Dental Sealants: A Simple Shield Against Cavities

Sealants are one of the least glamorous and most effective things in dentistry. A thin resin coating is flowed into the grooves of a back tooth and hardened, and the tooth becomes markedly harder to decay.

There is no drilling, no anesthetic, and the appointment takes a few minutes per tooth. The evidence behind them is unusually strong for a preventive measure.

Why back teeth decay where they do

Look at the biting surface of a molar and you see a landscape of ridges and valleys. Those grooves, called pits and fissures, are where the developing lobes of the tooth met during formation, and in many people they are deeper and narrower than a single toothbrush bristle.

Food debris and bacteria settle into them and cannot be brushed out. Acid produced in that sheltered space works on the enamel from a position no home care can reach, which is why the overwhelming majority of cavities in children and teenagers occur on these surfaces rather than on the smooth sides of teeth.

A sealant fills the groove, converting a deep narrow canyon into a smooth surface that a toothbrush can actually clean.

How they are placed

The tooth is cleaned and dried and isolated to keep it dry, which is the single most important factor in whether a sealant bonds well. A mild etching gel is applied for a few seconds to microscopically roughen the enamel, then rinsed and dried again.

The liquid sealant is flowed into the grooves, where it wicks into the microscopic texture, and cured with a bright light for about twenty seconds. The bite is checked and adjusted if needed. That is the entire procedure. Nothing is removed from the tooth and it is completely reversible in the sense that a sealant simply wears away if left alone.

Most sealants are resin-based. Glass ionomer sealants, which release fluoride and tolerate moisture better, are sometimes used on partially erupted molars that cannot yet be kept adequately dry, with the intention of replacing them later.

Timing matters

The first permanent molars arrive around age six, behind the baby teeth rather than replacing them, which is why many parents do not notice them coming in. The second permanent molars arrive around age twelve. Premolars erupt in between.

The ideal window for sealing is soon after a tooth has erupted far enough to be isolated and kept dry, and before decay has started. Waiting means risking that the first cavity arrives first, which changes the treatment from a five-minute coating to a filling.

Baby molars are sometimes sealed too, particularly in children with a high decay rate, since those teeth are in service until ages ten to twelve and a painful abscess in a baby molar is a genuinely bad experience.

How well they work and how long they last

Systematic reviews consistently show sealants reduce decay in the sealed surfaces of permanent molars by a substantial margin, with the largest effect in the first couple of years and meaningful protection continuing for years afterward. In children at high risk they are among the most cost-effective preventive measures available.

A well-placed sealant commonly lasts five to ten years, but it is not permanent. Partial loss happens, most often from chewing hard or sticky foods, and a partially lost sealant is worth repairing. They are checked at every routine visit, and topping one up is quick.

A common and reasonable question is whether sealing traps decay underneath. Research indicates that bacteria sealed beneath an intact sealant are deprived of nutrients and the process arrests. Nevertheless, sealants are placed on sound or very early surfaces, and anything beyond that is treated as a cavity.

Adults too

Sealants are usually discussed as a children's measure, but adults with deep unfilled grooves, a rising decay rate, dry mouth from medication, or the beginnings of demineralization in a fissure are legitimate candidates. An adult molar that has survived to forty without a filling is worth protecting.

Most dental plans cover sealants for children up to a certain age and many do not cover them for adults, which is a benefit design decision rather than a clinical one.

If you have a child approaching six or twelve, or your own molars have deep grooves you have been warned about, ask at your next visit. Call Cedar Creek Dentistry in Portland.

Questions about your own care? The team at The Best Dentist In Portland, Oregon is happy to help — call us at (503) 646-1811.

This article is for general information only and is not medical advice.