H.—3l

As the result of the experience gained with the mobile trailer clinic since it was placed on the road six months ago, it can be said that it makes for greater convenience of working, but that the first cost and the cost of operation (both of which have to be borne by the local committee) are considerably higher than in the case of a centrally situated stationary clinic. Prevention of Caries by Operative Methods. During recent years, the attention of the Service has been focused to a considerable extent on the preservation of the teeth by early attention to those pits and fissures where decay usually commences. The procedure that has been adopted is to open up all such pits and fissures to the minimum extent necessary to retain copper amalgam. This is done as soon as the teeth are sufficiently erupted, and before the onset of caries. Whenever it is found on opening up a tooth that caries is already established, a normal cavity preparation is followed, and the tooth restored by means of silver amalgam. The prophylactic copper amalgam fillings have a typical appearance, which is by no means displeasing. They show up black against the white enamel of the tooth as narrow clean lines following the course of the fissures, or else as small pin-head fillings. Their value in preventing major dental defects is undoubted, and, now that their use has become general in the School Dental Service, there has been a definite decrease in the number of silver amalgam fillings in permanent teeth. As the latter can be regarded as representing teeth that were definitely carious, it is obvious that the prophylactic fillings are having the desired effect. Admittedly this procedure has its limitations. For instance, it is not applicable to approximal surfaces. Nevertheless the experience of the Service is that, notwithstanding its being an operative procedure, it is of definite value as a preventive measure, and until such time as more is known regarding the role of diet in the prevention of dental caries, and the public is educated accordingly, prophylactic fillings will continue to fulfil a useful function.

A Clinic of the usual stationary Type.

Such, clinics are established in central positions, where the children from surrounding schools attend for treatment. (See map on page 48 illustrating the organization of dental "areas" and " groups.") Dental Health Education. During the year under review, an appeal was made to all officers in the Service for increased activity in the matter of dental health education, and the response was very encouraging. Whereas during the previous year talks and addresses numbered 286, this year they increased to 425. In addition to these more formal activities, chair-side talks, surprise dental inspections, and the distribution of leaflets were carried out as matters of routine procedure. It is interesting to note that during the year some 90,000 educational leaflets were issued to clinics for distribution to patients. It is impossible to assess the result of this activity, but it is hoped that the majority of the leaflets found their way into the homes, and that they came to the notice of parents. The work of a School Dental Service would show surprising results if only it were fully supported in the homes. The first leaflet to be issued as a routine is an invitation to parents to be present when their children are first examined. The value of personal contact and mutual understanding at that particular time is incalculable, and might well have lasting results as far as the dental health of a child is concerned. The result, however, is disappointing : the number of parents who accept the invitation is comparatively small. The last leaflet of the series is issued to the children when they pass out of

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