TL;DR
A composite filling is a tooth-colored mix of resin and fine glass particles that’s bonded into a tooth and hardened with a curing light. It repairs small and moderate cavities, chipped edges and worn areas near the gum, on front and back teeth, in one appointment. It contains no metal and no mercury. At Stone Falls Dental Care we look for decay early with low-radiation digital X-rays and an intraoral camera, because a small cavity needs only a small filling. Larger damage may call for an inlay, onlay or crown.
What is a composite filling?
A composite filling is a tooth-colored material made of plastic resin and very fine particles of glass or quartz. It goes into the tooth as a soft paste, gets shaped by hand, and hardens in seconds under a blue curing light. Because it comes in many shades, it can be matched closely to the enamel around it, and on a front tooth it can even be layered to copy the slightly clear tip of the edge.
Unlike older silver amalgam, composite bonds to the tooth. A thin adhesive layer locks it to the enamel and the dentin beneath, so the cavity can be prepared smaller, with less healthy tooth cut away to hold the filling in.
When is a composite filling the right repair?
Composite is the right repair for most small and moderate cavities and for minor damage you’d like to fix without it showing. We commonly use it for:
There are limits. A very large cavity, or one that has left the cusps thin, puts more stress on a filling than it’s built to carry for long. In those teeth, a porcelain inlay or onlay made by a laboratory usually lasts better, and we’ll explain why before suggesting it.
- New cavities on the chewing surfaces or between the teeth
- Chipped or worn front edges
- Notches and worn areas near the gumline
- Replacing a small old filling that has failed or decayed at its edge
How is a cavity filled with composite?
A composite filling takes one appointment, and most of the time goes into careful layering. We numb the tooth, remove the decay, and clean and shape the space. The surface is prepared with a mild etching gel and coated with a bonding agent so the composite has something to grip.
The composite then goes in a layer at a time, each one hardened with the curing light before the next. Layering keeps the material from pulling away from the walls as it sets. Last, we shape the chewing surface, check your bite with marking paper, and polish the filling so it feels like enamel to your tongue.
How do we find cavities while they’re still small?
We find most cavities at routine checkups, before they hurt. Early decay between the back teeth is usually invisible in the mirror, so low-radiation digital X-rays are how we see it. An intraoral camera lets us show you a suspicious spot on the screen, close up, so you see what we see before deciding on treatment.
Timing matters because decay grows. A cavity caught in the enamel needs a small filling. Left until it aches, the same cavity can reach the nerve and need root canal treatment and a crown. Some very early spots in enamel can even be watched and strengthened with fluoride rather than drilled.
How long do composite fillings last?
A composite filling commonly lasts many years, with the size of the filling, your bite and your daily care making most of the difference. Small fillings in teeth that don’t take heavy grinding tend to last longest. The edges can pick up stain from coffee, tea or red wine over time, and a stained edge can sometimes be polished rather than replaced.
You don’t need to swap sound silver fillings for composite just because of their color. The American Dental Association does not recommend removing intact amalgam fillings. When an old filling does break down, we replace it with composite as part of normal care. Your insurance usually covers fillings, and our financial options page explains the rest.