There is a vast difference in the amount of evidence supporting the various implant systems included in this meta-analysis presented by researchers from the Cochrane Oral Health Group. We caution readers against generalizing the results particularly to those implant systems backed by only one to two studies with only one year follow-up and no long-term outcomes data. It is not logical, scientific or otherwise, that these newer market entry implants are put on the same level as implants such as those with the TiUnite surface which have over ten years of follow-up.
One well known weakness of such a meta-analysis of several small studies is that it cannot predict the results of a larger study. With 38 different implant types with highly diverse geometries, surfaces, prosthetic superstructures and clinical protocols applied – several which are no longer in use – there are many variables. The meta-analysis dilutes any potential effect of a single relevant implant surface or implant characteristic in clinical practice today.
This report analyses weak studies, a majority of which are highly biased (15 out of 27), and almost all are inconclusive. Grouping these to form a conclusion about all moderately rough surface implants is meaningless. When looking at the individual studies, almost none were powered sufficiently to detect any differences between implant systems. Based on the quality of evidence, readers were cautioned against applying these results to practice.
The meta-analysis reports a 20 percent lower risk of peri-implantitis with machined implants based on four studies; however, the single study with TiUnite implants (2007) showed no peri-implantitis in either group. The remaining three studies were from 2002 or earlier; thus this analysis contributes nothing new. Experts in 2012, (Karolinska Institutet Working Group, EJOI Supplement 2012:5) agreed that focusing on implant surface is short sighted as there are multiple factors that can contribute to bone level change such as smoking, plaque, immune factors, surgical trauma, grinding teeth etc.
The meta-analysis reports patients with machined implants were more than two and a half times as likely to have an early failure. From long-term retrospective studies with TiUnite, failures have not caught up with those “early” failures seen with machined implants after up to nine years. The meta-analysis method excludes retrospective studies which represent the bulk of the latest research in the field of implant dentistry. Looking to these studies, they tend toward much longer-term follow-up and much larger numbers of patients included, not afforded by prospective randomized trials which typically end after three to five years. Furthermore, this leaves much of the longer-term, albeit retrospective data, showing better bone levels with TiUnite ignored.
The only study showing significant difference in outcomes by implant geometry with the same surface was the NobelActive implant compared to NobelSpeedy Groovy. The results are not surprising considering the outstanding bone level change of a mere -0.2 mm during the first six months and a 0.3 mm gain from implant placement by year three with NobelActive (Kolinski 2013). NobelActive is a major advance in implant design. NobelSpeedy Groovy shows normal bone remodeling according to accepted criteria and it offers bi-cortical anchorage. Implant selection is based upon the clinical situation: both implants are important options for clinicians and patients.
All dental implants are not the same. There are big differences between proven implant systems and those which succumb to lower standards. At Nobel Biocare we are committed to the highest standards of scientific evidence and believe this dedication to evidence-based dentistry is more important in our industry than ever. Our implants and solutions have proven themselves in all types of clinical studies – many of them following the more demanding one-stage protocol with immediate loading. TiUnite is one of the most clinically researched implant surfaces on the market, with over 850 scientific publications, 279 clinical references covering 42,000 implants in 13,000 patients.