ANTIMICROBIAL EFFECTS OF A LIGHT CURED HYDROGEL FOR PERI-IMPLANT DISEASES

Abstract

Background: Dental implants have become a standard of care in dentistry in order to replace missing teeth. The high success rates of implant placement have been reported in the literature. However, in the last decade there is an increasing evidence of implant failure. Thus, there has been huge emphasis in the prevention, management and treatment of peri-implantitis. Periodontal pathogens such as P. gingivalis play major role in peri-implantitis. Nonsurgical and surgical intervention with adjunctive use of antimicrobials and laser disinfection to treat peri-implantitis are not always successful in complete decontamination of the pathogens. There is a need to develop minimal invasive therapies that remove pathogens and promote the regeneration of periodontal tissues. Moreover, hydrogels have found applications in dentistry for periodontal and pulpal tissue regeneration in conjunction with the nonsurgical and surgical therapies in dentistry. Currently, the Smart Biomaterials Lab is developing a piezoelectric hydrogel incorporated with barium titanate (BTO) fillers that offer antibacterial effects. The light curable hydrogel can be injected in the periodontal/peri-implant pockets to provide antimicrobial effects against periodontal pathogen. Objective: The aim of this study is to evaluate the antimicrobial effects of piezoelectric hydrogel against P. gingivalis for the treatment of peri-implantitis. Materials and methods: Two groups of biomaterials were tested. Group 1 consisted of BTO (GelMA hydrogel with piezoelectric fillers BTO), Group 2 consisted of GelMA only (hydrogel with no fillers), and control group (biofilms were grown in an empty well) called Empty well. Hydrogel samples were tested under two conditions including static and cyclic loading (1 N and 2 Hz) to activate the antibacterial effects. The antibacterial activity was evaluated by measuring metabolic activity (via MMT) and colony-forming unit. Results: the mean metabolic activity showed no statistically significant difference between BTO, GelMA and control under static and cyclic loading conditions. Log CFU of the 3 groups showed same results under static and cyclic loading condition however, the small sample size for CFU assay made it hard to obtain conclusive results. Conclusions: with the limitations of this study, there was no antimicrobial effect of BTO against P. gingivalis at magnitude 1 N and frequency of 2 Hz. Further studies will be conducted to investigate the antimicrobial effect of BTO against P. gingivalis when the magnitude is 2 N and frequency is 10 Hz for piezoelectric charge production