Why Gold Foils?

 

NORWOOD  E. LYONS, D.D.S.

 

Lecturer, Operative Dentistry, University of California School of Dentistry, San Francisco, California.

Presented at the Annual Meeting of the American Academy of Gold Foil Operators in Bethesda, Maryland on October 28, 1967.

Reprinted from the Journal, American Academy of Gold Foil Operators, Vol. XI, No. 1, April 1968

 

IN THIS MODERN AGE of dentistry, with the high speed and other up-to-date equipment, we have a tendency to forget the fine art of cavity preparation. Gold foil, more than any other type of proce­dure, offers an answer to this problem. It is an exacting preparation and tests the skill of the operator. When well done, no other restora­tion can compare to it.

Over the years, many new filling materials have been developed, especially the plastics under a variety of trade names, but, to date, none have been satisfactory as a restorative material.

Owing to the fact that the plastics and cement silicates are subject to change of form during the hardening process, and that they are lacking in crushing resistance and edge strength as com­pared with most of the non-plastics, they are not nearly so permanent in character. From a standpoint of lasting qualities, gold is the king of restorative materials. In some sections of the United States, gold foil as a restorative material is not used extensively, yet many prac­titioners and teachers are recognizing that, in spite of the more recently introduced materials and techniques, gold foil still holds the leading position in choice of materials. A true recognition of its value and limitations and a development of skill in its use can make it take its place with other restorative procedures.

Since the introduction of the modern cast gold inlay, the sili­cates and acrylic resins, the use of cohesive gold has diminished. This is to be deplored since there is no material to compare with it as a preserver of tooth structure. However, gold, as a restorative material, still occupies an important place in dentistry and will probab­ly continue to do so for a long time.

The principal disadvantages of the cohesive gold foil restoration is the time required for its introduction in large cavities, and the possible physical and nervous strain on both patient and operator resulting from its manipulation. These disadvantages may be re­duced to a comfortable minimum with the increased skill of the operator. In fact, many times, with an experienced operator, gold foil operations can he less strenuous on patient and operator than the construction of a gold inlay. This is particularly so in the case of the Class V or Class III preparation where gold is indicated.

The many failures resulting from an indiscriminate use of the gold inlay, the silicates and acrylic resins by the profession dur­ing the last several years have gradually led to a revival of interest in the cohesive gold foil restoration, and it is slowly returning to the place which it deserves.

If the full story of dentistry 's service to humanity is ever told, gold foil must be given the major credit for this service. If the source is sought for the outstanding achievement in saving the natural teeth after they are attacked by decay, gold foil must claim its full share in this beneficial function.

For an appraisal of the gold foil restoration,2 the work of Dr. Gerald Stibbs of the University of Washington, School of Den­tistry, has been included in this essay for its honest and sincere ap­proach to the problem. As Dr. Stibbs points out, "As one appraises gold foil restorations in operative dentistry, it is well at the outset to establish a justification for the discourse.

When one reviews the literature of operative dentistry for the past fifty years, it is apparent that the great leaders in the field have thoroughly and painstakingly and brilliantly taught by word, picture and clinic all the fundamental principles as well as the mechani­cal refinements to produce the ultimate in restorative dentistry. Be­yond the purely technical presentations, there are also any number of pleas for an increased use of foil, and for a keener perception of the obligation of the profession to perform restorative procedures more conscientiously and more universally. There are three reasons for this.

First — The continued and increased use of foil in dental practice is so tremendously important to the future security of den­tistry as a truly scientific profession.

Second — Repetition in one form or another is essential to maintain on the scales of dental practice the current degree of bal­ance for the adequate use of gold foil.

Third — There has been an unfortunate reticence in emphasizing the economic soundness of fine operative procedures for a just remuneration. From a purely operative point of view, foil takes second place to nothing else in the incipient stages of decay or erosion.

It is of particular value in the small pit and fissure cavities, in the gingival third cavities of the incisor, cuspid and bicuspid teeth, in the mesial and especially the distal surfaces of the incisors and cuspids when incisal angles are not involved; in the proximal sur­faces of some posteriors, especially the upper and lower first bicuspids; and finally in the class six cavity or the cupped out depression in the dentin where the enamel of a cusp tip has been worn through." While generally familiar to members of this Academy, it may not be remiss to be reminded of the properties of gold which make it so valuable to us.

Gold is one of the first metals used by man and owing to its varied and remarkable properties as well as its intrinsic value, it is recognized as the most noble of metals. From the earliest historic records down through the ages, it has played a prominent part in the development of our present knowledge of metallurgy. Several collodial forms of gold have been introduced for its therapeutic value in malignant diseases.

Gold possesses a number of important characteristics which render it of special value as a restorative material.

 

These characteristics may be summarized as follows:

First — Cohesiveness to a greater extent than any other metal. This quality depends largely on purity. The best golds for restorative purposes are about 999 parts in 1000 pure gold.

Second — Softness during manipulation. This quality depends largely on purity.

Third — Malleability. It exceeds all other metals in this respect. It may be reduced by beating to 1/250,000 of an inch in thickness.

Fourth — Ductility. It is the most ductile of all metals. One grain of pure gold may be drawn into a wire nearly five hundred feet long.

Fifth — Hardness in bulk form. Gold is about one-third as hard as the diamond. This property is largely increased by alloying and by hammering or rolling. lts Brinell Hardness is given as 48.0 in comparison with copper 74.0 and silver 59.0.

 

C O H E S I V E  G O L D  F O I L

The prepared pellets that come in various sizes are the most com-


monly used. However, many gold foil operators prefer to roll their own from the 4 x 4 inch sheets. The No. 4 sheet can be hand-rolled but cannot he prepared successfully by the manufacturer. The main advantage is that each pellet has more bulk and less mass. The advantages and disadvantages of cohesive gold as a restorative ma­terial are:

 

ADVANTAGES

Insolubility in the oral fluids.

Perfect adaptability to cavity walls if properly worked.

Perfect weldability to a cold state.

Great density, crushing resistance and edge strength.

Low tendency to molecular change, since it is free from objectionable shrinkage or expansion.

Capability of receiving and maintaining a high polish.

No inter-cementing substance necessary.

Excellent tissue tolerance.

 

DISADVANTAGES

The color may be objectionable in certain areas of the mouth.

Difficulty of manipulation by inexperienced operators.

Force of compaction in very deep lesions may have ad-verse traumatic effect.

Periodontally involved teeth with a great amount of bone loss are poor risks for foil restorations.

 

Gold is insoluble in and is not oxidized by the oral fluids or their contents. Consequently, restorations made with it do not dis­color or disintegrate. If properly condensed and wedged into place, gold foil is capable of extremely close adaptation to cavity walls.

Dr. G. V. Black,3 the father of operative dentistry, proved this in his experiments many years ago. The hardness of gold restora­tions depends on the efficiency and amount of malleting used during its introduction to the cavity. The elasticity of dentin assists in pro­ducing a near perfect type of adaptation. The grip of the elastic dentin will depend upon the force with which the gold is wedged between opposing cavity walls.

Factors influencing selection of gold foil as a restorative ma­terial are as follows:

Strength of cavity walls.

Character of occlusion (strength of the bite and character of excursions of the mandible).

Presence or absence of abrasion.

Accessibility of the cavity.

Skill of the operator.

Esthetic consideration.

 

The care which the patient gives the mouth and the suscepti­bility to caries will always have a bearing. Gold is the most per­manent of the restorative materials and its need will be proportional to the demand for lasting qualities in these cases. The profession is indebted to such men as Doctors Woodbury, True, Ferrier, Hollen­back, Rule and others for their untiring efforts and dedication to the profession so that we may do better dentistry.

This Academy should do all in its power to remind others in the profession of the tremendous merits of gold foil as a restora­tive medium. When used properly, and where indicated, it is still one of the most permanent and excellent means at our disposal for saving teeth in health and function. Current techniques of manipu­lation make its use no longer a problem in respect to stress or strain on either patient or operator. There is no restoration more beautiful and serviceable than a well inserted gold foil. The satisfaction it renders to both operator and patient is indeed gratifying.

 

 

REFERENCES

McGeehee, True, Inskipp: A Textbook of Operative Dentistry. McGraw-Hill Book Co., The Blakiston Division, 1956, pp. 355-382.

W. J. Simon: Clinical Operative Dentistry. W. B. Saunders Co., Philadel­phia, Pa., 1956, pp. 278-279.

G. V. Black: Operative Dentistry, Vol. II, Physical Properties of Filling Materials and Correlation of Forces Concerned, pp. 224-237. Medico-Dental Publishing Co., Chicago, Illinois, 1914.

 

Scanned & Edited By Dr. John R. Sechena