Dentin hypersensitivity relief: getting to the root of the problem

June 22, 2021

Welcome to our series of open conversations with leading experts from the oral care field, dedicated to oral health challenges through different life stages. After the webinars on the specific oral needs of the pregnant woman, the child and the teenager, the 4th edition, streamed on June 3rd 2021, tackled dentin hypersensitivity as a condition that may come along with the new challenges of young adulthood. To get to the root of the problem, we asked Dr. Reena Wadia and Dr. Joon Seong, to share their thoughts.

The definition

The most common definition of dentin hypersensitivity is by Holland et al. in 1997. “Dentin hypersensitivity is characterized by a short, sharp, pain arising from exposed dentin in response to stimuli, typically thermal, evaporative, tactile, osmotic or chemical. The key component of the definition which is important to emphasize is that it cannot be ascribed to any other form of dental defect or pathology”, Dr. Wadia defines. Dr. Seong reminds that even a small amount of exposed dentin, often at the cervical margin of the tooth, can cause quite a lot of sensitivity. Dentin hypersensitivity affects the quality of life of the patients daily, as shown by many studies with good-quality evidence.

Dentin hypersensitivity is a short, sharp pain that can come from the smallest dentin exposure.

The Prevalence

In a 2010 large-scale prevalence study on young adults from 7 different European countries, for which Dr. Seong collected the data for UK, prevalence came out to be about 42%. About 28% had a mild tooth wear according to the BEWE index and 3% had a severe tooth wear. All the patients with periodontitis have sensitivity, whether that’s before, due to periodontitis and root exposure, or after the treatment. Sometimes patients may just think dentin hypersensitivity is something they have to deal with and tolerate. “Given it is so common and that we can help, we should be asking all of our patients if they have sensitivity”, recommends Dr. Wadia.

Dentin hypersensitivity is very common but sometimes overlooked.

The differential diagnosis

Making the correct diagnosis is of course key before jumping into treatment. Dentin hypersensitivity is a diagnosis of exclusion, once you’ve looked at everything else: cracked tooth, defective restoration margin or caries etc. Tooth wear, root exposure and acidic diet are all clues for dentin hypersensitivity.

The etiology and risk factors

“There are 2 components to understand dentin hypersensitivity and therefore, its treatment: lesion localization and lesion initiation”, Dr. Seong explains. Lesion localization means that dentin must be exposed, by loss of soft tissue which can happen from periodontal disease or also, in young adults, from orthodontic treatment with the combination of roots sitting close to the buccal plate and brushing of the braces. However, on its own, exposed dentin doesn’t cause hypersensitivity. There must also be a lesion initiation: the tubules must be patent and open, which comes with the acidic challenge. Intrinsic acid and more largely dyspepsia (which refers to upper gastro-intestinal symptoms present for more than 4 weeks and any abdominal pain or discomfort, heartburn, acid reflux, nausea, vomiting) is becoming more and more of an issue in the UK. “Patients sometimes don’t even know they have heartburn or gastric reflux but if we see signs of it in specific areas like palatally on the upper teeth, we may need to work with the medical professionals and refer to the general practitioner. Nowadays, it’s about treating the patients holistically and working with a multidisciplinary team to tackle their issues”, says Dr. Wadia.

Dentin hypersensitivity occurs when there is lesion localization and lesion initiation.

The at-home treatment

It needs to be stressed out that dentin hypersensitivity is effectively preventable. And its prevention is more important than its management.

Indeed, messages from general health professionals includes consumption of 5 or 7 portions of fruit and vegetables a day. Since 1980, there has also been a 3-fold increase in the intake of soft acidic beverages and an increase of portion sizes. With the change in diet, we are likely to see a rise in the incidence of dentin hypersensitivity. For this reason, it is important to employ preventative strategies for all the patients.

Treatment is then a stepwise approach. The 1st line of management is toothpastes used at home.

As the hydrodynamic theory describing the fluid movement in the tubules which then causes sensitivity is still the most widely accepted, there are 2 ways of managing dentin hypersensitivity: nerve desensitization or tubular occlusion. Nerve desensitization traditionally uses potassium-based toothpastes. Although clinical research evidence show they work, no one really knows how they work. The fluid coming out of the dentin tubules, it’s difficult for the potassium ions to enter and concentrate in there. Nowadays the more widely accepted approach is tubular occlusion, using toothpaste with strontium acetate, stannous fluoride, potassium oxalate, calcium sodium phosphosilicates or arginine. “To claim they are clinically proven, toothpastes actually need to be evaluated in randomized control trials assessing the patient pain score (using an ice probe), the dentist perception of patients’ response to pain (using the Schiff scale index) and the response to a tactile stimulus (using a Yeaple probe, a sharp weighted electromagnetic tool). When the 3 correlates, it is then statistically significant”, informs Dr. Seong.

Treatment is a stepwise, tailored, life-long approach for nerve desensitization, tubular occlusion or coverage of the exposed dentin, alongside simple clinical tricks and advice.

Dr. Seong tends to tell the patients to try different toothpastes out and see which one works best for them. Dr. Wadia adds: “It is really important we give the right advice as well: patients should continue to use it long term in order not to reduce the effects. And simple advice like not rinsing out after brushing otherwise it is going to be washed away may be obvious to us but not for the patients”.

The professional treatment and clinical tips

If toothpastes aren’t effective, professionally applied products come next: bonding, restoration, composites, to cover the exposed dentin. There are other proposed treatments like lasers, but according to our experts, there is a lack of evidence regarding their efficacy. From what Dr. Seong saw, when you expose dentin to laser, it can actually burn and close the dentin but the peripheral portion of the dentin that is not hit by the beam could actually be opened up even more, which means that the dentin hypersensitivity symptoms could be far worse.

After treating perio patients, Dr. Wadia likes to apply an air-polishing treatment, tubule-occluding paste on the teeth or foam trays with high fluoride. She also shared her experience from her own periodontal referral clinic: “When patients are in the chair for a periodontal maintenance appointment, it is a tricky situation trying to treat them if you don’t want to numb them up with local anesthesia. But there are simple tips and tricks, like rubbing prophylaxis paste on the tooth to block the tubules enough time to carry out some simple supra-gingival professional mechanical plaque removal. We need to show our patients that we care and make sure they are comfortable and feel heard otherwise they end up leaving having a terrible experience. People who have sensitivity are on edge all the time because they are waiting for that short sharp pain. Anxiety management is also important. It is important to remember the psychological dimension.”

The experts also answered a couple of questions from the audience. Varnishes with high fluoride can be used for immediate relief. However, although the fluoride physically blocks the tubules quite quickly, the blockage is not robust enough. For any kind of treatment modality to work, the layer must be robust against the acidic challenge that the patients bring to their teeth. “At a microscopic level, many varnishes come off straight away after treatment with an acid. There are other oxalate-based varnishes that form a crystallization within the dentin tubules stopping the movement of the fluid and as such, stopping the dentin hypersensitivity”, says Dr. Seong.

About power brushes, our experts say that if used inappropriately, any type of brush will cause recession and therefore sensitivity. So, dentists have to show the patients how to use a power brush properly, gently but effectively. Research even shows that a power brush is actually less likely to cause hard tissue damage or gingival recession. A toothbrush on its own does not cause any tooth wear: it is the brushing habit together with the abrasive toothpaste that causes a minimal amount of tooth wear, potentialized by a prior acidic intake. Finally, rinsing with water after an acidic intake or waiting 30 minutes after having a meal is also clinically relevant advice to give, to let the mouth rest to re-establish the correct pH because the acid lingers around in the mouth. Indeed, a study showed that treated with acid, all the calcium and phosphate ions are taken off. If left alone, the remaining scaffold will remineralize within 24 hours but if toothbrushing is done on top, the scaffold gets taken off as well and the tooth cannot remineralize back to where it was.

If you want to listen to the experts, you can watch the entire webinar here.

Make sure to catch all episodes by subscribing to our You Tube Channel. The next one will be on behavioral changes for middle-aged patient.

See you all there!