A survey of failure modes in composite resin restorations.

This study was undertaken as a first step in identifying opportunities to decrease the need for replacement of class 3, 4, and 5 composite resin restorations. Data regarding the reasons for original placement or replacement of a restoration, the age of restorations at the time of replacement, and patient/doctor factors that may be associated with a decision to place or replace a restoration were recorded by use of a cross-sectional survey. During a 2-week period 108 dentists recorded reasons for placing or replacing 1360 restorations. Of the 1360 restorations, 42.8% were classified as primary placement and 57.2% as replacement restorations. Of the primary placements 80% were categorized as being due to caries; 9.1% fracture of tooth; 8.4% other (erosion lesions were specified 94% of the time). By class, caries was the dominant cause for class 3 (96.2%); caries and other (erosion) for class 5 (77.3% and 16.4%); fracture of tooth and caries (48.9% and 40.2%) for class 4 restorations.