Twenty-one root canal preparations.
And in each and every case, each and every dentist drilled a larger hole than needed.
That was the shocking result of a study published late last month in PLOS ONE. The problem, lead author Robert O’Shea explained, is caused by an “optical illusion which makes a small enclosed area (the decay) appear larger when surrounded by a larger area (the tooth).”
“The critical aspect for the illusion is the ratio between the size of the tooth and the size of the small area.
“We think that dentists think, either consciously or unconsciously, after they have made a hole of a particular size: ‘That looks rather small – I need to make that hole bigger’.”
The full study is available here.
Such research provides a powerful reminder of why we feel a conservative approach to dentistry is so important.
After all, the best teeth are the ones you were born with. Yes, there are excellent restorative materials available – strong, durable and aesthetic – but none of them can compare with natural tooth structure.
Even when a tooth shows signs of decay, the goal should be to preserve as much natural structure as possible. It’s why we generally avoid placing bridges, as most types require sacrificing parts of two healthy teeth to anchor an artificial tooth between them. It’s why we rely on technologies like Diagnodent, Spectrum, micro air abrasion and ozone – to spot and treat problems in their earliest stages.
For as we wrote before,
although a tooth may look densely solid and lifeless, it is, in fact, a living organ. Its hard outer layer of enamel protects the delicate tissues, blood vessels and nerves within. Between this pulp and enamel lies the dentin, which consists of about three miles of microscopic tubules – in each tooth! (This is why root canal therapy can never completely disinfect a tooth: It is physically impossible to thoroughly and permanently disinfect the tubules.)
That dentin, moreover, is part of your teeth’s natural defense system – obviously, something you want to keep healthy and whole.
Another recent study – this one published in the Journal of the American Dental Association (JADA) – lends further weight to the imperative for taking a conservative approach when it comes to at-risk teeth.
This one looked at the survival rate of implants versus natural teeth at risk of loss due to advanced gum disease. Adequately cared for, natural teeth fared much, much better. The loss rate for these teeth ran as high as 13.4%. The high end failure rate for implants? Thirty-three percent.
The results of this systematic review show that implant survival rates do not exceed those of compromised but adequately treated and maintained teeth, supporting the notion that the decision to extract a tooth and place a dental implant should be made cautiously. Even when a tooth seems to be compromised and requires treatment to be maintained, implant treatment also might require additional surgical procedures that might pose some risks as well. Furthermore, a tooth can be extracted and replaced at any time; however, extraction is a definitive and irreversible treatment. [emphasis added]
Our job is to help you keep your natural teeth for a lifetime. The more aggressive the dentistry – and, we might add, the less concerned with its effects on the body overall – the worse the odds of success.
Image by Gleam, via Wikimedia Commons