The width of keratinized mucosa around dental implants and its influencing factors.

BACKGROUND: A few evidence is available in the literature concerning the pattern of variation in the width of keratinized mucosa (KMW) around dental implants and factors that may affect the KMW. PURPOSE: The purpose of this study is to investigate the KMW at the buccal aspect of dental implants and to analyze its influencing factors. MATERIALS AND METHODS: The current study was a retrospective study conducted on 726 patients with 1252 dental implants. The following parameters were evaluated by reviewing the medical records of each patient, including the age, gender and smoking status of each patient, the reasons of teeth loss, the position of implants, the bone augmentation procedures, and the KMW. Binary logistic regression analysis with the generalized estimating equations was utilized to analyze the factors that may affect the KMW of dental implants. RESULTS: The KMW of implants located in the maxilla was significantly higher than that of implants located in the mandible (P < .01), except for the upper and lower canines. The logistic regression analysis indicated that the risk of the implants presenting inadequate KMW (<2 mm) in the periodontitis-caused tooth loss group was 1.91 times of the non-periodontitis-caused tooth loss group. The risk of implants presenting inadequate KMW after receiving simple and complex bone augmentation procedures was 1.65 and 2.62 times of the risk of implants without bone augmentation, respectively. The longer the follow-up period, the higher the risk of implants presenting inadequate KMW will be. CONCLUSIONS: The KMW at the buccal aspect of implants is related to the position of implants. Tooth loss due to periodontitis, the bone augmentation procedures, and the process of functional period would increase the risk of implants presenting an inadequate amount of keratinized mucosa.