Objectives: Ti-6Al-7Nb alloy has many advantageous properties over Co-Cr alloy and, therefore, has a potential to be applied to removable partial dentures (RPD). However, since its elastic modulus is approximately half of Co-Cr, the improvement of rigidity by reinforcement design is necessary for the application to major connectors (MC). Our preliminarily study showed 4 potential strengthening designs for Ti-6Al-7Nb MC, which had comparable rigidity with a conventional Co-Cr MC (0.8mm thick x 10mm width). Those included; A (0.8mm x 16mm); B (1mm x 10mm); C and D (0.8mm x 10mm, with reinforcements at the middle and at the anterior and posterior borders). The aim of this study was to examine if there is patients' preference of specific MC design.

Methods: Seven patients, (1 male and 6 females; 61.9 +/- 9.5 years) with Kennedy class I or II maxillary RPD participated in this study. Four trial major connectors (TMC) were fabricated with light cure tray resin and inlay wax for each subject. The subjects were given 2 TMC to wear, each one for 30 seconds and, were asked to select the preferred one. This was repeated 6 times in a random order and every combination was tested. The construction of the TMC and the administration of the test were performed following standardized protocols.

Results: The preference test took approximately 25-30 minutes in the clinical set up. The rank of the patients' preference was significantly different among 4 TMC (Friedman test, P<0.05). Designs A, C and D were preferred to design B (Bonferroni post-hoc, P<0.05 for each comparison).

Conclusions: The patients' preference of the MC design could be tested by this method in the clinical setup without any substantial difficulty. Thinner designs, although wider or with reinforcements, tended to be preferred to thicker design in our study subjects.

Back to the Prosthodontics Research Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)

Top Level Search