Evaluation of a new periodontal curet. An in vitro study.

Removal of plaque and calculus from subgingival root surfaces is a fundamental aspect of periodontal therapy. A new type of periodontal curet (Gracey Curvette Sub-0) has been designed to better adapt to the root surfaces that may be encountered in periodontal pockets of incisor teeth. The new curet (test) was compared to a Gracey curet 1/2 (conventional) in their ability to remove deposits from the subgingival root surfaces of incisor teeth in an in vitro model. A dentiform model mounted on a dental chair was used with artificial gingiva, 6 mm pocket depths and subgingival root surfaces covered with black enamel paint. 2 groups of 12 hygienists used, on a timed basis, either the test or conventional curet on 4 of the incisor teeth and then switched to the alternate instrument for the remaining four incisors. The extent of surface material removal was determined using a computerized video routine. The test curet removed significantly (p less than 0.001) more of the surface material from all subgingival incisor root surfaces than the conventional curet (60.7% versus 46.3%). Both instruments were most effective at labial surfaces. The test curet was least effective at proximal surfaces and the conventional curet least effective at lingual surfaces. The greatest statistical difference between instruments was apparent at lingual surfaces of maxillary incisors and the least at mesial surfaces of mandibular incisors.