Digital Evaluation of Volumetric Changes of Free Gingival Graft and Gingival Unit Graft With Indirect Method

Deficiency of keratinized tissue includes mucogingival problems among different clinical entities. (Silva et al., 2010) There is no consensus on the minimum amount of attached gingiva required to maintain the health of the gums. However, there are many clinical situations that demonstrate the necessity of keratinized tissue. (Cevallos et al., 2020) (Agarwal et al., 2015) For example, if the attached gingiva is thin, it becomes difficult to perform adequate oral hygiene procedures and plaque. Inflammation and attachment loss are observed due to accumulation. (Gümüş and Buduneli, 2014) (Raoofi et al., 2019) Keratinized tissue width expresses the distance between the coronal margin of the gingival sulcus and the mucogingival line. It is considered to be the main factor in the management and protection of tissue health around natural teeth. (Agudio et al., 2019) Gingival recession refers to the apical displacement of the soft tissue margin from the cemento-enamel border. Oral hygiene and plaque with tooth sensitivity, root caries, unaesthetic appearance as well as loss of periodontal attachment causes retention. (Arzouman et al., n.d.) (Chambrone and Tatakis, 2015) In the treatment of gingival recession Many techniques have been described: Subepithelial connective tissue graft, stemmed grafts (coronally, laterally), free gingival graft (FGG), gingival unit graft (GUG). (Cevallos et al., 2020)(Sriwil et al., 2020). Although significant results are observed, there are different success rates between techniques. (Sriwil et al., 2020) FGG is used not only to cover the root surface but also to increase the width of keratinized tissue. It was first proposed by Nabers for this purpose. (Mörmann et al., 1981) Currently, the FGG's incompatible aesthetic and crude. It has many limitations due to its appearance. (Sriwil et al., 2020)

Due to the limitations of the FGG, there was a need for a new perspective on such phenomena. The vascular characteristics of the graft are important in terms of rapid capillary anastomosis with impaired vascularity of the recipient site. (Sriwil et al., 2020) Gingival sulcus, where thin blood vessels form a network and capillaries show numerous anastomoses is the place. (Jenabian et al., 2016) The vascular plexus of the gingiva, in terms of horizontal anastomoses feeding the marginal zone marginal and interdental tissues to benefit from better blood perfusion of the recipient area can be used, thus increasing the chances of survival of the graft. (Sriwil et al., 2020) (Yıldırım, 2015) The supracrestal part of the gingiva, which includes the marginal and papillary tissues, is included in the soft tissue graft taken to nourish the avascular root surface.

Studies have shown that the marginal, attached, and interdental gingival regions have significantly different vascular distributions. (Sriwil et al., 2020)

Due to these advantages of marginal and interdental tissues, the technique defined as Gingival Unit Graft (GUG) containing marginal and interdental papilla has emerged as an alternative approach to FGG. (Yıldırım, 2015) Kuru and Yıldırım, in their randomized controlled study comparing FGG and GUG in terms of keratinized tissue gain and root surface coverage, reported that DÜG gave better clinical results. (Dry oath Yıldırım, 2013)

G Power 3.1 (University Kiel, Germany) program was used to calculate the effect size. Effect size Free Gingival Graft in the study of Sriwil, Fakher (1) and an effect size of 2.12 d cohen was determined to be sufficient for significance. It was found that a total of 20 samples, at least 10 for each study group, was sufficient with a type 1 error of 0.05 and 99% power.