Tooth wear: screening, diagnosis and management in general dental practice

Initial assessment – screening

During routine dental examinations, patient's complaints (Table 1) and histories (Figure 2) may already highlight the condition of TW.

Indices have been used in the past to assess the severity of tooth wear. Table 2^5,-9 summarizes the four most popular ones used in previous research.¹⁰ Clinically, it is impractical for busy general dental practitioners (GDPs) to carry out full TW charting for every patient as a part of their examination. Therefore, the simple and quick BEWE (Table 3) is ideal for screening purposes. In addition, the associated management guideline (Table 4) also provides clear guidance according to different cumulative scores.^5,6 Although the BEWE was originally developed to examine and record the severity of erosive wearing lesions, it was validated to assess all types of TW.¹¹ Nonetheless, the BEWE management grid has inherited some inadequacies:

Using an additional age-related RAG grid (Table 5) and management pathways (Figure 3), the above inadequacies can be overcome. The age-groups in the Adult Dental Health Survey³ were used as a reference to decide the cut-off ages for each group in the RAG grid. The cumulative BEWE tiers were decided, based on hypothetical case scenarios with increasing severity (Table 6). The ‘Any BEWE’ and ‘≥50% BEWE 3’ were designed to address localized situations and missing sextants (ie partial BEWE). Once the GDP has become familiarized with the BEWE and RAG grid, the TW screening should only occupy approximately one minute of the examination appointment (Table 7).

Red and amber management pathways – Step 1

Detailed assessment

The first step of the TW-Red (predominantly pathological) and TW-Amber (mixed) management pathways is detailed assessments (Table 8). These assessments can be carried out in a separate appointment. This will allow the patient to complete a diet analysis sheet. Compared with the diet history sheet for high caries risk patients, the one in Figure 4 has also incorporated the components of intrinsic factors and brushing habit.

Table 8. Detailed assessments for TW-Amber and TW-Red.

Recommended Assessments	Dietary and intrinsic acid analysisFull-mouth TW charting (eg Figure 5) and pattern analysis
Additional Special Investigations (if necessary)	Interview to gather information about possible eating disorder, alcohol and recreational drug habitExtra-oral and mucosal examinationsExisting ceramic restorations analysisPalpation, percussion and mobility testingVitality testing (to identify endodontic complication)RadiographsArticulatory and occlusal assessmentAesthetic assessmentSalivary analysis (flow rate and buffering capacity)
Liaise with Other Health Professionals (if necessary)	Medical GP (to identify intrinsic causes and cause of xerostomia)Psychologist (to assess eating disorder, anxiety and depression)

Similar to a full probing depth charting for periodontitis, a full TW charting is necessary to disclose the disease pattern of the pathological and mixed TW. It also facilitates diagnosis and treatment planning as well as enhancing patient communication. An example of a full charting using the Tooth Wear Index (TWI) (Table 9) is illustrated in Figure 5.

Table 9. Tooth wear index (TWI) according to Smith and Knight (1984).8

Score	Surface	Criteria
0	B/L/O/IC	No loss of enamel surface characteristicsNo loss of contour
1	B/L/O/IC	Loss of enamel surface characteristicsMinimal loss of contour
2	B/L/OIC	Loss of enamel exposing dentine for less than one-third of the surfaceLoss of enamel just exposing dentineDefect less than 1 mm deep
3	B/L/OIC	Loss of enamel exposing dentine for more than one-third of the surfaceLoss of enamel and substantial loss of dentineDefect less than 1–2 mm deep
4	B/L/OIC	Complete loss of enamel, or pulp exposure, or exposure of secondary dentinePulp exposure or exposure of secondary dentineDefect more than 2 mm deep, or pulp exposure, or exposure of secondary dentine

Patients with eating disorders, alcohol abuse problems or recreational drug habits are usually more secretive when a friend or family is present. Moreover, they may not want to disclose these habits to their own dentists. Cheilosis, parotid gland enlargement and fine fair facial hair may be present in patients with eating disorders.¹³ Tooth-grinding reported by the patient's bed-partner, tender masticatory muscles in the morning or cheek and tongue indentations usually indicate sleep bruxism.¹⁴ A long-term grinding habit can contribute to attrition. On the other hand, the porcelain occlusal surface of a ceramic restoration can cause significant abrasion to the opposing tooth.¹⁵

Full aesthetic assessment may be necessary, especially when the patient is concerned with his/her appearance. Anterior TW can destroy the harmony of dental aesthetics by making the crown height to width ratio disproportionate. It can also change the amount of teeth showing, which may result in an ageing smile.¹⁶

Diagnosis

Sound diagnosis is crucial to identifying the treatment needs and formulating an appropriate management plan. One must bear in mind that the BEWE-RAG system is just a screening tool. It can neither provide a diagnosis nor evaluate the current risk. Definitive diagnosis and aetiologies can usually be reached after the detailed assessments. Table 10 has summarized some key points that should be included in a TW diagnosis.

Table 10. Key points should be included in diagnosis of tooth wear.

Nature	Localized or generalizedSeverity (mild, moderate or severe)Predominantly pathological or physiological or mixedCurrent risk level (high, medium or low)
Aetiologies	Primarily by erosion, attrition, abrasion or abfractionModified by one or more of above factors
Evident to Support the Aetiologies	Relevant historiesPatterns and morphologies of the TWFindings of the special investigations
Others	Dentine hypersensitivityEndodontic complicationOcclusal complicationAesthetic complicationChipping or fracturing of tooth substances

Sometimes, the lesion's pattern or clinical features may suggest the disease aetiologies.¹⁷ These are summarized in Table 11 and Figures 6–8. The role of erosion, attrition, abrasion and abfraction changes over time on a tooth surface. Practitioners can easily fall into a trap and conclude that the cause of a cervical lesion, such as Case 4 (Figure 9), is from toothbrushing. However, an in vitro study has shown that 80–100 years of toothbrushing with toothpaste may be required to produce 1 mm dentine loss.¹⁸ Therefore, it is unlikely that abrasion can be the sole cause of significant pathological TW. In fact, the Adult Dental Health Survey 2009³ found that the prevalence of tooth wear was actually higher in subjects who brushed less than twice a day. So, an advanced non-carious cervical lesion (NCCL) which exposed the pulp is likely to be caused by abfraction, erosion and abrasion to varying degrees at different times.

Table 11. Clinical features against aetiology chart.

Aetiologies		Clinical Features
Predominantly Erosion	General (Figure 6 – Case 1)	Affect all surfaces but less on buccal surfaces of upper first molars and lingual surfaces of anterior teeth due to buffering effect of saliva Enamel cupping of incisal or occlusal surfaces Proud restorations Worn incisal or occlusal surfaces unable to make occlusal contact at all
	Extrinsic vs Intrinsic Patterns	Buccal erosive lesions at upper incisors and canines are closely related to extrinsic acid Lingual erosive lesions at upper canines, lower incisors, upper and lower premolars are closely related to intrinsic acid17
Predominantly Attrition		Affects occlusal surfaces Shiny facets Corresponding to opposing teeth like jigsaw-type fitting on excursions (Figure 7 – Case 2)
Predominantly Abrasion	Toothbrushing	Affects cervical areas Supragingival lesions
	Porcelain	Affects occlusal surfaces of opposing teeth (Figures 8a and b – Case 3)
Predominantly Abfraction		Affects cervical areas at cemento-enamel junction with sharp edges

Logical treatment planning and timetable

Tooth wear may be a slow process¹⁹ and will therefore rarely significantly deteriorate within a couple of years. Initial treatment should aim at stabilizing and preventing periodontal disease and caries. Although the TW on the upper first molars of Case 5 (Figure 10) may be the first thing which a dentist notices, this patient's attention should be drawn towards smoking, oral hygiene and periodontitis.

In addition to prioritizing managements into different stages, it is imperative to check the outcome of the previous management before proceeding further. Some patients may take longer to achieve a satisfactory outcome than others. If so, the treatment sequence must be driven by a patient's oral health rather than by a patient's desire. Operative treatment for TW is seldom indicated in the first stage and sometimes no such treatment may be the best option. Table 12 has summarized the logical treatment cascade.

Table 12. Incorporating TW managements (in red) into the logical treatment cascade.

Stages	Procedures
1. Emergency care	Stop bleeding, relieve pain, reduce swellingUrgent extractionsDressing and temporary fillingsCancer referral
2. Disease control	OHI, scaling and remove other plaque retentive factorsDietary analysis and adviceOther advices including TW-relatedProfessional and self-applied fluoride regimenSmoking cessation adviceCaries stabilizationExtraction of non-restorable teethReferral to manage gastric reflux, alcohol abuse, eating disorder, anxiety and depression
3. Re-evaluation	Confirm satisfactory outcome of above
4. Definitive care	Root surface debridementPermanent restorationEndodontics treatmentOcclusal splint therapyInterim removable denture(s)
5. Re-evaluation	Confirm satisfactory outcome of above and no active diseaseRegular assessment of periodontal, caries and other disease risksTW monitoringPreventive advice reinforcement
6. Rehabilitation and elective treatments (if indicated)	OrthodonticsOcclusal planning – conformative or reorganizedAesthetic treatments (include whitening)Direct adhesive restorations for TW purpose including the direct DahlPre-restorative and pre-prosthetic surgeryProvisional indirect restorations and prosthesisIndirect restorations and prosthesisImplant placement and superstructure construction
7. Maintenance and recall	Regular assessment of periodontal, caries and other disease risksTW monitoringPreventive advice reinforcementMonitor restorations and repair or replace when necessary

Red and amber management pathways – Step 2: Prevention

For TW-Amber and TW-Red, the next step of the management pathways is prevention (Table 13). However, many patients may find that preventive advice can be confusing and sometimes contradicting (Figure 11). Therefore, advice should be carefully chosen according to the diagnosis, aetiologies and risk level. A diet analysis sheet (Figure 4) is a good tool to provide clear individualized preventive advice. Emphasis should be made on frequent intrinsic acid attacks because of its extremely low pH and high titratable acidity.²⁰ For extrinsic acids, reducing the frequency, duration and avoiding consumption between meals are far more important than reducing the amount of intake.²¹

The erosive power of carbonated and citric sports drinks can be enhanced by them being consumed during prolonged vigorous exercises, as dehydration results in reduced salivary secretion and hence less protection.²² Increased erosion can result from regular consumption of energy drinks as they usually are acidic and contain large amounts of caffeine which can reduce salivary flow.²³ Alcoholic drinks such as wines, ciders, cocktails and alcopops can cause the worst damage as they are acidic, strong diuretics and they can induce intrinsic acid reflux.^22,24 Nevertheless, preventive advice relating to these drinks may not be very popular to the patients. It may sound more appealing to advise consuming such drinks with main meals, reducing frequency and duration, using a straw and employing the protective regimen mentioned below.

Saliva has calcium and outstanding buffering ability, which promotes remineralization and reduces demineralization. We should recommend that patients consume dietary acid with a main meal when the saliva is abundant. Inbetween meals, salivary flow can be stimulated by non-fruity, sugar-free chewing gum. Mouthrinsing with antacid tablets, sodium bicarbonate or baking soda solution immediately after intrinsic or extrinsic acid attacks can neutralize the residual acid. This will minimize the erosive damage.²⁵ When hydroxyapatite is combined with fluoride to form fluoroapatite, the critical pH decreases.²⁶ This favours remineralization and disfavours demineralization. Therefore, regular topical fluoride application is indicated for patients with higher risk of TW. Topical fluoride can also be used to improve dentine hypersensitivity in NCCLs. Sensitive toothpaste and Tooth Mousse (GC) should be recommended to this group of patients.²⁷ A coating with a dentine bonding agent may protect the tooth substance from acid attack and may reduce hypersensitivity.²⁸

Smoking and drinking habits, stressful lifestyle, medications, medical or psychological conditions can contribute to sleep bruxism.¹⁴ Hard acrylic occlusal splints can reduce further attrition for confirmed cases. On the other hand, soft nightguards may increase the activity of the masseter muscle after long term wearing.¹⁴ They are not suitable for patients with developing dentition. In addition, the full coverage design hinders the post-erosion remineralization. It is also plaque retentive, which increases the periodontal and caries risk.

Toothbrushing within 30 minutes of extrinsic or intrinsic acid attack is generally not recommended.²⁹ Brushing with excessive force may be avoided by using electric toothbrushes.³⁰ Using a softer toothbrush instead of a harder one does not necessarily reduce abrasion.³¹ As mentioned above, toothbrushing with toothpaste cannot solely cause significant NCCLs. Any modification of a good brushing habit may reduce its effectiveness. To avoid further damage, we should choose a less abrasive restorative material when restoring an occlusal surface opposite to a worn tooth. Direct composite resin is the first choice as it is tooth-coloured, conservative, strong and low abrasive. Indirect restorations with porcelain surface can achieve the best aesthetic outcome but they are more abrasive than metal alloys and monolithic zirconia.^32,33

The preventive regimens will slow down the TW process. Hopefully, when the patient gets older, the cumulative BEWE score moves relatively horizontally across the age-related RAG grid. That is when the condition moves away from the red pathological TW zone (Figure 12).

Red and amber management pathways – Step 3. Review and monitoring

As mentioned in Table 12, the periodontal, caries and other disease risks, including TW, should be regularly revised. This is also a good time to reinforce the preventive advice and carry out a new diet analysis. The minimum review intervals are two years for TW-Amber and one year for TW-Red. Barlett states that inadequate sensitivity of the BEWE makes it unsuitable for monitoring purposes.⁶ Barlett advises the use of TWI and study models to monitor TW. However, the study models can cause storage and damage problems.¹⁹ Digital models taken by the CAD/CAM technology offer a good alternative to this option. Digital photographs (Figures 13a and b) can also be used to monitor TW. They are relatively inexpensive and easy to share. Moreover, they enable instant preview, visual and colour comparison.

Restorative and prosthetic considerations

During restorative and prosthetic treatment planning, a GDP should weigh up the possible harmful effects of these interventions against the damage from alternative treatments or no treatment. Specialist referral should be considered when the complexity is outside one's ability.

The BEWE-RAG TW screening system was not designed to make a diagnosis, therefore restorative and prosthetic treatments were not included in the management pathways. Operative interventions should only be prescribed on an individual basis according to the full TW charting and diagnosis. Take TWI as an example, lesions of scores 0, 1 and 2 do not need to be restored. Isolated TWI scores 3 and 4 usually do not need any treatment except for their complications. On the other hand, more extensive TWI scores 3 and 4 may require operative interventions.

Conclusion

Tooth wear has become an important dental condition, affecting many of the young generation. The BEWE-RAG tool simplifies the screening process and enables early identification of pathological TW. This can be easily done in a primary care setting. The associated management pathways assist a GDP to reach a sound diagnosis and evaluate the current risk. Early prevention and progress monitoring will avoid further deterioration. Nonetheless, the proposed screening tool may require further improvements and research to prove its validity.