Tooth dryers are very practical, because it is necessary to keep your teeth dry when whitening or doing orthotics. When using a 3-way syringe, it is often stained in a humid environment and sometimes touched the surface of the teeth. The effects of the drug will be poor. Statistics, more than 50% of the dental clinics were affected by humid environment. After using a dental tooth air drier, the adhesive strength of the glue, tensile shear bond strength, and the resin adhesion effect. The nozzle can be sterilized up to 135° to prevent cross-infections between patients.