Objective: This work evaluated the variation of temperature, heating rate, and cooling rate of two types of guttapercha cones; conventional cones (CV) and thermoplastic cones (TP). Materials and Methods: The cones were inserted within a bovine bone block containing a vertical artificial canal and an electric heat carrier was introduced until 4.0 mm from the cone end. A K-type thermocouple recorded the temperature variation. Results: CV showed greater variation of temperature; the heating rate was higher in CV (P = 0.01). There was no significant difference in the cooling rate (P = 0.26). The temperature variation and the heating rate were higher for CV. The cooling rate was not different between CV and TP. Conclusion: Under the present study conditions, no advantages were found in using TP compared with CV.

The successful outcome of endodontic treatment depends on the reduction or elimination of bacteria present in an endodontic infection. It has been reported that chemo-mechanical instrumentation alone is not enough for this purpose. Bacteria survive even after most thorough instrumentation. These remaining bacteria grow and multiply inside canal if no antibacterial dressing is used between endodontic appointments. This in vitro study was conducted to evaluate the pH changes after intra canal placement of different calcium hydroxide formulations and to determine their alkalizing potential to be effective as an interim dressing material.

Objective: The aim of the present study is to compare the in vitro changes in the fracture resistance of human root dentin when exposed to intracanal Ca(OH)₂ , MTA and CPC. Methodology: Fifty six freshly extracted single rooted teeth were selected and divided into four following groups of 14 teeth each Group I – saline group (control group), Group II - Ca(OH)₂ group, Group III – MTA group, Group IV – CPC group Coronal access and endodontic instrumentation was done using specified instruments and techniques. The prepared canal was filled with saline solution, Ca(OH)₂ paste, MTA and CPC and sealed with bonded composite resin and teeth were immersed in saline. After 30 days and 180 days the roots of 7 teeth from each group were sectioned horizontally into 1mm thick disks depending upon length of root into 4-5 sections and each disk was placed under a universal testing machine and the peak load at fracture was recorded. The mean peak load at fracture for each group was calculated and the results from all groups were compared by a one-way ANOVA and a post hoc student – Newman – Keuls test. Results: Results showed that the mean peak load at fracture of Group I (saline group) was higher in both 30 days and 180 days specimen. Ca(OH)₂ group showed a decrease in the fracture resistance as compared to all other groups in 30 and 180 days specimen. Conclusion and Interpretation: Based on results, both MTA and CPC can be efficiently used as an alternative to Ca(OH)₂.

Aim: To comparatively evaluate the efficacy of plastic endodontic rotary finishing file (F- file) with rotary ProTaper, Stainless Steel K-file and RaCe, regarding smear layer removal. Materials and Methods: Thirty healthy maxillary premolars with two separate buccal and palatal canals were selected. Both buccal and palatal canals of each group (n=10) were instrumented by rotary ProTaper, Stainless Steel K-file and RaCe respectively and irrigated with 17% EDTA and 5% Sodium Hypochlorite. Then palatal canal of each specimen was finished with F-file for smear layer removal. Then each specimen was visualized using scanning electron microscopy. Buccal and palatal canals of each specimen were compared for smear layer removal. Results: The statistical analysis was done using wilcoxon score and found no significant difference in smear layer score after using plastic file(p>0.005). Conclusions: It appears that finishing with plastic file (F-file) did not help in reducing smear layer and obtaining a better finished root canal.

Objectives - This study compared guttapercha and GuttaFlow in filling lateral grooves and depressions in apical 7 mm of a split tooth model. Study design - A split tooth model with lateral grooves and depressions at 7, 5, 3 and 1 mm from the working length was used. The groups included were (n= 10):Gutta Flow(Group 1); Gutta-percha obturation with system B plugger inserted 5 mm from the working length (Group 2); 4 mm from the working length ( Group 3); and 3 mm from the working length ( Group 4). The model was then viewed under a stereomicroscope at 10 X and scored. Statistical analysis was done using Friedman's test and Wilcoxon signed rank test. Results - GuttaFlow flowed better than gutta-percha into depressions at 1 and 3-mm levels when System B plugger was inserted 5 mm and 4 mm from the working length. Gutta-percha flowed significantly better at 1-mm level defects when the System B plugger was inserted 3 mm from working length compared with 5 mm and 4 mm from working length. Conclusion - GuttaFlow flows significantly better in the apical 3 mm of a split-tooth model than gutta-percha placed using warm vertical technique but also is apically extruded.

The present study was done to evaluate the cytotoxicity of different root canal sealers on target cells, HEK-293 (human embryonic kidney epithelial cells) and Vero (African green monkey kidney epithelial cells). Specimens of Endomethasone N, EndoREZ, Acroseal, RoekoSeal and AH Plus were prepared for direct contact with cultured cells and as extracts in the MTT assay. HEK-293 and Vero cells were used as toxicity targets. Differences in cytotoxicity between fresh and set specimens (0 hours, 24 hours, 48 hours, 72 hours and 1week) and between the extracts of root canal sealers were determined by using SPSS Version 15.0 (SPSS, Inc., Chicago, IL, USA) statistical software package (p < 0.05). The results showed that extracts of Endomethasone N were more toxic, as compared to all other groups (p<0.05) on both cell lines. Extracts of EndoREZ were least toxic and mean value of percentage inhibition was significant as compared to all the other groups except Acroseal (p=0.059) on both cell lines. The mean value of AH Plus was found to be significantly higher as compared to EndoREZ and Acroseal (p<0.001) on both cell lines. The mean value of RoekoSEAL was significantly higher as compared to Acroseal (p=0.036) on Vero cells but not significant on HEK-293 cells. The study concluded that Endomethasone N exhibit highest toxic towards cultured cells. EndoREZ and Acroseal were comparatively less toxic whereas RoekoSEAL and AH-Plus showed intermediate cytotoxicity.

Objectives: The objective of this study was to compare the cytotoxicity among four sealers, Realseal, Apexit Plus, Guttaflow, AH Plus after setting and evaluating them at 24 hours, 7^th day and 14^th day and to also compare the cytotoxicity of these individual sealers at different time intervals i.e. 24 hours, 7^th day and 14^th day. Materials and methods: Human gingival fibroblasts were cultivated in 25 cm³ tissue culture flasks containing Dulbecco's Modified Eagle's Medium (DMEM) and sub confluent monolayers of cells were obtained. Nine discs of each sealer were prepared in sterile Teflon moulds and allowed to set for 24 hours (3discs), 7days (3discs), 14days (3discs) respectively. All discs based on 24 hours, 7^th day and 14^th day setting duration were then placed in cell culture medium (DMEM) for a duration of 24 hours to obtain the elutes.The elutes of all sealers at different time intervals were added to the human gingival fibroblast cultures and their cytotoxicity was assessed by MTT assay and spectophotometric analysis. The results were tabulated and subjected to statistical analysis. Results: Statistical analysis revealed that there was a significant difference in cell viability between Realseal and Guttaflow at the 7^th day time interval. Realseal was the most toxic at all time intervals and Guttaflow was the least toxic at all time intervals compared to the other two sealers tested. Conclusion: All sealers showed a varied amount of cytotoxic response from lowest toxicity to highest toxicity in the increasing order i.e. Guttaflow <AH Plus <Apexit Plus <Realseal. All the sealers were initially toxic at the 24^th hr and the toxicity decreased over time as the sealers set. Apexit Plus showed slight toxicity up to almost the 7^th day after which the toxicity reduced drastically by the 14^th day. AH Plus showed consistent amount of slight toxicity at all time intervals.

Objectives: The objective of the study was to compare the bond strength of Epoxy resin based and UDMA based sealers and to assess the relative bond strengths between Dentin-Sealer and Sealer-main cone, by testing canals filled with and without a main cone. Materials and method: Thirty extracted maxillary premolar teeth with two separate canals were prepared using 0.06 taper K3 instruments to size 35. Teeth were divided into three groups for filling using AH Plus™, EndoREZ^® or Realseal^® sealers. In each tooth, one canal was filled with a matching single-cone technique, and other was filled with sealer alone. A 1 mm slice of mid-root dentine was prepared for the push-out test. Failure modes after push-out were examined under stereomicroscopy and scanning electron microscopy. Results: Overall, the epoxy resin-based sealer provided the highest push-out bond strengths. Push-out bond strengths were significantly higher (p < 0.001)when canals were filled with sealer alone than those filled with main cone and sealer. Sealers failed in cohesive mode within the thin film, leaving a layer of sealer on the canal surface. Bulk sealer showed predominantly adhesive failure at the dentine–sealer interface, with a clean dentine wall and with resin tags either partially pulled out or sheared off at the interface. Interpretation and Conclusion:

1. Epoxy resin based sealer had the highest push-out bond strength compared with UDMA based sealers when used with main cone.
2. The bond strengths after filling with sealer alone were higher than those with main cone and sealer and may reflect different patterns of behavior when the sealer is present in thin layer.

The present study compared the penetration depth into the dentinal tubules of RealSeal with that of Tubliseal by means of Confocal Microscopy. Twenty sound extracted, single-rooted premolars were selected. Following completion of root canal instrumentation, the teeth were divided into two groups and were filled with guttapercha and Tubliseal using cold lateral condensation (group 1) and RealSeal (group 2).The sealers were labelled with Rhodamine B dye and confocal microscope was used to assess the penetration depths.According to the results of the present study, the mean penetration depth of RealSeal sealer into the dentinal tubules was higher than the penetration depth of Tubliseal.

Aim: To evaluate the effects of polyethylene fiber insertion on fracture resistance of root-filled teeth with MOD preparations restored with composite resin. Methodology: Eighty extracted maxillary premolars were assigned to 4 groups. Group1: No treatment. Group 2,3,4: Teeth received root canal treatment and MOD preparations. Group2: Left unrestored. Group3: Restored with composite. Group4: polyethylene fiber inserted in bucco-lingual direction+composite restoration. Compressive forces were applied on tooth. The force necessary to fracture were recorded in Newton and submitted to Kruskal- Wallis ANOVA and Mann-Whitney U- tests. The fractured specimens were examined to determine the fracture levels. Results: Fiber reinforced teeth showed significantly improved fracture resistance than Group2 and 3. Failure modes of reinforced teeth were limited to enamel, while others were more extensive. Conclusion: Composite restorations reinforced with polyethylene fibers showed increased fracture resistance of root filled teeth and had favorable fracture lines.

Objectives - This study was undertaken to evaluate the efficiency of three rotary nickel titanium instruments and hand instrumentation in removing gutta-percha and sealer from root canals. Study design - 60 extracted human maxillary central and lateral incisors were instrumented with K-files and filled using lateral compaction of gutta-percha (GP) and AH Plus sealer. The teeth were randomly divided into four experimental groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: ProTaper Universal rotary retreatment system, R-Endo retreatment files, Mtwo retreatment files and Hedstrom files. Time to reach working length and to eliminate filling material was also recorded. The specimens were rendered transparent for evaluation of the area of the remaining gutta-percha/sealer under stereomicroscope at 6X magnification. Photographs were taken for further analysis using computer image analysis program. The results were statistically analyzed using ANOVA and Bonferroni test. Results - The ProTaper Universal retreatment system resulted in a smaller percentage of canal area covered by residual GP/sealer than in other groups, but a significant difference was found between ProTaper and Mtwo group and between ProTaper and Hedstrom group (P < 0.001). The Mean operating time was minimum with Mtwo group (5.08±0.64 min) while it was found to be maximum with hand files (7.93±1.03 min). Conclusion - It was concluded that all test techniques left gutta-percha/sealer remnants within the root canal. The ProTaper Universal rotary retreatment system proved to be an efficient method of removing gutta-percha and sealer from maxillary central and lateral incisors.

Objectives: To evaluate the four electronic apex locators namely (Propex II, Root ZX, Ipex, Neosono Co-pilot) to determine the working length in teeth with simulated oblique root fracture. Study design: Thirty permanent maxillary incisors were used. Standard access cavities were prepared. An incomplete notch was made simulating an oblique root fracture. True working length with respect to the fracture plane was determined. A model was prepared for measuring the working length using apex locator. Data was compared with the true working length, allowing a tolerance of 0.5mm and 1mm. Analysis of variance and chi-square test were performed to analyze the results. Results: All the apex locators were more accurate and statistically similar at 1mm tolerance. At 0.5mm tolerance, statistically significant differences were found. Conclusion: A tolerance limit of 1mm can be considered acceptable, especially in cases of oblique root fracture

The aim of this in vivo investigation was to determine the accuracy of 3 different Electronic Apex Locators with 3 different instrument sizes. 30 patients who were scheduled for root canal therapy with single canals were included in this study after appraisal of the procedure and informed consent was obtained. Electronic measurements were made to the physiologic foramen with Neo Sono Copilot, Tri Auto ZX and Propex. Statistical significance was calculated with one way ANOVA and Sign test. All three electronic apex locators could accurately determine canal length to within +/- 0.5mm from the apical constriction in 75% to 88% cases. The instrument sizes 08, 10 have significant influence and file size 15 does not have significant influence on the accuracy during working length determination with investigated Electronic Apex Locators. A tendency of all investigated devices and instruments to make shorter rather than longer measurements was recorded.

Background and Objectives - To evaluate and compare the radicular peroxide penetration from different concentrations of carbamide peroxide bleaching gels (10%, 16%, 35%) and a mixture of 30% hydrogen peroxide and sodium perborate. Methodology - Root canal treatment was performed on 50 extracted human maxillary premolars. Teeth were randomly divided into 5 groups and pulp chamber was filled with distilled water (group I), with 10%, 16%, 35% carbamide peroxide gels (group II, III, IV) and mixture of 30% hydrogen peroxide and sodium perborate (group V) respectively. The amount of hydrogen peroxide penetration in each sample was measured after 24 hours using ferro-thiocynate method. Data was analyzed using Kruskal-Wallis analysis of variance and Mann-Whitney U test. Results - Group V had statistically significant higher peroxide penetration when compared with other groups. Conclusion - Peroxide penetration from carbamide peroxide gels is less than sodium perborate-hydrogen peroxide mixture, therefore carry less risk of post bleaching external root resorption.

This study reports the results of a comparative study carried out to assess the strain generated during lateral condensation of curved root canals using Stainless steel and Nickel titanium spreaders. The measurements were carried out using strain gauges and the results indicate that NiTi spreaders cause less strain than the stainless steel spreaders. This could be attributed to the lesser rigidity observed for NiTi spreaders.

Management of crown-root fractures presents a formidable challenge for clinicians because of the difficulty in achieving a stable union of the fractured fragments. Root fractures in permanent teeth are uncommon injuries among dental traumas accounting for 0.5-0.7% of the cases. These case reports describe the various clinical presentations of horizontal crown-root fractures and the different treatment modalities that we as clinicians can offer to these patients. An attempt to treat these horizontal oblique fractures at various levels with these different diagnostic and treatment approaches has been solicited. Stabilization of these fractures was achieved by intra-radicular splinting and MTA as well as re-attachment of the fractured fragments. Short term follow up results showed successful management of these cases using the treatment modalities mentioned above.

Aim: To determine the bacterial count in different sources of water in the dental unit and the role of flushing dental water lines for the removal of the bacteria. Materials and Methods: Five private dental clinics were surveyed in this study. Initial water samples were collected in a sterile leak proof container from air-water syringe, high speed air turbine hand-piece and from oral rinse source following infection control protocol. They were then subjected to microbiological analysis for the bacterial count. A second sample was taken after three minutes of flushing from the same sources and quantitatively analyzed for bacterial count. The results were analyzed statistically. Results: The flushing process reduced the bacteria by 0.245 log₁₀ CFU/ml in case of air water syringe, 6.181 log₁₀ CFU/ml in case of high speed air turbine hand-piece and 2.828 log₁₀ CFU/ml in case of oral rinse. The highest amount of bacterial contamination was seen in high speed air turbine hand-piece followed by oral rinse source and finally air water syringe. Conclusion: The results support U.S. Centers for Disease Control and Preventive recommendations that the process of flushing dental water lines cannot be relied upon as a sole means of reliably improving the quality of water used in dental treatment.

Calcium hydroxide as a root canal medicament has been used in endodontics for many years. The use of calcium hydroxide in clinical situations involving necrotic pulp is advantageous as a result of its antiseptic action on the microorganisms present in the main root canal, its ramifications in the dentinal tubules, as well as in the apical cementum. It's biologic and antiseptic effects rely on alkalinity and calcium ion release. Release of calcium and hydroxyl ions into periapical area is dependent upon time and the type of vehicle used. The present in-vitro study was aimed to evaluate and compare calcium concentration and pH of the periapical environment after applying calcium hydroxide into root canals. Fifty single rooted single canal extracted teeth were divided into five groups. After access opening, cleaning and shaping calcium hydroxide was placed inside the canals in following order. Group 1-calcium hydroxide was mixed with distilled water at a powder/water weight ratio of 38%; group 2-calcium hydroxide was mixed with distilled water at 44%; group 3-calcium hydroxide was mixed with distilled water at 50%; group 4-calcium hydroxide powder only was used; and group 5-the control group, in which nothing was applied to the canals. All samples were immersed in distilled water maintained at 37°C. Calcium concentration and pH of the distilled water were measured after 3 days, 7 days, and then at weekly intervals up to 5 weeks, during which time the storage medium was renewed after each measurement. Calcium concentration and the change in pH of the distilled water were statistically quicker and greater in groups 1 to 3 (mixture groups) than group 4 (powder only). The highest calcium concentration (peak Ca²⁺ release) was observed after 3 days for the mixture groups, whereas that for the powder only group was found at 7 days. Peak pH change was found after 3 days for the all groups. After peaking, all groups showed a decline of the pH over time. These results suggest that the time required for optimum intracanal activity when using calcium hydroxide mixtures is at least1 week.

Full mouth rehabilitation always claims careful attention and meticulous treatment planning. It continues to be the biggest challenge to any clinician in Restorative Dentistry. It requires efficient diagnosis and elaborate treatment planning to develop ordered occlusal contacts and harmonious articulation in order to optimize stomathognathic function, health and esthetics which then translates to patient's comfort and satisfaction. The severe wear of anterior teeth and the collapse of posterior teeth results in the loss of normal occlusal plane and the reduction of the vertical dimension of occlusion. This case report is of full mouth rehabilitation of a 55 years old patient with multiple decayed and attrited teeth with loss of vertical dimension.

Taurodontism can be defined as a change in tooth shape caused by the failure of Hertwig's epithelial sheath diaphragm to invaginate at the proper horizontal level. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cemento-enamel junction are the characteristic features. Endodontic treatment of a taurodont tooth is challenging and requires special handling because of the proximity and apical displacement of the roots. Here, we report three cases of taurodontism, all of them were treated endodontically.

The aim of this case report is to describe the management of radix entomolaris with external root resorption and grade III furcation involvement using mineral trioxide aggregate and root resection. A 27 year old male patient with noncontributory medical history reported with tooth 46 showing sign and symptoms of pulpal necrosis, apical periodontitis, external root resorption and grade III furcation involvement. Root canal treatment was completed in the mesial root only. As the caries extension was too subgingival on the distal side, resection of the distal root and the radix was performed, to ensure adequate coronal seal. The external resorptive defect was then curetted and repaired with MTA. After 3 months of follow-up, the clinical and radiographic examination showed a significant healing and loss of pocket depth around the mesial root.

This case report deals with the multidisciplinary approach of an 18 year old with Amelogenesis Imperfecta of the Hypoplastic type. The patient came with a chief complaint of small sized teeth and unsatisfactory aesthetics. No abnormalities were detected in her past medical history. Her family history revealed similar condition in her father and her sibling (sister).On clinical examination, the crowns of all teeth were small, discoloured, worn out and hypoplastic. The roots appeared normal on radiographic examination. The aim of the treatment was to preserve the tooth structure, restore the vertical dimension, improve esthetics and masticatory function. The treatment procedures involved endodontic, restorative and periodontic interventions. After recording the vertical height by a facebow transfer, endodontic treatment and crown lengthening were performed w.r.t the upper anteriors. As the patient showed a high smile line, periodontal surgery was carried out for the upper anterior teeth to obtain an average smile line. The lost vertical dimension was regained in a phased manner by placing full coverage crowns for all the teeth. Thus by systematic and sequential interdisciplinary treatment approach the patient's esthetic and functional requirement was fulfilled.

Fracture of maxillary central incisors is the most common dental injury seen in today's hectic life due to increased road accident, contact sports or other accidents. It not only causes pain but affects the patient's esthetics to a large extent. This always is the first concern of the reporting patient. Reattachment of the fractured fragment is possible when patient seeks immediate dental treatment along with the fractured fragment. This clinical case report describes the treatment of a complex crown fracture of right maxillary central incisor using fractured fragment along with prefabricated post. The fragment was attached using composite. This re-establishes the functions and esthetics of the patient in single visit. During follow up appointment, clinical and radiographic examination revealed no complications. This suggests the efficacy of the treatment in retaining the fractured tooth.

Root anatomy is highly complex and unpredictable. The knowledge of normal anatomy and its frequent variations can greatly enhance the success rate of endodontic practice. Mandibular molars can have an additional root located lingually (the radix entomolaris) or buccally ( the radix paramolaris ).The prevalence of these three-rooted mandibular molars appears to be as low as 0.2 % in Indian population whereas it is higher than 5% ( even upto 40% ) in populations with Mongolian traits. If present, an awareness and understanding of this unusual root and its root canal morphology can contribute to the successful outcome of root canal treatment. This case series aims to describe this unusual root morphology and their successful endodontic management drawing particular attention to radiographic interpretation, access refinements for diagnosis and challenges in cleaning and shaping to increase the ability of clinicians to treat such cases successfully.

The introduction of Cone Beam Computed Tomography (CBCT) specifically designed to imaging the maxillofacial region is a true shift from a 2D to 3D imaging. As the CBCT requires only a single scan to capture the entire object with a cone of X-rays, effective radiation dose is significantly reduced when compared with conventional computed Tomography (CT). Periapical disease can be detected earlier with CBCT as compared with conventional radiography. Besides this, CBCT can eliminate anatomical noise, detect the true nature of resorptive lesions, assess root canal anatomy and root fractures. This new technology certainly represents a new technology in contemporary dentistry. The aim of this article is to provide information on CBCT and its potential applications in endodontic practice.