Many people ask us why Willowdaile Cosmetic and Family does all of our fillings on back teeth using composite (white) fillings rather than silver amalgam.
Silver amalgam is composed of silver, copper, tin, zinc and mercury. The mercury is what allows the formulation to be in a putty-like consistency while it is placed in the tooth and then harden to a metal consistency. Amalgam has been the filling of choice for about a century. Its advantages include strength, durability, low cost and ease of placement.
An amalgam can be contaminated by saliva or blood during placement, and its longevity will not be affected. Amalgam’s disadvantages include undesirable aesthetics (they start out silver and end up black as they age), lack of bonding, frequency of tooth fracture and some concern about mercury toxicity (although this has never been proven scientifically).
Composite fillings are very different from amalgams in many respects. They are made from a plastic resin with varying amounts of glass fillers, depending on the brand. Composites have been in use since the 1960s but were initially used only for front teeth.
What sets composites apart from amalgam is that:
- They are tooth-colored.
- They are bonded to the tooth. This is the most important feature of composite fillings, and the one that has caused such a revolution in dentistry.
The composite is microscopically attached (bonded) to the tooth through a three-step process. First, the tooth is treated for 15 seconds with a mild acid which conditions, or “etches,” the tooth. It provides microscopic irregularities in the enamel and opens small tubules in the dentin of the tooth.
The second step is the placement of a bonding agent. This is a very thin type of composite that flows into the enamel irregularities and dentinal tubules. It is then cured (hardened) by our dentists or our hygienists with a very bright blue curing light. This very thin initial layer is now microscopically locked into the surface of the tooth.
The third step is the addition of a chemically similar composite filling material that then chemically bonds to the first layer. This produces a filling that is actually bonded to the tooth, instead of being simply placed in the tooth like you would pour cement into a post hole.
When properly done, composites will last as long as amalgam, look just like a natural tooth and strengthen, rather than weaken, the tooth.
For more information on tooth-colored restorations, please call Willowdaile Cosmetic and Family at 919-479-5800 to meet with Dr. Vincas Sidrys or Dr. Matthew Garcia for a composite dental filling in Durham, North Carolina.
The resin material in dental fillings are made of a plastic that is one of the latest improvements in dental technology. Each filling should last for several years. However, patients should take care of the following: