Laboratory assessment of the accuracy of the fit of artificial crowns to tooth stumps

Abstract

Relevance. Among the variety of reasons for unsatisfactory results of treatment of patients with artificial crowns and their premature removal or cementation, the researchers highlight the development of secondary caries. One of the significant reasons for its occurrence is the quality of the marginal fit of artificial crowns.
 The goal is to perform a laboratory assessment of the thickness of the cement film in the area of ​ ​ the edge of the artificial crown and establish the degree of its influence on the probability of the development of the carious process.
 Procedure. Splints of 50 freshly removed teeth covered with artificial crowns were made, on which the thickness of the cement film was measured, and the presence of caries at the edge of the artificial crown was determined.
 Results. The development of caries under the artificial crown is typical of teeth dissected with a ledge. The threshold value of the thickness of the cement film, above which caries more often developed in the studied sample of teeth, was 115-120 microns. The probability of unacceptable thickness of the cement film and the development of caries in teeth prepared with a shoulder is 6.6 times higher than in preparation without a shoulder.