Author(s)

Victoria Tamara Perchyonok, Shengmiao Zhang, Nicolaas J. Basson, Sias Grobler, Theunis Oberholzer, Ward Massey

Oral and Dental Research Institute, Faculty of Dentistry, University of the Western Cape, Cape Town, South Africa.
School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia.
School of Material Science and Engineering, East China University of Science and Technology, Shanghai, China.

Restorative materials in the new era aim to be “bioactive” and long-lasting. The purpose of the study was to design and evaluate novel chitosan hydrogels containing melatonin and/or propolis (antioxidant containing material), nystatin (antifungal), naproxen (pain relieve medication) and combinations thereof (chitosan-H-melatonin, chitosan-H-melatonin-naproxen, chitosan-H-propolis, chitosan-H-propolisnaproxen, chitosan-H-naproxen-propolis-melatonin, Chitosan/Propolis/Nystatin, Chitosan/Melatonin/Propolis/Nystatin, Chitosan/Propolis/BSA/Nystatin, Chitosan/Melatonin/BSA/Nystatin) as functional additive prototypes for further development of “dual function restorative materials”, to determine their effect on the dentin bond strength of a composite, to evaluate stability of the encapsulated antioxidants as well as evaluate antimicrobial properties of the selected group of “designer” functional materials. Materials and Methods: The above mentioned hydrogels were prepared by dispersion of the corresponding component in glycerol and acetic acid with the addition of chitosan gelling agent. The surface morphology (SEM), drug-polymer solid state interaction (FT-IR spectroscopy), released behaviours (physiological pH and also in acidic conditions), stability of the therapeutic agent-antioxidant-chitosan and the effect of the hydrogels on the shear bond strength of dentin were also evaluated. Results: The release of naproxen confers the added benefit of synergistic action of a functional therapeutic delivery when comparing the newly designed chitosan-based hydrogel restorative materials to the commercially available products alone. Neither the release of naproxen or the antioxidant stability was affected by storage over a 6-month period. The hydrogel formulations have a uniform distribution of drug content, homogenous texture and yellow colour (SEM study). All chitosan dentin treated hydrogels gave significantly (P < 0.05; non-parametric ANOVA test) higher shear bond values (P < 0.05) than dentin treated or not treated with phosphoric acid. Conclusion: The added benefits of the chitosan treated hydrogels involved a 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.

Therapeutic Polymers; Adhesives; Chitosan, Hydrogels; Propolis; Melatonin; Naproxen; Antimicrobial; Dentin Bonding; Antioxidants; Bioactive

Perchyonok, V. , Zhang, S. , Basson, N. , Grobler, S. , Oberholzer, T. and Massey, W. (2013) Insights into chitosan based gels as functional restorative biomaterials prototypes: In vitro approach. Open Journal of Stomatology, 3, 22-30. doi: 10.4236/ojst.2013.39A004.