Abstract
BACKGROUND: We hypothesized that wearing a mouthguard may affect salivary flow and composition. Therefore, we investigated the impact of mouthguard use on saliva secretion rate and some salivary constituents under different jaw activities. METHODS: This was a randomized crossover experimental study including 13 volunteers. Saliva samples of the volunteers were collected and analysed in four different experimental conditions: without mouthguard with relaxed jaw (RJ), without mouthguard after repetitive jaw contractions (JC), with mouthguard with relaxed jaw (MG-RJ) and with mouthguard after repetitive jaw contractions (MG-JC). RESULTS: Saliva secretion rate was significantly higher in the condition MG-JC compared to all other conditions (P < 0.01). Total protein concentration and Mucin 5B (MUC5B) levels in saliva did not differ significantly between the four experimental conditions. Immunoglobulin A (IgA) concentrations were significantly lower in the condition MG-JC compared to all other conditions (P < 0.01). CONCLUSION: Mouthguards increase saliva flow rate, compared to not wearing a mouthguard, and jaw contractions enhance this effect compared to a relaxed jaw. Wearing a mouthguard during active jaw activity reduced the concentration of salivary IgA.