No abstract

Two groups of children, ages 12 to 15, rinsed daily for 28 mo with aqueous fluoride solutions, one group using 0.05% sodium fluoride (NaF) and the other group using 0.1% stannous fluoride (SnF2). The SnF2 group had less plaque accumulation after four mo, but no difference was apparent at 16 and 28 mo. Gingivitis was less severe in the SnF2 group throughout the study, although the difference did not reach statistical significance. The 0.1% SnF2 solution, used daily as a mouthrinse, inhibits plaque formation, although this inhibitory effect is not apparent after 16 mo of rinsing.

Material from 20 young rhesus monkeys was prepared for study of the interdental gingival epithelium. An additional four young monkeys were injected with tritiated thymidine and radioautographs prepared for analysis of cell turnover. It was found that the interdental gingiva between recently erupted teeth in proximal contact has a col form. The appearance of the col can be simulated by vertical sections close to the roots of single teeth. Analysis of sections through the actual col showed that it is always lined by squamous epithelium, five or more cell‐layers thick, without any recognizable ameloblasts. The radioautographs showed consistent evidence of thymidine uptake, indicating cell‐division, in all epithelia lining the col. It was concluded that the histological features and turnover‐rate of epithelium in the interdental region are closely analogous to those of epithelium on other aspects of the teeth. Clinical studies of the presence and amount of plaque and gingivitis in 1,075 intact interdental areas in 48 young adults showed a high degree of correlation between the presence and amount of plaque and the presence and severity of gingivitis, and lend support to the hypothesis that gingivitis starts interdentally because plaque accumulates there.

The aim of this study was to compare the effects of daily mouthrinsing with aqueous solutions of 0.05% NaF or 0.1% SnF2 on dental caries and tooth staining. The study population consisted of 437 children, aged from 12 to 15 years at baseline, residing in a non-fluoridated community. By stratified random sampling, the subjects were divided into two groups, one group rinsing daily under supervision for 28 months with the NaF solution and the other with the SnF2 solution. The SnF2 group exhibited four to five times as much extrinsic stain as did the NaF group, although the stains were quite mild and not explicitly distinguishable between groups. There were no statistically significant differences between the two groups in terms of total DMFS. However, the increment of pit and fissure caries was 0.9 surfaces fewer for the SnF2 group (p = 0.04), while the increment of smooth surface caries was 0.6 surfaces fewer for the NaF group (p = 0.04). These data suggest that there may be a difference in mechanism of action between SnF2 and NaF rinses.