Influence of different rubber dam application on intraoral temperature and relative humidity.

The purpose of this study was to investigate the effect of type of rubber dam and application method on the moisture exclusion effect. The intraoral temperature and relative humidity were compared among various moisture exclusion appliances. Various dry field techniques were applied to 5 subjects and intraoral temperature and relative humidity measured 5 min after placing a digital hygro-thermometer in the mouth. The relative humidity was 100% in all subjects when moisture was excluded by means of cotton rolls alone. When only tooth 36 was exposed, relative humidity was significantly lower with latex, urethane, or 3-dimensional sheets than with cotton rolls alone, and was similar to the level of humidity in the room. When a local rubber dam was used, the relative humidity was significantly higher than the indoor humidity (p<0.05). No significant differences were noted in the intraoral temperature or relative humidity between exposure of 4 teeth and 1 tooth, but variation in the relative humidity was more marked in 4- than in 1-tooth exposure. The creation of an air vent did not influence the moisture exclusion effect. These results suggest that the rubber dam isolation technique excludes moisture to a level equivalent to the humidity in the room when only a single tooth is exposed, but the moisture exclusion effect may be inconsistent when several teeth are exposed.