Influence Of Implant Location On The Clinical Outcomes Of Implant Abutments: A Systematic Review And Meta-analysis

Objectives: To compare the failure events and incidence of complications of different abutment materials in anterior and posterior regions.Failure was defined as complete loss of the abutment requiring replacement by a new abutment.Methods: Electronic search using Pub Med/MEDLINE and Google Scholar complemented with hand searches were performed with specific search terms,searches were restricted to publications in English language between January 2006 and March 2016.Results: 863 and 1264 implants were inserted in the anterior and posterior regions respectively in a total of 1529 patients.No titanium abutments failed in anterior or posterior regions.On the other hand 1.6% of zirconia abutments failed in anterior region and 1.5%failed in posterior regions.Technical complications occurred mostly in the posterior region and mostly involving zirconia abutments.Meta–analysis was only possible for zirconia abutments failure due to considerable heterogeneity of studies and outcome variables.No significant difference in failure rate was found between anterior and posterior zirconia abutments [Risk ratio(RR): 1.53;95% confidence interval: 0.49 to 4.77;p=0.47].Conclusion: The systematic review and meta-analysis shows similar outcome of different abutment materials when used in anterior or posterior regions in terms of failure events,biological and esthetic complications.The only significant finding was the increased incidence of technical complications in the posterior region mostly involving zirconia abutments.Abutments screw loosening was the most common technical complication.