Effect of Repeated Sterilization on the Tensile Strength of Rubber Dam Clamps.

PURPOSE: The fracture of rubber dam clamps after repeated clinical uses can result in ingestion/aspiration of the fragments. This pilot study was aimed at examining whether the tensile strength of a rubber dam clamp changes significantly following the stresses of repeated clinical use and steam sterilizations.

METHODS: One-hundred new stainless-steel rubber dam clamps were subjected to repeated steam sterilization and placement on a wooden dowel periodically, simulating clinical use. Two clamps were randomly selected for removal after every 50 sterilization cycles. Three-hundred such cycles were completed. Using a standard bench top universal tensile testing system (MTI-2K) a tensile force was applied to break the new clamps and the clamps that were stretched and autoclaved. The maximum force was recorded, and data analyzed using simple mean. The mean tensile load values were plotted on a graph against the number of sterilization cycles to analyze trends in the data.

RESULTS: The rubber dam clamps demonstrated a higher tensile strength and fracture resistance after three-hundred cycles of use and sterilization.

CONCLUSION: Repeated use and steam sterilization up to three-hundred cycles did not adversely affect the tensile strength of the rubber dam clamps. The clamps, in fact, demonstrated a higher tensile strength.