1.Introduction. The high complexity of the transversal anatomy of the root canal system protects bacteria from chemo-mechanical disinfection frequently resulting in root canal treatment failures. Because of its ability to form biofilms and survive for long time in filled root canals, Enterococcus faecalis is usually isolated from failed root canals that undergo retreatment. The aim of this study was to assess and compare the efficacy, even in depth, of endodontic antimicrobial mixtures in an ex vivo tubule infection model treated with a nucleic acid-binding fluorescent stain and examined by confocal laser scanning microscopy (CLSM). 2.Material and methods. 72 human single-root teeth with fully formed apex were used. Cylindrical root dentine blocks were longitudinally sectioned. Root canals were infected with E.faecalis for 3 weeks to allow penetration into dentinal tubules. Samples were divided into 3 groups: group A was exposed to TRIMIX-M (ciprofloxacin, metronidazole, minocycline), group B to BIMIX (ciprofloxacin, metronidazole) and group C to TRIMIX-C (ciprofloxacin, metronidazole, clarithromycin) for 3 weeks; after that, all specimens were treated with Live/Dead BacLight Viability Stain and examined by CLSM, and the ratio of dead/live bacteria into dentinal tubules was quantitatively analyzed. Differences among groups were analyzed with Kruskall-Wallis and post-hoc Dunn's test (p<0.05). Mean penetration depth of action was recorded and differences were analyzed with one-way ANOVA and post-hoc Bonferroni’s test (p<0.05). 3.Results. Ratio of red fluorescence over total green/red signal in TRIMIX-C, TRIMIX-M and BIMIX groups was 87.1, 84.2 and 76.4%, respectively. The mean depth of action was: TRIMIX-C 520±30 μm, TRIMIX-M 500±60 μm and BIMIX 320±60 μm. 4.Discussion and conclusions. Our previous studies demonstrated the higher TRIMIX-C capacity to kill endodontic pathogens in vitro compared with TRIMIX-M and its ability to avoid tooth discolouration after 3 weeks of incubation. The results of this study confirm that TRIMIX-C even in an ex vivo model shows a higher bactericidal activity, accompanied by excellent penetration in dentinal tubules.
ANTIBACTERIAL EFFICACY OF ANTIBIOTIC COMBINATIONS FOR ENDODONTIC REGENERATIVE PROCEDURES EVALUATED BY CONFOCAL LASER SCANNING MICROSCOPY
ROANA, Janira;MANDRAS, Narcisa;ALOVISI, MARIO;PASQUALINI, Damiano;BERUTTI, Elio;LUGANINI, ANNA;SCALAS, Daniela;TULLIO, Viviana Cristina;CUFFINI, Annamaria
2015-01-01
Abstract
1.Introduction. The high complexity of the transversal anatomy of the root canal system protects bacteria from chemo-mechanical disinfection frequently resulting in root canal treatment failures. Because of its ability to form biofilms and survive for long time in filled root canals, Enterococcus faecalis is usually isolated from failed root canals that undergo retreatment. The aim of this study was to assess and compare the efficacy, even in depth, of endodontic antimicrobial mixtures in an ex vivo tubule infection model treated with a nucleic acid-binding fluorescent stain and examined by confocal laser scanning microscopy (CLSM). 2.Material and methods. 72 human single-root teeth with fully formed apex were used. Cylindrical root dentine blocks were longitudinally sectioned. Root canals were infected with E.faecalis for 3 weeks to allow penetration into dentinal tubules. Samples were divided into 3 groups: group A was exposed to TRIMIX-M (ciprofloxacin, metronidazole, minocycline), group B to BIMIX (ciprofloxacin, metronidazole) and group C to TRIMIX-C (ciprofloxacin, metronidazole, clarithromycin) for 3 weeks; after that, all specimens were treated with Live/Dead BacLight Viability Stain and examined by CLSM, and the ratio of dead/live bacteria into dentinal tubules was quantitatively analyzed. Differences among groups were analyzed with Kruskall-Wallis and post-hoc Dunn's test (p<0.05). Mean penetration depth of action was recorded and differences were analyzed with one-way ANOVA and post-hoc Bonferroni’s test (p<0.05). 3.Results. Ratio of red fluorescence over total green/red signal in TRIMIX-C, TRIMIX-M and BIMIX groups was 87.1, 84.2 and 76.4%, respectively. The mean depth of action was: TRIMIX-C 520±30 μm, TRIMIX-M 500±60 μm and BIMIX 320±60 μm. 4.Discussion and conclusions. Our previous studies demonstrated the higher TRIMIX-C capacity to kill endodontic pathogens in vitro compared with TRIMIX-M and its ability to avoid tooth discolouration after 3 weeks of incubation. The results of this study confirm that TRIMIX-C even in an ex vivo model shows a higher bactericidal activity, accompanied by excellent penetration in dentinal tubules.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
