A novel method to obtain microtensile specimens minimizing cut flaws.
J Biomed Mater Res B Appl Biomater
; 78(1): 7-14, 2006 Jul.
Article
em En
| MEDLINE
| ID: mdl-16292761
Cutting procedures conventionally used for microtensile specimens' preparation induce mechanical stress and attrition, leading to cracks in dental structure. Enamel is mainly affected due to its high module of elasticity and brittleness. As an alternative to the conventional diamond saw, a diamond wire was used for cutting. The two techniques were compared in efficacy in the preparation of two different sample shapes. Forty human molars, flattened in dentin or enamel, were used for sample preparation. After bonding procedures, resin block was built incrementally. Half of the teeth were cut using a diamond disc and the other half using a diamond wire, obtaining slabs and stick-shaped specimens. Slabs were then shaped to obtain hourglass samples. Five samples from each subgroup were randomly selected for Scanning electron microscopy (SEM) analysis. Remaining samples underwent microtensile test and the results were analyzed, including/excluding premature failures (pf), with three-way ANOVA and Tukey test, performed separately, by substrate. On dentin, only the exclusion of pf showed a significant higher bond strength values than when pf were included (p < 0.05); however, on enamel, all factors (equipment, shape and including/excluding pf) had a significant effect on bond strength (p<0.05). The most remarkable finding from SEM was the incidence of specimens' cracks and defects when diamond blade was used. Scratches and cracks in the hourglass-shaped specimens were also detected. In both cases, enamel was more affected than dentin.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Manejo de Espécimes
/
Diamante
/
Dente Molar
Limite:
Humans
Idioma:
En
Revista:
J Biomed Mater Res B Appl Biomater
Assunto da revista:
ENGENHARIA BIOMEDICA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos