What are pits and fissures?
When you look at your (unfilled) back teeth, you should notice hills and valleys. The hills are cusps and the valleys are fissures. Pits are simply fissures that are confined into the one spot.
Looking under a microscope, fissures extend further down than they appear to the eye. Fissures are typically finer that a single toothbrush bristle and this is where the problem lies: There is no way to clean the insides of pits and fissures. It’s not hard to imagine that oral bacteria would find this situation very satisfactory as dental plaque resides in fissures unchallenged by our routine hygiene measures of brushing and flossing.
As we now all know, sugar causes tooth decay because oral bacteria feeds on it and produces a very strong acid as a by-product. This acid eats into the tooth mineral and breaks it down, leading to tooth decay. Without sugar in the diet, none of this would be a problem. However, this is not typical for most of us and as such, pits and fissures remain one of the two most common areas where dentists detect tooth decay. The other is between the teeth, which is one reason why dentists urge their patients to floss.
What can be done?
For those of us who don’t like the idea of restricting sugar in the diet, the only other preventive step is to have a treatment called fissure sealing. This is done by first ensuring that the fissures are very clean. Stains are removed with very fine instruments until the fissures are confirmed as being free of tooth decay. Often small cavities can be spot-removed painlessly before fissure sealing, if the decay has not progressed through the enamel into the underlying dentine. A liquid resin is then bonded into the fissures and hardened using a blue curing light. Fissure sealants usually last between 7 and 10 years, and are a very affordable preventive dental treatment. Most children have fissure sealants done as a routine preventive measure (personally, I seal my children’s teeth the minute they appear). Adults often have fissure sealants done when fissures appear risky. About 20% of people are lucky and have naturally shallow fissures, which don’t decay easily and don’t require any treatment at all.