Search

Objectives Restoration of primary teeth have become more critical than extracting them. Composite resin materials are considered suitable materials for primary teeth restoration due to their aesthetic and acceptable performance. However, they have limitations such as polymerization shrinkage, microleakage, post-treatment sensitivity, and reduced marginal adaptation. This study evaluated the microleakage of Tokuyama Bulk flow composite and Grandiflow composite resin materials in restored primary teeth. Methods In this in vitro study, 54 primary teeth were randomly divided into two groups. After preparing the Class II cavity in the samples and applying acid etch and bonding material, one group was allocated to the Tokuyama Bulk flow composite, and the other group was allocated to the Grandiflow composite. The amount of microleakage was determined by immersion of samples in 1% methylene blue dye and evaluation under stereomicroscope. Scores from 0 to 3 were assigned depending on the degree of dye penetration. Mann-Whitney U test was used to compare the scores in two groups at a significance level of 0.05. Results The amount of microleakage in the Grandiflow group was significantly higher than the Tokuyama Bulk flow group (p=0.019). In the Grandiflow group, the highest microleakage score was 3 (63.0%), 2 (29.6%), and 1 (7.4%), respectively. In the Tokuyama Bulk flow group, the highest microleakage scores were 2 (55.6%), 3 (29.6%), 1 (11.1%), and 0 (3.7%), respectively. Conclusion It can be concluded that Tokuyama Bulk flow composites have lower microleakage than the Grandiflow composite, potentially affecting the microleakage and subsequent failure of the restoration in a positive way. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencias de la Salud is the property of Colegio Mayor de Nuestra Senora del Rosario and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

INTRODUCTION: Low marginal adaptation and therefore micro-leakage, is one of the weaknesses of bulk fill resin composites. Pre-heating of composite resins reduces their viscosity, thus, increasing the marginal adaptation and decreasing their micro-leakage. OBJECTIVES: The aim of this study was to examine the effect of pre-heating on micro-leakage of bulk fill composite resins in dentin margins of class II restorations. MATERIAL AND METHODS: This in-vitro study was conducted on 39 extracted human molars. Class II cavities were prepared on teeth's proximal surfaces. Teeth were divided randomly into three groups, which were restored using three different composites: Group 1 -- X-tra fil composite; Group 2 -- Opus Bulk Fill composite; and Group 3 -- Gradia Posterior composite. Each group included 2 sub-groups: at room temperature and after one pre-heating cycle at 50°C. The teeth were placed in fuchsin solution for 24 hours and were examined for micro-leakage under a stereoscopic microscope. Mann-Whitney U and Kruskal-Wallis tests were applied with SPSS 16 software. P-value of less than 0.05 was considered significant. RESULTS: Pre-heating reduced micro-leakage significantly (p < 0.001). There was no significant difference in micro-leakage of different composites (p < 0.05). CONCLUSIONS: Pre-heating to 50°C decreases micro-leakage in the dentin margin of class II restorations in bulk fill composites (X-tra fil and Opus Bulk Fill) and conventional composite (Gradia Posterior). Investigating the effect of various pre-heating procedures, such as different temperatures, duration, and repeated pre-heating on physical and mechanical features of bulk fill materials, is suggested for future studies. [ABSTRACT FROM AUTHOR]

Amaç: Bu in vitro çalışmanın amacı, universal adeziv sistemin farklı uygulama yöntemlerinin sınıf V akışkan kompozit restosyonların kenar mikrosızıntısı üzerine etkilerinin değerlendirilmesidir. Gereç ve Yöntem: Bu çalışmada, toplam 60 adet sağlam premolar diş kullanıldı. Dişlerin bukkal yüzeylerine, servikal kenarı dentinde ve okluzal kenarı minede olacak şekilde standardize edilmiş Sınıf V kaviteler (3 mm x 3 mm x 1.5 mm) hazırlandı. Örnekler, kompozit rezin tipi (Filtek Z250/FZ, Metafil Bulk Fill/MB ve Nova Compo HF/NC) ve universal adezivin uygulama yöntemlerine göre (selektif etch/SEE ve self-etch/SE) rastgele 6 gruba ayrıldı: Grup FZ+SEE, Grup FZ+SE, Grup MB+SEE, Grup MB+SE, Grup NC+SEE, Grup NC+SE. Örnekler, 24 saat 37° C’de distile su içerisinde bekletildi ve 10.000 döngüde termal siklusa tabi tutuldu. Ardından, %0.5 metilen mavisi solüsyonunda 24 saat süresince bekletildi. Mikrosızıntı tespiti için, stereomikroskop altında (40x büyütme) incelendi. Verilerin istatistiksel analizinde, Kruskal Wallis ve Mann-Whitney U testleri kullanıldı (p0.05). Grup NC+SE hariç, diğer tüm gruplarda servikal kenarda okluzal kenara göre istatistiksel olarak daha fazla mikrosızıntı değeri gözlendi (p

Background. When bleaching agents contact dental structures, they act on restorative materials and adhesive interfaces. This study investigated the effect of "at-home" and "in-office" bleaching on the microleakage of composite resin restorations performed with different universal adhesives in self-etch and etch-and-rinse modes. Methods. Class V cavities were prepared in 132 premolars. The samples were divided into four groups (n=33). All Bond Universal adhesive was used in the first and second groups, and G-Premio Bond adhesive was used in the third and fourth groups. The total-etch mode was used in the first and third groups, and the self-etch mode was used in the second and fourth groups. The samples were divided into three subgroups (n=11). In the first subgroup, home bleaching was used, and in the second subgroup, office bleaching was used. In the third subgroup, bleaching was not performed. The specimens were examined under a stereomicroscope for microleakage. Ordinal regression analysis was applied (P0.05). Conclusion. Based on the results of the microleakage test, bleaching after composite resin restorations did not significantly affect the microleakage of Class V restorations.

Background: Coronal seal is one of the essential factors that affects the success of endodontic treatment and reinforces the apical seal. The intra-orifice barrier is an efficient alternative approach to decrease coronal leakage in endodontically treated teeth and various materials have been used for this purpose. This study aimed to compare the coronal sealing of flowable composite, resin-modified glass ionomer (RMGI), and mineral trioxide aggregate (MTA) in endodontically treated teeth. Materials and Methods: In this in vitro study, 35 single-canal canine teeth were divided into five groups, including flowable composite, RMGI, MTA, positive control, and negative control groups. The teeth were filled with restorative materials according to the factory's instructions. Afterward, the samples were immersed in 2% methylene blue dye solution for 1 week at 37°C and 100% humidity condition. Finally, the teeth were sectioned longitudinally and dye penetration was measured using a stereomicroscope with x10. Data were analyzed with Kolmogorov-Smirnov and Kruskal-Wallis tests (α= 0.05). Results: The positive control group showed the highest amount of dye penetration compared to other groups (12.34 ± 0.46). Dye penetration in the MTA group was significantly lower (4.25 ± 0.31) compared to the RMGI group (5.94 ± 0.24) (P = 0.02). Moreover, while the dye penetration in the MTA group was lower than in the flowable composite group (5.65 ± 0.26), the difference was not statistically significant (P = 0.12). Conclusion: MTA reduces the coronal leakage and provides an acceptable coronal seal in endodontically treated teeth, especially compared to RMGI, and therefore, using MTA as an intra-orifice barrier increases the endodontic treatment success rate. [ABSTRACT FROM AUTHOR]

Copyright of Acta Odontologica Turcica is the property of Acta Odontologica Turcica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: The ability of the temporary filling to seal endodontic access cavities may be crucial for the success of endodontic treatment. Numerous in vitro studies have investigated the sealability of the temporary fillings used in endodontic treatments. However, in vitro sealability studies have been criticized for their inconsistent results and questionable clinical relevance. Some journals have imposed moratoriums on publishing such studies to encourage researchers to test their validity and clinical relevance. Since the implementation of this moratorium, little progress has been made in this field. To further encourage researchers to investigate the reliability of these studies, this review presents an overview of the methodologies of studies that examine the ability of temporary filling materials to seal the endodontic access cavity in vitro and discusses the criticisms of these studies in detail. Materials and Methods: PubMed, Scopus, and Embase electronic databases were searched to identify studies that tested in vitro the ability of temporary filling materials to seal endodontic access cavities. Only original articles published in English between 01/01/1970 and 28/02/2022 were included. Results: The search yielded 551 results. After removing duplicates and excluding studies that did not meet the inclusion criteria, 94 studies were included in this review. Conclusion: Although clinical studies may be the best way to test the performance of temporary fillings, the ethical importance of conducting preliminary in vitro studies is undeniable. It seems that questioning the reliability of in vitro sealability studies is not based on sufficient scientific evidence and that the inconsistencies in the results of these studies may be due to differences in the methodological and clinically relevant variables between them, rather than due to their unreliability.

Abstract Objectives This study assessed the enamel and dentin margin microleakage of class II cavities of primary molars restored with a bulk‐fill and a conventional composite. Materials and Methods In this in vitro, experimental study, standard class II cavities were created in the proximal surfaces of 60 extracted primary molars. The teeth were randomly divided into two groups, and restored with SonicFill bulk‐fill and Filtek Z250 conventional composite along with Single Bond 2 adhesive. The teeth were coated with two layers of nail varnish to 1 mm around the restoration margins, and the apices were sealed with wax. The teeth underwent 1500 thermal cycles and incubated at 37°C for 24 h. They were then immersed in 1 M silver nitrate in the dark, rinsed with water, immersed in developing solution for 12 h, and exposed to fluorescent light. Next, they were mesiodistally sectioned, and digitally photographed under a stereomicroscope at ×10 magnification. The dye penetration depth was measured by a blind observer, and analyzed by the Mann–Whitney U test (α = .05). Results No significant difference existed in microleakage between the two composite groups at the enamel (p = .76) or dentin (p = .16) margins. In both composite groups, microleakage at the dentin margins was significantly greater than that at the enamel margins (p = .000). Conclusion Considering the absence of a significant difference in microleakage, SonicFill bulk‐fill composite can be used as an alternative to Filtek Z250 conventional composite for restoration of primary molars to benefit from its advantages such as simpler and faster application.

The aim of this study was to determine whether erbium laser irradiation emitted by modified glass-fiber tips would improve the intraradicular bonding of fiber posts. Forty human canines were endodontically treated and prepared for fiber-post placement. Roots were divided into five groups (n=8); according to the laser-tip combinations (2,940 nm Er:YAG and 2,780 nm Er,Cr:YSGG). Nonirradiated root canals served as control. Posts were cemented with self-adhesive resin cement and subjected to push-out test. Failure modes were characterized, and intraradicular bonded interfaces were analyzed by SEM and submitted to nanoleakage evaluation. Data were analyzed by two-way ANOVA and Tukey test (a=0.05). No significant differences were observed in cervical and middle sections (p>0.05), while significantly higher bond strengths were observed in apical sections (p<0.05). Laser irradiation reduced adhesive failures, cement-dentin gap formation, and nanoleakage apically. Laser-irradiation protocols employing end- or radial-firing tips improved bonding to apical intraradicular dentin contributing to more uniform bonded interfaces. [ABSTRACT FROM AUTHOR]

The ability of the temporary filling to seal endodontic access cavities may be crucial for the success of endodontic treatment. Numerous in vitro studies have investigated the sealability of the temporary fillings used in endodontic treatments. However, in vitro sealability studies have been criticized for their inconsistent results and questionable clinical relevance. Some journals have imposed moratoriums on publishing such studies to encourage researchers to test their validity and clinical relevance. Since the implementation of this moratorium, little progress has been made in this field. To further encourage researchers to investigate the reliability of these studies, this review presents an overview of the methodologies of studies that examine the ability of temporary filling materials to seal the endodontic access cavity in vitro and discusses the criticisms of these studies in detail. PubMed, Scopus, and Embase electronic databases were searched to identify studies that tested in vitro the ability of temporary filling materials to seal endodontic access cavities. Only original articles published in English between 01/01/1970 and 28/02/2022 were included. The search yielded 551 results. After removing duplicates and excluding studies that did not meet the inclusion criteria, 94 studies were included in this review. Although clinical studies may be the best way to test the performance of temporary fillings, the ethical importance of conducting preliminary in vitro studies is undeniable. It seems that questioning the reliability of in vitro sealability studies is not based on sufficient scientific evidence and that the inconsistencies in the results of these studies may be due to differences in the methodological and clinically relevant variables between them, rather than due to their unreliability. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to compare the microleakage of an adhesive fissure sealant (AFS), a flowable composite resin (FC), and a resin-modified glass ionomer (RMGI) in permanent teeth. Methods: This in vitro, experimental study was conducted on 45 extracted posterior teeth with sound fissures. The teeth were randomly divided into 3 groups (n=15). The occlusal fissures were sealed with Beautisealant AFS without etching and bonding in group 1, with Beautifil FC after 37% phosphoric acid etching in group 2, and with Fuji II LC RMGI in group 3. The teeth underwent 500 thermal cycles (5-55°C), and their apices were sealed with wax. They were then immersed in 2% methylene blue for 24 hours. Next, the teeth were sectioned buccolingually and inspected under a stereomicroscope to measure the dye penetration depth as an indicator of microleakage. Data were analyzed by ANOVA, Chi-square test, and Scheffe test (alpha=0.05). The study was approved by the ethics committee of Hamadan University of Medical Sciences (IR.UMSHA.REC.1399.728). Results: The microleakage score of RMGI was significantly higher than that of AFS and FC (P<0.05), while the microleakage scores of FC and AFS were not significantly different (P=0.330). Conclusions: The AFS showed a sealing ability comparable to that of FC, and can be used as an alternative to FC due to its fewer application steps. [ABSTRACT FROM AUTHOR]

Background.: When bleaching agents contact dental structures, they act on restorative materials and adhesive interfaces. This study investigated the effect of "at-home" and "in-office" bleaching on the microleakage of composite resin restorations performed with different universal adhesives in self-etch and etch-and-rinse modes. Methods.: Class V cavities were prepared in 132 premolars. The samples were divided into four groups (n=33). All Bond Universal adhesive was used in the first and second groups, and G-Premio Bond adhesive was used in the third and fourth groups. The total-etch mode was used in the first and third groups, and the self-etch mode was used in the second and fourth groups. The samples were divided into three subgroups (n=11). In the first subgroup, home bleaching was used, and in the second subgroup, office bleaching was used. In the third subgroup, bleaching was not performed. The specimens were examined under a stereomicroscope for microleakage. Ordinal regression analysis was applied (P <0.05).> Results.: The adhesive type, application method, and margin type significantly affected microleakage (P <0.05).>P>0.05). Conclusion.: Based on the results of the microleakage test, bleaching after composite resin restorations did not significantly affect the microleakage of Class V restorations. [ABSTRACT FROM AUTHOR]

Introduction : Due to concerns about histological caries and recurrent caries after the use of sealants, adhesive systems containing fluoride and antibacterial agents have been proposed. The aim of this study was to evaluate the microleakage of sealants after the use of antibacterial chlorhexidine solution on etched enamel with and without the use of fifth - and sixth -generation adhesive systems . Materials & Methods: In this experimental study, sixty sound human premolars were divided into 4 groups as follows: Group A: Etching, fissure sealant; Group B: Etching, chlorhexidine solution (2 %), fissure sealant; Group C: Etching, chlorhexidine solution, single bond, fissure sealant; Group D: Etching, chlorhexidine solution, Clearfil SE Bond, fissure sealant. The samples were thermocycled for 500 cycles and immersed in basic fuchsine 0.5%. Then, the teeth were embedded in acrylic resin and cut buccolingually parallel to the long axis. Microleakage of the specimens was observed under ×40 magnification and graded from 0 to 3. Data were analysed using the Kruskal -Wallis and Mann -Whitney U tests. A value of p<0.05 was considered significant. Results: Sealant micro -leakage was statistically lower in group A (etching, fissure sealant) than in groups B, C and D, the groups with the chlorhexidine solution (P < 0.05). There was no statistically significant difference between groups B, C and D. Conclusion: The use of chlorhexidine solution on the etched enamel increases the sealant microleakage; with and without the application of the adhesive systems, Single Bond or Clearfil SE Bond. Therefore, it cannot be used as one of the steps in the application of the sealant to reduce the colonization of bacteria around the fissure sealant. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of pre-cured and co-cured flowable composite liner on fracture strength and microleakage of primary anterior teeth with extended composite resin restorations. Methods: In the current in vitro experimental study, the crowns of 54 extracted primary canine teeth were cut 1 mm above the CEJ, and a pulpectomy procedure was performed. The samples were randomly divided into three groups to restore the coronal part up to 4 mm above the CEJ. In group 1, the samples were built up with Filtek Z250 packable composite resin. In group 2 (pre-cure), first, 1 mm of Filtek Z350 XT flowable liner was applied to the sample, and after curing, the restoration process continued using packable composite resin. In group 3 (co-cure), the flowable composite liner was cured while the first layer of packable composite resin was applied; then, the same restorative procedure similar to the other groups was followed. The samples' cross-sectional area in the fracture strength test was calculated by AutoCAD software. Subsequently, the samples were subjected to a force in a universal testing machine. The samples related to the microleakage experiment were cut vertically, and then, the dye penetration percentage (10% methylene blue) was measured under a stereomicroscope. ANOVA was used to analyze the data. Results: Mean fracture strength in group 2 was significantly higher than in group 1 (P = 0.016). The microleakage mean in group 3 was significantly lower than in groups 1 (P = 0.000) and 2 (P = 0.026). Conclusion: The flowable composite liner and its relevant separate curing increased the fracture strength of composite resin restorations. However, less microleakage was reported in the group where the liner was applied as a co-cure. [ABSTRACT FROM AUTHOR]

Background & Aim: Microleakage is one of the most common problems in bonding systems. The ingress of micro-organisms and oral fluids through microscopic spaces between restoration and tooth structure is known as microleakage. The aim of this research was to compare the Microleakage of three types of bondings in CLV composite cavities. Material and Methods: In this experimental study, CLV cavities were prepared in 2*3*2 mm on the buccal surfaces of 45 premolars, with the occlusal margin on enamel and gingival margin on cementum 1 mm below CEJ. The teeth were divided into 3 groups of 15 each. The cavities were treated by Futurabond DC, Solo Bond M, and Futurabond NR (Voco, Germany). Grandio composite (Voco, Germany) was used to restore the cavities. After thermocycling, the samples were immersed in silver nitrate for 24 h and then in developer solution for 6 h. samples evaluated under a stereomicroscope after buccolingual sectioning. Kruskal Wallis test was used for statistical analysis. Results: This study revealed that in the gingival area, Solo Bond M had type 1 microleakage in 80% of the cases (dye penetration up to 1/3 of the cavity wall) and type 2 microleakage in 20% (dye penetration up to 2/3 of the cavity wall). Futurabond DC bond had no microleakage in 6.7% of the cases, type 1 in 66.7%, and type 2 in 26.7% of the cases. Futurabond NR bonding had no microleakage in 6.7%, type 1 in 33.3%, and type 3 in 60% of cases (dye penetration in all cavity walls without axial wall involvement ). There was no statistically significant difference in the microleakage at the occlusal margins between 3 groups (P=0/071) Conclusion: the amount of microleakage in the occlusal area of the cavity is not significantly different in any of the 3 groups, but The amount of microleakage in the gingival area has a significant difference so that the amount of microleakage of Futurabond NR is significantly higher than the two groups of Futurabond DC and Solo Bond M. [ABSTRACT FROM AUTHOR]

Objectives: This study assessed the enamel and dentin margin microleakage of class II cavities of primary molars restored with a bulk‐fill and a conventional composite. Materials and Methods: In this in vitro, experimental study, standard class II cavities were created in the proximal surfaces of 60 extracted primary molars. The teeth were randomly divided into two groups, and restored with SonicFill bulk‐fill and Filtek Z250 conventional composite along with Single Bond 2 adhesive. The teeth were coated with two layers of nail varnish to 1 mm around the restoration margins, and the apices were sealed with wax. The teeth underwent 1500 thermal cycles and incubated at 37°C for 24 h. They were then immersed in 1 M silver nitrate in the dark, rinsed with water, immersed in developing solution for 12 h, and exposed to fluorescent light. Next, they were mesiodistally sectioned, and digitally photographed under a stereomicroscope at ×10 magnification. The dye penetration depth was measured by a blind observer, and analyzed by the Mann–Whitney U test (α =.05). Results: No significant difference existed in microleakage between the two composite groups at the enamel (p =.76) or dentin (p =.16) margins. In both composite groups, microleakage at the dentin margins was significantly greater than that at the enamel margins (p =.000). Conclusion: Considering the absence of a significant difference in microleakage, SonicFill bulk‐fill composite can be used as an alternative to Filtek Z250 conventional composite for restoration of primary molars to benefit from its advantages such as simpler and faster application. [ABSTRACT FROM AUTHOR]

Background/Aim: The aim of this study was to examine the microleakage values after restoring the prepared Class II box cavities using two different composite resins with three different layering methods and polymerizing them with five different LED light devices. Material and Methods: Class II box cavities were prepared in 150 extracted mandibular molars. Nanoceramic composite resin (Ceram.x SphereTEC one universal A2, Dentsply, Germany) and bulk fill composite resin (SDR flow+ A2, Dentsply, Germany) were used for the restoration of the cavities. Teeth were restored with three different layering methods (bulk fill, horizontal layering, and centripetal buildup technique) and five different LED light devices [(Smartlite Focus, Dentsply, USA), (Led.E, Woodpecker, China), (Valo Cordless, Ultradent, USA), (Bluephase N, Ivoclar Vivadent, Liechtenstein), (D-Light Pro (GC, USA)] and then subjected to microleakage analysis. Kruskal Wallis and Mann Whitney U test were used for statistical analysis. Th e data was evaluated under p

Introduction: Self-adhering flowable composite resins were recently introduced to combine the merits of both adhesive and restorative technologies in one product. This study aimed to evaluate the microleakage of a self-adhering flowable composite in comparison with a conventional flowable composite and resin-modified glass ionomer cement in class V cavities. Methods: In this in vitro experimental study, class V cavities were prepared in the buccal and lingual surfaces of 20 sound human molars (40 cavities). The cavities were randomly divided into 4 groups (n=10) and restored with Vertise Flow self-adhering flowable composite in group A, Premise conventional flowable composite in group B, etched with 37% phosphoric acid and restored with OptiBond Solo Plus + Vertise Flow in group C, and Fuji II LC glass ionomer in group D. The specimens were thermocycled for 1000 cycles (5-55°C), immersed in 0.5% basic fuchsine dye solution for 24 h, sectioned, and observed under a stereomicroscope. Data were analyzed by SPSS software using the Kruskal-Wallis, Npar, and Wilcoxon signed rank tests (alpha=0.05). Results: The Kruskal-Wallis test showed that the degree of microleakage was not significantly different among different groups at the enamel margin (P=161) or the dentin margin (P=467). The Wilcoxon signed rank test revealed that the difference in microleakage between the dentin and enamel margins was significant within all four groups (P

Statement of the Problem: The dilemma of microleakage at the composite-tooth interface is still a major challenge in operative dental practice. Purpose: This study aimed to compare the microleakage of universal adhesive with self-etch and total-etch bonding strategies for restoration of class-II primary molar cavities. Materials and Method: This in vitro, experimental study was conducted on 75 extracted primary molars. Class-II cavities were prepared in mesial or distal surfaces. The teeth were randomly divided into five groups of Adper Single Bond 2 (3M ESPE; St Paul, MN, USA), Clearfil SE Bond (Kuraray Noritake, Osaka, Japan), G-Bond (GC Corp., Tokyo, Japan), G-Premio Bond (GC Corp., Tokyo, Japan) with total-etch mode and G-Premio Bond with self-etch mode. Cavities were also restored with Nano-hybrid resin composite (Grandio, VOCO, Cuxhaven, Germany) and incubated for 24 hours, followed by thermocycling at 1500× between 5-55°C within a dwell time of 20 seconds. Later, the cavities were placed in 1M silver nitrate solution and evaluated under a stereomicroscope. Finally, microleakage was assessed quantitatively and qualitatively. One tooth in each group was prepared and evaluated under a scanning electron microscope (SEM). Data were analyzed using One-way ANOVA, Tukey's post hoc test and Chi-square test (p< 0.05). Results: The microleakage values were significantly different in the study groups (p< 0.05). The highest level of microleakage was noted in G-Bond and the lowest in G-Premio Bond with total etching. There was a significant correlation between the qualitative and quantitative measurements of microleakage. Conclusion: The G-Premio Bond yielded acceptable results in terms of microleakage in total-etch and self-etch modes. However, additional etching is recommended to improve the quality of bonding.

To evaluate the effects of single and double application of immediate dentin sealing (IDS) techniques on marginal leakage and microtensile bond strength of resin cement. Twenty-five extracted third molars were divided into five experimental groups in order to test the marginal leakage and microtensile bond strength (µTBS) of direct bonding, single and double application of IDS techniques using three-step etch-and-rinse (1TE&2TE), and universal (1U&2U) adhesive systems. For the single application of the IDS technique, dental adhesive was applied on the prepared dentin prior to temporary cementation. For the double application, dental adhesive was re-applied after polymerization of the first layer and before temporary cementation. After removing the temporary cementation, the dentin surface was cleaned with an excavator and pumice slurry. Resin cement was used to bond a composite rod to the dentin surface. All specimens were cyclic loaded (50N, 2Hz, 50,000 cycles) and immersed in marginal leakage solutions, and then sectioned into two parts. The first half was cut into small square beams for µTBS testing, while the other half was examined under a light microscope for marginal leakage. The 1TE and 1U groups provided significantly higher µTBS (23.56±3.26 MPa, 21.51±1.30 MPa) than the direct bonding technique (13.56±2.74 MPa) (p < 0.001). There was significant reduction of µTBS (2TE = 21.41±1.59 MPa, 2U = 17.51±2.80 MPa) (p < 0.01) after applying the second layer of adhesive. The marginal leakage was not significantly different in all groups. The two-layer IDS technique using either three-step etch-and-rinse or self-etch universal adhesive did not show any advantage in the µTBS testing or marginal leakage over the one-layer IDS techniques, which showed significantly greater µTBS than the direct bonding technique. [ABSTRACT FROM AUTHOR]

Background: Coronal seal is one of the essential factors that affects the success of endodontic treatment and reinforces the apical seal. The intra-orifice barrier is an efficient alternative approach to decrease coronal leakage in endodontically treated teeth and various materials have been used for this purpose. This study aimed to compare the coronal sealing of flowable composite, resin-modified glass ionomer (RMGI), and mineral trioxide aggregate (MTA) in endodontically treated teeth. Materials and Methods: In this in vitro study, 35 single-canal canine teeth were divided into five groups, including flowable composite, RMGI, MTA, positive control, and negative control groups. The teeth were filled with restorative materials according to the factory's instructions. Afterward, the samples were immersed in 2% methylene blue dye solution for 1 week at 37°C and 100% humidity condition. Finally, the teeth were sectioned longitudinally and dye penetration was measured using a stereomicroscope with ×10. Data were analyzed with Kolmogorov–Smirnov and Kruskal–Wallis tests (α = 0.05). Results: The positive control group showed the highest amount of dye penetration compared to other groups (12.34 ± 0.46). Dye penetration in the MTA group was significantly lower (4.25 ± 0.31) compared to the RMGI group (5.94 ± 0.24) (P = 0.02). Moreover, while the dye penetration in the MTA group was lower than in the flowable composite group (5.65 ± 0.26), the difference was not statistically significant (P = 0.12). Conclusion: MTA reduces the coronal leakage and provides an acceptable coronal seal in endodontically treated teeth, especially compared to RMGI, and therefore, using MTA as an intra-orifice barrier increases the endodontic treatment success rate.

This study aimed to evaluate and compare the microleakage of composite resin restorations under a total-etch adhesive system applied with two different techniques, with and without cure. Cavities were made on the buccal surface of twenty-six intact teeth and subsequently restored with bulk-fill flow composite resin (SDR®® flow+) and conventional resin (Spectra™ ST HV). Two experimental groups were created, one where the total-etch adhesive (Prime & Bond Active®) was cured and another where the adhesive was not cured before placing the flowable resin. Two control groups were also created, negative and positive. After the restorations were finished the, teeth were submerged in a solution of sodium pertechnetate (99mTcNaO4) for 3 h to evaluate the microleakage. The results showed more infiltration of radioisotopes characterized by the highest total count values of microleakage in group 1 (cured adhesive) and in the positive control. Group 2 (noncured adhesive) and the negative control showed lower values. We therefore considered that these groups were similar since their p-value was less than 0.05, with no statistically significant difference. Group 4 showed a statistically significant increase in relation to group 3 (p = 0.027). We concluded that the method of bulk-fill composite resins with noncured adhesive agents can have a positive effect on the longevity of bond strengths, with reduced microleakage. [ABSTRACT FROM AUTHOR]

Introduction: Self-adhering flowable composite resins were recently introduced to combine the merits of both adhesive and restorative technologies in one product. This study aimed to evaluate the microleakage of a self-adhering flowable composite in comparison with a conventional flowable composite and resinmodified glass ionomer cement in class V cavities. Methods: In this in vitro experimental study, class V cavities were prepared in the buccal and lingual surfaces of 20 sound human molars (40 cavities). The cavities were randomly divided into 4 groups (n=10) and restored with Vertise Flow self-adhering flowable composite in group A, Premise conventional flowable composite in group B, etched with 37% phosphoric acid and restored with OptiBond Solo Plus + Vertise Flow in group C, and Fuji II LC glass ionomer in group D. The specimens were thermocycled for 1000 cycles (5-55°C), immersed in 0.5% basic fuchsine dye solution for 24 h, sectioned, and observed under a stereomicroscope. Data were analyzed by SPSS software using the Kruskal-Wallis, Npar, and Wilcoxon signed rank tests (alpha=0.05). Results: The Kruskal-Wallis test showed that the degree of microleakage was not significantly different among different groups at the enamel margin (P=161) or the dentin margin (P=467). The Wilcoxon signed rank test revealed that the difference in microleakage between the dentin and enamel margins was significant within all four groups (P<0.05). Conclusion: The microleakage of selfadhesive composite, self-adhesive composite with separate etching and bonding, flowable composite, and glass ionomer cement was the same at both dentin and enamel margins. [ABSTRACT FROM AUTHOR]

Background and objectives: Microleakage at the interface of tooth structure and fissure sealant plays a crucial role in failure of the treatment. This in vitro study aimed to determine the microleakage of self-adhesive flowable composite resins as pit and fissure sealants. Material and Methods: 60 healthy extracted premolar teeth were randomly divided into the 4 groups (n=15), group 1) clinpro sealants (control), group 2) flowable composite resin with bonding agent (total-etch), group 3) flowable composite resin with self-etch bonding agent, and group 4) self-adhesive composite resin. After thermocycling the specimens were immersed in 2% methylene blue for 48 hours and then sectioned in the buccolingual direction. The microleakage was assessed by dye penetration using a stereomicroscope at 15X magnification. Data analysis was performed using SPSS version 18.0 as well as Mann-Whitney and Kruskal-Wallis tests. Results: There was a statistically significant difference in microleakage score between the groups (P-value = 0.006). The lowest mean of microleakage level was observed in the flowable composite group with total-etch bonding (group 2) 1.26±0.96, followed by the Clinpro sealant group (group 1) 1.62±1.20, and then the self-adhesive composite group (group 4) 1.85±1.00. Conclusion: Based on the results of this study, the microleakage of self-adhesive composite resin revealed no significant difference with conventional fissure sealant; however, the microleakage of these composite resin was higher than flowable composite resin with total-etch bonding agent.

Introduction: Residual oxygen-free radicals of bleaching agents before composite restorations can increase microleakage in enamel and dentin margins, and also various bleaching techniques are being developed using light sources. The present study was conducted to compare the effect of diode laser bleaching and LED activated bleaching on the microleakage of composite restorations. Materials & Methods: This in-vitro study was conducted on 84 extracted human premolars in three groups: In group one, class-V cavities were prepared and the teeth (n=12) were restored with composite ten days after bleaching with 35% hydrogen peroxide with no activator. In groups two and three (n=36 each), the teeth were bleached with a Diode laser activator and LED, respectively. Thereafter, each group was divided into three subgroups (n=12), cavities were prepared and restored with composite three, five, and ten days after bleaching. Digital photographs were used to assess microleakage in the enamel and dentin margins. Data were analyzed using Friedman and Wilcoxon Signed Ranks tests (p

Abstract 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

Microleakage has always been a problem in restorative dentistry. To decrease microleakage, differentrestorative techniques and materials have been recommended. The purpose of this study was to evaluate micro leakage of the composite restoration in deciduous anterior teeth using the open sandwich technique by two different liners.Materials & Methods:This cross-sectional experimental study was conducted at Khorasgan University in 2019. A total of sixty intact deciduous canine teeth were divided into 3 groups of 20. At the buccal surface of the specimens, the Class V cavity was extracted at 1 mm below the CEJ (Cementoenamel junction) and in groups 1 and 2, ionoseal liner and Fuji II ionomer glass were placed at the buccal floor. Cavities were restored with Z250 composite resin. In group 3 which served as the control, restorations was perfromed without liners. All samples are prepared for establishment after dying in methylene blue 0.5% solution. The buccal lingual incisions with a thickness of 1 mm were inspected under stereo microscope for micro leakage. A total of 5 samples were extracted from each group via random sampling to examine the marginal compliance under SEM (Scanning electron microscope). The intergroup comparisons were made using the chi-square and Kruskal-Wallis tests. Besides, intra-group comparisons were performed using the Mann-Whitney U test. All statistical procedures were performed at a significance level of less than 0.05 (p value < 0.05) using Gpower software.Results:The outcome of this study showed that microleakage of gingival margin in open sandwich techniques with ionoseal and Fuji II (group 1, 2) was significantly higher than in control group (p value = 0.033).but in comparison between group 1,2 there was no significant difference (p value = 0.795).In SEM evaluation there was no significant difference in gingival microleakage (p value = 0.232).Conclusion:Use of two liners: Ionoseal and Fuji II in Class V cavities restored by opensandwich technique in deciduce anterior teeth can reduce gingival microleakage.

Aims: The goal of this study was to analyze the bacterial microleakage following two methods (heat vs. rotary) of postspace preparation after two-time intervals (immediate vs. 1 week later). Setting and Design: In vitro-comparative study. Materials and Methods: Eighty-two single-rooted teeth were decoronated at the cementoenamel junction. Root canals were prepared using rotary files. After root canal obturation, specimens were randomly allocated to 4 experimental groups based on the method of postspace preparation (heat or peeso reamer) and time interval (immediate or 1 week later) (n = 18). Group 1: Peeso reamer-immediate, Group 2: Heat-immediate, Group 3: Peeso reamer-1 week later, Group 4: Heat-1 week later. 10 specimens were considered as positive and negative controls (n = 5 each). Custom-made dual-chamber devices were used to appraise the bacterial microleakage for 60 days. Statistical Analysis Used: Data were analyzed with Chi-Square and Log-Rank tests and Cox regression. Results: All through the experimental period, there was no significant difference (P = 0.41) between the studied groups. Groups 2 and 4 had the highest microleakage and the lowest survival rate (55.56% ± 11.71%). Group 1 showed the lowest microleakage and the highest survival rate (77.8% ± 9.80%). Conclusions: The applied techniques for postspace preparation and the time intervals (neither independently nor simultaneously) showed no significant difference in the field of bacterial leakage.

Introduction: Endodontic instrument separation is one of the iatrogenic errors which may affect the outcome of treatment. The present in vitro study was aimed to investigate the effect of different cross-sectional designs of separated nickel–titanium (Ni-Ti) rotary files on apical microleakage. Materials and Methods: A total of 48 mandibular premolar roots were selected. The samples were randomly assigned to four experimental groups including Mtwo (n = 10), HERO Shaper (n = 10), RaCe (n = 10), and FlexMaster (n = 10) as well as positive (n = 4) and negative (n = 4) control groups. Ni-Ti rotary instruments with the same size and taper (0.06, #30) were separated in the apical region after complete cleaning and shaping, and the remaining root canal was obturated with gutta-percha and AH-26 sealer. The bacterial microleakage of each group was assessed through Enterococcus faecalis for 60 days. Survival analysis was done by SPSS 22. Results: There were no statistically significant differences between the studied groups in terms of the time of microleakage (P = 0.955). Conclusion: The separated Ni-Ti rotary instruments with different cross-sectional designs had no impact on apical microleakage.

Statement of the Problem: A mineral trioxide aggregate (MTA) apical plug is commonly applied prior to endodontic treatment of open-apex teeth. However, difficult application and condensation of MTA in the apical region is a drawback of this technique. Purpose: This study aimed to compare the microleakage of MTA apical plug applied by the manual technique and indirect use of ultrasonic with different powers. Materials and Method: In this in vitro, experimental study, divergent open apices were created in 48 single-rooted, single-canal teeth using ProFile. The teeth were randomly divided into four experimental groups (n=10). All groups received 5-mm thick MTA apical plug at the apical region using one of the following methods. In group 1, MTA was manually condensed while in groups 2-4, indirect ultrasonic energy with minimum, medium, and maximum power levels was used for MTA plug condensation. After setting of MTA, the apical microleakage of the MTA plug was quantified using the fluid filtration method. Data were analyzed using the Mann-Whitney and Kruskal-Wallis tests (p< 0.05). Results: Significant differences were noted in microleakage of MTA plug between the manual group and ultrasonic groups with medium (p= 0.043) and maximum (p= 0.029) power levels. No significant difference was noted in microleakage of other groups (p> 0.05). Conclusion: Considering the current results, it seems that application of MTA with indirect ultrasonic energy at medium or high power level would decrease the microleakage of MTA plug in open-apex root canals.

Statement of the Problem: The dilemma of microleakage at the composite-tooth interface is still a major challenge in operative dental practice. Purpose: This study aimed to compare the microleakage of universal adhesive with selfetch and total-etch bonding strategies for restoration of class-II primary molar cavities. Materials and Method: This in vitro, experimental study was conducted on 75 extracted primary molars. Class-II cavities were prepared in mesial or distal surfaces. The teeth were randomly divided into five groups of Adper Single Bond 2 (3M ESPE; St Paul, MN, USA), Clearfil SE Bond (Kuraray Noritake, Osaka, Japan), G-Bond (GC Corp., Tokyo, Japan), G-Premio Bond (GC Corp., Tokyo, Japan) with total-etch mode and G-Premio Bond with self-etch mode. Cavities were also restored with Nano-hybrid resin composite (Grandio, VOCO, Cuxhaven, Germany) and incubated for 24 hours, followed by thermocycling at 1500× between 5-55°C within a dwell time of 20 seconds. Later, the cavities were placed in 1M silver nitrate solution and evaluated under a stereomicroscope. Finally, microleakage was assessed quantitatively and qualitatively. One tooth in each group was prepared and evaluated under a scanning electron microscope (SEM). Data were analyzed using One-way ANOVA, Tukey's post hoc test and Chi-square test (p< 0.05). Results: The microleakage values were significantly different in the study groups (p< 0.05). The highest level of microleakage was noted in G-Bond and the lowest in G-Premio Bond with total etching. There was a significant correlation between the qualitative and quantitative measurements of microleakage. Conclusion: The G-Premio Bond yielded acceptable results in terms of microleakage in total-etch and self-etch modes. However, additional etching is recommended to improve the quality of bonding. [ABSTRACT FROM AUTHOR]

Objective: This study compared the effectiveness of various cleaning approaches, including spray rinsing, repreparing with diamond burs, and using phosphoric acid or sodium hypochlorite alone or with polyphenols (resveratrol or myricetin), in removing blood contamination from the dentine after adhesive light-curing., Methods: The contact angles of the treated surfaces were measured and scanning electron microscopy/ energy dispersive X-ray spectroscopy observation was performed. The bond strength and nanoleakage were assessed, and in situ zymography was performed before and after aging. Interactions between matrix metalloproteinase (MMP)-9 and polyphenols were evaluated using molecular dynamics and rhMMP-9 inhibition analyses. The destruction of sodium hypochlorite on collagen and the resistance of polyphenols-treated dentine collagen to enzymolysis were evaluated using the hydroxyproline (HYP) assay. The effect of polyphenols on dentine collagen crosslinking was assessed by Fourier Transform Infrared Spectroscopy., Results: The repreparation group had the lowest contact angle compared to the other groups. The spray rinsing group had the lowest bond strength and highest amounts of nanoleakage. Cleaning with phosphoric acid or sodium hypochlorite alone removed the blood contaminants and parts of the adhesive; moreover, applying polyphenols further improved the bond strength and decreased nanoleakage and MMP activity after aging. Both polyphenols inhibited rhMMP-9 activity and promoted collagen crosslinking. Sodium hypochlorite showed the maximum HYP release when used alone, which was decreased after adding polyphenols., Significance: Phosphoric acid or sodium hypochlorite cleaning can remove blood contamination from the dentine surface after adhesive curing, and the addition of polyphenols can improve the durability of dentine bonding., Competing Interests: Declarations of interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: This study aims to evaluate the microtensile bond strength (µTBS) of different resin composite restorations bonded to mid-coronal dentin and proximal root dentin using light-cured, chemical-cured, and dual-cured adhesives immediately and after aging. Nanoleakage and degree of cure were also assessed., Methods: Eighty-four molars were divided into mid-coronal dentin and proximal root dentin. Each group was further subdivided into three subgroups based on the restorative systems used, which involved the utilization of light-cured, chemical-cured, and dual-cured adhesives. Half of the specimens underwent µTBS testing after 24 h, while the other half after aging. Representative specimens were analyzed for nanoleakage. The degree of cure of the tested adhesive systems was also assessed., Results: Aging showed a significant negative effect on µTBS results and led to increased nanoleakage (p < 0.001). Furthermore, in all subgroups, the µTBS values of proximal root dentin were lower compared to mid-coronal dentin, except in the aged subgroup for the system utilizing the dual-cured adhesive. The restorative systems with chemical and dual-cured adhesives demonstrated comparable bonding properties. However, the system with the light-cured adhesive exhibited the worst bonding properties after aging when bonded to proximal root dentin and cured at a large distance (p < 0.05)., Conclusions: All tested restorative systems were negatively affected by aging, and the regional dentin had variable effects on the bonding properties. Clinicians should exercise caution when using the tested light-cured adhesive in areas where the curing distance exceeds 3 mm., (© 2024. The Author(s).)

Background: Apexification is a procedure that promotes apical closure by forming mineralized tissue in the apex region of a nonvital young permanent tooth. Calcium silicate-based cement like Mineral trioxide aggregate (MTA) and Biodentine are commonly employed as apical barriers to facilitate this process. Microleakage, defined as the leakage along the junction between the canal wall and filling material, is a crucial aspect to assess in MTA and Biodentine applications as apical barriers, as it directly impacts the prevention of bacterial seepage and maintenance of structural integrity. The current study aims to assess the microleakage of MTA and Biodentine when used as apical barriers in simulated young permanent teeth., Methods: From a total of 128 extracted teeth, 114 were selected for the study and randomly allocated into three groups: G1 (MTA), G2 (Biodentine), and G3 (Control), with 38 teeth per group. After excluding 5 teeth from each group due to issues such as canal calcification, breakage during sectioning, and procedural errors, 33 teeth were analyzed to ensure equal distribution. To simulate young permanent teeth, samples were instrumented using a person-reamer with a diameter of 1.7 mm. A 4 mm thick apical plug of MTA and Biodentine was placed in G1 and G2, respectively, while G3 was the control group. Apical microleakage in all experimental groups was assessed using a dye penetration method. Specimens were longitudinally sectioned and examined under a stereomicroscope with graded eyepiece., Results: The Kruskal-Wallis test revealed variations in mean apical microleakage among the groups: G1 recorded 0.67, G2-0.16, and G3-1.62, with G2 showing the lowest value and G3 group exhibiting the highest., Conclusions: Biodentine was found to excel in its ability to create a secure seal and function effectively as an apical barrier in simulated young permanent teeth. These results underscore its potential as a highly efficient material for dental applications, particularly in scenarios requiring reliable sealing and barrier formation in the root canal system of developing permanent teeth., (© 2024. The Author(s).)

Evaluation of micro tensile bond strength (μTBS) and marginal leakage of sodium fluoride (NaF) and nano-hydroxyapatite (n-HA) modified universal adhesives (UAs) bonded using etch-and-rinse (ER) and self-etch (SE) bonding technique to the carious affected dentin (CAD). One hundred and twenty primary molars were prepared for CAD on the occlusal surface. The occlusal CAD surface was flattened and underwent a polishing procedure. The specimens were divided into six groups using a random allocation method based on the UAs applied and the mode of etching used (n = 20) Group A1: UAs (ER), Group B1: UAs (SE), Group A2: UAs (NaF) + ER, Group B2: UAs (NaF) + SE, Group A3: UA (n-HA) + ER and Group B3: UAs (n-HA) + SE. Composite restoration was placed and samples were thermocycled. Microleakage, μTBS, and failure mode assessment were performed using a dye penetration test, universal testing equipment, and stereomicroscope respectively. The μTBS and microleakage results (mean ± SD) were examined using analysis of the variance (ANOVA) and Tukey post hoc tests. Group B1 (UAs + SE) demonstrated the maximum scores of microleakage (25.14 ± 9.12 nm) and minimum recorded value of μTBS (14.16 ± 0.55 MPa). In contrast, Group A3 (UAs (n-HA) + ER) displayed a minimum value of marginal leakage (12.32 ± 6.33 nm) and maximum μTBS scores (19.22 ± 0.92 MPa). The outcomes of the intergroup comparison analysis showed that Group A2 (UAs (NaF) + ER), Group B2 (UAs (NaF) + SE), Group A3 (UA (n-HA) + ER) and Group B3 (UAs (n-HA) + SE) presented comparable outcomes of marginal seal outcomes and μTBS scores ( p > 0.05). NaF and n-HA-modified UAs displayed favorable bond strength and minimum marginal leakage to the deciduous affected dentin surface., Competing Interests: The authors declare no conflict of interest., (©2024 The Author(s). Published by MRE Press.)

This research was aimed to evaluate push-out bond strength and apical-microleakage after application of three different calcium silicate-based cements with irrigation solutions on simulated immature teeth. 40 maxillary permanent canine teeth were used for push-out bond strength test, and 120 maxillary permanent incisors were used for microleakage evaluation. 120 root slices were divided into four main groups (EDTA, Chitosan, Phytic acid, and Saline) and immersed these solutiouns according to irrigation procedures. Each irrigation group was divided into 3 subgroups (Biodentine, MTA Repair HP, and NeoPUTTY). The prepared teeth were divided into four groups according to irrigation procedure for microleakage test. EDTA irrigation with Biodentine group showed highest push-out bond strength value and saline group with Neoputty showed the lowest push-out bond strength value. The highest microleakage value was seen in saline group with MTA Repair HP, while the lowest microleakage value was observed chitosan with Biodentine group. Chitosan and phytic acid solutions can be recommended as an alternative irrigation solution to 17% EDTA in single-session apexification treatment, since they are non-toxic, naturally occurring materials, effectively remove the smear layer, and have a positive effect on bond strength and apical leakage. RESEARCH HIGHLIGHTS: One of the factors affecting the long-term success of root canal treatment is a hermetic seal. Non-hermetic or inadequate filling triggers a chronic inflammatory reaction in periapical tissues, causing fluids to enter the spaces and negatively affecting the success of the treatment. Therefore, this study will help clinicians choose the right biomaterial and irrigation solution that will affect the success of root canal treatment., (© 2024 Wiley Periodicals LLC.)

Background and Aim: This study assessed the effects of cyclic loading on screw loosening, vertical misfit, and microleakage at the fixture-angulated abutment interface. Materials and Methods: This in vitro study evaluated 12 implants in two groups (n=6). The implants were mounted in self-cure acrylic resin. The abutment screw was torqued to 30 N/cm by a digital torque-meter and re-torqued after 5 min. Six points at the fixture-abutment interface were inspected under a stereomicroscope (x75 magnification), and the distance between the two reference points was measured. Six implant-abutment assemblies then underwent cyclic loading (75 N, 1 Hz, 500,000 cycles) while the remaining six (control group) were stored at room temperature. The distance was measured again at the same 6 points after cyclic loading. Vertical misfit was calculated by subtracting the before and after values. The torque loss was measured by a digital torque-meter. The assemblies were then immersed in fuchsine and incubated at 37°C for 24 h. Next, the abutment was unscrewed and the fixtures were cut in half. The penetration depth of fuchsine was measured at 3 points of each fixture half under a stereomicroscope at x75 magnification, and the mean of the six measurements (entire fixture) was reported as the microleakage score of each sample. Data were analyzed using t-test. Results: Cyclic loading significantly increased the misfit (P=0.001) and microleakage (P=0.01), and decreased the detorque value (P=0.04). No case of screw loosening was noted in any group. Conclusion: Cyclic loading significantly increases the vertical misfit, microleakage, and torque loss.

Objective: To evaluate the microleakage at the junction between amalgam-composite resin restorations using different bonding systems. Material and Methods: In this in-vitro study, standard class II cavities were prepared on 40 human maxillary premolars. The axial and gingival floor depths of the cavities were 2 mm and 1 mm below (cementoenamel junction), respectively. The samples were divided into 4 groups (n = 10). In all groups, a layer of 1-mm thick amalgam was used as a coating for the initial part of the gingival floor. In group 1, no bonding system was used for amalgam restoration. In group 2, G-Premio Bond was applied. G-Premio bond + alloy primer and single bond + alloy primer were used in group 3 and group 4, respectively. The rest of the cavities in all groups were then repaired using FiltekZ250 composite. The samples were thermocycled at 500 rpm and immersed in 1% methylene blue solution for 24 hours to allow dye penetration. Once cut, the samples were placed under a stereomicroscope (40X) to determine the microleakage rate. Data analysis was carried out using post-hoc and Chi-square tests (p

The essential factor in determining the preservation of restoration is the marginal seal. Restoring cervical lesions with a resin composite has always been a challenge. Composite resins with various viscosities and different bonding systems are being researched to reduce the microleakage. Confocal laser scanning microscopy (CLSM) is the latest non-destructive technique for visualizing the microleakage. Objectives: To evaluate and compare the microleakage of Universal Flo composite resin (G-aenial) using etch and rinse adhesive system ER-2 steps (Adper Single Bond 2), self-etch adhesive system SE-1 step (G-Bond), and self-adhesive flowable composite resin (Constic) in Class V cavities using a confocal laser scanning microscope. Materials and Method: Class V cavities were prepared on 27 caries-free human extracted premolar teeth on the buccal and lingual surfaces with standardized dimensions of 2 mm height, width 4 mm, and a depth of 2 mm. After the cavity preparation, all teeth were randomly divided into three groups, namely Group-I: G-aenial Universal Flo with Single Bond 2 (n = 9 teeth); Group-II: G- aenial Universal Flo with G-Bond (n = 9 teeth), and Group-III: Constic (n = 9 teeth). The prepared and restored specimens were then subjected to thermocycling for 500 cycles in a water bath at 5 °C and 55 °C with a dwelling time of 30 s. The specimens were placed in 0.6% aqueous rhodamine dye for 48 h. Sectioning was carried out bucco-lingually and specimens were evaluated for microleakage under a confocal laser scanning microscope. Results: There was a significant difference (p = 0.009) in microleakage when comparing total etch and rinse, specifically between Adper Single Bond 2 ER-2 steps (fifth generation) and self-adhesive flowable composite resin, which is Constic. There was more microleakage in the self-etch bonding agent, particularly G-Bond, SE-1 step (seventh generation), when compared to ER-2 steps (fifth generation bonding agent); however, the results were not statistically significant (p = 0.468). The self-adhesive flowable composite resin showed more microleakage than SE-1 step and ER-2 steps. Conclusions: None of the adhesive systems tested were free from microleakage. However, less microleakage was observed in the total etch and rinse, especially Adper Single Bond 2 (ER-2 steps), than the self-etch adhesive system SE-1 step and self-adhesive flowable composite resin. Clinical significance: Constant research and technological advancements are taking place in dentin adhesives to improve the marginal seal. This has led to the evolution of total acid-etching dentin bonding agents termed as etch and rinse (ER)-2 steps (fifth generation dentin bonding agents) and self-etching (SE) 2 steps, and SE-1 step dentin bonding agents termed as the sixth and seventh generation bonding agents, respectively. [ABSTRACT FROM AUTHOR]

Aims: The goal of this study was to analyze the bacterial microleakage following two methods (heat vs. rotary) of postspace preparation after two-time intervals (immediate vs. 1 week later). Setting and Design: In vitro-comparative study. Materials and Methods: Eighty-two single-rooted teeth were decoronated at the cementoenamel junction. Root canals were prepared using rotary files. After root canal obturation, specimens were randomly allocated to 4 experimental groups based on the method of postspace preparation (heat or peeso reamer) and time interval (immediate or 1 week later) (n = 18). Group 1: Peeso reamer-immediate, Group 2: Heat-immediate, Group 3: Peeso reamer-1 week later, Group 4: Heat-1 week later. 10 specimens were considered as positive and negative controls (n = 5 each). Custom-made dual-chamber devices were used to appraise the bacterial microleakage for 60 days. Statistical Analysis Used: Data were analyzed with Chi-Square and Log-Rank tests and Cox regression. Results: All through the experimental period, there was no significant difference (P = 0.41) between the studied groups. Groups 2 and 4 had the highest microleakage and the lowest survival rate (55.56% ± 11.71%). Group 1 showed the lowest microleakage and the highest survival rate (77.8% ± 9.80%). Conclusions: The applied techniques for postspace preparation and the time intervals (neither independently nor simultaneously) showed no significant difference in the field of bacterial leakage. [ABSTRACT FROM AUTHOR]

Abstract Background Bacterial microleakage is an important cause of apical periodontitis and endodontic treatment failure. This study aimed to assess the bacterial microleakage of nano-mineral trioxide aggregate (nano-MTA) as a sealer, Endoseal MTA, and GuttaFlow Bioseal sealers in atmospheric pressure, and simulated underwater diving and aviation conditions. Methods In this in vitro, experimental study, 180 extracted single-rooted teeth were cleaned and shaped, and were then randomly divided into three groups for single-cone obturation using Endoseal MTA, GuttaFlow Bioseal, or nano-MTA as a sealer. Each group was then randomly divided into three subgroups, and subjected to ambient atmospheric pressure, 2 atm pressure (to simulate underwater diving), and 0.5 atm pressure (to simulate aviation) using a custom-made pressure chamber. The teeth then underwent microbial leakage test using Streptococcus mutans (S. mutans), and the percentage of samples showing microleakage was recorded for up to 1 month, and analyzed using the Chi-square test. Results The three sealer groups were significantly different regarding bacterial microleakage (P 0.05). Conclusion Within the limitations of this in vitro study, it may be concluded that single-cone obturation technique using nano-MTA as a sealer results in lower resistance to bacterial microleakage compared with the use of GuttaFlow Bioseal, and Endoseal MTA. Pressure changes in simulated underwater diving and aviation conditions had no significant effect on bacterial microleakage. Trial Registration Number This is not a human subject research.

Statement of the Problem: Different materials have been used to repair root perforations, the most successful of which is mineral trioxide aggregate (MTA). It is technically difficult to use MTA for perforation repair. Recently, some bio-ceramic sealers such as Endoseal MTA were introduced to repair the perforation site during root filling, which decreases the technical difficulty of this procedure. Purpose: The aim of this study was to compare the bacterial microleakage of Pro-Root MTA and Endoseal MTA sealer in root perforation repair. Materials and Method: This in vitro experimental study evaluated 40 extracted canine teeth. After root canal cleaning and shaping, a root perforation was artificially created at 7 mm below the cementoenamel junction. The teeth were then randomly divided into two experimental groups (n=18) of Pro-Root MTA and Endoseal MTA, and two positive and negative control groups (n=2). Perforation sealing and root canal filling were performed in the two experimental groups according to the manufacturers’ instructions. After sterilization of the whole system with gamma ray, microleakage was tested using a double-chamber model. Data regarding the presence/absence of microleakage were reported after 35 days. The data were analyzed by SPSS software using the Chi-square test. Results: There was no significant difference between the two experimental groups regarding bacterial microleakage (p> 0.05). Conclusion: Under the conditions of this study, it can be concluded that the sealing ability of perforation repair with Endoseal MTA Sealer and Pro-Root MTA was comparable.