One of the biggest breakthroughs in dentistry is composite popularly known as tooth colored filling material. We all remember our early childhood dental visits when amalgam or rather silver fillings were placed when we developed cavities. It is an extremely strong material of choice but not very esthetic. Some of these fillings last for even twenty plus years not causing any problems whatsoever.
The major advantage of amalgam is its strength and durability. It worked really well on large cavities especially on back teeth and also not very technique sensitive. The cavity had to be drilled and then amalgam was mixed and packed into the cavity. It was then carved and burnished to get the natural tooth anatomy, a relatively simple procedure that works to this day. As with any material amalgam has its own set of disadvantages. Silver amalgam has mercury and over a course of time can leach out mercury and discolor the tooth. As it is grey in color it cannot be used in front teeth. Since the material works by mechanical retention, the cavities needed to be made pretty large for the material to be retentive and stay on the tooth.
Composite or tooth colored filling material on the other hand is extremely esthetic. They come in different shades and can be matched to any natural tooth. When done right they blend so well that it is hard to differentiate the filling material from the natural tooth. They work by bonding or latching on to the tooth surface and hence this is a great material of choice when the cavities are small as the drilling can be kept minimal and solid tooth structure can be conserved. But it is a highly technique sensitive procedure. Isolation is the key and the tooth must be kept extremely dry. The tooth is first etched with 37% phosphoric acid. Then a bonding agent is applied and cured using uv light for about 10 seconds. Then the composite or resin material is added in increments of 2mm and then cured for about 20 seconds. This procedure is repeated till the tooth is completely filled. This material works great on small cavities and chips or fractures on your front teeth.
One common question that many patients ask is “ Do I need to change my silver fillings to composite? “ The answer to this question is again it depends. If the filling is a large amalgam then changing it to composite is not a great choice. Since composite works on being light cured it can cause postoperative sensitivity due to shrinkage. So when the cavity is large, composite shrinks over time and the patient can develop recurrent decay. In this case crowning a tooth that has a large discolored amalgam filling is a better option. But smaller silver fillings can be replaced with composite and they can function well. Composite is not the most durable and can chip or crack under heavy bite forces which can be withheld better by amalgam fillings or crowns. So its not a great choice when the cavity is large or when the patient has a very strong bite.
As with any material having its set of advantages and disadvantages, composite is still very widely used in dentistry and is a great esthetic and cost effective option for patients to restore form, function and esthetics.