Anodised or turned dental implants?

Data sourcesAn electronic search without time or language restrictions was undertaken using several databases: PubMed/Medline, Web of Science and the Cochrane Oral Health Group Trials Register and ongoing clinical trials. Manual searches were performed in dental implant related journals and reference lists of identified studies, and relevant reviews were scanned for possible additional studies.Study selectionEligibility criteria included human clinical studies, either randomised or not, comparing implant failure rates, MBL and/or post-operative infection in any group of patients receiving turned (machined) and anodised-surface (TiUnite) implants, both from the same implant manufacturer.Data extraction and synthesisThe titles and abstracts of all reports identified through the electronic searches were read independently by the three authors. For studies appearing to meet the inclusion criteria, or for which there were insufficient data in the title and abstract to make a clear decision, the full report was obtained. Disagreements were resolved by discussion between the authors. Quality assessment of the studies was executed according to the Newcastle-Ottawa scale (NOS), which is a quality assessment tool used when observational studies are also included in systematic reviews.ResultsThirty-eight publications were included. The results suggest a risk ratio =2.82(95%CI, 1.95 - 4.06, P < 0.00001) for failure of turned implants when compared to anodised-surface implants. Sensitivity analyses showed similar results when only the studies inserting implants in maxillae or mandibles were pooled. There were no statistically significant effects of turned implants on the MBL (mean difference [MD]=0.02, (95%CI, 0.16 - 0.20; P = 0 82) in comparison to anodised implants. The results of a meta-regression considering the follow-up period as a covariate suggested an increase of the MD with the increase in the follow-up time (MD increase 0.012 mm year 1), however, without a statistical significance (P = 0.813). Due to lack of satisfactory information, meta-analysis for the outcome 'post-operative infection' was not performed.ConclusionsWithin the limitations of the existing investigations, the present study suggests that turned implants have a statistically higher probability to fail than anodised-surface implants, regardless of whether the implants were placed in maxilla or mandible. There were no statistically significant effects of turned implants on the MBL when compared with anodised implants. A comparison of post-operative infection between the implant types was not possible, due to lack of sufficient information. The reliability and validity of the data collected, the limitations of the quality assessment tool and the potential for biases and confounding factors are some of the shortcomings of the present study. The results have to be interpreted with caution due to the presence of several confounding factors in the included studies.