Efficacy of free gingival grafting to augment keratinized mucosa around dental implants in posterior regions after restorative procedures: A retrospective clinical study

Statement of problem. Data on the shrinkage of free gingival grafts (FGGs) vary. Most studies have analyzed grafts in nonmolar sites because of measurement limitations and have addressed the changes in grafts and keratinized mucosa width (KMW) only in the early healing phase.Purpose. The purpose of this retrospective clinical study was to assess the dimensional changes of an FGG in the posterior regions and their influencing factors, with the aim of obtaining sufficient and stable KMW after restoration.Material and methods. A total of 77 implants in 40 participants who had undergone an FGG surgery were recruited. Graft sizes during surgery and the surface areas of keratinized mucosa at the follow-up visit after restorations were compared by digital analysis and verified by clinical measurements and photographs. The association between shrinkage and the graft sizes, implant location, and sex and age of the participants was evaluated. The influence of the shrinkage of FGG on the KMW after restoration was analyzed by multivariable linear regression with generalized estimating equation (GEE) models.Results. The mean +/- standard deviation shrinkage of FGG around implants in the posterior regions was 24.76 +/- 14.77%, and the mean +/- standard deviation KMW was 4.16 +/- 1.77 mm at the follow-up visit. Larger grafts had a statistically higher shrinkage ratio (P<.001). No statistically significant difference was found regarding the effect of implant location, sex, and age on the shrinkage of FGG and final KMW (P>.05). The mean +/- standard deviation follow-up period after restoration was 12.45 +/- 7.73 monthsConclusions. Free gingival grafting was found to be a predictable treatment approach for augmentation of KMW around implants in the posterior region after the fabrication of prostheses as long as grafts of sufficient size were placed. Stable outcomes were shown in the study participants in the follow-up period of up to 3 years (J Prosthet Dent 2023;130:715-22)