Aim : To evaluate the effect of surface moisture on dentinal tensile bond strength. Materials and Methods : Forty freshly extracted caries free, unrestored human mandibular molars were selected. The occlusal surfaces of each tooth were ground to prepare flat dentin surfaces at a depth of 1.5 mm. Following acid etching with 37% phosphoric acid for 15 sec, they were randomly grouped, with ten specimens in each: Group I - Over wet, Group II - Blot dry, Group III- One second dry, Group IV- Over dry. Each group was treated with a single bond adhesive system (3M ESPE) as per manufacturer's instructions. Blocks or cylinders of composite resin were built up using Teflon mould and cured. Tensile bond strengths were tested using Instron universal testing machine. The results were statistically analyzed. Results : The mean tensile bond strength values of group II, Blot dry was highest and statistically significant (P<0.001). Conclusion : After acid etching and rinsing blot drying provided consistently better bond strength.

Aims/objectives : To evaluate in vitro the ultrasonic vibration efficacy with and without water spray cooling on the reduction of the amount of force necessary to dislodge the cast posts cemented with resin cement and to compare it with those cemented with GIC Type I luting cement. Materials and Methods : Sixty samples were divided into six groups: groups 1, 2, 3, posts cemented with GIC; groups 4, 5, 6, posts cemented with resin; groups 1 and 4 (controls), no ultrasound; groups 2 and 5, ultrasound without water spray; and groups 3 and 6, ultrasound with water spray. Instron testing machine was used to dislodge the posts from the root canals and the data was statistically analyzed. Results : Ultrasound with water spray (group 3) among the GIC groups reduced the traction force necessary to extract posts by 53.33% whereas ultrasound without water spray (group 5) among the resin groups reduced by 59.5% compared to control. Conclusion: Ultrasound with water is more effective in removing posts cemented with GIC because of the ultrasonic energy being transferred to the post. Ultasonics without water is more effective in removing posts fixed with resin cement probably by the indirect action of heat production.

Aims : To compare the fracture resistance and primary mode of failure of three different pre- fabricated posts like stainless steel, carbon fiber and ceramic posts in endodontically treated crowned permanent maxillary central incisors. Materials and Methods : Root canal treatment was performed on all 30 maxillary central incisors. Post space was prepared and samples were divided into three groups of 10 each. The teeth were inserted with pre-fabricated stainless steel, carbon fiber and ceramic post and cemented using adhesive resins, core fabricated and crowns placed. Mode of failure was carried out by immersing the teeth in black ink for 12 h and then sectioning them mesio-distally. Fracture above the embedded resin was considered favorable and fracture below the resin level was considered unfavorable. Statistical Analysis : Fracture strength was measured using a universal testing machine. Data were evaluated statistically using the Kruskal Wallis test and the Mann Whitney " U"-test. Mode of failure was evaluated statistically using the chi-square test. Results : There was a statistically significant difference showing that the stainless steel post had a better fracture resistance when compared with the other two posts and the carbon fiber showed a statistically more favorable fracture when compared with the other two posts. Conclusions : Within the limitations of this study, it can be concluded that the pre-fabricated stainless steel post exhibited a significantly higher fracture resistance at failure when compared with the carbon fiber post and the ceramic post. The mode of failure of the carbon fiber post was more favorable to the remaining tooth structure when compared with the pre-fabricated stainless steel post and the ceramic post.

Aims and Objective : The purpose of this study is to measure the initial pH of various commonly used beverages and to determine their ability to maintain a low pH by measuring their buffering capacities. Materials and Methods : Twelve commercially available drinks were taken and divided into four groups (preserved fruit juices, tea, mineral water and carbonated drinks. Each group comprised of three drinks. Their initial pH were measured with pH meter and their buffering capacities were measured by adding 1M NaOH in the increments of 0.2 ml into 100 ml of each drink till the pH raised to 5.5 and 7 respectively. Statistical Analysis : The volume of NaOH required to raise the pH to 5.5 and 7 were recorded in all the groups. This data was subjected to statistical analysis using Mann- Whitney tests. Results : Total titratable acidity measurement shows that among all the drinks, there was no significant difference between carbonated drinks and preserved fruit juices while a significant difference was present between carbonated drinks, preserved fruit juices and tea. Conclusion : In this in vitro study, it was found that packaged apple juice had the most buffering capacity with maximum erosive potential whereas green tea had the least.

Aims/Objectives : This in vitro study was designed to measure and compare the temperature rise in the pulp chamber with different light curing units. Materials and Methods : The study was done in two settings-in-vitro and in-vivo simulation. In in-vitro setting, 3mm and 6mm acrylic spacers with 4mm tip diameter thermocouple was used and six groups were formed according to the light curing source- 3 Quartz-Tungsten-Halogen (QTH) units and 3 Light-Emitting-Diode (LED) units. For the LED units, three modes of curing like pulse-cure mode, fast mode and ramp mode were used. For in-vivo simulation, 12 caries free human third molar tooth with fused root were used. K-type thermocouple with 1 mm tip diameter was used. Occlusal cavity was prepared, etched, rinsed with water and blot dried; bonding agent was applied and incremental curing of composite was done. Thermal emission for each light curing agent was noted. Results : Temperature rise was very minimal in LED light cure units than in QTH light cure units in both the settings. Temperature rise was minimal at 6mm distance when compared to 3 mm distance. Among the various modes, fast mode produces the less temperature rise. Temperature rise in all the light curing units was well within the normal range of pulpal physiology. Conclusion : Temperature rise caused due to light curing units does not result in irreversible pulpal damage.

Objectives : The purpose of this study was to determine the microleakage in the 5 ^th and 6 ^th generation bonding agents with that compared with the newly introduced 7 ^th generation bonding agents using three bonding agents. Materials and Methods : A total of 50 recently extracted human upper premolars were subjected to the study. Class V cavity preparations were prepared on the buccal and lingual surfaces of the extracted premolars with occlusal margins in the enamel and gingival margins in the cementum/dentin. The teeth were divided into five groups of 10 teeth each and 20 cavity preparations per group. In the experimental groups, cavities were treated with Single-Bond, Adper Prompt, i-Bond, Clearfil S3, and G-Bond as the dentin bonding agents. After the application of the dentin bonding agents, the cavity preparations were restored with resin composite (Clearfil APX). The specimens were thermocycled, stained with methylene blue dye, and sectioned to evaluate the dye penetration. Data were analyzed using the one-way ANOVA test (Kruskal-Wallis) and Dunn's procedure for pairwise comparison of the data. Results : This study showed that at the coronal margin and the apical margins, the preparations treated with Clearfil S3 showed significantly less leakage than the other groups. Enamel margins provided better marginal sealing than dentin/cementum margins. Interpretation and Conclusion : The study demonstrated that Clearfil S3 bond had a better sealing ability at both coronal (enamel) and apical (dentin/cementum) margins compared with the other dentin bonding agents used.

Aim : The purpose of this in vitro investigation was to evaluate the influence of double application and application of hydrophobic layer on marginal adaptation of four self-etch adhesive systems (XENOIII, ALLBONDSE, CLEARFIL SE TRI BOND, FUTURA BOND). Materials and Methods : One hundred and twenty class V cavities were prepared on intact, extracted human premolars and were divided into three groups of ten teeth each for all four adhesives. Group 1: Application of bonding agents as per manufacturer directions. Group 2: Double application of bonding agents. Group 3: Application of hydrophobic layer. The specimens were restored with composite and light cured. After thermocycling and immersion in 2% Basic Fuchsin dye solution, the teeth were sectioned and dye penetration was observed under a stereomicroscope at 20× magnification. All the samples were scored and results were analyzed using Kruskal-Wallis and Mann-Whitney tests. Results : Group 3, in which the adhesive systems were coated with hydrophobic layer, showed significantly decreased microleakage, followed by Group 1 and Group 2 for all the adhesive systems. And there is no significant different between Group 1 and Group 2. Conclusion : Marginal permeability of one-step adhesives can be minimized by the application of more hydrophobic resin layer, and the double application of one-step self-etch system can be safely performed without jeopardizing the performance of adhesives.

Aim : To compare the fracture toughness and wear resistance of indirect composites cured by conventional post curing methods and electron beam irradiation. Materials and Methods : Forty specimens were randomly assigned into four groups of ten each and were subjected to various post curing methods. Fracture toughness and wear resistance tests were performed and the results were tabulated and analyzed statistically using Kruskal Wallis and Mann-Whitney U test. Results : It was found that Inlay system showed higher values followed by electron beam irradiation. Conclusion : Electron beam irradiation of dental composites gives comparable mechanical properties to other post curing systems. It can be concluded that further studies with increased radiation dose should be performed to improve the mechanical properties of indirect composites.

Introduction : The purpose of this study was to investigate root canal morphology of maxillary second premolars in an Indian population. Materials and Methods : Two hundred maxillary second premolars were collected, stained, decalcified, and cleared. Cleared teeth were examined in a steromicroscope under 7.5× magnification and the following observations were made: (1) length of the teeth, (2) number of root canals, (3) root canal configuration by Vertucci's classification, (4)number of isthmi between the canals, (5) frequency of apical deltas. Results : Of the two hundred maxillary second premolars, 64.1% had one root canal at the apex and 35.4 % had two root canals at the apex. The average length of the teeth was 21.5 mm. Concerning the canal morphology, 33.6% of the teeth exhibited Vertucci type II configuration followed by type IV pattern (31.1%); 29.2% of the teeth possessed type I pattern. An additional canal configuration type XIX was found in one tooth. Isthmi and apical deltas was found in 19% and 14% of the cases, respectively. Conclusion : The root canal morphology of Maxillary second premolars can be complex and requires careful evaluation prior to endodontic therapy.

Aim : Our study aimed to analyze the microleakage of silorane-based composite in comparison to two homologous methacrylate-based composites. Materials and Methods : Standardized class I cavities (4 × 2.5 × 3 mm) were prepared on extracted human premolars and randomly assigned into three groups (N = 15) as follows: Group A, Filtek P90 (silorane) with its dedicated adhesive system (P90 system adhesive); Group B, Adper SE Plus with Filtek Z250; Group C, Peak SE with Amelogen Plus. The teeth were subjected to thermocycling regime (200×, 5-55°C) and dye penetration of tooth sections were evaluated following 30 minute immersion in 2% Methylene Blue dye. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney U test at 95% significance level. Results : Silorane exhibited significantly decreased microleakage compared with any other resin based composite (RBC). The cavities restored with Amelogen Plus displayed nonsignificantly higher microleakage than with Filtek Z250. Conclusion : Although all of the restorative systems had microleakage, silorane technology showed less microleakage comparable to clinically successful methacrylate-based composite. This will improve the clinical performance and extend the composite durability.

This case describes a furcal perforation in a mandibular first molar accompanied by furcal lesion which has been managed after one month. Root canal treatment was performed; subsequently, the defect was repaired with calcium enriched mixture (CEM) cement. The endodontically treated tooth was restored with amalgam. A 24-month recall showed no evidence of periodontal breakdown, no symptoms, in addition to completes healing of furcal lesion. According to physical and biological properties of the newly introduced CEM cement, this novel material may be suitable for sealing and repairing the perforations. The present case report supports this hypothesis.

Treatment of maxillary incisor with an associated cystic lesion by conventional endodontic therapy combined with decompression is reported. Although small cystic lesions frequently heal simply with endodontic therapy, larger lesions may need additional treatment. In some cases, when surgical enucleation is elected, there is a chance for inadvertent injury to adjacent teeth or structures even though periapical surgery has a role in endodontics. Therefore a more conservative approach of decompression and a workable protocol for this was attempted with success and is presented here.

Maxillary first molar can have a mesio-buccal-2 (MB2) orifice located palatally, but adjacent to the mesio buccal orifice. An awareness and understanding of this root canal morphology can contribute to the successful outcome of root canal treatment. This report discusses endodontic treatment of a maxillary first molar with unusual location of second mesio buccal orifice. Conventional diagnostic aids such as radiographs play an important role in assessment of complex root canal morphologies. These modalities, however, do not provide detailed information of the complexity as a result of their inherent limitations. This article discusses the variations in the orifice location and the use of latest adjuncts in successfully diagnosing and negotiating them.