Tooth hypersensitivity due to dental erosion is one of the most common problem related to swimming in improper pH chlorinated pools. Because the teeth are exposed to acidic water for a long time, which cause the loss of dental hard tissue. Tooth hypersensitivity can lead to a negative effect on daily life such as dietary selection, maintaining optimal dental hygiene and beauty aspects. It has been found that using mouthguard while swimming can prevent the teeth directly contact to chlorinated water, so it can protect tooth structure and decrease tooth hypersensitivity. Moreover, using mouthguard with viscous products can seal the gaps between mouthguard and teeth which can help to protect tooth structure and decrease dental hypersensitivity more effectively. At present, there are many desensitizing products such as toothpaste, mouthwash and chewing gum. Desensitizing toothpaste is the most common over-the-counter (OTC) materials in desensitizing. Many research has endorsed the properties of desensitizing toothpaste that can reduce tooth tissue loss and helps to reduce tooth hypersensitivity effectively. So it can be hypothesize that when use the combination of mouthguard with desensitizing toothpaste, it might have synergistic effect on reducing tooth hypersensitivity in swimmers.

Tooth erosion is the loss of dental hard tissue due to acidic agents without bacteria involvement.

Mouthguard is a protective appliance use for covering the teeth and gums to prevent the teeth from acidic chlorinated water.

Desensitizing toothpaste is toothpaste containing 8 percent arginine and calcium carbonate that can reduce tooth demineralization and promote remineralization.

Inclusion Criteria:

• Age 13-25 years (age under 18 years must obtain consent from parents)
• Swimming at least 5 hours/week
• Having tooth hypersensitivity from erosion
• Can read or understand Thai language

Exclusion Criteria:

• History of allergic to toothpaste
• Having any tooth which will affect to the tightness of mouthguard
• Having fixed orthodontic appliance