Efficacy of Three Different Rotary Retreatment Systems to Remove Laterally and Vertically Compacted Guttapercha: A Cone Beam Computed Tomographic Evaluation

BACKGROUND: Root canal treatment success has been considered to rely on the control of pulp space infection. Infliction on pulp and subsequent peri radicular infection results from the presence of microorganisms, microbial toxins and metabolites, and the products of pulp tissue degradation (Whithworth, 2005). Eliminating these etiologic factors and preventing further irritation from persistent contamination of the root canal are the foundation of nonsurgical and surgical root canal therapy success.This is an in vitro was done to evaluate the effectiveness of three different gutta-percha removing techniques in lateral and vertical compacted obturation technique using cone beam computed tomography. MATERIALS AND METHOD: Ninety (90) single rooted freshly extracted mandibular premolars were selected for this study. All samples were analysed with digital radiograph (Satelec, Acteon, France) in buccal and proximal directions for confirming the existence of single straight canal, fully formed apex, no signs of internal resorption, calcification or previous endodontic therapy, caries and restoration or presence of dentin pins. The samples were decoronated by using a diamond disc to attain a 15mm of standard root length and a reference point. After this, a conventional access cavity was prepared using Endo access bur. The working length was confirmed at 0.5 mm short of the estimated measurement. Then the samples were randomly allocated into two main groups of 45 samples in each. The root canals were obturated using lateral compaction method and warm vertical compaction method. After obturation a primary CBCT was taken to assess the total volume of obturation material in both groups. Then root canals were sealed with temporary filling and the teeth stored at 37˚c in 100% humidity for two weeks. The primary CBCT analysis of all the prepared samples were randomly sub divided into six groups with 15 samples in each according to the retreatment technique. After retreatment the prevalence of the residual filling material in each group was evaluated by estimating in the root canal space by obtaining post op CBCT. The volume of residual filling materialinside the canal was calculated with the following equation Area of remaining filling material ÷ Area of canal wall × 100 = Area of remaining filling material(%). STATISTICAL ANALYSIS: Data were analysed statistically using Statistical Package for Social Sciences (SPSS) Software version 21(IBM Statistics). Data were expressed in its mean and standard deviation (SD) for all the samples tested and were analysed using ANOVA and LSD post hoc test. The level of statistical significance was set at P = 0.05. RESULTS: The results showed that statistically significant difference was observed between Protaper, M-Two, D-Race. The highest mean value was with Pro-Taper file retreatment system in removing the obturation material compared to the D-Race and M-Two systems, irrespective of the obturation method adopted CONCLUSION: Within the limitations of the present study, it can be concluded that 1. Protaper was the most effective system in removing obturating material in lateral and warm vertical compaction groups. 2. The residual filling material in root canal space in which lateral compaction groups shows maximum volume of obturating material when compared to warm vertical compaction group