A study recently conducted in Sweden suggests there may be a link between poor dental hygiene and a risk for cancer and premature death. The study, conducted by Birgitta Söder, PhD, of the Karolinska Institutet in Huddinge, Sweden, and colleagues, was reported in BMJ Open in June 2012. The objectives were to study whether the amount of dental plaque, which indicates poor oral hygiene and is potential source of oral infections, associates with premature death from cancer. At the conclusion of the 24 year study, the study hypothesis was confirmed by showing that poor oral hygiene, as reflected in the amount of dental plaque, was associated with increased cancer mortality.
The finding, the authors wrote, suggests that increased plaque and associated toxins and enzymes, may be released from the built-up biofilm in the mouth, and enter the bloodstream through the gingival crevice, thus increasing the risk of cancer.
Söder and colleagues began the study in 1985 by randomly selecting 1,390 healthy Swedish adults ages 30 to 40, who had no signs of periodontitis at baseline. These subjects were then followed for 24 years, until 2009. Each participant received periodic checkups, including assessment of information regarding general oral health and smoking. At the end of the 24 year period, those still living had a significantly lower dental plaque index than those who died. Statistically, a significantly poorer dental status, indicated by dental plaque, gingival inflammation, and dental calculus, was found among those that died during the study.
Söder and co-authors said their hypothesis will require additional studies to determine whether a causal relationship can be derived from the association between poor oral hygiene and cancer mortality.
You can read more details about this study here: The association of dental plaque with cancer mortality in Sweden. A longitudinal study.