Modern dental fillings
What are the advantages and disadvantages of white dental fillings over the amalgam used in the past? Can they be used in all cases? Will they last as long?
Technological progress is changing many fields of human activity beyond recognition, and dentistry is no exception. New materials, devices and procedures offer patients ever-improving treatment options. In the past, white fillings began as an imperfect colour-changing material, with limited durability and low mechanical resistance. How are today's modern fillers doing?
Today's white fillings are made of photocomposite resin, a material that solidifies "on command" when exposed to blue light. They are colour-stable, can imitate the appearance of your own tooth very well and can be used without any worries, even in the heavily loaded places at the back sections of the teeth. In the vast majority of situations today, they represent the ideal material and are what we turn to first.
While from the patient's point of view the main advantage is unsurpassed aesthetics, from the doctor's point of view it is the strengthening of the tooth. The old amalgam fillings only used to "fill the hole". When biting, teeth remained as firm as if they had no filling, and often cracked. Modern white fillings are very strongly attached to the tooth and thus can hold its weakened parts together and significantly extend its life.
They also allow for a more gentle drilling process. In the case of an amalgam, it was always necessary to ensure that the lower part of the filling was wider than the upper. This was so that the amalgam remained wedged in the tooth after solidification, as this was the only mechanism by which it was held in the tooth. In order to ensure this shape of the filling, it was usually important to drill more than the extent of the decay. In the case of white fillings that are attached to the walls of the tooth, on the other hand, we only need to remove the damaged tissue yet they will still hold reliably.
What are the disadvantages of white fillings? The main one is sensitivity to moisture. When creating a white filling, it is necessary to ensure a dry working space, as any moisture would cause the filling to leak, resulting in a risk of caries. In general, the whole work procedure requires a lot of knowledge, patience and diligence on the part of the attending physician, and a lot of time needs to be devoted to the treatment.
In addition to the sensitivity to moisture mentioned above, the doctor must also deal with the shrinkage of the material that accompanies solidification. For that reason, the filling must be built up with many thin layers, which are placed side by side with respect to complex biomechanical rules. If this is not followed, there is a risk that strong tension will arise in the filling, which may manifest itself as pain in the treated tooth and possibly even as a rupture (the filling pulls the opposite walls of the tooth together). In such a case, if the bonding layer is not formed correctly, the filling is torn off from the tooth wall and caries occurs in the joint over time.
Another disadvantage is the fact that the photocomposite resin does not have any impact on bacteria in any way. Amalgam suppresses the metabolism of bacteria in its immediate vicinity and thus slows down the formation and progress of tooth decay. In the case of amalgam fillings formed in a hurry in just a few minutes, where a part of the caries remained underneath or which were not sealed, the remaining caries does not proceed as fast as under the white filling. As such, a poorly made white filling is far more dangerous to the patient than a poorly made amalgam, because the decay progresses very quickly under or next to it. Because the filling is attached to the tooth, this caries does not show that the filling might fall out, which can further delay its detection. Moreover, a white filling may not be suitable for patients who are unable or unwilling to clean their teeth sufficiently, in which case amalgam is a safer choice.
While the patient always benefits from the advantages of white fillings, their disadvantages do not diminish this benefit to the patient in any way, as they only place significantly greater demands on the dentist. So if your doctor is careful enough, spends time with each filling and undergoes regular training, you don't have to worry about white fillings and in most situations they are the best alternative for you.