BackgroundThe objectives of this study were to compare oral frailty (OFr) among edentate and dentate older adults living in long-term care facilities (LTCF) and to clarify how edentulism and oral disease burden (ODB) of dentate older adults are associated with OFr.MethodsThe population of this study comprised 94 edentate and 209 dentate residents in LTCF in Helsinki, Finland, who had previously participated in a nutritional study. The participants underwent a clinical oral examination. The dentate residents were further divided into three ODB groups based on asymptotic dental score. The edentate and different ODB groups were compared with each other regarding demographics and oral and medical findings. OFr was defined as ≥ 2 of following: having a diet of soft/pureed food, residue of food in the oral cavity, inability to keep the mouth open during examination, unclearness of speech, dry mouth. The association between OFr and edentulousness and various levels of ODB was analyzed by a multivariate logistic model.ResultsParticipants with low ODB had significantly less OFr than their edentate peers (p = 0.009). Furthermore, the edentate and dentate with high ODB had similar odds for OFr.ConclusionsEdentulousness and high ODB are equally harmful conditions and may predispose to OFr. This study suggests that maintaining healthy natural teeth and good oral health (low ODB) may protect against OFr.Trial registrationThe Ethics Committee of the Hospital District of Helsinki and Uusimaa approved the protocols for the nutritional status and oral healthcare studies and the merging of the data, including patient medical records (Register number HUS/968/2017).