Degradation of dental resin composites during intra-oral wear

Dental resin composites have become an integral part of modern dentistry and used worldwide to restore missing tooth structures, to modify tooth color and anatomical contour, and to enhance aesthetics and function. The dentist should be aware that, the aggressive complexity of the oral environment can degrade resin composites, which can be observed as a change in physicochemical properties during intra-oral wear.Effects of the oral environment on resin composites are determined by the interaction of various oral-degradative factors including mechanical, physical, chemical and biological factors with time as an overruling factor. All these different factors make the lifetime of composite restorations in the oral environment difficult to predict. During intra-oral wear, the oral-degradative factors work in synergy on the degradation mechanism. However, little is known about the way these factors work together. In this PhD project, we successfully demonstrated that the composition of oral biofilms in combination with the type of composite is one of the determining factors in the degradation of the composite as determined by a color change. Accordingly, we offer recommendations that are helpful to: (1). Manufacturers - to consider the potentially harmful effect of external and internal oral-degradative factors on the degradation of resin composites, with the challenge to take care of a better biochemical stability and a less adhesive composite for the cariogenic microbiome. (2) Researchers - to establish a proper model and analytical methods to study composite degradation. (3) Clinicians - to take into consideration material selection and awareness of restoration longevity.Dental resin composites have become an integral part of modern dentistry and used worldwide to restore missing tooth structures, to modify tooth color and anatomical contour, and to enhance aesthetics and function. The dentist should be aware that, the aggressive complexity of the oral environment can degrade resin composites, which can be observed as a change in physicochemical properties during intra-oral wear.Effects of the oral environment on resin composites are determined by the interaction of various oral-degradative factors including mechanical, physical, chemical and biological factors with time as an overruling factor. All these different factors make the lifetime of composite restorations in the oral environment difficult to predict. During intra-oral wear, the oral-degradative factors work in synergy on the degradation mechanism. However, little is known about the way these factors work together. In this PhD project, we successfully demonstrated that the composition of oral biofilms in combination with the type of composite is one of the determining factors in the degradation of the composite as determined by a color change. Accordingly, we offer recommendations that are helpful to: (1). Manufacturers - to consider the potentially harmful effect of external and internal oral-degradative factors on the degradation of resin composites, with the challenge to take care of a better biochemical stability and a less adhesive composite for the cariogenic microbiome. (2) Researchers - to establish a proper model and analytical methods to study composite degradation. (3) Clinicians - to take into consideration material selection and awareness of restoration longevity