Fwigures suggest that up to 69 per cent of the population will experience sensitivity at some time, while for patients with periodontal disease and/or its treatment that figure rises to 98 per cent.
Sometimes a patient will report sensitivity without prompting, but there may well be many patients suffering in silence. As many as 91 per cent of sufferers have reported that they think sensitivity is a normal part of everyday life.Because of this clinicians may want to consider adding some questions to their usual list of important topics to be discussed during check-ups and treatment appointments, to encourage patients to share information about any such discomfort.
Published material suggests: “To obtain a conclusive diagnosis of DH [dentine hypersensitivity], first carefully evaluate, investigate and compare among the other teeth, in order to eliminate other possible causes of pain, which could lead to confusion. A good clinical history is essential and questions asked by the professional may help to collect important information that will help in treatment.”
Some of the conditions that can present symptoms similar to those linked with dentine sensitivity include:
- Fractured restorations
- Acute hyperfunction of teeth
- Atypical facial odontalgia
- Congenitally open cementum-enamel junction.
Reaching a diagnosis of dentine sensitivity can be challenging, which is why it is suggested that clinicians should start by excluding the possibility that the discomfort is being caused by some other condition.
The hydrodynamic theory
The most widely accepted mechanism of dentine sensitivity is the hydrodynamic theory proposed by Brännström, “whereby fluid flow within the dentinal tubules is altered (increased or changed directionally) by thermal, tactile or chemical stimuli near the exposed surface of the tubules.”
This movement activates the nerves at the inner ends of the dentine tubules or the outer layers of the pulp. Therefore, one of the greatest risk factors for sensitivity is exposed dentine with open tubules.
Reviews have identified various processes leading to the exposure of the dentine. One of them suggested that exposed dentine can occur as a result of “denudation of the root surface due to loss of cementum and overlying periodontal tissues. Denudation of the root surface can be due to gingival recession increasing with age, chronic periodontal disease, periodontal surgery, and chronic trauma from patient’s habits.”
Compared with non-sensitive teeth, dentine tubules in sensitive teeth are eight times greater in number and two times larger in diameter. Combining these two factors the fluid flow in teeth may be 100 times greater.
In addition, the number and diameter of dentine tubules increase from the outer surface to the inner junction, increasing the likelihood of sensitivity worsening over time with loss of dentine.
Daily treatment
Recognising that exposed tubules may result in dentine sensitivity, a number of the treatments available to relieve associated pain work by occluding open tubules to block the hydrodynamic mechanism.
With evidence suggesting that blocking the dentine tubules may offer the greatest prospect for lasting relief of dentine sensitivity, the next step in helping patients is for clinicians to deliver expert care in the surgery – where appropriate – and to offer advice on the use of proven products to provide daily treatment at home.
For example, there are sensitivity toothpastes available that block tubules, however laboratory performance of some occluding toothpastes seems to indicate that these pastes leave a proportion of tubules un-occluded.
Further, “… superficial occlusion of tubules can be removed by daily tooth brushing, dissolution of the precipitate promoted by saliva or consumption of acidic beverages, leading to short-term desensitising effects. Effective treatment with long-term results has been related to intratubular deposition, which reduces the fluid flow rate or totally seals the tubule lumen.”
There is now a daily mouthwash featuring potassium oxalate crystal technology. These crystals are deposited on the dentine and deep inside the exposed open tubules, building with every rinse to provide deep, stable, comprehensive tubule occlusion.
Talking
Communication is the key to success. Asking the right questions and listening to the answers, and then ensuring you have understood the issues correctly, are necessary first steps in dealing effectively with a patient suffering discomfort that might be caused by dentine sensitivity.
Dentine sensitivity poses challenges for both the dentist and the patient, but this can be eased using a partnership approach. Clinicians may want to consider talking to patients about the whys and wherefores of dentine sensitivity, applying professional treatments in the surgery and recommending clinically-proven products for use at home to build trust and help patients become – and remain – pain-free.
References available on request.