The effect of magnification on the iatrogenic damage to adjacent tooth surfaces during class II preparation

Objectives. To determine the amount of damage to adjacent surfaces during cavity preparation of approximal box-cavities by using either no magnification or an individually adapted surgical telescope. Materials and Methods. Nine dentists prepared in a mannequin head 4 approximal (class II) box-cavities without magnification using a high speed handpiece with lighting from a dental unit. At least 2 months later the test was repeated with a surgical telescope system with integrated light. The degree of damage the 72 adjacent surfaces suffered was determined. Results. The average time needed to prepare one cavity was 14.9 min without and 18.3 min with magnification (p=0.01). Altogether, 29.7% of adjacent area were damaged when no surgical telescopes were used and 34.5% when surgical telescopes were applied (p>0.05). When the mesial-facing and distal-facing surfaces were analysed independently a statistically significant increase of damage was found on distal surfaces (p=0.03) when using surgical telescopes. Seventy surfaces (=97%) had a preparation trauma. Conclusions. Surgical telescopes do not decrease damage of adjacent tooth surfaces.