RESUMO
AIM: To assess the ex vivo effectiveness of the alternated use of 1% NaOCl and 15% citric acid in association with two instrumentation techniques for the disinfection of root canals infected with Enterococcus faecalis and Candida albicans. METHODOLOGY: Eighty human mandibular premolars with straight, oval root canals standardized to 15 mm in length were infected with a mixed culture of E. faecalis and C. albicans for 28 days. Five other teeth were used as controls and were neither contaminated nor instrumented. Specimens were divided into two groups (n = 40), according to whether the canal preparation technique used manual (K-type) or rotary (Protaper Universal) instruments. These groups were further divided into four subgroups (n = 10) according to the irrigation solution used: saline, 1% NaOCl, 1% NaOCl with alternated use of 15% citric acid and 5.25% NaOCl. Root canals were prepared with a crown-down technique until a size 50 K-file or with rotary preparation until an F5 instrument. Microbiological sampling was performed before (S1) and after (S2) the chemomechanical preparation, using sterile paper points. The specimens were split, and 0.02 g of dentine chips was collected from the root thirds to verify the presence of microorganisms in root canal walls. RESULTS: Saline and 1% NaOCl were less effective in reducing microorganisms compared with 1% NaOCl with alternated use of 15% citric acid or 5.25% NaOCl alone (P < 0.05). Both manual and rotary preparations significantly reduced microorganisms regardless of the irrigation solution used (P < 0.05). However, there was no significant difference between the canal preparation techniques (P > 0.05). CONCLUSIONS: Irrigation with 5.25% NaOCl and 1% NaOCl alternated with 15% citric acid reduced microorganisms in infected root canals significantly more than saline and 1% NaOCl.
Assuntos
Candida albicans/efeitos dos fármacos , Cavidade Pulpar/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Dente Pré-Molar/microbiologia , Ácido Cítrico/uso terapêutico , Dentina/microbiologia , Desinfecção/métodos , Desenho de Equipamento , Humanos , Preparo de Canal Radicular/instrumentação , Cloreto de Sódio , Hipoclorito de Sódio/uso terapêutico , Ápice Dentário/microbiologiaRESUMO
AIM: To detect enterococci, enteric bacteria and yeast species from the canals of teeth with primary endodontic infections before and after canal preparation and to test the antibiotic susceptibility of enterococcal strains isolated from infected root canals. METHODOLOGY: Twenty-five single-rooted teeth with pulp necrosis, intact pulp chambers and periradicular lesions were selected for study. Samples were collected from canals before and after instrumentation. Amongst isolated microorganisms from infected root canals only enterococci, enteric bacteria and yeasts were identified by biochemical tests. The in vitro antimicrobial susceptibility of isolated enterococci strains was evaluated by the Etest system. RESULTS: Microorganisms were isolated from 92% of the samples following intracoronal access, 22% were enterococci, enteric bacteria or yeast species. After biomechanical preparation, these species were no longer detected. After 7 days without intracanal dressing, 100% of the canals contained microorganisms, 52% of which were target species. However, after using paramonochlorophenol [PRP (2.0 g), Rinosoro and polyethylene glycol (400 equal parts up to 100 mL)] as an intracanal dressing for 7 days, enteric bacteria and yeasts were not detected; only enterococci were still present. All strains of enterococci were susceptible to ampicillin, but exhibited variable susceptibility to rifampin and ciprofloxacin. CONCLUSIONS: Enterococci, enteric bacteria and yeasts were present in primary endodontic infections. Enterococci, particularly Enterococcus faecalis and E. faecium were resistant to removal by root canal preparation followed by intracanal dressing.
Assuntos
Cavidade Pulpar/microbiologia , Necrose da Polpa Dentária/microbiologia , Periodontite Periapical/microbiologia , Irrigantes do Canal Radicular/farmacologia , Adulto , Infecções Bacterianas/microbiologia , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candidíase Bucal/microbiologia , Clorofenóis/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Enterococcus/efeitos dos fármacos , Enterococcus/isolamento & purificação , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Polietilenoglicóis/farmacologia , Preparo de Canal RadicularRESUMO
In the kidney, the 11beta-hydroxysteroid dehydrogenase type 2 enzyme (11betaHSD2) inactivates glucocorticoids to their inactive ketoforms and thus prevents endogenous glucocorticoids from occupying the nonselective mineralocorticoid receptor in epithelial tissues. Several mutations have been described in the 11betaHSD2 gene in the congenital syndrome of apparent mineralocorticoid excess. These mutations generate partially or completely inactive 11betaHSD2 enzymes. In the present work, we describe an already known mutation in a new patient affected by apparent mineralocorticoid excess, which results in an arginine-to-cysteine mutation (R213C) in the 11betaHSD2 enzyme. This mutation has been found in two other independent families. In vitro expression studies of this mutant provide evidence that the mutant protein is normally expressed, but its activity is abolished. The CGC-to-TGC (C-toT) transition at codon 213 can be considered a typical CpG-consequence mutation. The present finding suggests that the codon R213 of 11betaHSD2 is a hot spot for mutations in this gene, as shown by the occurrence of an R213C point-mutation in several families unrelated to each other.