Page 194 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

CHAPTER 8
■ IMPLANT-RELATEDFACTORS
The systematic review and meta-analysis of Study II focussed on the long-term effect of implant surface roughness on peri-implant bone stability. Only 3 out of the 87 included studies were appropriate for inclusion in the meta-analysis.26-28 The result showed a significant difference in the long-term mean bone loss between minimally rough versus moderately rough and minimally rough versus rough implant systems. However, there was no significant difference between moderately and rough surfaces.
Shortly after the publication of Study II, Donati and co-workers published a 20-year follow-up of an RCT evaluating minimally rough and moderately rough implant surfaces.29 Their results showed no statistically significant difference in mean bone level change between the two implant surfaces. A more detailed analysis of the results showed that 10% of the moderately rough implants lost more than 3 mm bone compared to 0% of the minimally rough implants. The authors reported a peri-implantitis incidence of respectively 16% and 6%. Another systematic review that evaluated the effect of implant collar surface on marginal bone loss,30 revealed less bone loss for rougher implant systems. However, 10 out of the 12 studies were short term (less than five years in between follow-up). The only study with 10 years of follow-up showed less bone loss for the implants with a smooth collar compared to the implants with a rough collar. Moreover, the authors stated that their results needed to be interpreted with caution, due to confounding factors in the included papers.
As can be seen, more research is required to confirm the effect of implant surface roughness on peri-implant bone stability. However, the implant-industry did not wait for this research confirmation but recently developed a hybrid dental implant designs. This hybrid dental implant combine the presumably positive effect of minimally rough surface on bone stability and less susceptibility to develop peri- implantitis.31 These benefits were confirmed in several Cochrane reviews.32,33 The moderately rough surface is known to yield a greater bone-to-implant contact area, leading to faster osseointegration. Therefore, Study III compared a commercially available implant with an experimental hybrid implant in a split-mouth design, correcting for inter-individual variability, to test bone and soft tissue stability. Both implants were from the same brand and all design features of the implant were
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