A clinical survey of 1466 children of typical South African communities showed a prevalence rate of primary tooth trauma of 15%. Trauma was least common at age 1-2 years (10.7%) and most common at 4-5 years (20.6%). The commonest trauma seen was fracture of enamel only (71.8%) followed by fracture of dentine (11.2%), tooth loss (8.2%) and discolouration without other sign of injury (5.6%).

Dentifrice usage studies were made in a group of 44 Edinburgh children aged between 3 and 6 years using a gravimetric technique based on the polishing agent in the dentifrice. The amount of paste apparently swallowed during brushing averaged 0.5 g or less for 70% of the subjects; the worst performer apparently swallowed an average of 1.16 g per brushing. In contrast to previous studies employing a urinary or faecal marker which will underestimate the amount ingested if samples are lost, the present technique will overestimate the amount ingested under these circumstances. Hence the true picture probably lies between the two sets of results.

Previous studies have shown that fluoride is present in beverages prepared with fluoridated water. The purpose of this study was to determine the availability of fluoride from beverages consumed in adjacent fluoridated and non-fluoridated communities taking into account fluoride supplementation regimens. Children in grade six were invited to participate in recording of beverage intake in two cities in Alberta, Canada: Wetaskiwin, with water supplies fluoridated at 1.08 ppm F, and Camrose, non-fluoridated with water supplies at 0.23 ppm F. Three-day beverage intake records--"Drink Diaries"--were collected from 179 children in Wetaskiwin and 230 children in Camrose. Fluoride values, based on the analyses of Hargreaves, were assigned to the reported consumption of the children with the three highest and three lowest total beverage intakes in each community. A wide range of available fluoride was found. A substantial source of fluoride was shown to be available in the non-fluoridated community from beverages other than water, primarily from carbonated beverages commercially prepared with fluoridated water. Available beverages and actual consumption should be considered in the prescription of fluoride supplementation for children with minimal fluoride in their drinking water.

A study was undertaken to examine the release of calcium and phosphate from cheese during mastication. Unstimulated saliva was collected for baseline analysis in the initial study followed by saliva collection after chewing different cheeses with and without biscuits. In the second study, volunteers who had abstained from toothcleaning for 24 h had plaque samples taken from two quadrants, they then chewed cheese in their own personal eating manner, and a second sample of plaque was taken within 5 min. The results showed that the calcium ion concentration of the oral fluids rose from a mean of 30 μg/ml to between 200 and 540 μg/ ml, depending on the type of cheese, but the phosphate concentration fell below baseline. The release of both ions tended to be less when the cheese was eaten with a biscuit. In the second study a highly significant rise in plaque calcium concentration was shown after eating cheese, but no consistent change in phosphate level was found. Acidic soft drinks, following eating, tended to reduce the plaque calcium levels, but no consistent change was found if tea or coffee was taken following the cheese consumption. It is suggested, from these findings, that cheese eaten alone at the very end of a meal raises plaque calcium and might be effective in reducing dental caries.