Abstract
The problem of intramural infection has come to claim our attention in hospitals and dental clinics, and the importance of sterilization and disinfection has been given a new emphasis. In actual dental practice, the admixture of various substances adversely affects the antibacterial effect of disinfectants. These various substances include tooth cutting powders, alginate impression-taking material, saliva, serum, resin for immediate polymerization, and zinc phosphate cement. For this reason, in the present study, these materials were mixed with various disinfectants that has been diluted to 900 to 1024, 00 times (chlorhexidine, benzalkonium chloride, cresol, and irgasan DP-300) and a series of experiments were carried out to study the influences on their antibactrerial effects.
The following were the salient results obtained from the present study.
1. The substances that particulaly reduced the effects of these disinfectants were tooth cuttings, alginate impression-taking material, and serum.
2. The sterilized saliva, either 1) reduced the antibacterial effect, 2) increased it or 3) had no influence at all.
3. Resin powder, sometimes reduced the antibacterial effect and sometimes not.
4. Dental cement powder either increased the antibacterial effect or had no influence at all.
5. Resin and dental cement liquid did not cause an increase in the growth of bacteria at any concentration.
6. The effect of saliva samples collected from 12 subjects, showed wide individual differences. Cresol was the most prominent by offected, followed by irgasan DP-300. The influence on chlorhexidine and benzalkonium chloride was more or less the same.
7. The pH values of the admixtures of various substances were pH 2.2 in the case of a dental cement, and from pH 7.1 to 7.4 in the case of the other substanses.
