Post and core ppt
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The document discusses the post and core restoration process for teeth, outlining its purpose, ideal requirements, classifications, and biomechanical considerations. It emphasizes the importance of preserving tooth structure during preparation and highlights factors affecting post length, design, and the ferrule effect. The conclusion underscores the significance of understanding physical and biomechanical properties for the successful restoration of endodontically treated teeth.
Post and core ppt
- 1. POST AND CORE CONTENTS Introduction Components of restored teeth Purpose of using post Ideal requirements Classification Biomechanical considerations Various posts Factors to be considered Preparation of the canal space Core Investing and casting Evaluation and cementation Conclusion References
- 2. INTRODUCTION • Long-term success- skilled integration • Post endodontic restoration- – prevent fracture& reinfection – Replace missing tooth Components of restored teeth 1.Residual tooth structure 2.Restorative components Post Core Luting agent
- 3. CLASSIFICATION Walton and Torabinejad According to shape Parallel Tapered According to construction Custom made Preformed According to nature of fit Passive Active According to surface configuration Smooth Serrated Threaded POST PURPOSE OF USING POST Retain the core Distribute stresses Strengthen and reinforce AADC, 2009- POST PLACEMENT WEAKENS THE TOOTH IDEAL REQUIREMENTS Maximum protection Maximum retention Easy to place Visible radio graphically Biocompatible Esthetic Not expensive
- 4. Posts can be classified according to how are they made Prefabricated posts Metallic posts Gold alloys High platinum alloys Co-Cr-Mo alloy Stainless steel Titanium alloys Non metallic Carbon fiber Quartz fiber Zirconia posts Glass fiber Plastic posts Custom-cast posts Cast metal Gold alloy Platinum palladium alloy Base metal alloy Co-Cr-Mo alloy Ni-Cr alloy All ceramic custom made post Polyethylene fiber post
- 5. BIOMECHANICAL CONSIDERATONS PARALLEL POST TAPERED POST More retentive Less retentive Less stresses More stresses Less root fracture More root fracture More dentin removal Less dentin removal Normal tooth - functional forces Modulus of posts Higher ?? Similar ?? Stress produced Tapered post > parallel post Active post > passive post Shorter post > longer post
- 6. CUSTOM CAST METAL POST GLASS FIBER POST PRE FABRICATED POST CARBON FIBER POST ALL CERAMIC POST AND CORE ZIRCONIA POST
- 7. FACTORS TO BE CONSIDERED WHILE PLANNING POST AND CORE Conservatio n of tooth structure: Preparation of the canal conservatio n of coronal tissue Retention form Factors affecting Post length Post diameter Conservationist Preservationist proportionist Post taper and design Luting agent Canal shape Position of tooth in the arch Resistance form Stress distribution Rotational resistance 1. Conservation of tooth structure 2. Retention and resistance 3. Ferrule effect 4. Mode of failure 5. Retreivablity MODE OF FAILURE
- 8. • Sorenson et al, j prosth dent: evaluated teeth with and without post core.They decreased success rate. • Eckerbom et al end dent traum: apical periodontitis more common in post core treated teeth.
- 9. FERRULE EFFECT Latin word Definition Types No adequate tooth structure ?? REQUIREMENTS OF FERRULE FUNCTIONS OF FERRULE RETREIVABILITY Ideal – if trearment fails – should be retreivable Metal posts – difficult Removed by – Rotary instruments and solvents Ultrasonics Masserann kit, post removal system and endo extractors
- 10. PREPARATION OF CANAL SPACE AND TOOTH RADIOGRAPH GP REMOVAL CANAL PREPARATION CORONAL TOOTH STRUCTURE REMOVE UNSUPPORTED TOOTH ANTI ROTATIONAL NOTCH FERRULE EFFECT SHARP ANGLES UNDERCUTS FINISH LINE
- 11. CORE Materials Ideal requirements Core fabrication Shaped in resin or wax Make from amalgam, GIC and composite
- 12. a Ease of use Setting time Bonding mechanism Resin composite Amalgam Glass ionomer Resin composite Glass ionomer Amalgam Resin composite Glass ionomer Amalgam Dimensional stability Microleakage Amalgam Glass ionomer Resin composite Amalgam Glass ionomer Resin composite Amalgam Resin composite Glass ionomer CORE MATERIAL Strength
- 13. INVESTING AND CASTING 1.0 to 2.0cc of extra water is added to the investment and a liner is omitted to increase the casting shrinkage (Shillingburg). This results in a slightly smaller post that does not bind in the canal, and it also provides space for the cement. CEMENTATION Lentulo spiral - According to Shillingburg, retention can be increased by as much as 90% if a lentulospiral is used. Retention is greatest when both the dowel and the root are coated Excess cement must escape coronally as the dowel nearly fills the dowel space. Achieve a uniform, bubble free layer - evenly distributes the stress EVALUATION Casting defects do not interfere with seating Marginal fit not as critical as others No adjustments immediately
- 14. CONCLUSION • The number of endodontic procedures has increased steadily in the past decade with highly predictable results. • Therefore, restoration of teeth after endodontic treatment is becoming an integral part of the restorative practice in dentistry. • Proper restoration of endodontically treated teeth begins with a good understanding of their physical and biomechanical properties, anatomy, and a sound knowledge of the endodontic, periodontal, restorative and occlusal principles.
- 15. 1. Stephen Cohen, "Pathways of the Pulp", 10th Edn 2. Ingle 6th Edn 3. Walton Torabinejad, "Principles and Practice of Endodontics", 3rd Edn 4. Grossman's endodontic practice, 13th edn 5. Lloyd PM, Palik JF. The philosophies of dowel diameter preparation: A literature review. J Prosthet Dent 1993;69:32–36. 6. Influence of different post design and composition on stress distribution in maxillary posterior teeth. Finite element analysis. Natercia R Silva, Carolina G Castro, Paulo CF Santos-Filho. Indian journal of dental research 2009 vol 20 7. Burke, FJT, Shaglouf, AG, Combe, EC, Wilson, NHF. Operative Dentistry 2000; 25: 388-394. REFERENCES
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