Influence of Prosthetic Screw Material on Joint Stability in Passive and Non-Passive Implant-Supported Dentures
Aloísio Oro Spazzin1, *, Guilherme Elias Pessanha Henriques1, Mauro Antônio de Arruda Nóbilo1, Rafael Leonardo Xediek Consani1, Lourenço Correr-Sobrinho2, Marcelo Ferraz Mesquita1
Identifiers and Pagination:Year: 2009
First Page: 245
Last Page: 249
Publisher ID: TODENTJ-3-245
Article History:Received Date: 9/4/2009
Revision Received Date: 17/8/2009
Acceptance Date: 17/9/2009
Electronic publication date: 30/12/2009
Collection year: 2009
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
This study evaluated the influence of prosthetic screw material on joint stability in implantsupported dentures at two levels of fit.
Ten mandibular implant-supported dentures were fabricated. Twenty cast models were fabricated using these dentures. Four groups (n=10) were tested, according to the vertical fit of the dentures [passive and non-passive] and prosthetic screw materials [titanium (Ti) or gold (Au) alloy]. The one-screw test was performed to quantify the vertical misfits using an optic microscope. The loosening torque for the prosthetic screws was measured 24 hours after the tightening torque (10 Ncm) using a digital torque meter. Data were analyzed by two-way ANOVA and Tukey’s test (α=0.05).
Overall, dentures with passive fit and Ti screws resulted in significantly higher loosening torque of the prosthetic screws (p<0.05). No significant interaction was found between fit level and screw material (p=0.199). The prosthetic screw material and fit of implant-supported dentures have an influence on screw joint stability. Ti screws presented higher joint stability than Au screws and minimum of misfit should be found clinically to improve the mechanical behavior of the screw joint.