The establishment of various dental prostheses and devices primarily involves obtaining accurate and robust working model of the jaw.
A model is a sample for the manufacture of any product, accurately reproducing the shape of the last.
The model of the jaw is an exact reproduction of the surface of the hard and soft tissues located on the prosthetic bed and its boundaries.
The term “orthopedic bed” uniting tissues and organs that are in direct contact with the prosthesis (E. I. Gavrilov).
Models of the jaws can be classified:
For the purpose:
- Diagnosticheskie to be studied for diagnosis, planning of construction of the future prosthesis;
- control that are inherently diagnostic as record the condition of the oral cavity before, during and after treatment. They are called standard models;
- working, used for production of dental prostheses, devices;
- auxiliary model of dentition of the opposite jaw prosthetic.
As a rule, to obtain models of the jaws using different varieties of gypsum.
Under the terms of the receipt:
- the monolith (monolith), created through the use of one portion of the same material prosthodontist-a dentist or his assistant in the treatment room (e.g. in the case of using alginate impression material, quick-shrink) or a dental technician in gipsovke room dental laboratory.Non-separable model can be obtained by successive use of two portions of different gypsum types.Thus for the working of the model serves a portion of the gypsum class IV, which fills the imprint of the dentition. After crystallization of this portion of plaster in the usual way, knead the plaster class III and draw up the base model of the jaw. Such a model is called non-separable combination. The name of the model was due to a combination of materials. The creation of the combined model in this way is the basis of obtaining demountable gypsum model of the jaw using pins and a plaster base.
By appointment it can be both diagnostic and working models. At the same time to control hardening of plaster models, the latter (after a preliminary drying to remove the remaining in the pores moisture) is dipped in melted stearin or paraffin. The surface becomes shiny and kind of ivory. Similar processing is used for the preparation of educational exhibits (dummy) in order to make plaster models more imposing and increasing strength and durability;
- portable created by a dental technician in the laboratory. By appointment it is always working models of jaws;
- refractory created by a dental technician of refractories after the duplication of plaster models of jaws in the special cell. By appointment it is always working models of the jaws, intended for casting metal alloys on them.