Amalgam is easier to use and less costly than composite resin in fillings, and it can last 10 to 15 years or more. Composite resin fillings are more aesthetically pleasing since they can be colored to match the patient’s teeth, but they only last 5 to 7 years. Now, the University of Illinois at Chicago (UIC) College of Dentistry has found a natural compound in grape seed extract that could be used to strengthen dentin and increase the lifespan of composite resin fillings.
Resins have to bind to dentin, but the interface between them is a weak point and causes restorations to break down, according to Ana Bedran-Russo, DDS, MS, PhD, associate professor of restorative dentistry. In fact, secondary caries and margin breakdown are the most frequent causes of failed adhesive restorations, she added, and despite numerous advances in dental materials, degradation of the adhesive interface still occurs.
“When fillings fail, decay forms around it and the seal is lost. We want to reinforce the interface, which will make the resin bond better to the dentin,” Bedran-Russo said. “The interface can be changed through the use of new natural materials.”
Dentin is mostly made of collagen. Bedran-Russo has discovered that damaged collagen can repair itself with a combination of plant-based oligomeric proanthocyanidins, which are flavonoids found in most foods and vegetables, and extracts from grape seeds. Interlocking the resin and collagen-rich dentin provides better adhesion and does not rely on moisture.
“The stability of the interface is key for the durability of such adhesive joints and, hence, the life of the restoration and minimizing tooth loss,” Bedran-Russo said.
One of the possible benefits of using grape seed extract is that it prevents tooth decay, Bedran-Russo said. She and Guido Pauli, PhD, professor of medicinal chemistry and pharmacognosy in the UIC College of Pharmacy, recently collaborated on another study that showed extract from the root bark of Chinese red pine trees has similar properties to the grape seed extract.
The study, “Biostability of the Proanthocyanidins-Dentin Complex and Adhesion Studies,” was published by the Journal of Dental Research.