Effect of Coated Surfaces influencing Screw Loosening in Implants: A Systematic Review and Meta-analysis
Dhanraj M Ganapathy, Abinaya Kannan, Suresh Venugopalan
Citation Information :
Ganapathy DM, Kannan A, Venugopalan S. Effect of Coated Surfaces influencing Screw Loosening in Implants: A Systematic Review and Meta-analysis. World J Dent 2017; 8 (6):496-502.
Introduction: The abutment screw loosening has been a
common clinical mishap affecting the success of the implant
in the long run. With repeated insertion and removal of the
implant abutment screw during fabrication of the restoration,
frictional wear at the microscopic level in the screw threads
had been reported.
Aim: To assess the effectiveness of screw coating in
minimizing abutment screw loosening in dental implants in
Results: A database search yielded a total of 14 articles out
of which 8 were excluded based on the title and abstracts not
relevant to the topic of our interest and 6 were included based on
the core data. The six articles were reviewed, and four articles
were consolidated to perform the meta-analysis. All the four
studies showed a similar expression of outcome measure; the
detorque values were expressed in Ncm.
The χ2 = 144.71, df = 3, p < 0.00001, and I2 = 98%. Hence, a
Random Effect model with 95% confidence interval was chosen
for meta-analysis. The overall effect observed in the metaanalysis
was Z = 0.36, p = 0.72, and no statistically significant
differences were observed between the coated and noncoated
screws with respect to detorque values.
Conclusion: This meta-analysis inferred that there is no difference
between the coated and noncoated screws with respect
to screw loosening.
Clinical significance: Noncoated screws are equally effective
as coated screws with respect to abutment loosening in
endosseous implants. Hence, the additional cost and technique
sensitivity incurred with powdered screws may not drastically
improve the rate of failure due to screw loosening.