Anders /ohansson, DDS, Or Odonl' Department of Restorative Dental Sciences College of Dentistry King Saud University Riyadh, Saudi Arabia Ridwaan Omar, BSc, BDS, LDSRCS, MSc, FRACDS" Department of Dentistry Identification and Armed Forces Hospital Management of Tooth Wear Riyadh, Saudi Arabia The etiology and treatment of occlusal tooth wear remain controversial. Longer tooth retention hy the aging population increases the likelihood that clinicians will be treating patients with worn dentitions, A careful approach to interventional clinical procedures is advocated but should not curtail definitive management of patients having identifiable and potent causative agents that produce a rapid deterioration of the dentition. This article descrihes the epidemiology and etiology of occlusal wear and presents a conservative approach to its management, int I Prosthodont 1994,7:506-516. t is probable that the increasing incidence of nat- minimal interocclusal space are thus obvious, as I ural tooth retention into older age' will result in a are the irreversibility and radical nature of com- wider prevalence of severely worn dentition than monly practiced reconstructive techniques. previously has been seen. The resultant challenges The parameters for determining what constitutes in the clinical management of such patients have severe wear and when treatment should be carried aroused considerable professional interest con- out remain unclear. Controversies also center on cerning tooth wear. the relative importance of possible causative While there are numerous etiologic factors, agents and the indicated therapy, if any, for treat- effects, and/or other more abstract phenomena ing the worn dentition. associated with tooth wear, their interrelationships remain difficult to define.-' Some of the complexi- Epidemiology ties and sequelae of these factors are illustrated in Fig 1. There is a need for clinical techniques that While there seems to be no shortage of pub- assess whether tooth wear for a given individual is lished reports of anthropologie studies of tooth in the range of normal or pathologic, and that reli- wear in earlier populations,'-'" investigations ably measure the severity and rate of progression describing the contemporary epidemiologic status of such wear/ of tooth wear are seldom found. It may be that the When extensive wear occurs, it is frequently prevalence of extensive wear in contemporary localized to the anterior teeth, and often in only populations has been considered to be so low that one arch. Severe wear rarely affects all teeth to the epidemiologic investigations would be meaning- same degree^ (Figs 2a to 2c). Thus, the majority of less, at least for western populations. interventional procedures for worn dentitions However, certain nonwestern populations, for involve the restoration of only the anterior teeth. example Australian aborigines, Eskimos, and The clinical problems of short clinical crowns and Saudis, have been shown to exhibit significant tooth wear." '- Recent generations of these popula- tion groups, while showing predictably reduced 'Assistant Professor and Const: i tant. tooth wear with the transition from rural to urban "Postgraduate Clinicai Tutor and Consultant. lifestyles, nevertheless still experience a rate and a Reprint requests: Or Anders Johansson, Department of degree of wear that exceeds that of western popu- Restorative Dental Sciences. College of Dentistry, King Saud lations. It has been suggested, consequently, that University, P.O. Box 60169, Riyadh I ¡545, Saudi Arabia. the changing lifestyle accompanying urbanization The [nlernational lournal of Proslhodonlic 506 Idenliíi calió n and Mana eniuf Tooth Wear Fig 1 Sixty-five-year-old Swedish man witti an extremely Fig 2a Twenty-one-year-old heavily built Swedish sports- wom dentition. There is pronounced mandibular anterior wear man with extreme loss ot maxillary clinical crown height. He opposing the maxillary rnetal ceramic crown. The overall had previously ccnsumed cola daily tor 5 years, and had the reduced dimensions of the maxillary teeth indicate the com- habit of keeping the beverage in his mouth to better enjoy the bined effects of incisai, occlusal, and proximal wear. While taste betöre swallowing. In addition to the extremely short several possible etiologic factors were present, the increased clinical crowns, there is also considerable reduction cf functional loading on the anterior teeth following lost posterior meslodistal width. support is probably ot greatest importance. or "cultural development" reduces the potential for tooth wear,'^ and that the advanced wear that does occur in such populations is usually regarded as a variation from the norm.- Comparing the findings in various reports on tooth vyear frequently presents the problem of dif- fering assessment methods. Only the use of stan- dardized and unified evaluation techniques would permit absolute interpopulation comparisons. For example, many investigators use "exposed dentin" as the one sign of obvious wear, and this is proba- Fig Zb Left buccal view of the same patient in the interous- pal position. The large interincisal space between maxillary bly the most consistent feature within the various and mandibular central incisors is indicative of loss of tooth grading criteria used. An epidemiologic study'-* substance by erosion reported that only 2% of 585 randomly selected Swedish adults aged 20 to 80 years had one or more teeth with extensive wear, while in those aged 20 to 29 years, 14% of examined teeth had marked enamel wear or dentinal exposure. In 717 randomly selected Swedes aged 20 to 80 years, 41% of individuals showed dentinal exposure, but in those aged 20 to 29 years the frequency was 20%." Another study reported a prevalence of only 6% of teeth with dentinal exposure in orthodonti- cally untreated subjects, although it should be noted that the age of all individuals in this sample was 19 years,'^ in contrast to these findings in Fig 2c Maxillary view of the same patient. The pulp cham- western population samples, a similarly aged bers are visible througfi the thin remaining dentin on the cen- young adult (aged 19 to 25 years) Saudi population tra! incisors and the left lateral incisor. This is a sign of a rapid wear progression. With siower progression, puips would possessed a 45% frequency of dentinal exposure of rarely become involved since secondary dentin would have teeth examined (Table 1).'- Such an experience of had time to torm. wear in Saudis can probably be ascribed, in part, to the sandy and harsh desert environment in which they live.'' Ambient climatic and environ- mental factors may, therefore, play a role in the 7, Number 6, 1994 507 T lie Internation al of ProBthodontii nd ManagementolTooLhi We lo han Mon/On Table 1 Prevalence of Tooth Wear of Young Adults in Some Recently Published Studies No. of Age Population Prevalence of Authors subjects (v! Country sample Wear cnteria vKorn teeth Hugosonetai(1988!" 100 20-29 Sweden Random Wear of enamel or into dentin in 14% single spots or wear ot dentin < 'h of crown height Dahletal (t989!'= 47 19 Norway Orthodontically Small areas of exposed dentin or 6% untreated OÖVIOUS tooth length reduction Fareed et al (1990)" 206 19-25 Saudi Arabia Dental students Wear into dentin or extensive wear 45% ment, such as canine guidance, anterior guidance, or group function.'" Similarly, diet (ie, coarse and acidic substances], diseases (eg, gastric conditions, anorexia nervosa), salivary composition (ie, buffer capacity, secretion rate, and variations in calcium ion concentration!, and occupational environment (eg, airborne abrasives, acid) have been found to be associated with tooth wear.'''"'' Also, reduced occlusal tactile sensitivity, high occlusal force, and increased endurance time, all of which reflect muscle and functional proprioception, have been shown to be correlated to extensive wear.^* Extensive wear is also associated with age and gen- Fig 3 Fifty-one-year-old Saudi man exhibiting a uniformly der. It is more commonly seen in older individuals severely worn dentition. Almost all the teeth show extensive and is seldom seen in females.''-' wear into dentin and several into secondary dentin Such a ciinical picture is a common tinding among Saudis and can It is generally found that in botb arches anterior probably be ascribed to the fine ambient sand particles cf the teeth (and anterior tooth wear indices) exhibit sig- hot and dry desert terrain. nificantly greater wear than posterior teeth.-' The precise cause of the higher frequency of worn anterior teeth remains unclear. It is generally held wear experience of certain contemporary popula- that in earlier populations, the excessive wear of tions (Fig 3). However, in a young adult (aged 17 molars resulted mainly from a coarser diet and to 24 years! Indian population, wear was found to from the more vigorous maslicatory activity be less than in western equivalents. The minimal required. Wear of anterior teetb also results from wear experienced by this sample was speculated to nondietary functions such as holding and manipu- have been a result of the method of food prepara- lating.™ It can be speculated that in contemporary tion and ingestion.'° humans, wear-inducing factors are likely to affect the anterior teeth more than the posterior. For Etiology example, intrinsic acid and bruxism (which are common in modern humans! primarily affect the The terms attrition, erosion, and abrasion are not anterior teeth, while the absence of a coarse