HAVE you ever experienced dental pain when you eat or drink anything sweet or sour, or when the food is hot or cold? It is a common occurrence and most people that this has happened to will describe it as a “shocking” pain.
If the answer is yes, then you are among the 60,000 Guyanese adults who suffer from dentine hypersensitivity.

Dentine is a mineralised tissue transected from pulp chamber (at the centre of the tooth) to enamel or cementum by minute tubules. Within the tubules are protoplasmic projections (‘tentacles of cells) with the cell body itself being located in the pulp chamber. Stimulating these cells emits one sensation, pain.

There are currently four hypotheses of pain transmission through dentine, of which the hydrodynamic theory is the most widely accepted. According to this theory, the movement of fluids within the dentine and pulp stimulates the nerves causing pain. All external stimuli translate into hydrodynamic changes that alter the pupal equilibrium and elicit pain.
Pain can be caused mechanically, chemical, thermal (temperature) or bacterial, stimuli. Stimulation sources may include tooth brushing, digital (finger) probing, desiccation (a blast of air), acids, sweet, sour, hot and cold products and acids products from plaque bacteria.

There are varied predisposing factors to dentinal hypersensitivity, but no single cause. The tooth becomes sensitive after enamel loss or root surface exposure. Enamel loss follows mechanical wear (biting surface wear), neck abrasion or possibly both flexures after grinding, which fractures enamel rods or chemical erosion (acid foods or stomach regurgitation). Gingival recession (retracting gums) and subsequent tooth root exposure allow more rapid and extensive exposure of dentinal tubules because the cementum layer overlying the root surface is thin and easily removed.

The many causes of gingival retraction include normal aging, chronic periodontal disease, abnormal tooth position in the dental arch, periodontal surgery, incorrect tooth brushing habits and root preparation for crowns. All of the precipitating factors allow the exposure of dental tubules which create the conditions for dentine hypersensitivity.

Treatment modalities fall into two main categories: chemical and physical. All available treatments work to differing degrees depending on the treatment and severity of the patient’s hypersensitivity. Pain is extremely subjective so that effective treatment often depends on the individual’s pain threshold. Some agents can be used at home; others require a visit to the dentist.

Chemical desensitising agents can be sub-classified by their action, anti-inflammatory, protein precipitating and tubule blocking.
Corticosteroids, one of the many groups of chemical agents, have been used topically for their anti-inflammatory effects, but are not particularly effective.

The second group of chemical agents, the protein precipitants, includes silver nitrate and zinc chloride. Silver nitrate was widely used in the past. Unfortunately, both substances cause teeth to stain permanently and are harmful to the gums and pulp.

Strontium chloride and formaldehyde (in Sensodyne) belong to the group of agents that precipitate proteins within the tubule. Other drugs used to treat the condition include calcium hydroxide, fluoride, and sodium citrate. Patients may also be treated with composites (fillings), resins, varnishes, sealants, soft tissue grafts, glass ionomer cement and laser sealing of tubules