Non-carious (NC) defects on tooth surfaces are common clinical occurrences that may require restorative treatment. A better understanding of the reasons for placement of restorations on NC surfaces can provide useful guidance on treatment planning and management strategies as well as on trends of dental materials usage. Objective: To quantify factors that Dental Practice-Based Research Network (DPBRN; www.DPBRN.org) clinicians utilize to restore NC defects. DPBRN comprises practices from five regions: AL/MS: Alabama/Mississippi; FL/GA: Florida/Georgia; MN: dentists employed by HealthPartners and in private practice from the Minneapolis, Minnesota area; PDA: Permanente Dental Associates in cooperation with Kaiser Permanente Center for Health Research; and SK: Denmark, Norway, and Sweden. Methods: Data were collected regarding 8756 consecutive restorations in un-restored permanent tooth surfaces by 195 practitioner-investigators. Information included the criteria for restoring and the dental material used by restoration class. Results: Of all restorations, 7558 (86%) were done due to primary caries and 1198 (14%) were done due to NC defects. Reasons for placement of restorations included tooth fracture (33% of total NC); erosion, abrasion, or abfraction (26%); cosmetic reasons (15%); developmental defect or hypoplasia (6%); and restoration of endodontically-treated tooth (4%). Cervical Class V (49%) lesions were the most common, followed by Class IV (17%), Class II (16%), Class I (11%), and Class III (7%) NC restorations. Class V lesions were mainly restored with composite resin (88%). Indeed, direct composite resin (82%) with resin-based bonding material was the primary material used in all NC restorations, except for Class II preparations (36%), where amalgam was just as frequent. Amalgam restorations were often preceded by none or different base-liner materials. Conclusion: Although the etiology of non-carious cervical defects is not well understood, these lesions are frequent and most commonly restored with composite resin materials by DPBRN practitioner-investigators. Support: NIDCR-NIH U01-DE 16746 and 16747.