The gain in keratinized gingiva using apically positioned flap during implant placement with and without ridge augmentation: A comparative prospective study.

OBJECTIVES To evaluate whether ridge augmentation (RA) affects the gain in keratinized gingiva (KG) in implant surgery using a full-thickness apically positioned flap (fAPF). MATERIAL AND METHODS We conducted a prospective study from April 2017 to April 2019 recording patient- and implant-related factors. The subjects underwent fAPF during implant placement and were divided two groups: Group A, one-stage surgical protocol without RA; Group B, two-stage surgical protocol with RA. The initial width of KG and the width of KG at 1 week, 3 weeks, 3 months, and 6 months after surgery and baseline were measured using a paper ruler. Multivariable generalized estimating equation (GEE) models were estimated to evaluate RA effects on the gain in KG, the shrinkage amount of KG, and shrinkage ratio of KG after fAPF. RESULTS Seventy-nine participants with 203 implants were included. The baseline values of KG were 1.68 mm in Group A and 0.82 mm in Group B (p   0.05). The gain in KG was 1.92 ± 1.67 mm in Group A, 1.48 ± 1.36 mm in Group B. The total shrinkage amount and the shrinkage ratio of KG were 1.87 mm and 42.43%, respectively. CONCLUSIONS A fAPF is a reliable technique that enables significant increase in KG regardless of RA in implant surgery.