A rubber dam is a thin latex sheet that isolates the tooth from the rest of the mouth. Saliva does not get into the treatment area, so the filling bonds tightly to the tooth.
1What a rubber dam is
It is a special latex sheet. It is placed over the tooth being treated, so the tooth ends up "outside", separate from the rest of the mouth. This way the doctor works on a dry, clean area.
2Why saliva is bad for a filling
When treating caries and placing a filling, the tooth surface must stay clean and dry. Saliva and moisture in the working area weaken the bond between the filling material and the tooth.
A rubber dam keeps saliva away from the tooth, and the filling holds tightly.
3Easier for the doctor, more precise treatment
The sheet separates the tooth from the tongue, cheeks and lips. It is easier for the doctor to work on a small area and control every stage of treatment.
4When else a rubber dam is used
Rubber dams are widely used in root canal treatment, where isolating the tooth from moisture and the contents of the mouth is especially important.
So a rubber dam is not an optional extra but a tool that helps create the right conditions for quality treatment.