The Study of State of Hard Tooth Tissues Covered by Artificial Crowns Using Sections, in Long-term Follow up after Denture Treatment

The aim of the investigation is to study the state of hard tooth tissues under artificial crowns and the quality of their marginal seal long after denture treatment using the developed technique of obtaining tooth sections.Materials and methods. Extracted teeth covered by fixed orthopedic dentures were fixed in plastic blocks. Dental sections were obtained using lengthwise cut. The sections were scanned to obtain colour images. The parameters of hard tissues were assessed based on the images.Results. In 43.5% of the studied teeth covered by artificial crowns carious process was revealed long after the denture treatment in precervical area in more than half of the cases (55.5%). In the vast majority of cases (78%) there was no clear preparation boundary in precervical area, i.e. precervical shoulder formation. The obtained sections of 63% teeth had no proper attachment of the artificial crown edge to precervical part of the tooth. Linear preparation boundary formation, i.e. precervical shoulder, and the accuracy of fixed denture position were stated to be essential conditions to keep tooth hard tissues intact long after artificial denture treatment. The findings obtained make it possible to explain the inefficiency of fixed dentures long after denture treatment and develop measures to improve the quality of denture treatment.