The work, published in the BMJ Open online journal, analysed 1,390 patients between 1985 and 2009, with results revealing that after 24 years, 58 patients had died.
Of these, 35 deaths were attributed to cancer and these people were seen to have a significantly higher amount of dental plaque when they were alive.
People who died from cancer scored between 0.84 to 0.91 on the plaque index, while the survivors had consistently lower scores of 0.66 to 0.67 - indicating only partial plaque coverage.
"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," stated the authors of the report.
They called for further research to be carried out.