Objective: The purpose of this study was to compare a single-use, disposable, presterilized light activation probe with an equivalent autoclavable probe. Light output, heat generation, and depth of cure were investigated. Method and materials: Ten disposable and two reusable probe tips were tested. Three maximum light output readings for each tip were recorded with a radiometer. Heat genertion at the probe tip was recorded, at 30-second intervals over a five-minute period, with a thermocouple probe placed under a 3-mm-thick glass slide. After light-activated compomer was placed in a sectional two-piece stainless steel mold and cured, depth of cure was evaluated using the scrape technique. Results: With respect to light output and depth of cure, there were no statistically significant differences between probe types, but the disposable probe generated significantly less heat. Conclusion: The disposable probe performed clinically as well as an autoclavable counterpart with respect to light output, heat generation, and depth of cure.