## 3 Results
### Implant Description and Distribution
#### 3.1.4 Selection of Surgical Approach  
Figure 1 describes the selection of the surgical method depending on the number of implants that were used. The surgeon chose almost equally the two-stage and the one-stage surgical approaches  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Surgical** & **Patients, n** & **Age, y** & **Gender** & & **Implant** & **Current Smokers** \\  & & & & & & & **(\%)** \\ \hline
**Total** & **111** & **Male (\%)** & **Female (\%)** & **No.** & **Diameter (mm)** & **Length (mm)** & \\ \hline One-stage & 52 * & 54 \(\pm\) 14 & 44 & 56 & 140 & 4.3 \(\pm\) 0.5 & 12 \(\pm\) 1.4 & 15 \\ Two-stage & 74 * & 55 \(\pm\) 13 & 42 & 58 & 253 & 4.05 \(\pm\) 0.4 & 12.4 \(\pm\) 1.6 & 23 \\ \(p\) & & NS & NS & NS & NS & NS & NS \\ \hline \hline \end{tabular}  
* 15 individuals were included in both groups (one side single-stage the other side two-stage). The differences were considered significant if \(p<\) 0.05.  
\end{table}
Table 1: Demographic and implant-related data.  
when the number of implants per patient was \(\leq\)3 (54.5% vs. 45.5%, respectively, \(p>0.05\)) and preferred the two-stage surgical approach when the number of implants was \(>\)3 (75.5% vs. 24.5%, respectively, \(p<0.05\)). The choice of surgical approach according to jaw site is depicted in Figure 2.  
The one-stage surgical approach was chosen almost equally to the two-stage for the mandible (51.9% vs. 48.2%, respectively, \(p>0.05\)), but the two-stage surgery was chosen almost four times more frequently in the maxilla than the one-stage (81.8% vs. 18.2%, \(p<0.05\)).  
Table 2 describes the crestal bone loss and the gingival index during the last follow-up. There was no difference in any of these parameters between the two groups either in the short term or the long term. The gingival index results also indicated that oral hygiene was satisfactory for all of the patients in both groups.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Surgical** & \multicolumn{2}{c}{**Mesial Marginal**} & \multirow{2}{*}{\(p\)} & \multirow{2}{*}{**Distal Marginal Bone Loss**} & \multirow{2}{*}{\(p\)} & \multicolumn{2}{c}{**Gingival Index at Last**} \\
**Technique** & & & & & & & & & Follow-Up & \\ \hline \multicolumn{1}{c}{} & **Follow-Up** & \multicolumn{2}{c}{**Follow-Up**} & \multicolumn{2}{c}{**Follow-Up**} & \multicolumn{2}{c}{} & \multirow{2}{*}{**0**} & \multirow{2}{*}{**1**} & \multirow{2}{*}{**2**} & \multirow{2}{*}{**3**} \\  & \(\leq\)**36 Months** & & & & & & & & & \\ \hline One-stage & \(1.1\pm 0.7\) & \(1.2\pm 1.4\) & NS & \(1\pm 0.8\) & \(1.3\pm 1.5\) & NS & 71\% & 28\% & 0 & 0 \\ Two-stage & \(0.9\pm 0.7\) & \(1\pm 1\) & NS & \(0.9\pm 0.7\) & \(1.1\pm 1.1\) & NS & 70\% & 30\% & 0 & 0 \\ \(p\) & NS & NS & NS & NS & NS & NS & NS & & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Comparison of average marginal bone loss and gingival index between the two groups.  
Figure 1: The correlation between the number of implants and the surgical technique.  
Figure 2: The correlation between maxilla/mandible implant location and the surgical technique.  
The changing preference of one- vs. two-stage implant procedures over a period of 18 years were as follows respectively-18-16 years 0 vs. 100%; 15-13 years 0 vs. 100%; 12-10 years 25 vs. 75%; 9-7 years 40 vs. 60%; 6-4 years 35 vs. 65%; 3-1 years 45 vs. 55%. While none of the implants were placed using a one-stage protocol in the early years, a tendency to switch to one-stage surgery, reaching over 50%, was clearly evident between in the late years.