An article comparing the cleaning effectiveness of manual, hybrid, and rotary endodontic instrumentation techniques in primary molar teeth was published recently in the International Endodontic Journal. This study involved 15 primary molars. After endodontic access, the teeth were immersed in a medium containing Enterococcus faecalis and divided into 3 groups according to the root canal instrumentation technique: group 1 was manual, group 2 was hybrid, and group 3 was nickel-titanium (Ni-Ti) rotary files. For microbiological evaluation, comparisons before and after instrumentation were performed using the paired Student’s t-test. One-way analysis of variance complemented with the Student’s t-test was used to compare the percentage of microbial reduction. Instrumentation time was evaluated by Kruskal–Wallis and Student Newman–Keuls tests. Images obtained under scanning electron microscopy were analyzed by 3 blinded examiners, and kappa statistics was used to evaluate calibration among examiners. The most frequent results among examiners were analysed using Kruskal–Wallis and Student Newman–Keuls tests. The study found that the hybrid technique required a significantly longer instrumentation time than the manual and rotary techniques (P < .05). All techniques tested were able to significantly reduce the number of E faecalis (P < .05). The hybrid technique was associated with the highest intracanal bacterial reduction, with a statistically significant difference compared with manual instrumentation (P = .01). Manual instrumentation resulted in the lowest amount of debris and the highest amount of smear layer when compared with the rotary and hybrid techniques (P < .05). There was no difference between rotary and hybrid instrumentation in the removal of debris and smear layer. The authors conclude that the use of Ni-Ti rotary files is an option for root canal instrumentation in primary teeth.
(Source: Pinheiro SL et al. Evaluation of Cleaning Capacity and Instrumentation Time of Manual, Hybrid and Rotary Instrumentation Techniques in Primary Molars. International Endodontic Journal. doi: 10.1111/j.1365-2591.2011.01987.x; first published online December 22, 2011)
