# Variables Affecting Peri-Implant Radiographic Bone Loss-8-23 Years Follow-Up
## 4 Results
### Intervariable Interactions  
Intervariable interactions were calculated prior to multivariate analysis. Bone loss was significantly lower among external hex implants, installed without GBR (\(p\) = 0.008, OR = 8, CI 1.71-37.42). Interestingly, no significant association between the connection type groups was found when implant installation was combined with GBR (\(p\) = 0.811). The significant difference between connection types existed only in the lower jaw (\(p\) = 0.048, OR = 3.49, CI 1.01-12.07). The number of teeth and the number of implants at T0 were significantly correlated with bone loss. When less than 20 teeth and 2 or more implants were present at T0, the odds-ratio for implant bone loss was 3.6 (CI 1.03-12.56), (\(p\) = 0.045). Implants having a length of 10-12 mm as well as a diameter of 3.7-4 mm were significantly more successful (\(p\) = 0.033, OR = 2.71, CI 1.08-6.79). (Table 4)  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Characteristics** & **\% (\%) *** Excess Bone Loss** & \(p\) **Value** & **\% OR** & *** CI \\ \hline With GBR & & & & \\ ext. hex & 29\% (9) & & & \\ int. hex & 26.1\% (6) & 0.811 & & \\ \hline Without GBR & & & & \\ ext. hex & 5.4\% (2) & & & \\ int. hex & 31.4\% (16) & 0.008 & 8 & 1.71–37.42 \\ \hline T\({}_{0}\)\(n\) Teeth and \(n\) Implants & & & & \\ \(\geq\)20 and \(<\)2 & 11.8\% (4) & & & \\ \(<\)20 or \(\geq\)2 & 23.9\% (17) & 0.153 & & \\ \(<\)20 and \(\geq\) 2 & 32.4\% (12) & 0.045 & 3.6 & 1.03–12.56 \\ \hline Upper jaw & & & & \\ ext. hex & 20\% (6) & & & \\ int. hex & 27.1\% (13) & 0.48 & & \\ \hline Lower jaw & & & & \\ ext. hex & 13.2\% (5) & & & \\ int. hex & 34.6\% (9) & 0.048 & 3.49 & 1.01–12.07 \\ \hline Implant dimensions & & & & \\ Length Diameter & & & & \\ \(\leq\)12 and \(\leq\)4 & 13.2\% (7) & & & \\ \(>\)13 or \(\geq\)4 & 29.2\% (26) & 0.033 & 2.71 & 1.08–6.79 \\ \hline \hline \end{tabular} * excess bone loss—implants in which radiographic bone loss exceeded 1.5 mm in the first year and 0.1 mm every additional year during the follow-up. ** OR—Odds Ratio. *** CI—Confidence Interval.  
\end{table}
Table 4: Intervariable interactions.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Characteristics** & **\% (\%)** \\ \hline Deepest PD at implant (\(\leq\)3/4–6/\(\geq\)7 mm) & 49.3\% (70)/42.3\% (60)/8.4\% (2) \\ \hline BOP at implant (no/yes) & 16.7\% (22)/83.3\% (110) \\ \hline PII at implant (no/yes) & 12\% (7)/88\% (125) \\ \hline Timing of implantation (immediate/early/late) & 95.8\% (136)/2.8\% (4)/1.4\% (2) \\ \hline Implant dimensions: & \\ Diameter (3.7–4 mm/4.1-5 mm) & 62\% (88)/38\% (54) \\ Length (10–12 mm/13–16 mm) & 69.7\% (99)/30.3\% (43) \\ \hline GBR (no/yes) & 62\% (88)/38\% (54) \\ \hline Sinus augmentation (no/transcrestal/lateral window) & 69\% (98)/8.5\% (12)/22.5\% (32) \\ \hline Restoration type (fixed single/multiple) & 24\% (34)/76\% (108) \\ \hline Restoration quality—proper/overhanging & 78.9\% (112)/4.2\% (6)/16.9\% (24) \\ margin/ill-fitting margin (gap) & 38\% (54)/16.2\% (23)/40.8\% (58)/5\% (7) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Implants related data.