Dentin Hypersensitivity PDF

Lec. 5 Dentin Hypersensitivity Dr.Anas Hussien -------------------------------------------------------------------------------------------------Dentinal hypersensitivity is a common clinical condition frequently associated with exposed dentinal surfaces. It can be defines as a short-lived, sharp, lo...

Lec. 5 Dentin Hypersensitivity Dr.Anas Hussien -------------------------------------------------------------------------------------------------Dentinal hypersensitivity is a common clinical condition frequently associated with exposed dentinal surfaces. It can be defines as a short-lived, sharp, localized, transitory pain caused by the exposure of the dentin.More prevalent in patients who are between the ages of 20 and 40, and the teeth with the highest incidence are the canines and premolars on either side in the cervical region..The most common symptom reported by patient is a sharp transient pain produced by one of several different stimuli: thermal, chemical, tactile, evaporative, and osmotic. But it should be differentiated from tooth sensitivity which may elicit from other clinical conditions such as dental caries, microleakage, cracked tooth or fractured restorations. Etiology and Predisposing Factors Theories of Dentin Hypersensitivity Hydrodynamic Theory The currently most accepted mechanism of dentin hypersensitivity is the hydrodynamic theory. According to this theory, when the exposed dentin surface is subjected to thermal, chemical, tactile or evaporative stimuli, the fluid flow within the dentin tubules moves either in outward or inward direction. This fluid movement activates the mechanoreceptors present on A delta fibers. Accordingly, the number and the diameter of the dentin tubules are considered important factors in initiating pain from dentin hypersensitivity. Hence, the higher the number and greater the diameter of the open dentin tubules, the more intense will be the pain. It has been noted that triggers such as cold stimuli stimulate fluid to flow away from the pulp creating more rapid neural responses than heat stimuli, which cause somewhat sluggish fluid flow toward the pulp. This is aligned with the observation that dentin hypersensitivity patients more frequently complain of pain in response to cold stimuli than to heat. Pain produced when sugar or salt solutions are placed in contact with exposed dentin can also be explained by dentinal fluid movement. Dentinal fluid is of relatively low osmolarity, which has tendency to flow toward solution of higher osmolarity, i.e. salt or sugar solution. Diagnosis A careful history together with a thorough clinical and radiographic examination is necessary before arriving at a definitive diagnosis of dentin hypersensitivity. Identify etiological and predisposing factors, and make differential diagnosis to exclude all other dental conditions. Check for evidence of tooth wear like attrition, abrasion, erosion, gingival recession, etc. Check about the past dental treatments like vital tooth bleaching, periodontal procedures, and medical conditions that result in tooth wear like bulimia and gastroesophageal reflux disease (GERD). A simple clinical method of diagnosing dentin hypersensitivity includes a jet of air or using probe or explorer on exposed dentin in mesiodistal direction. Treatment Hypersensitivity can resolve without the treatment or may require several weeks of desensitizing agents before improvement is seen. In some cases, pain hypersensitivity is self-limiting because of decrease in dentin permeability due to following reasons: i. Formation of reparative dentin. ii. Dentin sclerosis causing obliteration of tubules by formation of mineral deposits. iii. Calculus formation on the surface of dentin. Management of dentin hypersensitivity should be initially focused on its prevention, i.e. to eliminate the predisposing factors. Prevention of dentin hypersensitivity includes: i. Ensure proper oral hygiene practice like correct tooth brushing technique, use of nonabrasive dentifrice, etc. ii. Avoid excessive brushing with excessive pressure. iii. Avoid brushing immediately after taking acidic drinks. iv. Avoid overinstrumentation of root surfaces during scaling and root planing. v. Avoid taking food causing erosive loss of tooth structure. vi. Manage patient with gastroesophageal reflux disease (GERD) by medical help, fabrication of occlusal splint so as to cover affected areas, and prevent their contact with acids. Since dentin hypersensitivity is caused by fluid movement in dentinal tubules which stimulate the peripheral nerve endings, the principal treatment options for dentin hypersensitivity are shown in Figure 27.3: 1. Occlude the dentinal tubules: It is done by a. Formation of smear layer and plugging the tubule b. Increasing formation of intratubular dentin c. Inducing formation of tertiary dentin 2. Decreasing intradental nerve excitability. Treatment Home Care with Dentifrices Dentifrices containing 10% strontium chloride or 5% potassium nitrate or sodium monofluorophosphates are effective in treating dentin hypersensitivity. Potassium nitrate acts by penetrating A delta fibers reducing their excitability. In-office Treatment procedure 1. Varnishes, Fluoride Varnish Open tubules can be covered with a thin film of varnish, providing a temporary relief; varnish such as copalite can be used. For sustained relief, a fluoridecontaining varnish (example sodium fluoride and stannous fluoride) can reduce the hypersensitivity because fluoride decreases the dentinal permeability by precipitating calcium fluoride crystals in the tubules. 2. Dentin Bonding Agents Dentin bonding agents can be applied to seal the dentinal tubules. 5% glutaraldehyde when combined with 35% HEMA causes coagulation of proteins inside the dentinal tubules. 3. Oxalates Oxalates precipitate and occlude the open dentinal tubules. They react with calcium ions of dentin and form calcium oxalate crystals inside the dentinal tubules as well as on the surface of dentin. 3% potassium oxalate reduces hypersensitivity but it should not be used for long time as it can cause gastric irritation. 4. Gingival Grafts Gingival grafts are indicated in cases where gingival recession is progressive and treatment is not responding to conventional methods. 5. Anti-inflammatory 0.5% solution of prednisolone on exposed root surface induces remineralization resulting in occlusion of dentinal tubules. 6. Fluoride Iontophoresis Iontophoresis is a term applied to the use of an electrical potential to transfer ions into the body for therapeutic purposes. The objective of fluoride iontophoresis is to drive fluoride ions more deeply into the dentinal tubules that cannot be achieved with topical application of fluoride alone. Recent Trends To Treat Dentin Hypersensitivity 1. Arginine-based product pro-ArginTM ProArgin is available as home care toothpaste that can be indicated in association with the inoffice treatment. It uses arginine, an amino acid, bicarbonate (pH buffer), and calcium carbonate as source of calcium. Its mechanism of action is based on the role that saliva plays an important role in reducing the dentin hypersensitivity. Arginine is positively charged, it binds to negatively charged tubules, thus attracting a calcium rich layer from saliva to infiltrate and block the dentinal tubules. This dentin plug is rich in phosphate, calcium, and carbonate, and reduces the flow of dentinal fluid in the tubules. It is applied by slow speed handpiece on exposed dentin. It provides the instant relief. 2. Laser The laser therapy has been proposed for treatment of dentin hypersensitivity because it is painless for the patient. Mechanisms of action performed by different types of laser are: Occlusion of dentinal tubules, for example, NdYAG. Alteration of nerve transmission, e.g. GaAlAs Deposition of insoluble salts in dentinal tubules, e.g. Er:YAG laser. Coagulation of proteins within the tubules and blocking the fluid movement. 3. Bioglass It contains calcium sodium phosphosilicate bioactive glass and comes under the trade name of NovaMin. In this, silica is the main component which acts as nucleation site for precipitation of calcium and phosphate. When applied on dentin, it forms the apatite layer which occludes the tubule. 4. Nanodentistry Nanomaterials are those materials with component less than 100 nm in dimension. Recently, nanohydroxy apatite paste technology has been developed in dentistry for the remineralization of carious lesions and treatment of dentin hypersensitivity. NanoHAP uniformly occludes the dentinal tubules with a dentinal plug and forms a protective layer on the surface of the dentine, thus reducing the dentin hypersensitivity.