الفهرس | Only 14 pages are availabe for public view |
Abstract Aim: The aim of this study was to evaluate the shaping ability of S5 rotary system in relation to ProTaper Universal system in preparation moderately curved mesiobuccal root canals of extracted human mandibular molars regarding their effect on the canal transportation, centering ability and canal curvature change. Materials and methods: A total of thirty mesiobuccal root canals of extracted human mandibular first molar with the angle of curvature ranging 20-40 {u0366} (according to Schneider) were collected and divided into two equal groups; ProTaper and S5. After access cavities preparation and working lengths determination, the distal roots with the respective part of the crowns of all samples were sectioned at the furcation level and discarded.Samples were mounted in two moulds of acrylic resin for pre-instrumentation imaging using CBCT. Root canals preparations were done according to the manufacturers’ instructions of each NiTi system. The post-instrumentation imaging using CBCT was done with the exacte parameters of pre-instrumentation imaging. The pre and post-instrumentation CBCT images were superimposed using a fusion module of OnDemand 3D App software to measure the dentin thickness at the same root canal levels(3, 5 and 12 mm from the tooth apex). Canal transportation and centering ability were recorded according to formula introduced by Gambill et al (1996), while the change in the angle of canal curvature was recorded following Estrela et al (2008). Data was tabulated and statistically analyzed.Independent samples t-test was used for comparing the variables between the two groups at each root canal level and also was used for comparing the percentage of change in the canal curvature angle between the two groups.Within each group, the canal transportation and centering ratio were compared at the three root canal levels using GLM repeated measure ANOVA procedure. Fisher exact tests are applied to compare the direction of transportation between the two groups.The significance level is considered at P {u2264} 0.05 |