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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.

Objectives: To investigate debonding of full crowns made of CAD/CAM composites, CAD/CAM technology was applied to manufacture standardized test abutments to increase the reproducibility of human teeth used in in vitro studies., Materials and Methods: A virtual test abutment and the corresponding virtual crown were designed and two STL data sets were generated. Sixty-four human third molars and CAD/CAM blocks were milled using a CNC machine. Crowns of four different composite blocks (Lava Ultimate (LU), Brilliant Crios (BC), Cerasmart (CS), Experimental (EX)) were adhesively bonded with their corresponding luting system (LU: Scotchbond Universal/RelyX Ultimate; BC: One Coat 7 Universal/DuoCem; CS: G-PremioBond/G-Cem LinkForce; EX: Experimental-Bond/Experimental-Luting-Cement). Half of the specimens were chemical-cured (CC) and the others were light-cured (LC). Afterwards, specimens were artificially aged in a chewing simulator (WL-tec, 1 million cycles, 50-500 N, 2 Hz, 37 °C). Finally, a dye penetration test was used to detect debonding. For inspection, the specimens were sliced, and penetration depth was measured with a digital microscope. Data were analyzed with the Mann-Whitney U test., Results: No cases of total debonding were observed after cyclic loading. However, the LC specimens showed a significantly lower amount of leakage than the CC ones (p < 0.05). Furthermore, the CC specimens exhibited broad scattering. Only the LC-EX blocks showed no debonding. The CC-CS blocks showed the highest leakage and scattering of all tested specimens., Conclusions: Natural human teeth can be manufactured by CAD/CAM technology in highly standardized test abutments for in vitro testing. For CAD/CAM composites, light curing should be performed., Clinical Relevance: The success of a restoration depends on the long-term sealing ability of the luting materials, which avoids debonding along with microleakage. For CAD/CAM composites, separate light curing of the adhesive and luting composite is highly recommended.

Purpose: To determine the influence of iatrogenic gaps, type of cement, and time on microleakage of cast posts using spectrophotometer and glucose filtration measurements., Materials and Methods: Forty-eight single-rooted teeth were divided into eight groups of six teeth each. Teeth were instrumented and obturated, and a cast post was fabricated. In addition to two control groups (positive and negative), a total of six groups were prepared: In four groups, an artificial 2- to 3-mm gap was created between post and residual gutta percha (GP), and two groups were prepared with intimate contact between post and residual GP. Posts were cemented with either zinc phosphate cement or resin cement. Leakage through the post after 1, 8, 14, and 20 days was measured using a glucose penetration model with two different reading methods. Mixed analysis of variance tests were performed to analyze the data., Results: The presence of a gap between the apical end of the post and the most coronal portion of the GP remaining in the root canal after post space preparation increased microleakage significantly. However, microleakage was significantly less when the gap was refilled with GP compared to no gap. There was no difference in leakage between luting cements used., Conclusion: It was concluded that none of the cements were able to prevent microleakage. However, the addition of GP to residual GP did increase the sealing ability.

Objective: The objective of this study is to evaluate the influence of a calcium hydroxide intracanal dressing (CH) on the short- and long-term sealing ability of the root canal filling using capillary flow porometry (CFP)., Materials and Methods: To verify the repeatability of the method, five obturated specimens were submitted to CFP. Measurements were repeated three times and compared with the non-parametric Friedman test. Forty-five instrumented palatal roots were randomly divided into three groups. Group 1: specimens were obturated in one step without placement of any dressing. Group 2: CH was placed and removed after 1 week with syringe irrigation before obturation. Group 3: CH was placed and removed after 1 week with ultrasonic activation before obturation. CFP measurements were conducted at 1 week and 6 months after obturation. The inter-group comparisons were performed using the Kruskal-Wallis test and the intra-group comparison over time using the Wilcoxon signed-rank test. Significance level was set at 0.05., Results: In the five specimens, no difference could be detected between the consecutive measurements for minimum, mean flow, and maximum pore diameter indicating repeatability of the method. No difference in sealing ability could be detected neither between the 3 groups at 1 week and at 6 months nor within each group between the 1 week and the 6 months measurements., Conclusions: Placement of a CH did not affect significantly the short- and long-term sealing ability of the root canal filling., Clinical Relevance: The use of an intermediary CH does not negatively influence the quality of the root canal filling.

Background and Aim: This study aimed to examine the microleakage of class V cavities of primary molars prepared by either a conventional dental bur or Er:YAG laser and one of two different adhesive systems., Methods: A total of 50 tooth samples from primary molars were used in this study. They were randomly assigned into five experimental groups of 10 samples each, according to the cavity preparation technique and the type of adhesive system applied to the cavities. Following cavity preparation, etching, bonding, and filling steps, samples were dyed using basic fuchsine and were sectioned longitudinally in buccolingual direction. Percentages of dye penetration at gingival and occlusal margins were calculated for each group., Results: Overall, microleakage scores of gingival margins were significantly higher than those of occlusal margins (P < 0.001). The group that underwent laser preparation, laser etch, and self-etch bonding procedures had worse microleakage scores for gingival margins. However, all groups had similar occlusal scores (P > 0.05)., Conclusion: Self-etch bonding systems and cavity preparation with Er:YAG laser may be an alternative to conventional restoration of primary molars with compomers. Further studies are warranted to fully elucidate the effect of laser-based etching techniques in cavities prepared by laser., Competing Interests: There are no conflicts of interest.

Objective: To compare the microleakage of MTA (mineral trioxide aggregate) and resin-modified GIC (glass ionomer vitremer) as retrograde endodontic material., Study Design: Experimental study., Place and Duration of Study: Operative Department of DIIKIOHS (DUHS) and NED University, Karachi, from February to June 2014., Methodology: Forty human anterior teeth were divided into four groups. Each tooth was endodontically treated. Apical cavity preparations were performed on all teeth. The retropreparations were filled either with MTA (Group 1), Vitremer (Group 2), or only covered with nail polish (Group 3). The root surfaces of the first three groups were coated with nail polish. In Group 4 (positive control), neither retrograde filling was placed nor the nail polish was applied. The teeth were then suspended in 2% methylene blue dye solution for 10 days at 37°C. Sections were made along the long axis of teeth to determine the depth of linear dye penetration. Using Mann-Whitney test the comparison, p-value <0.05 was considered as statistically significant., Results: MTA had no significant difference in apical dye leakage (p = 0.122) than did the vitremer., Conclusion: MTA is equivalent to vitremer in preventing microleakage when used as retrograde filling material.

Introduction: Creation of a tight seal in endodontically treated root canals is of utmost importance. Clinical and laboratory studies have a great role in the assessment of the sealing ability of endodontic materials. The present review was undertaken to evaluate correlation between different techniques used in microleakage studies in endodontics and the potential laboratory errors., Evidence Acquisition: A systematic search was run using Medline, Biosis, Cochrane Database, Embase, Google Scholar, and Web of Science databases. Furthermore, the reference lists of the articles published on the subject were thoroughly searched. There was no language restriction in the search. Two reviewers separately evaluated the titles and abstracts., Evidence Synthesis: All the methods used might have proved useful if the study could have been carried out with a larger sample size, with carefully designed control groups. Furthermore, extra evaluations are recommended on the reliability of the method used. Examinations like glucose reactivity test, assessment of antimicrobial activity of the tested materials and in situ FISH examination for the reliability of bacterial leakage model have been recommended. It has been recommended that two or more methods be considered for each material in the same study. On the other hand, long-term animal studies can be useful with histological and radiographic evaluations for meticulous assessment of leakage. Furthermore, long-term clinical trials on humans might be helpful on the condition that confounding factors are controlled., Conclusions: Studies on microleakage should be focused on animal studies, clinical trials or laboratory tests. On the basis of available evidence, it appears that despite potential errors on microleakage studies they are very valuable.

Introduction: The aim of the study was to evaluate the in vitro microleakage of new flowable compomers in the class V cavities of primary teeth., Methods: Thirty freshly extracted, non-carious, primary molars without visible defects were used in this study. Class V cavities (n = 60), with the occlusal and cervical margins located in the enamel, were prepared on the buccal and lingual surfaces. The samples were randomly divided into 3 groups of 20 each. Group 1: restored with Twinky Star Flow (Voco, Cuxhaven, Germany), Group 2: restored with Dyract Flow (Dentsply, Konstanz, Germany) and Group 3: restored with R&D Series Nova Compomer Flow (Imicryl, Konya, Turkey) according to the manufacturer's instructions. After a thermocycling regimen of 1000 cycles between 5°C and 55°C, the samples were isolated, immersed in 0.5% basic fuchsine solution for 24 h at 37°C and sectioned longitudinally in a buccolingual direction. The sections were evaluated for values of microleakage with a stereomicroscope., Results: All materials showed microleakage but no statistically significant difference was observed among the groups (p&gt;0.05). The highest microleakage score was observed in group II (1.65 ± 0.49) and group I (1.75 ± 0.44) at occlusal and gingival margins, respectively., Conclusions: Flowable compomers showed insignificantly least amount of microleakage in class V cavities prepared on primary molars.

Objective: To evaluate the influence of different polishing methods on marginal microleakage of zirconium dioxide full crown., Methods: Thirty extracted premolars were selected and randomly divided into three groups, A, B and C, with 10 in each group. Group A was prepared with MANI TF-13 bur completely without the treatment of shoulder. The shoulder of group B was polished with MANI TR13-EF bur after the preparation using MANI TF-13. The shoulder of group C was polished with the dental pneumatic ultrasonic hand-piece of KaVo SONICflex after the preparation using MANI TF-13 bur. Five specimens after preparation were selected in each group. Fifteen CAD/CAM zirconium dioxide full crowns have been made. The crowns were bonded using PULPDENT resin cement, and the root canals were sealed using nail polish, and apical foramen were closed using flow resin. The test-pieces have been immersed in a 3% solution of methylene blue for 24 h. The condition of shoulder marginal microleakage was observed using light stereomicroscopy and evaluated in classification index. The remaining specimens in each group were used for roughness test and scanning electron microscope(SEM) experiment. The marginal microleakage situations of specimens in three groups was analyzed by SPSS 17.0. The enamel surface of different polishing methods was observed using SEM., Results: The specimens in group C demonstrated the least marginal microleakage, and those in group B showed an intermediate level of marginal microleakage, and those in group A characterized the most serious marginal microleakage (total, χ2=44.610, P<0.01; among the different groups, P<0.05). The roughness experiment showed that specimens in group C achieve the smoothest results ([0.27±0.03] μm). Preparation shoulder polished using the dental pneumatic ultrasonic hand-piece demonstrated the best result under the SEM among the three groups., Conclusions: The anti-microleakage effectiveness of dental pneumatic ultrasonic hand-piece in shoulder refinement is better than ordinary shoulder treatment.

This study investigated the influence of adhesives and marginal sealing on demineralization progress using optical coherence tomography (OCT). Cavities (4 × 2 mm) were prepared in bovine incisors and restored using Clearfil SE Protect (SP), Bond Force (BF), Scotchbond Universal (SB), or G-Bond Plus (GB), followed by Estelite Flow Quick flowable composite. The control group received no adhesive (n = 10). After 3-d incubation in artificial saliva and 10,000 thermal cycles, gaps at enamel and dentin margins were measured at 8 locations on cross-sectional images obtained from each restoration using swept-source OCT at 1310-nm wavelength. Specimens were demineralized using acidified gel (pH = 4.5) for 5 wk and scanned every week to monitor the lesion progress at the same marginal locations. Repeated-measures analysis of variance showed that demineralization period and adhesive type and their interaction had a significant effect on the lesion size in both substrates (P < 0.001). SP, BF, and SB had significantly lower enamel and dentin initial gaps than the control and GB (P < 0.05). Enamel lesion progress was slower in the fluoride-releasing adhesives SP and BF and significantly different from SB, GB, and the control (P < 0.001). SP and BF dentin lesions were significantly different from GB and the control (P < 0.001), but not from SB (P > 0.05). A significant positive correlation (P < 0.05) was found between initial gap length and formed lesion size in both substrates, which was stronger in enamel (r = 0.63) than dentin (r = 0.35). Microgaps forming at the margins of restorations depend on adhesives and significantly contribute to the progress of demineralization around the margins, while fluoride release may decrease the rate of progression., (© International & American Associations for Dental Research 2015.)

Aims: To assess the accuracy and sensitivity in detecting implants leakage with a gas-enhanced permeation test (GEPT) and to compare with a molecular- and a bacterial-based leakage tests., Materials and Methods: Three implants systems were tested (n = 20 per group): Nobel Biocare (NB), Astra Tech (AT) and Biomet 3i (B3i). Implants were mounted in PVC disks and were first tested for gas pressure change and infiltrated saline volume over 40 min. The same implants were then subjected to a molecular leakage evaluation using fluorescent Dextran for 28 days. After cleaning and sterilization, bacterial permeation (E. faecalis) was evaluated by selective media turbidity for another 28 days. Slopes in the pressure change and the perfused saline rate were used as a measure of leakage in the GEPT model and the times of positive events, that is, color change, after molecular and bacterial tests were recorded. Data were analyzed using Kolmogorov-Smirnov/Shapiro-Wilk, Kruskal-Wallis H and Spearman's Rho tests (P < 0.05)., Results: The gas and saline (ml) leakage values accounted for 0.85 ± 0.71 and 0.56 ± 0.50 ml (AT), 0.23 ± 0.030 and 0.12 ± 0.20 ml (NB) and 0.01 ± 0.01 and 0 ± 0 ml (B3i), respectively, and were significantly different from each other (P < 0.001). Slope in the pressure change over time showed a significant positive correlation with the collected saline solution (r = 0.91; P < 0.001). Molecular and bacterial leakage was positive at the same implants, which also showed increased leakage values in the GEPT setup. The development of positive events in the timeline of the bacterial leakage evaluation corresponded well to the GEPT leakage model., Conclusion: The GEPT proved to be a reliable method to quantify leakage. The B3i showed the best sealing among the tested systems., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The objective of this study was to describe a new method for the quantitative analysis of a microleakage of endodontic filling materials. Forty extracted single-rooted teeth were randomly divided into three experimental groups. After root canal shaping, the experimental groups were filled using the lateral condensation technique with the Epiphany system (G1), with gutta-percha + Sealapex (G2), and with gutta-percha + AH Plus (G3). Each root was mounted on a modified leakage testing device, and caffeine solution was used as a tracer (2000 ng mL-1, pH 6.0), applied in the coronal direction towards the tooth apex, creating a hydrostatic pressure of 2.55 kPa. Presence of caffeine in the receiving solution was measured after 10, 30, and 60 days, using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). None of the groups presented microleakage at 10 days. At 30 days, G2 and G3 showed similar infiltration patterns (means: 16.0 and 13.9 ng mL-1, respectively), whereas G1 showed significantly higher values (mean: 105.2 ng mL-1). At 60 days, leakage values were 182.6 ng mL-1 for G1, 139.0 ng mL-1 for G2, and 53.5 ng mL-1 for G3. AH Plus showed the best sealing ability and HPLC-MS/MS showed high sensitivity and specificity for tracer quantification.

Introduction: The aim of this study was to compare the leakage at the implant to abutment connection in several implants, using a new gas diffusion method., Material and Methods: Sixty-eight implants of 13 different types were used. Nitrogen leaking was measured after screwing the connections to the torque levels recommended by the manufacturers., Results: A significant tightness difference was observed between the different implant types. This difference cannot be explained by the various connection designs (flat, conical) or by the various torques recommended by the manufacturers., Conclusion: The authors suggest that the tightness difference between the various implant systems could be mainly associated with quality and precision of machining., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Purpose: To evaluate the effect of the presence of a prefabricated cobalt-chromium (CoCr) margin in a universal castable long abutment (UCLA) on the sealing capability and fit of the implant-abutment interface., Materials and Methods: One-hundred twenty external hexagon implants (SIN) were divided into two groups (n=60 each) to receive UCLA abutments from six manufacturers (n=10 each) either with or without a CoCr margin (n=60 each). Abutments were cast and 12 groups were formed: M (Microplant), I (Impladen), S (SIN), Sv (Signo Vinces), T (TitaniumFix), and B (Bionnovation). Sealing was determined by placing 0.7 µL of 0.1% toluidine blue in the implant wells before abutment torquing. Implant-abutment samples were placed into 2.0-mL vials containing 0.7 mL of distilled water to maintain the implant-abutment interface, and aliquots of 100 µL of water were retrieved at 1, 3, 6, 24, 48, 72, 96, and 144 hour incubation times for measurement of absorbance in a spectrophotometer, and returned for repeated measurements. Two-way ANOVA (P<.05) and Tukey's test were used. Scanning electron microscopy (SEM) was used for observation of the implant-abutment fit., Results: Groups M, Sv, and T without the CoCr margin resulted in complete release of toluidine blue at 1 hour, whereas I, S, and B did so at 3, 24, and 96 hours, respectively. Complete leakage in abutments with the prefabricated margin occurred at 6 hours for S; 24 hours for Sv, T, and B; and 72 hours for M and I. Implant-abutment gaps were observed in all groups. A poorer fit was depicted for groups M and T without the CoCr margin., Conclusion: Complete leakage was observed for all UCLA abutments regardless of the presence of the CoCr margin. Implant-abutment gaps were observed in all groups.

Background: The aim of this study was to evaluate the effect on microleakage in Class V restorations of daily applications of artificial saliva, fluoride mouthrinses and chlorhexidine to irradiated bovine teeth., Methods: Class V cavities were created in 60 bovine teeth. The teeth were divided randomly into two groups: the first group (n = 30) was subjected to radiotherapy until the teeth had received a total accumulated dose of 60 Gy; the second group (n = 30) was used as a control group. Both groups were divided into three subgroups (n = 10): in Group A teeth were submerged in Xeros Dentaid(®) artificial saliva; Group B teeth were submerged in a solution of 1% amine fluoride; Group C teeth were submerged in 0.12% chlorhexidine. All treatments were applied three times a day for six weeks. Afterwards microleakage into the composite restorations was measured using MIP4 image software., Results: It was seen that radiation caused increases in microleakage in composite restorations. Statistically significant differences were found in the artificial saliva group (p = 0.013) and the chlorhexidine group (p = 0.023)., Conclusions: Microleakage in composite restorations was greater among radiated teeth., (© 2013 Australian Dental Association.)

This study focused on adhesive interface morphologic characterization and nanoleakage expression of resin cements bonded to human dentin pretreated with 1% chlorhexidine (CHX). Thirty-two non-carious human third molars were ground flat to expose superficial dentin. Resin composite blocks were luted to the exposed dentin using one conventional (RelyX ARC) and one self-adhesive resin cement (RelyX U100), with/without CHX pretreatment. Four groups (n = 8) were obtained: control groups (ARC and U100); experimental groups (ARC/CHX and U100/CHX) were pretreated with 1% CHX prior to the luting process. After storage in water for 24 h, the bonded teeth were sectioned into 0.9 × 0.9 mm(2) sticks producing a minimum of 12 sticks per tooth. Four sticks from each tooth were prepared for hybrid layer evaluation by scanning electron microscope analysis. The remaining sticks were immersed in silver nitrate for 24 h for either nanoleakage evaluation along the bonded interfaces or after rupture. Nanoleakage samples were carbon coated and examined using backscattered electron mode. Well-established hybrid layers were observed in the groups luted with RelyX ARC. Nanoleakage evaluation revealed increase nanoleakage in groups treated with CHX for both resin cements. Group U100/CHX exhibited the most pronouncing nanoleakage expression along with porous zones adjacent to the CHX pretreated dentin. The results suggest a possible incompatibility between CHX and RelyX U100 that raises the concern that the use of CHX with self-adhesive cements may adversely affect resin-dentin bond., (Copyright © 2013 Wiley Periodicals, Inc.)

The aim of this paper was to evaluate a possible correlation between obturation limits and leakage. Thirty-six extracted human mandibular incisors were used, characterized by straight and single canals, non-anatomical complexities, absence of previous endodontic treatment, complete root formation and patent foramen. For standardization of the specimens for the leakage analysis, foraminal instrumentation was performed up to a Flexofile #25 (Dentsply-Maillefer, Ballaigues, Switzerland). All specimens were instrumented and filled following the same protocol, and the obturation limits were measured using Axiovision 4.5 Software (Carl Zeiss Vision, Hallbergmoos, Germany). The specimens were then separated into three groups (n=12) according to the following variables: Group I--obturation limits ranging from 0 mm to 0.76 mm of the main apical foramen. Group II--obturation limits ranging from 0.77 mm to 0.98 mm of the main apical foramen. Group III--obturation limits ranging from 0.99 mm to 1.68 mm of the main apical foramen. Apical leakage was quantified by fluid filtration. The analyses were confronted using Pearson's test (p>0.05). Groups I, II and III showed Pearson correlation values (r2) of -0.152, -0.186 and 0.058, respectively. No correlation was found between the obturation limits and apical leakage.

This study compared the microleakage of class V restorations bonded with various one-step self-etching adhesives. Seventy class V resin-based composite restorations were prepared on the buccal and lingual surfaces of 35 premolars, by using: Clearfil S3 Bond, G-Bond, iBond, One Coat 7.0, OptiBond All-In-One, or Xeno IV. The Adper Single Bond etch-and-rinse two-step adhesive was employed as a control. Specimens were thermocycled for 500 cycles in separate water baths at 5°C and 55°C and loaded under 40 to 70 N for 50,000 cycles. Marginal microleakage was measured based on the penetration of a tracer agent. Although the control showed no microleakage at the enamel margins, there were no differences between groups (p = 0.06). None of the adhesives avoided microleakage at the dentin margins, and they displayed similar performances (p = 0.76). When both margins were compared, iBond® presented higher microleakage (p < 0.05) at the enamel margins (median, 1.00; Q3-Q1, 1.25-0.00) compared to the dentin margins (median, 0.00; Q3-Q1, 0.25-0.00). The study adhesives showed similar abilities to seal the margins of class V restorations, except for iBond®, which presented lower performance at the enamel margin.

Introduction: Bovine teeth are commonly used as substitutes for human teeth in scientific investigations. The present study was performed in vitro with the objective of comparing bovine and human enamel subjected to thermocycling for microleakage beneath metal brackets., Materials and Methods: A total of 50 bovine and human teeth (25 per group) void of defects or carious decay were extracted and stored in chloramine B (0.5%). A light-curing adhesive (Transbond™ XT) was used as instructed by the manufacturer (3M Unitek, Monrovia, CA, USA) to bond a metal bracket (discovery®; Dentaurum, Ispringen, Germany) to the surface of each tooth following 30 s of enamel etching (phosphoric acid 35%). After 24 h of dye penetration in methylene blue (0.5%), the cervical and incisal bracket surfaces were analyzed by light microscopy for excess bonding material, dye penetration, and microleakage at the bracket-adhesive and adhesive-enamel interfaces. Staining and evaluation was repeated after thermocycling (5000 cycles at 5/55 °C)., Results: Before thermocycling, the number of human teeth showing marginal gaps was one-third the number of bovine teeth (p<0.001). After thermocycling, the distribution of gaps was similar (p=0.180). The adhesive-enamel interface was most frequently affected (on 74% of human and 64% of bovine teeth). No dye penetration in either group after examining a horizontal slice through the bracket basis was observed., Conclusion: Immediately after bonding, less microleakage was observed around the base of metal brackets on human than bovine teeth. These marginal gaps were, however, superficial in both groups, none of them involving deep penetration of dye under the bracket base.

Purpose: The aim of this study was to evaluate, with a new gas flow technique, leakage at the implant/abutment junction in systems with four different connections., Materials and Methods: Five Branemark System, five One Morse, five Intra-lock System, and five Ankylos Plus implants and abutments were used. A hole was drilled in the apex of each implant to allow gas to flow through the connection from negative to atmospheric pressure. The gas flow was calculated (slope of pressure decrease, in hPa.s-1). Each connection was tested after both manual and key tightening. Statistical analysis was performed on a generalized linear model with repeated measurements. The significance level was set at α=.05., Results: A global significant difference was observed between the various systems (P=.0001). After manual tightening, gas leakage was (Ln[hPa.s-1], means±standard deviations): One Morse: 0.20 (±1.70); Branemark System: -4.56 (±2.61); Intra-lock: -4.31 (±4.17); Ankylos Plus; -7.59 (±0.76). After key tightening, mean values were: One Morse: -2.51 (±2.72); Branemark System: -7.23 (±1.01); Intra-lock: -7.76 (±0.50); Ankylos Plus; -7.73 (±0.62)., Conclusion: This study confirms that gas flow is an appropriate method to assess connection leakage. Ankylos Plus connection leakage was very low when the assembly was tightened manually. Among conical connection systems, low (Ankylos Plus) and high (One Morse) leakage was observed. This gas flow study suggests, therefore, that connection design is not the most important parameter for implant/abutment connection leakage.

Purpose: To evaluate the accuracy of Image Tool Software 3.0 (ITS 3.0) to detect marginal microleakage using the stereomicroscope as the validation criterion and ITS 3.0 as the tool under study., Materials and Methods: Class V cavities were prepared at the cementoenamel junction of 61 bovine incisors, and 53 halves of them were used. Using the stereomicroscope, microleakage was classified dichotomously: presence or absence. Next, ITS 3.0 was used to obtain measurements of the microleakage, so that 0.75 was taken as the cut-off point, and values equal to or greater than 0.75 indicated its presence, while values between 0.00 and 0.75 indicated its absence. Sensitivity and specificity were calculated by point and given as 95% confidence interval (95% CI)., Results: The accuracy of the ITS 3.0 was verified with a sensitivity of 0.95 (95% CI: 0.89 to 1.00) and a specificity of 0.92 (95% CI: 0.84 to 0.99)., Conclusion: Digital diagnosis of marginal microleakage using ITS 3.0 was sensitive and specific.

Objectives: To compare microleakage of three self-etch adhesives and to analyze enamel surface morphology and interfacial morphology of resin-enamel and resin-dentin interface under scanning electron microscope (SEM)., Experimental Design: Study was conducted in 65 extracted human premolars. Class V cavities were prepared in 45 teeth and assigned to three groups (n = 15) according to three self-etch adhesives (OptiBond All-in-One, iBond, and Adper Prompt L-Pop). After restoration, 10 samples from each group were used to assess microleakage at enamel and dentin margin. Five samples from each group were used for analysis of interfacial morphology at resin-enamel and resin-dentin interface under SEM. Remaining 20 teeth were used to prepare flat enamel buccal surfaces to analyze the difference in surface morphology after treatment with three adhesives (n = 5 each) and 36% phosphoric acid treatment (n = 5)., Principal Observations: At enamel margin, Prompt L-Pop depicted least leakage of all the three adhesives and also showed best interfacial adaptation under SEM. At dentin margin, OptiBond All-in-One showed significant less leakage than iBond and Prompt L-Pop. On flat enamel surface, phosphoric acid produced the most retentive etching pattern when compared with the three adhesives., Conclusion: Prompt L-Pop showed the best bonding effectiveness in enamel, whereas OptiBond All-in-One performed significantly better in dentin., (Copyright © 2012 Wiley Periodicals, Inc.)

Purpose: This study sought to evaluate the influence of methodologic aspects on variations in the findings of in vitro microleakage studies of the implant-abutment interface., Materials and Methods: The MEDLINE, EMBASE, and Cochrane Library databases were consulted for in vitro studies published between 1990 and August 2011. Date from the studies that met the inclusion and exclusion criteria were arranged in tables and subjected to descriptive analysis., Results: Twenty-one studies were found to be eligible for the analysis after application of the inclusion/exclusion criteria. Sixteen studies used bacteria (76.2%), one used a bacterial toxin (4.76%), one used saliva (4.76%), two employed dyes (9.52%), and one used a combination of dyes and bacteria (4.76%). Eight studies evaluated microleakage from the inner portion of the implant to the external portion (38.1%) and nine examined the reverse (42.85%), while four studies investigated the relationship between them (19.05%). The volume inoculated inside the implants ranged from 0.1 to 5.0 mL. The bacterial concentrations used in the tests ranged from 2.41 x 10⁶ to 8 x 10⁸ colony-forming units/mL. Oral bacterial flora; mixtures of bacteria, toluidine blue, and gentian violet; and lipopolysaccharide of Salmonella enterica bacterial toxins were used. The monitoring period of test results ranged from 24 hours to 11 weeks for bacteria, 5 minutes to 7 days for dye, and 7 days for bacterial toxins. In four studies, microleakage was correlated with the size of the implant-abutment microgap. The external-hexagon implant configuration showed the greatest microleakage, followed by internal-trilobe, internal-hexagon, and internal-taper configurations., Conclusion: The lack of standardization hinderd comparisons of the studies and could explain the divergent results. It is suggested for future studies that special emphasis be placed upon inoculation and analysis of the specific volume for each system, lower concentrations of inoculated bacterial suspensions, and shorter follow-up time when using bacteria.

Background: The authors conducted a study to evaluate the influence of dentin moisture on the degradation of the resin-dentin interface in primary teeth under clinical and laboratory conditions., Methods: The authors prepared 40 Class I restorations (five teeth per group) by using a cylindrical diamond bur, leaving a flat dentin surface on the pulpal floor. They vigorously rubbed two coats of a simplified etch-and-rinse adhesive on either dry or wet demineralized dentin under clinical or laboratory conditions. After performing restorative procedures, the authors extracted teeth prepared under clinical conditions after 20 minutes (immediately) or the teeth exfoliated after six months. The authors also tested the teeth prepared under laboratory conditions immediately or after six months of being stored in water. They sectioned the teeth to obtain resin-dentin bonded specimens for microtensile testing and for silver nitrate uptake (SNU) under scanning electron microscopy. They performed a three-way analysis of variance and Tukey test (α = .05) on the SNU bond strength data., Results: Statistically higher bond strength values (megapascals [standard deviation]) were observed when bonding was performed under laboratory conditions (clinical = 25.2 [3.6] MPa versus laboratory = 28.5 [4.4] MPa; P < .05). Degradation occurred only in the wet dentin groups under both experimental conditions (immediately = 31.3 [4.5] MPa versus after six months = 21.3 [2.1] MPa; P < .05). SNU occurred in all groups and was statistically higher after six months of clinical function or water storage (immediately = 13.9 [4.9 SD] percent versus after six months = 34.1 [4.5 SD] percent; P < .05)., Conclusions: The bonding of adhesives to dry demineralized dentin produces adhesive interfaces that are more resistant to degradation regardless of the bonding condition., Clinical Implications: Resin-dentin bond strengths produced under laboratory conditions in primary teeth may be higher than those obtained under clinical circumstances, although both conditions (clinical and laboratory) seemed to yield similar results. Bonding to dry demineralized primary tooth dentin produced resin-dentin interfaces that were more resistant to degradation.

Background: The aim of this study was to validate the micro-CT and related software against the section method using the stereomicroscope for marginal leakage assessment along the sealant-enamel interface., Methods: Pits and fissures of the occlusal surface of 10 teeth were sealed with a resin-fissure sealant material without acid etching, thermocycled for 5000 cycles, immersed in 50% silver nitrate for three hours and scanned using micro-CT. Teeth were embedded in epoxy resin and cut in three sections. The middle section was subjected to micro-CT and stereomicroscopy. Images were taken from the left and right sides of the sealant-enamel interface at both the left and the right site of the section. Two experienced evaluators assessed marginal leakage., Results: Both assessment instruments observed no leakage in 37 out of the 40 images evaluated. Leakage at the sealant-enamel interface was observed in three stereomicroscopy images only. A fracture line in the sealant was seen on eight stereomicroscopy images and observed in only two micro-CT images., Conclusions: The quality of the micro-CT and related software used in the present study does not qualify it to replace the section method as the gold standard for marginal leakage assessment at the sealant-enamel interface of permanent teeth., (© 2012 Australian Dental Association.)

Background: Dental caries affects populations of all ages in all the regions of the world, with the child patient being at the highest risk. Fifty percent of the permanent molars are decayed by the age of 12, due to lack of information about protection and occlusal morphology. Pit and fissure sealing undoubtedly plays a fundamental role in preventing occlusal caries. The most common approach to assess the sealing ability of pit and fissure sealants of tooth/restoration is the measurement of dye penetration along the interface., Aims and Objectives: The present study aims to evaluate the microleakage and penetration depth of three different types of dental materials, namely (A) Conventional pit and fissure sealant, (B) Flowable composite, (C) Flowable nanocomposite., Study Design: This in-vitro comparative study comprised of extracted human posterior teeth mounted as blocks., Materials and Methods: In the present study, microleakage and penetration depths of conventional sealants/flowable composite and nanocomposite were measured with the help of a dye under stereomicroscope., Statistical Analysis: A student't' test and Analysis of variance (ANOVA) tests were performed to compare the mean microleakage and penetration depth., Results: Microleakage was found to be highest for the flowable composites, and least for the conventional sealant. The nanocomposite values were intermediate. Penetration depth was highest for nanocomposite and least for flowable composite., Conclusions: According to the results, the nanocomposite was found to be an excellent dental material for penetration in deep pits and fissures, though it exhibits mild microleakage. Hence, it can be recommended for use in pediatric dental patients, as a pit and fissure sealing agent.

Aim: To assess the routes of bacterial leakage in a commonly used two-chamber model designed to evaluate root fillings., Methodology: Fifty-one intact human mandibular premolars with fully developed roots were used. They were left completely intact (n=23), or were accessed, instrumented and either left open (n=5) or root filled with gutta-percha and AH Plus (n=23). All teeth were sealed between two chambers using sticky wax. The apical root aspects were left uncovered. The upper chamber was seeded with Enterococcus faecalis. An enterococci-selective broth was used in the lower chamber. Leakage was assessed for 120 days and compared using survival statistics (α<0.05). Subsequently, roots were trans-sected, stained using a 'live' DNA stain (Syto59) and inspected using confocal laser scanning microscopy. An E. faecalis-specific RNA probe was used for fluorescence in situ hybridization (FISH)., Results: Leakage started to occur from day 56, with further occurrence essentially identical between root filled teeth and intact counterparts (P=0.71). All the trans-sections showed fluorescence related to Syto59 between the cementum layer and the sticky wax. Fluorescence was also observed between the root filling and the tubular dentine, whilst it was absent at the interface between root filling and sclerotic dentine. Secondary dentinal tubules, i.e. lateral branches connecting the main counterparts, contained fluorescent material. FISH revealed that Syto59 exclusively stained E. faecalis., Conclusions: The current experimental method proved to be unsuitable to compare root fillings. Histology revealed interesting observations regarding the relationship of dentine structure and bacterial leakage, which warrant further investigation., (© 2011 International Endodontic Journal.)

In spite of its role in the degradation of tooth-biomaterial interfaces, reports on nanoleakage are largely inconsistent. The aim of this work was to assess nanoleakage patterns qualitatively and quantitatively in 3D, to determine the influence of direction, position, and inclination of the field-of-view. Therefore, we applied a gold-standard 3-step etch-and-rinse adhesive to bur-cut dentin surfaces, after which interface samples were sectioned, infiltrated with an ammoniacal silver-nitrate solution, and embedded by common TEM procedures. High-resolution 3D models of interfaces were then generated by FIB and electron tomography, following strict conditions determined by Monte Carlo simulations. Inverted images in FIB tomography disclosed morphological characteristics analogous to those revealed by TEM. Quantitative analysis revealed large variations in silver-nitrate uptake between 2D image projections in different directions. Furthermore, silver-nitrate fractions in individual 2D image projections were seldom related to the total 3D volumetric fraction. Electron tomography showed that inclination also affected the morphology of silver-nitrate patterns. In conclusion, conventional nanoleakage evaluation is heavily influenced by direction, position, and inclination of the field-of-view, and thus may contain artifacts.

Objectives: To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated., Material and Methods: A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled) and three brands of silver nitrate salt (Merck, Synth or Cennabras) at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h) and concentrations (1, 5, 25, 50%) of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25% or 50% AgNO₃ solution and the primary teeth in 5% or 50% AgNO₃ solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (α=5%)., Results: The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9). Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm). In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000)., Conclusions: Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO₃ solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5% concentration, the solutions were capable of indicating loss of marginal seal in the composite restorations; the 3-step conventional adhesive system had better performance regarding microleakage in enamel on primary and permanent teeth.

The aim of the study is to compare the sealing ability of two adhesive systems. Thirty teeth were endodontically treated and were randomly assigned to 2 groups: G 1 - 3-step adhesive (Solobond-Plus) and G 2 - 2-step adhesive (Solobond-M). Posts containing glass fiber were cemented using the adhesive technique recommended by the manufacturer. All samples were mounted on a glucose leakage model. A 10 microL aliquot of solution was drawn from the glass bottle using a micropipette. The samples were then analyzed in a UV-Vis spectrophotometer. The two tested adhesive systems presented a similar capacity to prevent the glucose infiltration.

Objectives: To evaluate and measure the interfacial space or the restoration cavity integrity for probable microleakage using acetate film; acetate peel technique under different magnifications., Study Design: Premolar tooth was obtained and standardized class V restoration with Z-350 done both buccally and lingually. The tooth was hemisectioned buccolingually and embedded in epoxy resin, polished, acid etched, washed and dried. The sectioned sample was flooded with acetone and a pre-cut acetate film placed over it. As the acetone evaporated, the film took the shape of the micro relief produced by etching and dried in 10-15 mins. It was pulled off the tooth surface and mounted between two glass slides for examination under research microscope with different magnifications., Results: This enabled us to measure the interfacial space that might lead to leakage of restoration and also could detect the intricate details of tooth., Conclusion: The acetate peel technique is an efficient way to study the interfacial space/restoration-cavity marginal integrity at a higher magnification and was a fast and reliable tool for assessing the microleakage of a restorative material.

Aim: To evaluate the sealer/dentine interface associated with an epoxy resin sealer using the combination of Goldner's trichrome stain (GTS) and scanning electron microscopy (SEM) to verify the use of the experimental methodology., Methodology: Extracted human maxillary incisors (6) were subjected to root canal treatment. Subsequent to pulp removal, canal instrumentation and smear layer removal using EDTA and NaOCl, teeth were randomly and equally assigned to a 'wet' or 'dry' group. The 'dry' group was desiccated (95% ethanol/suction/paper points/air-drying), whilst the 'wet' group was treated with a saline rinse/suction/single paper point. Canals were then filled with an epoxy-based resin sealer and warm vertical gutta-percha compaction. After 7-day storage at 37°C, roots from each group were sectioned into apical, middle and coronal horizontal subsections that were cut and split into paired halves and evaluated with GTS or SEM. With GTS sections, hybrid layer and sealer tubular penetration were measured (n=15 measurements/intracanal location/condition) and evaluated using a two-factor repeated measures analysis of variance. The SEM qualitative analysis of paired sections was included as a complementary confirmation of GTS analyses., Results: In dry and wet groups, there was no conspicuous sealer/dentine interface hybrid layer, irrespective of canal location. However, dry specimens exhibited more uniform sealer distribution with deeper tubular penetration in the coronal and middle third (P<0.05). In contrast, there was decreased sealer distribution and tubule penetration in the apical third, regardless of moisture condition (P<0.05)., Conclusions: The experimental methodology (combination of GTS and SEM) can be used to evaluate the intracanal resin sealer/dentine interface. The pilot data indicated that thorough drying of the root canal system may result in improved epoxy resin sealer distribution and deeper resin sealer tubular penetration, especially in the coronal and middle thirds of root canals., (© 2010 International Endodontic Journal.)

Purpose: To evaluate the nanoleakage of one- and two-step self-etch adhesives bonded to artificial carious dentin., Methods: Deep dentin of 24 human molars was exposed and divided into four groups. One group served as control while the others were demineralized in artificial demineralization solution for 10 minutes, 6 hours, and 24 hours. Roots were sectioned and the crowns were bonded with one- and two-step self-etch adhesives (Clearfil S3 and Clearfil SE Bond) then restored with flowable composite (Estelite Flow Quick). Specimens were exposed to intrapulpal pressure through a tube connected to a barrel filled with silver nitrate solution in total darkness for 24 hours and then sectioned into two mid-slabs that were photo-developed and prepared for nanoleakage evaluation using FE-SEM and EDX. Penetration of silver into the hybrid and adhesive layers was evaluated and compared between adhesives and dentin condition. Data were statistically analyzed by Kruskal-Wallis test (alpha = .05)., Results: Increasing depths of demineralization were observed with increasing demineralization time. There were statistically significant differences for both adhesives (P < 0.05) and dentin demineralization (P< 0.05) in hybrid and adhesive layers. Normal dentin interfaces revealed no or slight nanoleakage regardless of adhesive. The bonded interface treated with one-step Clearfil S3 showed significant differences between normal and demineralized dentin. Also a trend towards increases in nanoleakage with the increasing of the demineralization time was demonstrated. Different patterns of nanoleakage were observed within adhesives.

Objectives: Our aim was to improve the comprehension of in vitro tracer leakage studies and to determine in which conditions such studies can be reliable. We aimed to develop different theoretical models to describe either an initially dry or a wet interface (slit) between sealer and dentin., Methodology: Equations based on physical laws were derived to model theoretically in vitro tracer penetration. For the dry interfaces, atmospheric, hydrostatic, tracer gravimetric, capillary and internal air pressures were considered as the underlying forces that control tracer penetration. For wet interfaces, the laws of diffusion were used to model colorant penetration., Results: In both cases penetration is influenced by the width of the interface and by the size of the colorant. Calculations for dry conditions have shown that penetration is quick, mainly driven by the capillary pressure, and the penetration increases as the width of the interface diminishes. Dentinal tubules and the extent of their interconnection modify the penetration depth. For wet conditions, tracer size is the main factor controlling the penetration length and speed (the bigger the tracer, the slower the penetration)., Significance: Our model calculations demonstrate that tracer penetration studies have to be performed under strict experimental conditions. Dry and wet interfaces are two extreme cases with very different tracer penetration modes. In vitro colorant penetration tests should be performed in both of these conditions avoiding cases where the slit contains both air and water. Theses models can be adapted to other dental situations as well., (Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

The aim of our study was to evaluate the potential of en face optical coherence tomography (OCT) for the detection of apical microleakage after 980 nm and 1,064 nm laser-assisted endodontic treatment. Ninety, human, single-rooted teeth with one straight root canal and closed apices were used. All roots were prepared biomechanically to the working length at an apical size 30 and 0.06 taper. The teeth were divided into three equal groups of 30 samples each, according to the treatment to be applied to the root canal. Group I received 980 nm diode laser (3 W, 0.01 s on time, 0.01 s off time, 5 s per procedure, four procedures); group II received neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1.5 W, 15 Hz, 5 s per procedure, four procedures). In group III the root canals were approached conventionally only. In all groups the root canal filling was performed with AH Plus endodontic sealer and gutta-percha points. An en face OCT prototype was used for the investigation of apical microleakage. According to one-way analysis of variance (ANOVA) and en face OCT, the number of defects in the laser groups was significantly lower (P < 0.005) than in the control group. No statistical differences were noted between the laser groups (P = 0.049). En face OCT imaging proved that laser-assisted endodontic treatment improved the prognosis of root canal filling and led to a reduction in apical microleakage.

The goal of this in vitro study was to identify the most suitable dye for endodontic dye leakage studies, which could be a further step towards standardisation. The root canals of 70 extracted, single-rooted human adult teeth were enlarged to apical size 50 using hand instruments. The teeth were divided into seven groups (n = 10 each), and all root canals were completely filled by injection with one of the following dyes: methylene blue 0.5% and 5%, blue ink, black ink, eosin 5%, basic fuchsin 0.5% and drawing ink. Transverse root sections from the coronal, middle and apical part of the roots were examined, and the percentage of the dentine penetrated by dye was evaluated by software-supported light microscopy. In addition, the range of particle size of drawing ink particles was evaluated. There were conspicuous differences in the relative dye penetration into the root dentine and the penetration behaviour in the different root sections (two-way ANOVA, both p < 0.0001). One dye (drawing ink) penetrated less into the root dentine compared with all the others (p <0.0001). The particle size of this agent (0.1-2 microm) corresponds best with the size range of a representative selection of 21 species of pathogenic endodontic bacteria. Compared to the other dyes tested, drawing ink appears to be superior for use in endodontic dye leakage studies. The penetration behaviour into the root dentine of all the other dyes tested might be one factor that limits the applicability of these dyes in dye leakage studies.

The aim of this study was to investigate the apical leakage of roots filled by three different gutta-percha techniques: lateral condensation, Tagger's hybrid and E&Q Master. Forty-two extracted single-rooted teeth were used. The coronal part of each tooth was removed and the root received biomechanical preparation using a 60-K file. The roots were randomly divided into three groups according to the technique of filling the root canal: Group I, lateral condensation; Group II, Tagger's hybrid; Group III, E&Q Master. The roots were submitted to dye leakage test with Rhodamine B for 7 days, using vacuum during the initial 30 min. The teeth were sectioned longitudinally and the leakage was measured in a linear fashion from apex to crown. Statistical analysis indicated that lateral condensation and E&Q Master techniques showed lower leakage than Tagger's technique (P = 0.0016). However, statistically no difference was found between lateral condensation and E&Q Master system techniques.

This study sought to investigate apical leakage following three endodontic obturation techniques. Fifty-one recently extracted maxillary and mandibular canines were decoronated at the cementoenamel junction (CEJ) level and a size 10 file was passed to the exit of the apical foramen. Working distance was established 0.5 mm from where the file could be seen exiting the apical foramen. All teeth were instrumented using Brasseler Sequence files to a .06 taper size 40 file at working distance. The teeth were randomly divided into three groups: Group A (lateral condensation of gutta-percha with Roth's 811 Elite sealer), Group B (gutta-percha with GuttaFlow sealer), and Group C (Activ GP gutta-percha cone with Activ GP glass ionomer sealer). Two groups of three teeth served as positive and negative controls. There were no significant differences between Groups A and B; however, Group C was significantly different from Groups A and B.

Introduction: The purpose of this study was to investigate the association between dye and bacterial penetration through interim restorations used during endodontic treatment., Methods: Sixty-four extracted human teeth were used, with 2 teeth each as positive and negative controls. Endodontic access with a mesio-occluso-distal cavity was prepared. Palatal cusps of maxillary molars and buccal cusps of mandibular molars were removed. Cotton was placed over the canals and covered with Cavit. Thirty teeth were restored with Ketac Silver (KS) and 30 with KS reinforced with a stainless steel band (KSSB). Samples were submersed in India ink mixed with brain heart infusion broth containing Streptococcus gordonii. After 3 months of simulated chewing, structural integrity and dye and bacterial penetration were assessed., Results: Positive controls had both dye and bacterial penetration. Negative controls had no dye or bacterial penetration. All KS restorations debonded, whereas 18 KSSB restorations (60%) debonded. KS restorations were 1.67 times more likely to debond than KSSB restorations (Fisher exact test). KS was 1.3 times more likely to have dye penetration than KSSB (Fisher exact test) and 3 times more likely to have bacterial penetration, although not statistically significant (chi(2) test). Overall, 88.3% of specimens had dye penetration, and 20% had bacterial penetration. This 68.3% difference indicated no association between dye and bacterial penetration (exact McNemar test)., Conclusions: Stainless steel bands helped maintain structural integrity of KS restorations under masticatory function. Bands helped prevent dye penetration but not bacterial penetration. There was no association between dye and bacterial penetration.

This study compared the depth of penetration and marginal leakage of filled and unfilled sealants, with and without tooth preparation. One hundred and twenty extracted human third molar teeth that were free of restorations, fluorosis, caries, and sealants were used. After adequate storage and surface debridement, the teeth were randomly divided into four groups of 30 teeth each. In two groups, the occlusal surfaces were left intact, while in the other two groups, the occlusal surfaces were prepared using a diamond bur. Teeth in two groups were sealed with a filled sealant, and an unfilled sealant was used to seal teeth in the other two groups. The sealed teeth were then prepared for marginal leakage, immersed in 5% methylene blue (at 37 degrees C) for 24 hours. Subsequently, buccolingual sections were made and each section was examined for sealant penetration and marginal leakage, using a stereomicroscope. The depth of dye penetration and marginal leakage was evaluated according to a method described by Ovrebo and Raadal. The unfilled sealant placed after tooth preparation showed better enamel fissure penetration and less marginal leakage than the filled sealant.

Objective: To investigate the cervical microleakage in Class II cavities restored with Sonicsys approx ceramic inserts and four resin-based materials., Method and Materials: Forty noncarious and crack-free mandibular third molars were used. These teeth were randomly assigned to four groups each containing 10 teeth. No control group was created. On each tooth, one mesial boxlike cavity was prepared using the active head Sonicsys approx no. 3. The cervical margin of each cavity was in enamel about 1 mm coronal to the cementoenamel junction. According to manufacturer's instructions, the prepared cavities were restored using a Sonicsys approx ceramic inserts no.3 and four resin-based materials as follows: group 1, Tetric Flow; group 2, Admira Flow; group 3, Nexus 2; group 4, X-Flow. After finishing and polishing, all specimens were stored in distilled water for 7 days at 37 degrees C, thermocycled 1,000 cycles between 5 degrees and 55 degrees C, and stored for 24 hours in basic fuchsine 2%. All specimens were then embedded in clear acrylic resin and sectioned along a mesial-distal plane through the middle of the cervical margin. The cervical areas of the resulting sections were examined using an optical microscope to assess the dye penetration. The registered scores were analyzed using Kruskal-Wallis and Mann-Whitney U tests., Results: Microleakage was detected in each experimental group. Kruskal-Wallis test revealed statistically significant differences among groups (P = .009, alpha = .01). The Mann-Whitney U test showed significant differences between Admira Flow group and Tetric Flow (P = .011, alpha = .05), Nexus 2 (P = .001, alpha = .01), and X-Flow (P = .004, alpha = .01), respectively., Conclusion: Within the limitations of this study, the extent of microleakage in the cervical area (enamel) of Class II cavities restored with Sonicsys approx ceramic inserts depends on the material used for luting. The highest leakage occurred when Admira flow was used.

Objective: The use of self-etch adhesives has increased in spite of reports of deficient enamel bonding. Some clinicians etch enamel separately to circumvent this shortfall. Therefore, the objective of this study was to assess the influence of acid-etching on the enamel sealing of 3 self-etch adhesives after thermal fatigue., Method and Materials: Two box-type preparations were restored in each of 30 bovine incisors with 1 of 3 self-etch adhesives: Adper Prompt L-Pop (3M ESPE); Clearfil SE Bond (Kuraray America); or iBond (Heraeus Kulzer), with and without phosphoric acid enamel etching, followed by Filtek Z250 (3M ESPE). After half of the restorations were fatigued for 1,500 thermal cycles, marginal sealing was challenged with 50% ammoniacal silver nitrate. Silver penetration was ranked from 0 to 4 and interfaces analyzed under a field-emission scanning electron microscope (FESEM) with a backscattered detector. Nonparametric statistical analyses were carried out at a 95% confidence level., Results: Clearfil SE Bond resulted in significantly less enamel leakage than the other 2 self-etch adhesives. Acid etching significantly reduced silver infiltration for all adhesives when specimens were thermocycled. When specimens were not thermocycled, acid etching only reduced silver infiltration for iBond. Under the FESEM, silver deposition was observed inside the adhesive layer for Adper Prompt L-Pop and iBond. For Clearfil SE Bond only 2 of 10 specimens displayed silver infiltration along the enamel-adhesive interface., Conclusion: Etching with phosphoric acid improved the enamel marginal sealing of the 3 self-etch adhesives when specimens were subjected to thermal fatigue.

Aim and Design: The requirements of an effective dentin adhesive system include the ability to thoroughly infiltrate the collagen network and partially demineralized zone, to encapsulate the collagen and hydroxyapatite crystallites, to produce a well polymerized durable hybrid layer with high bond strengths. Microleak-age and marginal percolation are the most detrimental factors thwarting the success of any restoration. However the presence of leakage pathways, called nanoleakage have been observed in the hybrid layer, even in the absence of microleakage. The nanoleakage patterns of four dentin adhesives (Prime & Bond NT, AdheSE, Clearfil S3 bond and Fuji Bond LC) was compared using Scanning electron microscopy and Energy Dispersive Spectroscopy, by the silver nitrate penetration method., Results and Conclusion: The results indicated that etch and rinse adhesives showed the maximum nanoleakage followed by the self etch systems. The glass ionomer based bonding agents showed the least nanoleakage. It is extremely important to take nanoleakage as a consideration while choosing dentin adhesives, to ensure success of the restoration.

This study determined the validity of marginal ditching and staining as criteria for the diagnosis of secondary caries around amalgam restorations. One hundred and twenty-four Class I amalgam restorations on extracted human teeth were submitted to standardized clinical examinations. A calibrated examiner recorded the presence of ditching in the tooth/restoration interface, the occurrence of bluish-grey staining on the occlusal surface, and their relationship with the presence and severity of secondary carious lesions. Examinations were repeated after 4 days to calculate the intra-examiner reliability. Stereomicroscopic inspection of the serial tooth sections was used as the gold-standard. Six teeth were lost during the study. Of the 118 remaining teeth, 19 (16%) showed occlusal bluish-grey staining and 26 showed more than 0.20 mm wide marginal ditches. Of the latter, 14 presented narrow ditches (0.20-0.45 mm), while 12 presented wide ditches (0.45 mm). The evaluation criteria presented low sensitivity and positive predictive values. Positive and negative likelihood ratios showed that the criteria exhibited, indistinctly, the same odds to determine a positive or negative result for a diseased or healthy tooth. It was concluded that marginal ditching and staining were not valid criteria for the diagnosis of secondary caries around occlusal amalgam restorations.

The purpose of the present study was to verity whether different conditions of contact with a dye solution would result in different levels of the impregnation by the marker agent in human radicular dentin. The root canals of 60 upper human canines were immersed in methylene blue dye (0.5%, pH 7.0) for 24 h under six different conditions: passive immersion; pre-agitation for 10 min using an endodontic ultrasound; pre-agitation for 10 min using a cleaning ultrasound; 25-mmHg vacuum for 10 min followed by passive immersion; 30-mmHg and 650-mmHg vacuum for 24 h. The roots were longitudinally sectioned and dye impregnation was assessed by a trained and calibrated examiner, using the Q 550 IW image analyser (Leica Qwin, Cambridge, England). The measurements were analysed with anova and Tukey test. The results revealed no significant difference among the different methods for dye impregnation. In the cervical third, impregnation with 30 mmHg was significantly more effective than with endodontic ultrasound or 25 mmHg. At the apical third, no differences were observed between any of the dye impregnation methods. The comparison of different thirds revealed a statistically significant difference between the cervical and apical and the middle and apical thirds, but not between the cervical and middle thirds.

Aim: To evaluate the reactivity of different endodontic materials and sealers with glucose and to asses the reliability of the glucose leakage model in measuring penetration of glucose through these materials., Methodology: Ten uniform discs (radius 5 mm, thickness 2 mm) were made of each of the following materials: Portland cement, MTA (grey and white), sealer 26, calcium sulphate, calcium hydroxide [Ca(OH)(2)], AH26,Epiphany, Resilon, gutta-percha and dentine. After storing the discs for 1 week at 37 degrees C and humid conditions, they were immersed in 0.2 mg mL(-1) glucose solution in a test tube. The concentration of glucose was evaluated using an enzymatic reaction after 1 week. Statistical analysis was performed with the anova and Dunnett tests at a significant level of P < 0.05., Results: Portland cement, MTA, Ca(OH)(2) and sealer 26 reduced the concentration in the test tube of glucose significantly after 1 week (P < 0.05). Calcium sulphate reduced the concentration of glucose, but the difference in concentrations was not significant (P = 0.054)., Conclusions: Portland cement, MTA, Ca(OH)(2) and sealer 26 react with a 0.2 mg mL(-1) glucose solution. Therefore, these materials should not be evaluated for sealing ability with the glucose leakage model.