restorations., Competing Interests: Disclaimer: The authors report no conflicts of interest pertaining to the products or companies discussed in this article.

Aim: The purpose of the study is to evaluate the bacterial micro-leakage of three different materials, mineral trioxide aggregate (MTA), resin-modified glass ionomer cement (RMGIC), and flowable composite, as a coronal barrier against Enterococcus faecalis., Materials and Methods: A total of 100 human extracted single-rooted teeth were selected. Access opening done, working length determined, and canals were cleaned and shaped with ProTaper F3 and obturated with AH26 and gutta-percha (GP) using lateral condensation technique. Samples were divided into three experimental and two control groups. Approximately 3 mm GP was removed from the coronal orifice and restored with one of the test materials. Teeth were suspended in glass tubes containing brain heart infusion (BHI) broth and equipped with microcaps, which were used to check bacterial leakage. A 24-hour broth of E. faecalis was placed in the pulp chamber. Tubes were incubated and checked for turbidity for 90 days. Data were analyzed using chi-squared test between the test and control groups and Fisher test between the test groups., Results: Significantly lesser number of samples turned turbid in the RMGIC group followed by MTA group and the maximum number of samples turned turbid in the flowable composite group., Conclusion: The RMGIC is a better coronal sealer, followed by MTA and flowable composite., Clinical Significance: Coronal sealing ability of RMGIC is more promising in comparison with the other agents.

Objectives: Smear layer deproteinizing was proved to reduce the organic phase of smear layer covered on dentin surface. It was shown to eliminate hybridized smear layer and nanoleakage expression in resin-dentin bonding interface of two-step self-etch adhesive. This study aimed to investigate those effects on various one-step self-etch adhesives., Methods: Four different one-step self-etch adhesives were used in this study; SE One (SE), Scotchbond™ Universal (SU), BeautiBond Multi (BB), and Bond Force (BF). Flat human dentin surfaces with standardized smear layer were prepared. Smear layer deproteinizing was carried out by the application of 50ppm hypochlorous acid (HOCl) on dentin surface for 15s followed by Accel ® (p-toluenesulfinic acid salt) for 5s prior to adhesive application. No surface pretreatment was used as control. Microtensile bond strength (μTBS) and nanoleakage under TEM observation were investigated. The data were analyzed by two-way ANOVA and Tukey's post-hoc test and t-test at the significant level of 0.05., Results: Smear layer deproteinizing significantly improved μTBS of SE, SU, and BB (p<0.001). Hybridized smear layer observed in control groups of SE, BB, and BF, and reticular nanoleakage presented throughout the hybridized complex in control groups of BB and BF were eliminated upon the smear layer deproteinizing., Significance: Smear layer deproteinizing by HOCl and Accel ® application could enhance the quality of dentin for bonding to one-step self-etch adhesives, resulting in the improving μTBS, eliminating hybridized smear layer and preventing reticular nanoleakage formation in resin-dentin bonding interface., (Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Objectives: A lack of appropriate adhesiveness is one of the biggest problems in restorative dentistry today and the main cause of microleakage. This is especially true in pediatric dentistry where moisture control is more difficult to achieve. Glass ionomer restorative materials increase adhesion and decrease microleakage given their chemical adhesion to the remaining tooth substance. Pretreatment improves the adhesion quality. The aim of this study was to assess the microleakage of Glass ionomer restorative materials following application of 20% polyacrylic acid, 10% polyacrylic acid or 2% chlorhexidine digluconate in Class V cavities., Study Design: Two Class V preparations were prepared on the buccal and lingual surfaces of 24 extracted human molars. The gingival wall was set below or above the CEJ. The teeth were divided into 2 groups. Group 1 was treated with 20% polyacrylic acid or 10% polyacrylic acid. Group 2 was treated with 10% polyacrylic acid or 2% chlorhexidine digluconate. Microleakage was evaluated using a light-reflecting stereomicroscope and stain penetration test., Results: Two percent chlorhexidine digluconate was as efficient as the other conditioners. No statistically significant differences were found among the three types of conditioners. Dye penetration was significantly greater into dentin than into enamel among all three conditioners in both groups (P<0.001)., Conclusion: Two percent chlorhexidine digluconate, with its known added advantages, can be used as a pretreatment conditioner in GI restorations.

Aim: Fissure sealants are effective in preventing caries. The aim of this in vitro study was to evaluate the effects of two different enamel surface preparation techniques for pit and fissure sealing., Materials and Methods: Sixty extracted sound third molars were used. For each tooth, the mesial half of the occlusal fissures was treated with ultrasound diamond tip T1 mounted on an ultrasonic handpiece, while the distal half with conventional diamond bur. The teeth were randomly divided into 2 groups (n = 30/each). Group 1 samples were stored in distilled water at 4 °C. For group 2 samples, sealing of occlusal fissures was performed according to standard procedures. Bucco-lingual cuts parallel to the long axis of the tooth were made in order to separate the two different types of preparations. The effects of the executed procedures were assessed with SEM., Results: Surfaces prepared with ultrasound system showed the presence of residual debris and appeared more irregular than surfaces prepared with traditional bur system. Furthermore, images showed the presence of cracks on the bottom and on the walls of the ultrasound prepared fissures., Conclusion: Conventional bur surface treatment showed a better performance when compared to ultrasound preparation and could probably ensure superior sealant retention.