Direct fiiling gold conservative dentistry

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1. DIRECT filling gold - MATERIALS Sneha MS ROLLNO 25 3 RD YR IR BATCH

2. Contents Introduction Definition Types of direct gold Properties Manipulation of DFG Degassing Compaction Indication Contraindication Conclusion reference

3. Introduction Pure gold has been in used in dentistry for more than 100 years. It is generally agreed that this noble metal is a superior restorative material for treatment of many small lesions and defects in teeth, given sound pulpal and periodontal health.
The longevity of direct gold restorations is a result of the superb biocompatibility of gold with the oral environment and its excellent marginal integrity.

4. Definition Direct gold is a gold restorative material that is manufactured for compaction directly into prepared cavities .

5. Types of direct filling gold

6. Gold foil Gold foil is also called fibrous gold . It is available as sheets, pellets, cylinders, ropes and pre condensed laminates of varying thickness.

7. A. Gold foil sheets : these are manufactured by beating or rolling pure gold ingots into thin sheets. Gold foil is cut into 4x4” sheets and sold in books Of sheet separated by thin paper. The sheet of foil that weighs 4 grain termed as no 4 Foil 3 grain termed as no 3 foil 2grain termed as no 2 Foil

8. B. Gold foil pellets: th ese may be hand rolled or commercially produced from a no 4 gold foil sheets Small sections of the gold foil sheets (1/32”, 1/64”, 1/128”) are cut and rolled into pellet form.

9. C. Gold foil cylinders : these may also be hand rolled or preformed. Usually larger segments of sheet (1/2”,1/4’, 1/8”) are cut and rolled into cylinders.

10. . D. Corrugated gold foil : It was an outcome of Chicago fire in 1871 these are manufactured by placing thin sheets of paper in between the gold foil sheets and igniting them. The paper burns and gets charred while the gold foil becomes corrugated.

11. E. Platinized gold foil: this is is a sandwich of gold and platinum with the platinum content being 15%. It may be manufacture in one of the following ways.
One sheet of pure platinum foil may be sandwich between 2 sheets of gold. These are then hammered to form a platinized gold foil.

12. Layers of platinum of gold are rolled over together to bring about their fusion following which they are beaten to achieve desired thickness.
Addition of platinum increases the strength and wear resistance of the restoration. Platinized gold foil may be used for areas of stress concentration like incisal edges and cusp tips.

13. F. Laminated gold foil : when gold foil is beaten from an ingot, its crystals are elongated in a specific direction. A combination of two or three foils with crystals running in different direction is called a laminated gold foil.

14. 2. Electrolytic precipitated gold This is a crystalline gold powder formed by electrolytic precipitation.. A.Mat gold: this is a crystalline electrolytically precipitated gold that is formed into strips. This form is easy to use for building the internal bulk of the restoration because of ease of compaction.

15. B. Mat foil: This consists of sandwich of electrolytically precipitated gold powder between two sheets of No. 3 gold foil which is sintered and cut into strips. This purpose of sandwiching mat gold between foil sheets is to eliminated the need to veneer the restoration the layer of foil.

16. C. Gold calcium alloy: this the another form of electrolytically precipitated which is alloyed with 0.1% calcium. It is commercially available as Electralloy RV. The addition of calcium produces a stronger restoration by dispersion strengthening. This is sintered so as to make the gold into strip form.

17. 3.Powdered gold Powdered gold is made by a combination of chemical precipitation and atomization with an average particle size of 15 μ m.
■ Since powders are difficult to manipulate the particles are mixed together in wax and cut in to pieces and wrapped in gold foils as pellets.
■ This is available as Goldent or Williams E-Z Gold.

18. Properties of DFG ■ Pure gold is soft, malleable and ductile and does not oxidize under normal atmospheric conditions.
■ It has a rich yellow color and a strong metallic luster.
• Gold fusses at 1063° c and boils at 2200° с. ■ The Brinell hardness no. for gold is 25 this makes it very soft. However during compaction the hardness increases 258-82 making it a strong material.

19. ■ The coefficient of thermal expansion of gold is 14.4 x 10-6/°C which is close to that of tooth structure(11.4 x 10-6/°C) It can be cold welded at room temperature Gold doesn’t undergo tarnish and corrosion.

20. Principles of Manipulation of DFG There are two processes involved; ■ Cohesion and Degassing

■ compaction

21. 1.COHESION AND DEGASSING Direct gold may be either cohesive or non cohesive COHESIVE GOLD : The gold is considered to be cohesive in nature when its surface is pure and free of surface oxides and impurities. NONCOHESIVE GOLD :it is considered noncohesive in the presence of surface impurities or wax , which prevents one increment of gold from cohering to another

22. 1.Degassing ( annealing) ■Degassing is the process of heating direct gold materials to remove the surface contaminants.

■ It can be 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 .

23. 1 . Heating over an open alcohol flame: In this method each piece of direct gold is held in the middle zone of an alcohol flame for 3-5 sec before inserting into the cavity preparation. 2. Heating in a mica tray over the alcohol flame : This is a bulk method where several gold pellets are degassed in a mica tray held over the alcohol flame. This method tales less time but care should be taken to prevent the gold pieces from sticking to each other.

24. 3. Heating in an electric annealer In this the desired amount of gold is placed in the compartments of the annealer and the lid is closed. The gold is heated to 850F for ten minutes and then allowed to cool before it is placed in the cavity.

25. Hazards During degassing :- 1. Overheating – it should be avoided because it may cause the gold to become brittle or melt and render it unusable 2. Under heating – it should be avoided because it fails to render the gold surface pure.

26. 2.Compaction of Direct gold Two fundamental principles involved in compaction of cohesive gold are- i . Weld the gold into a cohesive mass

ii. Wedge as much gold as possible into the tooth preparation.

27. Direct gold that is in a cohesive state should only be used
⬇️
Direct gold is inserted into tooth preparation and suitable, biologically compatible compacting force must be delivered under force
⬇️ Welding occurs because pure gold with an absolutely clean surface coheres as a result of metallic bonding. The purpose of the force is to weld the gold into restorations containing minimal porosity or internal void spaces
⬇️
As the gold is forced and compressed into a tooth preparation, succeeding increments cohere to those previously placed

28. Methods of compaction Various methods available are:

1. Compaction with mallet and condensers i . Hand mallet
ii. Electro-mallet
iii. Pneumatic mallet 2. Compaction with hand condensers: pyramidal serration on face for additional lateral force along with direct compressive forces.

29. Condensers for compaction 1. Condensers are designed to deliver forces of compaction to direct gold.
2. Condensers used in the handpieces of the electromallet or pneumatic mallet consist of a nib, or working tip, and a short shank that fits into the malleting handpiece.
3. Condensers used with the hand mallet are longer and have a blunt ended handle that receives light blows from the hand mallet.
4. Condenser nibs are available in several shapes and sizes and have pyramidal serrations on the nib faces to prevent slipping on the gold.

30. 3. Condensers used with the hand mallet are longer and have a blunt ended handle that receives light blows from the hand mallet.
4. Condenser nibs are available in several shapes and sizes and have pyramidal serrations on the nib faces to prevent slipping on the gold.

31. Compaction technique for gold Foil 1. Stepping motion: Compaction begins when a piece of gold is placed in a tooth preparation. The gold is first pressed into place by hand, then a condenser of suitable size is used to begin malleting in the centre of mass. Each succeeding step of the condenser overlaps (by half) the previous one as the condenser is moved toward the periphery in an orderly stepping motion.

32. 2.Line of force The line of force is important when any gold is compacted. The line of force is the direction through which the force is delivered (i.e. the direction in which condenser is aimed). Correct hand - malleting technique require a light, bouncing application of the mallet to the condenser rather than delivery of heavy blows.

33. Compaction Technique of E-Z gold Compaction Technique :
Using a condenser, the first pellet of E-Z gold is pressed into the depth of the tooth preparation and tamped into position.
A small condenser is selected to thrust and wedge the gold into opposing line angles and against opposing walls, to secure the mass in the preparation.
Additional pellets are added (one at a time, banking against the prepared walls) until the entire preparation is filled.

34. GENERAL PRINCIPLES FOR DIRECT FILLING GOLD RESTORATION • 1. Build up of restoration . A) Tie formation- this involves connecting two opposing point angles or starting points filled with gold with a transverse bar of gold. This "tie" forms the foundation for any restoration in direct gold. B) Banking of the walls : This consists of covering each wall from its floor or axial wall to the cavosurface margin with the direct gold material. Banking should be done simultaneously on the surrounding walls of the preparation.

35. C) Shoulder preparation : This consists of connecting two opposing walls with the direct gold material to completely fill up the restoration.

36. 2) "Paving" of the restoration : To overfill the preparation every area of the cavosurface margin should be individually covered with excess cohesive gold foil. This is condensed with a rectangular "foot" condenser. 3). Surface hardening of the restoration The rectangular condenser is used with the highest possible condensation pressure in all directions on the surface of the restoration to strain harden the surface gold.

37. 4. Burnishing ; This is done with a suitable burnisher moving from the gold to the tooth surface. This enhances the surface hardening and also produces good marginal adaptation of the gold.• 5. Margination : This step uses sharp gold knives to remove excess gold from the surface to the tooth.

38. 6) Burnishing It is important to burnish the surface of the gold restoration after margination so as to eliminate marginal discrepancies and to strain harden the surface. 7) Contouring This step uses knives, files or finishing burs to create the proper occlusal anatomy. Burnishing is done again after contouring .

39. 8) Finishing and polishing Direct gold restorations require very little finishing if the previous steps are properly done. Finishing can be done using tin oxide powder on soft bristle brushes or rubber cups. 9) Final burnishing This is done after polishing to make the surface of the restoration smooth and free from voids.

40. Indication Class 1 Cavity : Direct gold is indicated for small carious lesions in pits and fissures of posterior teeth and lingual surfaces of anterior teeth. Class 2 cavity : Direct gold is indicated for minimal proximal caries in posterior teeth especially premolars when marginal ridges are not subjected Ito to heavy ‘occlusal stresses.

41. Class 3 Cavity : Can be used for small carious defects in anterior teeth when the defect is only on the proximal surface and esthetics will not be affected Class 5 cavity : For minimal caries in the Cervical one third of teeth direct gold can be used. Also for small abrasion, erosion or abfraction defects on the facial surfaces of teeth.

42. Class 5 cavity : For minimal caries in the Cervical one third of teeth direct gold can be used. Also for small abrasion, erosion or abfraction defects on the facial surfaces of teeth. Class 6 cavity: For restoration involving incisal edges or cusp tips direct gold can be used, provided there is no heavy occlusal stress. Defective Crown margin : It can be repaired with direct gold .

43. Contraindication Very large pulp chambers
Severely periodontally weakened teeth with questionable prognosis
Patients for whom economics is a severely limiting factor
In handicapped patients who are unable to sit for the long dental appointments required for this procedure Esthetics: When esthetic is the main concern it is not recommended.
Access and isolation difficulties

44. Conclusion Direct filling gold still remains one of the most conservative and long-lasting restorations in dentistry. Well placed direct gold restorations provide excellent service to patients for lifetime. However, the use of this material is on the decline in the present times because of its high cost, lack of technical expertise and the ever Increasing demand for esthetic restorations .

45. Reference Sturdivant's art& science Operative Dentistry – Second South Asia Edition Clinical operative dentistry – 2nd Edition Remya Raghu and Raghu Srinivasan
Textbook Of Endodontics: Nisha Garg Amit Garg 2 nd edition Basic dental materials –john j manappallil 4 th edition

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