PENGARUH KEDALAMAN UNDERCUT GIGI PEGANGAN DAN TIPE BAHAN CENGKERAM TERMOPLASTIK NILON TERHADAP KEKUATAN RETENSI GIGI TIRUAN SEBAGIAN LEPASAN Co-Cr KOMBINASI NILON

Abstract

Clasp is a component of RPD that serves as a retention. Nylon thermoplastic is one of clasp material, that combined with a metal frame RPD when using. Nylon thermoplastic has high flexibility, so that it can be placed at a depth greater undercut. The aim of this study was to determine the effect of type of material for nylon thermoplastic clasp and the depth of teeth undercut against the retentive force of RPDs.
Research carried out by using 24 pieces of nylon thermoplastic clasp type Lucitone FRS (USA) and Valplast (USA), with the depth of undercut were 0.5 mm and 0.75 mm. Retention force measurements performed by placing clasp on the master model
in the form of the canines, then pulled up off by Universal Testing Machine. The data were then analyzed with two way ANOVA.
Research resulted that mean value of retentive force from Lucitone FRS clasp was 4.49 N, on the other hand value of Valplast clasp was 2.2 N. Mean value of thermoplastic retentive force with 0.5 mm undercut depth was 2.69 N, meanwhile value of 0.75 mm undercut depth was 3.9 N. Statistic analysis resulted that type of clasp material nylon thermoplastic and the depth of the undercut affects on retention force (p <0.05), whereas the interraction of type of clasp material nylon thermoplastic and the depth of the undercut does not affect on retention force (p> 0.05). The conclusion in this study was nylon thermoplastic clasp and
undercut depth could affect to retention force.