## 3 Results
### Secondary Outcome of the Intervention on Clinical Attachment Gain (CAL)  
In total, 4 of the 12 included studies did not assess the CAL gain, and 2 studies that did assess this parameter did not present numerical data, leaving 6 studies for a quantitative comparison of this parameter. The frequency of follow-up assessments varied from one to four follow-up appointments. Studies with the same follow-up period of 10 days, 4 weeks, or 12 weeks are compared in Table 5.  
Two studies evaluated the patients 10 days after the initiation of NSAID treatment. [PERSON] et al. (2018) reported a gain in CAL by 0.5 mm (SD 1.98 mm) in the non-NSAID group compared to 1.2 mm (SD 2.13 mm) in the NSAID group after 10 days and greater after 30 days. [PERSON] et al. (2018) observed a gain of 0.29 mm (SD 0.51) in the CAL in the smoking non-NSAID group, while the non-smoker control group showed a clinical attachment gain of 0.01 mm (SD 1.16). In contrast, the non-smokers of the NSAID group showed no difference in CAL gain compared to the smokers in this group with 0.01 mm (SD 1.5). At four weeks of follow-up, the observed CAL was comparable between the non-NSAID group and the NSAID group in the two studies with a re-evaluation at this timepoint. [PERSON] et al. (2018) reported a CAL gain of 2.23 mm (SD 1.36 mm) in the control group compared to 1.95 mm (SD 0.71) in the NSAID group, while [PERSON] et al. (2018) observed only minimal changes in this parameter four weeks after initiation of the treatment, with a gain in CAL of 0.009 mm (SD 1.02 mm) and on average \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Study and Groups** & **Non-NSAID (\(\mathbf{u}\))** & **NSAID (\(\mathbf{u}\))** & **ABOP in mm** & **ABOP in mm** & **Dose (\%)** \\  & & & **Non-NSAID (SD)** & **NSAID (SD)** & **NSAID (SD)** & \\ \hline \multicolumn{6}{c}{10 day-follow-up} \\ \hline [PERSON] et al., 2010 & 20 & 20 & \(-1.60\) (0.99) & \(-1.50\) (1.13) & 50 \\ [PERSON] et al. 2007 & & & & & 33.3 \\ smokers & 15 & 14 & \(-1.50\) (0.41) & \(-1.32\) (0.40) & \\ non-smokers & 15 & 14 & \(-1.60\) (0.16) & \(-1.28\) (0.69) & \\ \hline \multicolumn{6}{c}{4 week/30 days-follow-up} \\ \hline [PERSON] et al., 2010 & 20 & 20 & \(-1.8\) (0.76) & \(-2.1\) (0.89) & 50 \\ [PERSON] et al., 2008 & 10 & 10 & \(-47.58\)\% (22.01) & \(\begin{matrix}-57.44\%\\ (15.43)\end{matrix}\) & 100 \\ [PERSON] et al., 2014 & 16 & 16 & \(-0.53\) (0.37) & \(-0.59\) (0.29) & 50 \\ \hline \multicolumn{6}{c}{12 week-follow-up} \\ \hline [PERSON] et al., 2003 & 10 & & \(-1.85\) (1.28) & \\ Nimesulide & & 10 & \(-2.10\) (1.00) & 50 \\ Naproxen & & 10 & \(-1.85\) (1.13) & 137.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Bleeding on probing (BOP) in comparison to non-NSAID and NSAID groups at three different follow-up timepoints. no change in the NSAID group (SD 1.27). Two studies evaluated the CAL after a follow-up period of 12 weeks. [PERSON] et al. [31] reported a gain in CAL for all three groups (placebo/non-NSAID group, Nimesulide, or Naproxen) of 1.3, 1.35, and 1.15 mm, respectively. [PERSON] et al. [33] found the highest gain in CAL in the NSAID group with deep PD at 3.04 mm (SD 11.83 mm). The control group with deep PD showed an average gain of 1.46 mm (SD 12.82). The gain of the CAL in patients with moderate pockets was comparable between the NSAID-group (\(-\)1.06 mm, SD 7.42 mm) and the non-NSAID control group (\(-\)0.83 mm, SD 7.42 mm). Numerical data from six studies could be quantitatively evaluated for the CAL between the NSAID and control groups. The data are plotted in Figure 3 to demonstrate the observed gain in CAL in these six studies. Three of the six evaluated studies showed close to no difference in the average clinical attachment gain between the non-NSAID and NSAIFD groups.