MINISTRY of PUBLIC HEALTH of UKRAINE
VINNITSYA NATIONAL MEDICAL UNIVERSITY
by N.I.Pirogov
It is "confirmed"
on a methodical meeting of
department of pediatric dentistry
head-chair
doc. Filimonov Yu.V.
" " in 20
Methodical recommendation for 2d year students
of dental faculty
Educational discipline / Propedeutics of pediatric dentistryModule ¹ / 1
Rich in content module ¹ / 1
Topic / Principles of cavity preparation and nomenclature for 1 and 2 Black class of caries deciduous and permanent teeth at the children. The choice of instruments.
Course / 2
Faculty / Dental
Vinnitsya 2010
1. Actuality of theme: Treatment of caries in deciduous and permanent teeth at children one of the actual problems of a children's odontology. One of the major stages of treatment caries is preparing carious cavities. The mineralization of a teeth lasts 2-3 years after eruption. There are least miniralised fissures and аproximal surfaces. Therefore, as a rule, these areas are amazed with caries.
2. Concrete aims:
1. To master main principles of preparing of carious cavities 1class of permanent and deciduous teeth depending on depth of a lesion and a choice of filling materials.
2. To master main principles of preparing of carious cavities 2 class of permanent and deciduous teeth depending on depth of a lesion and a choice of filling materials.
Names of previous disciplines / Skills are gotNormal anatomy / Able defirintiation temporal and permanent teeth. To know the anatomic features of temporal teeth depending on the stage of development of tooth.
Therapeutic stomatology / To know basic methods and principles of preparing of teeth in grown man age. Oriented in the choice of instruments for realization of that or other manipulation. Able to pick up stopping material depending on a situation.
Orthopaedic stomatology / Oriented in materials which are utillized in the clinic of orthopaedic stomatology.
3. Base knowledges, abilities, habits which are necessary for study the topic.
1. To know the features of anatomy and histology of hard tissues of deciduous teeth at different stages of development.
2. To know the feature of anatomy and a histology of hard tissues of a permanent teeth at different stages of development.
3. To know about caries and main principles of the treatment.
4. To know structural components of a carious cavity.
5. To know classification caries cavities by Black.
6. To know the basic dental instruments and their purpose.
5. To know classification of dental burs.
6. To know stages of preparing carious cavities.
4.1. List of basic terms, parameters, descriptions which a student must learn at preparation to lesson:
4.2. Theoretical questions for lesson:
1. Which general rules of tooth preparation you know?
2. The stages of preparation of carious cavities at 1 class by Black.
3. The stages of preparation of carious cavities at 2 classes by Black.
4. Which rules preparing of walls of carious cavities by Black?
5. Which rules preparing of walls of carious cavities by Lukomsky?
6. Which stages preparing of walls of carious cavities by MIT?
4.3. Practical tasks which are executed on the lesson:
1. To study preparing stages of carious cavities at 1 class of deciduous teeth depending on a stage of development of a tooth and filling materials.
2. To study stages of preparing of carious cavities at 2 class of deciduous teeth depending on a stage of development of a tooth and filling a materials.
3. To study stages of preparing of carious cavities of 1 class of a permanent teeth depending on a stage of development of a tooth and filling materials.
4. To study stages of preparing of carious cavities of 1 class of a permanent teeth depending on a stage of development of a tooth and filling materials.
5. Plan and organizational structure of lesson from discipline.
¹ / Stages / Distributing of time / Types of control / Facilities of education1. / Preparatory stage / 15 min / practical tasks, situatioonal tasks, verbal questioning, are after the standardized lists of questions. / textbooks, manuals, methodical recommendations.
1.11.1 / Oh the Organizational questions.
1.2 / Forming of motivation.
1.3 / Control
initial level of knoweledge .
2. / Basic stage. / 55 min
3. / Final stage / 20 min / tests tasks
3.1. / Control of final level of preparation.
3.2. / General estimation of educational activity of student.
3.3 / Informing of students is about the topic of next lesson.
Content of topic:
Preparing of a carious cavity is a surgical operative treatment which provides tool excision of the tissues of a tooth amazed by caries. Successful cavity preparations for restorative materials such as dental amalgam, composite, resin, or cast metal are designed to allow placement and maintenance of each restorative material and, at the same time, to ensure the preservation of remaining tooth structure. Allocate following stages:
1.Gating and extension cavity.
2. Necrotomia, deleting decay tooth structure.
3. Forming retention and resistance form of preparation.
4. Working with edges op preparation.
Gating and extension cavity. It is used high speed handpiece and usual or miniature diamond round and fissure burs. Round burs input in cavity, then with interrupting moves (from floor to surface) delete hangin enamel. With the help of fissure burs, the walls are making plamb.
Necrotomia, deleting decay tooth structure. For removing soft tissue, we used a sharp excavator. The walls dentine excavate in the axial direction. The deep (parapulpar) dentin excavate horizontally. For removing hard decay tissue to use carbide burs. For best result is recommended to use low speed handpiece.
The principles of cavity preparation are now applied uniquely for each restorative materials and each period of tooth evolution and even the general caries situation.
For prevention of damaging enamel margins, to cut it under the angle (40-45°) to surface of enamel. Use for this finishing diamond burs (finirs) and air turbine handpieces.
The principles of cavity preparation devised and published by dr. Black in 1908 are still appropriate for low-adgesive materials, such as amalgam, phosphate and selico-phosphate cements.
1.Extension for prevention.
Extension for prevention, to include those pits and fissures adjoining the defects with active decay, especially should be considered when the patients is young, has a high caries rate, and /or exhibits poor oralhygiene.
2.Resistance Form
When restorative material is used on stress bearing surface, a minimum depth of 1,5-2mm is recommended due too the briltleness of amalgam (cements) in thinner layers. Ideally, amalgam meets the unprepared tooth surface at right angles to provide resistance form.
3.Retention (Class I)
For amalgam and cements, retention is provided in an occlusal preparation by a slight convergence of the buccal and lingual preparation walls towards the occlusal surface, which, due to the slope of the triangular ridges, is coincidentally accomplished by ending the buccal and lingual cavity walls at right angles to the unprepared triangular ridges.
4.Finiring – All edges prepared with finiring burs for deleting enamel prisms which have lost a bearing.
Also there are other methods preparation of caries cavity:
1. Method “Biological expediency” devised by Lukomskiy. It provides sparing removing caries. Ideally for composit, glass ionomers, but not for amalgam and cements.
2. Method “Prophylactic filling” was designed for glasionomer cements and composits, which have good adgesive and mechanical properties. The main principle of this method is preparing up to immune zones.
3. ART-methods (atraumatic restorative treatment) was proposed by dr.Taco Pilot. The doctor make only necrotomy with the help of the exavater (without using handpies) end next filling the cavity by glass-ionomer cement (Fuji IX). This method is painless and can using in all stages of teeth developments.
Features of preparing cavities depends from period of teeth development.
First stage - development (formating) of roots. At this stage the pulp chamber is big. That is why sparing preparation is needed. Use method of Prophylactic filling.
Second stage – the generated roots. It is recommended the Black method of preparation.
Third stage – resorbtion of roots.You can use Lucomskiy’ method.
Features of preparing cavities depends from anatomic srtucture. There are typical localization at the picture 1.
The vartiants preparing of enamel edges depends from filling materials are shown at the picture 2.
Pic. 2
1-damadged prism
2- chip of the prism
3- ceramic, amalgam
4- cement
5- inlay
6- composit
Class II Caries. Principles of cavity preparation and terminology.
The preparation for a class II carious lesion can be restored with amalgam, direct composite, inlays, or onlays (cast metal or tooth-colored). The larger the preparation (and, therefore, the thinner the remainng tooth structure), the more appropriate a cast metal onlay might be to protect the remaining thin tooth and provide adequate resistance form. Recent improvements in composit restorative materials and techniques have resulted in increased use of this tooth colored material foc Class II sestorations, especially when esthetics is an important factor.
a. Extension for prevention (Clas II)
To reach Class II lesions, the dentist must, in most cases, prepare a proximal box that extends apically through the marginal ridge in order to reach the decay which forms just cervical to the proximal contact. The Class II preparation often extends over some of the occlusal surface to include adjacent occlusal pits and fissures as in Class I preparation, whereas the proximal box might be compared to a stair-step descending gingivally off of the occlusal portion. The Class I portions follows the principles for restoring a Class I lesion already discussed, but the proximal extension (box) adds new features. For example, the buccal and lingualn walls of the proximal box of Class II preparations are extended beyond the proximal contact areas just into the buccal and lingual embrasures. In this way, the margins of the restorations can be better evaluated by the dentist and kept clean by the patient.
Retention Form (Class II)
For Class II amalgam cavity preparations, the buccal and lingual walls of the occlusal portion and the proximal boxes are prepared so that are prepared so that they converge slightly towards the occlusal to prevent the restoration from dislodging occlusally as in the Class I preparation. Retentive grooves may be prepared buccally and lingually in a proximal box as extensions of the internal vertical wall of the box that is aligned along the long axis of the tooth, and is therefore called the axial wall. These retentive grooves are designed to prevent the amalgam restoration from dislodging in a proximal direction. They are located at the axiobccal and axiolingval line angles seen later in figure. For cast metal inlays, opposing buccal and lingual walls must diverge slightly towards the occlusal. The two axial walls in a mesio-occlusodistal inlay preparation must converge slightly towards the occlusal, so that an accurate wax model (pattern) and subsequent casting can bee seated within the preparation and than removed while constructing and relining the casting prior to cementation. Bevels are angular enamel reduction placed at the cavosurface in order for the margin (or outer edge) of the casting to be thin enough so the dentist an perfect the adaptation and minimize the cavosurface gap between tooth and metal. The goal is to minimize the gap between the casting and tooth since this gap is to be filled with dental cement which is not as strong or as durable as the metal.
Materials are for self-control:
1. GENERAL RULES OF TOOTH PREPARATION:
1. Pain control, Opening and widening the caries cavity, Necrectomy, Forming and shaping the cavity, Beveled enamel margins.
2. Opening and widening the caries cavity, Necrectomy, Forming and shaping the cavity, Beveled enamel margins.
3. Pain control, Opening and widening the caries cavity, Necrectomy, Forming and shaping the cavity.
4. Pain control, Opening and widening the caries cavity, Forming and shaping the cavity, Beveled enamel margins.
5. Pain control, Necrectomy, Forming and shaping the cavity, Beveled enamel margins.
2. Classification of tooth preparations by G.V.Black :
1. is designated as Class I, Class II, Class III, Class IV, and Class V;
2. is designated as Class I, Class II, Class III, Class IV;
3. is designated as Class I, Class II, Class III;
4. is designated as Class I, Class II, Class III, Class IV, V,VI.
3. Class I Restorations:
1) All pit-and-fissure restorations are Class I, and they are assigned to three groups, as follows: Restorations on Occlusal Surface of Premolars and Molars;Restorations on Occlusal Two Thirds of the Facial and Lingual Surfaces of Molars;Restorations on Lingual Surface of Maxillary Incisors.
2) All pit-and-fissure restorations are Class I, and they are assigned to too groups, as follows: Restorations on Occlusal Surface of Premolars and Molars;Restorations on Occlusal Two Thirds of the Facial.
3) All pit-and-fissure restorations are Class I, and they are assigned to too groups, as follows: Restorations on Occlusal Surface of Premolars and Molars Restorations on Lingual Surface of Maxillary Incisors.
4) All pit-and-fissure restorations are Class I, and they are assigned to too groups, as follows: Restorations on Occlusal Surface of Premolars and Molars; Restorations on Lingual Surface of Maxillary Incisors.
Literature.
Basic:
1.Lectures which are read on the department of pediatric dentistry.
2. Л. О. Хоменко, О. І. Остапко, О. Ф. Конанович, та ін. Терапевтична стоматологія дитячого віку.- Видавництво "Книга плюс", 2007 р.
3. Pediatric dentistry /Ed. R.R.Welbury.- Oxford, 1997 – 584p.
Additional:
1. Боровський Г.В., Барішева Ю.Д., Максимов К. М. и др. Терапевтическая стоматология. — М.: Медицина, 1997.
2. Pinkham J.R. Pediatric dentistry. – 2nded.- W.B. Sounders Company. – 1994.- 647 p.