MedWire News: Poor oral health is associated with cancer mortality, show study results from Sweden.
In a cohort of randomly selected participants aged 30-40 years who were initially examined for periodontal disease in 1985, those with more dental plaque were more likely to have died from cancer by 2009 than their peers who had better oral health.
Furthermore, Swedish population demographics indicate that the women in the study who had died were expected to live a further 13.1 years, and the men 8.6 years, indicating that their deaths were "premature," write the researchers in BMJ Open.
"Based on the present findings, the high bacterial load on tooth surfaces and in gingival pockets over a prolonged time may indeed play a role in carcinogenesis," say Birgitta Söder, from the Karolinska Institute in Huddinge, and colleagues.
"Therefore, the control of oral biofilm, in order to reduce the burden of the microbial noxa from the mouth, seems important to combat this development," they add.
The team notes that further studies are required to confirm a causal link between their observations; however, they believe the random nature, longitudinal prospective design, and multiple adjustment of results in their study increase their reliability.
The study cohort included 1390 individuals who had no signs of periodontal disease at the 1985 examination. By the 2009 follow up, 58 participants had died, 35 as a result of cancer.
The oral hygiene status - measured by the plaque index (PLI) - of those who had died was significantly worse than for those who were still alive in 2009, at 0.87 compared with 0.66, indicating that the survivors' gingival region was only partially, rather than fully covered with plaque, remark Söder et al.
Furthermore, multivariate analysis, adjusted for variables including gender, age, education level, and income, showed that dental plaque was associated with a 1.79-fold increased risk for death by 2009.
The researchers explain that while participants had no sign of periodontal disease at the 1985 oral examination, they had had a "voluminous oral biofilm... covering the gingival crevice."
Tooth surfaces are not self-cleaning, they add, remarking that the oral biofilm must be removed by cleaning the teeth. Therefore, if cleaning is neglected, toxins released from the biofilm may eventually enter the blood circulation and spread throughout the body with "potentially systemic consequences."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012