DIRECT FILLING GOLD

History of Direct filling gold
Properties of gold
Indications, contraindications, advantages and disadvantages of direct filling gold, cohesive semi cohesive and non - cohesive gold, types of direct filling gold, Degassing/ Annealing, steps for insertion of dfg, cavity preparation and restoration of direct filling gold

1. DIRECT FILLING GOLD

2. CONTENTS INTRODUCTION HISTORY PROPERTIES OF GOLD INDICATIONS CONTRAINDICATIONS ADVANTAGES DISADVANTAGES COHESIVE, SEMI – COHESIVE AND NON – COHESIVE GOLD

3. TYPES OF DIRECT FILLING GOLD DEGASSING/ ANNEALING GENERAL STEPS FOR INSERTION INTO TOOTH PREPARATION CAVITY PREPARATION AND RESTORATION OF DIRECT FILLING GOLD CONCLUSION REFERENCES

4. INTRODUCTION Among the available restorative materials, direct filling gold is the oldest filling material The vision to utilize the noble metals for the replacement of lost tooth structure stemmed from perfect harmony of its biological and mechanical properties . The use of gold in restorations remains considerable today, however, with an increasingly wide range of alternative materials available in dentistry, there is choice for a replacement of older and discolored fillings . .

5. HISTORY First evidence GREEK and ROMAN culture about 3000 B.C Sumerian, babylonian , assyrian tombs between 2000 and 3000 B.C 1483- Giovanni d A rcoli first recommended gold leaf filling as restorative material in dentistry 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

6. 1838 - Dr .E. Meritt of pittsburg introduced hand mallet for compaction. 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

7. 1964 - Goldent powdered gold was introduced 196 9 – R. V . W illa m s and C.In g ers o il i n tr o d u c e d Electralloy 1980- E-Z gold were introduced by Baum 1989 - New granular type of gold was introduced by Dhiek and Regelstein

8. PROPERTIES Atomic number – 79 Atomic weight – 196.966amu Soft, malleable ,ductile with percentage elongation of 12.8 %. Malleating produces sheets as thin as 0.13mm Rich yellow in colour with strong metallic lustre . Cohesiveness depends on purity of gold. Max cohesiveness at 999 fine The best gold for restorations is about 999 parts in 1000 pure gold.

9. Melting point 1063 Boiling point 2200 True density 19.3 gm/cm 3 . Apparent density range 14-15 gm/cm 3. Brinnels hardness number 25 . Cold working while building the restoration increases its hardness to almost 58-82. C.T.E is 14.4 x 10 -6 / c High thermal conductivity of 0.710 cal /sec/cm 2 (/ C/cm) Noblest of all metals. No tarnish or corrosion .

10. Small amount of impurities affect mechanical properties. 0.2% lead makes gold very brittle. Ca, Pl, Pt improves the properties. The most important property of pure gold is the ability to be cold welded or welded at room temprature . If two pieces of gold are pressed firmly together and sufficient force is applied they unite at that point of contact without applying heat, Cold welding property . DFG ‘s most efficient sealing permanent fillings .

11. INDICATIONS For Restoration of Tooth Preparations Direct filling gold restorations are indicated for incipient or early lesions, small in size present in non stress bearing areas. These may include: Small Class I preparations of all teeth Class II preparations with minimal proximal caries of premolars and on mesial surface of molars Class III preparations of all teeth specially when aesthetics is not important. Class V preparations of all teeth

12. Class VI preparations of teeth where high occlusal stress is not present Erosion: Direct filling gold restoration are done for small erosions on all the surfaces of premolars, canines and incisors where aesthetics concern is limited. To Repair Margins: It is used to repair endodontic openings in gold crowns or for gold crown margins, onlays and inlays. For Hypoplastic Defect: Direct filling gold is used for hypoplastic or other defects on the facial or lingual areas

13. CONTRAINDICATIONS Direct gold fillings are contraindicated in the following conditions: Young Patients: It is not desirable to do direct filling gold restoration for aesthetic reasons and due to high pulp horns. Limited Accessibility: It makes the manipulation of gold difficult so defies its use Size of the Lesion : If large amount of tooth is destroyed, it is not indicated to use direct filling gold

14. Poor Periodontal Condition : In patients suffering from pyorrhea to the degree that they have lost considerable of the alveolar process and not indicated. Temperament of Patient : Some nervous patients are unable to tolerate the continuous blow of the mallet, direct filling gold restoration should not be used in them. Handicapped Patient: Since these restorations are time consuming, they should not be used in such patients

15. Aesthetics: If aesthetics is of prime importance, direct filling gold is not indicated. Heavy Occlusal Stresses: Since gold cannot withstand heavy occlusal forces, it should be avoided in stress bearing areas Prognosis of the Tooth: It should not be used when expected functional period of the tooth is not more than two years.

16. ADVANTAGES Insoluble in oral fluids More resistant to tarnish and corrosion The resilience of dentin and the adaptability of gold allow an almost perfect seal between the tooth structure and gold. More edge strength Low tendency to molecular change (free from shrinkage or expansion) as CTE is similar to dentin Maintain high polish Long lasting, if properly placed

17. Malleability of gold makes it possible to add gold in very small amounts that are building up the filling. Malleability also provides permanent self sealing margins. No intra cement substance needed Oral tissue accepts readily Causes no tooth discoloration because of good adaptation to the preparation margins and walls. Gold can withstand compressive forces even in thin layers, hence deeper tooth preparation is not required

18. DISADVANTAGES These restorations are technique sensitive, and to achieve excellence, great skill, patience and time is required. Improper placement of gold foil can damage the pulp or periodontal tissues. The welding technique, with or without a mallet, can do pulpal trauma. Because of the high thermal conductivity of gold, larger restoration can increase sensitivity

19. A larger restoration is very difficult to finish and polish. Gold foil is more expensive than any other restoration material. Multiple restorations are hectic because it is time consuming. It cannot be placed where aesthetics is required Gold is indicated only when the lesion is small in size present in non stress bearing areas.

20. If gold and amalgam fillings are right next to each other, “galvanic shock” can occur. It happens when interactions between the metals and saliva result in electric current, this can cause discomfort to patient. Manipulation of gold is difficult to master. It requires skill and practice

21. COHESIVE GOLD NON - COHESIVE GOLD SEMI - COHESIVE GOLD

22. 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 in type - cohesive foil.

23. 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.

24. NON – COHESIVE GOLD Non vola t ile cont a m inan t s l i ke i r on, sulphu r , phosphor ous a r e 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.

25. Types of Direct Filling Gold 1. Gold foil Sheets Gold foil cylinder Gold pellets Platinized gold foil Corrugated foil Laminated foil

26. 2. Crystalline gold or electrolytic precipitated Mat gold Mat foil Electralloy 3. Powdered gold/ Granulated gold 4. E-Z Gold 5.Stop gold

27. GOLD FOIL Also called fibrous gold . Available as sheets , pellets , cylinders , ropes and pre-condensed laminates of varying thickness. Gold leaf used in ornamentation , is about 0.1 μm thick. Dental foil (the usual No 4) is six times thicker, in other words 0.6 μm .

28. GOLD FOIL SHEETS 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 For rolling, it is passed through rolling mills until desired thickness is got.

29. The gold foil is made by beating pure gold into thin sheets of size 10 × 10 cm (4 × 4 inch) The foils are supplied in books which are separated by thin paper pages. Each book has approximately twelve gold foils. Since size of 4 × 4 inch foil is too large for its use in preparation. Before insertion into the tooth preparation, it is cut, rolled into ropes, cylinders or pellet.

30. The book is divided into such sizes that represent 1/2, 1/4,1/8, 1/16, 1/32, 1/64 and 1/128 of a sheet of gold that weighs 4 grains N o . 4 g o ld foil weig h s 4 grains ( 0. 2 5 9 g m ) and is 0. 5 1 µm thick No. 3 gold foil weighs 3 grains (0.194gm) and is about 0.38µm thick

31. GOLD PELLETS They can be mechanical or handmade 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

32. 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 The rolled pellets can be stored in a gold foil box along with a cotton dipped in 18 percent ammonia

33. GOLD CYLINDERS Gold cylinders commonly used are of 1/4 and 1/8 of a sheet of gold. Cylinders of non-cohesive gold are used in the non-cohesive state and never annealed for cohesive use Can be hand rolled or commercially rolled

34. Made by rolling the cut segment of No. 4 foil into 1/2, 1/4, 1/8 widths O ne end of the ribbon is held with an instrument and rolled again and again until the other end is reached

35. CORRUGATED/ CARBONIZED GOLD FOIL This 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.

36. Gold foil remains unharmed except it becomes corrugated because of the shriveling of the paper It has been proven that corrugated gold foils are more cohesive than the plain ones . Gold with superior welding property

37. PLATINIZED GOLD FOIL This type of foil is made up by sandwiching a sheet of platinum between two sheets of gold foil and then hammered until a final platinized gold is formed. Layers o f gold and p la t inum are r o l led o v er t oget h er so t hat t her e occurs fusion of the two even before the beating procedure begins. The platinum content in foil is 15%. Purpose of adding platinum to gold is to increase the hardness and wear resistance of the restoration. This makes its use in areas of high occlusal stress like cusp tips and incisal edge of anterior teeth.

38. LAMINATED GOLD FOIL When a cube of gold ingot is cold worked in order to formulate a sheet, the cubical crystals of gold will be 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. 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.

39. 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.

40. ELECTOLYTIC PRECIPITATED GOLD This consist of the crystalline gold powder formed by electrolytic precipitation. The powder is formed into different shapes by heating at a temperature well below the melting point of gold. Diffusion of the particles occur at the point of contact so that the particles coalesce and grow. Mat gold Mat foil Gold calcium alloy

41. MAT GOLD/CRYSTAL GOLD In 1937, Rule first referred to crystal gold in his analysis of gold foil. It is an electrolytically precipitated crystalline form that is sandwiched between sheets of gold foil These are available in the form of strips of medium widths (2.0mm)and wide widths(3.0mm)which can be cut to the size that fits the cavity. These material has a spongy structure with loosely arranged or fern like crystals. During subsequent heating process , branch ends of the crystals are rounded and tend to weld themselves together.

42. 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. As it is loosely packed it is friable and contain numerous void spaces between the particles (large surface area) - therefore it does not permit easy welding into a solid mass as does gold foil. So it is recommended for the external surface of the restoration

43. ADVANTAGES DISADVANTAGES

44. 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 differs from the so-called cohesive type foils .

45. 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. I t s m echan i cal st rength is the re sult of a spec i al m old i ng and heat treatment process. The ideas to use mat foil was to eliminate the need to veneer the restoration with a layer of gold foil

46. ALLOYED ELECTROLYTIC PRECIPITATE / GOLD- CALCIUM ALLOY 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

47. ELECTRALLOY RV This is a mat gold manufactured by Williams Gold Refining Company, New York. R.V stands for R.V. Williams who developed this

48. POWDERED GOLD Powdered gold is in the form of minute particles . It can be obtained by atomization from a molten state or by chemical precipitation . In the latter process, gold is dissolved in aquaregia (mixture of Nitric acid and Hydrochloric acid in 1:3 molar ratio) and precipitated by oxalic acid , sulphur dioxide or sodium nitrate . The average particle size is 15µ.

49. As a powder the material is impractical to manipulate ,so is gathered into a conglomerate mass having a diameter of 1-3mms These masses are either sintered or lightly precondensed to facilitate slight adhesion between the particles and ease handling . However ,even on mild provocation ,these masses tend to fall apart . Because powder gold produces a less porous surface compared to mat gold, veneering with a gold foil is not very much necessary.

50. Powdered gold and gold foil combination Introduced in 1962 by Baum & Lund. Commercially available as pellets of powdered gold wrapped in a gold foil know as “ Goldent ”. Powdered particles are mixed with a soft wax and held in no.3 gold foil. The ratio is 95% powder and 5% foil Gold foil acts as container for powdered particles & facilitate their condensation.

51. Each pellet is approximately 10 times more gold than a pellet of gold of comparable size. Hand compaction better thn mechanical compaction for powdered gold

52. 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 E-Z GOLD

53. M etallurgically 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

54. Stopfgold : A new direct filling gold, 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

55. DEGASSING/ANNEALING DEGASSING - Process of heating direct gold materials to remove the surface contaminants. Achieved by - Heating the gold foil over pure ethanol flame. - Heating in a mica tray mounted over an alcohol lamp - Heating in a electric annealer Operative dentistry –(modern theory and practice) –Marzouk

56. 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 which results in metallic bonding

57. Heating on alcohol flame Heating on alcohol flame can be done in two ways: a. Bulk method b. Piece method. In bulk method , e n masse gold is placed on the mica tray and then heated over open gas or alcohol flame. The tray is heated until the gold pellets achieve the temperature of 650-700ºC.

58. The advantages of bulk method are: Takes less time Degassing of several gold pellets at the same time is possible Convenient The disadvantages of bulk method are: • Sticking of gold pieces • Unused gold may be left and it can be wasted due to contamination. • Risk of overheating.

59. In piece method Heating unit used is open flame Absolute or 90% ethyl / methyl alcohol without any additives used to produce a clean blue flame Gold is carried and held with Nichrome wire because it does not interfere with cleaning process Gold is then passed over the blue flame for 3-5 sec Temperature of the flame is about 1300°F . The heating is done until the gold becomes a dull red.

60. Advantages of piece method: • Less wastage • Desired size of piece can be selected. Disadvantage of piece method: • Time consuming

61. Electric annealer This is the most controlled and standardized way of decontaminating gold materials, 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.

62. Electric annealing is maintained at temperature 640 F is 5 minutes Heating time depend on size and configuration of gold segment (powdered gold-15-20 sec, gold foil pellet, electrolytic gold -1-2 sec) One must take care to prevent overheating or the underheating as both of these can hamper qualities of gold.

63. Advantage Convenient method Disadvantage Overheating leads to strain hardening Air current affect heat uniformity

64. 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. Done simultaneously on other walls too. Shoulder formation – to complete a build up, two opposing walls are connected with direct gold General steps for insertion of DFG into the tooth preparation

65. B. Paving of the restoration Every area of cavosurface margin is individually covered with excess gold foil . Foot condenser is useful C. Surface hardening of restoration Utilizes the high condensation energy in the restorative procedure To strain harden the surface gold and fulfill the objectives of restoration

66. 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. CONDENSATION/COMPACTION Operative dentistry –(modern theory and practice) –Marzouk

67. Objectives of condensation: Wedge initial pieces between dentinal walls, esp at starting point. Weld the gold pieces together by complete cohesion of the space lattice. To minimize voids Strain hardening of gold materials which is due to cold working during condensation. Adapt material to cavity walls and floor Elastically deform the dentin of the cavity walls and floors

68. CONDENSERS Condensers are used to deliver forces of compaction to DFG Condenser can be used with hand pressure and mechanical malleting Parts: shank, nib (working end) CONDENSER NIB faces are serrated with pyramidal shape configuration to prevent slipping of gold

69. Types of Condensers based on Shapes of nib: Round condenser 0.4 to 0.55mm diameter, Used in initial stage of restoration. Parallelogram condenser nib face measures 0.5x1mm Used only for hand pressure compaction Used to create the bulk of the restoration

70. Foot condensers nib face rectangular-1 x1.3mm Used mainly for cavosurface condensation as well as bulk build up

71. CONDENSOR SHANK Available as : straight , monoangle, offset, binangle Condenser used for hand malleting have longer shank, than condensors used in other mechanical means.

72. CONDENSER ANGULATION Sturdevent , 5 th edition

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

74. HAND PRESSURE CONDENSATION Use of hand pressure alone is contraindicated. Used as first step in condensation as Initial confinement of material within the cavity. used for anchoring gold in point Or convenience angles Small diameter .5mm without greater pressure used Condenser with hand mallet are longer (6 inches), and have a blunt ended handle (15cm in length) receives light blows from hand mallet Operative dentistry –(modern theory and practice) –Marzouk

75. CONDENSATION BY HAND MALLET 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

76. AUTOMATIC HAND CONDENSER This is a spring loaded instrument Blows are delivered by releasing a spiral spring Advantage - it gives a series of well regulated blows Disadvantage: blow descends before full pressure is applied

77. MECHANICANAL CONDENSATION Consist of condenser with working tip and short shank (<1 inch ) with fits into malleting hand piece (either straight or right angled hand pieces) Advantage: frequency and intensity of blow can be controlled Types: a.Pneumatic condensation - Hollen back b. Electronic conden s atio n - Mc S h irley

78. PNEUMATIC CONDENSATION Consist of electric engine and air condenser, air is carried through thin tube to hand piece Speed of engine regulated by rheostat button 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

79. ELECTRONIC CONDENSATION Most efficient and controlled way of condensation Vibrating condenser head - intensity is 20 to 15 pounds and frequency of blow is 360- 3600 cycles/min Designed to lessen the strain of operator and patient

80. PRINCIPLES OF CONDENSATION 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

81. Forces of condensation must be directed at 90 degrees to previously condensed gold 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

82. 4 . U se 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

83. E. Margination Using sharp instruments, moving from gold to tooth surface This step eliminates excess in small increments Done until possible to visualize original outline of preparation D. Burnishing From gold to tooth Adapt gold more and hence eliminate voids Specially designed Spratley burnisher is moved with pressure over restoration to close the voids. This also enhances surface hardness of the restoration .

84. F. Final Burnishing Follows margination to ensure closure of marginal voids and surface discrepancies G. Contouring Creating proper anatomy of restoration to coincide with opposing, contacting, occluding tooth. Done using knives, files, finishing burs Contouring involves margins, should be re burnished before final contouring

85. H. Finishing and polishing Minimal finishing required for properly marginated, contoured restoration Finishing done using precipitated chalk and tin oxide powder or rubber cups Fine garnet and cuttle disks are moved from gold towards tooth surface for final finishing. For polishing, silica, pumice or metallic oxide compounds can be used. For final polish, a satin finish is preferable to a high gloss. Advantages Polished restorations do not tarnish or corrode in oral fluids. They promote the health of the gingival tissue which is in contact with the restoration. Polished restoration minimizes reflection of the light rays and creates a more esthetic and harmonious end result.

86. CAVITY PREPARATION FOR DIRECT GOLD RESTORATION Operative dentistry –(modern theory and practice) –Marzouk SIMPLE CLASS-I DESIGN General shape The outline is similar to class I cavity preparations for amalgam, but with three modifications: Instead of rounded corners in the triangular and linear fossa areas, these have angular corners. 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. angular outline form of the cavity

87. Outline form is kept as conservative as possible. It involves removal of all carious fissures and extending them to the point of immunity. Depth of cavity should be 0.5 mm into dentin. External walls of the preparation must be parallel to each other. If additional retention is required, undercuts are placed in facial and lingual walls by small inverted cone bur.

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

89. Internal anatomy The faciolingual and mesiodistal cross section of cavity preparations shows 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.

90. Simple class I cavity preparation In case of Lingual surface of upper anterior teeth Facial and lingual pit of upper and lower molar Shape triangular with base facing gingival Location of margins – anywhere, self cleansible

91. COMPLEX CLASS-I CAVITY PREPARATIONS Class-I cavity preparations with facial and/or lingual extensions. Same general shape, occlusally The facial and/or lingual extensions will be parallelogram shape. L ocation of margins Mesio distal width of the facial and lingual portions of the cavity preparation is limited (1 mm ,if posssible ) Partial enamel bevel is mandatory

92. CLASS I CAVITY PREPARATION/RESTORATION Use smaller burs 330/329 bur For final shaping angle former to sharpen internal anatomy Partial enamel bevel- wedelstaedt chisel Final finishing-7802/ flame shaped white stone

93. Begin restoration by wedging small piece gold foil between point angles using rounded hand condenser Hold it using gold foil holder using distobuccal pulpal pressure Pick up small pellet of cohesive gold foil and insert into cavity Always condense towards same point angle till 2/3 distopulpal line angle covers Create tie from point to point angle ( distopulpal to mesiopulpal PA) Bank distal part buccal and lingual portion Make tie along buccopulpal line angle Bank the buccal wall and half mesial wall Make mesial tie and bank rest of mesial lingual wall

94. The concavity at the center will be filled with foot condenser Burnish(beaver tail burnisher) from gold to tooth and carve using cleoid carver Polishing using rubber cups

95. CLASS-II CAVITY PREPARATION CONVENTIONAL DESIGN General shape: The occlusal outline similar to simple Class I cavity preparation The isthmus portion- reverse S-shaped outline facially and lingually due to the very narrow occlusal preparation in transition to a regular size contact area. Deep pits and fissures which are separated by atleast 1mm thick healthy dentin are restored as separate preparations Buccal and lingual walls should be extended to contact area but breaking of contact is not required as in case of amalgam restoration

96. The proximal portion outline will be a one-sided inverted truncated cone. Inverted truncation is at the expense of the functional cusp side. On the upper teeth, truncation- lingual proximal wall On the lower teeth, truncation- buccal proximal wall.

97. Location of margins The occlusal portion similar to class 1 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 The width of the cavity will not exceed 1/5th the intercuspal distance. The margins gingivally will just clear the contact area. No effort to put the margins subgingivally

98. Internal anatomy All line angles, with the exception of the axio -pulpal, will be very sharp. 2. The cavosurface margins are bevelled at almost 45° to the plane of the enamel walls.

99. In facio lingual cross section Gingival one-third axial wall is convex facial and lingual wall has 4 planes 1.inner dentinal plane making acute angle 2.second plane-completely in dentine 3.third-enamel dentinal plane 4 fourth plane-partial bevel in enamel Middle one-third same three walls first plane makes less acute angle

100. At the level of pulpal floor 3 planes Inner dentinal plane outer enamel dentinal plane third plane of partial bevel Occlusal level facial lingual walls in reverse s shape partial bevel on enamel

101. THE CONSERVATIVE CLASS II DESIGN: The depth and width of the cavity depends on the extent of caries Preparation similar to conventional design except that it should be as conservative as possible The enamel portion is partially beveled towards the occlusal.

102. The gingival floor is in four planes: Internal, reverse-bevel plane, making an acute angle with the axial wall, formed completely of dentin Transitional plane, formed completely of dentin outer, enamel dentinal plane following the direction of the enamel rods partial bevel on enamel.

103. SIMPLE DESIGN General shape: This consist of only the affected proximal surface of the tooth without involving the occlusal surface Similar to that of amalgam except that it has a more angular junction between the different margins Partial bevel placed on all walls Location of margins surface is self clensible the margins can be placed anywhere on the surface.

104. Internal anatomy: Occluso -gingival cross-section- Three planes one plane in dentin, at right angle to the axial wall second plane inclining occlusal proximally, formed of enamel and dentin enamel wall- bevel.

105. Facio -lingual cross-section 3 planes - Dentinal plane right angle to axial wall Outer enamel, dentinal plane Partial bevel If access through facial or lingual - Non access wall same access wall have two planes Enamelo-dentinal making obtuse angle with axial wall Partial bevel

106. CLASS II CAVITY RESTORATION Matrix is contoured, adapted proximally Wedge placed proximally Conventional design Ball of goldent is placed over proximal retention groove, another along gingivo axial line angle Continue till whole line angle and opposite retention groove is covered Using Loma Linda condenser rupture balls ,seat the gold by tapping motion Condense gold until reaching pulpal floor

107. Cohere goldfoil to already condensed powdered gold at occlusobucco proximal part Repeat it for banking lingual wall Condense remaining as class 1 Burnish proximal part Use Wilsons knife for gingival overhangs Finishing and polishing

108. CLASS-III CAVITY PREPARATION There are three basic designs for class-III preparations: The Ferrier design The Loma Linda design The Ingraham design

109. THE FERRIER DESIGN Indication After carious removal, if thick labial,lingual,incisal walls are remaining If the labial extension of the lesion facilitates minimal extension of cavity preparation labially. Distal surfaces of anterior teeth General shape Its outline is triangular in shape involving about 2/3 rd ’s to one half of the proximal surface

110. Location of margins: Labial margin should be minimally extended in the labial embrasure Lingual margin should not encroach on marginal ridge (marginal ridge involving Ferrier design contraindicated) Incisal margin is in contact area

111. Internal anatomy: In labiolingual cross section the axial wall is rounded but not following the convexity of proximal surface. labial and lingual wall-Inner dentinal plane right angle to axial wall, outer enamel dentinal plane and peripheral partial enamel bevel

112. Inciso gingival cross section Incisal wall 4 planes Inner dentinal plane ,transition completely of dentin Outer enamelo dentinal plane and partial enamel bevel Gingival wall 4 planes Inner beveled dentinal plane ,transition- completely dentine, enamelo dentine plane and partial bevel

113. Modification for lower incisor Labial extend of cavity should be very limited -very wide and accessible labial embrasure Flat axial wall - minimum convexity of proximal surface and pronounced pulp chamber Lingual & labial wall two planed- perpendicular enamelo dentinal plane to axial wall and partial enamel bevel

114. TOOTH PREPARATION No 33 ½ bur or suitable Wedelstaedt chisel –used from facial aspect to position the gingival outline and the facial wall. Planing the labial wall and incisal out line with wedelstaedt chisel Planing the incisal wall with A ngle former

115. 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 hoe

116. 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 Small angle former- complete the sharp point angles and acute axiogingival line angle Bibeveled hatchet -establish the incisal retentive angle with chopping motion

117. LOMA-LINDA DESIGN: This design is indicated for a combination of powdered gold build-up with a cohesive gold foil veneer. This design is used in cases where: • Lingual marginal ridge is involved • Facial surface has to be preserved • Esthetics is most important. In this method, access is made through lingual approach. . For retention, small grooves are made in three opposite directions 1) Incisal point angle, 2) Linguo gingival DEJ, 3) Facio axio - gingival point angle Sturdevant 5 th ed

118. General shape: The proximal part of this cavity design will be triangular with rounded corners. Location of margins: Gingival margins similar to the Ferrier design. Labial margin will usually have the same locations and specifications as in the Ferrier design. Labial margins, in some situations, may be located in the contact area The lingual margin will be located far enough onto the lingual surface to include the marginal ridge Operative dentistry –(modern theory and practice) –Marzouk

119. Internal anatomy Inciso -gingival cross-section: same anatomy as Ferrier design, except the line and point angles are more rounded Labio-lingual cross-section: The labial wall formed of 2 planes: enamelo -dentinal plane at right angle to the axial wall following the directions of the enamel rods partial enamel bevel plane. Lingual wall 2 planes following the directions of the enamel rods partial enamel bevel plane.

120. INGRAHAM DESIGN This preparation is a simple parallelogram in shape Incipient proximal lesions in anterior teeth where esthetics is the main concern. Preparation design will accommodate bulky gingival and incisal walls. Location of margins: The labial margin in the contact area- invisible labially. The gingival margin just clears the contact area in the gingival embrasure The incisal margin will be within the contact area. The lingual margin will be on the lingual surface past the marginal ridge

121. RESTORATION Condense piece of gold into linguo gingival axial retention point Step wise condensation along gingivo axial line angle Follow same for labial portion Incisal area filled with compacting gold pelllets with right angled hand condenser and offset condenser

122. CLASS IV CAVITY PREPARATION Indications Favorable bite Sufficient thickness of the incisal edge to permit a step. In class IV preparations, an incisal or lingual step is substituted for incisal anchorage which is used in a simple proximal preparation. Gingival wall is same, but may be inclined toward axial wall more acutely. Labial and lingual walls meet the axial wall at right angles.

123. CLASS V CAVITY PREPARATION 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

124. According to the caries extent, different designs of Class-V preparation can be made Ferrier design Pen handle extension Uni & bi lateral moustache extension occlusally Partial moon /Semilunar/crescent shape cavity preparation