Although there is now a large evidence-based dentistry literature, previous investigators have shown that dentists often consider research evidence irrelevant to their practice. To understand why this is the case, we conducted a qualitative study. Objective: Our aim was to identify how dentists define evidence and how they adopt it in practice. Methods: A qualitative study using grounded theory methodology was conducted. Ten dentists working in eight dental practices were interviewed about their experience and work processes while adopting evidence-based preventive care. Analysis involved transcript coding, detailed memo writing, and data interpretation. Results: Findings revealed that dentists' direct observations--referred to as clinical evidence--provided the most tangible and trusted evidence in practice and during discussions with colleagues. Dentists described a detailed process used to gather, compare and implement clinical evidence. This process began when they were exposed to novelty in daily practice and proceeded through self-driven testing, producing clinical or tangible evidence that clinicians could use in practice. Conclusion: Based on these findings, we propose an alternative to the linear form of knowledge transfer commonly represented in the literature. (Contains 2 tables and 2 figures.)