Ex vivo study of manual and rotary instrumentation techniques in human primary teeth.

Objective: This study aimed to evaluate, ex vivo, time and dentin removal by manual and rotary instrumentation in human primary teeth.

Study Design: Eighty primary teeth were divided into 2 groups, embedded in resin, and sectioned for evaluation before and after instrumentation. For manual technique, teeth were prepared using K-type files and rotary preparation was performed with Hero 642. All root canals were prepared up to size 40, and the instrumentation time was recorded. Dentin removal was calculated using digital image software. Data was statistically analyzed using chi-squared, Mann-Whitney, and t tests.

Results: Manual instrumentation removed more dentin in all groups compared with rotary instrumentation (P < .05). In some specimens, root perforations were observed in areas coinciding with largest root resorption. Rotary technique showed the shortest instrumentation time (P < .05).

Conclusions: Deciduous teeth, without significant root resorption, have enough root structure for instrumentation up to size 40. Rotary technique required less time and generated less dentin removal.