Dentsply Cavitron Diamond Inserts provide improved efficacy in removing calculus from furcations. A total of 60 extracted human mandibular molar teeth had artificial calculus applied to the furcations, then were randomly treated with either sharp universal Gracey curettes (HAND), a plain ultrasonic TFI-10 tip in a cavitron instrument (CAV), or one of 2 diamond-coated cavitron instruments (TFI-10 fine-grit [FIN] and TFI-10 medium-grit [MED]). When the time needed to completely clean the furcations was evaluated, MED was the fastest, followed by FIN, CAV, and HAND, respectively. All of the powered instruments were faster than hand curettes with regard to effective in vitro calculus removal in furcations. The use of these types of instruments would reduce the time required to perform periodontal surgery and might improve regenerative therapy.