Avoiding iatrogenic damage
Avoiding iatrogenic damage when preparing multi-surface restorations
When preparing multi-surface cavities, iatrogenic damage to the proximal surface of the adjacent tooth is common. This damage has been shown to occur in up to 60% of multi-surface preparations and is associated with a significantly increased risk of subsequent caries development.97 There are various ways to reduce this risk, including placing a matrix band around the adjacent tooth prior to cavity preparation, use of separators or wedges, or the enamel margins of the box can be prepared with hand instruments alone, as shown below.
Technique
Multi-surface cavity preparation for a mesial cavity on an upper left second premolar
Use a high-speed handpiece to prepare the cavity, leaving the proximal wall of enamel intact.
Radiograph (left) and clinical image (centre) of a carious lesion requiring a multi-surface restoration; cavity prepared with proximal wall of enamel intact (right)
Remove caries using a slow-speed handpiece.
Prepare proximal cavity margins using gingival margin trimmers only. A sharp spoon excavator can also be used.
Complete the restoration using wedges and matrix bands.
Images show removal of caries (left), gingival margin trimmers used to prepare the box (centre) and final restoration (right)