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New microsoft office power point presentation / orthodontic seminars

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Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.

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  • 1. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • 2. Posterior partial veneer crown Inlays onlays Resin bonded retainer Radicular retainers Failures in retainers Conclusion references www.indiandentalacademy.com
  • 3. www.indiandentalacademy.com
  • 4. STEPS 1. Occlusal reduction 2. axial reduction 3. Proximal groove placement 4. Occlusal offset 5. Bucco-occlusal contra bevel 6. Finishing of preparation www.indiandentalacademy.com
  • 5. Depth orientation grooves Functional cusp bevel www.indiandentalacademy.com
  • 6. Lingual axial reduction : torpedo diamond Proximal axial reduction : torpedo diamond www.indiandentalacademy.com
  • 7.  Use tapered carbide bur  Placed parallel to long axis of the tooth  Grooves are 4mm long and terminate 0.5mm of gingival finish line www.indiandentalacademy.com
  • 8. Proximal groove Proximal flare Proximal flare www.indiandentalacademy.com
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  • 13.  Similar in preparation with maxillary  Only difference is the preparation of occlusal shoulder on the facial surface, gingival to occlusal contacts which is 1mm wide www.indiandentalacademy.com
  • 14.  This method of preparation is known as hooding , increases retention and resistance to displacement  Occlusal shoulder on buccal aspect of buccal cusp serves the same purpose as the offset on maxillary preparation Completed mandibular3/4 crown preparation www.indiandentalacademy.com
  • 15. www.indiandentalacademy.com
  • 16. ¾ crown with proximal box www.indiandentalacademy.com
  • 17.  In this preparation lingual surface is left intact and buccal surface is involved  Used on mandibular molars to preserve intact lingual surface and on fixed partial denture abutments with severe lingual inclinations www.indiandentalacademy.com
  • 18.  This preparation closely resembles a maxillary ¾ crown as the axial surface of the non functional cusp is uncovered  Grooves are placed at linguoproximal line angles and joined by occlusal offset on the buccal slope of lingual cusps www.indiandentalacademy.com
  • 19.  A three-quarter crown that is rotated 90degrees,with the distal rather than buccal surface left intact  Used as a retainer on tilted mandibular molar fixed partial denture abutment www.indiandentalacademy.com
  • 20. Indicated in patients  Low incidence of inter proximal caries  Good oral hygiene  Caries free distal surfaces www.indiandentalacademy.com
  • 21. Preparation  Mesial surface parallels the path of insertion of mesial abutment prepartion  Clearance of 1.5mm is obtained from occlusal reduction which terminates at the distal marginal ridge www.indiandentalacademy.com
  • 22.  Grooves are placed on buccal and lingual axial surfaces parallel to each other www.indiandentalacademy.com
  • 23.  Occlusal offset is prepared connecting buccal and lingual grooves to strengthen the disto- occlusal margin www.indiandentalacademy.com
  • 24. www.indiandentalacademy.com
  • 25.  Includes, the surfaces covered by three- quarter crown and in addition the distal half of buccal surface  Therefore, mesial aspect resembles three quarter crown and distal aspect a complete crown  Mesial half of buccal tooth surface remains intact  Preparation is similar to three quarter crown, differs only in placement of groove www.indiandentalacademy.com
  • 26.  Prepare mesial groove similar to three quarter crown  Place the buccal groove parallel to the mesial groove and perpendicular to bucco- axial wall  Buccal groove should resist mesio- distal displacement of a probe  A contra bevel is given on mesio- buccal cusp which connects the mesial flare with buccal groove www.indiandentalacademy.com
  • 27.  Mesial wall of buccal groove is smooth and has 90 degree cavo-surface angle, leaving no unsupported enamel  Adequate clearance must be established interproximally upon completion of preparation Adequate clearance interproximally www.indiandentalacademy.com
  • 28. www.indiandentalacademy.com
  • 29.  INLAY is an intracoronal restoration, which is used for medium sized single tooth proximo- occlusal and gingival lesions  ONLAY is an intracoronal restoration, which is used to restore a more extensively damaged posterior tooth with a wide mesio- occluso-distal lesion inlay onlay www.indiandentalacademy.com
  • 30.  A cavity which does not exceed 1/3 of the intercuspal distance  Teeth have minimal occlusal facets or no occlusal facets, if present limited only the occlusal surface.  Tooth which is not an abutment for long fixed partial denture.  in premolars and molars with minimal caries that need mesio occlusal or disco occlusal lesion www.indiandentalacademy.com
  • 31. ◦ contraindicated unless there is sufficient bulk to provide the resistance and retention form, as they rely on intracoronal wedging retention Advantages • Long lived restoration,because of excellent mechanical properties of material used • Resistant to corrosion • Esthetically acceptable,because of less metal visibility www.indiandentalacademy.com
  • 32.  Inlay is not conservative restoration compared to amalgam restoration, because additional tooth removal in necessary  High occlusal forces may lead to the fracture of the cusp because of wedging effect  Additional preparation may be necessary which may lead to display of metal   www.indiandentalacademy.com
  • 33. Occlusal outline  No. 170Lbur  Place the bur in the central groove and extend the preparation 1mm short of the marginal ridge with appx 1.5mm deep  Completed outline form should have flat pulpal floor to obtain maximum resistance perpendicular to path of insertion www.indiandentalacademy.com
  • 34. Proximal box preparation  Marginal ridge is undermined with no.169L bur  Begin proximal box by running no.169Lbur inside the cemento- enamel junction interproximally to full gingival length  Gingival extension should not be too conservative as box length is important for inlay retention www.indiandentalacademy.com
  • 35.  Undermine tooth structure is removed with enamel hatchet or 169L bur  Extend the box facially and lingually to a point where the contact is broken with adjacent teeth  Final extension is achieved by placing facial and lingual flares www.indiandentalacademy.com
  • 36.  Widen the isthmus where it joins with proximal box  Use enamel hatchet to round the facial and lingual line angles www.indiandentalacademy.com
  • 37. Gingivo axial groove placement  A v shaped groove is placed at the junction of axial wall and gingival floor of the box with gingival marginal trimmer  Sometimes referred as “Minnesota ditch”  To enhance resistance to displacement by occlusal forces www.indiandentalacademy.com
  • 38. Proximal flare  Use flame diamond  Flares are flat planes added to buccal and lingual walls of the box  Provides acute angle for metal to meet finish line on preparation www.indiandentalacademy.com
  • 39.  Place the flame diamond in proximal box and use the tip to cut cavosurface angle of the box from gingival floor up  Diamond should be cutting only when it moves towards occlusal end www.indiandentalacademy.com
  • 40.  Flame diamond is carried across gingivo cavo surface angle of the box, forming gingival bevel on the box that is a smooth continuation of buccal and lingual flares www.indiandentalacademy.com
  • 41.  Occlusal bevel is placed around entire periphery of occlusal portion to produce a smooth finish line Occlusal bevel www.indiandentalacademy.com
  • 42.  Bevel and flare finishing with flame bur Completed preparationFinishing: flame bur www.indiandentalacademy.com
  • 43. www.indiandentalacademy.com
  • 44. Class 1 inlay  Used to restore moderate sized occlusal lesion www.indiandentalacademy.com
  • 45. Class 3 inlay  Contraindicated for incisor due to metal display  Restoration for distal surface of canines www.indiandentalacademy.com
  • 46. Class 5 inlays  Used to restore severe abrasion or erosion and large caries on gingivo facial aspect of molars www.indiandentalacademy.com
  • 47. Indicated for  Broken teeth with intact buccal and lingual cusps  Mod restorations with wide isthmus  Endodontically treated posterior teeth with sound buccal and lingual tooth structure www.indiandentalacademy.com
  • 48.  Occlusal reduction Functional cusp bevelOcclusal reduction www.indiandentalacademy.com
  • 49. Occlusal shoulder placement  Use no.171Lbur  Two acceptable finish lines for mod onlay-shoulder with bevel and heavy chamfer  Cut occlusal shoulder of 1mm width following the termination line of function cusp bevel  Provide space for bulk of metal to reinforce occlusal margin on functional cusp www.indiandentalacademy.com
  • 50.  Isthmus is prepared with no.171L bur  1mm shallower than isthmus on an inlay as occlusal reduction is done www.indiandentalacademy.com
  • 51.  Proximal boxes prepared similar to inlay with flares and bevels at gingival , facial and lingual walls  Only difference is placement of occlusal finishing bevel of 0.5mm width on facial cusp perpendicular to long axis of tooth www.indiandentalacademy.com
  • 52. Preparation on mandibular differs in  Functional cusp bevel and occlusal shoulder on buccal cusp  Lingual bevel is wider and is a definite contra bevel as esthetics is not a consideration on lingual cusp www.indiandentalacademy.com
  • 53. www.indiandentalacademy.com
  • 54.  Resin bonded fixed dental prosthesis had variable popularity since the technique for splinting anterior teeth with a perforated metal casting was described by Rochette in 1973  These retainers usually consists of one or more pontics supported by thin metal retainers placed on the lingual or proximal surface of abutments www.indiandentalacademy.com
  • 55.  Retention in these prosthesis is obtained by adhesive bonding between etched enamel and metal casting which are held in place by resin that locks mechanically into microscopic undercuts present on etched enamel and undercuts in casting www.indiandentalacademy.com
  • 56.  Based on the technique used to finish the tissue surface ,the retainers are classified as 1. Rochette bridge 2. Maryland bridge 3. Cast mesh FDP 4. Virginia bridge www.indiandentalacademy.com
  • 57.  Mandibular incisor replacement  Maxillary incisor replacement ,if they are in open bite, end to end or moderate overbite  Short span fixed partial dentures  Carious-free abutments  Single posterior teeth replacement  Periodontal splints www.indiandentalacademy.com
  • 58.  Extensive caries  Para functional habits  Long edentulous spans  Restored or damaged abutments  Significant pontic width discrepancy  Deep vertical overlap  Nickel allergy www.indiandentalacademy.com
  • 59.  Minimal removal of the tooth structure  Minimal potential for pulpal trauma  Supra gingival preparation, help in finishing and polishing the restoration  Ease in impression making  No requirement for the provisional restoration  Reduced/less chair time  Less expensive www.indiandentalacademy.com
  • 60.  uncertain longevity  Enamel modification are required  Space correction is difficult  Good alignment of the abutments required  Difficult temporization  Esthetics is compromised on posterior teeth   www.indiandentalacademy.com
  • 61.  Radicular retained prosthesis consists of of a post and dowel with attached core that obtains its retention and resistance to the displacement from the prepared root portion of an endodontically treated teeth  While the root preparation retains the core establishes retention and resistance for a complete veneer crown that restores the pulpless tooth to a normal form and function   www.indiandentalacademy.com
  • 62. 1. Conservation of the tooth structure  Minimal removal of tooth structure must be accomplished thus, avoiding weakening of the canal  Preservation of coronal tooth structure as much as possible which avoids the stress concentration at the gingival margin www.indiandentalacademy.com
  • 63. 2.Retention form  Retention of the post is affected by the preparation geometry, post length, post diameter, surface texture, and luting agent which is used to cement the post.  Unlike for the anterior teeth, long post with circular cross section should be avoided in the posterior teeth, which often have curved roots. For these teeth retention is better provided by relatively short post in the divergent canals   www.indiandentalacademy.com
  • 64. 3. Resistance form  Greatest stress concentration is found at the shoulder particularly inter proximally  Stress are reduced as post length increases  Parallel sided post may distribute stresses more evenly than the tapered post  Sharp angles should be avoided because they produce high stress during function  Threaded posts can produce high stress concentration during insertion and loading   www.indiandentalacademy.com
  • 65.  DOWEL CLASSIFICATION(POST) 1.CUSTOM CAST DOWELS 2. PREFORMED DOWELS  tapered smooth sided.  Tapered serrated posts.  Tapered threaded posts.  Parallel threaded posts.  Parallel serrated posts.  Parallel smooth sided posts. www.indiandentalacademy.com
  • 66. POST LENGTH    Retention will be proportional to the post length.  The standard parameters for the post length in a tooth with a normal periodontal support. Range from  2/3 of the length of the canal  coronal length of the tooth  half the bone support length of the root  the root morphology plays an important role in the retention of post.   www.indiandentalacademy.com
  • 67. POST SHAPE.    Placement of a parallel sided post with in the canal improves both the retention and force distribution of the post.  parallel sided post are 2-4 times more retentive compare to the other designs www.indiandentalacademy.com
  • 68. POST DIAMETER  The post must be sufficient diameter to resist functional forces.  Larger diameter gives little or no improvement in the dowel to root retention but significantly reduces the resistance of the tooth to fracture.   www.indiandentalacademy.com
  • 69. SURFACE CONFIGURATION  The surface of the post can be serrated, smooth or threaded.  Serrated surface provides mechanical undercuts for cement and significantly increase retention of the parallel posts over that of smooth surface   www.indiandentalacademy.com
  • 70. POST MATERIAL  Material used in the post must be able to withstand the functional stress and resist corrosion and must not be harmful to the patients.  Custom cast posts are fabricated from gold alloys.  Prefabricated parallel sided posts are made of platinum-gold-palladium, nickel-chromium and cobalt – chromium.  Serrated posts come in either stainless steel or gold alloys.  Tapered posts are available in Pt-Au-Pd and Ni-Cr alloys.   www.indiandentalacademy.com
  • 71. CORE  The core consists restorative material placed in the coronal area of the tooth. The material replaces carious, fractured, or otherwise missing coronal structure and retains the final coronal restoration.  The core is anchored to the tooth by a direct connection of the core into the canal or through the endodontic dowel. the attachment between tooth, dowel, and core is mechanical, chemical, or both. www.indiandentalacademy.com
  • 72. Desirable properties of the core material includes.  high compressive strength  ease of manipulation  dimensional stability  Short setting time. www.indiandentalacademy.com
  • 73. Various causes for failures of retainers are 1. Cementation failure 2. Mechanical breakdown 3. Gingival irritation 4. Periodontal breakdown 5. Caries 6. Loss of retention 7. Inadequate bridge design 8. Incomplete castings www.indiandentalacademy.com
  • 74. 1.Cementation failure may be partial or complete due to a. Result of retainers inadequate for bridge b. Flexion of casting c. Poor cementation technique such as -wrong choice of material -use of old contaminated stock -inadequate powder liquid ratio -improper isolation -failure to follow manufacture instructions www.indiandentalacademy.com
  • 75. 2.Mechanical breakdown a) flexion, tearing, fracture of alloy b) Solder joint failure due to inadequate width and depth c) Pontic failure due to inadequate strength and faulty occlusion 3.Gingival irritation a) Poor oral hygiene b) Faulty margins of retainers c) Incorrect occlusal anatomy www.indiandentalacademy.com
  • 76.  Over contouring of buccal and lingual aspects  Inadequate inter proximal embrasures  Improper pontic design Poor fitting full crown causing ulcerative gingivitis www.indiandentalacademy.com
  • 77. www.indiandentalacademy.com
  • 78. www.indiandentalacademy.com
  • 79. Loss of retention a) Inadequate tooth preparation b) Poor cementation technique c) Caries d) Leverage forces on the bridge Incomplete casting a) Occlusal defects b) Pits and voids on inner surface of casting www.indiandentalacademy.com
  • 80.  A well organized approach and diagnosis of the practitioner is needed for the lifespan of the bridge. There fore, the selection of the retainers is very important for the longevity of the fixed dental prosthesis www.indiandentalacademy.com
  • 81. A. H.T.Shillingburg: fundamentals of fixed prosthodontics B. 3rd edn QB 2002 C. Rosenstiel: cotemporary fixed prosthodontics 4th edn Mosby 2002 D. D C N A: ceramics oct 1977 21;4 E. M.A.Marzouk; Operative Dentistry .Modern theory and practice 1997 F. Shillingburg; fundamentals of tooth preparation for cast metal and porcelain restoration QB 1987 G. D.H.Roberts: fixed bridge prosthesis 2nd edition H. Tylman: theory and practice of fixed prosthodontics,7th edition I. Jpd 2006oct,96(4):245-51 J. Jpd 1996 june,75(6):591-3 K. Jpd 2003:90,31-41 L. Jpd 2003;92:13-16 M. www.indiandentalacademy.com
  • 82. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com