Every dentist has experienced it before. Patients refuse x-rays because they don’t want to be exposed to too much radiation. What is “too much radiation?” That’s a great question.
Medical professionals have been taught since the 1940’s that medical and dental imaging carries a tiny chance of increasing a person’s cancer risk, no matter how low the dose. The model that we were taught is called the “linear no-threshold model” (LNT) and it basically claims that any dose of radiation, no matter how small, carries an increased risk of causing cancer. As dentists, we are supposed to weigh this tiny (but not zero) increase in risk against the benefits of whatever x-ray image we wanted to see.
New research published in the American Journal of Clinical Oncology has re-evaluated the original research that we based the LNT model on and has found it to be unconvincing. The original research was performed by exposing fruit flies to various doses of radiation. The damage at each level was measured and the research made the assumption that there is no completely risk-free level of radiation.
In the LNT model, the well-established cancer-causing effects of high doses of radiation are extended downward in a straight line to very low doses. The LNT model assumes there is no safe dose of radiation, no matter how small. However, the human body has evolved the ability to repair damage from low-dose radiation that naturally occurs in the environment.
Basically, the radiation doses that were studied in the 40’s were much to high to extrapolate into low dose medical uses of radiation. We’ve based our concerns about x-ray radiation on doses that are much higher than those experienced by patients. The recent paper was specifically about CT scans, which actually have a much higher exposure to radiation than dental x-rays.
As a profession, dentistry has gone out of its way to expose patients to as little x-ray radiation as possible. But many patient still balk. The effectiveness of x-rays for dental diagnosis cannot be underestimated. But not only are they effective, current research suggests that they are completely safe.
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Joint replacement surgery changes lives. For some people having a knee or hip replaced can end years of pain and struggle. The procedure has become quite common and many dental patients in our office have had it done.
Orthopedic surgeons and dentists have been telling themselves and their patients a story about artificial joints and the risks involved with dental treatment after having one. The story goes kind of like this:
Dental treatment causes oral bacteria to get into the bloodstream. These bacteria find their way to artificial joints and if they do, they can get horribly infected. Sometimes the infection can cause the artificial joint to become so bad that it fails and needs to be replaced. This is a serious and expensive side effect. The solution to this problem is premedicating with an antibiotic before you have any dental work done. That will make it so any oral bacteria that make it into the bloodstream are killed off before they can get to the artificial joint.
At first glance, this story makes sense. You definitely don’t want an artificial joint to become infected. Since we know that dental work can cause oral bacteria to get into the bloodstream, having dental work is clearly the problem. Right?
Well…not really. The story might not be true. In fact, there is no scientific evidence that artificial joints are more susceptible to infection after dental work. The story seems plausible but just doesn’t line up with our available evidence.
Some would say, “the complication of an infected joint is so severe that taking a dose of antibiotics is a small price to pay to keep us safe.” It turns out that there is also no scientific evidence that taking any particular antibiotic can keep an artificial joint from becoming infected. Furthermore, it’s worth mentioning that taking antibiotics isn’t a risk-free event, either. Allergic reactions can happen even in people who have had no reactions taking the same medication in the past. On top of that, every time you take an antibiotic it affects the natural balance of all the good bugs that inhabit your body as well. If you’ve ever gotten a yeast infection after taking an antibiotic, you know exactly what I’m talking about! Furthermore, the overuse of antibiotics promotes bacteria that become resistant to the antibiotics which is bad for everyone!
So this is what we’ve been battling with in dentistry. The standard for joint premedication has been take 2000mg (2g) amoxicillin an hour prior to your dental appointment. However, it is somewhat typical for a patient who is supposed to take their premedication to forget to take it. In fact, it happens often. At least weekly in my experience. So then you try and decide whether you should send them home and reschedule their appointment, give them the premedication at the office or just skip it. We sure could use a little bit of guidance from professional organizations, right?
In 2012 the American Dental Association (ADA) and the American Association of Orthopaedic Surgeons (AAOS) published some guidelines. Some vague guidelines. Frustratingly. Vague. Guidelines. You can read about these guidelines in a blog post I wrote back in 2012. Essentially the guidelines stated that although there isn’t any scientific evidence to support the use of antibiotics prior to dental treatment in joint replacement patients, each case should be considered separately. The opinion of the surgeon, patient and dentist were essentially equally valid. There was not a strong “you should do this” or “you shouldn’t do this” attached to the 2012 guidelines.
I have been trying to explain to joint replacement patients that the evidence goes against the need for premedication. However, these patients have been taking antibiotics for their artificial joints for years and years. They have been told by surgeons, dentists, hygienists and all sorts of other health care providers that they are truly at risk if they don’t. Many patients wanted to continue the antibiotics for dental treatment “just to be sure.” And who could blame them? Many dentists weren’t willing to take the (essentially nonexistent) risk either. Our policy had been that the patient just needed to get a letter from their orthopedic surgeon stating that the surgeon felt premedication was necessary and we’d write the prescription. This was a compromise that I was willing to make so long as we were stuck with these wishy washy guidelines.
In early January 2015, the American Dental Association finally weighed in strongly on the controversy:
“In general, for patients with prosthetic joint implants, prophylactic antibiotics are not recommended prior to dental procedures to prevent prosthetic joint infection. The practitioner and patient should consider possible clinical circumstances that may suggest the presence of a significant medical risk in providing dental care without antibiotic prophylaxis, as well as the known risks of frequent or widespread antibiotic use. As part of the evidence-based approach to care, this clinical recommendation should be integrated with the practitioner’s professional judgment and the patient’s needs and preferences.”
Not perfect, but pretty good in my estimation. The factors that may require premedication now are people who have previously had complications with infected artificial joints as well as patients with immune system compromise.
There should be rejoicing in the streets! Think of how much less often patients will have to take antibiotics! But alas, I’ve already run into patients with concerns. I completely understand this because it’s tough to change what we’ve been doing for so long. For now, we’re going to talk to patients and explain that they really don’t need antibiotics. But we’ll keep in touch with their orthopedic doctors, too. Change happens slowly, but I think the new guidelines are a big step in the right direction!
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Delta Dental of Michigan just began offering a new kind of dental insurance to its employees. The insurance plan is being sold as “personalized care.” What a great service! They care about you as an individual! They actually test your genetic code to determine the best treatment for you, right? Well…sort of. Here’s a short version of how it works.
How the new “personalized dental insurance” plan works
Adults will be given a baseline level of preventive coverage. This baseline includes one “cleaning” and two exams covered by insurance per year. Additional “cleanings” will be covered (a maximum of four) if you have one or more risk factors. The new program includes the following risk factors:
history of heart attack/stroke
suppressed immune system
history of radiation of the head and neck due to cancer
a history of a periodontal disease/past periodontal disease treatment
Furthermore, a subscriber to this insurance policy may choose to have a genetic test done for the “periodontal disease gene.” If they test positive for this gene, they may qualify for more “cleanings.”
You may be wondering why I’m putting quotes around the word cleaning in the previous paragraphs. It’s because I kind of hate the term “cleaning.” It means different things depending on the patient’s gum (periodontal) health. So let me clarify. If you’re a healthy adult patient with no periodontal disease, you’ll most likely get a dental prophylaxis. This consists of a hygienist or dentist removing plaque and tartar that his harder to reach by regular home care as well as the crowns of your teeth polished. That’s the smooth and minty feeling you get after they finish up. If you have periodontal disease, which is to say that you’ve lost some supporting bone around your teeth, your cleaning is actually considered periodontal maintenance. This assumes you’ve had periodontal therapy (deep cleanings, aka: scaling and root planing). This is a much more in depth removal of tartar which may include local anesthesia and localized deep cleanings on the roots of the teeth. However, both of these things are (erroneously) being referred to as a cleaning, even though there are very specific insurance codes for each type.
At first glance, this really does seem like dental insurance providing true personalized care. Delta Dental of Michigan designed the plan based on some recent research from the University of Michigan that may indicate that 2 preventive visits to the dentist each year are no better than one at preventing disease.
Delta Dental seems to be indicating that this new, evidence based plan that treats patients based on their risk factors for disease is the way to go. I am very interested in letting good scientific evidence help guide the way we treat patients. I think this is in everyone’s best interest. That said, I think this plan is premature at best and disingenuous at worst. I think Dental Dental’s foray into personalized care is heading in the wrong direction for several reasons.
Weird Science: The new insurance policy is based on a University of Michigan study called “Patient Stratification for Preventive Care in Dentistry.” The study was designed to see if two recall appointments (“cleanings”) were better than one. The results would lead one to believe that two cleanings are no better than one. From what I can tell, this is the entire basis for reducing the number of baseline “cleanings” the patients with this insurance policy would receive. But there is a problem with this research. The outcome that the study measured was “tooth loss.” Which is to say, two cleanings is no better than one cleaning if your only concern is losing teeth to periodontal disease. Losing teeth due to gum disease is clearly a huge concern, but there’s a lot of other concerns (gingivitis, tooth decay, crooked teeth, tooth wear and dry mouth to name a few) that this research doesn’t address. “Tooth loss from periodontal disease” is a pretty blunt measure of whether 1 or 2 cleanings per year is better. It seems to me that most patients aim higher than just not losing teeth to gum disease.
No smoking?: Delta Dental listed many risk factors that they take into consideration when allowing for added “cleanings.” Diabetes, history of stroke/heart attack, suppressed immune system and even a genetic predilection toward gum disease. What didn’t they list? Smoking. Many believe that smoking is perhaps the most relevant risk factor of all when it comes to gum disease. Yet Delta Dental doesn’t list this as one factor that might qualify a patient for more covered recalls? What is that all about? Is it a moral stand against smoking? Whatever it is, they’re ignoring perhaps the most important factor in the development of gum disease. Since the new policy is based on research that judges tooth loss by gum disease, it seems that Delta Dental is picking the risk factors that benefit their bottom line more than the patients they serve.
What about tooth decay?: As I mentioned before, this research measured tooth loss due to gum disease. The elephant in the living room is the fact that they didn’t mention risk for tooth decay. Gum disease is common, but not nearly as common as tooth decay. For people with a lot of risk factors for decay (dry mouth, lots of medications, diet, soda consumption, poor home care), 6 months is probably too long to go without being seen by a dentist. For these folks, a year is practically a lifetime! Tooth decay can proceed very quickly in a high risk patient, yet they may not test as high risk for gum disease, which means that under a plain like this, they would likely only have one “cleaning” per year. While cleanings may not directly affect tooth decay, the fact that the patient is presenting to the dental office means that the dental team is much more likely to catch problems (e.g–cavities) while they are small and easier to treat.
You might be thinking, “O.K. Doc. I hear you. But you’re missing the point. The insurance policies still pay for two exams per year. I can come in to see you twice and you’ll still get a chance to evaluate my teeth. Even though they won’t be as smooth and minty as before, I’m still getting all that preventive benefit. I think this is really about dentists losing all that revenue from cleaning teeth. So just pipe down.”
Honestly, this is a semi-reasonable argument. The insidious part is what the insurance companies know that regular folks don’t think of. Whether you want to believe it or not, we human beings are driven by incentives. As much as I like to think that I can teach all patients about their needs, I’m still almost always limited in my treatment options by what the insurance will cover. Patients with insurance like to use their insurance benefits and they take seriously the limits that insurance policies place on them. If a patient has been used to coming every 6 months for a cleaning ever since they were a child, how likely are they going to set up for that second examination if they don’t get a cleaning? I can see it now: “So you want me to miss work so I can come over here and have you look at me for 15 minutes? I don’t get to spend quality time with April or Tanna gently polishing the plaque off my teeth? All I get is Doc shining that bright light in my eyes? Well, thanks but no thanks. I’ll pass until my next cleaning is covered.”
I’ve written previously that cleanings are overrated. Apparently the insurance companies are beginning to agree with me. I hope I’m wrong.
Did you find this post ominous? Perhaps a bit scary? This dentist in Saginaw, MI would love to hear about it! You can share any Mead Family Dental post with a “Like” on Facebook, a “+1″ on Google+ or you can even “Tweet” it with Twitter! All you need to do is hover over the heart shaped button next to the title of the post. Or you can leave a comment by clicking on the balloon shaped icon next to the title.
If you’re looking for a Saginaw dentist, we’re always happy to accept new patients! You can request an appointment online or call the office at (989) 799-9133. And, as always, you can email me at firstname.lastname@example.org. I always answer my own emails!
You brush your teeth to get the plaque off of them, right? And if you remove the plaque then you won’t get cavities, right?
The model dentistry has been explaining to patients forever is that plaque causes cavities and that if you can just remove the plaque then you’ll have healthy teeth. Unfortunately, it’s really not that simple.
Unless you’ve just had your teeth cleaned, like 2 minutes ago, your teeth are actually covered in a biofilm. It happens if you brush three times a day and floss like a maniac or if you haven’t seen a toothbrush in years. Biofilms form on most any surface that’s wet. Slime on the hull of a boat, coated rocks in a stream and the plaque covered surface of teeth are all examples of a biofilm.
Biofilms are actually microscopic communities of bacteria and the slimy matrix they make to stick to surfaces. A biofilm will “mature” over time and then spread. The plaque that dentists and hygienists talk about is actually a biofilm that’s large enough to be seen with the naked eye. Dental plaque/biofilm is actually made up of many types of bacteria. Some of the bacteria (Streptococcus mutans, for instance) found in this biofilm are the bad guys that can eat sugar and turn it into acid which can then cause tooth decay. Other bacteria (Streptococcus sanguinis) found in the plaque are actually known to make the biofilm less hospitable to the acid loving bacteria. So it doesn’t necessarily follow that biofilm = cavities. Someone who does a good job of brushing and flossing will generally keep the size of the biofilm smaller and potentially makes the biofilm “healthier” by increasing the % of bugs that don’t produce acid.
less beautiful and more common biofilm
O.K. Doc…I’m following you. Not all plaque is bad plaque. So why can’t they get rid of the bad bugs and leave the good bugs? Well, I’m glad you asked! There was a preliminary study out of UCLA about a mouth rinse that can do just that! Since it’s a preliminary study that means that real clinical trials to prove efficacy haven’t been done. They have some promising results on a small group of patients treated with a mouth rinse that can supposedly target S mutans (the bad bugs) in the plaque. According to one article there will be clinical trials starting in 2012.
If you like this post, I’d love to hear about it! You can share any Mead Family Dental post with a “Like” on Facebook, a “+1” on Google+ or you can even “Tweet” it with Twitter! All you need to do is hover over the heart shaped button next to the title of the post. Or you can leave a comment by clicking on the balloon shaped icon next to the title.
If you’re looking for a dentist in Saginaw, we’re always happy to accept new patients! You can request an appointment online or call the office at (989) 799-9133. And, as always, you can email me at email@example.com. I always answer my own emails!
This research was a literature review or a "study of studies." Many of these studies had hypothesized that there was a causative connection between asthma and tooth decay but data didn't support this hypothesis.
Inhalers used in the treatment of asthma can cause a dry mouth. Dry mouth is a major risk factor for tooth decay. To be clear, this research determined that having asthma isn't a risk factor for tooth decay, but using inhaler medications is a risk factor for dry mouth and dry mouth is a risk factor for tooth decay. If you use inhalers I would recommend chewing sugarless gum after their use to bump up your saliva flow. Along with regular brushing and flossing these precautions should help protect you against any drying that might occur from this medicine.
Do you have dental topics you'd like me to research and discuss? I'd be happy to! Feel free to drop me an email at firstname.lastname@example.org. I take requests!