Objectives: Bisphenol-A (BPA) is suspected to be an endocrine disrupter. Current polymeric dental materials are based on BPA derivatives, e.g. Bisphenol-A Diglycidylether Methacrylate (Bis-GMA) which may leach out unreacted monomers and its degradation products. Consequently, the present work deals with BPA-free alternatives, for potential use in dental polymer-based materials.
Methods: Commercially available fourteen oligomers for dental matrices were studied together with the materials from natural resources: commercially available sugar based vinyl macromer and synthesized novel monomer - tri-methacrylate-monomer of cholic acid (CAME) as Bis-GMA replacement in the dental adhesives, sealants and composites formulations. Various photoinitiators compatibility and hydroxyapatite addition to the experimental formulations were analyzed as well. Compressive, Flexural, Shear Bond Strength, Water Sorption, Solubility, Light Curing Time tests were conducted according to relevant ISO standards. FT-IR spectroscopy analysis was carried out to determine the Degree of Conversion of the Bis-GMA free matrices containing fillers. Volumetric Shrinkage was evaluated utilizing Archimedes Principle. All data was statistically analyzed by the analysis of variance (ANOVA) method,
at a significance level set at p < 0.005.
Results: Hexafunctional aromatic urethane acrylate (HArUA) and aliphatic urethane methacrylate (AUMA) were suitable to replace Bis-GMA in dental adhesives, sealants, composites; their physical, mechanical, adhesive properties excelled in all formulations. Following table summarizes properties of the two most promising light cure dental composite formulations
(standard deviation is ±10%).
Conclusions: Bis-GMA can be substituted by HArUA and AUMA oligomerswithout sacrificing physical and mechanical properties of the final dental polymeric adhesives, sealants and composites utilizing various fillers and photoinitiator systems.
