Atividade antimicrobiana de diferentes medicações usadas em técnicas regenerativas endodônticas sobre o biofilme de Enterococcus faecalis: análise por Microscopia Confocal de Varredura a Laser

Abstract

The aim of the present study was to evaluate and quantify by Confocal Scanning Laser Microscopy (CSLM) analysis, the degree of disinfection provided by different antibiotic medications used in endodontic regenerative techniques, in different formulations and consistencies against strains of Enterococcus faecalis formed in human dentin and comparing to calcium hydroxide. Seventy seven samples of dentin cylindres were contaminated with a culture of E. faecalis for 5 days to form an intratubular biofilm. Samples were divided in six antibiotic groups (n=10, each) according to the formulation of the antibiotic medication tested and their consistency, one group with calcium hydroxide paste (n=10) and one control groups (n=7). TAP/MP group: triple antibiotic medication (ciprofloxacin, metronidazole and minocycline) in solid consistency (vehicles: propylene glycol and macrogol); TAP/MPmod group: triple antibiotic medication (ciprofloxacin, metronidazole and clindamycin) in solid consistency (vehicles: propylene glycol and macrogol); Group BAP/MP: double antibiotic medication (ciprofloxacin and metronidazole) in solid consistency (vehicles: propylene glycol and macrogol); TAP group: triple antibiotic medication (ciprofloxacin, metronidazole and minocycline) in fluid consistency (vehicle: propylene glycol); TAPmod group: triple antibiotic medication (ciprofloxacin, metronidazole and clindamycin) in fluid consistency (vehicle: propylene glycol); BAP group: double antibiotic medication (ciprofloxacin and metronidazole) in fluid consistency (vehicle: propylene glycol); CH group (calcium hydroxide paste, propylene glycol as a vehicle); Group CP: positive control, contaminated, but without antibiotic application. After application of antibiotic medications for 14 days, dentin cylindres were cut lengthwise and the surfaces stained with the fluorescence dye LIVE/DEAD BacLight Bacterial Viability solution and analyzed through CSLM. The images obtained in the CLSM were converted by Leica Software Application Suite-Advanced Fluorescence (Mannheim, Baden-Württemberg, Germany) and after processing in the BioImageLTM v21 software for quantification of the percentage of viable (green) and non-viable (red) bacteria. The non-normal distribution of data was confirmed by the Shapiro-Wilk test, then the Kruskal-Wallis statistical test was performed followed by the Dunn test for multiple comparison between the groups. The level of significance was set at 5% (P < 0,05). The groups that obtained the best results in relation to antimicrobial action were: TAP/MP, TAP/MPmod, TAPmod and BAP. None of the medications eliminated 100% of the bacteria from the intratubular biofilm. It can be concluded that TAPmod, BAP and CH pastes are effective in the intratubular disinfection of the E. faecalis