Available online 10 July 2018
Abstract
Statement of problem
Cement-retained implant-supported
prostheses
eliminate screw loosening and enhance esthetics. However,
retrievability and the possibility of removing extruded excess cement
(EEC) have been problematic.
Purpose
The
purpose of this systematic review was to analyze the effects of
modifying the screw access channel (SAC) on the amount of EEC and the
retention of cement-retained implant-supported prostheses.
Material and methods
PubMed,
Web of Science, Scopus, and Google Scholar databases were searched with
appropriate key words. Related titles and abstracts published up to
June 2017 were screened and selected on the basis of defined inclusion
criteria. Full texts of all studies were read and subjected to quality
assessments. After the initial search, 1521 articles were included in
the study. Of these, 11 studies were subjected to
critical appraisal, and 10 of them were reliable enough in methodology to be systemically reviewed.
Results
All the studies were
in vitro
and described a total of 260 specimens. According to the interpreted
results, closed SACs caused lower retention with a higher amount of EEC,
whereas open SACs caused the reverse. Also, as the abutment height
decreased, retention decreased.
Conclusions
Extending
the crown’s margin into the SAC, leaving the SAC open, and using
internal vents in the SAC space are possible methods of modifying the
SAC to gain higher retentive values. Also, the use of internal vents in
the SAC system and open or partially filled SAC space reduce the amount
of EEC.
Comments