Intraoral humidity during operative procedures.

Results of dentine adhesion studies are influenced by many factors such as intrinsic and extrinsic dentine wetness. Relative air humidity and temperature are extrinsic environmental factors whose influence on dentine bonding capability is not precisely known. It was the aim of this study to gain an understanding of these factors as present in the mouths of patients and as influenced by several variables. In six different experiments the influence of application of a rubber dam, high and low relative humidity in the dental surgery, nose and mouth breathing and tooth drying was investigated. The results show that without application of a rubber dam there was no statistically significant difference in temperature for the variables nose and mouth breathing and tooth drying (mean 27.7 +/- 1.5 degrees C). Only the difference in relative air humidity of the dental surgery was statistically significant. With the application of a rubber dam the relative air humidity and temperature were essentially the same as the dental surgery conditions. It is concluded that without rubber dam the intraoral environment in which bonding procedures are to be performed is comparable with a high humidity climate such as that of Central Africa or the South Pacific.