When a tooth needs a filling, it’s never just a one-shot deal. As we’ve noted before, all dental restorations eventually need further work. Even the strongest, most durable materials don’t last forever. Fillings wear down. Sometimes they leak. Sometimes they break.
And this cycle gets expensive. A 2004 report from Delta Dental’s Data and Analysis Center found that it can cost over $2000 per tooth over a lifetime. That number has surely gone up since then – and will only continue to do so.
Obviously, the best thing to do is to avoid developing caries in the first place. Next best is to catch any decay early, before the enamel becomes permanently damaged, when it may be successfully treated with such minimally-invasive procedures as ozone therapy, micro air abrasion or even simple dietary changes and supplementation.
When a filling needs additional treatment due to wear, breakage or recurrent decay, the dentist is faced with a question: Should the restoration be repaired or replaced? Which is the best option? Is one better than the other?
A study published last month in JADA aimed to find out. Its authors were “somewhat surprised” to find that repaired fillings ended up needing additional treatment more often than replaced ones. The difference was relatively small – a matter of just a couple percentage points difference – but there nonetheless.
Yet, as Dr. Bicuspid reports, follow-up treatment for repaired fillings was generally less severe than for replacements.
Only 25% of teeth with a repaired restoration required endodontic treatment or extraction after 12 months, while 42% of teeth with replaced restorations did. The study authors suggest that this is because “restorations that are replaced lose a significant amount of healthy tooth structure.”
The authors also noted several factors that made additional treatment more likely: the fillings involved multiple surfaces, were fractured, were placed by a dentist in a large group practice (vs. a solo or small group practice or public clinic) and…(drumroll)…were made of mercury amalgam.
Not only does amalgam bring the problem of toxicity. One of the basic mechanical problems with the material is that the dentist must remove so much more natural tooth structure than when placing composite. Its why amalgams also make teeth more prone to breakage to begin with.
You also have to consider how much extra trauma the tooth undergoes. As veteran biological dentist Dr. Gary Verigin explains in his invaluable article on “The Possible Adverse Effects of Veneers, Fillings and Crowns,”
When a dentist drills a tooth, heat is created from all the friction. Though it will be cooled some as water or air is applied, quite a bit of heat remains. Moreover, the spinning of the carbide- or diamond-tipped bur creates a vortex similar to a tornado. This can – and does – suck out the protein processes that are within each dentinal tubule. Such empty tubules are called dead tracts. Repeated dental treatments, such as filling or crown replacements, thus become more detrimental to pulpal health. Eventually, this tooth meets the same fate as the toxicated tooth,…leading to [the conventional recommendation for] a root canal.
And here is the key: the greater the number of restorative dental treatments, the greater the abuse of and trauma to the affected tooth – and the greater chance of its becoming a candidate for a root canal.
In other words, a dead tooth.
There’s one other lesson we can take from that JADA study: bargains in dentistry – such as the “bargain” of going to a large, corporate chain dental office where amalgam is the default material and through-put matters more than the patient-doctor relationship – aren’t always such a bargain. In fact, they can come with a very high cost, financially, physically…
Composite filling image by Albert, via Wikimedia Commons