According to the third national epidemiological investigation on oral diseases conducted in 2005, the caries prevalence rate of children aged between 5-6 years old remains high, people of 35-44 and 65-74 years experience high caries prevalence rate and low filling rate [8] [9] (Table 6 ). With more teeth remaining in the oral cavity, the elderly are apt to develop caries and other oral disorders. Investigations conducted in Bejing and Shanghai have revealed that people aged between 65-70 years exhibit a root caries prevalence rate of 57%, a root caries index of 4.0-5.8, DFS index of 5.9-6.3 while 60%-70% of the fillings need replacement or have secondary caries underneath [8] [9] [10] [11] .