Abstract
PURPOSE: This prospective crossover clinical study evaluated the effectiveness of different moisture control methods on intraoral humidity and examined the influence of external environmental humidity. MATERIALS AND METHODS: Forty adult participants (31 females, 9 males; mean age 36.6 ± 11.3 years) were enrolled. Intraoral relative humidity was measured above anterior and posterior teeth under four randomized conditions: control (mouth breathing), rubber dam isolation, vacuum-assisted isolation (ZOO), and saliva ejector. External humidity was recorded simultaneously and categorized as high (≥60%) or low (60%). RESULTS: Both rubber dam isolation and vacuum-assisted isolation significantly reduced intraoral humidity compared with the saliva ejector and control. Under low external humidity, rubber dam and vacuum-assisted isolation achieved the lowest intraoral humidity (all P 0.001). Under high external humidity, all methods reduced humidity compared with control, but vacuum-assisted isolation remained significantly more effective than the rubber dam and saliva ejector. External humidity showed a strong correlation with intraoral humidity in the rubber dam group (ρ up to 0.77, P 0.001). CONCLUSION: Moisture control methods differ in their ability to reduce intraoral humidity, with rubber dam and vacuum-assisted isolation providing the most effective reduction. However, high external humidity significantly increases intraoral humidity regardless of the isolation method, indicating that clinicians should consider both the isolation strategy and environmental conditions when aiming to minimize intraoral humidity.