Effectiveness of keratinized mucosa augmentation procedures around dental implants based on risk assessment: a 5-year retrospective cohort study

Abstract

Abstract Objectives: Evidence on the decision-making of keratinized mucosa (KM) augmentation procedures around dental implants is lacking. The aim of this study was to evaluate the effectiveness of KM augmentation with different techniques around dental implants based on risk assessment. Materials and methods: Thirty-nine patients who underwent KM augmentation at implant sites in the posterior mandible were included. Three different techniques were used based on risk assessment: apically positioned flap (APF alone), apically positioned flap plus free gingival graft (APF plus FGG), and apically positioned flap plus collagen matrix (APF plus CM). Keratinized mucosa width (KMW), implant/prosthesis survival rates, and bone/soft tissue parameters were analyzed. The correlation between local anatomy characteristics and different techniques was tested separately. The association between KM augmentation outcomes and related factors was analyzed using linear model. Results: In overall, 74 sites received KM augmentation in the lower jaw, with an effective rate of 94.6% in 1-year follow-up and 93.2% in 5-year follow-up.KMW for APF plus FGG group (3.85±1.22 mm) appeared to be higher than those for APF alone group (3.05±0.90 mm) and APF plus CM group (3.21±1.17 mm) after 5 years. There was no significant difference on the effective/ineffective outcomes in 1-year and 5-year follow-up among the three groups. Conclusions: Comparable effective outcomes would be achieved with three different KM augmentation techniques following the decision-making criterion based on risk assessment. Study registration: Chinese Clinical Trial Registry (ChiCTR2200062113) Clinical Relevance Scientific rationale for study: The clinical effectiveness of KM augmentation procedures around implants has been documented. However, limited studies reported detailed anatomical characteristics and evidence on the decision-making of KM augmentation procedures around dental implants is lacking. Principal findings: APF plus FGG could achieve more KW than APF alone and APF plus CM, though there was no significant difference on the effective/ineffective outcomes in 5-year follow-up. Practical implications:Risk assessment according to anatomical characteristics is necessary before the KM augmentation surgery. Comparable effective outcomes can be achieved with different KM augmentation techniques following the decision-making criterion based on risk assessment.