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Topicality: nowadays a great number of dental self-cured and light-cured composite materials are used for filling carious lesions in deciduous and permanent teeth in children. For good results it is necessary to know its mixing technique, special features of filling cavities of different classes and recommended indications.
Objective: to master the filling technique of class II, III, IV cavities in deciduous and permanent teeth with composite materials; to master the restoration of contact area and proximal contact and tooth’s natural shape.
Tasks:
1. Write down special features of filling class II cavities with composite materials in deciduous and permanent teeth.
2. Write down special features of filling class III cavities with composite materials in deciduous and permanent teeth.
3. Write down special features of filling class IV cavities with composite materials in deciduous and permanent teeth.
4. Sketch additional devices for the restoration of proximal contact.
Educational information:
Direct restoration with self-cured composite materials:
1. Cleaning. Clean the tooth and adjacent teeth with rubber cup, rotary brush and pumice or a prophy paste and water.
2. Shade selection (if available).
3. Cavity preparation.
4. Tooth isolation from saliva.
5. Wash with water spray and air-dry.
6. Pulp protection.
7. Enamel etching. Etch the enamel for 15-20 sec. Wash thoroughly with water spray (45-60 sec.). Air-dry. Etched enamel looses its natural shine and looks matte white.
8. Bonding treatment. Bonding system is applied with a brush over the etched enamel and pulp protective layering as a thin film.
9. Placement of composite into the cavity as a single portion.
10. Finishing and polishing (after material is completely set). Finish and polish using diamond burs, polishing points and discs. To obtain a high gloss, polishing pastes can be used. Contact surfaces are polished with stripes, that can be metal, plastic or textile.
11. Fluoridation of the enamel surface, adjacent to the filling. Fluoride gel and liquid are used to remineralize the enamel.
Direct restoration with light cured composite materials:
1. Cleaning. Clean the tooth and adjacent teeth with rubber cup, rotary brush and pumice or a prophy paste and water.
2. Shade selection. Shade is usually selected by referring to the "Vita" shade guide. Tooth surface and the shade guide must be wet, natural sunlight is preferred.
3. Cavity preparation.
4. Enamel and dentine etching. Etching time is 30 sec., 15 of which are the dentine etching time. Gel etchant is first placed on the enamel. After 15 sec. it is also applied to dentine. If the self-etching adhesive is used, this step is omitted.
5. Etching gel is rinsed off with water for 45-60 sec. Water spray must not be too strong.
6. Air-dry the cavity. Be careful not to damage the etched dentine surface, do not over dry it. Blow the air unperpendicularly to the enamel surface.
7. Bonding treatment.
8. Placement of composite. Filling material is placed into the cavity with carvers and burnishers, preferably with Teflon or titan coating. Every layer of a composite must not be thicker than 1,5-2 mm. Layering technique of composite placement allows the maximal polymerization and reduction of shrinkage. When light-curing a composite, direct the light through enamel of previous layers of composite, if possible, in order to bond composite to the enamel or to the adjacent layers. Second light-curing is done perpendicularly to the composite’s surface. Remember, shrinkage is directed to the source of light.
Modern composites do not require directed polymerization technique, because they demonstrate minimal shrinkage.
9. Finishing and polishing of a composite filling is done in order to create the final shape and natural-looking gloss. Diamond finishing burs, carborund finishing burs are used. Stripes and flosses are used for contact surfaces. The last step is polishing, that is done with special polishing heads of different shapes and polishing pastes.
10. Fluoridation of the enamel surface, adjacent to the filling.
Special features of filling class II cavities:
When filling class II cavities it is necessary to restore the contact area and proximal contact. The missing wall is created with different matrixes. They are placed between the teeth and fixed with matrix-holders, cotton rolls, wedges, special rings. Matrix must tightly hug the tooth and contact the proximal wall of the adjacent tooth. During treatment matrix stretches a little and contacts the adjacent tooth tighter. That allows restoring the proximal contact. To ensure the restoration of a proximal contact wedging is done. Wedges are squeezed into the bottom space between two teeth or a separator is placed between the teeth. Wedges also keep the matrix in place. When light-cured composite is used it is recommended to use the light guiding wedges made of transparent plastic, that allow the light to get into the gingival embrasure. After formation and polishing of the contact area, wedges are taken out. If proximal contact is created properly, matrix band fixates between the teeth (because of teeth coming together) and can be removed with some power applied.
Proper filling of gingival part of the cavity is very important. After the first portion of self-cured composite was introduced, it is carefully condensed to the gingival wall. Continue filling the cavity. Lightly overfill it. Form the occlusal surface just like in Class I cavities.
When light-cured composites are used, sandwich-technique is used to improve the bond strength between the filling and the gingival wall of the cavity. The filling is made of two types of materials.
Special features of filling class III, IV cavities:
The same principles are used for filling class III, IV cavities as for class II cavities. To create the contact area and proximal contact it is important to wedge the teeth. Parapalpal points are recommended for the permanent teeth with the completely formed root to create additional retention points for filling material in class IV cavities. Use a bur of suitable diameter or a special reamer to drill the hole in dentine long enough for the placement of a point that is parallel to the walls of the tooth cavity. Place some glass ionomer or zink-phosphate cement into the hole, and the parapulpal point is screwed in with a special tool. The outer part of the point is cut on the desired level depending on the size of the cavity. Depending on clinical situation, size and shape of the cavity it is possible to fix 2 to 3 parapulpal points. After placing the point the cavity is filled with a filling material. When filling class II, III, IV cavities retraction cord is used in order to prevent the cavity from being contaminated with gingival liquid or blood.
Control questions:
1. Which of the following should be used for restoration of the contact area when filling class II cavity with self-cured composite?
2. Which of the following should be used for restoration of the contact area when filling class IV cavity with light cured composite?
Techniques of opening the tooth cavity in primary and permanent teeth with unfinished root formation. Modern endodontic instruments: types, indications, choice.
Topicality: efficiency of treatment|treating| of the complicated caries of temporary and permanent|constant| teeth for children is|kids| fully|wholly| related|ties| to quality of the carried out preparation of the pulp cavity, assortment|asmt| of the applied materials|fabric|, knowledge of their properties|virtue| and techniques of work|wrk| with them.
Objective:|occupation| to master the methods of preparation of the pulp cavity of temporary and permanent|constant| teeth with incompletely formed|pilchard| roots. To study|study| endodontic instruments, their|its| classification, purposes|purpose| and techniques of work|wrk|.
Tasks:
1. What is the purpose of the pulp cavity preparation?
2. What are the stages of the pulp cavity preparation?
Educational information:
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