Introduction

The exact role and importance of dental appearance remains controversial within the dental profession and society at large. The pursuit of facial beauty has intrigued artists, philosophers and dentists for generations. Just as artists argue about their views on art and some architects have strong views on buildings, so it is that many patients and dentists have strongly held opinions on what constitutes dental beauty. Some patients and their dentists prefer the natural dental appearance, while others prefer the 'very white, very even' appearance which has become more popular recently. Ultimately the individual patient should have the final say on what they prefer as their dental appearance, but achieving this is often fraught with various difficulties including interpretive, psychological, ethical, artistic, technical and legal problems. Various articles in the popular and dental press, as well as images in films or on websites have heightened patient expectations by drawing attention to what is possible to achieve with cosmetic dentistry interventions. There is little doubt that cosmetic dentistry, if performed skilfully on the right patients, at the right time, for the right reasons, can be life enhancing for many people.

Cosmetic dentistry has become the popular term both within professional and patient domains and is defined as procedures that are provided primarily to improve the appearance of the teeth, mouth and face. While standard dental treatment often helps to improve the appearance of diseased teeth, what is of serious concern now are unnecessarily destructive procedures which appear to be increasingly provided on largely sound, or mainly intact, teeth in order to conform to a supposedly 'cosmetically desirable' ideal, but which are biologically risky and offer no obvious long term functional benefits (Fig. 1).

Figure 1: This 17-year-old patient was provided with four veneers on her upper incisors for her birthday.
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Despite poor oral hygiene, having numerous cavities and teeth with unrestorable decay a dentist was only keen on providing her with 'cosmetic' dentistry. Unfortunately, numerous teeth were extracted subsequently and she was provided with a denture. Note the marked gingival inflammation associated with the veneers

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The procedures that are promoted and used vary in the levels of their invasiveness. They range from the minimalistic approach such as straight forward changes in colour, which can be achieved by bleaching techniques, through bleaching and bonding with direct resin composite, to the provision of multiple porcelain veneers or crown restorations (Fig. 2a and 2b).1,2,3,4,5,6,7

Figure 2: a) Upper central and upper right lateral incisors presenting with loss of vitality subsequent to accidental trauma and tooth surface loss.
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The patient was concerned at the discolouration of the teeth and reduced height of the crowns. b) Endodontic treatment was provided for the central and upper right lateral incisors. This was followed by internal-external bleaching and composite restorations at an increased occlusal vertical dimension. Posterior contacts were relinquished within a year of provision. Photographs courtesy of Alex Falanga, Specialist in Endodontics Kings College Hospital

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At the extreme end of such approaches are those advocating the elective removal of compromised teeth in order to place implants because it has been suggested that implants are 'more predictable'. This is a view that has become increasingly questioned (Fig. 3).8,9,10,11

Figure 3: a) This patient initially underwent crown restorations on the upper central incisors which subsequently failed.
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The subsequent post and core restorations failed resulting in extraction. Implants were placed with the aid of a block graft from the chin. The graft failed. In a vain effort to harmonise her teeth the upper right and left lateral, canine and first premolars were also crowned or veneered. b) Unfortunately all the teeth with extra-coronal restorations presented with pain soon after cementation. Six previously intact teeth were accessed (arrowed) and root canal treatment provided. The patient sought psychological counselling as a result of her experiences. c) OPT illustrating the numerous previously intact teeth either root canal treated or accessed for future endodontic treatment

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Orthodontics is one recognised way of dealing with problems of misplaced and unattractive teeth. The extraction of teeth, or significant tooth stripping for the purposes of space creation for orthodontic alignment is an accepted, different type of destruction, but if the result is unstable, or relapses significantly, then the presumed long term cosmetic benefit may not prove to have justified the elective removal of tooth tissue.12 However, such approaches, if adequately discussed to obtain valid consent and stabilised, may well be preferable to massive destruction of multiple teeth for dealing with crowded or malaligned teeth.13

Terminology

The word cosmetic is derived from the Greek word 'cosmetikos' and strictly speaking means an adornment. In general, cosmetics used around the face are temporary, transient and superficial, such as lipstick or eye shadow. They have to be applied every time one wants that effect. Cosmetic products do not damage the surfaces on which they are placed and are readily reversible. The increase in popularity of supposedly cosmetic dental procedures, many of which are not benign, not reversible and often unnecessarily destructive of sound tooth tissue may, in part, be linked to fashion changes, where ultra-white, very even, big teeth are deemed to be a desirable fashion accessory, or adornment, in some countries and cultures.

Greater media coverage of dental and other oral cosmetic procedures has increased patient pressures on dentists to provide allegedly beautiful smiles.14 Many dentists with appropriate training and experience are able, willing and in some cases anxious, to provide whatever they perceive as being 'what the patient wants' in return for an adequate fee.14 A recent survey of members of the American Academy of Esthetic Dentistry produced notable results. Dentists surveyed perceived overtreatment as being the biggest threat to aesthetic dentistry provision (33%) followed by patients having unrealistic expectations (23%).15 The results from this study demonstrate an awareness within the profession of 'cosmetic dentistry' decisions which are heavily influenced by the media and patient expectations, but without addressing the required balance of conservation of sound tooth tissue for the patients' longer term function. This decision to provide such cosmetic treatment may be criticised further when it is known that dentists prefer much more conservative treatment for their own teeth when compared to that which they provide for their patients.16,17,18,19,20 Indeed when patients were asked on their preferences between direct composite and more destructive indirect veneers for 'cosmetic' improvement there was no difference in perceived improvement between the two modalities.21 Interestingly patients were shown to favour composite due to conservation of tooth structure, cost and the need for one visit for treatment delivery.21

The fact that there are often larger fees involved for the more destructive treatments and/or that the constructive aspects of the treatment are subsequently undertaken by a highly skilled ceramist in a laboratory may be conscious, or unconscious, influencing factors in some dentist's prescribing patterns for their patients. The right combination of trained and talented clinician and technician can indeed produce beautiful end results on appropriate patients. However beneficial the individual patients or their dentist might perceive these changes to be when first done these are likely to deteriorate, or have some problems, in the fullness of time. It is understandable that the publicly funded dental healthcare systems might well seek to minimise their exposure to these potentially great costs for remedial treatment later on for what can be perceived by them to have been unnecessary interventions in the first place (Fig. 4).

Figure 4: a) 30% of sound tooth removed for extended porcelain veneer.
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The veneer had debonded on a number of occasions and cemented. The patient presented having lost the veneer. b) As provision of a further veneer would have resulted in greater tooth tissue removal as well as reducing the presence of enamel to bond to a direct composite veneer was provided. The result was acceptable to a patient with high aesthetic demands

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However, it should be stressed that patients with congenital or acquired defects of the face and oral cavity (such as those problems caused by dental trauma, cancer or cleft lip and palate, hypodontia and developmental anomalies of tooth formation) clearly do require appropriate aesthetic and functional rehabilitation with the aim of improving speech, function, quality of life and aid integration into society and these should obviously continue to be treated in the publicly funded health services (Fig. 2).22,23,24,25,26,27,28

Risks of cosmetic dentistry complications

The longer term risks and comorbidities of the more invasive treatments such as preparations for porcelain veneers and full coverage or all ceramic crowns are biologically significant and can result in later serious problems that patients may not have been be adequately warned of, or have been made fully aware of the viable alternatives, before giving their permission for such treatment. Sadly, the need for root filings through ceramic restorations has become a common problem (Fig. 3b).29,30,31,32,33,34,35,36,37,38,39

In other words, there may well be serious issues of lack of adequately informed and therefore valid consent before unnecessarily destructive procedures are undertaken while the alternative, less damaging, options may not have been properly or fairly presented to the patient, discussed or adequately considered. Later disappointments due to pain, swelling, and infection or dissatisfaction with the appearance, ceramic chipping, loss of restorations or other complications may be sources of complaint or claims especially when the teeth were previously healthy and mainly intact.40 The 2013 figures from the Dental Protection show that consent and communication issues were major problems in both complaints and claims.40 Patients complaining about what they perceived to be unsatisfactory appearance outcomes and the collateral damage inflicted on the teeth to achieve this were also major sources of litigation.40 Other issues involving claims included dentists supplying misleading, or incomplete, information to secure treatment acceptance or of some dentists making exaggerated claims of having extra expertise in the field that could not be substantiated in a court of law.40 For instance, there is no GDC recognised specialist list in 'cosmetic dentistry' or 'aesthetic dentistry' and so seeking to persuade someone that there is such a list, or that one is on it could be construed as 'wilful mis-representation'.

Biological and financial costs

Allegedly 'just cosmetic' dental treatments (such as those required for ceramic veneers and crowns) can result in the removal of significant portions of healthy sound tooth tissue, with up to 30% of tooth tissue being lost extended for extended veneers and 62-73% for full coverage crowns (Fig. 5).41

Figure 5: All ceramic crowns removed from the upper central incisors after 8 years of service.
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Unfortunately, there was a limited amount of natural tooth tissue remaining

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This is a real concern, especially when the treated teeth are unrestored, or minimally restored, with no history of significant dental disease. Where such teeth are prepared extensively, the previously healthy dentition can enter a restorative cycle where the need for restoration replacement will result in further hard tissue removal. Given that sound enamel and natural tooth tissue is finite, this often unnecessary structural and biological destruction can lead to pulpal or periodontal problems and sometimes premature tooth loss.

Pulpal problems

Tooth preparation for ceramic restorations can result in irreversible pulpal damage due to the heat and physical damage produced during deep preparation of teeth previously unaffected by caries.42 Caries is a slow process which normally gives teeth time to lay down reparative protective dentine but intact teeth which are quickly and aggressively prepared get no such chance to protect themselves, especially in the pulpal horns or cervical regions. The damage involved in newly prepared teeth may well be further compromised during the temporisation stage of treatment and where this is inadequate it can allow microleakage with bacterial ingress progressing down the freshly opened dentinal tubules leading straight to the pulp. The toxicity of the temporisation material used can also provide pulpal insult (Fig. 6).43

Figure 6: These teeth were previously intact.
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The patient wanted lighter coloured teeth. The upper and lower teeth were all prepared for veneers. When these were deemed unacceptable by the patient increasingly more aggressive crown preparations were undertaken. The patient sued the original dentist as he had caused her significant pain and after three attempts had failed to satisfy her 'cosmetic' demands. These temporary linked crowns were over contoured and engaging interproximal undercuts for retention. Gingival bleeding and inflammation were detected as the restorations were uncleansable. The patient refused to return to the original dentist as he had 'overpromised and under-delivered'

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If loss of vitality results from the preparations, or from subsequent problems of microleakage the patient may experience a variety of co-morbidities. Acute pulpitis is likely to be painful requiring pulp extirpation and subsequent root canal treatment. Root canal treatment weakens the residual tooth tissue resulting in greater chance of future tooth fracture (Fig. 7).44,45 In some cases the pulpal 'blushing' or loss of vitality can result in tooth discolouration due to blood breakdown products being incorporated into the dentine.46 Where pulp vitality is maintained, symptoms such as chronic sensitivity can develop post restoration.47,48 This is often due to poor adhesive technique and the poor sealing of the restorative luting system. The loss of vitality and other collateral damage have been significant sources of complaints by patients after the provision of veneers, especially when the endodontic treatment subsequently undertaken is deemed to be suboptimal in a dento-legal expert's opinion.40 In this regard the standard of endodontic therapy in general dental practice gives further grounds for concern.49,50,51,52 Adverse outcomes are often difficult to defend mainly because the teeth would not have needed the endodontic therapy had they not had the destructive cosmetic dentistry procedures undertaken in the first place.

Figure 7
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Five root fillings required after bonded ceramic crowns on originally intact teeth

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Composite versus amalgam in posterior teeth for cosmetic reasons

Elective restoration replacement of dental amalgam with 'white fillings' of various direct or indirect types can also result in significant pulpal symptoms (Fig. 8). Pulpal problems have been shown to be more likely the use of composite as opposed to amalgam particularly in deep cavities.53 Pulpal inflammation has been shown to be more pronounced with the use of resin composite than with alternative restorative material choices.54 This is probably associated with gingival or salivary contamination of the adhesive or luting systems, or due to c-factor shrinkage in larger molar restorations, thereby increasing the likelihood of bacterial ingress deep down cervically close to the pulp.55 The imminent 'phase down' of dental amalgam, a material which has been proven to be more tolerant of suboptimal placement conditions than composite under similar circumstances has potentially serious pulpal and tooth retention implications for patients which ought not to be ignored.56,57,58,59

Figure 8: This patient requested the removal of an otherwise intact amalgam restoration and placement of a 'cosmetic white' filling.
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She developed acute pulpal symptoms soon after and presented with chronic apical periodontitis to secondary care

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Cosmetic dentistry and periodontal problems

The interface between veneers and crowns and the gingival margin can result in the development of inflammation which can result in periodontal defects (Figs 9 and 10).60,61,62,63 Over contoured restorations, residual cement and positive margins can result in plaque accumulation and thereby result in gingivitis, gingival recession or periodontitis, all of which can result in significant morbidity.60,61,62,63 Encroachment by the restoration into the biological width can result in chronic inflammation of the gingival margin.60,61,62,63

Figure 9
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Over contoured crowns resulting in significant spontaneous bleeding

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Figure 10: This patient presented with peri-implantitis, periodontitis, gingivitis, halitosis and caries associated with all the poorly contoured crowns.
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There was a sinus associated with the upper right canine

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Longer term biological and financial repercussions

Any dental restoration, including veneers and crowns, will require replacement in the future. Where teeth have been prepared extensively, especially when they have to be subsequently root canal treated, this may result in the restoration replacement becoming progressively more difficult to achieve satisfactorily due to a lack of remaining sound tooth tissue (Fig. 11).

Figure 11: Three teeth were extracted as a result of multiple ceramic veneers being placed on discoloured teeth five years previously.
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Note gingival recession and staining of composite luting cement

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These possible biological risks and complications need to be considered against a backdrop of significant financial outlay and time by the patient for the initial, usually private, treatment provision. Remedial work to correct any problems resulting from cosmetic dental treatment is also likely to result in further financial burdens in the longer term. This burden may fall upon the patient, the treating dentist, future dentists in that practice, other general dental practices, or on to secondary care specialist services to provide remedial treatment, or advice on its planning if this is not within their remit. One thing seems certain, however, that is that there will be further costs incurred by someone, sometime, and both patients and dentists need to be well aware of those likely issues and their future implications as part of the properly informed processes.

In the future, attitudes may well have hardened against some currently fashionable cosmetic treatments, which are often voluntary and unnecessarily destructive. Subsequently some dentists faced with the potential costs of consequent treatment could well encourage patients to pursue litigation to obtain funds for their remedial treatment. This is partly because the state system is unlikely to be particularly sympathetic about these issues, or be willing to prioritise funding for renewal or repair for what it might contend were elective aggressive cosmetic procedures.

The Francis report: consent and communication

These issues may have serious implications for dentistry when considering the Francis report relating to the duty of candour.64 This report states that all relevant information needs to be volunteered to persons who have, or may have been harmed, by the provision of services, whether or not the information has been requested and whether or not a complaint or a report about that provision has been made.64

Conclusions

It is the opinion of the British Endodontic Society, British Society for Restorative Dentistry, Restorative Dentistry UK, Dental Trauma UK, British Society of Prosthodontics and the British Society of Paediatric Dentistry that elective invasive cosmetic dental treatments can result in great benefit to patients but that these can also produce significant morbidities in teeth which were previously considered healthy. This is a worrying and growing problem that is preventable by using a biologically safer initial approach to treatment planning and it's provision wherever possible. Minimally invasive approaches, which are associated with lower risks and good fall-back positions, should be advocated and practised wherever possible as the first choice of treatment for patient seeking improvements in their dental appearance. In contrast, where teeth have large restorations the provision of an extra-coronal restoration is an accepted treatment option in order to protect the remaining tooth tissue. However the full range of dental materials – including sandblasted gold or other metals – as well as ceramic of various types should be considered carefully, especially in low visibility situations.

Patients seeking cosmetic dental improvement should be made fully aware of the associated risks, possible complications, the lack of permanence of restorations and their longer-term biological and financial costs. As is the case with other dental treatments neutral, sensible, considered language and information needs to be given to patients in advance and preferably in writing in order to obtain their properly informed consent for elective cosmetic invasive procedures. This should be the agreed basis for the acceptance of cosmetic dental treatment by these potentially demanding, but vulnerable, patients.