Introduction: The main objective of a root canal sealer is to provide a fluid tight seal. The purpose of this systematic meta-analysis was to determine the relative toxicity of commonly used root canal sealers like zinc oxide eugenol, calcium hydroxide, and resin-based sealers. Materials and Methods: An online search was conducted in peer-reviewed journals listed in PubMed, Cochrane, EBSCO, and IndMed databases between 2000 and 2012). Statistical analysis was carried out by using analysis of variance (ANOVA) followed by post-hoc comparison by Bonferroni method. The comparison between toxicity at 24 h and between 3 and 7 days was done by using paired t-test for each sealer. Results: At 24 h, the relative biotoxicity of the three sealers reported was insignificant (P - value 0.29), but the difference in toxicity was found significant (P < 0.001) after 3 days. Conclusion: Calcium hydroxide sealer and zinc oxide eugenol were found to be significantly biotoxic as compared to resin-based sealers after 3 days.

Aim: The present ex vivo study aimed to evaluate the debris extrusion after instrumenting the root canals by three different files systems. Materials and Methods: Sixty extracted human mandibular premolars with single canals were selected and randomly divided into three groups (n = 20) for instrumentation with three different files. Group 1: WaveOne (primary) single reciprocating file (WO; Dentsply Maillefer, Ballaigues, Switzerland) (25/08), Group 2: Self-adjusting file (SAF; ReDent-Nova, Ra'anana, Israel) (1.5 mm), and Group 3: ProTaper NEXT X1 and X2 (PTN; Dentsply Tulsa Dental, Tulsa, OK) (25/06). Debris extruding by instrumentation were collected into pre-weighed Eppendorf tubes. These tubes were then stored in an incubator at 70^΀ C for 5 days. The tubes were then weighed to obtain the final weight, with the extruded debris. Statistical analysis for the debris extruded apically was performed using one-way analysis of variance and post hoc Tukey's test. Results: The statistical analysis showed a significant difference between all the three groups tested (P < 0.01). The following post hoc Tukey's test confirmed that Group 2 (SAF) exhibited significantly least (P < 0.01) debris extrusion between the three groups tested. Conclusions: The SAF resulted in significantly less extrusion of debris when compared to reciprocating WO and rotary PTN.

Aim: The purpose of the study is to evaluate and compare the biological and chemical-physical properties of four different root-end filling materials. Materials and Methods: Cytotoxicity towards murine odontoblasts cells (MDPC-23) was evaluated using the Transwell insert methodology by Alamar blue test. Streptococcus salivarius, S. sanguis, and S. mutans strains were selected to evaluate the antimicrobial activity by agar disc diffusion test. Solubility was determined after 24 h and 2 months. pH values were measured after 3 and 24 h. To evaluate radiopacity, all materials were scanned on a GE Healthcare Lunar Prodigy. Results: Excellent percentage of vitality were obtained by mineral trioxide aggregate (MTA)-based materials and Biodentine. MTA-Angelus, ProRoot MTA, and Intermediate Restorative Material (IRM) showed the highest values for the inhibition zones when tested for S. mutans, while Biodentine showed the largest inhibition zone when tested for S. sanguis. All the materials fulfilled the requirements of the International Standard 6876, demonstrating low solubility with a weight loss of less than 3%. No significant reduction in pH value was demonstrated after 24 h. ProRoot MTA and MTA-Angelus showed the highest values of radiographic density. Conclusions: The differences showed by the root-end filling materials tested do not cover completely the ideal clinical requests.

Objective: To compare stress distribution in a tooth restored with metal and fiber posts of varying diameters (1.2 and 1.4 mm) by means of three-dimensional finite element analysis (3D-FEA). Materials and Methods: Four 3D-FEA models were constructed: (1) fiber post (1.2 and 1.4 mm) and (2) metal post (1.2 and 1.4 mm). The material properties were assigned and a force of 100 N was applied at 45° angle to the longitudinal axis of the tooth onto the palatal surface incisal to the cingulum. Analysis was run and stress distribution pattern was studied. Results: Maximum stresses in the radicular tooth structure for fiber post were higher than that for metal post. In the former models, stresses in the tooth structure were slightly reduced with increase in fiber post diameter. Conclusions: To reduce stress in the remaining radicular tooth structure, it is better to use a fiber post of a large diameter.

Context: Calcium oxide (CaO) may be added to mineral trioxide aggregate (MTA) or Portland cement (PC) to improve physicochemical and biological properties. Aims: To evaluate the physicochemical properties of PC associated with radiopacifiers and CaO. Materials and Methods: MTA Angelus, PC + 30% zirconium oxide (Zr), or 30% niobium oxide (Nb) associated with 10 or 20% of CaO were evaluated. Gilmore needles were used to evaluate initial and final setting time. Compressive strength was evaluated after the periods of 24 hours and 21 days. pH was analyzed after 3, 12, 24 hours, 7, 14, 21 days. Solubility and flow tests were performed based on the ISO 6876. The data obtained were submitted to analysis of variance and Tukey tests (P ≤ 0.05). Results: The associations with 10% CaO showed greater strength that the associations with 20% CaO. The shortest initial setting time was observed for the association PC + Zr + 20% CaO and MTA. All the cements presented alkaline pH. The flow of all cements was similar. The highest solubility was found in the associations with 20% CaO. Conclusion: The addition of CaO to PC favored the alkaline property and the PC + Zr + 20% CaO presented setting time similar to MTA.

Background: Achieving a good apical seal for root canals is known to be associated with good mineral trioxide aggregate (MTA) adaptation to dentin. Aims: This study aims to compare the marginal adaptation of MTA with root dentin between orthograde and retrograde application techniques using microcomputed tomography (micro-CT) analysis. Settings and Design: Fifty-two single-rooted human teeth were divided into four equal groups: (Group 1) Retrograde MTA (RMTA), (Group 2) Orthograde MTA (OMTA), (Group 3) Etched RMTA (ERMTA), and (Group 4) Etched OMTA (EOMTA). Materials and Methods: For Group 1, 3-mm retrograde cavities were prepared and filled with MTA. For Group 2, the apical 6 mm of the canals were filled with MTA and sealed with sealer cement and warm gutta-percha. In Groups 3 and 4, canals were treated the same as Groups 1 and 2, respectively, except that before placing the MTA, canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA). After 48 hours, all the teeth were analyzed using a micro-CT scanner. Statistical Analysis: Mean dentin-MTA contact and the mean length and width of each gap was analysed using one-way analysis of variance (ANOVA). Statistical significance was set at an α level of 5%. Results: No significant difference in gap volumes was observed in the dentin-MTA adaptation in both orthograde and retrograde application techniques. However, significant difference in the gap volumes was observed between RMTA and ERMTA (P = 0.045). Etching significantly improved the MTA-Dentin adaptation (P < 0.05). The type of application technique did not significantly improve the dentin-MTA adaptation, instead with the use of 17% EDTA, a significant improvement could be achieved. Conclusion: Within the limitations of the present study, it concludes that MTA adaptation to dentin tooth structure is not significantly different between an orthograde and retrograde approach. However, the use of EDTA significantly improved the MTA-Dentin adaptation.

Aim: The aim of this study was to evaluate the microhardness of two composite resins when subjected to three different temperatures and three different light-curing times. Materials and Methods: Two composites were used; Filtek Z250 and Grandio. Three different temperatures (23, 37, and 55 ^o C) were used, utilizing a composite warmer. The heated samples were immediately injected into cylindrical molds (6 mm × 2 mm) and the top surface of the specimens was polymerized for 10, 20, and 40 sec, using a Quartz-Tungsten-Halogen light-curing unit (QTH LCU). Vickers microhardness measurements were performed from both the top and bottom surface of the specimens, following dry storage for 24 hours in the dark. Statistical analysis were performed using one-way analysis of variance (ANOVA) and Tukey post-hoc test at a level of significance of a = 0.05. Results: The results indicated that there was an increase in microhardness as the temperature of the composite was increased for either the top or the bottom surface (P < 0.05). Furthermore, there was a general increase in microhardness for both composites as curing time increased (P < 0.05). The type of composites did not influence the surface microhardness (P > 0.05). Conclusions: Temperature of composites affects their surface microhardness. Also, light-curing time influence microhardness values of the composites tested.

Aim: To compare the effect of three root canal sealer activation techniques on percentage and depth of sealer penetration of MTA Fillapex and AH Plus sealers. Materials and Methods: Sixty teeth prepared till F5 ProTaper size were divided into three equal groups on the basis of sealer activation technique (G1: Ultrasonics, G2: Lentulo spiral, and G3: Counter-clockwise rotary motion). Each group was further divided into two equal subgroups on the basis of type of sealer used: AH Plus (Denstply, Konstanz, Germany) or MTA Fillapex (Angelus, Londrina, PR, Brazil) and obturated with gutta-percha. Horizontal sections at 3 and 6 mm from the apex were obtained and the percentage and depth of penetration of sealers into dentinal tubules were measured using confocal laser scanning microscopy (CLSM). Statistical analysis was performed utilizing Kruskal-Wallis and Mann-Whitney U tests with a significance level of 5%. Results: G1 showed significantly (P < 0.001) high percentage and depth of sealer penetration than G2 and G3 while the difference was insignificant (P > 0.05) between G2 and G3. Conclusion: Percentage and depth of sealer penetration are influenced by the type of sealer used sealer activation technique and by the root canal level. Ultrasonic method of sealer activation and MTA Fillapex showed the best results.

Aims: To evaluate and compare the push-out bond strength of root filled with Endosequence BC, AH Plus and Endomethasone N sealers using lateral condensation and thermoplasticized technique. Materials and Methods: Thirty mandibular premolars with completely formed roots were selected. Teeth were decoronated, working length was determined. Instrumentation and irrigation were performed. Teeth were then obturated with Group 1-Cold lateral compaction (n = 15) or Group 2-Thermoplasticized technique (n = 15). Each group was again subdivided into three depending on the sealers used. Teeth in each subgroup were then sectioned perpendicularly to the long axis to obtain a disc of 2 mm each, which were then subjected to micro push-out test. Data was analyzed with ANOVA. Results: AH Plus sealer in Group 1 showed the maximum (4.77 ± 1.67 MPa) push-out bond strength among the three sealers and between two groups. The mean strength of Bioceramic sealer was lower in Group 1 (2.62 ± 0.76 MPa) and higher in Group 2 (3.52 ± 0.69 MPa). Conclusions: The push-out bond strength of Endosequence BC sealer was lower than the AH Plus root canal sealer with cold lateral condensation technique.

Aim/Objective: The aim of this study is to compare the antimicrobial efficacy of QMix ^TM 2 in 1, sodium hypochlorite (NaOCl), and chlorhexidine (CHX) against Enterococcus faecalis and Candida albicans. Materials and Methods: Eighty freshly extracted, single-rooted human mandibular premolar teeth were instrumented and autoclaved. Samples were divided into two groups of 40 teeth each based on the type of microorganism used. Group I was inoculated with E. faecalis and Group II with C. albicans and incubated for 3 days. Each group was subdivided into four subgroups based on the type of irrigant used. Group IA, IIA, 5.25% NaOCl; Group IB, IIB, 2% CHX; Group IC, IIC, QMix ^TM 2 in 1; and Group ID, IID, 0.9% saline (the control group). Ten microliters of the sample from each canal was taken and was placed on Brain Heart Infusion agar and Sabouraud dextrose agar. The plates were incubated at 37°C for 24 h and colony forming units (CFUs) that were grown were counted. Data was analyzed with analysis of variance (ANOVA) followed by post-hoc Games-Howell test. Results: The greatest antimicrobial effects were observed in samples treated with QMix ^TM 2 in 1 (P < 0.001). No statistical significant difference was found between 5.25% NaOCl and 2% CHX (P > 0.001) against E. faecalis and C. albicans. Conclusion: QMix ^TM 2 in 1 demonstrated significant antimicrobial efficacy against E. faecalis and C. albicans.

Introduction: The present study is designed to assess the apical seal obtained after root end cavity irrigation with MTAD and retrograde filling with mineral trioxide aggregate (MTA) and Biodentine. Materials and Methods: Sixty extracted maxillary central incisors were instrumented and obturated. Apical 3 mm of all the roots were resected and retrograde preparations of 3 mm were made in all the teeth using ultrasonic tips. Thirty root end preparations were irrigated with MTAD for 5 min (Group 1), while 30 were irrigated with saline for 5 min (Group 2). Each main group was subdivided into two subgroups containing 15 samples each. Samples under each subgroup were then filled either with MTA (1A and 2A) or Biodentine (1B and 2B). The amount of microleakage was assessed using a UV spectrophotometer. Results: Statistical analysis suggest a significant difference (P < 0.005) between group 1A and 2A and between the groups 1B and 2B (P < 0.1). There was a significant difference (P < 0.005) between group 1A and 1B and also between group 2A and 2B. Conclusion: Irrigation with MTAD significantly improved the apical seal of Biodentine, but it increased the microleakage in MTA-filled root end cavities. Also the apical seal obtained with Biodentine was superior to that obtained with MTA.

Aim: This in vitro study was carried out to compare the effect of LED light curing system on polymerization and hardness of silorane-based and methacrylate-based posterior composite resin. Materials and Methods: A total of 40 samples, 20 of silorane-based composite Filtek P-90 and 20 of methacrylate-based composite Heliomolar HB measuring 2 mm thickness and 8 mm diameter were prepared using Teflon molds and cured using LED curing light. The samples were polished and tested in Knoop hardness tester using a 50-gram load and dwell time of 15 seconds on top and bottom surfaces. The percentage depth of cure was calculated, and statistical analysis was performed using two-way ANOVA test and Student t- test. Results: Higher statistically significant values were seen for both the top and bottom surface hardness in silorane-based resins than methacrylate-based resins on LED light curing. Conclusion: Greater depth of cure was achieved in silorane-based posterior composite than in methacrylate-based posterior composite resins with a statistically significant difference.

Aim: To compare the fracture resistance and modes of failures of three different aesthetic MOD onlays on endodontically treated premolars. Materials and Methods: Forty sound maxillary premolars were selected of which 10 untreated teeth were taken as control (Group I). The other thirty premolars were subjected to standardized MOD onlay preparations and root canal treatments and divided into 3 equal groups. Onlays were prepared in Group II- Indirect composite, Group III- Lithium Disilicate ceramic and Group IV- Full Zirconia. All onlays were cemented using Multilink Automix. All the 40 samples were subjected to fracture resistance testing on Universal testing machine. Also fractured specimens were observed under stereo-microscope for modes of failure. Results: Group IV presented the highest fracture resistance. Groups II and III presented no significant difference in fracture resistance from each other (P > 0.05). Group II and Group III showed significantly lower fracture resistance values than Group I. Coming to modes of failure, only Group IV had showed no cracks in any of the restorations. Conclusion: Full Zirconia MOD onlays increased the fracture resistance of endodontically treated premolars to a significantly higher level than the sound teeth.

Objective: The effect of 10% sodium ascorbate, 10% grape seed extract, and 10% pine bark extract on the shear bond strength of composite resin to bleached enamel was evaluated. Materials and Methods: Ninety recently extracted human premolars were divided into six groups of 15 teeth each. Except Group I (negative control), the labial enamel surface of all specimens in the other groups were bleached with 37.5% hydrogen peroxide. After bleaching, Group II specimens were stored in artificial saliva for 3weeks before composite bonding. Immediately following bleaching; Groups III, IV, and V specimens were treated with antioxidants 10% sodium ascorbate, 10% grape seed extract, and 10% pine bark extract, respectively, for 10 min and bonded with composite resin. In Group VI (positive control), the composite bonding was done immediately after bleaching. All specimens were stored in deionized water for 24 h at 37΀C before shear bond strength testing. The data obtained were tabulated and statistically analyzed using analysis of variance (ANOVA) and Duncan's multiple range test. Results: The unbleached teeth showed the highest shear bond strength followed by the bleached teeth treated with the antioxidant 10% pine bark extract. Conclusion: Within the limitations of this study, it was observed that the use of antioxidants effectively reversed the compromised bond strength of bleached enamel. Among the antioxidants, 10% pine bark extract application after bleaching showed better bond strength.

Introduction: The purpose of this study was to compare solubility of a new calcium silicate-based cement, Biodentine with three commonly used root-end filling materials viz. glass-ionomer cement (GIC), intermediate restorative material (IRM), and mineral trioxide aggregate (MTA). Materials and Methods: Twenty stainless steel ring molds were filled with cements corresponding to four groups (n = 5). The weight of 20 dried glass bottles was recorded. Samples were transferred to bottles containing 5 ml of distilled water and stored for 24 h. The bottles were dried at 105΀C and weighed. This procedure was repeated for 3, 10, 30, and 60 days. Data was analyzed with one-way analysis of variance (ANOVA) test (P < 0.05). Results: Biodentine demonstrated significantly higher solubility than MTA for 30- and 60-day immersion periods. Statistical difference was noted between the solubility values of Biodentine samples amongst each of the five time intervals. Conclusions: Biodentine exhibited higher solubility in comparison with all other cements.

Background: Giving a time gap and distance during curing can decrease the polymerization shrinkage. Aim: To evaluate the effect of time gap and distance between the curing tip and restoration on the polymerization shrinkage, degree of monomer conversion (DOC), and microhardness of a nanohybrid composite. Materials and Methods: A total of 50 standardized cylindrical specimens (Z350, 3M ESPE) were fabricated using a brass mould. The curing was done in contact with the sample surface for 20 seconds in the control group. In the four experimental groups, curing was initiated at 1-cm distance, followed by variation in the time gap and the curing cycle. The polymerization shrinkage, DOC, microhardness was calculated. Statistical Analysis: One-way analysis of variance (ANOVA) and post hoc-Dunnett test were used to analyze the data. Results: Curing at 1-cm distance for 10 seconds with a gap of 10 seconds and finishing the curing cycle with 20 seconds at 0 cm proved to be an appropriate technique to reduce the polymerization shrinkage without significantly affecting the DOC and microhardness. Conclusion: A simple innovative modification of varying the distance of curing and a time gap in the curing cycle can decrease the polymerization shrinkage without affecting the DOC and microhardness.

Aim: The aim of the study is to evaluate and compare the antimicrobial efficacy of two new materials MTA Plus and Biodentine with ProRoot MTA using tube dilution method. Materials and Methods: The materials used were ProRoot MTA (Dentsply), MTA Plus (compounded by Prevest Denpro, Jammu, India for Avalon Biomed Inc, USA) and a calcium silicate based material Biodentine (Septodont, Saint-Maur-des-Fosses, France). Doubling dilutions of the material were prepared in Sabouraud's dextrose broth (SDB) and Brain Heart Infusion (BHI) broth for Candida albicans and Enterococcus faecalis, respectively. The minimal concentration at which inhibition of microorganism occurred was measured and noted as minimal inhibitory concentration (MIC) of the material. Results: There was no statistically significant difference between the materials against C. albicans. Biodentine was statistically significant than MTA Plus against E. faecalis (P-value-0.022). ProRoot MTA was statistically significant at different time intervals against E. faecalis (P-value-0.001). Conclusion: ProRoot MTA and Biodentine proved to have antimicrobial property. MTA Plusproved as a good antifungal agent.

A malformed tooth characterized by one or more developmental disturbances is often difficult to treat. When such teeth are present in anterior region, they pose a technical challenge for the clinician to restore esthetics as well as function. This case describes endodontic, surgical, and restorative management of fused and dilacerated maxillary central incisor. Cone-beam computed tomography (CBCT) was used in the present case to aid in understanding of complicated tooth morphology and managing the case successfully.

The variability of root canal system morphology presents a continuous challenge to endodontic diagnosis and therapeutics. There have been reports of teeth with multiple roots and canals as also those with lesser number of root and root canals. Variations of root canal systems need not always be in the form of extra canals. Clinicians should be aware that there is a possibility of existence of fewer numbers of roots and root canals than normal, which presents varied canal anatomy and poses a challenge to the clinician's expertise. This case report deals with the management of an unusual case of C-shaped canal in mandibular molar with two buccally fused roots. Cone-beam computed tomography (CBCT) was employed to confirm the extension of the unusual anatomy. The Self Adjusting File (SAF) system was used to ensure complete cleaning of the canal system. One-year follow-up of the case showed good healing. The clinician should expect to encounter unusual features when performing endodontic treatment. Use of diagnostic aids like CBCT, improved magnification with dental operating microscope, and the use of novel file systems like SAF ensure success.

Root-canal-treated teeth are structurally compromised as a result of loss of tooth structure due to caries, iatrogenic cavity preparation, and dehydration. Given that a direct relationship exists between the amount of remaining tooth structure and the ability to resist occlusal forces, it is vital to provide a restoration allowing cuspal coverage as soon as possible following completion of the root canal treatment. A decision to provide a full crown or an onlay depends on the remaining tooth structure; if the cuspal width to length ratio is 1:2 or more, an onlay can be placed. When the ratio is less than 1:2, a full crown has to be planned. In single-rooted teeth requiring post-endodontic restoration cast post and core or a prefabricated post can provide resistance to fracture with comparable results. However, in case of premolars contradictory to the practice of providing only cuspal coverage through Onlays, it would in addition require cervical reinforcement also to counter horizontal forces acting in cervical region. A new onlay design SHARONLAY patented design with I.P. no 1956475 dated 27/04/2010 with a post extending into the radicular portion of the premolar providing the required reinforcement in a conservative manner and protecting it against both vertical and horizontal forces is proposed herewith.