Thayse Yumi Hosida1, Alberto Carlos Botazzo Delbem1, Leonardo Antônio Morais1, João Carlos Silos Moraes2, Cristiane Duque1, José Antônio Santos Souza1, Denise Pedrini3,4. 1. Department of Pediatric Dentistry and Public Health, School of Dentistry, Araçatuba, São Paulo State University (UNESP), Araçatuba, SP, Brazil. 2. Department of Physics and Chemistry, São Paulo State University (UNESP), Ilha Solteira, SP, Brazil. 3. Department of Surgery and Integrated Clinic, School of Dentistry, Araçatuba, São Paulo State University (UNESP), Araçatuba, SP, Brazil. denise.pedrini@unesp.br. 4. Disciplina de Clínica Integrada, Faculdade de Odontologia de Araçatuba - UNESP, Rua José Bonifácio 1193, Araçatuba, SP, 16015-050, Brazil. denise.pedrini@unesp.br.
Abstract
OBJECTIVES: To evaluate the effects of hexametaphosphate microparticles (mHMP) or nanoparticles (nHMP) incorporated in glass ionomer cement (GIC) on antimicrobial and physico-mechanical properties, fluoride (F) release, and enamel demineralization. MATERIAL AND METHODS: HMP solutions were obtained at concentrations of 1, 3, 6, 9, and 12%, for screening of antimicrobial activity. Next, mHMP or nHMP at 6, 9, and 12% were incorporated into a resin-modified GIC and the antibacterial activity was evaluated. The resistance to diametral tensile and compressive strength, surface hardness, and degree of monomer conversion as well as F and HMP releases of GICs were determined. Furthermore, specimens were attached to enamel blocks and submitted to pH-cycling, and mineral loss was determined. Parametric and non-parametric tests were performed, after checking data homoscedasticity (p < 0.05). RESULTS: HMP solutions at 6, 9, and 12% demonstrated the best antibacterial activity. GIC containing HMP showed better antibacterial effects at 9 and 12% for nHMP. Regarding F and HMP releases, the highest levels of release occurred for groups containing 9 and 12% nHMP. With the increase in HMP concentration, there was lower mineral loss. However, the incorporation of mHMP or nHMP in GIC reduced values of physico-mechanical properties when compared to the control GIC. CONCLUSIONS: nHMP improves antimicrobial activity and fluoride release, and decreases enamel demineralization, but reduces the physico-mechanical properties of GIC. CLINICAL RELEVANCE: The association of GIC/HMP could be an alternative material for patients at high risk for dental caries and could be indicated for low-stress regions or provisional restorations.
OBJECTIVES: To evaluate the effects of hexametaphosphate microparticles (mHMP) or nanoparticles (nHMP) incorporated in glass ionomer cement (GIC) on antimicrobial and physico-mechanical properties, fluoride (F) release, and enamel demineralization. MATERIAL AND METHODS:HMP solutions were obtained at concentrations of 1, 3, 6, 9, and 12%, for screening of antimicrobial activity. Next, mHMP or nHMP at 6, 9, and 12% were incorporated into a resin-modified GIC and the antibacterial activity was evaluated. The resistance to diametral tensile and compressive strength, surface hardness, and degree of monomer conversion as well as F and HMP releases of GICs were determined. Furthermore, specimens were attached to enamel blocks and submitted to pH-cycling, and mineral loss was determined. Parametric and non-parametric tests were performed, after checking data homoscedasticity (p < 0.05). RESULTS:HMP solutions at 6, 9, and 12% demonstrated the best antibacterial activity. GIC containing HMP showed better antibacterial effects at 9 and 12% for nHMP. Regarding F and HMP releases, the highest levels of release occurred for groups containing 9 and 12% nHMP. With the increase in HMP concentration, there was lower mineral loss. However, the incorporation of mHMP or nHMP in GIC reduced values of physico-mechanical properties when compared to the control GIC. CONCLUSIONS:nHMP improves antimicrobial activity and fluoride release, and decreases enamel demineralization, but reduces the physico-mechanical properties of GIC. CLINICAL RELEVANCE: The association of GIC/HMP could be an alternative material for patients at high risk for dental caries and could be indicated for low-stress regions or provisional restorations.