Effect of reciprocating instrumentation on chlorhexidine substantivity on human dentin: chemical analysis followed by confocal laser microscopy

The present research analyzed the reciprocating instrumentation associated to chlorhexidine (CHX) substantivity as its correlation with E. faecalis viability in ex vivo root canals. Eighty extracted single-rooted human teeth were used, being 40 high-performance liquid chromatography (HPLC) and confocal laser scanning microscopy (CLSM). In both, decoronated cervical third was prepared. CLSM analysis, canals inoculated for 14 days. Samples divided into 4 groups (n=10) according technique: no irrigation distilled water (control); manual (K-File); rotary (ProTaper Next); (Reciproc R25). Two percent applied irrigating substance experimental groups. Longitudinal grooves resulted 2 halves 20 proof bodies each group. by chance two outcomes evaluated after days one week. retained live cells techniques evaluation time measured HPLC CLSM, respectively. Specific analysis tests (p≤0.05). Both well significantly reduced amount of on dentin all observation periods (p<0.05). After times, presented lower compared control, but without statistically difference. Intragroup comparisons times showed differences techniques, retention number (p>0.05). Reciprocating does not interfere substantivity.