Comparison of Carbon Dioxide versus Refrigerant Spray to Determine Pulpal Responsiveness

There is little evidence for which cold delivery method is most accurate in determining pulp responsiveness. This study compared carbon dioxide dry ice sticks (CO₂) versus refrigerant spray (RS) to generate a patient response from different types of teeth restored to varying degrees. Fifteen human patients were selected. In each quadrant, three teeth were identified and the restoration type recorded. Blindfolded patients were randomly tested with either CO₂ or RS in a crossover design at two different sessions. Responsiveness was recorded as yes/no and the interval (in seconds) from application to response was determined. Results showed that (a) CO₂ and RS were equivalent in producing a pulpal response regardless of tooth and presence of restoration, and (b) CO₂ took significantly (p < 0.05) longer to evoke a response than RS using paired t tests. In conclusion, RS and CO₂ were equivalent in determining pulpal responsiveness, but the elicited response from RS was faster.