Masticatory function and oral health-related quality of life of patients with atrophic and non-atrophic mandibles using implant-retained mandibular overdentures: 3-year results of a prospective clinical study.

Abstract

Long-term changes in masticatory function, oral health-related quality of life (OHRQoL) and prosthetic complications in implant-retained mandibular overdenture (IMO) wearers as a function of bone atrophy require detailed investigations. Investigating the evolution of masticatory function, OHRQoL and prosthetic occurrences of IMO wearers according to mandibular bone atrophy over 3years of usage. This study evaluated 26 IMO wearers after 2 and 3years of IMO loading categorised according to mandibular resorption degree into atrophic mandible (AM) and a non-atrophic mandible (NAM) group. Masticatory function was assessed by the Masticatory Performance (MP) and Swallowing Threshold (ST) tests; OHRQoL and satisfaction via the Dental Impact on Daily Living (DIDL) questionnaire; and the prosthetic maintenance requirements and complications were monitored. After the second year, the AM Group performed 32% more cycles (P=.047) than the NAM Group during the ST test. The DIDL questionnaire showed no significant difference for all domains, except for a moderate effect size in the General Performance domain after the third year. AM Group had more prosthetic occurrences (n=109) than NAM Group (n=60) in the first year, mainly due to Equator attachment dislodgment. During the third year, NAM Group presented a greater number of events (n=45) than AM Group (n=21) due to the greater number of O-ring exchanges. Masticatory function and OHRQoL are not related to mandibular bone atrophy until 3years after IMO rehabilitation. The prosthetic complications profile differs between groups, mainly in the first year.