## 3 Results  
Forty-five patients (24 women and 21 men), ranging in age from 37 to 87 years (mean age \(60.52\pm 11.75\) years) were enrolled. Full mouth bleeding score (FMBS) and full mouth plaque score (FMPS) at surgery was \(20.00\pm 7.67\%\) and \(21.76\pm 10.83\%\). A total of three intra-operative complications (one apex fracture, one fracture of the inter-radicular septum, and one removal of the septum because of a perialveolar cystic lesion) and 4 complications (one apex fracture, one fracture of the inter-radicular septum, and two removals of the septum because of perialveolar cystic lesions) were reported for CGF and PRF group, respectively (\(P=0.69\)). No post-operative complications were reported for both of the study groups. The location of extraction sites according to the arch in the CGF and PRF group is shown in Figure 1a,b. Figure 1: Tooth distribution in the two groups (**a**) maxilla; (**b**) mandible. The extracted teeth were premolars, first and second molars. The histograms showed a similarity of extraction site distribution between the two treatment groups. The reason for extraction is specified in Table 1.  
There was no significant between-group difference in the baseline alveolar size (both in the VP/L and in the MD dimension), as shown in Table 1.  
There was a statistically significant difference in vestibular-palatal/lingual (VP/L) diameter reduction at 7 days between CGF and PRF group (\(p\) = 0.04) (Table 2). No significant between-group differences of VP/L diameter change were detected at 14 and 21 days (\(p\) > 0.05). No statistically significant differences of mesio-distal (MD) diameter reduction was reported at 7, 14 and 21 days between CGF and PRF group (Table 2). \begin{table}
\begin{tabular}{c c c c} \hline  & **CGF** & **PRF** & **P-Value** \\ \hline Maxilla/mandible (n. teeth) & 24/21 & 24/21 & \(P\) = 1 \\ Reason for extraction (n.teeth) & 28 & 26 & \\ - advanced caries & 2 & 3 & \\ - Periodontal disease & 15 & 16 & \(P\) = 0.89 \\ - Tooth fracture & 2 & 3 & \\ Baseline alveolar size VP/L, mean \(\pm\) SD (mm) & 9.42 \(\pm\) 2.71 & 9.22 \(\pm\) 1.81 & \(P\) = 0.68 \\ Baseline alveolar size MD, mean \(\pm\) SD (mm) & 9.51 \(\pm\) 4.03 & 9.18 \(\pm\) 2.88 & \(P\) = 0.65 \\ Intra-operative complications (number) & 3 & 4 & \(P\) = 0.69 \\ Post-operative complications (number) & 0 & 0 & N.A. \\ Healing index at day 7 (score) & 5.22 \(\pm\) 1.36 & 5.40 \(\pm\) 1.29 & \(P\) = 0.53 \\ \hline \end{tabular}
\end{table} 
Table 1: Characteristics of the patients and outcomes in the two groups. \begin{table}
\begin{tabular}{c c c c c c c} \hline  & \multicolumn{3}{c}{**Vestibulo-Palatal/Lingual Change, mm**} & \multicolumn{3}{c}{**Mesio-Distal Change, mm (\% Closure**} \\  & \multicolumn{3}{c}{**(\% Closure Respect to Baseline)**} & \multicolumn{3}{c}{**Respect to Baseline)**} \\ \hline
**Group** & **0–7 Days** & **0–14 Days** & **0–21 Days** & **0–7 Days** & **0–14 Days** & **0–21 Days** \\ \hline
**CGF** & \(1.89\pm 1.79\) & \(4.24\pm 1.90\) & \(7.62\pm 2.23\) & \(2.44\pm 1.90\) & \(4.98\pm 2.50\) & \(7.73\pm 3.23\) \\  & \((20.0\%)\) & \((45.0\%)\) & \((80.9\%)\) & \((25.7\%)\) & \((52.3\%)\) & \((81.3\%)\) \\
**L-PRF** & \(1.09\pm 1.82\) & \(3.62\pm 1.95\) & \(7.29\pm 2.02\) & \(1.76\pm 2.39\) & \(4.38\pm 2.60\) & \(7.62\pm 3.04\) \\  & \((11.8\%)\) & \((39.3\%)\) & \((79.0\%)\) & \((19.1\%)\) & \((47.7\%)\) & \((83.1\%)\) \\
**\(P\)-value** & 0.041* & 0.108 & 0.349 & 0.149 & 0.210 & 0.820 \\ \hline \end{tabular}
\end{table} 
Table 2: Changes in alveolar size (closure) up to 21 days in the vestibulo-palatal/lingual and mesio-distal dimension in the two groups. Differences with baseline values are expressed in mm as mean values\(\pm\)standard deviation, and in percentage of closure with respect to baseline. Figure 2a,b show the trend of socket closure in the two treatment groups. The modified healing index averaged \(5.22\pm 1.36\) and \(5.40\pm 1.29\) in the CGF and PRF group, respectively, the values being not significantly different (\(P\) = 0.19).