Comparison of changes in the buccal keratinized mucosa between the minimally-invasive crestal incision and apically-positioned full-thickness flap methods for stage-two implant surgery

Abstract

Stage-two implant surgery, which exposes the implant platform to connect the healing abutment, affects the width of the peri-implant keratinized mucosa thereby affecting the long-term prognosis of the implant. The purpose of this study was to compare the changes in the width of the peri-implant buccal keratinized mucosa between the minimally-invasive crestal incision (MCI) procedure and the apically-positioned full-thickness flap (APFTF) method during stage-two implant surgery. A total of 74 implants were placed in 41 patients. The MCI group included 27 implant cases wherein, healing abutments were connected after stage-two implant surgery using the MCI in 18 patients. The APFTF group comprised 47 implant cases wherein, healing abutments were connected after stage-two implant surgery using the APFTF method in 23 patients. The buccal keratinized mucosa widths (BKMW) of the healing abutment and prosthesis were measured at the mesial, central, and distal aspects after the stage-two surgery and the final restoration. A decrease in the BKMW in both groups after stage-two implant surgery was observed when compared with those after the final restoration; furthermore, the BKMW was significantly lower after stage-two implant surgery in the MCI group (p<0.001). No statistically significant difference in BKMW was noted between the MCI and APFTF groups at any point. These results reveal that the APFTF method was more effective than MCI in terms of preserving the buccal peri-implant keratinized mucosa during stage-two implant surgery.