Comparison of strains transferred to a bone simulant among implant overdenture bars with various levels of misfit.
J Prosthodont
; 4(4): 243-50, 1995 Dec.
Article
in En
| MEDLINE
| ID: mdl-8601182
ABSTRACT
PURPOSE:
To measure and compare strains transferred to a bone simulant by screw-fastening implant overdenture bars with various levels of fit or misfit. MATERIALS ANDMETHODS:
Photoelastic resin was cast directly to two 3.75 X 13-mm Branemark fixtures (Nobelpharma USA Inc, Chicago, IL) situated 20 mm apart in a silicone mold of an edentulous mandible. Two strain-gauge rosettes were also incorporated in the resin to allow precise determination of principal stresses at two locations. Four groups of three overdenture bars with 0-, 180-, 360-, and 500-micrometer vertical gaps were fabricated. These bars were sequentially secured to the abutments with gold slot screws tightened to 10 N-cm. Strain indicator readings were recorded at a standardized time following the initial fastening of each bar. The test was repeated three times for each overdenture bar.RESULTS:
Mean principal stresses and strains at the location of the rosettes were determined. The magnitude of these stresses and strains increased significantly with each increase in gap size. Strains were several times larger mesial to the fixture than they were distal.CONCLUSIONS:
Strains are transferred to the bone when misfitting prostheses were secured. Some of the strains mesial to the fixture appeared to be unfavorable for regions of lower bone density when the groups with designed gaps were secured. These data will be compared with those in ongoing animal studies regarding the cellular response to prosthesis misfit.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Dental Prosthesis Retention
/
Dental Prosthesis Design
/
Dental Prosthesis, Implant-Supported
/
Dental Stress Analysis
/
Denture, Overlay
Limits:
Humans
Language:
En
Journal:
J Prosthodont
Journal subject:
ODONTOLOGIA
Year:
1995
Document type:
Article
Affiliation country:
Estados Unidos
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA