The different kind and operational modes of lasers irradiation have been compared to determine their effectiveness in inhibiting the formation of an in vitro incipient caries-like lesion. It is clearly indicated from these experiments that the acousto-optically Q-switched Nd: YAG laser might prove to be the most effective for clinical application. Laser irradiation was found not only to prevent but also cure incipient enamel caries without cutting lesions and restoring. This irradiation could also prevent the secondary caries at restoration margins with closing the space by fusion between the cavity margins and resinous restorations. The Nd: YAG laser was effective for treating sensitive root surfaces by closure of dentinal tubule apertures, and also for endodontic treatment by promating additional secondary dentin formation on pulp chamber walls.
This report discusses (1) achievements of public health and medical services activities since the founding of the People's Republic of China, (2) three major health and medical issues that must be tackled, and (3) the public health policies and measures of the Chinese government. The achievements of public health and medical services activities of Chinese government up to the present have been outstanding. For instance, the infant mortality rate has been reduced to less than one-tenth, and the life expectancy at birth has been greatly extended. Furthermore, the numbers of medical facilities, beds, and persons engaged in public health and medical services have increased greatly. In particular, there has been a remarkable decrease in the incidence of infectious diseases. One of the factors contributing to this decrease has been the introduction of periodic vaccine inoculations, which almost 100% of infants have received by the age of twelve months. The three major issues in public health and medical services that must be confronted are:(1) softening the impact of the switch to a market economy, (2) coping with the challenges of an aging society, and (3) reducing the gap in levels of health and medical services available in cities and rural areas. The Chinese government has established seven strategies for a public health policy geared to the new era of reform and liberation. These measures stress the prevention of diseases, as well as the promotion of health and medical activities with the full participation of all people in the nation, giving greater weight to rural areas. In addition, the government has decided to promote the establishment of financial resources for public health and medical care, reform of the medical insurance system, adjustment and improvement of medical care service systems, and the establishment of new laws governing medical care.