The effects of power toothbrushing on C-reactive protein levels in nursing home residents: A randomized controlled trial

The World Health Organization predicts that, between 2015 and 2050, the proportion of the world population over 60 years will nearly double, rising from 12% to 22%.1 Similarly, the proportion of Canadians 65 years and older is projected to rise from 14% to 25% by 2036.2 In addition to these population projections, nursing home (NH) residents' degree of illness has increased notably in recent years,3 and researchers have suggested the demand for NH use will increase considerably in future years.3,4 In 2012, Matthews and colleagues reported that 66% of Canadian NH residents had periodontal disease.5 Similar findings were reported by Compton and Kline in a student assessment of the oral status of residents of chronic care facilities in 2015.6 Although caregiver staff are responsible for daily oral care, several studies7-9 including a recent systematic review10, have reported the oral health of NH residents is in many instances deplorable, not only in Canada but worldwide. A speculated role of CRP may be in foam cell formation during atherogenesis and, as such, it is considered an important cardiovascular risk predictor.16,17 This literature has been derived almost exclusively from within the general population.11-17 No studies on NH residents exist other than those that examine associations between oral health and aspiration pneumonia.18,19 Numerous community-based oral health studies have shown reductions in overall CRP values following a variety of oral interventions.20-25 Additionally, several researchers have reported improved oral health to be associated strongly with improved cardiac function among community-dwelling people,22-27 and also with a reduction of aspiration pneumonia in NHs.18,19 To date, however, there is no evidence of the extent to which reductions in oral inflammation due to improved oral care are associated with reductions in systemic inflammation among NH residents. Within-person differences in CRP levels were analysed using the Wilcoxon Signed-Rank Test.36 This test is typically used as an alternative to the paired student t-test for matched pairs or the t-test for dependent samples, when the population cannot be assumed to be normally distributed.36 The Kruskal-Wallis non-parametric test was then used to determine if the overall amount of change varied significantly between study groups.37 This rank-based test may be used on independent variables that are either continuous or ordinal.37 All tests of statistical significance were set