Review Article Int J Clin Prev Dent 2019;15(2):73-76ㆍhttps://doi.org/10.15236/ijcpd.2019.15.2.73

ISSN (Print) 1738-8546ㆍISSN (Online) 2287-6197

Dentin Hypersensitivity: Etiology, Symptoms, Diagnosis and Recent Trends in Management

Surbhi Agarwal

Department of Pedodontics and Preventive , Teerthanker Mahaveer Dental College, Moradabad, India

Dentin hypersensitivity is dental which is sharp in nature and persist for short duration, a comes from exposed dentin surfaces in response to stimuli, mainly thermal, tactile, osmotic, chemical or electrical. The main cause of sensitivity is reced- ing with exposure of root surfaces, loss of the layer and smear layer, and . Theoretically noticed, the reported incidence is usually higher than when clinical examination is used. Overall, it is estimated to affect about 20% of the general population to some degree. The diagnosis of dentin hypersensitivity may be challenging. It is a diagnosis of ex- clusion, reached once all other possible explanations for the pain have been ruled out. There is no universally accepted, gold-standard treatment which reliably relieves the pain of dental hypersensitivity in the long term, and consequently many treatments have been suggested which have varying degrees of efficacy when scientifically studied. Generally, they can be divided into in-office, or treatments which can be carried out at home, available over-the-counter or by prescription. Non-in- vasive, simple treatments which can be carried out at home should be attempted before in-office procedures are carried out.

Keywords: Dentin, Dentin tubule, Dentin hypersensitivity, Desensitizing agent

Introduction Causes

Dentin hypersensitivity (DH [1], or DHS [2], or sensitive The main cause of sensitivity is receding gums with ex- dentin [3], dentin sensitivity [4], cervical sensitivity [5], and posure of root surfaces, loss of the cementum layer and smear cervical hypersensitivity [5]) is dental pain which is sharp in layer, and tooth wear [6]. Receding gums is because of nature and persist for short duration, acomes from exposed long-term trauma from excessive or forceful toothbrushing, or dentin surfaces in response to stimuli, mainly thermal, tactile, abrasive toothpaste brushing (dental ) [6,7], or a sign osmotic, chemical or electrical; It has been recorded for over of (gum disease) [7]. The other less com- 2 millenium. The earliest treatment method was noticed back mon causes are (may be related to gastro- to 400 B.C. (Figure 1). esophageal reflux disease orr excessive consumption of acidic foods and drinks), and periodontal root planing [7]. Other im- portant cause is Dental bleaching of hypersensitivity [6]. Corresponding author Surbhi Agarwal E-mail: [email protected] According to some it includes tobacco, which can https://orcid.org/0000-0003-3507-1370 wear down enamel and gum tissue, cracked teeth or grinding of teeth () [8]. Dentine contains many thousands of Received April 29, 2019, Revised May 27, 2019, microscopic tubular structures that radiate outwards from the Accepted June 17, 2019 ; these dentinal tubules are typically 0.5-2 µm in diameter.

Copyright ⓒ 2019. Korean Academy of Preventive Dentistry. All rights reserved. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

73 International Journal of Clinical Preventive Dentistry

Figure 1. Dentin hypersensitivity. Figure 2. Internal structure of teeth.

Changes in the flow of the plasma-like biological fluid present er stimuli may also trigger pain in DH, includes. in the dentinal tubules can trigger present • Thermal – hot and cold drinks and foods [9], cold air, cool- on nerves located at the pulpal aspect, thereby eliciting a pain ant water jet from a dental instrument. response. This hydrodynamic flow can be increased by cold, • Electrical – electric pulp testers [6]. air pressure, drying, sugar, sour (dehydrating chemicals), or • Mechanical–tactile – dental probe during dental examina- forces acting onto the tooth. Hot or cold food or drinks, and tion [6], periodontal [6], tooth- physical pressure are typical triggers in those individuals with brushing [9]. teeth sensitivity (Figure 2). • Osmotic – hypertonic solutions such as sugars [6]. • Evaporation – air blast from a dental instrument [6]. Epidemeology • Chemical – acids [6], e.g., dietary, gastric, acid etch during dental treatments. DH is undoubtedly common condition [1,5]. Various stud- The frequency and severity of pain with every stimulus oc- ies and methods for detection of DH had been done because in curs are variable [2]. differences in populations, the reported incidence ranges from 4%-74% [5]. Dentists may under-report DH due to difficulty Diagnosis in diagnosing and managing the condition [1]. Theoretically noticed, the reported incidence is usually higher than when The diagnosis of DH may be challenging [2]. It is a diag- clinical examination is used [5]. Overall, it is estimated to af- nosis of exclusion, reached once all other possible ex- fect about 20% of the general population to some degree. planations for the pain have been ruled out. Senitivity can affect people of any age, although those aged A thorough patient history and clinical examination are 20-50 years are more likely to be affected [5]. Females are required. The examination includes a pain provocation test by more likely proneto develop DH when compared to males [5]. blasting air from a dental instrument onto the sensitive area, or The condition is mostly noticed in the maxillary and man- gentle scratching with a dental probe [10]. If a negative result dibular canine (facial) and bicuspid teeth on the buccal aspect for the pain provocation test occurs, no treatment for dentinal [5], especially in areas of periodontal attachment loss [7]. hypersensitivity is indicated and another diagnosis should be sought, such as other causes of [10]. Symptoms of the dental pulp, termed , produces true hypersensitivity of the nerves in the dental pulp [5]. In respond to external stimulus that is cold pain is sharp and Pulpitis is classified as irreversible when pulpal inflammation sudden [1,9]. About 75% of people with hypersensitivity re- will irreversibly progress to pulpal necrosis due to com- porting pain upon application of a cold stimulus [5]. some oth- pression of the venous microcirculation and tissue ,

74 Vol. 15, No. 2, June 2019 Surbhi Agarwal：Dentin Hypersensitivity

Figure 3. (A) Enamel loss exposing dentin. (B) Gum loss exposing dentin.

Table 1. Kind of intended mechanism of action the long term [10], and consequently many treatments have Intended mechanism of action Examples been suggested which have varying degrees of efficacy when scientifically studied [1]. Generally, they can be divided into Nerve desensitization nitrate Glutaraldehyde in-office (i.e., intended to be applied by a dentist or dental Silver nitrate therapist), or treatments which can be carried out at home, Protein precipitation Zinc chloride available over-the-counter or by prescription. Non-invasive, Strontium chloride hexahydrate simple treatments which can be carried out at home should be attempted before in-office procedures are carried out [10]. Stannousfluoride The purported mechanism of action of these treatments is ei- Strontium chloride Plugging dentinal tubules Potassium ther occlusion of dentin tubules (e.g., resins, varnishes, tooth- Calcium phosphate pastes) or desensitization of nerve fibres/blocking the neural Calcium carbonate transmission (e.g., , , po- Bioactive glasses tassium nitrate) (Figure 3, Table 1). Dentin adhesive sealers Fluoride varnishes Oxalic acid and resin GIC In-office treatment Composites Dentin bonding agents In-office treatments may be much more complex and they Lasers Nd: YAG may include the application of dental sealants, having fillings Er:YAG put over the exposed root that is causing the sensitivity, or a recommendation to wear a specially made night guard or re- tainer if the problems are a result of teeth grinding. Other pos- and reversible when the pulp is still capable of returning to a sible treatments include fluorides are also used because they healthy, non-inflamed state, although usually dental treatment decrease permeability of dentin in vitro. Also, potassium ni- is required for this. Irreversible pulpitis is readily distinguish- trate can be applied topically in an aqueous solution or an ad- able from DH. There is poorly localized, severe pain which is hesive gel. Oxalate products are also used because they reduce aggravated by thermal stimuli, and which continues after the dentin permeability and occlude tubules more consistently. stimulus is removed. There also is typically spontaneous pain However, while some studies have showed that re- without any stimulus. Reversible pulpitis may not be so read- duced sensitivity, others reported that their effects did not dif- ily distinguishable from DH; however usually there will be fer significantly from those of a placebo. Nowadays, DH treat- some obvious sign such as a carious cavity, crack, etc. which ments use adhesives, which include varnishes, bonding agents indicates pulpitis. In contrast to pulpitis, the pain of DH is and restorative materials because these materials offer im- short and sharp. proved desensitization [11]. Low-output lasers are also suggested for DH, including Treatment GaAlAs lasers and Nd:YAG laser [7]. They are thought to act by producing a transient reduction in action potential in C-fi- There is no universally accepted, gold-standard treatment bers in the pulp, but Aδ-fibers are not affected [7] (Figure 2). which reliably relieves the pain of dental hypersensitivity in

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At-home treatments References

At-home treatments include desensitizing toothpastes or 1. Karim BF, Gillam DG. The efficacy of strontium and potassium dentifrices, potassium salts, and chewing gums. toothpastes in treating dentine hypersensitivity: a systematic A variety of toothpastes are marketed for DH, including review. Int J Dent 2013;2013:573258. 2. Türp JC. Discussion: how can we improve diagnosis of dentin compounds such as strontium chloride, strontium acetate, ar- hypersensitivity in the dental office? Clin Oral Investig 2013;17 ginine, calcium carbonate, and calcium so- Suppl 1:S53-4. dium phosphosilicate [1]. Desensitizing chewing gums and 3. World Health Organization. International statistical classi- mouthwashes are also marketed [5]. fication of diseases and related health problems- 10th revision Potassium-containing toothpastes are common; however, (ICD-10) version for 2010 [Internet]. World Health the mechanism by which they may reduce hypersensitivity is Organization [cited 2013 Dec 21]. Available from: https://icd.- unclear. Animal research has demonstrated that potassium who.int/browse10/2010/en. ions placed in deep dentin cavities cause nerve depolarization 4. National Library of Medicine. Medical subject headings [Internet]. National Library of Medicine [cited 2013 Dec 21]. and prevent re-polarization. It is not known if this effect would Available from: https://www.nlm.nih.gov/mesh/meshhome.html. occur with the twice-daily, transient and small increase in po- 5. Miglani S, Aggarwal V, Ahuja B. Dentin hypersensitivity: recent tassium ions in saliva that brushing with potassium-contain- trends in management. J Conserv Dent 2010;13:218-24. ing toothpaste creates. In individuals with DH associated with 6. Petersson LG. The role of fluoride in the preventive management exposed root surfaces, brushing twice daily with toothpaste of dentin hypersensitivity and root caries. Clin Oral Investig containing 5% potassium nitrate for six to eight weeks reduces 2013;17 Suppl 1:S63-71. reported sensitivity to tactile, thermal and air blast stimuli. 7. Hargreaves KM, Cohen S. Cohen's pathways of the pulp. 10th ed. St. Louis: Mosby Elsevier; 2010:510, 521. However, meta analysis reported that these individuals’ sub- 8. Schmidlin PR, Sahrmann P. Current management of dentin jective report of sensitivity did not significantly change after hypersensitivity. Clin Oral Investig 2013;17 Suppl 1:S55-9. six to eight weeks of using the potassium nitrate toothpaste 9. Poulsen S, Errboe M, Lescay Mevil Y, Glenny AM. Potassium [9]. containing toothpastes for dentine hypersensitivity. Cochrane Since 2000, several trials have shown that potassium-con- Database Syst Rev 2006;(3):CD001476. taining toothpastes can be effective in reducing DH, although 10. Orchardson R, Gillam DG. Managing dentin hypersensitivity. rinsing the mouth after brushing may reduce their efficacy [11]. J Am Dent Assoc Vol 2006;137:990-8; quiz 1028-9. Studies have found that mouthwashes containing potas- 11. Orchardson R, Gillam DG. The efficacy of potassium salts as agents for treating dentin hypersensitivity. J Orofac Pain sium salts and fluorides can reduce dentine hypersensitivity, 2000;14:9-19. although rarely to any significant degree [11]. As of 2006, no controlled study of the effects of containing po- tassium chloride has been made, although it has been reported as significantly reducing dentine hypersensitivity [11].

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

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