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Influence of prosthetic screw material on joint stability in passive and non-passive implant-supported dentures.

Spazzin AO, Henriques GE, de Arruda Nóbilo MA, Consani RL, Correr-Sobrinho L, Mesquita MF - Open Dent J (2009)

Bottom Line: Data were analyzed by two-way ANOVA and Tukey's test (alpha=0.05).No significant interaction was found between fit level and screw material (p=0.199).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.

View Article: PubMed Central - PubMed

Affiliation: Department of Prosthodontics and Periodontics, Dental School of Piracicaba, State University of Campinas, 901 Avenue Limeira, Piracicaba, SP 13414-903, Brazil.

ABSTRACT

Objectives: This study evaluated the influence of prosthetic screw material on joint stability in implantsupported dentures at two levels of fit.

Methods: 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 (alpha=0.05).

Results: 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.

No MeSH data available.


Metal matrix and disposition of the abutment analogs.
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Figure 1: Metal matrix and disposition of the abutment analogs.

Mentions: A metal matrix was fabricated and five conical abutment analogs with platform diameter of 4.1 mm (Micro-unit; Conexão Prostheses Systems, São Paulo, SP, Brazil) were fixed to it using transversal screws. The disposition of the abutment analogs (A, B, C, D and E) used in this study simulates a common case of five implants placed between mental foramens, arranged in an arc mode, with 10-mm inter-implant spaces (Fig. 1). A master cast was then fabricated using a splinted impression technique to allow the waxing of ten prosthetic frameworks with calcinable cylinders (Conexão Prostheses Systems) and bar wax cylinders (Wax wire 4.0; Dentaurum, Pforzheim, Germany). The free ends were standardized at a 10-mm distal extension. The frameworks were then cast in cobalt-chrome alloy (Dentaurum) using the lost-wax casting technique. Heat-polymerized acrylic resin (Clássico, São Paulo, SP, Brazil) and artificial teeth made of acrylic resin (Vipi Plus; VIPI, Pirassununga, SP, Brazil) were used as veneering material. The size and volume of the dentures were controlled using a silicone matrix (Zeta Labor; Zhermack, São Paulo, SP, Brazil).


Influence of prosthetic screw material on joint stability in passive and non-passive implant-supported dentures.

Spazzin AO, Henriques GE, de Arruda Nóbilo MA, Consani RL, Correr-Sobrinho L, Mesquita MF - Open Dent J (2009)

Metal matrix and disposition of the abutment analogs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2819699&req=5

Figure 1: Metal matrix and disposition of the abutment analogs.
Mentions: A metal matrix was fabricated and five conical abutment analogs with platform diameter of 4.1 mm (Micro-unit; Conexão Prostheses Systems, São Paulo, SP, Brazil) were fixed to it using transversal screws. The disposition of the abutment analogs (A, B, C, D and E) used in this study simulates a common case of five implants placed between mental foramens, arranged in an arc mode, with 10-mm inter-implant spaces (Fig. 1). A master cast was then fabricated using a splinted impression technique to allow the waxing of ten prosthetic frameworks with calcinable cylinders (Conexão Prostheses Systems) and bar wax cylinders (Wax wire 4.0; Dentaurum, Pforzheim, Germany). The free ends were standardized at a 10-mm distal extension. The frameworks were then cast in cobalt-chrome alloy (Dentaurum) using the lost-wax casting technique. Heat-polymerized acrylic resin (Clássico, São Paulo, SP, Brazil) and artificial teeth made of acrylic resin (Vipi Plus; VIPI, Pirassununga, SP, Brazil) were used as veneering material. The size and volume of the dentures were controlled using a silicone matrix (Zeta Labor; Zhermack, São Paulo, SP, Brazil).

Bottom Line: Data were analyzed by two-way ANOVA and Tukey's test (alpha=0.05).No significant interaction was found between fit level and screw material (p=0.199).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.

View Article: PubMed Central - PubMed

Affiliation: Department of Prosthodontics and Periodontics, Dental School of Piracicaba, State University of Campinas, 901 Avenue Limeira, Piracicaba, SP 13414-903, Brazil.

ABSTRACT

Objectives: This study evaluated the influence of prosthetic screw material on joint stability in implantsupported dentures at two levels of fit.

Methods: 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 (alpha=0.05).

Results: 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.

No MeSH data available.