Evaluation of bacterial leakage rate at the interface of ITI fixtures and ITI, DIO and OSSTEM solid abutments

 Background and Objective: One of
the most concerns about the use of implant treatments is bacterial leakage
between the fixture and abutment at the connection. The aim of this study was
to evaluate the bacterial leakage rate at the interface of ITI fixtures and
ITI, DIO and OSSTEM solid abutments.  Materials and Methods: Thirty ITI
fixtures were divided into three groups (n=10) based on the abutment used. In
the first group, 10 solid ITI abutments, in the second group, 10 solid DIO
abutments, and in the third group, 10 solid OSSTEM abutments with similar
length and diameter were screwed into fixtures. Fixtures and abutments were
assembled and allowed to incubate in a solution of Streptococcus faecalis
(SF) for 5 days. In each group, two additional fixtures and two abutments were
selected and divided into two subgroups. In the negative-control subgroups,
abutments were not connected to fixtures and were placed into normal saline
solution. In the positive-control subgroup, abutments were not connected to
fixtures but were subjected to the same bacterial solution. After disconnection
of fixtures and abutments under sterile condition, abutments and fixtures were
placed in 1ml of normal saline solution and were vortexed for 30 sec. Then,
0.01 ml of each vortexed solution was cultured under appropriate conditions for
2 days. The CFUs (colony forming unit) were counted and recorded for each
abutment and fixture. Results: The average of CFUs for
each abutment and fixture counted in the first group was 13.6 and 20, in the
second group was 21.9 and 28.9, in the third group was 26.2 and 35.9, in positive
control subgroup was 152.3 and 178.3, and in negative-control subgroup was 0
and 0, respectively. There were not statistically significant differences
between the first and second groups but the leakage rate was statistically
different between first and third groups. Conclusion: The results of the
present study demonstrated that compatibility of DIO solid abutments on ITI
fixtures are acceptable but it is not the case for OSSTEM solid abutments and
the use of these abutments on ITI fixtures is not recommended.