Photocatalyst has two major effects: degradation of organic compounds and superhydrophilicity. These effects lead to the antimicrobial and self-cleaning effects. Photocatalyst has been applied for medical clinical practices. Two major oral diseases (dental caries and periodontal disease) globally influence on several billons of people. Treatment of oral diseases allows direct access to lesions in the oral cavity. And there are various advanced dental materials in dentistry. Therefore, photocatalyst can be a useful tool for dental clinical practice. The aim of this article is to summarize the research of application of photocatalyst for dental research and to find out the future prospective for photocatalyst to dentistry.