30 Fixed Prosthodontics

2 Specialty that deals with replacement of missing teeth or parts of teeth with extensive restorations

3 Purpose Restores masticatory function Improves aesthetics and often self- esteem Improves speech Promotes good oral hygiene Prevents further movement of teeth because of support of prostheses

4 Advantages of a Fixed Prosthesis Aesthetic Secure in mouth Restores function for many years

5 Patient Considerations Complete medical and dental history Examination of the intra- and extraoral tissues Radiographs Impressions for study models (diagnostic casts)

6 Patient Considerations Intraoral photographs taken with intraoral camera Extraoral photographs

7 Candidates for Fixed Prostheses Must have motivation to maintain prostheses Must have healthy supportive tissues

8 Case Presentation Provide treatment choices to patient Review costs and insurance coverage Discuss number of appointments required

9 Types of Fixed Prostheses Indirect restoration –Fabricated in dental laboratory –Examples include: Crowns and bridges Veneers Inlays and onlays

10 Types of Fixed Prostheses Direct restoration –Restoration placed directly on tooth at appointment –Examples include Direct resin veneers

11 Indirect Restorations Impressions taken and sent to lab Temporary restoration is fabricated and placed Fixed prostheses fabricated in lab Restoration cemented in mouth at second appointment

12 Crowns Anatomically shaped and fitted to tooth Covers teeth with extensive decay or breakdown Placed when there is no longer enough tooth structure to retain a filling

13 Types of Fixed Crowns Full-cast crown –Covers entire coronal surface of tooth Partial crown –Cast restoration that covers three or more surfaces of a tooth –Facial surface is left intact

14 Porcelain Fused to Metal (PFM) Full porcelain crown Porcelain fused to metal crown

15 Three-Quarter Gold Crown

16 Inlays and Onlays: Cast Restorations Inlays –Restoration placed within tooth –Covers area between cusps in middle of tooth and proximal surfaces involved Onlays –Include cusp ridges of tooth

17 Inlays and Onlays Gold onlay restoration on mandibular first molar Gold inlay restoration

18 Bridges Restoration that spans the space of one or more missing teeth Requires coverage of one or more adjacent teeth

19 Components of a Bridge Abutments –Teeth on either side of a missing tooth that provide support to which the fabricated tooth (pontic) can attach Pontic –Portion of bridge that replaces missing tooth

20 Bridges and Abutments ( A) Three unit bridge abutments, points, and retainers Missing tooth Tissue Abutments (prepared teeth) Fixed bridge Retainers Pontic Porcelain-fused-to-metal bridge (A)

21 Bridges and Abutments (B) Maryland bridge (B)

22 Veneers Types –Direct resin veneers –Indirect resin veneers –Porcelain veneers Advantages –Natural in appearance –Requires minimal tooth reduction

23 Types of Materials Used for Fixed Prosthetics Alginate impression material Bite registration materials Retraction cord Final impression material Temporary cement Bonding agent Permanent cement

24 Types of Materials Used for Fixed Prostheses Gold casting alloys –Gold used in crowns, inlays, and onlays is not pure gold Combination of metals known as an alloy Platinum, palladium, tin, and iron

25 Tooth-Colored Cast Restorations Porcelain –Used for inlays and bonded veneers –Porcelain fused to metal crowns and bridges –Porcelain crowns

26 Tooth-Colored Cast Restorations Composite resin –Used for inlays, onlays, and veneers –Stronger than direct composite restorations –Bonded in place

27 Cad/Cam Restorative Systems Becoming more common Allows metal-free, tooth-colored restorations to be fabricated in one appointment Inlays, onlays, crowns, and veneers

28 Cad/Cam Restorative Systems No unpleasant impressions No need for temporaries Less reduction of healthy tooth structure

29 CEREC (Chairside Economical Restorations of Aesthetic Ceramics) Switzerland — 1980 Several factors to consider –Time investment to train staff –Large financial investment –Computer familiarity

30 Basic Steps of CEREC Restoration Patient is seated and anesthetized Ceramic shade is selected Ceramic tooth prepared Prep coated with reflective powder Camera prepared optical impression Restoration designed from CEREC data

31 Basic Steps of CEREC Restoration Milling machine mills restoration Restoration tried in position and adjusted Restoration bonded in place Polishing

32 Role of the Laboratory Technician Fabricates custom trays Pours impressions Articulates models (casts) Prepares wax patterns

33 Role of the Laboratory Technician Invests and casts gold alloy restorations Prepares porcelain and PFM crowns Fabricates prosthesis according to dentist’s request

34 Role of the Dental Assistant Provide patient education Prepare treatment room Take preoperative X-ray Make preliminary impressions and bite registration Select shade

35 Role of the Dental Assistant Assist at chairside Place and remove temporary crowns Remove cement Pour impressions Fabricate custom trays

36 Fabrication of the Prosthesis in the Dental Laboratory Pouring alginate impression of the opposing arch in plaster Pouring final impression to make a master mold and die Creating a wax pattern on the die Investing and preparing wax pattern for casting

37 Fabrication of the Prosthesis in the Dental Laboratory Casting the die once invested material and metal are heated Casting the crown in gold alloy Painting porcelain on the crown and curing Finishing and polishing

38 Crown Preparation Appointment Administer anesthetic Make preliminary impressions and bite registration Remove decay Using a diamond bur, reduce tooth structure

39 Crown Preparation Appointment Place retraction cord Take master impression Fabricate temporary crown Reschedule patient for delivery of crown

40 Crown Preparation Tray

41 Shade Selection

42 Materials Used to Take the Bite Registration

43 Types of Preparations Examples of cavity margin on preparation-chamfer, shoulder, and shoulder with beveled edge Pins placed in a prepared tooth for support and retention

44 Types of Preparations Chamfer preparation Shoulder preparation Beveled shoulder preparation Preparation at gingiva margin Crown Prepared tooth

45 Gingival Retraction Techniques Placing retraction cord around the prepared tooth

46 Master Impression Dental assistant receives syringe with light-bodied impression material and transfers tray with medium- to heavy- bodied impression material to dentist Final impression

47 Master Impression

48 Try-in Appointment Remove temporary crown Remove excess cement Try-in crown Adjust contacts and occlusion if needed

49 Try-in Appointment Line inside of crown with cement Place crown on tooth and have patient close on bite stick Remove excess cement from margins

50 Retention Techniques Required when there has been extensive tooth loss due to the following: –Decay –Fractures –Broken tooth structure

51 Retention Techniques Core buildups –Provide retention for crown –Performed on vital teeth Retention pins –Used to enhance core buildup –Available in kits with various sizes and tools

52 Pin Placement

53 Core Post Placement A core post in place in a nonvital tooth Crown Core buildup Apical seal of root canal

54 Tooth with Core Post, Core Buildup, and Pins Core buildup Core post Crown Pins Natural tooth structure

55 Vital Tooth Pins inserted into enamel Buildup material then surrounds pins Examples of materials used: –Amalgam –Composite –Silver alloy/glass ionomer

56 Nonvital Tooth Portion of gutta percha is removed for coronal pulp region Post cemented into canal Core buildup material placed around post Buildup prepped for crown Master impressions are taken

57 Implant Retainer Prosthesis Can be placed after six months Attach to post or screw May be a crown or part of a bridge

58 Maintenance of Fixed Prosthodontics Part of patient’s daily routine Aids can be used to clean bridgework Should be removed routinely and thoroughly cleaned

59 Advanced Chairside Functions Gingival retraction –Ensures an impression with clear margins –Retracts tissue horizontally to allow room for impression material –Displaces tissue vertically to completely expose margin

60 Types of Gingival Retraction Mechanical –Placed in sulcus of healthy gingiva –No drugs or chemicals used –Left in place for minutes

61 Types of Gingival Retraction Retraction Systems –Silicone placed to displace tissue –Prevents bleeding and creepage

62 Types of Gingival Retraction Chemical retraction –Impregnated cord is used –Topical solution is used –Know the contraindications

63 Types of Gingival Retraction Surgical retraction –Dentist removes tissue with surgical knife –Electrosurgery unit may also be used