Retention of adhesive cement on the tooth surface after crown cementation.

STATEMENT OF PROBLEM: Adhesive cements increase crown retention, but it is unknown if traces of cement remain undetected on the tooth surface after clinical removal of excess cement, which could exacerbate plaque retention. PURPOSE: This study measured the surface area, volume, mean depth, and maximum depth of a resin composite and a compomer luting cement left adherent on the tooth surface after removal of excess cement, as judged clinically. METHODS AND MATERIAL: Four groups of specimens (n = 48) were prepared for full coverage crowns: group AC bonding alloy with chamfer finish line, group G gold alloy with chamfer finish line, group PC porcelain with a chamfer finish line, and group PS porcelain with a shoulder finish line. Two profiles of the mesial and distal surfaces of the teeth were carried out: (1) tooth with crown seated but not cemented and (2) tooth with the crown cemented in place. Two cements and 2 methods of cement removal were studied. RESULTS: A 4-way analysis of variance for cement, crown type, method of removal, and tooth surface morphology showed that significantly greater volumes and mean depth, but not surface areas, of resin composite cement remained adherent than compomer cement (P<.05). Among crown types, significant differences were found for cement volume (group G>AC, G>PC, G>PS), cement surface area (group AC>PC, G>PC, G>PS), and maximum cement depth (group G>AC). There was no significant difference between the 2 methods of cement removal. Significantly larger surface areas and maximum depths of cement were retained on the anatomically grooved mesial surface of the maxillary first premolars than on the ungrooved distal surface. CONCLUSION: Subclinical cement retention occurred after crown cementation, which was influenced by cement, crown type, and tooth surface morphology but not method of cement removal.