South African Dental Journal
versão On-line ISSN 0375-1562
ASWAL, G S e NAIR, C K. Effects of various parameters of alumina air abrasion on the mechanical properties of low fusing feldspathic porcelain laminate material. S. Afr. dent. j. [online]. 2015, vol.70, n.4, pp. 150-155. ISSN 0375-1562.
RATIONALE: Alumina air abrasion is a commonly used surface treatment for porcelain veneers. This in vitro study determined the influence of various parameters of alumina air abrasion on the mechanical properties of porcelain. OBJECTIVES: To ascertain the influence of alumina particle size, air stream delivery pressure and distance from the nozzle, on surface roughness, material loss and bi-axial flexural strength of low fusing feldspathic porcelain and to determine the optimum combination of these factors. MATERIALS AND METHODS: 95 specimens of feldspathic ceramic measuring 1mm in thickness by 15 mm in diameter were prepared. Alumina air abrasion was carried out with varying parameters viz three different particle sizes (50μm, 110μm, 250μm), two different pressures (20psi, 50psi) and three different distances (1cm, 2cm, 5cm. RESULTS: The various combinations which produced the greatest and the least effects on the test parameters were identified and the results were statistically analysed using the factorial ANOVA test. CONCLUSIONS: The combination of 50μm alumina particle size, 20psi air stream pressure and either 2cm or 5cm distance between the nozzle and the ceramic surface produced optimum surface roughness with reduced impact on the flexural strength of the ceramic.
Palavras-chave : Feldspathic ceramic; alumina air abrasion; surface roughness; material loss; flexural strength.