# Virtual Zirconia Implants Replace Titanium Implants?
## 5 Soft Tissue Reaction  
In natural dentition, the consensus is that there are not necessarily specific keratinized gingiva dimensions to maintain periodontal health under good oral hygiene [78; 79; 80]. On the other hand, the peri-implant soft tissue is different from that around a natural tooth. In implants, as its surface is directly attached to the bone, there are not periodontal fibers anchoring in the bone, and collagen fibers run parallel to the implant surface without direct \begin{table}
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**Reference** & **Aim** & **Main Results** & **Conclusions** \\ \hline \multirow{5}{*}{\begin{tabular}{c} [PERSON] et al., \\ 2008 [73] \\ \end{tabular} } & SR with seven animals’ & The mean bone–implant contact percentage & \begin{tabular}{c} Zirconia implants may \\ become an alternative to \\ titanium implants, but cannot \\ currently be recommended for \\ routine clinical use, as no \\ long-term clinical data \\ are available. \\ \end{tabular} \\  & SR with 14 clinical studies and at least 1 year follow up & The overall survival rate of zirconia was 92\% & \begin{tabular}{c} Zirconia ceramics could \\ potentially be the alternative \\ to titanium for a non-metallic \\ implant solution. \\ \end{tabular} \\  & \begin{tabular}{c} SR with 14 clinical studies \\ and at least 1 year follow up \\ to analyze osseointegration \\ of zirconia implants. \\ \end{tabular} & \begin{tabular}{c} The overall survival rate after 12 months ranged \\ between 85\% and 100 with a mean of 95.6\%. \\ follow up was 0.79 mm. \\ \end{tabular} \\  & \begin{tabular}{c} SR with 14 clinical studies \\ and at least 1 year follow up \\ to analyze osseointegration \\ of zirconia implants. \\ \end{tabular} & \begin{tabular}{c} The overall survival rate after 12 months ranged \\ between 85\% and 100 with a mean of 95.6\%. \\ follow up was 0.79 mm. \\ \end{tabular} \\  & \begin{tabular}{c} SR with 54 studies analyzing \\ doseointegration \\ follow up was 0.79 mm. \\ \end{tabular} & \begin{tabular}{c} The mean magnorial bone loss after 12 months \\ are comparable to available \\ data of two-piece \\ titanium implants. \\ \end{tabular} \\  & \begin{tabular}{c} Titanium implants showed a bone to implant \\ (BIC) contact of 60.70\% after the mean \\ follow-up time. In comparison, zirconia \\ implants showed a reduced BIC of \(-\)3.47\%. \\ Titanium implants showed a removal torque \\ analysis of 102.71 Ncm after the mean \\ follow-up time. No significant difference was \\ found for zirconia implants (\(-\)7.31 Ncm, \(p\) = 0.44). In general, smooth implant surfaces \\ (\(-\)43.85 Ncm, \(p\) = 0.03) and implant loading \\ (+40.78 Ncm, \(p\) < 0.01) significantly influenced \\ the removal torque. A roughness of Ra \(>\)2 m \\ and Sa \(>\) 2 m resulted in a positive effect. \\ \end{tabular} \\  & \
\begin{tabular}{c} SR with 19 articles regarding \\ survival rate and marginal \\ bone loss (MBL), with a \\ minimum follow-up of \\ 12 months. \\ \end{tabular} &
\begin{tabular}{c} The marginal bone remodeling of 0.8 mm and \\ 1.01 mm at 1 year and 2 years post-loading, \\ respectively. Overall failure rate of 6.8\% in 2.75 \\ years. Early failure was 3.4\%, late failure was \\ 1.7\%, and implant fracture was 1.7\%. \\ \end{tabular} \\  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \end{tabular}
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Table 1: Summary of systematic reviews (SRs) analyzing the osseointegration of zirconia implants. -anchorage [81; 82]. This soft tissue architecture is considered unsteady and provides an inferior biologic seal [83]. As a consequence, the soft tissues surrounding the implants are more prone to develop inflammatory disease processes. Furthermore, implants with a thin phenotype and inadequate keratinized mucosa width (less than 2 mm) have a higher prevalence of peri-implantitis and peri-implant mucositis [83; 84; 85], demonstrating that soft tissue plays a crucial role in implant health.