Dentinal hypersensitivity is a diffused problem that patient complain about, usually associated with exposed tooth root surfaces. Any age patient can be affected (20–50 years, with a peak between 30 and 40 years of age 11) and most of the times is present on the canines and premolars of both the arches. A slightly higher incidence of sensitivity is reported in females than in males. It is clinically described as an exaggerated response to application of a stimulus to exposed root surface (dentin). Dentin hypersensitivity is characterized by short-lasting, acute pain arising from exposed root or dentin in response to insults that most of the time is thermal (cold or hot food/drinks). Direct pressure on the exposed dentin or substances may trigger this sharp pain too (Dentin hypersensitivity: Recent trends in management Sanjay Miglani, Vivek Aggarwal, and Bhoomika Ahuja J. Conserv Dent. 2010 Oct-Dec; 13(4): 218–224).
The identification of this condition can be obtained by clinical examination. Some patient self report to the dentist this condition due to its severity. A simple clinical method that the dentist can use includes a jet of air or using an exploratory probe on the exposed dentin, examining all the teeth in the area in which the patient complains of pain (Gillam DG, Orchardson R. Advances in the treatment of root dentin sensitivity: Mechanisms and treatment principles. Endod Topics. 2006;13:13–33). The severity of pain can be quantified either according to categorical scale (i.e., slight, moderate or severe pain) or using a visual analogue scale (Orchardson R, Gilliam D. Managing dentin hypersensitivity. J Am Dent Assoc. 2006;137:990–8).
Fig 1. Patient presenting with gingival recession, root exposure and subsequent dentinal hypersensitivity on canine and first premolar. The cause of this situation was attributed to heavy tooth brushing with hard bristles and use of abrasive toothpaste.
The cause of dentinal hypersensitivity can be found in incorrect and too aggressive tooth brushing, poor oral hygiene, gingival recession caused by other dental therapies (i.e. periodontal treatment, dental bleaching). Incorrect tooth brushing includes hard brushes, excessive forces associated with the use of abrasive toothpaste, excessive scrubbing at the cervical areas or even lack of brushing which causes plaque accumulation and gingival recession (Suge T, Kawasaki A, Ishikawa K, Matsuo T, Ebisu S. Effects of plaque control on the patency of dentinal tubules: An In vivo study in beagle dogs. J Periodontol. 2006;77:454–9).
The first approach is to teach the patient the correct method of tooth brushing to avoid further extension of gum recession and dental wear at the gingival level. Highly abrasive tooth powder or pastes should be avoided (Orchardson R, Gilliam D. Managing dentin hypersensitivity. J Am Dent Assoc. 2006;137:990–8). Also, the patients should be instructed to avoid brushing for at least 2 hours after acidic drinks to prevent agonist effect of acidic erosion on tooth-brush abrasion (Dentin hypersensitivity: Recent trends in management Sanjay Miglani, Vivek Aggarwal, and Bhoomika Ahuja J. Conserv Dent. 2010 Oct-Dec; 13(4): 218–224).
Erosive agents (carbonated drinks, citrus fruits, wines, yogurt and cosmetic products) are also important in initiation and progression of this condition. They act by thinning the superficial layer of teeth (cementum on the roots and the enamel on the crown) and exposing the most porous part of them (dentin) (Eisenburger M, Addy M. Erosion and attrition of human enamel In vitro. Part I: Interaction effects. J Dent. 2002;30:341–7. Osborne-Smith KL, Burke FJ, Wilson NH. The aetiology of the non-carious cervical lesion. Int DentJ. 1999;49:139–43). Dietary counselling should be suggested. Other sources of acid come from gastroesophageal reflux or regurgitation (patients with eating disorders too). A medical consult should be requested from the dentist. By removing the causative factors or limiting them, the condition can be prevented or at least limited.
As far as treatment, the severity of the condition may dictate a more invasive intervention rather than topical solutions. The patient can correct their faulty habits by utilizing some desensitizing agents (fluorides toothpastes with 5% potassium nitrate and 0.454% stannous, mouthwashes or chewing gums) and modifying their predisposing diet. Professional treatment includes topical application of agents that can cover the porosities of the teeth and block nerve triggering (0.4% stannous fluoride along with 0.717% of fluoride can provide an immediate effect after a 5 minute professional application) (Thrash WJ, Dodds MW Jones DL.
The effect of stannous fluoride on dentinal hypersensitivity. Int Dent J. 1994;44:107–18), restorations to cover exposed tooth surface that is creating sensitivity, root coverage in terms of gingival augmentation to replace or augment the tissue lost during the development of hypersensitivity.
-By Lorenzo Mordini DDS, MS
