الفهرس | Only 14 pages are availabe for public view |
Abstract Aim: The aim of this study was to evaluate and compare the 3 file systems; Trunatomy, Protaper next and 2Shape in preparing severely curved mesiobuccal canals (40⁰-60⁰) of mandibularmolars regarding: transportation, centering ability, percent change in canal curvature radius and cutting efficiency, using cone beam computed tomography (CBCT) and a five-digit gram analytical scale. Method: A total of forty-five mesiobuccal root canals of extracted human mandibular molars with the angle of curvature ranging 40-60 ͦ(according to Schneider) were collected and divided into three equal groups; Trunatomy, Protaper Next and 2Shape. Root canal instrumentation was done according to the manufacturers’ instructions of each NiTi system. Pre- and post- instrumentation images were taken using cone beam computed tomography (CBCT) to measure canal transportation, centering ability, percent change in canal curvature radius, differences in dentin thickness and percent change in root canal volume. Pre- and post- instrumentation weights were measured using a five-digit gram analytical scale to calculate the percent change in root canal weight. Result: Trunatomy group had significantly the lowest mesiodistal and buccolingual canaltransportation when compared to 2Shape and Protaper Next groups, especially at the apical level. Protaper Next group had significantly the highest buccolingual canal transportation when compared to Trunatomy and 2Shape groups, especially at the middle level. Concerning the centering ability; there was no statistically significant difference among the three studied groups. Regarding percent change in canal curvature radius, Trunatomy group statistically showed the lowest values in comparison with2Shape and Protaper Next groups. Regarding difference in dentin thickness, Trunatomy group significantly exhibited the lowest amount of removed dentin when compared to 2Shape and ProtaperNext groups in both mesiodistal and buccolingual directions. Regarding percent change in root canal volume, Trunatomy group significantly exhibited the lowest percentage in comparison with 2Shape and Protaper Next groups, as well as 2Shape group had significantly higher percentage than Protaper Next group. Regarding percent change in root canal weight, Trunatomy group significantly recorded lesser percentage than 2Shape group. Conclusion: Under the limitations of the in vitro study, it can be concluded that; the three studied file systems were able to achieve efficient and safe preparation of severely curved MB root canals. Trunatomy files were significantly able to produce less apical canal transportation, less change in canal curvature radius and less amount of removed dentin than the other two file systems. |