Resumo

SCHMIDT, Maico Henrique Manica et al. Effectiveness of different auxiliary chemical substances in the rapid disinfection of gutta-percha points - an in vitro study. RFO UPF [online]. 2015, vol.20, n.1, pp. 64-68. ISSN 1413-4012.

Objective: to perform an in vitro assessment of the effectiveness of different auxiliary chemical substances used to promote decontamination of gutta-percha points contaminated with different microorganisms. Materials and method: the microorganisms tested were strains of Enterococcus faecalis, Candida albicans, and Staphylococcus aureus. The 72 gutta-percha points were divided into three groups of 24 points and individually transferred into three tubes containing 5 ml of each bacterial suspension for 1 hour. The 24 gutta-percha points of each bacterial strain were randomly distributed into six groups (n=4) based on auxiliary chemical substance and period of decontamination, as follow: G1 (distilled water; DW); G2 (2.5% sodium hypochlorite; NaOCl); G3 (2.5% calcium hypochlorite; Ca(OCl)2); G4 (2% chlorhexidine gel; CHX); G5 (QMix); and G6 (6.5% grape seed extract; GSE). There were four evaluation periods (30, 60, 90, and 120 seconds). After disinfecting, the gutta-percha points were transferred to tubes containing 450 μL of sterile saline solution, homogenized, and diluted. Aliquots of 100 μL of the solution and the dilutions were cultivated in duplicate on plates containing blood agar. This material was incubated for 48 hours at 37 °C. Next, the number of colony-forming units (CFU/mL) was counted. Results: groups G2 (Na- OCl), G3 (Ca(OCl)2), G4 (CHX), and G5 (QMix) showed no bacterial growth of tested microorganisms at all periods of observation, and were statistically different from all other groups (p<0.05). Group G6 (GSE) showed better antimicrobial activity (p<0.05) against Enterococcus faecalis, Candida albicansi, and Staphylococcus aureus when compared to G1 (DW). Conclusion: we determined that 2.5% sodium hypochlorite, 2.5% calcium hypochlorite, 2% chlorhexidine gel, and QMix might be used as effective agents for rapidly disinfecting contaminated gutta-percha points after 30 seconds of use.

Palavras-chave : Calcium hypochlorite.; QMix.; Grape seed extract.; Enterococcus faecalis.; Candida albicans.; Staphylococcus aureus..