## 4 Discussion
Based on these results, conventional surgical tools promote a faster healing process compared to laser treatment. Moreover, laser treatment can cause large scars, likely owing to carbonization, although its early hemostatic ability is also related to this process. Additionally, real-time cross-sectional images of the OCT enable the estimation of inflammatory conditions at each stage of healing. Additionally, gingival thickness is also assessed in the periodontal area. At inflammation sites, the immune response increases blood flow with angiogenesis [31; 32], leadingto increased volume, structural changes, and altered texture [33]. Another challenge is recognizing these changes and determining in real time whether they are resolving. In this study, all the groups showed recovery of gingival thickness to normal structure during the early healing period. Initially, volume defects with rough texture indicated abnormalities. In APF cases, significant volume recovery was observed on day 7 in the scalpel-treated groups, while the laser-treated groups showed similar recovery by day 14. In tongue ulcer cases, both groups exhibited significant volume recovery by day 7. However, a reduction in inflamed gingival thickness was discovered in all the groups across both types of cases. Variations in gingival thickness should be considered as an important factor in early healing evaluation [34; 35; 36]. Gingival thickness is crucial not only for healing but also for aesthetic periodontal treatments, such as gingival augmentation and root flap surgery. A three-dimensional assessment of the gingival phenotype is essential in these contexts [37]. To achieve predictable outcomes, differentiating between the epithelial and connective tissue layers and accurately measuring their thickness is necessary. Additionally, bleeding control at the donor site can be improved by identifying the locations of palatal vessels. Observing blood vessels around periodontal tissues is also important. When the inflammatory-immune system activates, one of the most noticeable phenomena is angiogenesis, which can influence the healing process. Blood vessels are typically distinguished from connective tissue by their round or oval shape and lower signal intensity [20]. However, more advanced techniques are available to verify this component, such as OCT with functional angiography (OCT-A) [38; 39]. OCT-A can quantify vessel density and the number of blood vessels, aiding in the assessment of inflammation resolution. Additionally, as previously mentioned, it can be particularly useful in delicate surgeries with bleeding risks by visualizing blood vessels. As mentioned above, the use of OCT is a simple and harmless way to observe the presence of inflammation, soft tissue thickness, and vascularization during the early healing process of periodontal tissue. However, OCT also has limitations that need to be addressed. OCT images became unclear beyond an approximate depth of 1.5 mm [20]. For biological depth measurements, OCT images were approximately 0.41 mm shallower than those obtained from histological calculations [40]. Additionally, the OCT system is less effective at detecting the sulcus anatomy within the function, likely owing to its limited penetration depth. To overcome these obstacles, increasing the center wavelength can enhance penetration depth [41]. However, this approach may decrease the resolution of OCT images, necessitating further developments to balance both the imaging depth and quality.