Randomized cross-over study investigating the tolerability and side effects of an intra-oral air-cooling device compared to ice in healthy volunteers.

Oral cryotherapy (OC) is a common preventive treatment of oral mucositis (OM) and is recommended in international guidelines. Ice and air OC have previously been shown to result in temperature reductions of 8.1-12.9 °C, and 14.5 °C, respectively, in healthy volunteers. However, no direct comparison between these two modalities has been performed. The primary aim was to investigate the tolerability and side effects of air OC using an intra-oral air-cooling (IOAC) device compared with ice OC. The secondary aim was to evaluate the temperature reduction in the mouth for the two respective methods. Cross-over study with randomization to order of treatment, in 15 healthy volunteers. We evaluated the self-reported intensity, frequency, and discomfort for 13 pre-defined side effects used in previous studies. All participants were able to complete both OC sessions, although one participant required reduced airflow in the air OC arm. The subjects reported more discomfort from being cold, having sensitive teeth, and numbness in the ice OC group, while they reported more discomfort from swallowing when subjected to air OC. No significant difference in the median temperature reduction was detected in the two modalities, except for the dorsal posterior part of the tongue where temperature reduction was larger in the ice OC group. We found that oral cooling using a new IOAC device was tolerated and seems to be safe in healthy volunteers.