Dimer Acid Bisphenol A Free Dental Pit and Fissure Selants

Objective: This investigation seeks to develop and evaluate potential pit and fissure sealants based on dimer acid technology using non bisphenol A type novel monomers. Other than the replacement of a possibly toxic structural component, experimental goals include increasing conversion, decreasing polymerization shrinkage, and improving the stress of common dental pit and fissure sealants, Methods: The experimental compositions were formulated with a novel non bisphenol A type dimethacrylate monomer, a dimer acid derivative (DDCDMA), 1,6-hexanediol dimethacrylate (HDDMA) or trimethylolpropane trimethacrylate (TMPTMA) and isobornyl methacrylate. Ratios of DDCDMA to HDDMA or TMPTMA were varied. Composition 1, 2 and 3 contain 20:2; 16:4 and 12:8 wt% ratios of DDCDMA/ HDDDMA while 4, 5 and 6 contain 20:2; 16:4 and 12:8 wt% ratios of DDCDMA/ TMPTMA respectively. The experimental compositions were light activated using camphorquinone/amine in 0.2/0.4wt% ratio. Final conversion degree was measured by near-infrared spectroscopy. Photo-polymerization shrinkage was determined using a linometer. Mechanical properties such as flexural strength and modulus were also measured. For comparison, all of the above tests were also performed on a control sample Bis-GMA/TEGDMA 70/30wt% and a commercially available pit and fissure dental sealant. The data was analyzed statistically by one-way ANOVA and Tukey (p<0.05), Results: Results are shown in the Table. For each series, similar letters indicate that no statistical differences were found.

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Conclusions: New pit and fissure sealant compositions have been prepared by a combination of dimer acid technology and newly developed high molecular weight non bisphenol A type monomers. In spite of the significantly higher polymerization conversion, the sealants showed significantly lower values of polymerization shrinkage and mechanical strength in the range of commercially available materials.