Among healthy adults in Sweden plaque build-up increased the relative risk of premature death 79%, Birgitta Söder, PhD, of the Karolinska Institutet in Huddinge, Sweden, and colleagues reported in BMJ Open.
The finding suggests that increased plaque and associated toxins and enzymes, may be released from the built-up biofilm and enter the bloodstream through the gingival crevice, thus increasing the risk of malignancies.
Dental Hygiene - Cancer Study
In 1985 Söder and colleagues initiated a longitudinal study of 1,390 randomly selected, healthy Swedish adults ages 30 to 40, who had no signs of periodontitis at baseline. The participants were followed with periodic checkups including smoking habits and oral health through 2009.
Dental plaque measures were taken at baseline and in 1996, 1998, 2000, 2001, and 2009.
Over the 24-year study period, 58 patients died, including 35 deaths due to malignancies.
Individuals still alive at the end of follow-up had a significantly lower dental plaque index than those who died (0.66 versus 0.87, P=0.001).
After multiple logistic regression analysis, the researchers found age, male gender, as well as the amount of dental plaque were principal independent predictors of mortality at follow-up. Age and male gender almost doubled the risk of dying prematurely .
The researchers added that there were statistically significant differences between living and dead patients "regarding the amount of dental plaque, gingival inflammation, and dental calculus, indicating a significantly poorer dental status in the subjects who died when compared with survivors."
The researchers said their hypothesis will require additional studies to determine whether any causal relationship can be derived from the association between poor oral hygiene and cancer mortality.
The study was funded by the Swedish Ministry of Health and Social Affairs, the Karolinska Institutet, the Finnish Medical Society, Helsinki, and Helsinki University Central Hospital.
Source: Söder B, et al "The association of dental plaque with cancer mortality in Sweden. A longitudinal study" BMJ Open 2012; 2: e001083; DOI:10.1136/bmjopen-2012-001083.