LIMA, G. A.; http://lattes.cnpq.br/5713548513100883; LIMA, Gabriela de Andrade.
Resumo:
The purpose of this study was to compare the antibacterial efficacy of 0,2%
polyhexamethylene biguanide solution (PHMB) and 2% chlorhexidine (CHX) as
irrigants against Enterococcus faecalis (E.F) infecting root canals. Fifty distal roots of
mandibular human molars were selected and randomly placed in the following
groups: PHMB (N=20), CHX (N=20), positive control (N=5) and negative control
(N=5). With the exception of negative control, the roots were inoculated with E.
faecalis (ATCC 29212) in BHI broth. The teeth were incubated under 370C for 4
weeks and fresh BHI broth was replaced every week to ensure bacterial viability.
Canals were rinsed with 1mL sterile 0.9% saline solution to remove unattached cells,
and samples were collected by using paper points sequentially at the working length,
before (S1) and after (S2) chemomechanical preparation. All bacteriological sample
collection were submitted to quantification by culture. The instrument WaveOne Gold
Large (45/.05) (Dentsply Maillefer, Ballaigues, Switzerland) was used to
instrumentation. The irrigants solutions were delivered by using a 30-gauge needle
between each instrument change, with a total of 3mL used per canal. After
preparation, S2 followed the same pattern as in S1. Qualitatively, PHMB resulted in
all cases with negative culture in S2 (100%). The CHlx group also succeded in
significantly reducing E. faecalis levels, however only one tooth still had detectable
bacteria in S2. It could be observed that 0.2% PHMB solution was highly effective in
reducing E. faecalis. PHMB was able to reduce to zero the bacterial counts, even
having a 0.2% concentration, with results as 2% chlorhexidine.