Conservation of dentin thickness in the root canals orifice following two preparation techniques

Objective: The aim of this study was to evaluate the amount of dentine removed after canal preparation using ProTaper (PT) and Greater Taper (GT) rotary instruments. Materials and Methods: Twenty extracted human teeth with single roots were selected and sectioned at the level of CEJ. The roots were distributed in two groups (n= 20) using stratified randomization, and prepared under simulated clinical conditions with ProTaper (PT) and Greater Taper (GT) rotary NiTi system. The pre- and post-preparation photographs were traced and superimposed, dentin thickness was measured at the levels of canal periphery, canal area, tooth area, mesial dentin thickness, distal dentin thickness, buccal dentin thickness and lingual dentin thickness both before and after preparation. Results: The thickness of removed dentin was significantly different between the two preparation techniques (p<0.01) at the level of both tooth and canal area with more conservation for GT system while ProTaper system more conservative at buccolingual width than mesiodistal width, and GT system was more conservative at mesiodistal dimension than buccolingual dimension. Conclusion: GT rotary instrumentation prepares root canals has greater conservation of dentine structure on the overall dimensions of the root, while the ProTaper system is more conservative at buccolingual dimension.