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| Preparation step | Instruments used | Anatomy peculiarities of Deciduous teeth | Special features of performing the step in primary teeth | Anatomy peculiarities of permanent teeth with unformed root | Special features of performing the step in permanent teeth with unformed root | Special features of performing the step for filling with glass ionomer cement | Special features of performing the step for filling with composites | |
| Bonding to the enamel (self-cured) | Bonding to the enamel and dentine (light cured) | |||||||
| Cavity opening | Fissure, round, burs in high-speed hand-piece | Low hardness of primary teeth tissues | possible opening from the vestibular surface (esthetics is of secondary importance) | Low hardness of primary teeth tissues | Careful preparation, | Maximal saving of enamel | Possible opening from the vestibular surface, cut the enamel without dentine beneath it | |
| Cavity widening | Fissure, conical burs | Low hardness of primary teeth tissues, thin enamel and dentin layers | Careful preparation, keep in mind the pulp chamber | Low hardness of primary teeth tissues, thin dentin layer | Careful preparation, keep in mind the pulp chamber | Maximal tissue-saving | Save the dentin beneath the enamel | |
| Necrectomy | Excavator, round burs in low-speed hand-piece | Low mineralization of dentin, thin dentin layer, little of no reparative dentine | Careful preparation, use mostly excavator, keep in mind the pulp chamber | Low mineralization of dentin, thin dentin layer, little of no reparative dentine | Careful preparation, keep in mind the pulp chamber | Tissue-saving | Prepare up to the sound dentin | Prepare up to the sound dentin to ensure a quality bonding and cosmetic effect |
| Cavity formation | Neverse-conical, conical, fissure burs | Thin enamel and dentin layers, little of no reparative dentine, thin walls in cervical region | Proximity of the pulp chamber | Low hardness of primary teeth tissues, thin dentin layer, little reparative dentine | keep in mind the pulp chamber | Possible formation without retention points, without additional cavities, tissue-saving preparation | Classical formation with maximal saving of sound enamel | Possible formation without retention points, without additional cavities, cut the enamel with no underlying dentin |
| Preparation of enamel edges | Fissure, conical, fire-like diamond head of finishing bur | Thin enamel layer | Careful preparation with burs | Finishing of the edges without formation of the falc | Falc formation with a great surface | Falc formation |
Control questions:
1. Which cases require formation of the additional cavities on vestibular or oral surface when preparing class III cavities in deciduous and permanent teeth?
2. What are the requirements for the depth and width of additional cavities in preparation of class IV cavities in primary and permanent teeth in children?
3. What are the special peculiarities of class III and IV cavity preparation in deciduous teeth compared to the formed permanent teeth?
4. What are the special peculiarities of class III and IV cavity preparation in permanent teeth with unformed root compared to the formed permanent teeth?
Dental cements and amalgam. Techniques of preparation. Filling techniques of carious cavities of I-V classes by Black in a temporary teeth and permanent teeth with immature root development.
Topicality: duration of clinical effect of filling carious cavities in temporary and permanent teeth at children is based on observance of preparation techniques and use of dental cements and amalgams.
Objective: to study structure, the main physical and chemical properties, indications for use of dental cements and amalgams in temporary and permanent teeth at children. To know techniques of preparation and filling by cements and amalgam carious cavities of the I-st and V-th classes in temporary and permanent teeth with immature root development on phantoms.
Tasks:
1. Classification of dental cements and amalgams.
2. Structure, the basic positive properties, disadvantages and indications for application glass-ionomer cements.
3. Name structure, the basic physical and chemical characteristics and indications for application of amalgam.
Educational information:
Dental cements and amalgam during many years have been used in pediatric dentistry.
Cements (D. S. Smith, 1995):
· Phosphatic – (Zinc-phosphatic, Silico-phosphatic, Silicate)
· Phenol- (Zinc-eugenol, Ca (OH) 2 Salycylatic)
· Polycarboxylate (Zinc- polycarboxylate, Glass-ionomer)
· Acrylic (Polymetacrylic, Dimethylacrilic)
The first three kinds are used mainly in children's dental practice: phosphatic, phenolic and polycarboxylate cements.
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