## 3 Results
### Meta-Analysis  
Fourteen studies were analyzed quantitatively because they shared similar characteristics such as HA concentration and 12-week follow-up. A meta-analysis was conducted on two subgroups, which were divided into those that used a HA concentration \(>\) 0.8% (not including the 1.6%) and those that used a HA concentration \(<\) 0.3%. This was performed to compare the effect of HA on reducing probing pocket depth (\(\Delta\)PPD), clinical attachment level (\(\Delta\)CAL), and bleeding on probing (\(\Delta\)BOP) from baseline to 12 week follow-up. The means and standard deviations of the change in PPD, CAL, and BOP from baseline are presented in Figure 3, Figure 4, and Figure 5, respectively.  
Baseline scores generally showed no significant differences. The overall analysis yielded the following: [WMD \(-\)0.68; 95% CI (\(-\)1.14, \(-\)0.21) with heterogeneity I\({}^{2}\) 95%, and \(p\) < 0.00001]. The first subgroup analysis (SRP plus HA > 0.8%) showed the following: [WMD \(-\)0.73; 95% CI (\(-\)1.35, \(-\)0.10 with heterogeneity I\({}^{2}\) 95%, and \(p\) < 0.0001]. The second subgroup analysis (SRP plus HA < 0.3%) showed the following: [WMD \(-\)0.59; 95% CI (\(-\)1.68, 0.50) with heterogeneity I\({}^{2}\) 95%, and \(p\) < 0.0001]. The PPD analysis indicates that the addition of HA 0.8% yields slightly better results, although HA < 0.3% also produces a positive outcome compared to traditional therapy, with a minimal difference between the two concentrations (Figure 3).  
For CAL analysis, the baseline scores generally showed no significant differences. Overall analysis yielded [WMD--124; 95% CI (\(-\)1.37, \(-\)1.11) with heterogeneity I\({}^{2}\) 94%, and \(p\) < 0.00001]. The first subgroup analysis (SRP plus HA > 0.8%) showed [WMD \(-\)132; 95% CI (\(-\)1.46, \(-\)1.18) with heterogeneity I\({}^{2}\) 95%, and \(p\) < 0.0001]. The second subgroup analysis (SRP plus HA < 0.3%) showed [WMD \(-\)132; 95% CI (\(-\)1.46, \(-\)1.18) with heterogeneity I\({}^{2}\) 95%, and \(p\) < 0.0001]. The second subgroup analysis (SRP plus HA < 0.3%) showed [WMD \(-\)0.69; 95% CI (\(-\)1.04, \(-\)0.33) with heterogeneity I\({}^{2}\) 87%, and \(p\) = 0.004]  
Figure 4: Forest plot of the meta-analysis of CAL [18; 19; 22; 24; 28; 33; 35; 36].  
Figure 5: Forest plot of the meta-analysis of BOP [19; 22; 24; 28; 33; 35; 36].  
BoP analysis on SRP with HA 0,8% versus SRP showed statistically significant differences with \(p<0.00001\). Overall analysis showed the following: [WMD \(-041\); 95% CI (\(-0.44\)-\(0.37\)) with heterogeneity I\({}^{2}\) 99%, and \(p<0.00001\)] (Figure 5).  
The meta-analysis revealed substantial or considerable heterogeneity among the included studies (I\({}^{2}\) ranging from 87% to 95%), which considerably limits the reliability and generalizability of the aggregate estimates. Potential sources of heterogeneity may include differences in study design, population characteristics, sample size under investigation, HA concentrations or formulations, outcome measures, and duration of follow-up. Although a random-effects model was applied to account for this variability, the results should be interpreted with caution.