The effects of gamma and microwave sterilization on periodontological grafts

Abstract

Guided tissue regeneration (GTR) and guided bone regeneration (GBR) biomaterials play an important role in periodontal procedures in recent years. A guided tissue-regeneration membrane performances as a block stopping fast-growing soft tissue from raiding space required to be filled with new bone,So, it permit osseous regeneration prior to soft tissue migration into the area of interest. Degradable polymeric Sterilization of grafts as regenerative biomaterials is an essential topic in medicine due to their direct contact with human blood. As a result, the sterilization method applied to these materials has to be reliable beside being cost-effective and cause a minor change in the grafts' structure and effectiveness. In this study, gamma irradiation as an accepted sterilization method and microwave as a new sterilization industry approach were evaluated. In this evaluation, widely used dental collagen-based biomaterials from human and animal sources were exposed to different gamma radiation level used in the experiments (2, 4, 5, 10, 25, and 50 kGy). Also, microwave sterilized grafts as a novel sterilization method were evaluated at 1,2,3,and 4 min of irradiation. Although free radicals are not expected after microwave irradiation, grafts were evaluated by ESR after irradiation by microwave to consider this radiation as a sterilization method. Microwave irradiation did not cause major differences in the samples' ESR spectra. This situation continue even up to 8 min of irradiation. The radiolytic intermediates formed in the samples due to gamma and microwave irradiation were considered by Electron Spin Resonance (ESR) spectroscopy. The characteristic features of the free radicals induced by gamma and microwave radiation in biomaterials were detected. Also, the radical stability biomaterials were studied for a long time interval. Based on results, HL1 is considered an excellent radiosensitive material, and PDG3 is regarded as a good ratio resistive material among the other examined samples. It was also concluded that ESR spectroscopy is a suitable technique in providing indispensable detailed spectroscopic findings for GTR/GBR biomaterials exposed to microwave and gamma radiation sterilization at different doses.