This study aimed to assess the influence of an oral hygiene intervention on oral health, depending on the degree of dementia. A clinical evaluation of oral health parameters (index of decayed, missing, and filled teeth (DMFT-index), periodontal screening index (PSI), oral hygiene index (OHI), and bleeding on probing (BOP)) was performed in 120 subjects assigned to five groups, based on the mini mental state examination (MMSE) at baseline and after 12 months. Each MMSE group (no dementia (noDem, MMSE 28-30), mild cognitive impairment (mCI, MMSE 25-27), mild dementia (mDem, MMSE 18-24), moderate dementia (modDem, MMSE 10-17), and severe dementia (sDem, MMSE ≤ 9)) was split into control (no intervention) and experimental groups (intervention on oral hygiene: increased frequency, daily usage of high-fluoride toothpaste). In total, 99 out of 120 subjects were included in the analysis. The dropout rate was high in subjects with modDem and sDem due to death. In subjects with noDem, mCI, and mDem, no changes in the DMFT were found, but improvements in the OHI, BOP, and PSI were observed. Subjects with modDem or sDem demonstrated a deterioration in DMFT; however, in these patients, OHI improved in all control and experimental groups, BOP improved in the experimental group only, and PSI did not improve at all. The scope of improving oral health parameters by increasing the recall frequency and by continuously using high fluoride toothpaste is at its limits in people with severe dementia. Multidimensional approaches should be sought to improve the oral health of vulnerable older patients.
Keywords: DMFT; bleeding on probing; cognitive impairment; dementia; geriatric dentistry; old; oral health; oral hygiene index; oral hygiene intervention; periodontal screening index.