Comparative in vitro effectiveness of closed root debridement with fine instruments on specific areas of mandibular first molar furcations. I. Root trunk and furcation entrance.

The purpose of this study was to compare curets with a small blade to slim ultrasonic inserts on their efficacy in removing artificial deposits from the root trunk and furcation entrance areas of mandibular molars using an in vitro model simulating a clinically closed root debridement approach. The study was conducted on 100 artificial mandibular first molars (50 right side and 50 left side) with anatomical roots. Root trunks, furcation entrances, and furcation areas of each molar were colored by a coat of black model paint. The teeth were fixed in a custom acrylic model and maintained in a firm position by modified acrylic occlusal splints. The root areas were covered with a heavy rubber dam imitating gingival tissue. The model was attached to a mannequin and mounted on a dental chair. Fifty molars (25 right, 25 left) were instrumented with the experimental curets and an equivalent number of molars with the ultrasonic inserts. The instrumentation was carried out by one experienced operator, spending 4 minutes on each molar. The instrumented areas were individually analyzed to determine the percentage of deposits remaining, using a computerized imaging routine system. One-way analysis of variance was conducted to test for differences between both types of instruments. Results revealed that the curets were significantly more efficient (P < 0.01) than the ultrasonic inserts in removing paint from both root trunks and furcation entrances. These findings should be corroborated in a clinical study to determine the potential value of the instruments tested during initial therapy or supportive care of involved mandibular furcations.