The prevalence, etiology and management of tooth wear in the United Kingdom

The prevalence, etiology and management of tooth wear in the United Kingdom Bernard G. N. Smith, BDS, PhD, MS, MRD, a David W. Bartlett, BDS, PhD, MRD, ~ and Nigel D. Robb, BDS, PhD c

UMDS, Guy's Hospital, London, United Kingdom Statement o f p r o b l e m . Recent epidemiologic evidence suggests that tooth wear is now a significant problem in both children and adults. There is growing evidence that a major cause of the severe wear in patients is regurgitation erosion due to a variety of factors including gastroesophageal reflux disease. P u r p o s e . The purpose of this article is to discuss the prevalence of tooth wear in the United Kingdom. Emphasis in management should be on accurate diagnosis, and in some patients, long-term monitoring before embarking on any irreversible, intervenfive treatment. Even when treatment is necessary, a period of monitoring is helpful to assess the rate of progress of the wear, the effectiveness of preventive measures, and therefore the extent of the treatment necessary.(J Prosthet Dent 1997;78:367-72.)

I t is not always possible to differentiate between erosion, attrition, and abrasion, as these conditions frequently occur in combination. It is therefore necessary to have a term for the condition in which teeth become worn and tooth wear is a convenient, simple term readily understood by patients. This is important because the management o f tooth wear relies on the patient understanding the nature o f the condition, so that the patient can provide sufficient information (sometimes sensitive or embarrassing) to the clinician to allow for a differential diagnosis and to prevent further progression. An alternative term, tooth surface loss (TSL), has been proposed. 1 However, this term has two significant disadvantages. First, it understates the severity o f the condition by implying that only the surface o f the tooth is lost, whereas in some situations, the wear can be very extensive. The second disadvantage o f the term is its subtlety that escapes most patients and some dentists. The term was originally proposed to differentiate tooth surface loss from tooth subsurface loss, the latter being a way o f describing early enamel caries. This distinction is i m p o r t a n t because early e n a m e l caries can be remineralized, whereas once the surface o f the enamel is lost, there is no matrix in which remineralization can take place. This distinction is important to scientists and clinicians but is less useful in communicating with patients. DEFINITION

OF TERMS

The terms erosion, attrition, and abrasion should only be applied clinically when there is strong evidence that the differential diagnosis is clearly one o f the three conPresented at the Academy of Prosthodontics, Newport Beach, Calif., May 1996. ~Professor, Department of Conservative Dentistry. bLecturer, Department of Conservative Dentistry. CLecturer, Department of Restorative Dentistry, The Dental School, Newcastle upon Tyne, U.K. OCTOBER 1997

ditions. When there is inadequate evidence or when a combination o f causes is present, then the term tooth wear is preferred. Erosion is the result o f chemical damage (acids) excluding chemicals produced by bacteria. Attrition is defined as the physical wear o f one tooth against another, which means that only tooth surfaces that make contact with each other can be described as having attrition. Abrasion is the physical wear o f the tooth surface by something other than another tooth. PREVALENCE OF TOOTH UNITED KINGDOM

WEAR IN THE

There have been two major surveys in recent years, one o f adult patients in the South East o f England 2 and the other a national survey o f children conducted by a government agency. 3 The adult survey used the T o o t h Wear Index (TWI). 4 This index was designed to record levels o f tooth wear regardless o f the cause. It has been used in a number o f studies, 5-7 the largest being 1007 patients in the South East o f England. 2 Briefly, each visible tooth surface (facial, lingual, and occlusal/incisal) is recorded together with a separate score for the facial cervical region, which sometimes suffers a different pattern o f wear. Scores from 0 to 4 are given, according to the severity o f wear (TWI manual2.~). A problem in recording tooth wear is some wear is natural and progresses throughout life in contrast to caries and periodontal disease, which should not occur at all. The TWI therefore incorporates threshold values for each tooth surface for each decade o f age, and a computer program calculates unacceptable levels o f wear (above these thresholds). For example, Figure 1, A shows a mandibular molar with cupped out wear defects through to dentin in a 17-yearold patient. This amount o f wear is unacceptable or pathologic for this age. Figure l , B shows a much more extensive pattern o f wear, with dentin exposed across most o f the molar occlusal surface in a 75-year-old patient. Assuming that this wear had been progressive THE JOURNAL OF PROSTHETIC DENTISTRY

367

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SMITH, BARTLETT, AND ROBB

0

5

10

15

20

M e a n T o o t h W e a r Score

Fig. 2. Mean tooth wear scores for four groups of patients particularly vulnerable to dental erosion compared with equal numbers of age- and sex-matched controls. Patients in first three groups were categorized by psychiatrists treating them. Abstaining anorexics and bulimic patients had classic symptoms of their conditions. Vomiting anorexics had episodes of vomiting in addition. Chronic alcoholics were attending center for treatment of alcoholism. 4.62%. The explanation for the decrease from the first age group to the middle age groups is that the threshold levels, although increasing with age, assume a steady increase in wear throughout life. This appears not to be the case and there is evidence that some young people under the age o f 26 years have accelerated rates o f wear and those over the age of 55 years also have a greater proportion o f their tooth surfaces unacceptably worn. The absolute figures are troubling. In particular, the older age groups who retain their natural teeth longer are likely to need a substantial amount o f treatment if more than 8% o f their t o o t h surfaces are worn to an unacceptable degree. However, not all o f these worn surfaces may need treatment. W h i c h patients are m o r e at risk?

Fig. 1. A, Cupped out wear defects on occlusal surface of 17year-old patient. B, Dentin exposed by wear across almost all occlusal surface in 75-year-old patient. t h r o u g h o u t life, the chances are this t o o t h will remain symptomless and functional. Therefore this a m o u n t o f wear, at this age, could be regarded as acceptable. PREVALENCE

IN ADULTS

The results of the survey of 1007 patients 2 showed that, for the 15- to 26-year-age group, 5.73% o f tooth surfaces were worn to an unacceptable degree. In the 56- to 65year-age group, the wear was 8.19% and wear in the over 65-year-age group was 8.84%. The figures for the three intermediate decades were lower, between 3.37% and 368

It is n o w firmly established T M that anorexia nervosa and bulimia nervosa are strongly related to dental erosion, particularly the palatal surfaces o f the maxillary incisor teeth. Erosion later spreads to other teeth beginning with the occlusal and facial surfaces o f the mandibular molar and premolar teeth. Chronic alcoholism produces a similar pattern o f erosion, although usually more generalized, n-14 Figure 2 illustrates the differences in mean T o o t h Wear Score between four study groups and age- and sex-matched controls from the survey previously described. 4 D o e s loss o f p o s t e r i o r s u p p o r t increase t h e w e a r o f a n t e r i o r teeth? It has often been assumed that there must bc a relationship between loss o f posterior support and increased wear o f the occluding surfaces o f anterior teeth. This assumption, although appearing to be c o m m o n sense, VOLUME 78 NUMBER 4

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is not logical when the physiology of the masticatory system is considered. The mechanical assumption is that there is a certain amount of chewing to bc done and, if the posterior occlusal table is reduced, then this function will be transferred to the anterior teeth. In fact, the amount of force applied to any tooth is limited by its proprioceptive feedback mechanism triggered by the mechanoreceptors in the periodontal membrane. The physiologic view is therefore that each tooth will sustain a certain amount of force regardless how many other teeth are involved in mastication. In the study of 1007 patients, correlation coefficients were calculated for the TWI score For the relevant anterior tooth surfaces and the number of missing posterior teeth (Fig. 3). It can be seen that, although all positive, nearly all the correlation coefficients were less than 0.3, with the exception of the maxillary incisal surface, for the over 65-year-age group. This was 0.51 and was just statistically significant. However, if the wear on the maxillary incisal edges had been due entirely to attrition, the wear on the mandibular incisal edges would have been similar. The implication is that a secondary factor, presumably erosion, influenced the maxillary incisal edges in at least some of the patients. This evidence, although by no means conclusive, suggests that posterior tooth loss does not significantly affect anterior tooth wear. PREVALENCE CHILDREN

OF DENTAL EROSION

IN

Corl Coe

0.6 0.5 0.4 0.3

0.2 0.1

Fig. 3. Correlation between tooth wear score and number of missing posterior teeth for four age groups. Number of missing teeth potentially ranged from nil (all molar and premolar teeth present) to 20 (N = 776).

% o f Children with Erosion

35

o

15

°J 7

A national survey of over 2,000 children conducted in the United Kingdom in 1993 examined all aspects of oral health, s One measurement was dental erosion of the maxillary anterior teeth. The results for permanent incisor teeth in children betwecn 7 and 15 years of age are illustrated in Figure 4 and are distressingly high. Some evidence of palatal enamel erosion was seen in more than a quarter of the subjects over 11 years of age and was sufficiently severe in 13- to 15-year-old subjects to have penetrated to dentin in between 2% and 3% ofthc subjects. The Survey Report s suggests that this may be due to an increase in the consumption of soft drinks, which contain acid, but offers no evidence to support this assumption. ETIOLOGY

OF EROSION

In addition to this survey of children, there is growing evidence that erosion rather than attrition or abrasion is the major cause of tooth wear. ~6-19Certainly, the extent of the wear, particularly in young age groups, is much greater when the causc is erosion compared with other causes. Dental erosion is now recognized as being caused by one or more of the following factors, and perhaps some other factors as yet unknown: regurgitation occurring in the eating disorders, gastroesophageal reflux disease (GERD), morning sickness, chronic alcoholism, hiatus hernia, and voluntary rumination. 2° OCTOBER 1997

jJ

30

8

9

10

Fig. 4. The proportion of children with erosion affecting the permanent incisor teeth.

The Following dietary items, taken to excess, are thought to produce dental erosion: Fruit juice and carbonated drinks, citrus Fruit, picldes, spicy Food, and vinegar. Some industrial processes producing acid fumes and droplets cause dental erosion, although this is now less common with improved industrial practices. Also, some medications are acid. A common example is chewable vitamin C tablets that have a p H of about 2. The coFactors that affect the extent of erosion include the flow rate and buffering capacity of saliva and the effect on saliva of some common drugs such as the diuretics and many of the antidepressants. The e n a m e l / dentin susceptibility to erosion may be influenced by the fluoride content. Recent studies 212s have shown that regurgitation erosion in patients with GERD is closely related to dental erosion, particularly palatal erosion of the maxillary incisor teeth. By using the standard internationally accepted tests for GERD, including 24-hour monitoring of esophageal pH together with oral pH, this study related these measurements to dental erosion. Figure 5 illustrates the 369

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GERD + Symptoms +

GERD + Symptoms-

GERDSymptoms +

~

6

GERD Symptoms 5

10

15

20

N u m b e r of Patients

Fig. 5. Number of patients with and without gastroesophageal reflux disease and with and without symptoms. All 40 patients had well-established palatal erosion exposing large areas of dentin.

Fig. 6. Casts of occlusal surface of maxillary occlusal splint taken 3 months apart. Cast on left shows wear facet developing, due to attrition. Cast on right shows further development of wear facets.

toration difficult if allowed to continue. Currently, it is believed that active treatment is provided too early in many patients. 26 PREVENTION

number o f patients with and without GERD and with and without symptoms in 40 patients with well-established palatal erosion, exposing large areas o f dentin in all patients. The relationship between symptoms and GERD in 16 of the patients is to be expected, but the finding that 9 of this sample of 40 patients (36%) had no symptoms and yet were diagnosed as having GERD is surprising. These are patients lmown by gastroenterologists as "silent refluxers." GERD is a cyclical condition and not all patients who suffer from it are diagnosed during a single 24-hour p H monitoring period. It is therefore possible that some o f the nine other patients who were not diagnosed with GERD and also who did not have symptoms may have produced evidence o f GERD if the measurements had been taken at another time. MANAGEMENT

AND TREATMENT

Tooth wear is a condition that affects the patients' dentitions for the remainder o f their lives. A lifelong approach to management should therefore be taken rather than short-term expedient treatment measures. The emphasis should be on persistent efforts to identify the cause o f the wear and appropriate prevention instituted with the same enthusiasm that dietary control and oral hygiene are emphasized in the prevention o f caries and in the management o f progressive periodontal disease, respectively. Long-term monitoring is necessary to assess the effectiveness o f preventive measures and any further progression o f the wear before deciding whether interventive treatment is necessary. Restorative treatment is only necessary when one o f the following criteria is met. Active treatment is premature unless one of these indications is present: The patient is presently concerned about his or her appearance; tooth sensitivity or pain that cannot be controlled conservatively; or progressive, uncontrollable wear that is altering the occlusal vertical dimension or will make res370

It is not possible to describe herein the details o f the methods o f prevention of the eating disorders, chronic alcoholism, or GERD that are mainly medical in nature but to which the dentist can make a significant contribution. Ira dietary cause is clearly identified, the dentist has a major role in preventing erosion. Preventing attrition caused by nocturnal bruxism is difficult, but hard acrylic resin occlusal splints can be effective. Figure 6 shows casts o f the occlusal surface of a maxillary occlusal splint taken 3 months apart. Wear facets can be seen developing in the occlusal surface in the cast on the left and these have progressed significantly in the cast on the right• This technique is valuable in establishing that nocturnal bruxism is the cause o f attrition. Continuing to wear an acrylic resin occlusal splint at night absorbs the wear on the splint rather than further damaging the teeth. In severe, long-term situations, a cobalt chromium skeleton base can be used with occlusal surfaces in acrylic resin, which can be replaced as necessary. MONITORING Monitoring by periodic clinical examination is subjective, and objective records should be kept. These may be photographic records or study casts. Figure 7, A and B, shows the maxillary incisor teeth o f a 15-year-old boy who has palatal erosion that has exposed wide areas o f dentin. This has become stained, showing that the erosion is no longer active• Active erosion leaves a clean, unstained surface. The teeth were not sensitive, the labial appearance was not affected (Fig. 7, B) and the incisal edges have not been shortened• There was therefore no need to treat this condition, but there was a long-term need for continual monitoring in the event that the cause o f the erosion (which had not been reliably identified) returned• Figures 8 and 9 show sets of study casts taken several VOLUME 78 NUMBER 4

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Fig. 7. A, Stain on eroded palatal surfaces of incisor teeth of 15-year-old boy. B, Labial surfaces showing no stain and no loss of incisal length.

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Fig. 9. These casts taken 9 years apart show some progression in wear of mandibular incisor teeth, but little further wear of posterior teeth. It would have been difficult to restore teeth in 1981 and there was no indication to do so because patient had no significant complaints of appearance or sensitivity. Leaving teeth unrestored for these 9 years has done no significant harm and has avoided possible complications of difficult restorations. Incidentally result of further wear has produced more uniform occlusal plane.

Fig. 8. Cast on left was taken when patient was in his early sixties. He had just had mandibular right first molar extracted. Cast on right was taken 10 years later and there has been insignificant progression of wear, which had been largely due to erosion. Until time that first cast was taken, he was eating spicy, Asian diet, producing regurgitation. Later when his wife died, he dramatically changed to bland diet and regurgitation ceased.

Fig. 10. Casts on left show eroded maxillary incisor teeth and overerupted mandibular incisor teeth, Casts on right show result of orthodontic treatment to depress mandibular incisor teeth, thereby creating space for crown preparations on maxillary incisors without reducing eroded palatal surfaces any more. This approach produced more esthetic appearance and is less destructive than crown lengthening and conventional crown preparations.

years apart. Figure 8 shows that wear had not continued and Figure 9 shows casts where it had, although treatment was still not indicated.

maining to produce retentive preparations, but in others, the wear has progressed to the point where further preparation o f the worn surfaces would be unwise. In these situations, the occlusion is usually disrupted and some localized orthodontic treatment to intrude the teeth, which have supraerupted as a result o f wear, is preferable to crown lengthening. This can be achieved by conventional orthodontic treatment (Fig. 10) or by the use o f a fixed Dahl appliance (Fig. l l , A, B, and C). 27,28

TREATMENT When treatment is indicated for one of the above reasons, the minimum treatment necessary to solve the problem should be used. This will range from simple desensitizing procedures through conventional restorations to multiple crowns. With regurgitation erosion that has progressed to the point where the incisal edges are significantly reduced or the labial surfaces are affected, it is often necessary to crown at least the six maxillary anterior teeth. In some situations, there is sufficient dentin reOCTOBER 1997

SUMMARY The prevalence o f unacceptable levels o f tooth wear in the United Kingdom is high, particularly in older age groups where substantial treatment may be necessary. 371

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REFERENCES

Fig. 11. A, Maxillary teeth have been eroded both palatally and labially by regurgitation. B, Fixed Dahl appliance bonded to maxillary anterior teeth acting as simple orthodontic appliance to depress mandibular incisors. C, After wearing DaN appliance for 3 months, clearance between maxillary and mandibular incisor teeth is achieved so crown preparations can be made with minimum further palatal tooth reduction.

There is also a high amount o f erosion in children, at least in the United Kingdom. Patients specifically at risk include those with eating disorders (anorexia or bulimia nervosa), chronic alcoholics, and patients with diagnosed and undiagnosed GERD. Posterior tooth loss is probably not significantly related to anterior tooth wear. Long-term management of tooth wear should start with a sound differential diagnosis, strenuous efforts at prevention, long-term monitoring, and proceed to active treatment only when indicated. When treatment is indicated, it should be limited to solving specific problems, although this may well indicate extensive reconstruction in s o m e s i t u a t i o n s . Figures 6, 7a, 8, 9, and 10 were borrowed with permission from Smith BGN, Some Facets of Tooth Wear (Ann R Austr Coil Dent Surg 1991 ;11:37-51 ). 372

I. Eccles JD. Tooth surface loss from abrasion, attrition and erosion. Dent Update 1982;9:373-81.. 2. Smith BG, Robb ND. The prevalence of tooth wear in 1007 dental patients. J Oral Rehabil 1996;23:232-9. 3. O'Brien. Children's dental health in the United Kingdom, 1993. HMSO 1994: 74-6. 4. Smith BG, Knight JK. An index for measuring the wear of teeth. Br Dent J 1984;I 56:435-8. 5. Donachie MA, Walls WAG. Tooth wear in an aging population in the North East of England. J Dent Res 1991;70:684 (Abstract 125). 6. Milosevic A, S]ade P. The orodental status of anorexics and bulimics. Br Dent J 1984;I 67:66-70. 7. Poynter E, Wright PS. Tooth wear and some factors influencing its severity. Rest Dent 1990;6:8-I I. 8. Hellstrom I. Oral complications in anorexia nervosa. Scand J Dent Rest 1977;85:71-86. 9. Hurst PS, Lacey JH, Crisp AH. Teeth, vomiting and diet: a study of the dental characteristics of 17 anorexia nervosa patients. Postgrad Med J 1977;53:298-305. 10. Milosevic A, Slade P. Dental characteristics of anorexia and bulimia nervosa. J Dent Res 1989;68:980 (Abstract 907). 1I. Robb ND, Smith BGN. Anorexia and bulimia nervosa (the eating disorders): conditions of interest to the dental practitioner. J Dent 1996;24:7-I 6. 12. King WH, Tucker KM. Dental problems of alcoholic and non-alcoholic psychiatric patients. Q J Stud Alcohol 1973;34:1208-I I. 13. Simmons MS, Thompson DC. Dental erosion secondary to ethanol-induced emesis. Oral Surg Oral Med Oral Patho11987;64:731-3. 14. Smith BGN, Robb ND. Dental erosion in patients with chronic alcoholism. J Dent 1989;I 7:219-21. 15. Robb ND, Smith BG. Prevalence of pathological tooth wear in patients with chronic alcoholism. Br Dent J 1990;I 69:367-9. 16. White DK, Hayes RC, Benjamin RN. Loss of tooth structure associated with chronic regurgitation and vomiting. J Am Dent Assoc 1978;97:833-5. 17. Jarvinen V, Meurman JH, Hyvarinen H, Rytomaa I, Murtomaa H. Dental erosion and upper gastro intestinal disorders. Oral Surg Oral Med Oral Pathol 1988;65:298-303. 18. Aine L, Baer N, Maki M. Dental erosions caused by gastroesophagea[ reflux disease in children. ASCD J Dent Child 1993;60:210-4. 19. Smith BGN, Knight JK. A comparison of patterns of tooth wear with aetiological factors. Br Dent J 1984;I 57:16-9. 20. Gilmour AG, Beckett HA. The voluntary reflux phenomenon. Br Dent J 1993;I 75:368-72. 21. Bartlett DW, Evans DF, Smith BG. The relationship between gastro-oesophagea[ reflux disease and dental erosion [review]. J Oral Rehabil 1996;23:289-97. 22. Bartlett DW, Evans DF, Smith BGN. Oral regurgitation after reflux provoking meals; a possible cause of dental erosion? J Oral Rehabil 1997;24:1028. 23. Bartlett DW, Evans DF, Anggiansah A, Smith BG. A study of the association between gastro-oesophageal reflux and palatal dental erosion. Br Dent J 1996;181:125-31. 24. Bartlett DW, Smith BGN. The dental relevance of gastric reflux part I. Dent Update 1996;23:205-8. 25. Bartlett DW, Smith BGN. The dental relevance of gastric reflux part II. Dent Update 1996;23:250-3. 26. Smith BG. A personal historical view of the management of tooth wear. Br Dent J 1996;I 80:204-5. 27. Ricketts DN, Smith BG. Minor axial tooth movement in preparation for fixed prostheses. Eur J Prosthodont Rest Dent 1993;I :145-9. 28. Ricketts DN, Smith BG. Clinical techniques for producing and monitoring minor axial tooth movement. Eur J Prosthodont Rest Dent 1993;2:5-9. Reprint requests to: DR, B. G. N. SMITH GUY'S HOSPITALDENTALSCHOOL LONDONSE1 9RT UNITED KINGDOM Copyright © 1997 by The Editorial Council of The Journal of Prosthetic Dentistry. 0022-3913/97/$5.00 + O. 10/1/82644

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