Brushing one's teeth is nearly as likely as removing a tooth to temporarily cause bacteria to enter the bloodstream, according to a report in the journal Circulation.
This finding is concerning because bacteria in the blood can lead to a rare, but potentially serious heart problem called infective endocarditis, the infection of the heart valves and chambers.
The risk of infective endocarditis with tooth brushing relative to dental procedures is unknown, Dr Peter B. Lockhart, from Carolinas Medical Centre in Charlotte, North Carolina, and colleagues note.
Although tooth removal is among the most likely of dental procedures to cause bacteria to enter the blood, tooth brushing can disrupt a larger amount of gum tissue.
How the study was done
To investigate these effects, Lockhart's group randomly assigned 290 patients scheduled for tooth extraction to tooth brushing followed by tooth extraction; tooth extraction with an antibiotic given beforehand; and tooth extraction with inactive "placebo" beforehand. None of the patients required antibiotics to prevent infection based on current guidelines.
Blood samples were drawn prior to tooth brushing or tooth extraction, then at 1.5, 5, 20, 40 and 60 minutes after the beginning of the procedures. Blood samples were cultured for bacteria.
Of 98 types of bacteria found in the blood samples, 32 were considered to be potential causes of infective endocarditis. One or more of these 32 microbes were found in 23 percent of patients in the tooth brushing group, 33 percent of those in the extraction/antibiotic group, and in 60 percent of those in the extraction-placebo group.
At the 60-minute blood draw, five percent of the extraction-placebo group and two percent of the brushing group still had potentially disease-causing bacteria in their blood.
These findings suggest that brushing poses a risk for bacteria in the blood similar to that of a dental extraction, the authors note, and that antibiotic treatment beforehand is only partially effective in preventing this. – (Reuters Health)