INTRODUCTION TO FIXED PROSTHESIS

INTRODUCTION TO FIXED PROSTHESIS

1. INTRODUCTION: ” The sealed prosthesis is a therapeutic means whose scope goes from the reconstruction of the single tooth to the restoration of the entirety of the occlusal relationships, satisfying both functional and aesthetic requirements. The replacement of missing teeth by fixed devices provides the patient with well-being and masticatory efficiency and often allows him to have a more flattering image of himself. These prosthetic therapies are also of great help in the relief of joint syndromes and their neuromuscular manifestations”. ” SHILLINGBURG 2nd ^edition ”
2. DEFINITION  : the joint prosthesis or fixed partial prosthesis (irremovable) consists of the restoration or replacement of one or more missing teeth, while taking as supports the natural teeth bordering or close to the edentulous sectors.
3. TERMINOLOGY:
   1. Pillar  : it can be a tooth ( a ), a natural root ( b ) or artificial root ( c ), used as a support for a fixed prosthesis, this pillar can be extreme when it borders the edentulous segment or intermediate when the edentulation is on either side of the pillar.
4. Trimming  : or decortication, it is the preparation of the abutment teeth by the removal of the superficial hard dental tissues (otherwise the entire enamel layer and a layer of dentin by wear) using specific instrumentation.
5. Stump (preparation): This is the result of the preparation of an abutment tooth. In other words, it is the prepared abutment tooth.
6. Anchor  : This is the element of the joint prosthesis that covers the pillar.
   1. A. coronal: when the pillar and a tooth.
7. A. corono-radicular: when the pillar is a root. 
8. Draft: This is the inclination of the walls of a preparation, obtained by giving a cervical divergence to the different walls of the preparation of 6° (α+α≈ 0°- 10°) to facilitate the insertion and removal of the impression and subsequently of the prosthesis.

In diagram 2, an undercut preparation hinders the insertion of the prosthesis.

6. Insertion axis: This is the direction in which a prosthesis is put in place and removed without difficulty.
7. The span  : this is the intermediary of the bridge, more precisely it is the artificial teeth belonging to a fixed plural prosthesis with the exception of the teeth covering the abutment teeth. 
8. Cervical limit of a preparation (LC): This is the line separating the prepared part from the unprepared part of the dental crown, it is located at the cervical level thus marking the end of the preparation, this limit can be presented in several forms depending on the clinical case (simple trace, cone or a shoulder – diagram F – ), as it can be located at several levels in relation to the marginal gingiva (supra (c), juxta (b) or infra-gingival (a))
9. Sealing: final clinical stage in the development of a joint prosthesis, it consists of fixing the finished prosthesis on its preparation using a biological cement, the sealing of the prosthesis is provisional then definitive.

4. GOALS : 
   1. Functional  : improvement of the patient’s masticatory and phonetic potential, and the restoration of the different movements of the joint.
   2. Organic  :
      1. replace missing teeth
      2. conservation of abutment teeth, antagonist teeth, periodontium and fibro-mucosa of edentulous sectors.
      3. Preservation of severely decayed teeth.
   3. Aesthetic  :
      1. restoration of edentulous areas, particularly anterior teeth.
      2. the correction of some malpositions, touching dyschromias of the teeth of the smile.
   4. Psychic .
5. INDICATIONS & CONTRAINDICATIONS:
   1. INDICATIONS: treatment of intercalary teeth, restoration of occlusion, correction of volume, shape and position anomalies, dysplasia or dyschromia. Therapeutic indication such as definitive retainers or cases of dilapidated teeth…  
   2. CONTRAINDICATIONS: 
      1. Local: hygiene as a factor of major importance. 
      2. General: Significant malpositions, aggressive or terminal periodontal lesions, joint pathologies hindering prosthetic treatment.    
      3. Economic: patients who cannot afford the financial burden of fixed prosthetic treatment.
6. CLASSIFICATION OF DIFFERENT TYPES OF ANCHORING: 
   1. SINGLE JOINT PROSTHESIS: 
      1. CORONARY ANCHOR: 
         1. FULL COVERAGE CROWN: (peripheral crown) Full coverage cap indicated on posterior tooth known by its resonance value and its mechanical resistance, it can be: 

• All-metal  : cast crown (CC); metal crown
• Fully with cosmetic product (ceramic or resin): jacket crown.

• The vestibular inlay crown (VIC). A full coverage crown, in which the cosmetic material only covers the vestibular part and which can be made of resin or ceramic to mask the metal for aesthetic reasons.  
•  Metal-ceramic crown (MCC)  : This is a full coverage crown whose cosmetic material covers all the metal of the infrastructure.

2. PARTIAL OVERLAY CROWNS: 

• The Inlay is a cast metal filling mainly in precious alloy, which fits into intra-coronal cavities. It is intended for the obturation of proximo-occlusal cavities or the cervical region of low volume.
• Onlay when the loss of dental tissue substance is mesio-occluso-distal.
• Veneers: thin layer of dental ceramic that covers the vestibular surface.

2. CORONO-RADICULAR ANCHORAGE SUBSTITUTION CROWN: prosthetic restorations which completely replace the crown by resting on the root via a tenon (the tooth being depulped)

•  Davis crown: full crown attached to the dental root by a prefabricated metal post, generally temporary.
•  Richmond Crown: formed of a root tenon cast in its root part and coronally formed of a metal coping comprising a means of supporting the cosmetic material.
• Inlays-core: it is a Richmond or its coronal part is in the form of a false metal stump which will be covered by a CIV, CCM or not a Jacket crown.

2. PLURAL joint prosthesis: BRIDGES or BRIDGES: fixed device that is attached to: stumps, roots or an implant to replace missing teeth. In general, it must have at least two pillars. It includes:
   1.  the support points or pillars
   2. The bridge span: a set of artificial teeth intended to replace missing teeth. Also called bridge intermediates.
3. INTRODUCTION TO FIXED PROSTHESIS
4. THE STAGES OF CREATING A FIXED PROSTHESIS:  

1. Study print.
2. Preparation of the temporary prosthesis 
3. Preparation (cutting) of dental tissues to produce a stump
4. Taking the fingerprint
5. temporary sealing of the temporary prosthesis
6. Processing the prints and obtaining a working model
7. The production of wax models of the armature, the casting and finishing of the armature 
8. Trying on the metal frame
9. Application of cosmetic material
10. Sealing or bonding of the prosthetic part
11. Control.

8. CONCLUSION: Mastering the terminology specific to joint prosthesis is the first step to understanding and successfully performing the prosthesis itself.
9. BIBLIOGRAPHY: 
   1. Fundamental basis of joint prosthesis; 2nd ^edition ; Schilingburg.
   2. Manual of fixed single prosthesis; MASSON; J exbrayat

INTRODUCTION TO FIXED PROSTHESIS

  Sensitive teeth react to hot, cold or sweet.
Sensitive teeth react to hot, cold or sweet.
Ceramic crowns perfectly imitate the appearance of natural teeth.
Regular dental care reduces the risk of serious problems.
Impacted teeth can cause pain and require intervention.
Antiseptic mouthwashes help reduce plaque.
Fractured teeth can be repaired with modern techniques.
A balanced diet promotes healthy teeth and gums.
 

INTRODUCTION TO FIXED PROSTHESIS