Effectiveness of rotary and reciprocating systems on microbial reduction: A systematic review

INTRODUCTION: The role of microorganism and their products in the initiation, propagation, and persistence of periradicular periodontitis has been established. One of the major goals of the treatment of infected root canals of teeth with apical periodontitis is to promote maximal reduction in the intracanal bacterial populations. Engine-driven nickel-titanium instruments possess the latest generation of root canal instruments. The possible benefit of rotary instrumentation over other instrumentation techniques regarding cleaning and disinfecting effects would be irrigant warming and/or turbulence caused by the mechanical rotation of instruments. Furthermore, reciprocating instrument has been introduced for root canal preparation. It has been shown that instruments subjected to reciprocation have increased resistance to fatigue and longer usual life when combined with instruments used in continuous rotation motion. The reciprocating system uses single-file instrumentation technique which can shape and clean the canal in a shorter period and together with the lesser amount of antimicrobial agent. OBJECTIVE: The objective of this study is to compare and evaluate the microbial reduction of rotary and reciprocating systems on microbial reduction. SEARCH STRATEGY: A search was performed in Electronic databases (i.e., PubMed, Cochrane library, Science direct, Lilac, Sigle) using following search terms alone and in combination by means of PubMed search builder from January 1985 to December 2017. SELECTION CRITERIA: Studies were selected if they met the following criteria: In vivo studies comparing rotary and reciprocating system in asymptomatic apical periodontitis patients. MAIN RESULTS: The results showed that the reciprocating system exerted an almost similar antibacterial effect when compared with the rotary system. CONCLUSION: The present systematic review does not provide concrete evidence to show increased antibacterial efficacy of reciprocating system as compared to the rotary system. Furthermore, clinical trials are required to evaluate the efficacy of various instrumentation systems in reducing bacteria from the root canal system.