Antimicrobial activity of hypochlorite solutions and reciprocating instrumentation associated with photodynamic...

The aim of this study is to evaluate the antimicrobial activity of hypochlorite solutions and reciprocating instrumentation associated with photodynamic therapy (PDT).

One hundred and thirty two root canals were enlarged up to #35 K-file and inoculated with E.faecalis for 14 days. The 132 samples were randomly divided into eleven groups (n = 12) and subjected to the following protocols: G1-distilled water + Reciproc R40 (control), G2-1% sodium hypochlorite (NaOCl) + Reciproc R40, G3-2.5% NaOCl + Reciproc R40; G4-1% calcium hypochlorite (Ca[OCl]₂) + Reciproc R40, G5-2.5% Ca(OCl)₂ + Reciproc R40; G6-PDT; G7-distilled water + Reciproc R40 + PDT, G8-1% NaOCl + Reciproc R40 + PDT, G9-2.5% NaOCl + Reciproc R40 + PDT; G10-1% Ca(OCl)₂ + Reciproc R40 + PDT, G11-2.5% Ca(OCl)₂ + Reciproc R40 + PDT. The percentage bacterial reduction was checked by counting the colony-forming units (CFUs) in 10 samples of each group. The remaining 2 samples of each group were submitted to scanning electronic microscopy (SEM) to illustrate the effectiveness of the proposed treatments. Data were subjected to one-way ANOVA followed by Tukey's post hoc test (α = 0.05).

The greatest ability to promote bacterial reduction was observed in groups 8 (1% NaOCl + R40 + PDT), 9 (2.5% NaOCl + R40 + PDT), 10 (1% Ca[OCl]₂ + R40 + PDT), and 11 (2.5% Ca[OCl]₂ + R40 + PDT), with no significant difference between them (p < 0.05).

The association of PDT with hypochlorite solutions and reciprocating instrumentation provides effective elimination of E.faecalis.