[The disinfection efficiency comparison of different treatments on dental impression and gypsum casts].

OBJECTIVE

In this study, the disinfecting efficiency of five disinfecting methods to three bacterial: Staphylococcus epidermidis, Streptococcus sanguis and Bacillus subtilis were evaluated.

METHODS

Germ free impressions and gypsum casts were divided into three teams contained 16 impressions and 5 gypsum casts for each one. Each team was smeared with each one of the three bacterial solutions. Then four disinfecting methods were administrated on these impressions separately, 2% glutaraldehyde immersion, 2% glutaraldehyde spray, 5% Eric immersion, 5% Eric spray. And ozone treatment was administrated on gypsum casts. Control teams were set up. After the treatment the impressions and gypsum casts were sampled at standard sites. The colonies were counted after culture and were used to deduce the germicidal ratio as the standard of disinfecting efficiency.

RESULTS

There was no difference between the efficiencies of five disinfecting methods for Streptococcus sanguis and Staphylococcus epidermidis. But for B. subtilis, the immersion methods have the highest efficiency among the methods and the ozone treatment has the least efficiency.

CONCLUSION

2% glutaraldehyde immersion, spray, 5% Eric immersion, spray are all effective disinfecting methods for impressions and ozone treatment is an effective method in disinfecting the gypsum casts.