Stress on implant-supported fixed prostheses with different numbers of abutments after the application of acrylic resin.
BACKGROUND
Clinical procedures and laboratory processing techniques inevitably induce stress in the implant/abutment/prosthesis system and may have negative effects when different numbers of implants are used.


OBJECTIVE
The purpose of the study was to evaluate the tension on the abutments of implant-supported fixed prostheses and to determine the effect of the application of an esthetic veneer (acrylic resin) and the number of abutments (5 or 4).


METHODS
Four palladium-silver alloy cast bars were fabricated to simulate implant-supported fixed complete prostheses. Strain gauges were fixed on the abutments to measure the tension before and after the application of the esthetic veneer. The values of tension were measured in models with 5 or 4 abutments. Data were analyzed with a repeated measures ANOVA.


RESULTS
No statistically significant differences were found for the main factors (esthetic veneer, P=.22; number of abutments, P=.14) despite the large effect size.


CONCLUSIONS
The results of this study suggest that the tension in the abutments of an implant-supported fixed prosthesis is not affected by the application of acrylic resin veneering or by reducing the number of abutments.
Assistant Professor, Department of Prosthodontics, Pontifical Catholic University of Rio Grande do Sul, Rio Grande do Sul, Brazil. Electronic address: marina.lobato@pucrs.br.
Marina Rechden Lobato
MR
Palmeiro
Assistant lecturer, Postgraduate Program in Dentistry, Pontifical Catholic University of Rio Grande do Sul, Rio Grande do Sul, Brazil.
Leonardo Hoffmann de
LH
Barcellos
Private practice, Porto Alegre, Rio Grande do Sul, Brazil.
Marcos
M
Naconecy
Assistant Professor, Department of Prosthodontics, Pontifical Catholic University of Rio Grande do Sul, Rio Grande do Sul, Brazil.
Tomás
T
Geremia
Associate Professor, Department of Engineering, Lutheran University of Brazil, Rio Grande do Sul, Brazil.
André
A
Cervieri
Professor, Department of Prosthodontics, Pontifical Catholic University of Rio Grande do Sul, Rio Grande do Sul, Brazil.
Rosemary Sadami Arai
RS
Shinkai
D000180:Acrylic Resins / Q000737:chemistry*; D001696:Biomechanical Phenomena; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry*; D019094:Dental Prosthesis, Implant-Supported; D003801:Dental Veneers; D003830:Denture, Partial, Fixed; D017097:Electric Impedance; D006801:Humans; D008422:Materials Testing; D010165:Palladium / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D019415:Torque
D000180:Acrylic Resins; D003722:Dental Alloys; D015921:Dental Implants; D003764:Dental Materials; D012834:Silver; C040291:Lucitone; D010165:Palladium