Sealing Ability Comparison of Three Different Obturating Systems to Intraradicular Dentin-An In Vitro Stereomicroscopic Study.

Background: Different obturation techniques are being used to improve canal sealing, thereby minimizing marginal leakage. Aims and Objectives: To evaluate the marginal leakage of three different obturating materials and techniques using stereomicroscope. Materials and Methods: Thirty freshly extracted maxillary anterior teeth were collected and were divided into three groups of 10 each for which the biomechanical preparation was done. The teeth were divided into three experimental groups according to the obturation material and technique used, Group I: gutta-percha with AH Plus root canal sealer (lateral condensation): Group II: thermoplasticized gutta-percha technique-non-carrier-based (calamus) with AH Plus sealer (backfill): Group III: C point (self-sealing root canal obturating system) with bioceramic sealer (single cone). Each specimen was subjected for testing apical sealing ability. The values of microleakage associated with different root canal sealers were evaluated using a stereomicroscope. Results: There was no statistically significant difference in the mean scores of apical dye penetration/leakage among all the three groups (P = 0.091), whereas Group I showed a higher degree of apical leakage than the other techniques tested. Conclusion: None of the tested filling materials provided a gap-free or void-free root canal filling; however, thermoplasticized gutta-percha is used with AH Plus sealer exhibited less voids and gaps when compared to other tested materials.

Influence of Access Cavity Design on the Fracture Strength of Endodontically Treated Teeth Restored Using Short Fiber-Reinforced Composite and High Strength Posterior Glass Ionomer Cement.

AIM: This in vitro study aimed to determine the influence of access cavity design and residual tooth structure and to compare the fracture resistance of the teeth post endodontically restored with short fiber-reinforced composite (GC everX Posterior; GC, India) and conventional posterior high-strength GIC (Glass Ionomer Cement) (GC Gold Label IX; GC, India). METHODS: Ninety extracted human mandibular molars were classified into five groups, i.e., one control group (n = 10) and four test groups based on the access cavity design (n = 20): Traditional access cavity (TAC), Conservative access cavity (CAC), Ninja access cavity (NAC), and Truss access cavity (TRAC). Then 80 teeth in test groups were endodontically treated and further subdivided (n = 10) based on post-endodontic restorative materials, i.e., short fiber-reinforced composite (SFC) and Type 9 GIC. Samples were then subjected to fracture resistance under a universal testing machine and fracture loads were compared statistically. RESULTS: The fracture resistance of various access cavity designs (TAC, CAC, NAC, and TRAC) varied significantly (P < .05). Regardless of access cavity design, teeth restored with SFC had higher fracture resistance than teeth restored with high strength posterior GIC (P = .001). CONCLUSION: Using newer access cavity designs like (CAC, NAC, and TRAC) and reinforcing the teeth with a post-endodontic restoration such as SFC, fracture resistance of endodontically treated teeth can be improved notably.

Efficacy of Different Methods for Removing Root Canal Filling Material in Retreatment - An In-vitro Study.

INTRODUCTION: Although success of endodontic therapy has significantly improved in the last few decades due to the introduction of novel materials and techniques, failures of endodontic therapy requiring re-treatment still comprise a significant percentage of patients requiring root canal treatment. AIM: To evaluate and compare the effective removal of gutta percha and sealer, amount of apical debris extrusion and time required for gutta percha removal using various endodontic files. MATERIALS AND METHODS: Total 48 extracted mandibular premolars were mounted on acrylic blocks and endodontic procedure was carried out using size 40 K file and obturated using guttapercha and zinc oxide eugenol sealer. After one month storage, samples were decoronated, mounted on screw capped vials and subjected to removal of obturated material by four instruments: H files, safe sided H files, protaper universal retreatment rotary system and ultrasonic retreatment tip, grouped as 1, 2, 3, and 4 respectively. Only 2mm of obturated material from the coronal part was removed using no. 3 Gates Glidden drill, guttapercha was softened with a drop of xylene for 2 mins for each canal and retreatment was performed. The retreatment procedure was said to be complete when no visible debris were observed on the instrument flutes. The samples split into two halves and examined under stereomicroscope, photographed, assessed using AUTOCAD software and percentage of remaining filling material in coronal, middle, apical thirds of the canal was calculated in mm(2). Retreatment time was recorded in seconds and apically extruded debris was assessed by microbalance in grams for each tooth. The data was analyzed by using descriptive statistics, ANOVA and Scheffe's post hoc test through SPSS for windows (v 16.0). RESULTS: The ultrasonic retreatment tip had less percentage of residual guttapercha/sealer, shorter mean operating time and little apical extrusion with a significant difference (p<0.05) between the other groups. CONCLUSION: All techniques retained guttapercha/sealer remnants within the root canal. The ultrasonic retreatment tip proved to be an efficient method of removing obturated material. It was fastest with least apical debris extrusion.