Learning curves: what do dental students learn from repeated practice of clinical procedures?

It is generally accepted that repetition of procedures is necessary to develop clinical skill in dentistry. Although there is a rich empirical research tradition in medicine establishing competency levels for new procedures, investigations of the shape of learning curves for clinical techniques are rare in dental education. Data were reviewed from three classes (n=465) of students at the University of the Pacific Arthur A. Dugoni School of Dentistry in seventeen clinical skills in five departments for which test case (independent performance) data were available. It was hypothesized that a learning curve would be observed with gradually rising scores as a function of amount of repeated test case work and general practice experience. Other factors, such as faculty ratings and clinical GPA, could be expected to modify this curve. No evidence was found that test case performance was affected by number of previous test cases, number of practice (ungraded) procedures previously completed, faculty ratings of technical skill in the discipline by quarter, faculty ratings of patient management and of clinical judgment competencies, overall clinical GPA, and performance on initial licensure examinations. The absence of a pattern showing that amount of prior experience improves clinical performance raises questions about the practice of setting "requirements" for graduation and challenges dental educators to better explain the presumed relationship between practice and performance and the validity of clinical evaluation of performance based exclusively on the objective technical quality of work samples. The literature on learning curves and on competency-based education offer alternative insights into what students are actually learning but schools are failing to measure in the clinical experience.