Force-to-failure of a simulated implant-supported complete fixed dental prosthesis reinforced with glass fiber.
BACKGROUND
The joint adjacent to the cantilevered section of an implant-supported complete fixed dental prosthesis (ICFDP) undergoes the most stress because of force magnification in this area, making it more prone to mechanical failure.


OBJECTIVE
The purpose of this in vitro study was to evaluate the ultimate force-to-failure distal to the terminal implant of a simulated ICFDP reinforced with glass fiber compared with that of a conventionally fabricated prosthesis.


METHODS
Thirty ICFDPs with bilateral distal cantilevers were fabricated and divided into 3 groups: the not-reinforced (NR) group was processed without reinforcement, the glass-fiber-reinforced (GR) group was reinforced with glass fiber, and the titanium-reinforced (TR) group was fabricated with a titanium bar. The specimens were screw-retained onto a standardized mandibular model with 4-implant analogs embedded in acrylic resin. All groups were processed using heat-polymerized acrylic resin. After 24 hours, the cantilevers were loaded to fracture (in N) 10 mm away from the center of the most distal analog under compression at a crosshead speed of 1 mm/min. Statistical analysis of data was performed using a 1-way analysis of variance (ANOVA) model by using Tukey B post hoc comparison procedures (α=.05).


RESULTS
Data revealed the mean fracture load of the NR group was 1073 ±108 N, 1400.75 ±123.53 N for the GR group, and 1652.78 ±274.14 N for the TR group. Statistically significant differences (P<.05) were found among all 3 groups. Comparison between the left and right side of the tested prostheses did not show any significant differences (P=.595).


CONCLUSIONS
A fiber-reinforced ICFDP provides better biomechanical properties than an unreinforced one, which may allow its longer-term use as an interim ICFDP. However, the titanium bar ICFDP still provided the best resistance to fracture.
Former graduate student, Advanced Prosthodontics, Herman Ostrow School of Dentistry, University of Southern California Los Angeles, Los Angeles, Calif; and Private practice, Mexico City, Mexico. Electronic address: jackgoldbergdds@gmail.com.
Jack
J
Goldberg
Assistant Professor, Division of Restorative Sciences, Herman Ostrow School of Dentistry, University of Southern California Los Angeles, Los Angeles, Calif.
Gelareh
G
Ronaghi
Assistant Professor, Division of Restorative Sciences, Herman Ostrow School of Dentistry, University of Southern California Los Angeles, Los Angeles, Calif.
Jin-Ho
JH
Phark
Associate Clinical Professor, Advanced Prosthodontics, Herman Ostrow School of Dentistry, University of Southern California Los Angeles, Los Angeles, Calif.
Sajid
S
Jivraj
Ralph and Jean Bleak Professor of Restorative Dentistry, Director of Advanced Prosthodontics, and Director of Implant Dentistry, Herman Ostrow School of Dentistry, University of Southern California Los Angeles, Los Angeles, Calif.
Winston
W
Chee
D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D005898:Glass; D013314:Stress, Mechanical
C009753:fiberglass