Comparison of methods used in determining gingival phenotype and the effect of clinical variables on periodontal phenotype

Background and Aim: Periodontal phenotype affects the planning and clinical results of treatments and plays an important role in maintaining periodontal health, function and aesthetics. The aim of this study is (1) to classify the gingival phenotype with different methods and compare these methods, (2) to examine the relationship between periodontal phenotypic parameters measured from different reference points. Materials and Methods: Gingival-Thickness (GT) in the upper anterior 6 teeth of 30 healthy individuals without a history of periodontitis was evaluated by Transgingival-Probing (TP), Standard-Periodotal-Probing (SPP), Colored-Periodontal-Probing (CPP) and Cone-Beam-Computed-Tomography (CBCT) methods. The gingival phenotype was classified as thin or thick. The relationship of thin and thick gingival phenotype with phenotypic variables and clinical parameters such as age, gender, Gingival-Recession (GR), Keratinized-Tissue-Width (KTW) and Buccal-Bone-Thickness (BBT) was compared. Reference points (margin-mid-apical) were determined from the mid-buccal of each tooth. GT, BBT and related phenotypic parameters measured from these points using TP and CBCT methods were compared. Results: All methods were found to be significantly correlated and compatible with each other in terms of detecting thin or thick gingival phenotype (p<0.05). Gingival phenotype was not significantly associated with age, gender, or GR (p>0.05), but more KTW was found in regions with thick gingival phenotype (p:0.008). GT at the margin was measured to be significantly higher than at the middle and apical (p<0.01). BBT was measured more in the middle region than in the apical region (p<0.01). GT values at 3 points measured by TS and CBCT were significantly correlated (p<0.01). A positive correlation was found between KTW and GT, BBT and GT at the margin (p<0.01). Conclusion: Thin or thick phenotype is associated with different apico-coranal reference points and KTW. TP and CBCT methods are useful for this purpose. There is a need to develop well-planned treatment protocols, taking into account different reference points in tissue and bone regions.