Patient preventive advice to mitigate signs and symptoms of tooth wear

Tooth wear can be defined as the ‘pathological, non-carious loss of tooth tissue’.¹ However, tooth wear can be physiological because some amount of tooth wear will occur throughout life.² Pathological tooth wear is more severe than what is expected relative to a patient's age, and involves ‘pain or discomfort, functional problems, or deterioration of aesthetic appearance’.³ Tooth wear has various aetiologies and can be caused by erosion, abrasion or attrition, or any of these in combination (Table 1).

The 2009 Adult Dental Health Survey reports a high prevalence of tooth wear in the UK, with 77% having at least some tooth wear on their anterior dentition. Overall, 15% of adults had moderate tooth wear (tooth wear that exposes an increased amount of dentine) and 2% severe (extending into secondary dentine). Moderate tooth wear had increased in the adult population since the previous adult dental health survey, from 11% in 1998 to 15% in 2009.⁵ This survery was conducted some time ago, but there is still cause for concern.

The prevalence of tooth wear is high and is presenting growing challenges for dental professionals. The treatment of tooth wear can be challenging and often involves complex restorative treatment and therefore, an important aim of prevention is to avoid this.³

Problems that often face patients with tooth wear include poor aesthetics,⁶ dentine hypersensitivity,⁷ loss of occlusal vertical dimension,¹ fracture of teeth or restorations and functional issues including difficulty masticating food.⁸ Therefore, tooth wear can be detrimental to a patient's quality of life and can impact on psychological wellbeing.⁹

Prevention has been advocated as a method of addressing tooth wear;⁶ however, there is a lack of comprehensive advice on a range of preventive interventions in tooth wear.¹⁰ The Department of Health's ‘Delivering better oral health’ guideline states that for preventive advice, there are ‘few clinical studies’ and evidence has ‘low certainty’.¹¹ This is coupled with increasing challenges for dental professionals, including the increasing prevalence,⁵ the ageing dentition of the population,¹² implications for a patient's quality of life¹³ and complicated restorative needs if left untreated.³ This warrants further research into preventive advice to address these shortcomings in evidence. This review provides a summary of current preventive strategies that can be easily communicated to patients to help prevent tooth wear in dental practice, based on the current best available evidence.

Methods of prevention: erosion

Toothpaste

Brushing with a fluoride toothpaste following an erosive attack, has been shown to significantly reduce enamel erosion compared to a fluoride-free toothpaste in clinical studies.^14,15 Furthermore, stannous fluoride toothpaste (1400–1450ppm F^-) significantly reduces enamel erosion relative to sodium fluoride toothpaste (1450ppm F^-)¹⁶ and stannous fluoride (0.454%) toothpaste also significantly reduces erosion compared to sodium fluoride (0.24%)/triclosan (0.3%) toothpaste in clinical studies.¹⁷ Stannous fluoride toothpaste (1450ppm F^-) provides a 93.9% improvement in protection from erosion compared to sodium monofluorophosphate (1450ppm F^-)/arginine.¹⁸ For dentine erosion, little difference in prevention was seen between sodium fluoride- and stannous fluoride-based toothpastes in laboratory studies.¹⁹ Encouraging the use of stannous fluoride products may therefore be useful advice; however, conventional sodium fluoride products are still beneficial.

If dentine hypersensitivity is present, stannous fluoride, NovaMin (Haleon), strontium acetate or arginine have been shown to occlude dentine tubules through toothbrushing, and offer various resistances to acid challenge in clinical studies.^12,20 If brushing is initially painful, dab-on with a sodium fluoride or stannous fluoride toothpaste has been shown to occlude tubules in laboratory studies and may help re-establish a normal brushing regimen.²¹ Tubule occlusion may reduce dentine hypersensitivity, a sign of tooth wear, clinically.¹²

Fluoride toothpaste, mouthwash and gel reduces mineral loss in both enamel and dentine in another clinical study,²² and combinations of these may benefit a patient's daily oral hygiene regimen.

Mouthwash

There is a significant decrease in erosion of enamel and dentine when stannous fluoride mouthwash (500ppm F-, 800ppm Sn²⁺) is used, but there is no significant effect on dentine hypersensitivity, which is a sign of tooth wear in dentine.²³ Despite these benefits, patients should be made aware that mouthwashes are best used at a different time to brushing.¹¹

Other

One randomized clinical study showed that casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) chewing gum lessens enamel erosion significantly. The difference between the CPP-ACP and the control groups was significant, although the difference between the CPP-ACP and non-CPP-ACP gum was not significant.²⁴ However, the sample size of eight was small, so further research is needed. Chewing gum can be of benefit to patients, although it should be sugar free²⁵ and supplement, rather than be a substitute for a standard oral hygiene regimen.

Extrinsic erosion

Clinically, consumption of extrinsic acids has been associated with non-carious cervical lesions (NCCLs),²⁶ and dietary acids are significantly associated with erosion.²⁷ In addition, erosive tooth wear significantly increases with increasing frequency of carbonated soft drink consumption.²⁸ Consuming acidic drinks with meals and between meals, holding drinks in the mouth and taking more than 10 minutes to drink acidic drinks is significantly associated with erosion, as shown in a clinical case control study.²⁹ Further studies have found that frequent consumption of fresh fruit and isotonic/energy drinks is associated with erosion,³⁰ as is fruit juice.¹¹

Alcohol has been demonstrated to cause erosion. This can be linked to the acidic nature of the alcohol itself, for example wine or cider, the increased episodes of vomiting associated with alcohol consumption, an increased risk of GORD and the often-erosive mixers used in alcoholic beverages.³¹ The GDP should always take a thorough alcohol history from the patient, including number of units of alcohol consumed per week and the types of drinks consumed. Dentists should provide patients with advice regarding alcohol consumption, and inform patients that the NHS currently advises adults drink no more than 14 units per week.³⁴

There are other dietary sources of extrinsic erosion to be considered. Foods that are particularly acidic, such as pickles, vinegar and brown or tomato sauce, can contribute to erosion. Furthermore, some yogurts and even salt and vinegar crisps are potential sources of erosion.³³

Dietary advice in line with the Department of Health¹¹ should be given to help patients reduce erosive risk. Patients should be encouraged to reduce the frequency and volume of acidic drink consumption and not hold or swish the drinks in their mouth. The use of a straw placed posteriorly while drinking may provide additional protection, although this should not be given as licence for excessive consumption.³⁴ Despite fruit being a risk factor for erosion, patients should be encouraged to eat a balanced diet in line with the Eatwell Guide.³⁵ It would be unwise to discourage eating fruit, therefore limiting fruit to mealtimes is advisable. In relation to this, a clinical randomized study has demonstrated that a personalized diet plan lasting from 3 to 5 minutes, with an advice sheet, significantly reduces dietary acid consumption and erosion³⁶ and therefore, sufficient discussion with the patient on diet is important.

Intrinsic erosion

The largest study conducted on tooth wear, in Europe, showed that gastro-oesophageal reflux disease (GORD) is significantly associated with erosive tooth wear.³⁰ It has also been associated with smoking, alcohol, caffeine, spicy food, carbonated drinks,³⁷ obstructive sleep apnoea and obesity.³⁸ A GDP may be the first person who sees active palatal tooth wear, a sign of intrinsic erosion, especially if there is possible ‘silent acid reflux,’ which may have risks for the oesophagus and general health.¹⁰ A GDP should therefore always investigate further if GORD is suspected, and refer the patient to the general medical practitioner (GMP) for investigation (with appropriate consent from the patient). The GMP may recommend conservative measures to manage the GORD, such as diet modification to avoid foods known to be associated with GORD. Further measures include medications, such as proton pump inhibitors, and if the more conservative measures fail to control the reflux, then surgery may be offered.³⁹

The GDP can also provide dietary advice to the patient because certain foods and drinks are known to be reflux promoting, such as chocolate, caffeine, alcohol and foods high in fat.⁴⁰

Eating disorders are also known to contribute to erosion.⁴¹ Some eating disorders can lead to increased/frequent vomiting, such as bulimia. Others, such as binge-eating disorder, may contribute to erosion owing to the increase of erosive food/drinks in the diet. The palatal surfaces of the maxillary incisors are often affected by repeated vomiting. Other signs include trauma on the palate and frequent brushing to mask the effects of the vomiting. GDPs are in a position to pick up signs of eating disorders and should raise these concerns sensitively with the patient. Dentists can provide oral hygiene advice, fluoride application, and recommendations can be made to use sugar-free chewing gum to reduce acid erosion by stimulating salivary flow. Patients should be advised to not brush immediately after vomiting and perhaps be advised to rinse with water after vomiting. Dentists should offer support to patients and encourage them to seek advice/treatment with their GMP.⁴²

Abrasion

Toothbrushing after erosive attack

Enamel erosion studies have shown that there is no significant benefit for waiting between an erosive attack and brushing,^14,15,29,43 even when adjusted for diet. Furthermore, there is no significant benefit of brushing before an erosive attack.¹⁵ However, in dentine, acid can cause the protective smear layer to be lost, leading to patency of the dentine tubules if the dentine surface is exposed. This may mean, especially for exposed areas of dentine, that these surfaces are more vulnerable to toothbrushing immediately after an erosive attack.⁷ Some studies still recommend not brushing immediately following an erosive attack⁴³ and to leave 1 hour between an erosive attack and brushing,⁴⁴ as it takes approximately 40 minutes for the pH of the mouth to return to normal.⁴⁵ Pragmatically, it would be pertinent to still advise patients to avoid brushing immediately after an erosive attack.

Toothbrushing

A vigorous toothbrushing habit is associated with non-carious cervical lesions (NCCLs)²⁶ and frequency of toothbrushing is significantly associated with NCCLs.²⁷ One study concluded that rotating electric toothbrushes did not cause any hard tissue damage, and are considered safe.⁴⁶

However, a large European study found the use of an electric toothbrush to be a significant risk factor for erosive tooth wear^12,30 and this may be related to brushing hardness, bristle type and tooth surface. There is little justification at present to advise patients to avoid electric toothbrushes until further evidence is gathered, moreover electric toothbrushes can have pressure sensors to prevent excessive force being applied.¹² A vigorous toothbrushing habit may be easier to manage if the patient is warned by the sensor, provided the sensor is triggered at an appropriately low force that reduces tooth brush bristle bending,¹² whereas this would not be noticed if using a manual toothbrush until abrasion had occurred.

Other sources

There are other sources of abrasive tooth wear for which the general dentist needs to be aware. Pica is an eating disorder characterized by the eating of ‘non-nutritive substances.’ This can include soil, stones and plastic objects. It is particularly common among small children, those with learning disabilities and pregnant women. The GDP should take a detailed history from the patient and, as with other eating disorders, it is advisable for the patient to be assessed by their GMP.⁴⁷

Bruxism and attrition

Bruxism may be characterized as either awake or nocturnal and strictly speaking has a different definition to attrition, and typically occurs as a result of parafunctional activity causing trauma and grinding of tooth surfaces. There may, nonetheless, be some signs of attrition, with edge-to-edge occlusal wear occurring, where the tooth surfaces meet.

A patient who has awake bruxism is often aware of possible signs, such as jaw clenching, and there is evidence that stress/anxiety may be associated.⁴⁸ Nocturnal bruxism is less prevalent than awake bruxism and is associated with a neurological cause when asleep, triggering ‘rhythmic masticatory muscle activity’.⁴⁸

Further contributary factors to attrition included the use of recreational drugs, such as ecstasy.⁴⁸ Alcohol and nicotine have also been associated with bruxism.⁴⁹ The GDP should ensure to always take a thorough social history from the patient and advise on the link between attrition and recreational drugs, alcohol and nicotine. Again, liaising with the patient's GMP is advised.

Sleep hygiene measures such as ensuring the patient goes to bed at a similar time each night, avoiding caffeine and relaxing before bedtime have been suggested, although there is little evidence of their efficacy.⁵⁰ Irreversible adjustment of the occlusion is not indicated as a treatment modality for bruxism.⁵⁰

Splints

A randomized clinical study showed that biofeedback splints were significantly better than occlusal splints at reducing the number of bursts and total duration of bruxism activity every hour, and the average and maximum durations of any activity in patients with sleep bruxism.⁵¹ Reducing the contact between the tooth surfaces via a splint is likely to be beneficial, and there is evidence to suggest that the conventional occlusal splint can protect the teeth from tooth wear.⁵² The biofeedback splint is likely to be difficult to provide in practice compared to standard occlusal splints. Furthermore, biofeedback devices can cause a disruption of sleep. This in turn may present more problems for the patient.⁵⁰ Therefore, dental practitioners should provide at risk patients with occlusal splints until further research is gathered.

There is currently little evidence to suggest whether an upper or lower splint is more beneficial, although some clinicians have anecdotally advised an upper splint so the forces can be distributed across the hard palate.⁴⁸ Hard splints may anecdotally reduce sleep bruxism; but importantly have a role in protecting the teeth (and restorations) from tooth wear or fracture caused by bruxism. Stabilization splints can also be constructed. Any splint must be constructed with full occlusal coverage to reduce changing the occlusion orthodontically and ensure canine or anterior guidance.⁵⁰

Botulinum injections

A study demonstrated that masticatory muscle intensity could be reduced by botulinum injections for at least 12 weeks, although the treatment did not reduce the incidence of rhythmic masticatory muscle activity or its duration.⁵³ Participants were only studied for two nights over a 12-week period, therefore long-term implications are unclear and further studies with longer follow-up periods are required. Therefore, this is a short term measure, and there have been concerns raised regarding the side effects of this treatment, including osteopenic changes at the site.⁵⁰

Clinical recommendations

Clinical recommendations are given in Table 2.

Contribution of work

These recommendations add to the existing evidence base from ‘Delivering Better Oral Health’¹¹ and accounts for some current gaps in knowledge. Future implications include providing a simple and memorable set of clinical recommendations for dental professionals' education, that can be used to provide advice to patients regarding tooth wear prevention.

Conclusion

Preventive advice can be used as an effective method of mitigating tooth wear in patients and should be provided by dental care professionals. However, this requires ongoing education to the dental team on best practice. Additionally, further high-quality research is required to provide stronger evidence regarding tooth wear prevention, particularly in abrasion and attrition.

Limitations

Owing to the available higher quality research, this article focuses mainly on erosion. Further research regarding preventive advice for attrition and abrasion is needed. Abfraction was not covered because there is limited clinical evidence to support its existence, and erosion and abrasion are more likely to contribute to NCCLs.