Association between xerostomia and peri-implant health: A retrospective cohort study

Dental implants are a long-term and reliable solution to replace missing dentition, but subject to different patient-related and biological changes that could alter its success. Xerostomia, or the alteration of the normal salivary flow, can impair oral function and potentially affect the success of any treatment, including implant outcomes. The purpose of this study is to study the association between xerostomia and peri-implantitis.

A retrospective cohort study was conducted using records of patients who received dental implants between 2010 and 2023 at the University of Michigan School of Dentistry. The patients were divided into two groups: the xerostomia group and the non-xerostomia group. Implant level assessment included the presence of peri-implantitis and marginal bone loss, restoration type, cement-retained or screw retained, and the depth of restoration margin. Patient-level assessment included sex, age, smoking history, medical conditions, and maintenance visit frequency. Univariable and multivariable mixed-effects logistic regression analyses were performed to assess the association between peri-implantitis and patient-level and other implant-related variables. Odds ratios with 95% confidence intervals were reported, and statistical significance was defined as p < 0.05.

A total of 173 patients were included, with 46 patients reporting xerostomia. The results showed no independent association between xerostomia and peri-implantitis in either univariable or multivariable analyzes. The history of periodontitis and cement-retained restorations were significant predictors for peri-implantitis. Age was significant in univariable analysis but lost significance in the adjusted model. The frequency of maintenance visits was associated with peri-implantitis in univariable analysis but lost significance in multivariable analysis. Sex, smoking, and diabetes mellitus were not significantly associated with peri-implantitis.

Xerostomia alone does not increase the risk of peri-implantitis. A history of periodontitis, the use of cement-retained prosthesis, and longer follow-up duration after prosthetic loading were associated with unfavorable implant outcomes.