Loading…

Flash Player 9 (or above) is needed to view presentations.
We have detected that you do not have it on your computer. To install it, go here.

Like this presentation? Why not share!

unconventional fpd

on

  • 158 views

 

Statistics

Views

Total Views
158
Views on SlideShare
158
Embed Views
0

Actions

Likes
0
Downloads
5
Comments
0

0 Embeds 0

No embeds

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment
  • Conservation of the tooth structure has been one of the main goals of restorative dentistry. Conventional procedures for the preparation of abutment teeth often involve major removal of tooth structure. However, when the abutment is sound, conventional full coverage procedures seem quite radical <br /> More conservative procedures, such as partial veneer crowns or pin-retained restorations, present limitations in esthetics and retention. Many patients object to these drawbacks and consequently choose removable partial dentures which may not be used. Recent innovations in the acid-etch technique have led to new alternatives to traditional treatment for esthetic and restorative procedures. <br />
  • Goal: <br /> The primary Goal of the resin retained fixed partial denture is the replacement of missing teeth and maximum conservation of tooth structure. <br />
  • In 1973, Rochette introduced the concept of bonding <br /> metal to teeth using flared perforations of the <br /> metal casting to provide mechanical retention. He <br /> used the technique principally for periodontal <br /> splinting but also included pontics in his design. <br /> Howe and Denehy recognized the metal framework&apos;s <br /> improved retention (as compared to bonded <br /> pontics) and began using FPDS with cast-perforated <br /> metal retainers bonded to abutment teeth and <br /> metal-ceramic pontics to replace missing anterior <br /> teeth. Their design recommendation, extending the <br /> framework to cover a maximum area of the lingual <br /> surface, suggested little or no tooth preparation. Patient <br /> selection limited these FPDs to mandibular <br /> teeth or situations with an open occlusal relationship. <br /> The restorations were bonded with a heavily <br /> filled composite resin as a luting medium. <br /> This concept was expanded to replacement of <br /> posterior teeth by Livaditis. Perforated retainers <br /> were used to increase resistance and retention. The <br /> castings were extended interproximally into the <br /> edentulous areas and onto occlusal surfaces. The <br /> design included a defined occlusogingival path of <br /> insertion by tooth modification, which involved <br /> lowering the proximal and lingual height of contour <br /> of the enamel on the abutment teeth. These restorations <br /> were placed in normal occlusion; many have <br /> survived and have been seen on recall for up to 13 <br /> years (Fig. 26-2). Despite this success, the perforation <br /> technique presents the following limitations: <br /> • Weakening of the metal retainer by the <br /> perforations <br /> Exposure to wear of the resin at the perforations <br /> Limited adhesion of the metal provided by the <br /> perforations <br /> Clinical results with the perforated technique <br /> were followed for 15 years in a study at the University <br /> of Iowa.&apos;-&apos; The results from this well-controlled <br /> Fig. 26-2. Lingual view of an early perforated resinbonded <br /> FPD replacing a premolar at the 13-year recall. Note <br /> the loss of resin from the perforations, the poor gingival embrasures, <br /> and the generalized wear of the occlusal composite <br /> resin restoration on the molar abutment. <br /> study suggest that for anterior fixed partial dentures, <br /> 63% of the perforated retainer prostheses fail <br /> in about 130 months.&apos;6 Later data&apos;-&apos; indicate that 50% <br /> fail in about 110 months (Table 26-1). <br />
  • The slots in the proximal surface of adjacent teeth are prepared 1.5 mm towards pulp cavity and 0.5 mm gingivally as an interlocking mechanism. This type of preparation will prevent gingival movement of the bridge as well as provide retention. <br /> The bridge post is then inserted into the pontic channel in the fung shell provided and slide into the prepared abutment teeth, and adjustments are made accordingly. <br /> The fung shell can be adjusted for proper contact with tissues with a bur. <br /> The fung shell bridge is cemented using light curing composite, and finished and polished. <br />
  • The alloy framework should be designed to engage at least 180 degrees of tooth structure when viewed from the occlusal. This proximal wrap allows the restoration to resist lateral loading by engaging the underlying tooth structure. It should not be possible to remove a properly designed resin bonded F.P.D. in any direction but parallel to its path of insertion <br />
  • Primarily mechanical bonding is subdivided into: <br /> 1) Micro mechanical retention - which uses etching to create microscopic porosities and <br /> 2) Macro mechanical retention - which relies on visible undercuts usually with a mesh or pitted metal. <br /> Chemical bonding generally employs tin plating of metal framework and specific resin adhesives for metal and enamel. <br />
  • One of the basic principles of tooth preparation for fixed prosthodontics is conservation of tooth structure. <br /> This is the primary advantage of resin-retained FPDs. <br /> Precision and attention to detail are just as important in resin-retained fixed partial dentures as they are in conventional prosthesis. <br /> Careful patient selection is an important factor in predetermining clinical success. <br />

 unconventional fpd unconventional fpd Presentation Transcript

  • GOOD MORNING
  • 2 UNCONVENTIONAL FIXED PARTIAL DENTURES
  • Contents  Introduction  Classification  Resin bonded fixed partial dentures Definition Advantages Disadvantages Indications Contraindications Types 3
  •  Procedures 1. Tooth preparation 2. Fabrication of the frame work 3. Bonding of the restoration  Fiber Reinforced Composite Resin FPD  F i x e d / d e t a c h a b l e ( h y b r i d )  Summary  References 4
  • 5 Introduction
  • 6 Fixed- fixed Fixed- movable Cantilever H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • Spring cantiliver 7 hybrid prosthesis H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • 8 Resin retained fixed partial dentures
  • DEFINITION According to the glossary of prosthodontic terms Resin bonded prosthesis: A prosthesis that is luted to tooth structures primarily enamel which has been etched to provide mechanical retention for the resin cement. Goal: Replacement of missing teeth and maximum conservation of tooth structure. 9
  • Advantages 1. Minimal removal of tooth structure. 2.Non invasive to dentin 3. Minimal potential for pulpal trauma. 4. Tissue tolerant because of supragingival margins without gingival irritation. 10 H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 3rd ed
  • 5. Esthetically more appealing since only lingual surface of anterior teeth are covered 6. No anesthesia hence less trauma to patient. 7. Simplified impression procedures 8. Interim restorations usually not required. 11 H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 3rd ed
  • 9. Reduced chair side time 10. Reduced patient cost… 11. Re-bonding possible. 12Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed. Mosby Harcourt brace and Co; 2001
  • Disadvantages 1. Reduced restoration longevity 2. Enamel modifications are required 3. Good alignment of teeth are needed 4. Very thin or translucent anterior teeth are limiting factor because of esthetics. 5. Usually restricted to single tooth replacement 13 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • 6. No space and alignment correction. 7. Difficult temporization. 8. Uncertain longevity. 9. Esthetics is compromised on posterior teeth replacement. 14 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • INDICATIONS 1. Replacement of congenitally missing tooth or teeth lost by traumatic injuries especially in young patients. 2. Splinting of periodontally compromised teeth. 3. Stabilizing dentition after orthodontic treatment or movement. 4. Short span and in case on open bite. 15 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • 5. Retainers of FPD for abutment with sufficient enamel to etch for retention. 6. Significant crown length. 7. Unrestored abutments. 8. Medically compromised and adolescent patients. 16 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • CONTRAINDICATIONS 1. Patients sensitivity to base metal alloy. 2. Parafunctional habits. 3. Long span involving 3 or more abutments. 4. Restored or damaged abutments. 5.Compromised enamel. 17 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • 6. Significant pontic discrepancy. 7. Deep vertical overlap. 8. When facial esthetics of abutment require improvement eg: stained, malformed or malposed teeth. 9. Insufficient occlusal clearance to provide 2-3 mm vertical retention. eg: abraded teeth. 10. Incisors with extremely thin facilingual dimension 18 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Types Of Resin Bonded Fixed Partial Denture Designs 1) Rochette 2) Maryland 3) Virginia 4)Fungs 19
  • CAST PERFORATED RESIN-RETAINED FPDS: (ROCHETTE BRIDGE) Alain Rochette in 1973 introduced this type of bridge. Bonding through mechanical retention. The metal retainer had flared perforation so that the bonding material gets locked mechanically. 20 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • To prevent weakening of the framework- Too large and too closely placed perforations should be avoided. The perforations should be approximately 1 mm apart and have a maximum diameter of 1.5mm. 21 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Replacement of posterior teeth – Livaditis Extension – interproximally and onto occlusal surfaces. Survival rate -3 years 22 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • ADVANTAGES 1) It is easy to see the retentive perforations in the metal. 2) If the bridge must be replaced, the composite resin can be cut away in the perforations to aid in the removal process. 3) No metal etching is required. 23 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Disadvantages 1) The perforations would weaken the retainers if improperly sized or spaced. 2) The exposed resin is subjected to wear. 3) It is not possible to place perforations in proximal surface or in the rest. 24 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • ETCHED CAST RESIN RETAINED FPDS: (MARYLAND BRIDGE) Thompson and Livaditis developed this type of FPD at University of Maryland. The retention is micro mechanical ie, through electrolytic etching of Ni-Cr and Cr-Co 25
  • Lividatis and Thompson used a 3.5% solution of nitric acid with a current of 250 mA/cm for 5 min, Followed by immersion in an 18% hydrochloric acid solution in an ultrosonic cleaner for 10 min This technique was specific to non beryllium nickel chrome alloy. 26 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Thompson et al reported that 10% sulphuric acid at 300 mA/cm2, followed by same cleaning methods, would produce similar results in beryllium containing nickel chrome alloy. 27 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Advantages 1. It is reported to have improved bond strength. 2. Retention is improved because the resin-to- etched metal bond can be substantially stronger than the resin-to-etched enamel. 3. Instead of perforations, the tooth side of the framework is electrolytically etched, which produces microscopic undercuts. 28 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • 4. It can be used for both anterior and posterior bridges 5. The retainers can be thinner and still resist flexing. 6. The oral surface of the cast retainers is highly polished and resists plaque accumulation. 29 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Disadvantages Although this design has been reported to be stronger, it is more technique sensitive because the retainers may not be properly etched or may be contaminated before cementation. Because the retentive features are not seen with the unaided eye the etched surface must be examined with a microscope to verify proper etching. 30 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • 3. MACROSCOPIC MECHANICAL RETENTION RESIN RETAINED FPD: (VIRGINIA BRIDGE) Moon and Hudgins et al produced particle roughened retainers by incorporating salt crystals into the retainer patterns to produce roughness on the inner surfaces. This method is also known as lost salt technique 31 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • LOST SALT TECHNIQUE The framework is outlined on the die with a wax pencil and the area to be bonded is coated first with model spray and then with lubricant. Sieved cubic salt crystal (NaCl), ranging in size from 150 to 250 mų are sprinkled over the outlined area. 32 The retainer patterns are fabricated from resin leaving 0.5 to 1.0mm wide crystal free margin from the outlined area. Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Application of resin pattern Pattern investment,salt crystals are dissolved from the surface 33 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Cast mesh retainers 34
  • Fung shells
  • Advantages 1. It is of lower cost compared to custom made resin – bonded bridges. 2. No need of impression making and laboratory work. 3. Can be given to patient in a single appointment. 4. Good esthetics no exposure of metal in proximal areas. 5. Longevity comparable to resin bonded bridges http://www.fung-international.com/pdf/DI.pdf
  • FABRICATION of RBFPD 38 In fabrication of resin retained fixed partial dentures, all three phases are necessary for predictable success: 1) Preparation of abutment teeth. 2) Design of restoration 3) Bonding of restoration. Whether anterior or posterior teeth are prepared common principles dictate tooth preparation design.Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • 39 Anterior tooth preparation and frame work design H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • The finish line on the proximal surface adjacent to the edentulous space should be placed as far facially as is practical. Abutments should have parallel proximal surfaces. 40 H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • An optional slot, O.5mm in depth, prepared with a tapered carbide bur, may be placed slightly lingual to the labial termination of the proximal reduction. 41 H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • 42 Leave the margins about 1mm for the incisal or occlusal edge and 1mm supragingival if possible. Wherever possible to enhance resistance more than half the circumference of the tooth should be prepared. H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • Preparation of mandibular anterior teeth is similar to that for the maxillary incisors. Lingual enamel thickness is 11 to 50 percent less than for maxillary teeth and consequently tooth preparation must be more conservative. 43
  • Posterior tooth preparation and framework design The basic framework consists of three major components. 1. The occlusal rest (for resistance to gingival displacement) 2. The retentive surface (for resistance to occlusal displacement) 3. The proximal wrap (for resistance to torquing forces). 44 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • A spoon shaped occlusal rest seat is placed in the proximal marginal ridge area of the abutments adjacent to the edentulous space. An additional rest seat may be placed on the opposite side of the tooth. 45 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • To resist occlusal displacement, the restoration is designed to maximize the bonding area without unnecessarily compromising periodontal health or esthetics. 46 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Proximal and lingual walls are reduced to lower their height of contour to approximately Imm. The proximal wall are prepared so that parallelism results without undercuts. 47 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • The bonding area can be increased through extension onto the occlusal surface provided it does not interfere with the occlusion. Generally a knife- edge type of margin is recommended. 48 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • . 49 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • In general, the preparation differs between maxillary and mandibular molar teeth on the lingual surface only. The lingual wall of mandibular tooth may be prepared in a single plane and the palatal surface of maxillary molars dictates a two plane reduction due to taper of these centric cusps in the occlusal two thirds and occlusal function. 50 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Resin to metal bonding Metal resin bonding can be classified as either 51 Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed.
  • Electrolytic etching: In this procedure microscopic porosity is created in the fitting surface of a nickel chromium framework by electrolysis. Procedure Clean the fitting surface of metal restoration with an air abrasion unit with aluminium oxide. Cover the polished surfaces with wax and attach the prosthesis to an electrolytic etching unit following the manufacturers instructions. 52 Michel Degrange: Minimally invasive restoration with bonding
  • A typical etching cycle will be 3 minutes in 10% H2SO4 with a current of 300 milliamp per square centimeter of casting surface. Clean the etched surface ultrasonically in 18% HCI, then wash and air-dry it. The etched surface must not be handled after this stage. 53 Michel Degrange: Minimally invasive restoration with bonding
  • Chemical etching A gel consisting of nitric and hydrochloric acid is applied to the internal surface of the metal framework for approximately 25 minutes. As electrolytic etching is extremely sensitive, many authors believe that chemical etching provides more reliable results due to procedural simplicity. 54 Michel Degrange: Minimally invasive restoration with bonding
  • Silicoater Classical Tiller et al (1984) Procedure – sand blasting of alloy Flame coating of silica-carbon for 5 minutes,thus the surface bonds to composite Disadvantage – 1. Expensive 2. Uneven distribution of flame 3. Chemically unstable silica layers 4. Protection of the layer formed 55 Michel Degrange: Minimally invasive restoration with bonding
  • Rocatec System Introduced in 1989 The metal surface is abraded with 120microns alumina Followed by abrasion with silicate particle- containing alumina. Silane application thus adhesive to composite resin. 56
  • MACROSCOPIC RETENTION In non-perforated retainer, porosity is cast in the pattern itself rather than subsequently obtained by etching. This is done in variety of ways: 1. Lost salt technique. 2. One techniques uses a special pattern to form a meshwork on the fitting surface and the external lingual surface is waxed to give a smooth finish that can be highly polished. 57
  • Advantages 1. any alloy can be selected, whereas with electrolytic or chemical etching the alloy usually must be nickel chromium. 2. try-in and bonding of the prosthesis can be accomplished at the same appointment. 58
  • Disadvantages 1. Difficulty on adapting the mesh to create a closely fitting metal framework 2. A potentially thicker metal framework than can be obtained with a etched metal retainer 3. The rate of microleakage along the cast mesh composite resin interface is significantly greater than along an etched metal resin interface 59
  • Tin plating is a recently introduced procedure that can improve the strength of adhesive cement to most metals. Precious alloys can be plated with tin and used as frameworks for resin retained fixed partial dentures. Tin forms organic complexes with several specific adhesive resin cements that result in 60 TIN PLATING (CHEMICAL BONDING)
  • BONDING AGENTS Composite resins play an important role in the bonding of the metal framework to etch enamel. They conatin I) Filled BisGMA composite resin (Bisphenol A glycidil methacrylate). 2) TEGDMA (Triethylene glycel dimethacrylate). 3) 4META (4 methacrylyloxethyl trimellifate 61
  • Cements with adhesion promoters PANAVIA Components: low viscosity paste, radio opaque composite resin paste Universal and catalyst Composition : Bisphenol-A-Polyethoxy dimetharyclate, MDP or 10-Methacrloxydecyl dihydrogen phosphate, 77%silanated organic fillers.
  • Mixing time : 20-30 sces Film thickness: 19 microns Metal surface must be sandblasted or tin coated. Recent version – PANAVIA F
  • C&B METABOND COMPOSITION: Methylmethacrylate polymer powder Mma liquid modified with 4-META or 4 Methacryloxyethyl Trimellitic Anhydride. Tri-n-Butyl Borane catalyst. Disadvantage-poor hydrolytic stability
  • Cementation procedure 65
  • 66 H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • 67 H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • 68
  • 69
  • Post operative care Regular recall visits Check for any debonding Caries Periodontal health H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • Fiber Reinforced Composite Resin FPD 1. Consists of a fibre reinforced substructure 2. Veneered with composite material 3. Increased flexural strength , fracture resistance & increased tensile strength 4. Transluscent H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • Types Of Fibres 1. Glass 2. Polyethylene 3. Polypropylene 4. Carbon H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • Orientation of the fibre 1. Unidirectional 2. Braided 3. Woven
  • Procedure 1. Preparation of abutment teeth 2. Measurement of fiber length 3. Moistening of fiber 4. Fiber bar pressed into the preparation & polymerised with resin 5. Pontic build up & curing H.T Shillingburg, . Fundamentals of fixed Prosthodontics. 1st ed
  • FIXED REMOVABLE FPD Fixed-movable Bridge– These are similar to fixed-fixed bridges but have a movable joint (not detectable by the patient) allowing the use of a bridge when retaining teeth that are not favourably aligned. Eg:- Andrews bridsge 75
  • FIXED REMOVABLE FPD Andrews bridges:- Fixed removable partial dentures are particularly indicated for patients with extensive supportive tissue loss and when the alignment of the opposing arches and/or esthetic arch position of the replacement teeth create difficulties 76 J Prosthet Dent. 1983 Aug;50(2):180-4
  • 77 A FIXED REMOVABLE PARTIAL DENTURE TREATMENT FOR SEVERE RIDGE DEFECT Int J Dent Case Reports 2011; 1(2): 112-118
  • SPRING CANTILEVER BRIDGE 78 . DEFINITION :                               It is a bridge that carry the  pontic by a tooth not       immediately related to it  and connect to it by a    flexible palatal bar.   .   . The  bar  must  sufficiently  flexibile  to  allow  it  to  be  pressed  on  to  and  gain  support  from  the  mucoperiosteum  during mastication
  • 79 1.Where aesthetics is of prime importance . 2.Where the teeth on either side of the space are unsuitable as abutments because there is insufficient retention or the teeth are periodontal disturbed and unable to carry additional load . 3.Where a Diastema is need to be preserved on one or both sides of the pontic . INDICATIONS :
  • 80 1.In young patients where the clinical crowns are short and of inadequate retention . 2.When the teeth on either side of the space need crowning in replacement of lower tooth . 3.When the shape of the palate is unfavorable . 4.Where there is sever soft tissue loss . 5. When the proposed abutment tooth is unopposed or CONTRAINDICATIONS :
  • 81 Pier abutments Tilted molars
  • CONCLUSION 82
  • References Textbook references: 1. Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics. 3rd ed. Mosby Harcourt brace and Co; 2001 2. H.T Shillingburg, Sumiya Hobo, Lowell D. Whitsett. Fundamentals of fixed Prosthodontics. 3rd ed. Quintessence Publishing CO, Inc; 1997 3. W.F.P. Malone, D.L Koth, E. Cavazos, Jr. Tylman's theory and practice of fixed th prosthodontics. 8 ed. Ishiaku Euro America .p.219-228. 4.Direct bonded retainers.Gerald McLaughlin 5.Minimally invasive restorations with bonding: Michel Derange/Jean-Francois Roulet 6.Resin Bonded Bridges:technique for success; K.A.Durey,P.J.Nixon BDJ2011;211:113-118 7.Quintessence International;Jul/Aug2009, Vol. 40 Issue 7, pe3 83
  • THANK YOU