Essop A R, Salt S A, Sykes L M, Chandler H D, Becker P J
Department of Prosthetic Dentistry, School of Oral Health Sciences, University of the Witwatersrand, P.O. Wits, 2050, Johannesburg.
SADJ. 2000 Dec;55(12):672-7.
Retention of a partial denture depends on the amount of undercut engaged on an abutment tooth and the flexibility of the clasp. Flexibility is influenced by clasp length and the denture base material. Titanium clasps are purported to have greater flexibility than cobalt-chromium cast clasps which should enable them to engage deeper undercuts or be used where shorter clasp arms are needed such as on premolar teeth. This study investigated the flexibility of cast titanium clasps with three commonly used cobalt-chromium clasps through comparative measurements of their tip deflections and yield strengths. The results showed that the titanium clasps were significantly (P < 0.05) more flexible than the cobalt-chromium clasps. However, all four materials were found to be flexible enough to engage an undercut of 0.25 mm without exceeding their yield strengths.
局部义齿的固位取决于基牙上倒凹的利用量以及卡环的柔韧性。柔韧性受卡环长度和义齿基托材料的影响。据称钛制卡环比钴铬铸造卡环具有更大的柔韧性,这应使它们能够利用更深的倒凹,或用于需要较短卡环臂的部位,如前磨牙。本研究通过比较测量三种常用钴铬卡环和铸造钛卡环的尖端挠度和屈服强度,来研究铸造钛卡环的柔韧性。结果表明,钛制卡环比钴铬卡环的柔韧性显著更高(P < 0.05)。然而,发现所有四种材料都具有足够的柔韧性,能够利用0.25mm的倒凹而不超过其屈服强度。