The Effect of Connective Tissue Graft Compared to Concentrated Growth Factor Graft on Buccal Peri-Implant Gingival Thickness: A 12-month Randomized Controlled Clinical Trial

Attached gingival phenotype has a crucial impact on the implant's durability and its future success. This study aims to measure and compare buccal peri-implant gingival thickness following grafting with connective tissue graft (CTG) and the concentrated growth factor (CGF) graft. This is a split-mouth designed randomized controlled clinical study in which a total of 20 aged 18 to 55 have bilateral missing teeth in the maxillary premolar region with less than 2 mm of healthy peri-implant gingival thickness. Patients were excluded if they were smokers, had poor oral hygiene, had uncontrolled widespread periodontal disease, or had a history of radiation treatment. The same surgical protocol was followed for each study participant, where an independent blinded medical practitioner assigned the first stage side to be treated with CTG, while the second stage side with CGF 2 weeks later. The primary exposure variable of this study was the gingival grafting technique; CTG or CGF. The primary outcome variable was the buccal peri-implant gingival thickness. Gingival thickness was measured at six different times; immediately before the procedure (T0), after 30 days (T1), after 45 days (T2), after 3 months (T3), after 6 months (T4), and after 12 months (T5). The covariates were age, sex general health, and periodontal status. The statistical analysis; repeated measures analysis of variance test was used to compare the gingival thickness between the studied follow-up times within each group. The level of significance was set at ≤ 0.05. The sample was composed of 40 treatment sites of 20 patients. The mean age of the sample was 32 years and 45% were male. The mean gingival thickness value of the CTG group was 1.62 mm with a (standard deviation = 0.18) compared to 1.28 mm for the CGF group with (standard deviation = 0.20) and an overall P value (0.001) at T5. CTG showed to have better gingival thickness than CGF in managing peri-implant buccal gingival thickness deficiency.