Obsolete Dental Dental materials http://www.ncbi.nlm.nih.gov/pubmed/23829005Materials

 

Dental materials have come a long way. If you can look back to the 1950s, so much of what is taken for granted now didn’t even exist then!

Dependable tooth colored composite materials, which now comprise the bulk of dental fillings, had not been developed. On posterior teeth, the fillings were made of amalgam (silver colored fillings) which are still in use today. They were sometimes used on front teeth, which is definitely not esthetic. An esthetic improvement was to use a white silicate cement, which was at least white, but it needed to be replaced every 2 years or so because it would wash out. This has been replaced by the modern composites and bonding materials which come in a host of shades and last much longer.

Another archaic material is the gold foil. This is thin flakes of pure gold which is pretty soft. The gold is placed inside the cavity preparation and is mechanically hammered into the space, adding more and more until the cavity is filled up. The “hammering” can be done by hand or with an electric device. The positive sides to this is that it really fills in the space well and for smaller fillings, lasts a very long time. The down sides include the esthetics of it, the difficulty and length of time to do the procedure, the cost, and the effect on the nerve of the tooth with the hammering of the filling into place. This procedure was included in my curriculum in the late 1970s but I haven’t seen it in a while. This procedure was popular in California and had been part of their licensing examination. Now it’s pretty much in oblivion.

Still done are gold inlays and onlays. These are fillings that are made in a laboratory, smaller than a crown, but are cast in gold and later cemented. The advantage to these are that they are gold and are thought to last longer than regular fillings. An onlay is more conservative than a crown since parts of the natural tooth can be saved. The disadvantages are cost, time and esthetics. These have been replaced by porcelain inlays and onlays which are more esthetic and can sometimes be performed chairside.

Materials for making crowns have become so much better! For crowns on front teeth, gold was used. The front part of the gold crown was cut back so that a porcelain denture tooth (at least tooth colored) could be cemented. This sometimes showed some of the gold around the tooth and it could also fall out. The big improvement came in the 1960s when someone figured out that porcelain could be fused to metal (usually a gold alloy) and the porcelain, after baking at a high temperature, would stay and look much more esthetic. Although this technique is still commonly used today, we have other choices, including all porcelain crowns which are very strong, and zirconium, a white metal, which can be used by itself or have porcelain fused to it much like the old gold alloys.

Most of the other dental materials have been tweeked over the years. This includes dental cements, anesthetics, partial denture materials just to name a few. I am so happy to be able to deliver better and better quality dental work, with better looking and more comfortable materials.