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Composite bonding adds tooth-colored resin to a front tooth to repair a chip, close a gap, reshape a small or worn tooth, or fill a dark triangle at the gum line. In most cases nothing is removed from the tooth. It is done in the chair, usually in one visit, and it suits single teeth and limited changes. When several front teeth need changing, or a tooth needs to be made longer, porcelain veneers usually serve better. Bonding also needs upkeep: a repolish every year or two, and eventually replacement.
A chairside veneer or a small addition
Bonding comes in two sizes. A chairside veneer covers the whole visible face of the tooth in composite, built up in layers and shaped to a new outline; it is the composite equivalent of a porcelain veneer, made in the chair instead of a laboratory. A small addition changes only part of the tooth: a corner that chipped, an edge that wore unevenly, one side of a gap. Which one a tooth needs depends on how much of its shape has to change.
Where bonding works well
Bonding is at its best when a tooth needs more volume, not less:
- Undersized teeth, especially peg-shaped lateral incisors, the small teeth either side of the two front teeth. Adding composite brings them into proportion.
- Spacing, where a modest gap can be closed by adding a little to each neighboring tooth.
- Worn or chipped edges and small areas of missing enamel, where composite restores the outline.
- Black triangles, the small dark spaces that open between teeth near the gum.
The requirement in every case is room. Composite sits on top of the tooth, so the tooth must be able to take the extra thickness without looking bulky. Teeth that need added volume are ideal. Teeth that are already full-sized, or dark teeth that would need a thick layer to mask the color, are not.
Closing black triangles
Black triangles appear when the gum between two teeth no longer fills the space: after recession, after gum disease has cost some bone, or after orthodontic treatment has straightened teeth that used to overlap. They are hard to close well with ordinary bonding, because composite added at the gum line tends to leave a ledge that traps plaque and inflames the gum.
For these we use the Bioclear matrix technique. A clear, anatomically shaped matrix wraps the tooth below the gum line and lets us inject and shape the composite in one smooth, continuous contour from the root surface out to the contact point. There is no step for floss to catch on and nothing for plaque to collect in, and the result follows the natural contour of the tooth. Gum health has to be settled first, and not every triangle can be closed completely, but for the right case it is a good treatment.
Alignment and whitening first
Bonding is not a substitute for orthodontics. If the underlying problem is the position of the teeth, moving them with Invisalign solves it; covering it with composite adds a layer that must be maintained for the rest of your life and still leaves the teeth where they were. The same goes for color: whiten first, let the shade settle, then bond to match. Once the teeth are straight and the color is right, if the shape still bothers you, that is the moment for bonding or porcelain.
When we favor porcelain instead
We prefer bonding for single teeth and limited changes. When several front teeth need changing, our experience is that patients are happier in the long run with porcelain veneers:
- Porcelain is more lifelike, because a ceramist can build in translucency and detail that composite cannot match.
- It does not stain.
- It lasts longer.
Length is the other dividing line. If a tooth needs to be longer, we recommend porcelain. Likewise, a dark tooth that needs a thick layer of composite to hide its color ends up bulky, and porcelain handles that better.
Planning and placement
- Step 1 of 4 Consultation
We look at the tooth, the neighbors, the bite and the color, and agree on what you want to change. Where whitening or alignment should come first, we recommend that.
- Step 2 of 4 Design, where needed
A single tooth or a small addition is usually shaped freehand in the chair. For larger changes we can have the laboratory produce a digital wax-up and make guides from it, so the composite is built to a plan.
- Step 3 of 4 The bonding visit
The surface is cleaned and conditioned, the composite is layered and sculpted to shape, then hardened with a light. Most of the shaping and initial polish happen in this visit.
- Step 4 of 4 The finishing visit
A short second appointment to refine the shape and polish once you have lived with it for a little while. The final polish is what gives composite its shine.
Color matching is usually very good, because we match the neighboring teeth directly. Highly translucent teeth and teeth with distinctive internal characteristics are harder, and we tell you in advance if yours are.
What the visit is like
Most bonding needs no drilling and often no anesthetic. The tooth is cleaned and isolated, the surface is etched and a bonding agent applied, and the composite goes on in thin layers, each one shaped and hardened with a blue light before the next. The outline is refined with fine discs and strips, the bite is checked so the new edge meets the opposing teeth comfortably, and the surface is polished.
Allow an hour or two for a single tooth. You can eat normally the same day; the composite is fully hard when you leave. Avoid biting hard objects with the bonded tooth, and if you clench or grind at night, tell us, because a night guard protects composite as much as it protects enamel.
Upkeep and repairs
Composite loses its gloss over time. Modern materials hold up better than they used to, but brushing with abrasive toothpaste gradually dulls the surface, and stain can gather at the margins.
- Plan on having the bonding repolished with the fine polishing discs and pastes made for composite, every year or two in our experience.
- When you have a cleaning, tell the hygienist you have bonding; ordinary polishing paste scratches it, and a fine composite polish should be used instead.
- At some point bonding stops looking as good as it did and is redone.
Small defects can sometimes be repaired, but when a piece breaks it has usually broken at the weakest point, and patching the same spot tends to fail again. In that situation we prefer to replace the bonding, or, if it keeps failing, to ask whether the design or the bite is the real problem and whether porcelain would serve better.
Frequently asked questions
Does bonding hurt?
Usually not. Most bonding is additive, so there is little or no drilling, and many cases are done without anesthesia. If a chipped edge needs smoothing or a small amount of enamel is reshaped, we numb the tooth.
How long does bonding last?
In our experience somewhere around ten years is typical, with wide variation; porcelain veneers, by comparison, commonly serve twenty years or more. Bonding gradually loses its shine and may pick up stain at the edges, and at some point it is redone. Repolishing every year or two extends its life.
Will it match my other teeth?
For most teeth, very well, because we match the neighbors directly in the chair and adjust until it blends. Very translucent teeth and teeth with distinctive internal markings are harder to match, and we will tell you if yours are.
Can bonding straighten crooked teeth?
Not really, and we do not recommend trying. Adding composite to disguise crowding or rotation adds bulk and creates something that has to be maintained for life. Invisalign moves the teeth; bonding can then refine the shape if needed.
Can I whiten bonded teeth?
Whitening changes natural teeth but not composite. If you want whiter teeth, we whiten first, let the shade settle, and then bond to match. Existing bonding that no longer matches after whitening is replaced.
Bonding or veneers?
Bonding for one tooth or a small change, done in a visit or two, with no preparation and the understanding that it needs upkeep. Porcelain veneers when several teeth are involved, when length must be added, when the teeth are dark, or when you want the most lifelike and durable result. We will give you our recommendation for your teeth.
