The purpose of this study was to make a comparative analysis of dental question and answer in portal sites. To achieve this, 4,212 questions were used for final analysis after connecting to Naver, Daum and Nate, which take first, second and third place in rank information of all sites at Rankey.com, to search dental information by keyword from January to late March. The results are as follows. Naver was the highest as a portal of Internet search engines. Questions on the use of dental clinics, the quality of dental services and the offer of dental services by types of dental clinics were very important. Dental clinics had to give dental patients customized services and information to please them through dental services and dental information services on the Internet, and questions and answers on this were increasing very explosively. Consequently, Dental clinics will have to give Internet users and health- and disease-related data searchers distinctive professional services by inquiring into factors affecting portal search and factors affecting health- and disease-related search, respectively.