The future health-care workforce and the changing skill-mix within occupational teams is a current topic of discussion. This paper contributes to the skill-mix debate by focusing on UK primary care dentistry, revealing unintended as well as intended consequences of a modularized, technocratic view of dentistry. In part one, relevant literature about dental therapists and skill-mix in dentistry is organized into a framework used to review factors operating at macro, meso and micro levels. Part two considers the role that education and training may play in realizing skill-mix change. Part three synthesizes conditions required for modifying skill-mix in UK primary dental care and sets out the dimensions of seven factors: funding focus, the profession's response, workforce, the practice, dentist's knowledge, dental therapist's motivations and patient attitude. A review of these factors could be used to inform the policy decisions of managers operating at the macro level, as well as more local staffing decisions. Without consideration of the complex interplay of these factors, skill-mix in dentistry will be slow to develop and could bring unwelcome consequences.