A natural compound found in grape seed extract could be used to strengthen dentine, according to new research.

Published in the Journal of Dental Research and conducted at the University of Illinois at Chicago College of Dentistry, the research describes how grape seed extract has the potential to strengthen composite resin fillings, allowing them to last longer.

The extracts, says research author Ana Bedran-Russo, can increase the strength of the dentine, which comprises the majority of the calcified extracellular tissue of teeth, forming the layer just beneath the hard external enamel.

Interface reinforcement

Dentine is mostly made of collagen, the main structural protein in skin and other connective tissues.

Resins have to bind to the dentine, but the area between the two, or the interface, is a weak point, causing restorations to breakdown, Bedran-Russo said.

‘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 dentine.

‘The interface can be changed through the use of new natural materials.’

Secondary caries and margin breakdown are the most frequent causes of failed adhesive restorations, Bedran-Russo said.

Despite numerous advances in dental restorative materials, degradation of the adhesive interface still occurs.

Bedran-Russo has discovered that damaged collagen can repair itself with a combination of plant-based oligomeric proanthocyanidins — flavonoids found in most foods and vegetables — and extracts from grape seeds.

Interlocking the resin and collagen-rich dentine 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 minimising tooth loss,’ Bedran-Russo said.

One of the possible benefits of using grape seed extract is that it prevents tooth decay, she said.

Further research

Bedran-Russo and Guido Pauli, 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.

Co-authors on the Journal of Dental Research study are Ariene Leme-Kraus, Berdan Aydin, Cristina Vidal, Rasika Phansalkar, Joo-won Nam, James McAlpine, Pauli and Shao-nong Chen, all of UIC.

The research was funded by the National Institute of Dental and Craniofacial Research, one of the National Institutes of Health in the US.