Microwave Disinfection: Cumulative Effect of Different Power Levels on Physical Properties of Denture Base Resins

Autor(es)

Senna, Plinio M. ^[1] ; Da Silva, Wander Jose ^[1] ; Faot, Fernanda ; Del Bel Cury, Altair Antoninha ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Prosthodont & Periodontol, Piracicaba - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PROSTHODONTICS-IMPLANT ESTHETIC AND RECONSTRUCTIVE DENTISTRY; v. 20, n. 8, p. 606-612, DEC 2011.
• Citações Web of Science: 10

Resumo

Purpose: This study evaluated the cumulative effects of different microwave power levels on the physical properties of two poly(methylmethacrylate) (PMMA) denture base resins. Materials and Methods: Eight sets of four PMMA specimens each (two polymerized in a water bath and two using microwave energy) were immersed in beakers containing 200 ml of distilled water. Each beaker was subjected to microwave irradiation for 3 minutes at a power level of 450,630, or 900W. The surface roughness, surface hardness, linear stability, flexural strength, elastic modulus, impact strength, and fractographic propertieswere evaluated after either 6 or 36 simulated disinfection cycles. The data were statistically analyzed using ANOVA and the Tukey post hoc test (alpha = 0.05). Results: The polymerization method did not influence any property (p > 0.05) except linear stability. The surface roughness (p < 0.001) and hardness (p = 0.011) increased after 36 irradiation cycles at 630 or 900 W. The resin polymerized using microwave energy exhibited greater linear distortion (p = 0.012), and there was a cumulative effect on linear stability for both resins (p < 0.001). No significant change (p > 0.05) was observed in flexural strength; however, the elastic modulus decreased (p = 0.008) after 36 disinfection cycles. The impact strength and crack propagation angles displayed no significant differences (p > 0.05). Conclusion: Within the limitations of this study, it can be concluded that microwave disinfection at 450 W to 630 W for 3 minutes is safe for PMMA. (AU)

• Processo FAPESP: 07/06482-6 - Desinfecção de próteses dentais removíveis por energia de microondas: Efetividade e efeitos sobre a resina acrílica
• Beneficiário: Plinio Mendes Senna
• Modalidade de apoio: Bolsas no Brasil - Mestrado