# The Effect of Different Socket Types on Implant Therapy While Using Flapless Ridge Preservation
## 3 Results
### Independent Factors Influencing Total Treatment Time  
According to univariate analyses (Table 5), total treatment time was not significantly associated with subjects' age, sex, smoking habits, systematic diseases, bone re-grafting, and materials and methods used in dental surgery. The implant sites in the UM region, and the upper anterior and premolar (non-UM) regions had significantly longer treatment time than those in the lower anterior and premolar (non-lower molar [LM]) regions, with estimated differences of 4.72 (\(p\) < 0.001) and 6.06 (\(p\) = 0.001) months. Sites with a bone density of D2-D3 had a significantly shorter treatment time than those with a bone density of D4, with an estimated difference of \(-\)2.77 months (\(p\) = 0.004). Sites with an extraction aetiology of periodontitis had a significantly longer treatment time than those without periodontitis, with an estimated difference of 2.63 months (\(p\) = 0.003). Sites with primary stability of \(>\)35 N/cm had significantly shorter treatment times than those with primary stability of \(<\)20 N/cm, with an estimated difference of \(-\)2.86 months (\(p\) = 0.033). Class III \begin{table}
\begin{tabular}{c c c c c c c} \hline  & & \multicolumn{6}{c}{**Socket Classification**} \\ \cline{3-6}  & & **I** & **II** & **III** & **IV** & **\(p\)-Value** \\  & & **(\(n\) = 6)** & **(\(n\) = 14)** & **(\(n\) = 16)** & **(\(n\) = 3)** & \\ \hline Implant site & LM & 4 (66.7\%) & 10 (71.4\%) & 11 (68.8\%) & 3 (100.0\%) & 0.861 \\  & Non-LM & 2 (33.3\%) & 4 (28.6\%) & 5 (31.3\%) & 0 & \\ Extraction aetiology & Periodontitis & 0 & 4 (28.6\%) & 9 (56.3\%) & 3 (100.0\%) & 0.010 \({}^{*}\) \\  & Non-periodontitis & 6 (100.0\%) & 10 (71.4\%) & 7 (43.8\%) & 0 & \\  & A & 6 (100.0\%) & 13 (92.9\%) & 14 (87.5\%) & 0 & 0.001 \({}^{*}\) \\  & B1 & 0 & 0 & 2 (12.5\%) & 3 (100.0\%) & \\  & B2 & 0 & 1 (7.1\%) & 0 & 0 & \\  & D1 & 0 & 0 & 1 (6.3\%) & 1 (33.3\%) & 0.453 \\ Bone density & D2-D3 & 2 (33.3\%) & 6 (42.9\%) & 9 (56.3\%) & 1 (33.3\%) & \\  & D4 & 4 (66.7\%) & 8 (57.1\%) & 6 (37.5\%) & 1 (33.3\%) & \\ Bone re-grafting & Yes & 2 (33.3\%) & 13 (92.9\%) \({}^{\dagger}\) & 12 (75.0\%) & 2 (66.7\%) & 0.041 \({}^{*}\) \\  & No & 4 (66.7\%) & 1 (7.1\%) & 4 (25.0\%) & 1 (33.3\%) & \\  & \(<\)20 N & 0 & 0 & 1 (6.3\%) & 0 & 0.475 \\ Primary stability & 20-35 N & 2 (33.3\%) & 1 (7.1\%) & 4 (25.0\%) & 0 & \\  & \(>\)35 N & 4 (66.7\%) & 13 (92.9\%) & 11 (68.8\%) & 3 (100.0\%) & \\  & Success & 6 (100.0\%) & 12 (58.7\%) & 15 (93.8\%) & 3 (100.0\%) & 0.649 \\ Implant survival & Late failure & 0 & 2 (14.3\%) & 0 & 0 & \\  & Early failure & 0 & 0 & 1 (6.3\%) & 0 & \\  & Period from extraction to stage I surgery & 3.7 (1.8, 4.0) & 3.5 (2.8, 3.8) & 4.0 (3.0, 4.8) & 5.2 (4.7, 13.0) & 0.052 \\  & (months) & 8.6 & 8.4 & 8.9 & 9.8 & 0.716 \\ Period from stage I surgery to final prosthesis & (7.4, 11.6) & (7.0, 9.5) & (6.5, 9.8) & (7.8, 10.7) & \\ Total treatment time between extraction and & 13.1 & 12.2 & 13.1 & 15.9 & \\  & final prosthesis placement (months) & (12.0, 13.4) & (10.6, 12.8) & (11.1, 14.1) & (14.5, 20.8) & 0.086 \\ \hline \end{tabular}  
* Indicates \(p\) < 0.05; a significant difference is observed among the four socket classes I-IV. \({}^{\dagger}\) The proportion of bone re-grafting in Class II is significantly higher than that of Class I. DM, diabetes mellitus; LM, lower molar.  
\end{table} 
Table 4: Association of socket classification and implant site development for mandibular implants with flapless ridge preservation. sockets had a longer treatment time than Class I sockets, with an estimated difference of 3.09 months (\(p\) = 0.024). To determine whether the above five factors (implant site, bone density, primary stability, extraction aetiology, and socket classification) had an independent influence on the total treatment time, they were included in a model by stepwise selection.