Adhesive interaction of orthodontic plate appliances with mixed oral microbiota

Relevance. The presence of an orthodontic appliance within the oral cavity enhances the formation of supplementary retention sites for the adhesion of microorganisms. The porosity of acrylic base materials, coupled with their limited polishability, further predisposes the surface to contamination by a biofilm of microorganisms. Evaluating the capacity of materials to attract bacterial adherence to their surfaces represents a crucial phase in patient treatment.Purpose. This study aims to perform a comprehensive clinical and laboratory investigation into the adhesive properties of orthodontic plate appliances crafted from various dental plastics concerning the mixed oral microbiota.Materials and methods. In vitro research was conducted, focusing on both removable and non-removable orthodontic plate appliances featuring a base composed of dental plastics (referred to as Sample 1 and Sample 2). The study included 80 orthodontic patients, comprising 50 children aged 8 to 12 years with removable appliances and 30 children aged 8 to 10 years with non-removable plate appliances. Patients were categorized into two groups based on the material of their appliances: the first group, pertaining to those with removable appliances (Subgroup 1A – Sample 1, 25 individuals, and Subgroup 1B – Sample 2, 25 individuals); the second group, comprising individuals with non-removable appliances (Subgroup 2A – Sample 1, 15 individuals, and Subgroup 2B – Sample 2, 15 individuals).Results. In the in vitro investigations, it was observed that the average colonization of removable plates was 100 times lower (4.5 log CFU/ml) compared to non-removable plates (5.5 log CFU/ml; p < 0.05). The average colonization of plates composed of plastic (Sample 2) demonstrated a significant reduction, approximately 200 times (4.0 log CFU/ml), compared to plates made of plastic (Sample 1) (6.0 log CFU/ml; p < 0.05). Upon evaluating the overall colonization of the oral cavity, bacterial growth ranged between 106-7 CFU/ml in patients with appliances made of plastic Sample 1, whereas in patients with appliances made of plastic Sample 2, the range was limited to 103-4 CFU/ml (p < 0,05).Conclusion. The statistical analysis reveals a significant disparity in the adhesive activity of microorganisms to orthodontic plate appliances constructed from materials of distinct production origins, with notably lower adherence observed on smoother surfaces (specifically those made of plastic Sample 2). This underscores the importance of meticulous consideration for the polishability properties inherent in the materials utilized in the manufacturing of orthodontic appliances.