Will implants with a fixed dental prosthesis in the molar region enhance the longevity of teeth adjacent to distal free-end edentulous spaces?

OBJECTIVES Clinical evidence demonstrating the effectiveness of implants in preventing tooth loss is limited because of the many risk factors involved in tooth loss. This retrospective cohort study investigated whether an implant in the molar region of a distal free-end edentulous space affects the loss of the most distal tooth after 6 years, adjusting for other risk factors associated with tooth loss using propensity score matching analysis. MATERIAL AND METHODS 571 subjects and 1085 teeth adjacent to a distal free-end edentulous space were evaluated. At baseline, the 1085 teeth were divided into two groups according to the presence or absence of a molar implant with a fixed dental prosthesis in the distal free-end edentulous space. Propensity score matching analysis was used to reduce the effects of bias by matching teeth with and without implants according to similar background factors at baseline. The adjusted variables were age group, occlusal support status, Kennedy classification, tooth position, tooth type, restoration status, dental caries, periodontal pocket depth, and condition of the opposing tooth. RESULTS 56 teeth (28 associated with a molar implant; 28 with no implant) were enrolled according to propensity score matching. Fisher's exact test showed that a molar implant significantly protected the tooth adjacent to the distal free-end edentulous space (p = 0.01). CONCLUSIONS Within the limitations of this retrospective cohort study, it was found that implants in free-end edentulous spaces may be beneficial in extending the longevity of adjacent teeth. Further research will be necessary to confirm this finding.