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Direct Composite Resin Fillings as 

Alternative to Amalgams – A Case Report

Ed de la Vega, DDS

Canoga Park, California

Introduction:

For over a century and a half, the “standard” restorative filling material for posterior teeth is silver amalgam. Aside from a lack of a “better alternative”, these fillings are very popular due to their low cost and ease of manipulation. They are even known to be “forgiving”. However, they have many shortcomings. They breakdown and degrade over a period of time due to corrosion and they make teeth susceptible to fractures from the required removal of large bulks of healthy tooth structure to attain proper retention and strength. Furthermore, they are esthetically poor at best.

When Bounocore in the 1950’s introduced a procedure to bond fillings to the enamel, the  popularity of amalgams begun its gradual decline. The new procedure started and fueled the so-called “esthetic revolution” and gave birth to the different types of bonded resin filling materials. The development of these materials came in leaps and bounce. Present materials are so versatile that they can be used not only for anterior teeth but for posteriors as well.

As good as they are however, these bonded resin filling materials still have some shortcomings. They are very “technique sensitive”. As moisture control is a must to have a successful and long lasting restoration with these materials, the use of a rubber dam is imperative. Working with these materials is time consuming and they can be very expensive compared to amalgams. Due to their rapid acceptance as “esthetic restorative materials”, manufacturers are introducing many different kinds in such a very rapid pace that some materials are marketed without benefit of long term clinical trials. In certain cases, materials are introduced in the market and then pulled-out before a study about their efficacy is even started. Consequently, clinicians have yet to develop unqualified confidence in these materials. Short-term studies, however, increasingly show that they have a lot of potential. Amalgams may soon be “things in the past” particularly given the unfounded allegations as the “cause of certain debilitating diseases”; and the increasing demand from patients for esthetic restorations.

A Case Report:

A twenty-eight year old professional magician presented to our offices requesting “removal of her silver fillings” and restoring them with “white” fillings. She was very worried and concerned that her many silver fillings will “show-up” while doing “close-up magic” at her maiden television show.

Examinations revealed amalgam fillings in most of her posterior teeth. (Fig.1) Most have leaking margins and some recurrent decay. X-rays showed no underlying pathology on these teeth other than obvious signs of recurrent decay. She has a healthy periodontal status and no TMJ and occlusal discrepancies to speak of. Case presentation and treatment planning were made as well as financial arrangements. The patient requested that we start with her upper left posterior teeth as this is where she feels the most sensitivity to temperature and sweets. Both molars and bicuspid on the said quadrant have amalgam fillings but only the bicuspids are restorable with direct composite fillings. The molars will be best served with lab-fabricated indirect composite restorations due to the size of their existing restoration.

We decided to do the bicuspids first, to give the patient an idea how they will look and function after we are done and to create a proper distal contour for the future indirect composite restoration for the molar.

The teeth were properly anesthetized and a rubber dam was placed. Using a carbide bur, the existing amalgam was removed with copious air/water spray and a high volume evacuator. Care was taken so as not to extend the margins of the cavity beyond its old borders to conserve healthy tooth structure. Caries detection stain was used to check for recurrent decay. Cavity cleanser was applied and the preparation was washed and lightly dried. An appropriate matrix on a band holder was placed, properly contoured and wedged.  Phosphoric acid 38% etching gel was applied for 15 seconds, rinsed and blot dried. Desensitizing solution was applied to the preparation for 20 seconds and the excess blot dried with a cotton-tipped microbrush. With the dentin still slightly moist, Bond I, adhesive was applied with a brushing motion for 20 seconds. Excess was blot dried and another dose of Bond I was re-applied leaving the preparation with a shinny glistening surface. (Fig 2) This was then light-cured for 20 seconds. A thin layer of flowable composite was applied lightly to all the walls and light-cured for 20 seconds. Correct shade packable composite resin applied and light cured in increments to about one-half millimeter of the cavo-surface margin. Prior to light curing the last increment, the anatomy was shaped with composite instruments and the occlusal grooves where accentuated with a brown colored stain. (Kerr Color) applied using a tip of a sharp explorer. The final layer using a translucent material (Kerr, Shade T1) was placed to overlay and protect the stain, build up the final increment of composite, and blend with the surrounding enamel. This was then light-cured for 40 seconds. The clamp, wedge, matrix band and rubber dam were removed and the tooth was given its final shape and contour using a bullet shaped finishing burs. Occlusion was likewise properly adjusted and the restoration was polished with various cups, points and brushes and diamond polishing paste (Kerr). Finally, it was etched, washed and lightly air dried before a layer of unfilled resin was applied and cured for 20 seconds. The unfilled resin layer serves as the final sealant for the restoration.

Final check revealed a very natural looking restoration with good contour, contact, anatomy and superior marginal integrity. (Fig 3 and 4).

Click on the Image to enlarge

Conclusion:

Direct bonded composite resin restorations can be excellent alternatives to amalgam fillings. However, to ensure predictable, functional, long lasting and esthetically pleasing restorations, strict adherence to proper clinical protocol such as the use of rubber dam for moisture control is imperative. It is also necessary to follow manufacturer’s suggested “directions” in order to produce consistent results.

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