Direct Filling Gold

direct filling gold... material aspect, types, condensation, cavity design, modifications. detaied seminar for post gradutes.... any doubts or suggestions contact [email protected]

1. DIRECT FILLING GOLD Dr. Madhu Billa I MDS DEPT OF CONSERVATIVE DENTISTRY AND ENDODONTICS SIBAR INSTITUTE OF DENTAL SCIENCES

2. CONTENTS INTRODUCTION HISTORY PROPERTIES INDICATIONS CONTRAINDICATIONS BIOLOGICAL CONSIDERATIONS DIFFERENT FORMS OF GOLD Dr.MadhuBilla

3. METHOD OF DEGASSING CONDENSATION TYPES OF CONDENSATION STEPS FOR PLACEMENT OF DFG FINISHING CAVITY PREPARATION CONCLUSION Dr.MadhuBilla

4. INTRODUCTION Among the available restorative materials, direct filling gold is the oldest filling material that is still used in restorative dentistry. The vision to utilize the noble metals for the replacement of lost tooth structure stemmed from perfect harmony of its biological and mechanical properties . Dr.MadhuBilla

5. While most of metals can be welded and alloyed at a temperature above the room temperature, the pure gold can be cold welded and made to adhere to each other at room temperature. For a pt gold foil means no second appointment, no second administration of L.A and no second application of rubber dam. Lastly as quoted by B.Smith it may serve the tooth for a lifetime. . SMITH B J OF SOTH CALIFORNIA STATE DENTAL ASSC. 1959 Dr.MadhuBilla

6. 1483- Giovanni d arcoll first recommended gold leaf as restorative material 1712-1786- Frederic used for pulp capping 1795 - Robert woffendale introduced gold foil for restoration purpose in America 1803 – Edword Hudson used goldfoil to fill root canal 1838- Dr .E. Meritt of pittsburg introduced hand mallet for compaction . HISTORY Dr.MadhuBilla

7. In 1840 Jackson first introduced sponge (Crystal or crystalline) gold which was easier to condense. In mid 1850’s Robert Arthur of Baltimore introduced the technique of heating pieces of sponge gold over a “Spirit lamp ” to make them cohesive 1892- Power And Bonwill developed the pneumatic hammer 1896- Bryan referred to mat gold Dr.MadhuBilla

8. 1964- Goldent powdered gold was introduced 1969 – R.V.Willams and C.Ingersoil introduced Electralloy 1980- E-Z gold were introduced by Baum 1989-new granular type of gold stopgold was introduced by Dhiek and Regelstein Dr.MadhuBilla

9. PROPERTIES Gold (Au) Atomic number – 79 Atomic weight – 196.966amu Melting point – 1064.43ºc Boiling point – 2807ºc Brinell’s hardness number – 25 Malleability - It exceeds all other metals in this respect. It may be reduced by beating to sheets of 1/250,000 of an inch in thickness. Ductility-It is most ductile of all metals Dr.MadhuBilla

10. INDICATIONS Incipient carious lesion Occlusal, buccal, lingual pit Class II lesions on premolars and molars Class III in mandibular anteriors Class V in bicuspids, cuspids (where esthetics permit) Erosion areas Dr.MadhuBilla

11. Atypical lesions Proximal lesions on teeth adjacent to crown preparations Class VI lesions Retrograde root canal filling material Dr.MadhuBilla

12. CONTRAINDICATIONS Very young and old patient Teeth with large pulp chamber Periodontal weakened teeth Economy is limited factor Handicapped patient Root canal treated teeth Dr.MadhuBilla

13. Under developed root Caries prone mouth Hypersensitive cavities Extensive cavities with weakened walls Lack of skill of operator Dr.MadhuBilla

14. ADVANTAGES Insoluble in oral fluids More resistant to tarnish and corrosion Perfect adaptation to cavity wall because of ductility More edge strength Low tendency to molecular change (free from shrinkage or expansion) Maintain high polish Advantages of direct gold filling by L.Clarke Operative dentistry 1985 10-22 Dr.MadhuBilla

15. No intra cement substance needed Thermal expansion similar to dentin Oral tissue accepts readily Causes no tooth discoloration Advantages of direct gold filling by L.Clarke Operative dentistry 1985 10-22 Dr.MadhuBilla

16. DISADVANTAGES Inharmonious color Thermal conductivity can be a problem in a newly restored teeth. Can lead to sensitivity to hot and cold Advantages of direct gold filling by L.Clarke Operative dentistry 1985 10-22 Dr.MadhuBilla

17. Manipulation of gold is difficult to master. It requires skill and practice Non-cohesive gold may be used on account of its rapidity of manipulation in simple cavities with four strong walls , located on surfaces not subject to wear. It is not indicated on surfaces subjected to stress of mastication or for contour work Advantages of direct gold filling by L.Clarke Operative dentistry 1985 10-22 Dr.MadhuBilla

18. Energy of condensation which is not absorbed by the restorative material, may dissipate to the pulp dentin organ Thermal energy in the pellet, exceeding that needed for decontamination – causes pulpal irritation Frictional heat of finishing and polishing Galvanic current between gold and other metallic restorations Ultrasonic energy from high condensation frequency can harm pulp BIOLOGICAL CONSIDERATIONS Dr.MadhuBilla

19. 3mm or more of remaining dentin thickness – no base 2mm or more of remaining dentin thickness – varnish on walls and floors, without cavo surface margins Between 1-2mm of remaining dentin thickness – sub base of calcium hydroxide or unmodified zinc oxide eugenol and over this varnish is applied. and zinc phosphate cement or zinc poly carboxylate base is used . Less than 1mm of remaining dentin thickness – direct filling gold contraindicated Need for base Dr.MadhuBilla

20. In a study done by D raheim et al., On the ability of cavity bases to withstand condensation of direct gold concluded that ZOE and calcium hydroxide containing bases have silmilar abilities to withstand condensations of direct filling gold Authors concluded that ZoE and calcium hydroxide cavity bases tested had adequate strength to resist the forces of condensation of electraloy The ability of cavity bases to withstand condensation of direct gold Quintessence International 11/1985 Dr.MadhuBilla

21. GOLD - TYPES GOLD FOIL ELCTROLYTIC PRECIPITATED GOLD Mat gold Mat foil Gold calcium alloy POWDERED GOLD/GRANULATED GOLD Gold dent Dr.MadhuBilla

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23. Gold foil: Gold foil sheets are manufactured by a process called gold beating or rolling All light weight sheets are formed by beating and heavy weight sheets are formed by rolling In beating process, first heavier mallets are used followed by lighter ones as gold gets thinner . Dr.MadhuBilla

24. For rolling, it is passed through rolling mills until desired thickness is got. It comes in a book of 1/10 or 1/20 ounces. One book has 12 sheets with a common dimension of 4 x 4 No. 4 gold foil weighs 4 grains ( 0.259gm) and is 0.51 µ m thick No. 3 gold foil weighs 3 grains (0.194gm) and is about 0.38µm thick Dr.MadhuBilla

25. During manufacture , pure gold ingots are subjected to cold working, thereby creating sheets out of blocks . As the gold is subjected to strain hardening during this process, for further cold working towards the formation of these leaves or sheets, the material should be subjected to proper annealing This alternate process of cold working and annealing - cold working continues until the desired thickness of the gold sheet is arrived at. Dr.MadhuBilla

26. Extra liable gold foil : It was made to produce a more cohesive gold Extra labile gold has improved tendency to cohere Formed by wrapping a loosely formed, regular gold rope with an extra sheet of gold foil Dr.MadhuBilla

27. Gold foil pellets: May vary from ½ - 1/128th of a portion of No. 4 gold foil After removing the gold foil along with the tissue paper from the book. Foil is held on paper and is cut to the size needed. Paper supports the thin gold foil and prevents it from tearing and wrinkling during manipulation Dr.MadhuBilla

28. Sizes used are from 1/10 onwards. Larger sizes of 1/2, 1/4, 1/8 are used for making cylinders. The desired piece is then grasped by index, thumb and middle finger of left hand. Ends are touched with tweezers towards the center and are rolled into loose balls Pellets are degassed and stored in separate compartment Dr.MadhuBilla

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30. Gold cylinder Can be hand rolled or commercially rolled Made by rolling the cut segment of No. 4 foil into 1/2, 1/4, 1/8 widths Dr.MadhuBilla

31. Corrugated gold / carbonized gold foil T his was first observed by a dental dealer in the great Chicago fire of 1871 . Corrugated gold foil is manufactured by placing a thin leaf of paper between two sheets of gold foil, after which the whole container accommodating paper leaves and gold foil is ignited. As the paper leaves are burned out, they shrivel, and thereby impart a corrugated shape to the gold foil It has been proven that corrugated gold foils are more cohesive than the plain ones. Dr.MadhuBilla

32. Platinised gold foil: It’s a sandwich of gold and platinum with platinum content being 15% One sheet of platinum foil is sandwiched between two sheets of gold foil and is then hammered to the thickness of NO. 4 gold foil Layers of gold and platinum are rolled over together so that there occurs fusion of the two even before the beating procedure begins Platinum increases the hardness and wear resistance of the restoration. So this form can be used in stress concentration areas like incisal edges and cusp tips. Dr.MadhuBilla

33. When a cube of gold ingot is cold worked in order to formulate a sheet, the cubical crystals of gold will he stretched and elongated in a specific direction. If the gold foil of that cube is viewed under a microscope. It appears fibrous, with the fibers parallel to each other in a specific pattern. Mechanically speaking, this type of gold foil material will have directional properties, i.e., It will be resistant to stresses in one direction better than the other. LAMINATED GOLD FOIL Dr.MadhuBilla

34. The idea of laminated gold foil is to combine two or three leaves of gold, each from different ingots which have been cold worked in different directions. Although each leaf will be directional in its properties, when combined together, they can be resistant in different directions. Therefore , laminated gold foil is definitely much stronger and much more resistant to stresses than the other forms of direct gold materials. Dr.MadhuBilla

35. Cohesive gold: Is that form of gold which is essentially free of any surface contaminants and can be placed directly into the cavity Gold can attract gases to its surface, and any adsorbed gas film can prevent intimate atomic contact required for cold welding. So manufacturer supply the foil free of surface contaminants and therefore inherently cohesive this type is reffered to as cohesive foil. Dr.MadhuBilla

36. Semi cohesive gold: Some gold sheets have adsorbed protective gas film such as ammonia. This minimize the adsorption of other less volatile substances and prevent premature cohesion of sheets . The volatile film is readily removed by heating to restore the cohesive character of the foil. This type is reffered to as semi cohesive gold Dr.MadhuBilla

37. Non cohesive gold: Non volatile contaminants like iron, sulphur , phosphorous are permanently deposited on the surface. This cannot be driven away by heat and so gold loses it cohesive property. Non cohesive forms are used as starting material, since they can be worked more easily than cohesive forms. But they don’t have good strength and hardness. Dr.MadhuBilla

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39. MAT GOLD It is an electrolytically precipitated crystalline form that is sandwiched between sheets of gold foil and formed into strips These strips are cut into desired sizes Preferred for its ease in building up the internal bulk of the restoration as it can be more easily compacted and adapted to the retentive portions of the prepared cavity Dr.MadhuBilla

40. As it is loosely packed it is friable and contain numerous void spaces between the particles So it is recommended for the external surface of the restoration Using this two material technique the mat is covered with veneer of foil Loosely packed crystalline form with large surface area of the mat powder it does not permit easy welding into a solid mass as does gold foil Dr.MadhuBilla

41. Advantages: Rapid filling, Filling Internal bulk (cavity walls ,and retentive portions) It is used to form the core of the restoration Average size is 10 to 20µm Dr.MadhuBilla

42. Disadvantages: Difficult to handle, Voids ,surface pitting, and ditching, rough finishing, More condensation pressure required, crumbles during manipulation Does not permit welding into homogenous mass Dr.MadhuBilla

43. MAT FOIL This is a sandwich of Mat Gold placed in sheets of No 3 / 4 gold foil. The sandwich is sintered by heating to just below the melting point of gold and cut into strips of different widths The gold foil cover holds the crystalline gold together while it is being condensed. Mat Gold Foil By Koser And Ingraham Operative Dentistry Vol 52 1956 Dr.MadhuBilla

44. Mat gold foil differs from the so-called cohesive type foils. It is a fine, electrolytic, crystalline deposit made adhesive by the nature of its finely divided crystalline structure and by the extremely pure state of the metal itself. Its mechanical strength is the result of a special molding and heat treatment process. This property renders it easier to manipulate. Because mat gold foil is highly adhesive and cohesive, and because it is more readily adaptable than other types of foil, it is ideally suited for building up the internal bulk of Class V, Class I and the occlusal portion of Class II restorations . Dr.MadhuBilla

45. ALLOYED ELECTROLYTIC PRECIPITATE This is an alloy of electrolytic gold and calcium The calcium content is usually 0.1- 0.5 % by weight Its purpose is to produce stronger restorations by dispersion hardening. For convenience, the product is sandwiched between two layers of gold foil Dr.MadhuBilla

46. ELECTROALLOY R.V. This is a mat gold manufactured by Williams Gold Refining Company, New York. R.V stands for R.V. Williams who developed this Dr.MadhuBilla

47. POWDERED GOLD It is a blend of atomized and precipitated powder embedded in a wax-like organic matrix. This form was introduced in 1962 by B aum and L und. The atomised and chemically precipitated powders are first mixed with a soft wax to form pellets These wax gold pellets are wrapped with foil The resulting pellets are cylindrical and are available in different diameters and length Dr.MadhuBilla

48. Commercially available pellets of powdered gold wrapped in a gold foil are known as “ goldent ” Introduced in 1960’s The individual particles or granules are of 15µm are gathered into mass of irregular shape ranging in size from 1-3mm precondensed lightly to facilitate handling These masses are encased in an envelope of foil to make it easier to convey them to the cavity Dr.MadhuBilla

49. E- Z Gold It is similar to Goldent but with improved working properties marketed by Williams Gold Refining Company, New York, introduced in the late 1980s It is a mixture of pure gold powder and wax (less than 0.01% organic wax), wrapped in gold foil Its manipulative characteristics are similar to stiff amalgam yet more cohesive than gold foil hence the name e-z gold EZ-Gold The New Goldent By Alperstein , Yearwood Jod 1996,21, 36-41 Dr.MadhuBilla

50. metallurgically similar to gold foil and powdered gold ( Goldent ) in that, when properly and thoroughly compacted, it has comparable properties: inertness (biocompatibility) and permanence. It is recommended for use in small class-I and class-V LESIONS It is less time consuming and more predictable Greater expected longevity and more favourable tissue response Dr.MadhuBilla

51. Stopfgold : a new direct filling gold A new direct gold material that is considerably different from other direct golds has been available since 1989. The advantages are that the final restoration exhibits greater density than other forms of granular gold and has a 50% increase in shear strength when compared to gold foil. Clinical experience with the use of this new restorative material has been encouraging. Stopfgold : a new direct filling gold. Lambert RL; [ Oper Dent] 1994 Jan-Feb; Vol. 19 (1), p. 16-9. Dr.MadhuBilla

52. REMOVAL OF SURFACE IMPURITIES /ANNEALING HEAT TREATMENT/DEGASSING Degassing -Remove the surface impurities (ammonia gas, wax ,other gas) Annealing: Remove the surface impurities with internal stress relief, restores ductility and malleability Annealing temperature ranges from 650°to 700°c,depended on selected method and heating time Produce an atomically clean surface result in metallic bonding Dr.MadhuBilla

53. OPEN ALCHOHOL FLAME METHOD Also called as piece method Heating unit used is open flame Absolute or 90% ethyl / methyl alcohol without any additives was used to produce a clean blue flame Gold foil is held with a instrument and heated over a clean blue flame of absolute alchohol METHOD OF DEGASSING Dr.MadhuBilla

54. Gold is passed over the blue flame ( reducing zone/middle zone) for 3-5 sec Temperature of the flame is 1300ºF and heating is done until gold becomes dull red Advantages: Less contamination Less wastage of the material Desired size of piece can be selected Disadvantages: Time consuming. Dr.MadhuBilla

55. 2.BULK METHOD MICA TRAY OVER A FLAME METHOD: A sheet of mica can be used over any type of flame and is used somewhat as a heating element. Divide the surface of the mica into several areas to indicate the time the pieces of gold were put on the mica Maximally five minutes are allowed for any piece of gold to be heated on mica Degassing of several gold pellets at the same time is possible Dr.MadhuBilla

56. ELECTRIC ANNEALING This is the most controlled and standardized way of decontaminating gold materials. With this instrument, the heated compartment area is made of aluminum. An electric heater controls the time and the temperature. The surface of the heater is divided into small compartments. each accommodating a piece of direct gold . This eliminates the possibility of cohesion of the pieces before they are inserted into the cavity preparation. Maximally , five minutes are allowed for any piece to be kept in the electric decontaminator. Dr.MadhuBilla

57. Electric annealing is maintained at temperature 343degree C (640 F)- 371degree C (700 F) Used for powdered gold to burn away wax Disadvantage: stick together if the tray is moved, size selection among the piece of degassed gold is limited , more chance of contamination . Dr.MadhuBilla

58. Heating time depend on size and configuration of gold segment (powdered gold-15-20 sec, gold foil pellet, electrolytic gold -1-2 sec) Avoid over heating and under heating Over heating : recrystallization, grain growth Incorporation of impurities ,more stiffness, less ductile, difficult to condense, non cohesive, particles adhere to each other, excessive sintering Under heating : partial cohesiveness, peeling away of adjacent segment or layer, pitting, porosity in final restoration Dr.MadhuBilla

59. Precautions to be taken using flame: Lamp should not run out of fuel during procedure There should be no surface contaminants on lamp and wick wick should be properly trimmed and rounded to produce a tear drop flame sulphur in matches could adhere to the wick and contaminate the gold. So ignite with other end of the match Dr.MadhuBilla

60. STORAGE OF GOLD FOIL Gold is packed into the preparation under pressure so that under welding minimal porosity occurs Protecting Gold Foil from contamination by gases with a thin film of alkaline salts. This protective film, usually of ammonia, prevents deleterious gases from condensing directly on the Foil. Instead, these gases combine with ammonia , to form other salts, and they are neutralized by it when it is present in excess. They are then driven off by annealing. Dr.MadhuBilla

61. Condensation /compact ion Objectives: Two main processes which control the quality of final direct gold restorations are welding and wedging. Welding: process of forming atomic bonds between pellets, layers of gold as a result of compaction Wedging: process of pressurized adaptation of gold form within the space between tooth structure walls or corners minimizing voids between margin of tooth and surface of gold. Dr.MadhuBilla

62. PRINCIPLES OF CONDENSATION 1. Force of condensation must be 45° to the cavity walls and floors, Bisect the line angle and trisect the point angle (result in maximum adaptation ,minimum irritation to vital pulp and dentin Dr.MadhuBilla

63. 2.forces of condensation must be directed at 90 degrees to previously condensed gold 3. always start at point angle on one side and proceed to other side. (tie formation) Ensure condenser has covered entire piece of gold Condenser has to over lap at least ½ of the previously condensed area Dr.MadhuBilla

64. 4. use minimum thickness of pellet as possible 5 Energy of condensation : Less energy is used inside cavity preparation Gradually increase the energy of condensation as build up proceeds to surface Maximum energy is used at surface of restoration Dr.MadhuBilla

65. 6. Condensation can be either from one periphery of the increment to other or preferable from center of the increment to periphery (reduces voids , air entrapment) Dr.MadhuBilla

66. CONDENSERS Condensors are used to deliver forces of compaction to DFG These condensors have three Parts: Handle shank , nib (working end ) Dr.MadhuBilla

67. CONDENSER NIB : Common feature of all Condenser are faces are serrated with pyramidal shape configuration Conensors based on Shapes of nib : Round condenser/bayonet condenser -used starting, nib face is 0.4 to 0.55mm Parallelogram and hatchet condenser - preliminary condensation, create bulk in restoration, nib face is approximately 0.5x1mm Varney Foot condenser - has rectangular face, it measures approximately 1x1.3mm - used for bulk built up Dr.MadhuBilla

68. CONDENSER SHANKS Availabl e as : straight , monoangle , offset , binangle Condenser used for hand malleting have longer shank, than condensors used in other mechanical means. Dr.MadhuBilla

69. Force required for compaction is proportional to size of nib of the condenser. Force delivered by compaction is inversely proportional to size of the nib of the condenser. Smaller the nib face more square inch force is delivered f = 1/d2 (d is reduced by ½, force /square inch delivered by condensation increase by 4 times more) Dr.MadhuBilla

70. There are several methods for the application of these forces: Hand pressure Hand malleting Automatic hand malleting Electric malleting Pneumatic malleting Dr.MadhuBilla

71. METHODS OF CONDENSATION 1.Hand pressure condensation Used as first step in 2 step condensation as Initial confinement of material within the cavity, Compaction method is similar to amalgam condensation except force and duration of force is more The condensation energy produced by this method is not always sufficient to fulfill the objectives of the condensation however it can be used simply to effect the initial confinement of the material within the cavity preparation. Dr.MadhuBilla

72. AUTOMATIC HAND CONDENSER This is a spring loaded instrument Blows are delivered by releasing a spiral spring Its main advantage is it gives a series of well regulated blows Disadvantage: blow descends before full pressure is applied Dr.MadhuBilla

73. CONDENSATION BY HAND MALLEATING One of the oldest, preferred by most clinicians Requires trained assistant Correct form of hand malleting : requires light force , bouncing application of mallet to condenser rather then delivering heavy blows (blow must be carefully adjusted it must not be too strong or too heavy,), mallet must travel parallel to central axis of Handle of condenser Advantage: greater control of malleting force, varying force are used, rapid change of condenser tip. Dr.MadhuBilla

74. CONDENSATION BY MECHANICANAL MEANS consist of condenser with working tip and short shank (<1 inch ) with fits into malleting hand piece (either straight or right angled hand pies) Advantage: frequency and intensity of blow can be controlled reduced fatigue Types: a.Pneumatic condensation- Hollen back b . electronic condensation- Mc Shirley Dr.MadhuBilla

75. A.PNEUMATIC CONDENSATION Developed by Dr George. M Hollen back Consist of electric engine and air condenser, air is carried through thin tube to hand piece Condenser vibrates which is energized by compressed air Number of blows -360 /min Advantage: blow does not fall until pressure is placed on condenser point and continues until released Dr.MadhuBilla

76. B. ELECTRONIC CONDENSATION : Developed by Mc Shirley Most efficient and controlled way of condensation Vibrating condenser head - intensity and amplitude is 20 to 15lbs and frequency of blow is 360- 3600 cycles/min Dr.MadhuBilla

77. General steps for insertion of DFG into tooth preparation A . Three steps building up for the restoration Tie formation – is connecting two opposite point angles with a transverse bar of gold. This ‘tie’ forms the foundation of any direct gold Banking of walls – covering each wall from its floor ,Or axial wall to cavosurface margin with direct gold. The wall is banked without obstructing tie formation or banking of other walls. It is done simultaneously on other walls too. Shoulder formation – to complete a build up, two opposing walls are connected with direct gold Dr.MadhuBilla

78. B . Paving of the restoration Every area of cavosurface margin is individually covered with excess gold foil . Condensation from center to periphery is better than periphery to center, since it decrease the trapped air bubbles C . Surface hardening of restoration Utilizes the high condensation energy in the restorative procedure, so as to strain harden the surface gold and fulfill the objectives of restoration Dr.MadhuBilla

79. FINISHING Proper finishing might more aptly be described as additional condensation . Despite the most careful precautions, a condensed mass of gold will be having minute air pockets incorporated into it. When polishing these voids spaces are exposed leaving tiny pits that may not be readily discernible until after the final finish . Finishing consist of following three operations 1. removing of excess gold 2.elimanating pits on the surface 3.polishing the surface. Dr.MadhuBilla

80. 1.Removal of gold – with the use of various rotary instruments such as disks and finishing burs 2.Elimanating pits on the surface- with the use of burnishing hand instruments including gold files, discoid carvers and gold knives, beaver tail burnisher 3.Polishing the surface- with the use of fine garnet and cuttle disks, abrasive strips, pumice and powdered chalk. Dr.MadhuBilla

81. CAVITY PREPARATION FOR DIRECT GOLD RESTORATION Dr.MadhuBilla

82. Class I cavity preparation Dr.MadhuBilla

83. SIMPLE CLASS-I DESIGN I. General shape The outline is similar to class I cavity preparations for amalgam, but with three modifications: A. Instead of rounded corners in the triangular and linear fossa areas, these preps have angular corners. B. The extensions in the facial and lingual grooves in molars will end in a spear-like form, i.e., A pointed termination, rather than rounded. C. The sweeping curves of the outline form of the cavity preparation compared to those for amalgam are less pronounced. In other words, the whole outline will look more angular than in preparation for amalgam. Dr.MadhuBilla

84. 2. Location of margins The facial and lingual margins of these preparations will be on the inclined planes of the corresponding cusps or marginal ridges, so that the width of the cavity will not exceed 1/5th the intercuspal distance. The mesial and distal margins will also be conservatively located on the inclined planes of the corresponding ridge, very close to the adjacent pits. Dr.MadhuBilla

85. Internal anatomy: The mesiodistal and facio lingual cross section of cavity preparations are very similar to those found in amalgam class-I with two exceptions The line and point angles are definite and very angular within dentin substance The cavosurface margins should be beveled with a partial enamel bevel this should be 45º to the direction of enamel rods. Dr.MadhuBilla

86. Complex class-I cavity preparations: T hese are class-I cavity preparations w ith facial and/or lingual extensions. They will have the same general shape, occlusally , as the simple design. The facial and/or lingual extensions will be parallelogram shape. The location of margins is exactly as in the preparation for amalgam, except the mesio distal width of the facial and lingual portions of the cavity preparation should be very limited (1 mm, if possible). The internal anatomy of these cavities will also be similar to the simple design in their occlusal part. However, it is necessary to have starting points At the mesial and distal axio gingival corners of the facial and lingual extensions And again a partial enamel bevel is mandatory Dr.MadhuBilla

87. Pulpal floor - 0.5mm into dentin Undercuts if desired are placed facially and lingually in posterior teeth, and incisally and gingivally on lingual surface of incisors. Cavosurface bevel- 30-40 degree metal at margin for ease of burnishing the gold Bevel - 0.2mm in width Dr.MadhuBilla

88. Class II cavity preparation Dr.MadhuBilla

89. Class-II cavity preparation: CONVENTIONAL DESIGN General shape: The occlusal outline is an exact replica of the simple Class I cavity preparation in molars and premolars, The isthmus portion will definitely have a reversé S-shaped outline facially and lingually due to the very narrow occlusal preparation in transition to a regular size contact area. The proximal portion outline will be a one-sided inverted truncated cone. On the upper teeth, truncation will be at the expense of the lingual proximal wall, and on the lower teeth, truncation will he at the expense of the buccal proximal wall. In other words, the inverted truncation is at the expense of the functional cusp side. Dr.MadhuBilla

90. Location of margins The occlusal portion will have its margins exactly in the same location as the simple Clãss I on the occlusal surfaces of molars and premolars. However, there is no need for ‘dove tailing” in locating those margins. The isthmus portion will have its margins located on the inclined planes of the remaining parts of the marginal ridge and the adjacent cusps, so that the width of the cavity will not exceed 1/5th the intercuspal distance. The margins gingivally will just clear the contact area. There should not be any effort to put the margins subgingivally . Dr.MadhuBilla

91. Internal anatomy A. A mesio -distal cross-section enables visualization of the proximal, pulpal. Axial, and gingival walls and floors. They can be seen to have the same angulation as in class II, design I for amalgam. With two exceptions: I. All line angles, with the exception of the axio -pulpal, will be very sharp. Ii. The cavosurface margins are bevelled at almost 45° to the plane of the enamel walls. B. The facio -lingual cross-section at the gingival one-third indicates that the axial wall will be convex, following the curvature of the proximal surface. Dr.MadhuBilla

92. THE CONSERVATIVE DESIGN: The general shape and location of margins are similar to that of amalgam preparations. Internal anatomy Mesio -distal cross section: This section shows a very slanted axial wall, formed of dentin and enamel. The enamel portion is partially beveled towards the occlusal. The gingival floor is in four planes: an internal, reverse-bevel plane, making an acute angle with the axial wall and formed completely of dentin; a transitional plane, formed completely of dentin and slightly flat: an outer, enamel dentinal plane following the direction of the enamel rods and, finally, a partial bevel on enamel only, not to include more than 1/4th of its extent. Dr.MadhuBilla

93. b. Facio -lingual section: T he triangular areas, facially and lingually , will extend to just short of the occlusal enamel, leaving a limited thickness of dentin to support the occlusal enamel. The triangular area joins the reverse bevel internally via a rounded junction. Dr.MadhuBilla

94. SIMPLE DESIGN General shape: Similar to that of amalgam except that it has a more angular junction between the different margins Location of margins As the whole surface is self clensible the margins can be placed anywhere on the surface. Internal anatomy: a. An occluso -gingival cross-section will show that the occlusal wall is formed of three planes, one plane in the form of dentin, and at right angle to the axial wall; a second plane inclining occlusal proximally, and formed of enamel and dentin; and a third one in the enamel wall, in the form of a bevel. Dr.MadhuBilla

95. B. In a facio -lingual cross-section the axial wall will appear to be flat to slightly rounded. The facial and lingual walls will have the same a natomy If the facial and lingual margins are in the middle third of the proximal surfaces of the corresponding walls two internal planes can be combined into one, following the direction of the enamel rods. Dr.MadhuBilla

96. Class V cavity preparation: Ferrier design Outline -trapezoidal Gingival wall and occlusal wall are flat and parallel to occlusal plane Occlusal wall is longer than gingival Mesial and distal walls makes an obtuse angle with the gingival wall and an acute angle with the occlusal wall Dr.MadhuBilla

97. Mesiodistally axial wall c an be curved so as to prevent encroachment on the pulp But excessive curvature results in preparation which is too shallow in centre or too deep proximally. Axial wall is 1mm deep occlusally and as it comes down cervically , its 0.75mm Mesioaxial and distoaxial line angles are obtuse so as to prevent any undermined enamel and also gives resistance to movement of gold during compaction. Dr.MadhuBilla

98. The mesial and distal walls provide resistance for gold compaction, but they don’t give retention. Retention is provided by sloping of the gingival wall internally to meet axial wall in a sharp defined acute axio gingival line angle . Retention so is achieved by facial convergence of occlusal and gingival walls. Where gingival margin is on enamel, cavosurface is beveled , when it is on cementum, its not beveled Hoe is used for planning the restoration walls and giving sharp internal line angles Dr.MadhuBilla

99. According to the caries extent, different designs of Class-V preparation can be made . Semilunar shaped cavity Class V with uni or bilateral mustache extension Parallelogram in design Class V with proximal pen handle extension Dr.MadhuBilla

100. FERRIER DESIGN PEN HANDLE EXTENSION UNI & BI LATERAL MOUSTACHE EXTENSION CRESENT MOON SHAPED Dr.MadhuBilla

101. CLASS-III CAVITY PREPARATION There are three basic designs for class-III preparations: The F errier design The L oma linda design The I ngraham design Dr.MadhuBilla

102. THE FERRIER DESIGN It is indicated if after removal of all the diseased and undermined tooth structure, bulky labial, lingual,and incisal walls remain Furthermore it is indicated if the labial extension of the lesion f acilitates minimal extension of cavity preparation labially . General shape: Its outline is triangular in shape involving about 2/3 rd ’s to one half of the proximal surface LOCATION OF MARGINS: Being a labial and lingual cavity the labial and lingual margins should be within corresponding embrasures Dr.MadhuBilla

103. Internal anatomy: In labiolingual cross section it can be seen that the axial wall is rounded but not following the convexity of proximal surface. In the inciso gingival cross section the incisal wall appears as in class v cavity preparation i.e. Formed of three or four planes All the line angles and point angles should be sharp with exception of junction between the line angles of the cavity preparation proper and those of retention forms which should have a rounded junctional relationship. Dr.MadhuBilla

104. INSTRUMENTATION No 33 ½ bur or suitable Wedelstaedt chisel –used from facial aspect to position the gingival outline and the facial wall. Planning the labial wall and incisal out line with wedelstaedt chisel Planing the incisal wall with angle former Dr.MadhuBilla

105. Establishing the lingual wall with wedelstaedt chisel Removal of the linguogingival bulk with inverted cone bur (33½) Planing the the gingival wall and labial wall to establish the résistance form using 6 ½-2 ½ -9 ½ hoe Dr.MadhuBilla

106. Hoe is used to planning the lingual wall and sharpening linguogingival line angle and linguogingivoaxial point angle Axial wall is planed with hoe to give convex surface Dr.MadhuBilla

107. Small angle former- complete the sharp point angles and acute axiogingival angle Bibeveled hatchet (3-2-28)-establish the incisal retentive angle with chopping motion Dr.MadhuBilla

108. LOMA-LINDA DESIGN: This design is indicated for a combination of powdered gold build-up with a cohesive gold foil veneer. It is used when access to the lesion is lingual, as dictated by esthetics and the caries extent, or when the lingual marginal ridge is lost or undermined. General shape: The proximal part of this cavity design will be triangular with rounded corners. The lingual part may have an incisal or gingival “turn” as dictated by access and resistance form Dr.MadhuBilla

109. Location of margins: Gingival margins of the Loma-Linda preparation are similar to the Ferrier design. Labial margins, in some situations, may be located in the contact area, making the restoration completely inconspicuous. However, the labial margin will usually have the same locations and specifications as in the Ferrier design. The lingual margin will be located far enough onto the lingual surface to include the marginal ridge and to facilitate access to the internal parts of the cavity preparation. Dr.MadhuBilla

110. Internal anatomy: I nciso -gingival cross-section: The loma-linda design appears to have the same anatomy as the incisal gingival section of the ferrier design, except the line and point angles are more rounded. Also, the incisal internal retention mode appears bulkier than in the ferrier design. Labio -lingual cross-section: if the labial margin is located in the contact area. The labial wall will be formed of two planes: an enamelo -dentinal plane at right angle to the axial wall following the directions of the enamel rods and a partial enamel bevel plane. Dr.MadhuBilla

111. The point angles gingivally accommodate two cylindrical retention grooves. They will be directed labio - gingivo -axially and linguo - gingivo -axially extending about 1.5-2 mm into the dentin. The incisal retention mode is directed inciso - labio -axial and is cylindrical in form. Dr.MadhuBilla

112. INGRAHAM DESIGN This preparation design is indicated primarily for incipient proximal lesions in anterior teeth where esthetics is the main concern. After removal of diseased and undermined tooth structure, this preparation design will accommodate bulky gingival and incisal walls. Good oral hygiene, low caries and plaque indices are essential indications due to the outline of this design. Dr.MadhuBilla

113. General shape: This preparation is a simple parallelogram in shape. Location of margins: The labial margin of the ingraham design will be in the contact area, so it is truly invisible labially . The gingival margin just clears the contact area in the gingival embrasure without any predetermined relationship to the gingiva. The incisal margin will be within the contact area. The lingual margin will be on the lingual surface past the marginal ridge, and/or axial angle of the tooth. Dr.MadhuBilla

114. INTERNAL ANATOMY: INCISO-GINGIVAL CROSSSECTION: A t the very labial one-third of the cavity the gingival wall will have three planes. An internal dentinal plane, part of a wall accommodating triangular retention mode, and, inclining apically. A n outer enamelo -dentinal plane following the direction of the enamel rods; and a peripheral partial enamel plane bevel. the axial wall will appear to be perfectly flat. the incisal wall will have the same anatomy as the gingival wall, but in the reverse direction. Labio -lingual crosssection: The axial wall appears perfectly flat, opening directly to the lingual surface and making a right angle with the labial wall. Dr.MadhuBilla

115. High quality direct-gold restorations can be ensured only when four principal conditions are satisfied: The appropriate gold form is used for each specific clinical situation. The material is used only where it is indicated. A perfectly dry and clean field is provided. The material is properly manipulated with the correct instruments. Philips Textbook of dental materials 11 th ed Dr.MadhuBilla

116. CONCLUSION The option to utilize gold foil as the best restoration totally rests on the shoulder of the operator . Unless a conservative dentist takes a conscious attempt to learn and master this wonderful material and technique for many indicated lesions, the patient will be deprived of the very best treatment because of the fallacy of the conservative dentist . Dr.MadhuBilla

117. REFERENCES Operative dentistry –(modern theory and practice) – m.a . marzouk Science of dental materials-(11 th edition)- phillips and kenneth William Obrein - 3 rd edition Operative dentistry (3 rd edition) – genard t. charbeneaw Operative dentistry (3 rd edition )- baum , phillips and lund Sturdvents operative dentistry 5 th edition. Dr.MadhuBilla

118. SMITH B J OF SOTH CALIFORNIA STATE DENTAL ASSC. 1959 Advantages of direct gold filling by L.Clarke Operative dentistry 1985 10-22 Stopfgold : a new direct filling gold. Lambert RL; [ Oper Dent] 1994 Jan-Feb; Vol. 19 (1), p. 16-9 . EZ-Gold The New Goldent By Alperstein , Yearwood Jod 1996,21, 36-41 Dr.MadhuBilla

119. THANK YOU….. Dr.MadhuBilla