Dynamics of different ion release from denture-base acrylic resins and their mechanical properties after the addition of bioactive materials

BACKGROUND: The denture-base acrylic resins used by partially edentulous patients can cause local demineralization of teeth. Alkali ions released from the bioactive materials that were added to acrylic resins can increase the pH of the oral environment and slow down the demineralization process. AIM OF THE STUDY: This study aimed to create a new denture-base acrylic resin that can release ions. MATERIALS AND METHODS: A total of 222 samples with different fillers (calcium hydrogen phosphate, hydroxyapatite, two kinds of bioactive glasses, and a product obtained by reaction between bioactive glass formed from glass ionomer cement and polyacrylic acid) were prepared for the study. All the materials were tested for mechanical properties and their use as phosphate donors for 3 weeks. The measurements were presented as mean ± SD error of the mean. Data were analyzed by two-way analysis of variance, with a p-value of <0.05 as statistically significant. RESULTS: Acrylic resins obtained after the addition of a small quantity of bioactive materials (2.5–5%) showed similar mechanical properties (such as flexural strength and Izod impact resistance) as non-filled material. However, the hardness of the modified materials was higher compared to pure poly (methyl methacrylate). Samples modified with materials released phosphate ions for a short period. The materials that were identified to be most promising as an ion source were samples containing 5% calcium hydrogen phosphate (p < 0.01). CONCLUSIONS: Based on the results, it can be concluded that denture-base acrylic resins resulting after the addition of different bioactive precursors have improved mechanical properties and can release ions to the oral environment for a short period.