MICROBIOLOGICAL AND IMMUNOLOGICAL EFFECTS OF MONOMER FREE THERMOSENS AND NANO ZIRCONIA OXIDE REINFORCED DENTURE BASE RESINS ON CONTROLLED DIABETIC DENTURE WEARERS

Background: The overall success of denture base resins depends on both mechanical behaviour and biocompatibility, especially in the rehabilitation of diabetic patients. The growth and nourishment of microorganisms is enhanced in diabetes mellitus specially in presence of dentures resulting in denture stomatitis. This study was prompted to assess the microbiological growth and the development of salivary immunoglobulin A (s-IgA) in relation to newly introduced denture base materials used in the rehabilitation of diabetic patients.
Materials and Methods: Forty eight completely edentulous patients were selected and divided into two groups: group (A), which included controlled diabetic patients and group (B) included non-diabetic patients. Each group was further divided into four sub groups according to the denture base material. Sub group I, patients were received thermoplastic VertexTM ThermoSens denture bases; sub group II, patients were received heat cure acrylic resin dentures reinforced with nano zirconia oxide particles (nano-ZrO2); sub group III, patients were received conventional heat cure acrylic resin dentures; where sub group VI, patients were received conventional heat cure acrylic resin dentures relined with self-cure acrylic resin. For each participant, non-stimulated saliva samples were collected before denture insertion, and one, two and three months after wearing dentures. Samples were inoculated and incubated both aerobically and anaerobically on selective media for Streptococcus mutans, Lactobacilli and Candida. Then, isolated microorganisms were identified, the characteristic colony forming units per millilitre (CFUs/ml), were calculated and the salivary immunoglobulin A level was measured by Enzyme-linked immunosorbent assay (ELISA).
Results: The results revealed increase in the CFU values of Candida, Streptococcus mutans, Lactobacilli and the level of salivary immunoglobulin A in all the assessed patients following denture insertion. However, significant lower values were evident in patients rehabilitated with ThermoSens and nano-ZrO2 reinforced bases compared to heat cure acrylic and self-cure relined bases. Significant increase in CFU values and level of s-IgA were found in diabetic compared to non-diabetic patients after insertion of all denture bases. Conclusion: ThermoSens and nano-ZrO2 reinforced denture bases showed less microbial growth and salivary immunoglobulin A level compared to heat cure and self-cure relined bases in both controlled diabetic and non-diabetic patients, hence, more biocompatible.
Keywords: Thermoplastic polyamide, Vertex ThermoSens, Reinforced acrylic, Zirconia oxide nanoparticles, Diabetes mellitus, Candida, Oral bacteria, Salivary Immunoglobulin A.