Objective: To test the hypothesis that dental practice type is associated with how dentists treat existing restorations that may or may not have secondary caries. Methods: Dentists in “The Dental Practice-Based Research Network” (DPBRN; www.DentalPBRN.org) who do at least some restorative dentistry were surveyed (n=901). DPBRN is a consortium of dental practices that have affiliated to answer research questions and includes dentists from 3 practice types: public health clinic, solo/small private practice, and large group practices. Dentists indicated whether they would intervene in a series of cases portraying defective restorations. Each case included existing restorations with various levels of defects and a written description of a patient at a specific level of caries risk. We analyzed associations between intervention and dental practice type. Treatment options varied from no treatment to full replacement of the restoration. Preventive therapies were also included. Chi-square tests were used to analyze the relationships between treatment options chosen and type of practice. Results: 519 (58%) dentists responded. Differences based on practice type were found for the type of restorative material used on the existing restoration (composite versus amalgam) and the type of margin where the restoration was located (enamel versus dentinal margins). Irrespective of the type of margin and restorative material, dentists from solo/small private practice chose the replacement option more often than dentists from large group practices or public health clinics (p<.00001). For composite with dentinal margins, female dentists recommended combined preventive treatments more often than male dentists (p=.016). Dentists who routinely assess caries risk as a normal part of a treatment plan chose the repair and prevention treatment more often than dentists who did not (p=.02). Conclusion: Treatment options chosen by participating dentists when evaluating existin g restorations varied according to dental practice type and assessment of caries risk. Support: U01-DE-16746, U01-DE-16747.