H.F. ADAMS (AUTUMN 1978), AMALGAM—A TARNISHED IMAGE—DESERVES BETTER, OPERATIVE DENTISTRY, VOL3(4), PP. 142-143

POINT OF VIEW 

Amalgam-A Tarnished Image – Deserves Better 

Silver amalgam, used in approximately 80% of all dental restorations (Lambert, 1973), seems easy to manipulate and carve. However, it is undoubtedly the most abused of the dental restorative materials. It is usually placed without the benefit of the rubber dam, often contaminated with saliva or sulcular fluid, and a quarter of all restored proximal surfaces have gingival overhangs (Gilmore, 1971). More times than not the contact is improperly positioned, the surface is left unpolished, and the opposing cusps accommodated by overcarving and deepening the occlusal anatomy. These imperfections may result in plaque retention and periodontal inflammation, food impaction,

occlusal trauma, fracture of the restoration or, if the tooth is weak, the cracked tooth syndrome. 

Contributing Factors from Dental History 

Enter, in the late 1950s and early 1960s, a shortage of dentists all learning to use highspeed instrumentation, the scarcity of fluoridation, and the onslaught of the post-war teenager with rampant tooth decay. Compound this overwhelming problem with the popularity of micro-cut alloy, increased coverage of dental insurance, the management expert, and a saturated appointment book, and the stage is set. 

Do it faster was promoted and multiple matrix bands were in vogue. Very little was known about the dynamics of occlusion so, to avoid postoperative fracture of the amalgam, the occlusal anatomy was conveniently overcarved or deepened. The shrinking micro-cut alloys with their high content of the residual complex of tin and mercury deteriorated at a rapid yet predictable rate. 

To compound the problem most of the profession were reluctant to accept the merits of using rubber dam to isolate and control the field of operation. As Ireland (1962) has said, “Probably no technique, treatment or instrument used in dentistry is so universally accepted and advocated by the recognized authorities, and so universally ignored by the practicing dentist” as the use of rubber dam.

The insurance companies are rapidly expanding and may control the market place. Their fee schedules based on a fixed fee per surface restored rather than a more realistic fee based on the time needed for the professional service obviously influence the quality of amalgam restorations.

Proposed Solution

All is not lost. 

Increases in the dentist:population ratio, fluoridation, plaque control, and the use of well trained auxiliary help have in most cases reduced the appointment schedule to a manageable level.

The operative dentist must change his attitude toward silver amalgam. It is not just a temporary material until the patient can afford gold. A good amalgam placed where indicated has a longevity of 20 years or more (Christensen & Lundeen, 1969). Research has produced an alloy with greater strength, more resistance to corrosion, controlled expansion, and less creep. The ultimate restoration should be durable provided the principles of preparation, placement, and finish are followed. Obviously the use of rubber dam is advocated.

Above and beyond technique is the need for an appropriate fee for the professional service. Traditionally, charges for amalgam have been made on the basis of a fee per surface restored. This method of establishing a fee is inconsistent with the value of the service to the patient. For example, amalgam is a superior material to composite for restoring the occlusal surfaces of the posterior teeth but this superiority is not reflected in the fee charged for each type of service (see table). The fee for a class 1 composite is about 25% more than that for a comparable class 1 amalgam. Since the times of preparation and insertion are about the same, the larger fee for the composite must be justified by the esthetic appearance of the restoration and by less inconvenience to the patient in not having to return for a polishing appointment. 

Selected fees from report of Bureau of Economic Research and Statistics (1978) Journal of the American Dental Association, 97, 680.

Another example of the disparity in fees is the hourly difference in gross income from amalgam restorations when compared with porcelain-fused-to-metal crowns. An experienced operator can prepare, place, and subsequently polish two 3-surface amalgams per hour. The same operator can comfortably prepare a tooth and insert a crown in about an hour and fifteen minutes. Both procedures require two appointments. When a laboratory charge of $54.00 per unit is subtracted from the fee for the crown there remains an income of $105.42 per hour. Three-surface amalgams, on the other hand, yield $51.66 per hour. Will they both last 20 years? Is the esthetic crown worth twice as much as the amalgam restoration? Can we double our productivity to 12 surfaces of amalgam per hour and still preserve quality? Or should the fee for a 3-surface amalgam of good quality be increased to the point where it provides adequate monetary incentive to do it right?

University of Washington, School of Dentistry, Department of Restorative Dentistry SM56, Seattle, WA 98195, USA

HARMON F ADAMS, DDS, assistant professor. Dr Adams conducts a private practice part time and is the mentor of two study clubs. He is a member of the American Academy of Gold Foil Operators, the Academy of Operative Dentistry, and the Seattle Indirect Inlay Study Club. 

References

CHRISTENSEN, G J & LUNDEEN, H C (1969) Restorative dentistry in general practice. In The Dental Specialties in General Practice. Morris, A L & Bohannan, HM, editors. Ch 11, pp 513-568. Philadelphia: W B Saunders.

GILMORE, H W (1971) Overhanging restorations and periodontal disease. Journal of Periodontology, 42, 8-12.

IRELAND, L (1962) The rubber dam. Its advantages and application. Texas Dental Journal, 50 (3), 6-15.

LAMBERT, R L (1973) Amalgam restorations. In Advanced Restorative Dentistry. Baum, L, ed . Ch 6, pp 73-98. Philadelphia : W B Saunders.