Effect of time in hardness test on artificially demineralized human dental enamel

• Autor(a) principal: Marsillac, Mirian de Waele Souchois de
• Data de Publicação: 2008
• Outros Autores: Delbem, Alberto Carlos Botazzo [UNESP], Vieira, Ricardo de Sousa
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://www.bibliotecadigital.unicamp.br/document/?code=32643&opt=4; http://hdl.handle.net/11449/70280
• topic: Dental enamel; Hardness tests; Tooth demineralization

A cross-sectional microhardness (CSMH) test was carried out in human dental enamel exposed to a demineralizing solution in order to evaluate two different times of indentation in sound tissue and artificially induced caries. Twenty caries-free extracted human molars had one of their smooth surfaces sectioned and the enamel surface was isolated with nail polish except for an area of 6 mm2. These specimens were submitted to artificially induced enamel caries on a lactate buffer containing 0.1 ppm fluoride (F) during 28 days. All specimens were bisected to create groups A and B in which CSMH test was performed employing a Knoop indenter with a 25g load for 5 or 10 s, respectively. Student's paired t-test (p<0.05) was used to determine statistically significant differences between group A and B in 7 depths. There were no significant differences between any of the analyzed depths. Since the present experiment showed no significant difference when comparing indentations made with a 25 g load during either 5 or 10 s in different depths, this method can be used with either one of the time intervals tested without compromising a CSMH test on artificially demineralized human enamel.