Page 94 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability
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CHAPTER 4
surface roughness and inclusion or exclusion of smokers t2 = 0.56 (SE = 0.093) was significant and the variability between groups remains high I2 = 99.36% (Q = 11,272.9, df = 76, p < .0001). The roughness of the surface was significant as mediating factor (QM = 7.43, df = 2, p = .024). The residual heterogeneity remained significant t2 = 0.5187 (SE = 0.0878) and the variability between groups high I2 = 99.27% (Q = 10,956.63, df = 74, p < .0001). The mediator roughness introduced a reduction in residual homogeneity of 0.09%. The inclusion of smokers in the study did not lead to a significant decrease in heterogeneity. Note that the inclusion of smokers does not mean that a research group solely consisted of smokers and that the amount of smoking was not taken into account because was seldom reported objectively.
Meta-Analysis. For studies testing differences in surface roughness using one implant design the het- erogeneity I2 between the studies was not significant (Q = 0.45, df = 2, p = .8001). The fixed effect model showed a significant difference in mean bone loss between minimally rough and moderately rough implant surfaces (Figure 4) with less bone loss for the former (z = 3.1716, p = .0015).
Figure 4: Forest plot for additional bone loss (expressed as positive value in mm) and moderately rough implant surfaces (experimental group) and minimally rough (control group)
Heterogeneity I2 =88.5% for the studies evaluating the influence of periodontal history was significant equal to and the t2 medium (66.6%) (Q = 32.55, df = 2, p=.0002). The random effects model showed a significant difference in mean bone loss between patient groups with a periodontal history and without a periodontal history (z=2.1793, p=.029) (Figure 5). When only the rough surfaces were maintained the heterogeneity I2 was no longer significant (Q = 1.76, df= 1, p=.1849). The random fixed effect model showed a significant difference with
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