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Techniques of filling of carious cavities of the II-nd class in temporary and permanent teeth by stomatologic cements and an amalgam. Restoration of contact point.

Topicality: filling of carious cavities of the II-nd class by Black is a challenge because of necessity of restoration of contact point. There is no qualitative restoration without restoring tooth’s correct anatomic form and, first of all, without precisely recreated contact point. Restoration of contact point demands knowledge of sequence of actions, technique and the additional accessories that must be used. Knowledge of formation contact point features during II class carious cavities filling by stomatologic cements and amalgam in a temporary and permanent teeth is necessary for the future dentist.

Objective: to know technics of filling of carious cavities of II class by Black by stomatologic cements and amalgam in temporary and permanent teeth on phantoms. To be able to restore contact point with use of matrix systems and additional accessory.

Tasks:

1. To know peculiarities of preparation of carious cavities of the II-nd class in temporary and permanent teeth.

2. To know peculiarities of preparation of carious cavities under amalgam.

3. To know peculiarities of preparation of carious cavities under various kinds of stomatologic cements.

Educational information: filling of carious cavities of the II-nd class is always associated with restoration of contact point. Contact point is a contact zone of near located teeth. Contact point is plane in a temporary teeth and it is located below equator. In permanent molars and premolars the contact point is dotty and also is located in the field of equator. The contact point carries out the important function of chewing, distribution of chewing loading, protects gum papilla during eating. Correctly formed contact surface of a tooth should have the form close to spherical. The zone of contact between the teeth should be recreated in the field of equator and slightly above as in intact teeth. The reconstruction of contact point demands use of additional accessories, such as matrix, wedges, means for gum retraction. Matrices allow to form correctly contact point, to prevent glou of a saliva, gingival liquids and blood in the prepared cavity, especially at localization of cavities lower than a level of gum. The edge of a matrix should settle down on 0,5 - 1,0 mm below gingival wall formed carious cavity. Such arrangement of matrix allows to avoid formation of hanging edge of a fill. Now there are various types of matrix systems, including matrix holder. Matrices differ as a material they are made (metal, plastic (polyvinylchloride), combined), on a configuration (flat, contour) and to destination (for separating, protective, contouring). Metal matrices that are used during work can be with an amalgam, glass ionomer cements, packed composites and ormocers. They are more thin and firmer, that facilitates their introduction in interproximal interval. Flat metal matrices can be issued as strips by thickness 0,03 - 0,06 mm or in a roll as a metal tape. Contour metal matrices are issued two thickness 35 and 50 microns. Better restorations turn out at use of matrices by thickness 35 microns. Plastic matrices share on matrices for restoration chewing and frontal group of teeth. They differ by the form and the mechanism of fixing on a tooth. Plastic (photoconductive) matrices are used with composit materials. Contour matrices are much closer to the form of a tooth, than flat. The word "contour" means that these matrices are convex, with the curvature close to curvature of the restored tooth (Fig. 1). The matrices are designed for separate groups of teeth, and made according to their anatomic peculiarities, are called section. Section matrices are used at restoration carious cavities of the II-nd class by Black. There are 5 forms of matrices of the various size: small, small with a ledge, big, big with a ledge, average with a ledge. Matrices with a ledge are applied when gingival wall of carious cavity of the II-nd class is located below the level of gum. Installation of matrices is possible as independent, and with use of matrix holder and adjusting accessories.

Matrix systems are used with: 1.Universal matrix holder Tofflemire (Fig. 2).

2. Ivory matrix holder (Fig. 3). 3.Section matrix systems (ЗМ ESPE, Pallodent Dentsply, a spring clamp, " TORAHS ВМ ") (Fig. 4).

Fig. 1 Contour metal matrix

Fig. 2 Universal matrix holder Tofflemire.

Fig. 3 Ivory matrix holder

Fig. 4 The nipper and holding ring ЗМ for section matrices.