## 3 Results  
### Basic Characteristics of Patients and Implants  
The present cohort consisted of 131 women (48.2%) and 141 mean (51.8%) with a mean age of \(65.2\pm 13.9\) years (Table 1). Straumann and Thommen implants were used in 206 (75.7%) and 66 (24.3%) patients, respectively. Distribution of men (101/206, 49.0%) and women (105/206, 51.0%) was similar for Straumann implants. In contrast, Thommen implants were predominantly inserted in men (40/66, 60.6%) vs. women (26/66, 39.4%).  
Figure 1: Illustration of the resonance frequency analysis (RFA): (**A**) insertion of the measurement adapter, (**b**) resonance frequencies measured with the device, (**C**) implant with adapter in situ, (**D**) RFA-measurement from the vestibular side, and (**E**) implant stability meter with implant stability quotient (ISQ) values for the evaluation.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{1}{c}{**Total Patients**} & **STR \({}^{\ddagger}\)** & **SPI \(\ddagger\)** \\
**Variable** & **(\(n\) = 272; 100\%)** & **(\(n\) = 206; 75.74\%)** & **(\(n\) = 66; 24.26\%)** \\  & \(n\) (\%)** & \(n\) (\%)** & \(n\) (\%) \\ \hline
**Age** & & & \\ Mean \(\pm\) standard deviation & 65.15 \(\pm\) 13.9 & 64.21 \(\pm\) 13.8 & 67.86 \(\pm\) 13.8 \\ \(<\)65 & 133 (48.90) & 110 (53.40) & 23 (34.85) \\ \(\geq\)65 & 139 (51.10) & 96 (46.60) & 43 (65.15) \\ _Sex_ & & & \\ w & 131 (48.16) & 105 (50.97) & 26 (39.39) \\ m & 141 (51.84) & 101 (49.03) & 40 (60.61) \\  & **Total implants** & **STR \({}^{\ddagger}\)** & **SPI \(\ddagger\)** \\
**Variable** & **(\(n\) = 582; 100\%)** & **(\(n\) = 432; 74.23\%)** & **(\(n\) = 150; 25.77\%)** \\  & **\(n\)(\%)** & **\(n\)(\%)** & **\(n\)(\%)** \\
**Region** & & & \\  & Mandibular & 239 & 187 & 52 \\ \(\Rightarrow\) Front teeth: tooth 31–33; 41–43 & 40 (16.74) & 34 (18.18) & 6 (11.54) \\ \(\Rightarrow\) Premolar tooth 34–35; 44–45 & 72 (30.13) & 52 (27.81) & 20 (38.46) \\ \(\Rightarrow\) Molar: tooth 36–38; 46–48 & 127 (53.14) & 101 (54.01) & 26 (50.00) \\  & Maximly & 343 & 245 & 98 \\ \(\Rightarrow\) Front teeth: tooth 11–13; 21–23 & 110 (32.07) & 76 (31.02) & 34 (34.69) \\ \(\Rightarrow\) Premolar: tooth 14–15; 24–25 & 138 (40.23) & 105 (42.86) & 33 (33.67) \\ \(\Rightarrow\) Molar: tooth 16–18; 26–28 & 95 (27.70) & 64 (26.12) & 31 (31.63) \\  & **Implant diameter** & & \\ Mean \(\pm\) standard deviation & 4.22 \(\pm\) 0.5 & 4.11 \(\pm\) 0.5 & 4.53 \(\pm\) 0.5 \\  & Median (range) & 4.1 (3.3–6) & 4.1 (3.3–5.8) & 4.5 (3.5–6) \\  & 3.3 mm & 70 & 70 & - \\  & 3.5 mm & 2 & - & 2 \\  & 3.6 mm & 1 & 1 & - \\  & 4 mm & 1  
A total of 628 implants, 432 (74.2%) Straumann and 150 (25.8%) Thommen, were examined. Median diameter and length for Straumann implants were 4.1 mm (range: 3.3-5.8 mm) and 10 mm (range: 4-14 mm), respectively. The respective values for Thommen implants were 4.5 mm (range 3.5-6 mm) and 11 mm (range: 4.2-14.5 mm). Implants were predominantly inserted in the maxillary premolar region (138/628, 40.2%), followed by the mandibular molar region (127/628, 53.1%) and the maxillary front tooth region (110/628, 32.1%). For Straumann implants, most implants were set in the maxillary premolar (105/432, 24.3%) and mandibular molar tooth region (101/432, 23.4%); for Thommen implants, the maxillary front tooth region (34/150, 22.7%) and maxillary premolar region (33/150, 22.0%) were the most frequent sites. From all included implants, 482/628 (82.8%) were inserted into fully ossified bone, 54/628 (9.3%) were inserted immediately after tooth extraction, 24/628 (4.1%) were inserted in either one or two steps after sinus elevation, 13/628 (2.2%) were inserted after bone augmentation, and 9/628 (1.6%) were inserted immediately after sinus elevation. These bone situations and surgical insertion techniques were equally distributed in STR and SPI groups. However, immediate insertions of implants were more frequently seen in the SPI implant group compared to STR (Figure 2).