The reason(s) for tubules to be exposed or open should be assessed during a visual examination of the teeth. Additionally, a detailed dietary history should be taken. Useful diagnostic tools are the air/water syringe (thermal), dental explorer (touch), percussion testing, bite stress tests, and other thermal tests such as an ice cube, and assessment of occlusion. Since dentinal hypersensitivity is essentially diagnosed by exclusion, a comprehensive dental examination will ultimately rule out other underlying conditions for which sensitivity may be a symptom such as cracked tooth, fractured restoration, chipped teeth, dental caries, gingival inflammation, post-restorative sensitivity, marginal leakage and pulpitis. Excessive intake of dietary acids such as citrus juices and fruits, carbonated drinks, wines and ciders have been identified as potential risk factors for dental hypersensitivity.4,12,14 The dietary history provided by the patient will assist in identifying the risk factors the patient may have for tooth sensitivity. Erosion is one of the most common causes of irreversible enamel loss.15
In addition, other risk factors should be ferreted out during an examination such as toothbrush abrasion (Figure 3), chemical erosion (Figure 4), thin enamel, gingival recession, exposed dentin, and eating disorders such as bulimia. The patient will be able to assist in diagnosis by identifying the pain-inciting stimuli, i.e., thermal, tactile, etc., as well as describing the pain. The response to stimuli varies from patient to patient. Factors such as individual pain tolerance, emotional state, and environment can contribute to the variety of responses between and among patients.16
The most commonly cited reason for exposed dentinal tubules is gingival recession (predisposing factor).17 Gingival recession is the reduction of the height of the gingival margin to a location apical to the CEJ. Chronic exposure to bacterial plaque, toothbrush abrasion, abfraction, gingival laceration from oral habits such as toothpick use, excessive flossing, crown preparation, inadequate attached gingiva, inadequate labial plate of the alveolar bone and gingival loss secondary to disease or surgery are some but not all causes of gingival recession.17 Recessed areas may become sensitive due to the loss of cementum, ultimately exposing dentin. Probing depths, recessed areas (areas of gingival recession), and sensitivity reported by the patient must be accurately recorded and monitored to provide a reference for the patient’s disease activity over time. By removing the etiology of DH (for example, over enthusiastic brushers, periodontal treatment patients, bulimics, people with xerostomia, high acid food/drink consumers, chewing smokeless or snuff tobacco) it can be prevented from occurring or reoccurring.