Prosthetics I. Completed material with feedback Rehabilitation of the masticatory apparatus Damaged teeth – reconstruction of the crown Missing teeth - appropriate prothesis (denture) Prothesis • Individually made, situation in patients is different. • Differences in the type of defect, extent and location in the size, shape and position of teeth in the quality of hard and soft tissues of the oral cavity in intermaxillary relations Prothesis (denture) – the goal Rehabilitation of: Function Comfort Aesthetics Fonation Fixed dentures • Cemented on the teeth – crowns, bridges, inlays Inlay – reconstruction of a part of damaged tooth Crown – reconstruction of anatomic form of the whole tooth Bridge- replacement of missing tooth/teeth Removable dentures • Partial • Complete (full) Procedures In dental surgery In dental laboratory Special instruments Basic (main) materials (metal alloys, ceramics,polymers) Auxilliary (accessory) materials (impression, carving, die, insulating investing, grinding, polishing) Manufacturing of dentures Model of gypsum (plaster) – model of a denture (wax pattern). Model of a denture (wax pattern) directly in the mouth – rarely. Denture is formed without a wax pattern in the dental lab. Manufacturing of dentures Model of gypsum (plaster) – model of a denture (wax pattern) – fabrication of denture. Operations in dental office and in dental lab. Impressions of the jaw - negativ The impression is filled with a casting material (gypsum) – poured into Model (various purpose) Models Working model – the denture is produced on this model (special procedures) Opposing model (antagonal) - necessary for the recognition of intermaxillary relationship Bite regitration - wax Manufactoring of dentures The denture (not the denture itself but the model of the denture) is produced on the working model. The model of the denture is made of the carving wax. The wax is replaced by the main (base) material. Fabrication of dentures The model (wax) of the denture is invested The wax is removed from the form and the base material is placed into the form. Wax removal: The wax is burned out (for metal alloys) or removed by hot water (for polymers – acrylic part of dentures) Impression material Tooth Impression Gypsum (poured into the impression) Impression Plaster (Gypsum) This is a model The wax pattern The model The wax pattern This The investing material The form The melted alloy The investing material The crown The melted alloy The investing material The metal crown Plaster Manufacturing of dentures The method described above = indirect Method (impression, model, pattern, denture) Manufacturing of dentures Direct method (Without impression, the pattern is formed directly in mouth, the fabrication takes place in a dental lab) Manufacturing of dentures Direct method No impression The model of the denture is made directly in the mouth For inlays only Planning of the denture Complex examination 1. Extent and location of the defect 2. Damage of the involved teeth (caries, fillings atc.) 3. Periodontium 4. Shape, size, position of teeth, relationhip to the neighbours 5. Occlusion, articulation – relationship to the antagonists 6. Quality of the alveolar process 7. The level of oral hygiene 8. X-ray examination 9. Study impressioons – study models 10. Detail evaluation of the abutment teeth (pilots) – most impoprtant teeth –canines, premolars Classification of defects of dentition acc.to Voldřich I. Class One or more teeth are missing Small gaps – 1 – 2 teeth Big gaps 3 – 4 teeth at most. This big gaps must be demarcated by pilot of the best quality. (canine, 1st or second molars – pilots of 1st class or their equivalents) Classification of defects of dentition acc.to Voldřich II. Class Reduced dental arch, thenlast tooth is the second molar. With gaps Without gaps Bilateral Unilateral Classification of defects of dentition acc.to Voldřich III. Class Individual teeth or small groups of teeth Classification of defects of dentition acc.to Voldřich IV. Class Edentulous dental arch Classification of dentures Class I. Dentures with dental transfer of masticatory Forces Class II. Dentures with combined transfer of masticatory forces Classification of dentures Class III. Dentures with gingival (mucosal) transfer of masticatory forces, sometimes the transfer can be combined. Class IV. – gingival (mucosal) transfer of masticatory forces. Classification of the pilots (abutment teeth) I. Class pilots Canines Molars (1st, 2nd) Sometimes 3rd molars with excellent biological factor Classification of pilots (abutment teeth) II. nd class pilots Incisors - maxillary incisors, premolars All pilots of class I.with worse biological factor Classification of pilots (abutment teeth) Pilots III. class Mandibulary incisors, third molars, all teeth with bad biological factor Biological factor Comprehension of properties which influences the quality of teeth. Biological factor Caries Pulp vitality Level of the endodontic treatment Level of the resorption of the alveolar bone Periodontium Relationship to antagonists Relationship to neihgbour teeth Way of the transfer of masticatory forces Tooth (fixed dentures, removable dentures class I.) Tooth and oral mucosa (removable dentures class II, or some cases removable dentures class III.) Oral mucosa ( most class III. removable dentures, complete denture) Control questions What are the goals of the prosthetic treatment? What is a biological factors? What class acc. to Voldřich is a dentition with gaps? Control questions What class acc. to Voldřich is a reduced dental arch? What defects are the class III? Which way of the transfer of masticatory forces is in comlpete dentures? Control questions Describe pilots I., II. III. Class What is the biological factor? Describe the principle of indirect fabrication of denture (and direct fabrication). Control questions What is the method of lost wax? What should be taken in account during the planning of the prosthetic treatment?