Bio-Functional Nanodiamond Restorative Materials Containing Bio-Additives: In Vitro Approach

Restorative materials in the new era aim to be “bio-active”, bio-functional and long-lasting. As a part of our continuous interest of developing functional dual action restorative materials capable of being “bio-active” functional restorative materials, we designed and evaluated several novel nano-diamond:chitosan containing hydrogels as a prototype of molecular scaffold materials capable of free radical defense action containing propolis extract (antioxidant containing material) from 3 different regions namely, Green Brazilian Propolis, Uruguan Propolis and Australian Propolis. We evaluated the physical properties, bonding to dentin as well as test the bioadhesion of the newly designed materials in order to access the suitability of these prototype materials as suitable restorative materials, evaluated total phenol capacity of the materials as well as free radical defense capacity using BSA protein model as a quick and effective in vitro model. The hydrogels were prepared as previously reported by our protocol. The physico-chemical features including surface morphology (SEM), release behaviors, stability of the antioxidant-chitosan-nanodiamond and the effect of the hydrogels on the shear bond strength of dentin were measured. Structural investigations of the reactive surface of the hydrogel are reported. Bio-adhesive studies were performed in order to assess the suitability of these designer materials. Free radical defence and performance of the materials was evaluated using BSA and Folin Ciocalteu assay. Results: Within the limitations of the study design chitosan-antioxidant hydrogels are suitable materials for functional restorative and periodontal applications in vitro. The addition of propolis extracts nano-diamond chitosan prototype delivery system had a beneficial effect on the design of the hydrogel by increasing bioadhesive properties of the newly prepared hydrogels, increasing free radical defense properties of the biomaterials as well as increasing the dentin bond strength of the newly designed hydrogels. Conclusion: The added benefits of the chitosan treated hydrogels involved positive influence on the naproxen release as well as increased dentin bond strength as well as demonstrating good antimicrobial properties and enhanced antioxidant stability. The therapeutic polymer approach described here has a potential to provide clinical benefit, through the use of “designer” adhesive restorative materials with the desired properties.