Dental care costs are only reimbursed in connection with accidents. An accident always involves some surprising, external factor. If e.g. you break your tooth due to the presence of a pit in your food, it is an accident and the dental care is covered. However, if your tooth hurts due to an acute dental condition, this is not reimbursed under the travel protection scheme.
Such treatment as dental care that is required before a surgery may be compensated. Children’s dental care is compensated to the extent that any similar treatment is provided free of charge to minors in Finland.