Photopolymerizable dental composites have complex processing conditions and multi-component formulations that affect the final properties. Combinatorial screening is a useful approach for evaluating multiple properties of the composites. A single test substrate was fabricated to support multiple formulations that possess a continuous gradient in the degree of conversion. This methodology was used successfully to evaluate mechanical properties and damage response as a function of filler type, filler content, and irradiation. Degree of conversion, surface roughness, modulus, hardness, scratch deformation, and cytotoxicity were quantified using near infrared spectroscopy, laser confocal scanning microscopy, depth sensing indentation scratch, and cell viability assays, respectively. The current platform allows for direct comparison of various properties on the same sample. It was found that the total filler content, the presence of nanofiller, and the irradiation time/intensity affected the final properties of the composites, although the dominating factor for improvement was the degree of conversion.
Citation: Acta Materialia
Pub Type: Journals
dental composite, nanoindentation, cytotoxicity, instrumented indentation scratch testing, combinatorial