EUKVPEAN JOIIKNAI. 1)F ORAL SCIENCES
Thomas lmfeld Dental erosion. Definition, Clinic of Preventive Dentistry, Periodontology and Cariology, Dental Institute, University of classification and links Zurich, CH-8028 Zurich, Switzerland
Iinfeld T: Deiitul erosion. Dejinition, classification and links. Eur J Ortil Sci 1996: 104: 1.5-155. 0 Munksgaard, 1996.
An overview of tooth wear, i.e. of non-carious destructive processes affecting the teeth including abrasion, demastication, attrition, abfraction, resorption and erosion is presented. The nomenclature and classification of dental erosion com- Key words: abfraction; abrasion; attrition: nionly used in the dental literature are summarized. They are based on etiology demastication; dental erosion; non-carious (extrinsic, intrinsic, idiopathic), on clinical severity (Classes I to III), on patho- lesions; resorption genetic activity (manifest, latent) or on localization (perimolysis). Interactions T, Imfeld, of Dentistry, between erosion and abrasion, demastication, attrition, and abfraction as well periodonto[ogy and cariology,Dental Institute, as caries and low salivary flow rate are highlighted. University of Zurich. Telefax: +41-I2620105
material factors have been found to influence the Non-carious destructive processes involved in prevalence of abrasion. Patient factors include tooth wear brushing technique, frequency of brushing, time Different forms of chronic destructive processes spent on brushing, force applied during brushing, other than caries affecting the teeth and leading where on the dental arch brushing is started, etc. to an irreversible loss of tooth structure from the Material factors refer to type of material, stiffness external surface are described in the literature. and end-rounding of toothbrush bristles, tuft-de- They are referred to as abrasion, demastication, sign of the brush, flexibility and length of the attrition, abfraction, resorption and erosion. These toothbrush grip, as well as abrasiveness, pH and processes can be viewed as physiological and/or amount of dentifrice used. Abrasion on proximal pathological, but the literature does not give any tooth surfaces may be caused by extensive use of clear definitions when to appropriately use which interdental cleaning devices such as tooth picks or term. Non-carious loss of dental hard tissue, also interdental brushes, especially when they are in- generically termed tooth wear, is hardly ever serted along with toothpaste or toothpowder. Oc- caused by one of the above processes alone. Ac- cupational abrasion, i.e. excessive tooth wear due cording to current knowledge, tooth wear in any to any professional cause such as abrasive dust at one individual is likely to be multifactorial. the work place, holding nails between the teeth. Abrasion, derived from the Latin verb abradere, biting thread, etc. are only rarely seen today. nhrasi, ahrasum (to scrape off,), describes the wear- Demastication, derived from the Latin verb ing away of a substance or structure through me- mandere. mundi, mansum (to chew), describes the chanical processes, such as grinding, rubbing or wearing away of tooth substance during the masti- scraping. The clinical term dental abrasion or ab- cation of food with the bolus intervening between rasio dentium is used to describe the pathological opposing teeth. Wear is then influenced by the wearing away of dental hard tissue through abnor- abrasiveness of the individual food. Demastication mal mechanical processes involving foreign objects is normally a physiological process affecting pri- or substances repeatedly introduced in the mouth marily the occlusal and incisal surfaces, but may and contacting the teeth. Depending on the etiolo- be termed pathological when occurring due to ab- gy, the pattern of wear can be diffuse or localized. normal food consumption such as betel nut de- Based on the clinical observation of the frequent mastication or the like. Although the term demas- coincidence of smooth-surface and/or cervical tication is used in the dental literature, this type of abrasion and extensive oral hygiene, the latter has wear can also be looked at as a combination of been incriminated to be a main etiological factor abrasion and attrition. in dental abrasion (1). Both patient factors and The term Attrition is derived from the Latin verb uttrrrre, uttrilti, crttrituiii, describing the action of pathologic, chronic, localized, painless loss of den- rubbing against something. The clinical term den- tal hard tissue chemically etched away from the tal attrition or cittritio rieritiznii is used to describe tooth surface by acid and/or chelation without the physiological wearing away of dental hard bacterial involvement (3-5). The acids responsible tissue as a result of tooth-to-tooth contact with no for erosion are not products of the intraoral flora; foreign substance intervening. Such contact occurs they stem from dietary, occupational or intrinsic when grinding the teeth. e.g. during swallowing, sources. speech, and when lifting heavy things, and the re- The described forms of non-carious loss of sulting wear involves the occlusal and incisal sur- tooth substance are summarized in Table 1. faces of teeth. Proximal surfaces are also worn by attrition during mastication. The individual degree Nomenclature and classification of erosion of attrition is chiefly associated with age. Clinical- ly, this loss of substance mostly leads to the forma- Since the early reports on tooth erosion published tion of facets. in 1892 by DARBY(6), in 1907 by MILLER(7) and The term ..1hfi.uc.tioii. derived from the Latin in 1923 by PICKERILL(8) many differing nomencla- verb ,fiaiigerc. ,fi.cJgi.,ftuc.tuin (to break), is used to tures and classifications have been used in the den- describe a special form of wedge-shaped defect at tal literature, describing erosive lesions of the teeth. the cementoenamel junction (CEJ) of a tooth (2). The variety came about because different authors Such lesions observed on a single tooth or on chose different approaches. Thus, nomenclature non-adjacent teeth are hypothesized to be the re- and classification were based on 1) etiology, 2) clin- sult of eccentrically applied occlusal forces leading ical severity, 3) activity of progression and 4) local- to tooth flexure rather than to be the result of ization of erosion. abrasion alone. According to the tooth flexure theory. masticatory or parafunctional forces in Classification based on etiology areas of hyper- or malocclusion may expose one or several teeth to strong tensile, compressive or Tooth erosion is termed either extrinsic, intririsic shearing stress. These forces are focussed on the or itiioputhic, implying that according to the anani- CEJ. where they provoke microfractures in enamel nesis (case history taking) the acids producing and dentin. The microfractures are thought to tooth destruction may be of exogenous, endoge- propagate with time perpendicular to the long axis nous or unknown origin. of the stressed teeth until enamel and dentin break Extrinsic erosion is the result of exogenous acids. away. The resulting wedge-shaped defects have These can be airborne acidic contaminates of the sharp rims. As the scientific basis of the tooth working environment, sometimes referred to as in- flexure theory is not yet sufficiently explored, more dustrial acids (9-12), or acidic water of swimming research is needed for a better understanding of pools, a side effect of chlorination using chlorine this process. gas that reacts with water to form hydrochloric Resorption. derived from the Latin verb resorb- acid (13, 14). Severe cases of extrinsic erosion have erc' (to suck back), describes the process of biologi- also been reported owing to the oral administra- cal degradation and assimilation of substances or tion of medicaments such as iron tonics, acid re- structures previously produced by the body. The placements for patients suffering from achlorhy- clinical terms dental resorption. root resorption, dria. or acid to dissolve small renal calculi (15- tooth resorption and the like describe the biologi- cal removal of dental hard tissue by cementoclas- tic, dentinoclastic and ameloclastic activity. This Table 1 can be either a physiological process, as in the case of root resorption of deciduous teeth, or a patho- logical process such as resorption owing to trau- ma. cysts or neoplasms. Resorption is of no rele- Terminology Cause of loss of hard tissue vance in the context of erosion. but for the sake of A brasion Mechanical process involving foreign ob- completeness cannot be omitted from the list of jects or substances non-carious destructive processes. Demastication Mechanical interaction between food and Erosioii. derived from the Latin verb erotlere, teeth erosi. wuszm (to gnaw, to corrode), describes the Attrition Mechanical process involving tooth-to- tooth contact process of gradual destruction of the surface of Abfraction Mechanical process involving tooth flex- something. usually by electrolytic or chemical pro- Lire by eccentric occlusal forces cesses. The clinical term dental erosion or erosio Erosion Chemical etching and dissolution doiiiiiim is used to describe the physical result of a Resorption Biological degradation Dental erosion. Definition,clrrssificutioii 153 19). Dietary acids, however, undoubtedly are the longer subject to further decalcification, have principal causative factor for extrinsic tooth ero- prominent thick enamel borders and do not show sion (20-23). The most frequently consumed ero- a honeycomb enamel prism structure in shadowed sive acids are fruit acids and phosphoric acid con- replicas observed in the SEM (20). tained in fresh fruits, fruit juices and soft drinks (24-29). More recently ascorbic acid (vitamin C) Terminology based on localization contained in all sorts of drinks, sports drinks and candies has been identified as a significant cause of Chronic regurgitation, be it of somatic or of extrinsic erosion (20, 30-36). psychosomatic origin, often leads to a typical dis- Intrinsic erosion is the result of endogenous acid. tribution of erosion within the dental arches and This is gastric acid contacting the teeth during re- on the teeth. This clinical finding has been termed current vomiting, regurgitation or reflux. Eating perimolysis or periniylolvsis (44, 45, 54). Corre- disorders of psychosomatic origin, such as nervous sponding with the path of the regurgitated hydro- vomiting, anoresia iiervosu or bulimia (3742) are chloric gastric acid over the dorsum of the tongue, often the cause of regurgitation or vomiting which along the palatal surfaces of the maxillary teeth, in these cases is self-induced. Causes of somatic and over the occlusal surfaces into the mandibular origin include pregnancy, alcoholism (43), antabus vestibulum, perimolysis affects the maxillary and therapy for alcohol abuse (44) and gastrointestinal mandibular teeth in different ways. While affecting disorders, such as gastric dysfunction (45), chronic the palatal and occlusal surfaces of all teeth in the obstipation (46), hiatus hernia (47), duodenal and maxilla, the erosion is confined to the buccal and peptic ulcer (48) and gastroesophageal reflux occlusal surfaces of premolars and molars only in disease (49). the mandible. The buccal surfaces of the maxillary Idiopathic erosion is the result of acids of un- dentition are not contacted by the acid and are known origin, i.e. an erosion-like pathology where further protected by the neutralizing effect of the neither tests nor anamnesis are capable of provid- parotid saliva. The lingual surfaces of the mandib- ing an etiologic explanation. ular teeth are covered by the tongue and are thus also spared from the acid. Additionally they are bathed in the pooled oral fluid from the submandi- Classification based on clinical severity bular and sublingual glands. A further feature of Different classifications of tooth wear have been perimolysis is that restorations remain intact and proposed, based on visual examination of the project above the tooth surfaces. A recent study on tooth surfaces and on ascribing scores to them ac- risk factors in dental erosion (21) was, however, cording to the extent of the lesions. Few indices, rather guarded about any distinct intraoral distri- however, have explicitly aimed to assess erosion. bution of erosion in relation to etiology. In 1979 ECCLES(50) classified erosion as follows: The nomenclature and classification of erosion Class I: Superficial lesion, involving enamel are summarized in Table 2. only; Class 11: Localized lesion, 1/3 of surface involv- < Multifactorial etiology of tooth wear ing dentin; Abrasion, demastication, attrition and abfraction Class 111: Generalized lesion, >1/3 of surface in- volving dentin. The surface of erosive lesions is hypomineralized. Based on these three classes, LUSSIand co-workers Although enamel softening is not clinically detect- (51) have recently published a similar, more de- able, erosion decreases the wear-resistance of den- tailed index of erosion for epidemiologic use. tal hard tissue (55), thus rendering both enamel and dentin more susceptible to the effects of me- chanical abrasion (56). As a consequence, erosion Classification based on pathogenetic activity is in vivo frequently exacerbated by mechanical MANNERBERG(52, 53) distinguished two types of abrasion, such as toothbrushing immediately erosion according to activity, namely manifest and following an acid challenge. Erosive lesions may latent erosion. A manifest erosion, i.e. an actively also be aggravated by demastication (57), especial- progressing erosion, is clinically diagnosed by its ly in lactovegetarian patients (58), by attrition of enamel border zones. These are thin where they incisal edges and cusps or possibly by abfraction meet the exposed dentin. In the scanning electron at the cementoenamel junction. A clinical es-posr microscope (SEM), they show a honeycomb facto differential diagnosis between chemical and enamel prism pattern, resembling that seen in acid- mechanical etiology is consequently often difficult, etched enamel. Latent or inactive erosions which, as the pathogenesis of any individual case may well through a change in the etiologic factor, are no be multifactorial. 154 rlqiJi1i
Table 2
______Siirx~j,c!f tii~i~i~~ti~~I(itiir~tirid clris.c$ciitioti o/' erosioii used in flip literatiire. Basis Nomenclature or Classification Etiology Clinical finding Source of acid extrinsic diet. medication. Swimming pool. Class I to 111, predominantly labial industrial and occlusal intrinsic eating disorders. gastrointestinal Class I to 111, predominantly per- disorders. pregnancy. alcoholism imolysis idiopathic unknown Class I to I11 Clinical severit). Class I all possible enamel only Class II all possible
Caries References Another link of erosion is the association with car- I. LEVITCHLC. BADER JD, SHUGARSDA. HEYMANNHO. Non-carious cervical lesions. J Deizt 1994; 22: 195-.207. ies, more frequently observed since the increased 7. GR~PPOJO. Abfractions: A new classification of hard tissue usage of acid- and sugar-containing sport drinks lesions of teeth. J Estlzet Dent 1991; 3: 14-19. during exercise when, due to mouthbreathing, 3. ZIPRINI, MCCLUREFJ. Salivary citrate and dental erosion. there is less salivary clearance of acids and carbo- J Det~tR~s 1949; 28: 613-626. hydrares. In this case. erosions advancing along 4. PINUBORGJJ. Putliologj, of the dentitl hnrd tissues. Copen- hagen: Munskgaard. 1970; 312-321. with poor oral hygiene are often characterized by 5. ECCLESJD. Tooth surface loss from abrasion. attrition and the presence of chalky spots and streak-shaped erosion. Detit i~ihte1982; 9: 373-381. marks in the thin enamel surrounding the lesions. 6. DARBYET. Dental erosion and the gouty diathesis: Are The chalky spots are a result of carious decalcifi- they usually associated? Dent CU.SIW1892; 34: 629-640. 7. MILLERWD. Experiments and observations on the wasting cation and are not found with good oral hygiene. of tooth tissue, variously designed as erosion, abrasion. chemical abrasion, denudation. etc. Dent Cosiii 1907; 49: 1--23. 8. PICKERILLHP. The prewntion qfdental curies orid oral sep- Saliva .six Loiiiloii: Buillic're. Tintlcill & Cos, 1923: 140. 9. LYNCHJB. BELL J. Dental erosion in workers exposed to Erosion has been studied in animals and i?rtv. in inorganic acid fumes. Br J Irid Med 1947; 4: 8486. For obvious reasons, only clinical observations but 0. MALCOLMD. PAULE. Erosion of the teeth due to sulphuric no clinical trials have been made in humans. The acid in the battery industry. Br J hid Med 1961: 18: 63-69. effect of erosive agents in the human mouth may I. TLTOMINENML. TUOM~NENRJ, FUBUSAF, MGALULAN. depend on many factors not yet elucidated, but er- Tooth surface loss and exposure to organic and inorganic acid fumes in workplace air. Coriitnimitj~ Dent Orul osion is certainly in some way influenced by sali- Epirlwiiol 1991; 19: 217--220. vary flow rate and buffer capacity as well as by the 2. TENBRUGGEN CATE HJ. Dental erosion in industry. Br J pellicle formed by salivary mucins. People with low hid Mrrl 1968; 25: 249-266. unstimulated salivary flow rates showed a much 3. FILLI~RJS, LAZARCHIKDA. Tooth erosion: An unusual case. Gerierul Drnsitrj~1994; 42: 568-569. higher risk for erosion (71), and patients suffering 4. CENTERWALLBS, ARMSTRONGCW, FUNRHOUSERLS. EL- from idiopathic erosion had lower salivary flow ZAY RP. Erosion of dental enamel among competitive rates than the controls (59). Erosion seems to be swimmers at a gas-chlorinated swimming pool. .hi J aggravated by insufficient salivary flow and/or buf- El1id<~rliiol1986: 123: 641-647. 15. JAMESPMC, PARFITTGJ. Local effects of certain medica- fer capacity. More research is. however, needed to ments on the teeth. Br Med J 1953; 2: 1252~1253. elucidate the interactions between saliva and ero- 16. ZANDER HA. Decalcification of teeth in cases of achlorhy- sion. dria. .hi J Ortliod 01.dSurg 1946; 32: 184-186. Derital erosion. Dejnition, clusslJication 155
17. SULLIVANRE, KRAMERWS. Iatrogenic erosion of teeth. J 39. CLARKDC. Oral complications of anorexia nervosa and/ Dent Child 1983; 50: 192-196. or bulimia: With a review of the literature. J Oral hfed 18. CHRISTENSENJR. A soft tissue lesion related to salicylate 1985; 40: 134-138. treatment of juvenile rheumatoid arthritis: Clinical report. 40. KNEWITZJL. DRISKOCL. Anorexia nervosa and bulimia: Pedrritr Dent 1984; 6: 159-161. A review. Compend Contin Edur Dent 1988; 9: 244-247. 19. HANNIGM. ALBERSH-K. Die erosive Wirkung von Ace- 41. ROBBND, SMITHBGN, GEIDRYS-LEEPERE. The distribu- tylsalicylsaure an Zahnschmelz und Dentin in vitro. Dtscli tion of erosions in the dentitions of patients with eating Zulmutzfl Z 1993; 48: 298-302. disorders. Er Dent J 1995; 178: 171-175. 20. SCHWEIZEK-HIRT CM, SCHAITA. SCHMIDR, IMFELDT, 42. SCHEUTZELP, MEERMANNR. Aiioresie und Bulimie (ius LUTZ E MUHLEMANNHR. Erosion und Abrasion des zalznarztlicher Sicht. Miinchen: Urban & Schwarzenberg, Schmelzes. Eine experinientelle Studie. Srlzwei: Monatsschr 1994. Znlinhrilk 1978: 88: 497-529. 43. SMITHBGN. ROBBND. Dental erosion in patients with 21. JAKVINENVK, RYTOMAA11, HEINONENOI? Risk hctors in chronic alcoholism. J Dent 1989; 17: 219-221. dental erosion. J Dent Res 1991; 70: 942-947. 44. LINKONJJ, ROPERRE, WEIDLINRA. Perimolysis: report of 22. ECCLESJD, JENKINSWG. Dental erosion and diet. J Dent case. J Soutlz Cal!fDent Assoc 1968; 36: 65-68. 1974; 2: 153-159. 45. HOLSTJJ. LANGEF. Perimolysis: a contribution towards the 23. DAVISWB, WINTERPJ. Dietary erosion of adult dentine genesis of tooth wasting from non-mechanical causes. Acts and enamel. Br Deli/ J 1977; 143: 116-1 19. Odontol Scand 1939; 1: 3648. 24. ALLAN DN. Enamel erosion with lemon juice. Br Dent J 46. BARGENJA. AUSTINLT. Decalcification of teeth as a result 1967: 122: 300-302. of obstipation with long continued vomiting: report of a 25. MILLERCD. Enamel erosive properties of fruits and fruit case. J Am Dent Assoc 1937; 24: 1271-1273. juices. J Nutr 1950: 41: 63. 47. HOWDENGF. Erosion as the presenting symptom in hiatus 26. IMFELDT. Identification of low caries risk dietary compo- hernia. Er Dent J 1971; 131: 455456. nenis. Basel: Karger, 1983; 165-174. 48. ALLANDN. Dental erosion from vomiting: a case report. 27. ASHERC. READ MJF. Early enamel erosion in children as- Br Dent J 1969; 126: 31 1-312. sociated with the excessive consumption of citric acid. Er 49. GUDMUNDSSONK, KRISTLEIFSSONG, THEODORSA. HOL- Dent J 1987; 162: 384-387. BROOK WP. Tooth erosion, gastroesophageal reflux. and sal-
28. LEviNE RS. Fruit juice erosion - an increasing danger ? J ivary buffer capacity. Oral Surg Orrrl Med Oral Parlzol Oral Doit 1973; 2: 85-88. Radio1 Endod 1995: 79: 185-189. 29. LUSSIA, JAGGIT. SCHAREKS. The influence of different 50. ECCLESJD. Dental erosion of nonindustrial origin. A clin- factors on in vitro enamel erosion. Caries Res 1993; 27: ical survey and classification. J Prostlie/ Dent 1979: 42: 387-393. 649-65 3. 30. GIUNTAJL. Dental erosion resulting from vitamin C tab- 51. Lussr A, SCHAFFNERM, HOTZ P, SUTERI? Erosion der lets. JAnz Dent Assoc 1983; 107: 253-256. Zahnhartsubstanz. Schweiz Monatsschr Zahnnzed 1992; 31. BIRKHEDD. Sugar content, acidity and effect on plaque pH 102: 321-327. of fruit juices, fruit drinks, carbonated beverages and sport 52. MANNERBERGF. Appearance of tooth surfaces as observed drinks. Caries Res 1984; 18: 120-127. in shadowed replicas, in various age groups, in long term 32. MEURMANJH, MURTOMAAH. Effect of effervescent vita- studies, after toothbrushing, in cases of erosion and after min C preparations on bovine teeth and on some clinical exposure to citrus fruit juice. Odorit Rciy 1960; I1 (Suppl and salivary parameters in man. Scand J Dent Res 1986; 6): 1-116. 94: 491499. 53. MANNERBERGE Changes in the enamel surface in cases of 33. PASSONJC. JONESGK. Atypical dental erosion: A case re- erosion. A replica study. Arch Oral Biol 1961: 4: 59-62. port. Gcrorfontics 1986; 2: 77-79. 54. HOUSERC, GRISIUSR. BLIZIOTESMM, LICHTJH. Perimo- 34. SORVARIR, KIVIRANTAI, LUOMAH. Erosive effect of a lysis: unveiling the surreptitious vomiter. Oral Surg 198 1: sport drink mixture with and without addition of fluoride 51: 152-155. and magnesium on the molar teeth of rats. Scand J Dent 55. DAVISWB, WINTERPJ. The effect of abrasion on enamel Rrs 1988; 96: 226231. and dentine after exposure to dietary acid. Er Dent J 1980; 35. SORVARIR. Effects of various sport drink modifications on 148: 253-256. dental caries and erosion in rats with controlled eating and 56. SMITHBGN. Dental erosion. attrition and abrasion. Prclr- drinking pattern. Proc Finn Dent Soc 1989; 85: 13-20. titioner 1975; 214: 347-355. 36. RYT~MAAI, MEURMAN JH, KOSKINENJ, LAAKSO T, GHAR- 57. JOHNSONGK, SIVERSJE. Attrition, abrasion and erosion: AZI L. TURUNENR. In vitro erosion of bovine enamel Diagnosis and therapy. Clin Prev Dent 1987; 9: 12-16. caused by acidic drinks and other foodstuffs. Scarid J Dent 58. LINKOSALOE, MARKKANENH. Dental erosions in relation Res 1988; 96: 324333. to lactovegetarian diet. Scand J Dent Res 1985; 93: 436- 37. HELLSTROMI. Oral complications in anorexia nervosa. 441. Scand J Dent Res 1977; 85: 71-86. 59. WOLTGENSJHM, VINGERLINCP, DE BLIECK-HOGERVORST 38. HURSTPS, LACEYLH, CRISPAH. Teeth, vomiting and diet: JMA, BERVOETSDJ. Enamel erosion and saliva. Clin Prei, A study of the dental characteristics of seventeen anorexia Dent 1985; 7: 8-10, nervosa patients. Postgrad Med J 1977; 53: 298-305.