Study	Reason for exclusion
Gordan 2006	Participants were not randomised to treatment groups (prospective cohort study). Specified in their papers that randomisation was not possible across all treatment groups due to difficulty in obtaining IRB approval for randomisation; they only randomised when the options were to replace a restoration or provide no treatment.
Moncada 2006	Participants were not randomised to treatment groups (prospective cohort study). Participants assigned based on defect type. (Authors were contacted for clarification.)