The use of casein in sport mouthguards: microbiological and ecological variations in oral cavity

Sport mouthguards have the potential to become a microbial reservoir, produce oral and systemic diseases and cause negative changes in the oral cavity. The aim of this study was to monitor oral environmental changes caused by casein and sport-mouthguard in vivo, through clinical, salivary and bacterial markers of young athletes. Forty-eight active young athletes in different disciplines were selected and analysed at different times: baseline (T0); after three months of casein application on the mouthguard (T1); and after six months of application (T2). The product used was GC Tooth Mousse®. At T0, clinical monitoring was performed and the following parameters were recorded: Decay-Missing-Filled Teeth (DMFT) index, Plaque index (PL+) and Gingival Bleeding (BOP+). Saliva-Check Buffer GC® and Saliva-CheckMutans GC® salivary tests were then performed. At T0 the athletes demonstrated DMFT 0.03±0.01. PL value was positive in 100% of subjects at T0, T1, and T2. The BI value was always negative. At the three time-points, a significant change in baseline hydration values was observed; baseline viscosity was normal in 50% of cases while it increased in the remaining 50% at T0; it was normal and constant at T1 and T2. The value of the baseline pH underwent an not statistically significant increase at T1 (7.6±0.08) while remaining constant at T2. The amount of saliva produced after 5-min stimulation ranged significantly and gradually from T0 to T1 and T2, with a statistically significant difference. Plaque indicator tests highlighted that at T0 a plaque with a pH of 6.0±0.5 prevailed; at T1 it was 6.25±0.75 while at T2, pH was equal to 6. Tests for the detection of S. mutans resulted constant in all subjects at the various observation times, resulting in 67% of patients in whom S. mutans was present. The application of casein, within custom-made ethylene- vinyl acetate (EVA) mouthguards, positively influences salivary flow, the increase of pH values, the amount of stimulated saliva and the buffering capacity of the athlete, improving their state of oral health, which is negatively affected by the use of common mouthguards.