This review consists of a short history of toothbrush efficacy trials plus recent literature on test methods of newer brush designs. Effects of handle size, bristle trim arrangement and size, brush head design, and brushing methods are considered. Methods for detecting and measuring plaque, particularly on critical surfaces, are reviewed, as are the influence of brushing time, method, and exerted force. Testing protocols, including plaque indices, tooth selection, and subject compliance, can produce large differences in results. Testing conditions must be carefully selected and controlled to obtain reproducible results.