F. Schwendicke, L. A. Foster Page, L. A. Smith, M. Fontana, W. M. Thomson, S. R. Baker

This study aimed to identify barriers and enablers for dentists managing non-cavitated proximal caries lesions using non- or micro-invasive (NI/MI) approaches rather than invasive and restorative methods in New Zealand, Germany and the USA. Semi-structured interviews were conducted, focusing on non-cavitated proximal caries lesions (radiographically confined to enamel or the outer dentine). Twelve dentists from New Zealand, 12 from Germany and 20 from the state of Michigan (USA) were interviewed. Convenience and snowball sampling were used for participant recruitment. A diverse sample of dentists was recruited. Interviews were conducted by telephone, using an interview schedule based on the Theoretical Domains Framework (TDF). The following barriers to managing lesions non- or micro-invasively were identified: patients' lacking adherence to oral hygiene instructions or high-caries risk, financial pressures and a lack of reimbursement for NI/MI, unsupportive colleagues and practice leaders, not undertaking professional development and basing treatment on what had been learned during training, and a sense of anticipated regret (anxiety about not restoring a proximal lesion in its early stages before it progressed). The following enablers were identified: the professional belief that remineralisation can occur in early non-cavitated proximal lesions and that these lesions can be arrested, the understanding that placing restorations weakens the tooth and inflicts a cycle of re-restoration, having up-to-date information and supportive colleagues and work environments, working as part of a team of competent and skilled dental practitioners who perform NI/MI (such as cleaning or scaling), having the necessary resources, undertaking ongoing professional development and continued education, maintaining membership of professional groups and a sense of professional and personal satisfaction from working in the patient's best interest. Financial aspects were more commonly mentioned by the German and American participants, while continuing education was more of a focus for the New Zealand participants. Decisions on managing non-cavitated proximal lesions were influenced by numerous factors, some of which could be targeted by interventions for implementing evidence-based management strategies in practice.