Introduction: Several materials are recommended for retro filling. One of the best materials that have ever been suggested is MTA (Mineral Tioxide Aggregate). Many studies have confirmed the biocompatibility, proper marginal adaptation and salability of this agent. The purpose of this study was the evaluation of apical evaluation of apical Microleakge in cavity preparation with different dimension for retrograde.Materials & Methods: In this study, we examined the influence of cavity dimension on salability of MTA. We selected sixty roots with a single canal. After cleaning and shaping, the canals were obturated with guta-percha and canal sealer by lateral condensation technique.Samples were divided into 5 groups: two positive and negative control groups and three experimental groups. Cavity preparation was performed for all experimental groups with the following methods:A: 1.5mmdepth and 0.6mm widthB: 3mm depth and 0.6mm widthC: 3mm depth and 1.5mmwidthAfter cavity preparation, MTA powder was placed in each cavity and wet cotton adjacent to them for 24 hours. Then the samples were placed in Incubator (37°C and 100% wet) for 72 hours.Subsequently dye penetration examination was performed; dye leakage was measured by stereomicroscope. We used T-test for statistical analysis.Results: After statistical analysis these results were achieved:1. Increase depth from 1.5mm to 3mm reduce the amount of leakage.2. No significant difference between leakage of cavities with different width was found (P-value>0.05).Conclusion: It's better to prepare cavities for retrograde filling with more depth and less width.

Background and Aims: Using the conservative adhesive resin restoration (CAR) in uncooperative children lead to numerous problems because of being time consuming. The purpose of this study was to compare the microleakage of conservative adhesive resin restoration under separate curing and co-curing.Materials and Methods: In this experimental study, 120 intact premolar teeth were collected and 120 vertical grooves were prepared on them. Then the teeth were divided into four groups: group 1, separated curing of bonding agent, flowable composite and sealant; group 2, co-curing of all materials for 60 seconds; group 3, co-curing of all materials for 40 seconds and group 4, co-curing of all materials for 20 seconds. Then the specimens were thermocycled and immersed in basic fuchsin solution. The teeth were sectioned horizontally and dye penetration was evaluated with stereomicroscope. Dates were analyzed using one-way ANOVA and Scheffe test.Results: Mean value of dye penetration in groups 1, 2, 3, and 4 was 1.53±0.6, 2.06±0.6, 2.5±0.7 and 3.53±0.6, respectively. There was a statistically significant difference between group 1 and the other groups (P=0.0001).Conclusion: Considering the problems caused by microleakage in conservative resin adhesive restorations, cocuring method should not be used. In the case of using co-curing method, 60 second curing time is suggested for sufficient polymerization.

Backgroud and Aim: Microleakge is one of the most common cause of failure in restorative dentistry in this study the Microleakge of filtek p90, filtek p60 was evaluated and compared. Materials and Methods: In this experimental study, on 48 premolar teeth standardized class II MOD preparations were made cervical margin of mesial preparation were 1mm above the CEJ and 1 mm and the distal preparation were 1 mm below the CEJ Samples divided in to 3 groups of sixteen teeth. A group: teeth were filled with filtek silorane (3M ESPE, USA) and silorane system adhesive self-etch primer and bond. B: teeth were filled with filtek silorane and Adper single bond plus. C: sixteen teeth were filled with filtek p60 and Adper single bond plus. After AgNO3 dye opplicaiton microleakage were evaluated by stereomicroscope. data were statistically analyzed by kurskal-wallis and Wilcoxon. the level of 0. 05 considered significant. Results: The most enamel microleakage was related to C and lowest enamel Microleakge was shown in A group. The most dentin microleakage was related to B and the lowest dentin Microleakge was shown in A group. Microleakage was significantly different between A, with B and C (P‹ 0. 05) dentin microleakage was not significant difference between B and C. Conclusion: Type of composite and bonding effect to microleakage, the lowest microleakage was gingival margine irrespective of the location of the margine related to group A.

Introduction: The purpose of this in vitro study was to compare the Microleakge rate of class V compoglass-F and Fuji II LC restorations.Materials & Methods: Sixty class V cavity preparations with occlusal margins in enamel and gingival margins in cementum were prepared on the buccal and lingual surfaces of 30 extracted human premolar teeth. The teeth were divided randomly into 2 treatment groups. Group 1 was restored with Fuji II LC and group 2 with compoglass-F. After treatment, the samples were stored in tap water for 24 hours, then thermocycled, stained with dye, and finally scored for Microleakge. The Mann-Whitney analysis of variance was done for data analysis (a=0.05). Results: The Fuji II LC had a higher degree of Microleakge in occlusal and occlusal plus axial walls compared with compoglass (P=0.000). Where as, compoglass had microleakag in gingival and gingival plus axial walls (P=0.0003).Conclusion: The results revealed that Fuji II LC had less microleakage in the gingival margin in which enamel does not exist. Where as microleakage of compoglass restorations was significantly less than Fuji II LC in the occlusal wall where enamel exists.

Background and Aim: There is a need for a material with high sealing ability to prevent bacterial and tissue secretions penetration in endodontic surgery. The aim of this study was to compare the microleakage of amalgam and MTA filling materials.Materials and Methods: Thirty-two single-rooted extracted human teeth were collected.Each tooth was apically resected and retroprepared to 3mm depth. Teeth were divided randomly into two groups of 13 teeth each. First group was retrofilled with amalgam and second group with MTA. All root surfaces, except the ending part, were covered with layers of nail polish. Following immersion in 2% methylene blue for 48 hours, the roots were sectioned and the depth of dye penetration was evaluated by computerized scanning and photoshop software. Results were evaluated by t-test.Results: It was shown that MTA Microleakge was significantly less than that of amalgam.The mean dye penetrations of MTA and amalgam were 1.75mm and 3mm, respectively (pv=0.0001).Conclusion: The findings of the present study confirm the proper sealing ability of MTA.

Background and Aim: This study assessed cervical microleakage between a Ni-Cr alloy and 3 indirect polymeric veneering materials.Methods & Materials: In this experimental study, twenty one metalic frameworks (copings) were obtained by fabrication 0.5 mm calibrated wax patterns on a master cast abutment. The wax patterns were provided with 0.4 mm beaded retention on the veneering surfaces and cast in a Ni-Cr based alloy used for fixed partial dentures. The Ni-Cr copings were divided equally into 3 groups, 7 samples in each group, and veneered with 3 polymeric materials (Belleglass, Signum, Gradia). Three chemical conditioning systems (metal prep, retention flow, GC metal primer 11) were used with the respective veneering system recommended by the manufacturer; no control group was created.After, 2 weeks of storage in distilled water at 37oC, 2000 cycles at 5-55oC, and 24 hours of storage in 0.5% basic fuchsine, specimens were embedded in clear liquid casting resin and sectioned along a perpendicular cervico-incisal plane through the middle of cervical collar. The surfaces of the resulting sections were examined in the cervical area with a dimensional microscope to detect dye penetration. Scores were compared and analysed with the use of Kruskal-wallis test.Result: Signum was associated with the highest microleakage scores (1.4286 0.5345) and the least micro leakage at the interface was produced by Belleglass (0.4236 0.07868), followed by Gradia (0.8571 0.3779). Only the difference between Belleglass and Signum was significant (P=0.024).Conclusion: Within the limitation of this in vitro study, the extent of cervical Microleakge between the coping and veneer depended on the particular polymeric material used for veneering. The extremes of the study were Belleglass and Signum (respectively lowest and highest leakage scores).

Introduction: The purpose of this in vitro study was to investigate coronal microleakage in anterior weakend teeth after root canal therapy, reinforced with different tooth-coloured material and FRC post.Methods and Materials: A total 48 extracted intact central incisors were randomly divided into four experimental groups (n=12). All specimens were endodontically treated using lateral condensation and crowns were totally removed from 2mm of CEJ and were over flared to simulate weakened teeth . Control group (group I) was restored only with gutta percha .In other groups root canal walls were prepared (etching, washing and gentle drying, bonding) and the surface of the posts were cleaned with alcohol and after that covered with bonding agent and then light  polymerized for 40 seconds. Finally post cementation was done during reinforcing of weakened root canal walls with packable composite in group II, self-cure composite in group III and dual cure composite in group IV. All specimens were thermocycled for 500 cycles between 5oc and 55oc0 with a dowel time of 20 seconds before immersion in dye. Then all specimens were sealed with sticky wax and coated with two layer of nail polish & then they were placed in 0.5% fuschine for 24 hours at room temperature and were sectioned longitudinally from the center of post with tooth cutter. Dye penetration in both sections of each tooth were evaluated using a stereomicroscope equipped with digital camera at original magnification of 32× and microleakage recorded in mm. One-way analysis of variances (ANOVA) and least square difference were used for statistical analysis.Result: The control group showed the maximum microleakage and the minimum was related to the third group .There was a significant difference among the average microleakage of all groups.Conclusion: Combination of FRC post and tooth-coloured materials did reinforce structurally compromised root and decreased microleakage and also the microleakage of root/bonding material is more than post/tooth-colored material. Microleakge in selfcure Group because of its polymerization was the least.

Background and Aim: Although the use of adhesive systems can be effective in decreasing Microleakge, it is still a major problem in composite resin restorations. The aim of the present study was to evaluate the marginal sealing ability of resin composite restorations using four dentin bonding systems in both primary and permanent teeth. Materials and Methods: In this experimental study, one hundred and sixty extracted human teeth (80 primary and 80 permanent) were selected. All of the samples received a class V cavity preparation on the buccal surfaces (The coronal half in enamel and the gingival half in cementum or dentin). Each group was then divided into four subgroups each containing 20 teeth. Four different dentin bonding systems (Scotchbond Multipurpose, Single Bond, Clearfil SE Bond and Prompt L- Pop) were used in each subgroup. Then the cavities were filled with composite resin (Z100 for SBMP and Clearfil AP-X for Clearfil SE Bond). Samples were thermocycled, immersed in 0.5% basic fuschin, cut faciolingually and evaluated for dye penetration using a binocular stereomicroscope. Kruskal-Wallis and Dunn tests were used for comparison of microleakage between groups with p<0.05 as the limit of significance. Results: The results showed that: There was significant difference in microleakage among four adhesive systems in both incisal and gingival margins of permanent teeth and in incisal margin of primary teeth (P=0.000, P=0.002, P=0.000 respectively). There was no significant difference in microleakage of restorations with each of four systems between permanent and primary teeth in both incisal and gingival margins except for PLP, which showed a significant different microleakage in the cervical margins (P=0.009). PLP showed better cervical seal in primary teeth compared to permanent teeth. Clearfil SE Bond showed acceptable results at incisal and cervical margins in primary teeth in comparison to other bonding systems. Conclusion: Based on the results of this study, CSEB, SB and SBMP systems showed acceptable clinical results in primary and permanent teeth. Only PLP showed weak results in reducing microleakage. CSEB can be used successfully in primary teeth because of simplicity and reducing leakage in primary dentin and enamel.