The Effect of Maintenance Therapy on Clinical Parameters of Implants Supporting Maxillary Overdentures

Objectives: Dental implants have been used worldwide with high level of success and good documentation in literature. Despite these favorable results, few studies have evaluated clinical strategies to optimize long-term peri-implant hard and soft tissue health. Thus, the aim of this retrospective longitudinal study was to evaluate the impact of an annual maintenance therapy on clinical and radiographic parameters of implants supporting maxillary overdentures
Methods: Consecutive patients rehabilitated with maxillary four external hexagon implant-supported overdentures between 2008 and 2009 were asked to participate in this retrospective study. Patients were divided into two groups: group A - with patients enrolled in a maintenance care program including recall appointments every 12 months for the last seven years; and group B- with patients not enrolled in any maintenance care program. The following peri-implant parameters were evaluated: plaque index (PI), bleeding index (BI), probing depth (PD).
Results: Forty two patients (21 in group A and 21 in group B) with 168 implants were available for follow-up examination after a mean period of 7 years follow rehabilitation with implant-supported maxillary overdentures. No differences in implant survival rates were seen between the groups. An association between PI and maintenance was found (p=0,042). Likewise, an association was also found between BI and maintenance (p=0.034). In sharp contrats, peri-implant PD did not differed statistically between the groups (group A: PPD = 3.26 mm, group B: PD = 3.74 mm; p=0.104). A generalized estimating equation model was used to investigate potential associations between PD, BI, PI and enrollment in the maintenance care program. The main effect of plaque and bleeding were not significant (p-value = 0.0826 and 0.0724, respectively).
Conclusions: Within the limitations of this study, it can be concluded that a comprehensive maintenance protocol should be followed to ensure good plaque control and peri-implant tissue health.