Page 88 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

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not mention the standard deviation of bone loss were excluded because calculation of proportions of bone loss was impossible.124,147,160,163,165,167,171,175,176,182
Figure 2, A–C summarize the bone loss in relation to the follow-up time including all 87 studies of this review. The overall mean bone loss was 1.01 mm (95% CI 1.00 – 1.03; SD 0.89 and ranging between -0.94 and 3.47 mm). In the total material, 49% of the implants lost more than 1 mm bone, 18% of the implants lost more than 2 mm, and 5% lost more than 3 mm bone. A distinction was made per implant surface roughness and shown in Figure 3, A–C for rough, moderately or minimally rough surfaces and Figure 3D for the mixed/unknown surfaces. The mean bone loss, standard deviation and proportion of implants losing more than 1, 2, or 3 mm bone is given per study. Table 5 shows per surface roughness the mean bone loss pointing to 1.04 mm, 1.01 mm, and 0.86 mm for the rough, moderately, and minimally rough surfaces, respectively. Between minimally and moderately or rough there was a statistically significant difference, but this was not observed between moderately and rough surfaces. Taking bone loss above 2 mm as arbitrary cut-off point reflecting a higher chance for peri-implant disease, the proportion was 20% for rough (Figure 3A), 18% and for moderately rough (Figure 3B), and 14% for minimally rough (Figure 3C).
Unfortunately among the 87 selected papers for this review, there was only one prospective study that compared machined minimally rough Bra˚nemark implants with moderately rough TiUnite implants in conjunction with immediate loading.147 The TiUnite surface yielded a superior cumulative implant survival of 95.5% compared to 85.5% in the machined group but the corresponding 1.4 and 1.7 mm bone loss was not statistically different. Unfortunately, this study did not report the standard deviation of the mean bone loss and hence could not be included in prevalence calculation.
There are four retrospective studies in this review that compared implants with comparable design, often from the same implant brand, but with different surface roughness.117,154,177 Vandeweghe and colleagues117 evaluated 197 Southern Implants with either smooth or minimally rough surface after 10 to 21 years of loading with the baseline at time of implant placement. Multivariate analysis demonstrated that the rougher surface yielded more peri-implant bone loss than the smooth surface implant. Prevalence of bone loss above 3 mm, as reported in
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