Abstract
The purpose of this study is to survey the use of interdental brushing, especially choice and the most effective method of removing plaque.
The relationships between the various interdental brushes (.Φ) and the interdentalspaces (. Φ) required by its use were evaluated on models. The diameter (A 2) of bristle axis which folded around the metal axis was a good parameter for indicating this relation.
Each interdental brush needed a space of 1. 3-1. 6 times its own diameter of A 2 when the brush was inserted at a right-angle to the dentition and moved back andforth horizontally (1direction), and needed 1. 6-2. 0 times its own diameter when the brush was inserted obliquely from an apical direction and moved along each gingivel margin (4directions), statistically.
We also surved the interdental spaces of 457 sites on 20 persons with healthy gingivae and without attachment loss. The available interdental space (Φ) was 0. 8±0. 22mm. There were no significant differences between upper and lower, or left and rightjaws.
However, the characteristic distribution of the spaces was taken when the spaces were divided in to three blocks according to the type of tooth adjacent to the space (. Φ: premolararea>incisorarea> molararea).
In 41 percent of these 457 sites, we could not use the interdental brush (A 2: 0. 5mm). The average Φ of these spaces was0.6±0. 15mm.
Therefore, we guessed the minimum interdental brush needed to be 0. 3-0. 4 mm of A 2 by the calculation using the relationship between the brush and the space.
Plaque removal ability was also evaluated on the models with artificialCrO3 plaque. Increasing the direction of brushing brought about an increasing ability to removal plaque. About 50 percent of interdental plaque was removed by the 1 direction brushing, 77 percent was removed by brushing in 2 directions and 93 percent was removed by brushing in 4 directions. The interdental brushing in 1 direction was suitable for narrow spaces, because of their plaque removal percentage was more stable than that for wide spaces, whereas 4 directions brushing was suitable for the wider spaces.
For the same size interdental space, 4 directions with a relatively small size (A 2) of interdental brush were suitable for this space rather than the 1 direction with the relatively large size.
Based on the above results, we can say there are distinct brushing methods for the interdental brush, as for the tooth brush. We should consider the proper size and the brushing direction for each patient and each interdental space. And, if we can make a smaller size of interdental brush (A 2: 0. 3-0. 4mm), it will facilitate the removal of interdental plaque through out the dentition, even in healthy gingiva. It might also prevent the initiaion of perionontal disease.
