Various methods by means of which to eliminate or prevent the deposition of dental calculi have been reported and, as a preventive measure, the application of chemicals is being tried. As a step in this direction, the author investigated into the effects of a few proteolytic enzymes on the saliva so as to measure fluctuation in the amounts of Ca both in the supernatant and sedimentation and also to evaluate the proteolytic action of these enzymes on saliva protein in vitro condition.
At the same time, with use of a modified calculus depositing apparatus devised by Yankelowitz and others he mixed the saliva with a variety of proteolytic enzymes and quantitatively measured the deposits thus produced.
As a result of these studies, the author arrived at the conclusions as follow.
1. When fluctuational changes in the amount of Ca both in the supernatant and sedimentation of the saliva mixed with various proteolytic enzymes were observed in the pasage of time, it was found that Ca in the supernatant registered a decrease in the first one hour but suddenly increased in the six hours, beyond which the increase was gradual. On the other hand, Ca in the sedimentation increased proportionally till six hours and the increase then because quite gradual.
2. In terms of effects of the proteolytic enzymes on the amounts of Ca both in the supernatant andd artifically induced calculi, Ca in the supernatant was measured to increase chronologically in proportion to the amount of Ca in the latter.
On the other hand, Ca in the supernatant registered a decrease chronologically when a variety of proteolytic enzymes were added to it.
Rates of these proteolytic enzymes in preventing the dental calculi were in the range of 86% to 53%.
3. The effect of proteolytic enzymes on saliva protein was observed by measuring the amount of none-protein substances produced by supplement of these enzymes into saliva at intervals of one hour, six hours and twenty-four hours. As a result, it was found the amount of none-protein substances increased suddenly at the first one hour, beyond which, the increase was gradual, or no change was noted. On the other hand, in the case of Lysozyme the degree of increase was greater as compared to other enzymes.
On the strength of these experimental data, it may be supposed that, when a proteolytic enzyme is mixed with the saliva, Ca contained in the enzyme will be wrapped up by the protective glutamin action of the saliva protein and, though it deposits itself for a time, this action will be gradually decomposed in the passage of time, thus Ca in the absolute state being gradually transferred from the sediment to the supernatant.
This supposition is endorsed by another experiment in which the addition of a proteolytic enzyme apparently destroyed the agglutinating property of the saliva, with the result that a lesser amount of Ca adhered itself to it.
As a result of these studies, it is to be concluded that there exists a good possibility for the prevention of calculi from depositing on the dental surfaces by the application of proteolytic enzymes.