Aim: To compare and analyze the incidence of root dentinal defects when root canals were prepared with instrumentation in rotary, reciprocation and hand motions.
Materials and methods: 60 freshly extracted mandibular first molars for periodontal reason with fully formed apices were collected. Mesial roots with the standardized root length of 13mm was obtained. Custom made acrylic blocks were made. All the root samples were randomly divided into four following groups (n=15) based upon the file system used to prepare the root canal. Group I: No preparation (control), Group II: Wave one Gold, Group III: MTwo, Group IV: Protaper Universal – Manual.
Working length was standardized as 12.5mm. Final apical diameter was standardized as size 25. All roots were sectioned horizontally at 9mm, 6mm and 3mm from apex. All 45 root sections in each group were examined under stereo-microscope to examine dentinal cracks or craze lines. Results were statistically analyzed.
Results: All three motions of instruments produced dentinal defects at all levels. All three experimental groups produced lesser dentinal defects in apical 1/3 level and more dentinal defects on coronal 1/3 level. MTwo file system produced more number of dentinal defects compared to Wave One Gold and Protaper universal manual files.
Conclusion: Protaper manual files produced lesser dentinal defects compared to Wave one Gold reciprocating and M Two rotary files. M two rotary instruments produced the most complete fractures compared to WaveOne Gold and Protaper universal manual files.
