RESUMO
PURPOSE: Achieving optimal moisture inside the root canal is a challenge during bonding of fiberglass posts. This study evaluated the effect of different moisture patterns on the push-out bond strength (PBS) and nanoleakage (NL) of fiber posts bonded to the root canal of two simplified etch-and-rinse adhesives. MATERIALS AND METHODS: The roots of 72 human premolars were endodontically prepared and divided into 6 groups according to the combination of the main factors: adhesive (Ambar and Adper Single Bond 2) and moisture (dry, wet, and overwet). The posts were cemented and after 1 week, the roots were cross sectioned into 6 disks. Two disks each were obtained from the cervical, middle, and apical thirds, and the PBS test was carried out (0.5 mm/min; n = 8). The NL was evaluated by scanning electron microscopy after the immersion of specimens in 50% silver nitrate (n = 4). The failure pattern was examined on all debonded specimens. Data were analyzed by three-way repeated measures ANOVA and Tukey's test (5%). RESULTS: For both adhesives, higher PBS values and lower NL were observed in the wet groups, and lower PBS and higher NL in the dry group. In general, the overwet condition showed intermediate results. CONCLUSIONS: The root dentin walls should be left slightly moist before performing fiber post cementation procedures.
Assuntos
Cimentação/métodos , Materiais Dentários/química , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Vidro/química , Técnica para Retentor Intrarradicular/instrumentação , Colagem Dentária , Cimentos Dentários/química , Corrosão Dentária/métodos , Infiltração Dentária/classificação , Adesivos Dentinários/química , Dessecação , Humanos , Teste de Materiais , Metacrilatos/química , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Coloração pela Prata , Estresse Mecânico , Propriedades de Superfície , Fatores de Tempo , Ápice Dentário/ultraestrutura , Dente não Vital/patologia , Água/químicaRESUMO
The aim of this study was to evaluate the antimicrobial activity of Uncaria tomentosa (Willd.) DC (cat's claw) against Enterococcus faecalis, Staphylococcus aureus, and Candida albicans. Suspensions with 10(8) cells/ml of each microorganism were plated in triplicate on Mueller-Hinton agar. Wells in the agar were made and filled with 2% chlorhexidine (CHX) gel, 2% cat's claw (CC) gel, 2% CHX+CC, and 1% hydroxyethylcellulose (NAT) gel. Inhibition halos were measured after 24 h at 37°C and differences were analyzed using one-way ANOVA. The mean diameter of the microbial growth inhibition zones of 2% CHX+CC against the tested microbial strains ranged from 21.7 to 33.5 mm. This was the most effective substance against E. faecalis and C. albicans, followed by CHX and CC. Against S. aureus, CHX+CC, CHX, and CC showed similar antimicrobial activity (P > 0.05). The results indicate that all the investigated compounds had antimicrobial activity against microorganisms frequently found in infected root-filled teeth.
