## 4 Discussion  
The main surgical methods used in the treatment of gingival recession are mucogingival procedures with flap preparation, tunnel techniques together with autogenous connective tissue grafts, free gingival grafts and partially de-epithelialized free gingivalgrafts [28; 29; 30; 31]. However, other alternatives have also been employed, including substitutes for autogenous connective tissue (allogeneic, xenogeneic, synthetic meshes), tissue cultures (fibroblasts, keratinocytes), guided tissue regeneration (resorbable and nonresorbable barrier membranes) as well as biologically active proteins (amelogenins, growth factors) [4; 25; 32]. The golden standard involves the usage of a connective tissue graft harvested from the mucous membrane of the hard palate combined with flap displacement or the creation of supraperiosteal tunnels. These methods show the best long-term clinical and aesthetic results [33; 34; 35; 31]. According to [PERSON] et al. [36] the outcome measures of this 24-month follow-up study can be classified as medium term (13-59 months). Most of the studies evaluating the clinical and aesthetic outcome of gingival recession coverage are of short term, i.e., 6-12 months [37; 38; 39; 40], and only a few are of long term (\(\geq\)60 months) [35; 41; 42; 43; 44]. No similar study assessing the use of augmented connective tissue in the coverage of MAGRs was found in the available literature. Only one study was focused on a two-year evaluation of multiple gingival recession coverage, but here the modified CAF/EMD method and CAF alone was performed [45]. [PERSON] et al. [45] compared clinical outcomes after 6 and 24 months in 10 patients with at least two bilateral adjacent gingival recessions (58 recessions in total, 29 in each group) after the treatment with a CAF/EMD (Test) enamel matrix derivative and modified CAF alone (Control). Mean root coverage after six months in the test group was 82.8% and in the control group 80.7%, and after 24 months 74.8% and 71.0% respectively. After six months the authors obtained complete root coverage in 13 out of 29 sites (45%) in the control group and in 9 out of 29 sites (31%) in the test group but after 24 months CRC was equal 24% and 17%, respectively. Similarly, there were no statistically significant differences between the groups in terms of KTWs and CAL, but differences between the mean baseline values as well as between 6 and 24 months CRC were found. Two years after intervention CAL gain was 50% in the CAF alone group and 54.3% in the CAF/EMD group. Average PD values during the whole observation period did not change in comparison to baseline, which is consistent with our results. In our study, after six months the ARC was 93.22% in the test group and 91.47% in the control group, and after 24 months, 91.76% and 89.90% respectively. The CRC after six months was 71.43% in the test group and 66.20% in the control group, and after two years 67.53% and 57.75% respectively. Furthermore, better results compared to [PERSON] et al. [45] were recorded in the CAL gain values (%CAL), with an average value of 73.56% in the augmented CTG group and 71.98% in the nonaugmented CTG group. Our collated results demonstrate postoperative stability during the two-year observation period, and the percental increase in CAL gain throughout time can possibly be related to the phenomenon of creeping attachment, especially among the augmented CTG group. In another study, [PERSON] et al. [42] compared the results of the coverage of 93 Miller class I, II, III maxillary MAGRs in 13 patients, treated using the CAF/CTG method and CAF alone during a 5-year observation period. In both study groups, recessions were located in the area of incisors, canines and premolars. However, four recessions were located in the area of first molars, while 15 gingival recessions were of Miller class III (8 in the CAF/CTG group), which is comparable to our study (11 Miller class III gingival recessions in the test and 17 in the control group).