Objective The purpose of this prospective study was to investigate whether poor oral health predicted eight-year cognitive function change in predominantly late middle adults in the Atherosclerosis Risk in Communities (ARIC) study. Methods Participants included a subset of ARIC participants aged 52–75 years at 1996–1998 from two study sites: Forsyth County NC and Jackson MS. All subjects completed cognitive function assessments both in 1996–1998 and 2004–2006, and the same subjects received a dental examination at the initial visit. Cognitive assessment consisted of Delayed Word Recall (DWR), Digit Symbol Substitution (DSS), and Word Fluency (WF) tests. In the analysis, cognitive function for 911 dentally screened participants was evaluated, and 558 of 785 dentate participants received comprehensive oral examinations, including periodontal probing. Measures of oral health included dental status, number of teeth, and periodontal disease classified by the Biofilm-Gingival Interface (BGI) index. The generalized estimating equations (GEE) method was used to analyze repeated measures of cognitive scores with adjustment for socio-demographic characteristics and cardiovascular risk factors. Results Of 911 study participants, 13.8% were edentulous. About 13 % of dentally examined participants had periodontal pockets (≥4 mm) with severe bleeding. At the follow-up visit, DWR and WF scores were lower in edentulous compared to dentate people, whereas other oral health measures were not associated with cognitive function. Mean values declined over time for all three cognitive measures, although poor oral health conditions were not associated with greater degree of decline in cognitive function. Conclusions In these late-middle aged adults, complete tooth loss was significantly associated with lower cognitive performance. However, neither edentulism, number of teeth, nor periodontal disease predicted greater subsequent cognitive decline.

Even before dementia becomes apparent, cognitive decline may contribute to deterioration in oral health. This cohort study of middle-aged adults evaluated associations of six-year change in cognitive function with oral health behaviors and conditions in the Atherosclerosis Risk in Communities (ARIC) study. Cognitive function was measured at study visits in 1990-1992 and 1996-1998 with three tests: (a) Delayed Word Recall (DWR), (b) Digit Symbol Substitution (DSS), and (c) Word Fluency (WF). Cognitive decline scores were computed as 'studentized' residuals of 1996-1998 scores regressed against 1990-1992 scores. In 1996-1998, 10,050 participants answered dental screening questions, and 5,878 of 8,782 dentate participants received a comprehensive oral examination. Multiple regression models used cognitive change to predict oral health behaviors and conditions with adjustment for covariates. In the fully adjusted models, greater decline in all three measures of cognitive function was associated with increased odds of complete tooth loss. Greater decline in DSS and WF scores was associated with infrequent toothbrushing. Decline in WF scores was also associated with higher plaque levels. In these middle-aged adults, six-year cognitive decline was modestly associated with less frequent toothbrushing, plaque deposit, and greater odds of edentulism, but not with other oral behaviors or diseases.

Objective To investigate whether oral self-care function mediates the associations between cognitive impairment and caries severity in community-dwelling older adults. Background Cognitive impairment significantly affects activities of daily living and compromises oral health, systemic health and quality of life in older adults. However, the associations among cognitive impairment, oral self-care capacity and caries severity remain unclear. This increases difficulty in developing effective interventions for cognitively impaired patients. Materials and methods Medical, dental, cognitive and functional assessments were abstracted from the dental records of 600 community-dwelling elderly. 230 participants were selected using propensity score matching and categorised into normal, cognitive impairment but no dementia (CIND) and dementia groups based on their cognitive status and a diagnosis of dementia. Multivariable regressions were developed to examine the mediating effect of oral self-care function on the association between cognitive status and number of caries or retained roots. Results Cognitive impairment, oral self-care function and dental caries severity were intercorrelated. Multivariable analysis showed that without adjusting for oral self-care capacity, cognition was significantly associated with the number of caries or retained roots (p = 0.003). However, the association was not significant when oral self-care capacity was adjusted (p = 0.125). In contrast, individuals with impaired oral self-care capacity had a greater risk of having a caries or retained root (RR = 1.67, 95% CI 1.15, 2.44). Conclusion Oral care capacity mediates the association between cognition and dental caries severity in community-dwelling older adults.