Prof. Nicola West is a senior lecturer and honorary consultant in restorative dentistry (periodontology) at the Bristol Dental Hospital and School. Prof. West leads the Clinical Trials Unit team in the Bristol Dental Hospital, working closely with industry sponsors and university colleagues in the fields of dentine hypersensitivity, tooth wear, oral healthcare products, bleaching, staining, plaque, and gingivitis.

FDI recently spoke with Prof. West about one of her specialties, dentine hypersensitivity. Read on for an excerpt of our conversation.

What is dentine hypersensitivity? What are the main causes of it?

Dentine hypersensitivity occurs on areas of teeth where the exterior surface—enamel or cementum—has worn away, the underlying dentine is exposed, and crucially, the tubules within the exposed dentine are open from the oral surface to the dental pulp. Sensitivity in the form of a short lived but intense pain is experienced in these areas when they are exposed to a stimulus such as cold air or ice, sweet or sour stimuli, or touch or pressure, for example, from a toothbrush.

Dentine hypersensitivity is a two-stage process. Firstly the dentine must be exposed and then, secondly the dentine tubules must be opened. Dentine exposure typically occurs following habits that cause tooth wear, where a combination of abrasive and erosive insults result in enamel loss and/or gingival recession, which is accompanied by the loss of cementum covering the tooth root. Periodontal diseases occurring as a result of the body’s inflammatory response to plaque biomass accumulation, are initiated by gingivitis and then potentially progress to periodontitis, with bone loss and eventually tooth loss. This can lead to the exposure of dentine on the tooth root as the gingivae recede and cementum is worn away. Then, the tubules in exposed dentine are opened by exposure to acids, mostly arising through diet.

How does dentine hypersensitivity affect our quality of life and well-being?

The pain for many individuals with dentine hypersensitivity is intense, so even though it may be short-lived, affected individuals take steps to avoid it. As it is most commonly triggered by cold stimuli, this can mean avoidance of much loved foods such as ice-cream, but also in the winter the need to cover the mouth to protect the teeth from cold air. Similarly, triggers from sweet or sour foodstuff and beverage can lead to avoidance, and negatively impact quality of life.

Cold and pressure stimuli by, for example, tooth brushing or professional cleaning by an oral healthcare professional, can result in dentine hypersensitivity. If these activities are avoided, oral health will deteriorate with resultant increases in dental caries and periodontal diseases, which if untreated can lead to tooth loss. As well as having a negative impact on quality of life, periodontal diseases are also associated with a growing number of inflammatory diseases such as endocarditis and Alzheimer’s disease, thus negatively affecting general health and well-being. My research team is currently investigating the links between Alzheimer’s disease and periodontitis.

What can oral health professionals do to prevent or manage dentine hypersensitivity in their patients? What can patients do to manage this condition at home?

The prevention of dentine hypersensitivity can be achieved by educating patients about how to avoid tooth wear and periodontal diseases. This advice is provided by oral healthcare professionals who should first determine patients’ risk factors that could be contributing to these conditions and who will recommend appropriate mitigating strategies or products. However, tooth wear can be difficult to see and detect in the early stages, and dentine hypersensitivity can arise from very small lesions, particularly at the cervical margin. Oral healthcare professionals are advised to engage their patients in a conversation about dentine hypersensitivity and reassure them that effective treatment modalities are available.

To manage dentine hypersensitivity there are a range of effective over-the-counter products and professional treatments that can be applied by an oral healthcare professional. Generally, these need regular re-application. Affected individuals are advised to initially manage their condition by using a proven toothpaste formulated for dentine hypersensitivity. These formulations contain ingredients to either reduce the nerve response to the stimulus, or block the dentine tubules and have the advantage that they can be used twice-daily in the individual’s normal oral hygiene regimen. We have evaluated a number of these toothpastes and demonstrated excellent efficacy in both laboratory and clinical studies.

What are the main causes of dentine hypersensitivity?

As indicated earlier, tooth wear and periodontal diseases are the main causes of dentine hypersensitivity.

Tooth wear is a multifactorial process involving abrasion, attrition, and acidic erosive challenge. Of these three aetiological factors, acidic erosive challenge from dietary acids, such as soft drinks which may be carbonated or still (and these include fruit juices and smoothies), are key as they soften dental enamel. This increases the impact of any subsequent abrasion or attrition and opens the dentine tubules.

Periodontal diseases largely arise from poor oral health and incidence increases with age. However, genetic susceptibility is also a factor.

How widespread is dentine hypersensitivity? Do certain regions of the world have a higher incidence of dentine hypersensitivity than others?

Dentine hypersensitivity prevalence varies due to the population investigated. The most representative figures are from general dental practice data collection rather than focusing on specific groups of individuals. My research team examined over 3,000 young adults from general practice settings showing that 42% of young adults in Europe suffered from dentine hypersensitivity—that is 1 in 3 individuals. We are currently undertaking a follow-up study of 5,000 adults of all ages in 7 European countries to build on this data.

Similar studies to determine dentine hypersensitivity prevalence are being carried out in the U.S., and have been undertaken in Africa, China, and the Middle East following our European study design with variable prevalence. However, studies that have been undertaken in other regions are generally small, so a true global picture is not yet available. Global data for periodontal diseases does exist indicating that they are most prevalent in South-East Asia, and studies of periodontal patients indicate a high prevalence of dentine hypersensitivity in this population—over 50%.

Given that periodontal diseases are increasingly common with age, affecting almost 50% of adults, it is likely that figures for dentine hypersensitivity reflect these data. Dentine hypersensitivity is likely to increase in the future both in the young adult due to erosive tooth wear and the older adult from an increase in vital tooth retention, longevity of the individual, periodontal diseases, and erosive tooth wear.

Periodontal diseases and tooth wear are both, in the majority, totally preventable and need to be prevented or, if present, addressed at an early stage to reduce the lifelong effects of dentine hypersensitivity pain and improve people’s quality of life.