An investigation of possible iatrogenic damage caused by metal rubber dam clamps.

Rubber dam may be held in place over a tooth by metal clamps. It has been shown that a mismatch of contact between the clamp gripping edge and the tooth surface may be reduced to a point contact, thereby concentrating the gripping force generated by the bow of the clamp. Experiments were conducted to measure the force. Clinically realistic loading of the tooth surface by sections of the gripping edge of clamps was carried out using special apparatus. Examination by scanning electron microscopy showed that iatrogenic damage to the tooth could occur. Therefore a plea is made for clamps to be redesigned to reduce any harm.