Influence of immediate postoperative gingival thickness and gingival margin position on the outcomes of root coverage therapy: A 6 months prospective case series study using 3D digital measuring methods.

BACKGROUND: To assess linear and volumetric changes following the treatment of gingival recessions (GRs) by means of a modified coronally advanced tunnel technique combined with acellular dermal matrix (MTUN + ADM). MATERIALS AND METHODS: Patients presenting GR type 1 (RT1) GRs underwent root coverage surgery consisting of MTUN + ADM. Clinical measurements were made, and intraoral scans were obtained at baseline, postoperatively, and 6 weeks, 3 and 6 months after surgery, to evaluate changes in probing depth (PD), keratinized tissue width (KTW), recession depth (RD), recession area (RA), marginal gingival thickness (MGT), and mucosal volume (MV). The impact of patient-level and surgical-site variables upon percentage root coverage (% RC) and the likelihood of achieving complete root coverage (CRC) were explored. RESULTS: A total of 20 patients (n = 47 teeth) were treated. After 6 months, RD and RA decreased, while KTW, MGT, and MV increased. The mean % RC was 93% at 6 months and CRC was found on 72.3% of the sites at 6 months. The postoperative MGT changes at 1.5 and 3 mm were significantly correlated to % RC and CRC at 6 months. Each additional mm of postoperative gain of gingival thickness resulted in a 4-fold increase in the probability of achieving CRC. Additionally, gingival margin positioned >/=0.5 mm coronal to the cementoenamel junction immediately after surgery was a strong predictor of CRC. CONCLUSIONS: The MGT gain at 1.5 and 3 mm achieved in the immediate postoperative period is a significant predictor of CRC at 6 months when treating multiple GRs via MTUN + ADM. CLINICAL SIGNIFICANCE: The Scientific rationale for the study relies on the lack of 3D digital measuring tools in the assessment of soft tissue healing dynamics after root coverage therapy. The principal findings of this study can be summarized as follows: tooth type, tooth position, and post-operative gingival margin position and gingival thickness and volume changes are predictors of CRC. Therefore, the practical implications are that the more thickness and more coronal advancement achieved immediately after root coverage surgery, the higher chance of achieving CRC.