An in vivo quantitative analysis of the fit of Nobel Biocare implant superstructures
| Autor: | J A Hobkirk, P D Cheshire |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Orthodontics
Dental Implants Dental Stress Analysis Materials science Dental Impression Technique Dental prosthesis Abutment Dental Abutments Osseointegration Dental Prosthesis Retention Polyvinyl siloxane Traveling microscope Dental Prosthesis Design Torque Prosthesis Fitting Vertical direction Humans Implant Dental Prosthesis Implant-Supported Composite material General Dentistry |
| Zdroj: | Journal of oral rehabilitation. 23(11) |
| ISSN: | 0305-182X |
| Popis: | Loss of osseointegration of implant fixtures and mechanical failure of superstructures have been attributed to failure to achieve a passive fit between the superstructure and the transmucosal abutment (TMA). The fit of five mandibular superstructures, fabricated on Nobel Biocare implants, was investigated in vivo, using a polyvinyl siloxane impression material to record the discrepancies. Following sectioning of the impressions, the vertical and horizontal discrepancies were analysed at four locations using a travelling microscope. The discrepancies obtained were measured both when the gold cylinder screws were maximally tightened by hand and when tightened with a torque driver to the recommended value of 10 Ncm. The vertical discrepancies for the hand tightened abutments ranged from 0 micron to 63 microns with a mean of 14 microns. In the mechanically tightened group, the vertical discrepancies ranged from 0 micron to 130 microns with a mean of 21 microns. The horizontal discrepancies for the mechanically tightened abutments ranged from 0 micron to 140 microns with a mean of 31 microns, compared with a mean of 46 microns and range of 0 micron to 113 microns, for the hand-tightened abutments. A close fit was seldom achieved. It is concluded that considerable discrepancies existed around superstructures that had been judged to have a clinically acceptable fit. These were reduced in the vertical direction by hand tightening of the gold screws. |
| Databáze: | OpenAIRE |
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