Comparative assessment of dentinal microcrack formation in endodontically retreated teeth using continuous and reciprocating motion – an in vitrostudy

Aim; To Evaluate And Compare Dentinal Micro Crack Formation In Endodontically Retreated Tooth Using Protaper Universal Retreatment System (Dentsply Maillefer, Ballaigues, Switzerland)&Reciproc File System (VDW, Munich, Germany).
Materials and Methods: Freshly extracted 40 mandibular premolars with single straight canal were selected. Decoronation was done using diamond coated disc, leaving the tooth approximately 16mm length. A silicon impression material (Aquasil LV Dentsply caulk, U.S.A) was used for coating the cemental surface of roots to simulate periodontal ligament space. Then all roots were embedded in acrylic blocks made of self-cure acrylic resin.Working length determined and biomechanical preparation followed by obturation done using F3 GP cones.Teeth were randomly divided in to 2 experimental groups (n=20)Group A and Group B. All roots were sectioned perpendicular to the long axis at 3, 6, and 9mm from the apex using a diamond coated disc under water cooling and stereomicroscopic microscopic examination is doneand statistical analysis is done.
Results: The incidence of dentinal defects (microcracks) did not differ significantly between the ProTaper&Reciproc group. (P > .05).
Conclusion: They evaluated the incidence of dentinal defects after root canal preparation with reciprocating instruments (Reciproc and Wave-One) and rotary instruments (ProTaper and Mtwo) and determined that instrumentation with Reciproc files was associated with significantly more complete cracks compared to Mtwo and ProTaper.