Grant: Operating Grant

Tooth-coloured resin-composite based restorations are currently the most popular restorative materials in the dental field; their applications include direct and indirect restorations of the teeth, dental adhesives and cements. Bacterial penetration and proliferation along the tooth-resin dental restoration interface contributes to postoperative sensitivity, recurrent caries and pulp inflammation. Recurrent caries at the tooth-restoration interface margin is regarded as the major cause of restoration failure. Therefore, the success of a resin- based dental restoration is highly dependent on the formation, and the maintenance of impermeable seal to bacterial penetration to prevent ingress of bacteria and bacterial by-products. Our group developed a laboratory model, consists of continues media system in combination with fluorescent dyes and confocal laser microscopy, optimizing the conditions for bacterial microleakage and biofilm formation studies of dental plaque bacteria. This system provides a valid laboratory model which is physiologically relevant to pathogenic intra oral conditions. Using this system, the PIs' research group has revealed that human saliva induced biodegradation, compromising the restoration-tooth marginal interface, leading to bacterial penetration and proliferation along the restoration-tooth interfacial gap, as well as reducing the bond strength between the restoration and the tooth. The model developed by the PIs allows for testing of different strategies to inhibit degradation of the bonded interface, with the potential to increases its resistant to bacterial invasion and proliferation, ultimately leading to increase in the restorations service life. This model is novel to the dental health care community and its clients, and merits attention since it has the potential to change the way composite resin materials adhesives are formulated and tested.