1 / 23

Core build up and Amalgam bonding

Core build up and Amalgam bonding. 12 th October. Learning outcomes. To know the definition of a core build up. To understand the advantages and disadvantages of amalgam as a restorative material To understand the aims of amalgam bonding

vaughan
Télécharger la présentation

Core build up and Amalgam bonding

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Core build up and Amalgam bonding 12th October

  2. Learning outcomes • To know the definition of a core build up. • To understand the advantages and disadvantages of amalgam as a restorative material • To understand the aims of amalgam bonding • To know the clinical stages to perform a bonded amalgam

  3. Core Definition • 'that part of a preparation for an indirect restoration consisting of restorative material'.

  4. Types of Core Materials • Amalgam • Composite • Glass Ionomer • Resin Reinforced Glass Ionomer • Compomer

  5. AMALGAM Advantages • Not especially technique sensitive • Strong in bulk section • Sealed by corrosion products

  6. Disadvantages • Best left to set for 24 hours before tooth preparation • Weak in thin section • Mercury content may be of concern to some patients and dentists • Potential electrolytic action between core and metal crown • Not intrinsically adhesive

  7. How is the amalgam retained as the core?

  8. Retention Form • Resistance Form

  9. How is the amalgam retained as the core? • Mechanical • Retentive grooves and notches • Pin Placement • Adhesion

  10. Amalgam Bonding A technique to bond amalgam to the cavity.

  11. Aims Behind ‘Bonded Amalgams’ • Conserve more tooth structure by reducing the need to remove sound tooth tissue for mechanical retention. • Increased Amalgam retention. • Reduce marginal leakage • Reduce the need for dentine pins. • Potentially reduce sensitivity • Improve fracture resistance • Improved amalgam margins

  12. Materials for Amalgam Bonding • Resin Cements ( Panavia) • Adhesive Bonding Agents -initially designed for composites -OptiBond solo -Amalgambond -Scotchbond multipurpose

  13. OptiBond solo

  14. How do they work? • Etching dentine opens up dentinal tubules enabling adhesive resin to flow into dentine and is retained micromechanically • Adhesive resin adheres to amalgam roughness micromechanically and by 4-META adhesive

  15. Claimed Advantages of Amalgam Bonding Techniques • Decreased microleakage • YES • Increased amalgam retention • YES, if cavity lacks mechanical retention • Avoids risk of using pins • YES, 20% of pins perforate, 80oC rise

  16. Claimed Advantages of Amalgam Bonding Techniques • Improved amalgam margins • Depends on adhesive used. Panavia weakens amalgam at margins • Technique may reduce incidence of ditching • Tooth reinforcement • YES, if large cavity • NO, if small cavity

  17. Clinical Indications • Not recommended for routine amalgam cavities with sufficient mechanical retention and undercuts. No evidence of increased benefit to balance increased costs. • Useful for large multisurface amalgams to avoid use of pins • Useful for amalgam repairs • Some easier to use than others

  18. Bonding Agents • Technique • Place matrix band ( lightly vaselined) • Etch 10% phosphoric acid • Wash and dry • Apply adhesive ( Kerr Optibond solo) • Blow off excess solvent • Light cure • Pack amalgam

  19. Limitations of Technique • Increased cost of restoration • Technique sensitive? • Not in use long enough to permit adequate evaluation of clinical performance • Adhesion may breakdown over time

  20. Amalgam Bonding Summary • Amalgam is an excellent core build-up material for posterior teeth • Excellent interim restoration for posterior teeth • Adhesives can be used to improve retention in large amalgam restorations and cores • Adhesives and preparation features can often substitute for pin retention for cores

  21. References • R. W. Wassell, E. R. Smart G. St. George. Crowns and other extra-coronal restorations: Cores for teeth with vital pulps. BDJ 2002 May,192(9): 499-509 • Setcos J.C, Staninec M, Wilson N.H.FThe development of resin-bonding for amalgam restorations. BDJ 1999 Apr, Vol186 (7): 328-330 • Staninec M, Setcos Bonded amalgam restorations: current research and clinical procedure.Dent Update. 2003 Oct;30(8):430-4, 436

More Related