Comparing the magnitude of oral health inequality over time in Canada and the United States.

There was persistent absolute and relative inequality in Canada and the United States. An increase in relative inequality for adverse outcomes suggests that improvements in oral health were occurring primarily among the rich, while reductions in relative inequality for filled teeth indicate higher utilization of restorative services among the poor. These results point to the necessity of tackling the sociopolitical determinants of health to mitigate oral health inequality in Canada and the United States.