Letters

Staining from silver nitrate

Sir,— We wish to highlight an unusual case where hypocalcified enamel became stained with silver nitrate subsequent to its use to achieve haemostasis during soft tissue biopsy.

A 16 year old girl was referred by her GDP for the excision of an unsightly papillomatous swelling in the region of the interdental papilla between the right premaxillary incisors, which developed following a course of orthodontic treatment. Examination revealed a 6 mm papillomatous type lesion with a strawberry-like appearance at the dental papilla between the right premaxillary incisors. The lesion was mobile with no evidence of periodontal pocketing. The patient underwent excisional biopsy of the lesion under local anaesthesia outpatient care; during the procedure a silver nitrate stick was used to achieve haemostasis. The patient subsequently developed a bluish staining (fig 1) at the gingival aspect of both incisors.

Figure 1

Staining in the upper central and lateral caused by the silver nitrate.

The patient was referred to a consultant in restorative dentistry whose examination revealed that the enamel at the gingival aspects was very thin and decalcified, consistent with tooth wear due to erosion. The staining was attributed to the uptake of silver nitrate by the porous enamel at the cervical margins adjacent to the biopsy site. The patient underwent scaling, polishing and micro abrasion which produced some improvement in appearance of the affected teeth. The patient was also offered further treatment including air abrasion and veneers. Although the use of silver nitrate is a method of achieving haemostasis, this case highlights a limitation of its use. A careful history, examination and assessment of enamel status is important before deciding to use chemical agents to achieve haemostasis in procedures on the adjacent tissues.

Other methods of achieving haemostasis should be considered in those situations where the enamel structure may have been compromised. Alternatively, physical protective barriers such as dental rubber dam could be used to protect the dental hard tissues from staining.

Z. Sadiq, C. Moss and J. Stocker

Peterborough

Mercury amalgam-gold crown interaction

Sir,— A patient attended surgery recently for a routine inspection. A battery driven/electric toothbrush was advised in order to reduce gingival recession and abrasion caused through too vigorous manual toothbrushing. Accordingly, the patient bought one and used just a few hours after inspection.

On self examination, the patient noticed that a gold crown in the lower right quadrant, which is adjacent to a silver amalgam, had lost its bright, highly polished surface, and acquired a tenacious, greyish appearance, akin to 'brushed' stainless steel. No such change occurred on any other gold crowns in the patient's mouth even though they are adjacent to other silver amalgams. On polishing the affected gold crown, the original yellow surface was exposed, but appeared duller. We could speculate that the new electric tooth brush had possibly liberated something from the silver amalgam, which was subsequently taken up by the gold crown; it was also noted that the amalgam in question had subsequently taken up a rather pitted almost granular appearance.

The amalgam and gold surfaces in the patient's mouth are all of different ages and may therefore be at least subtly different in their composition. The amalgam adjacent to the affected gold crown has been replaced with a gold inlay with no further effect to the gold crown. I would be interested to hear whether anybody else has come across this phenomenon, and also for any speculative explanations. There is also a toxological dimension to the observation. A few free standing milligrams of the amalgam filling and a scraping of the dull coat deposit from the gold crown are available to interested parties for analysis.

D. M. Cowen

Keighley

Paediatric dentistry

Sir,— The recent papers investigating the outcome of dental caries in primary molars raise important and fundamental questions about dental services for children in the United Kingdom and the authors are to be congratulated for taking the first steps into this potentially controversial area.^1,2 I have been asked to co-ordinate this consensus response on behalf of the Consultants in Paediatric Dentistry Group.

The key conclusion of both papers, i.e. that restorative interventions provided within the General Dental Services in the UK do not appear to influence outcome, is hugely disappointing, but sadly comes as little surprise to those within the Specialty of Paediatric Dentistry. That effective restorative interventions for primary teeth exist is not in doubt. Stainless steel crowns, for example, have demonstrated excellent longevity in a number of studies.³ The vital pulpotomy technique has achieved over 90% success in virtually all studies that have investigated its efficacy.^4,5 In addition, contrary to the studies currently being discussed, there is some evidence that a small minority of practitioners within the GDS do achieve a good outcome.⁶ However, the fundamental question is this: why are the levels of success reported in studies of individual techniques not being translated by the majority of primary care practitioners into effective treatment outcomes for children in the UK?

There can be little doubt that the authors' assertion that 'effective methods of preventing dental caries at the individual and public health levels need to be expanded' is correct. However, in spite of considerable efforts to promote the preventive message, dental caries is still at epidemic proportions in the young children of our country and there has been little change in its prevalence in the primary dentition for nearly two decades.

In many parts of the country around 50% or more of 5 year-old children have dental caries experience, and, on average, those with decay have around four or more decayed teeth by this age.⁷ The second of the two studies in question reinforces the findings of a previous study which demonstrated that dental caries in children is associated with a high morbidity.⁸ It is also important to recognise that these studies employ design features (i.e. retrospective record analysis) which are likely to result in an undercounting of adverse events. The full picture may be significantly worse.

There is clearly an urgent need to ensure that, where preventive strategies have failed to stop the development of clinical disease, effective treatment interventions are available. One potential route for primary care dentists is to refer young children with caries to a specialist centre. However, following implementation of the recommendations of the joint report of the CMO and CDO on the provision of dental general anaesthesia (DGA) services, paediatric dentistry services in many parts of the country are already under severe pressure.⁹ While there has been a centrally driven shift of service provision from the primary care sector to the acute hospital trusts, there has not been a similar shift in central funding. Inability to expand hospital-based services to meet demand has resulted in children with dental pain having to wait for long periods of time before receiving treatment. Waiting time to consultation is already more than one year in some centres.¹⁰ Some of these children can be treated using alternative approaches (such as conscious sedation) but access to such services is often very limited. For a proportion, especially the very young, DGA remains the only appropriate management strategy. It is essential that these children have rapid access to dental conscious sedation and DGA services and it is especially important that the planning and provision of dental care at these centres is of the highest quality to minimise the risk of repeat DGA. ¹¹

Urgent action is needed to improve the quality of dental care available to young children in the UK. This will require an open and frank debate about how effective dental care for young children with caries is best provided. Such debate will need to be informed by carefully designed prospective studies. Specifically, we need to address the following challenging questions:

• Why is the success of restorative interventions currently provided in the UK GDS apparently so poor when effective, evidence-based interventions are available?

• Is the GDS the best place to provide dental treatment for a young child with caries or would improved access to specialist paediatric dentistry services lead to better outcomes?

• Does our current approach to DGA and conscious sedation services for children need to be re-considered?

Now that the anaesthetic safety issues related to the delivery of conscious sedation and DGA have been fully addressed, what can be done to improve the quality of the dental care provided at the time of these interventions, hence improving outcome and reducing the need for repeat procedures? It is imperative that we respond to these challenges without delay.

S. A. Fayle

Leeds

Rubber dammit!

Sir, – In response to the suggestion by Dr T Nguyen that a bilateral ID block may make treatment easier in some cases I would say. . . . rubber dammit! The claim that the treatment was much safer must be challenged. A bilateral ID block must surely leave a patient more vulnerable to accidental trauma to the anterior 2/3rds of the tongue or lip either by the dentist or the patient. The patient would also be socially incapacitated after leaving the surgery. The use of rubber dam is the best way of protecting the patient from soft tissue damage, inhalation/ingestion of debris and instruments and the unnecessary over-administration of drugs. It also enhances the field of operation thus improving the quality of work done. Other systems, such as Aqua-Vac, exist to overcome the difficulties described if the placement of rubber dam is impossible.

P. L. V. Martin

London

Ethical selling

Sir, – The leader entitled Ethical selling - what is it? (BDJ 2002; 192: 423) highlighted many of the qualms that practitioners have when broaching the question of selling specific clinical services. The final paragraph, which you quite rightly identified as crucial, raised the question of what patients want and what they need not always being the same thing. Once patients have been given treatment options they often ask 'is this treatment necessary?' An explanation I give is that if the patient wants the end result then the treatment is necessary. If, on the other hand, the patient does not want the end result, then the treatment is unnecessary. I suggest it is therefore the patient's responsibility to decide on necessity rather than the clinician's.

F. Haines

Truro

Teeth whitening debate I

Sir, – I am totally baffled by all the issues surrounding tooth whitening. Could history repeat itself with court cases concerning possible future adverse effects like those of fluoride which can cause tooth mottling? Are tooth bleaching agents cosmetics or pharmaceuticals? Is bleaching necessary treatment for the majority of patients who request it? What are the risks and does benefit outweigh risk? A significant number of my patients have made enquiries about this treatment and I would like to be able to give clearer advice backed by scientific evidence. Is DIY home bleaching considered to be safe and legal? If so, Argos sell a Yotuel complete teeth whitening system for only £324.99 on page 532 of its latest catalogue!

J. Fieldhouse

Weston-super-Mare

Linda Wallace , BDA's Director of Professional Services says:

The reviews show that the technique is safe and effective, but unfortunately, when the UK legal position was tested, the House of Lords decided that the supply of the products was contrary to the EU Cosmetics Directive and therefore illegal. It is a legal technicality which turns on the classification of such products as cosmetics and the limit on how much hydrogen peroxide a cosmetic product can contain. The BDA is trying to resolve the issue both in the UK and Europe.

Teeth whitening debate II

Sir,— I am writing regarding the current situation with regard to dentists using tooth bleaching in their practices. I understand that my predecessor has indicated that dentists are allowed to use techniques of external and of internal bleaching of teeth in any way provided that the patient or their carer agrees. These techniques themselves are not illegal. The highly publicised legal case revolved around the supply of these products and whether they are medical devices or cosmetic products.

It is the Government's view that they are cosmetic products. Notwithstanding that, the Department of Health would not seek to interfere with a dentist's therapeutic decision to utilise a bleaching technique where a dentist considers this to be in the best interests of the patient's overall oral health care.

Margaret Seward

Chief Dental Officer

The York Report

Sir,— The Report identifies a toxic effect of fluoride from all sources of intake, as fluorosis of aesthetic concern. Self-assessment of the cosmetic appearance of such compromised teeth has not been investigated. ^12,13 People can be expected to have views about the appearance of their own teeth. There is every indication that the background variables of gender, age, and social class are of importance when discussing dental appearance and it is probable that ethnicity will also play a role. The scale of the problem of blemished dentitions is described in the current Adult Health Survey where 27% of dentate adults are dissatisfied with the appearance of their teeth, and the most common reason given (48%) for that dissatisfaction is colour.¹⁴ These findings tend to show little difference in attitude towards dental blemish among men and women. However detailed study shows concern for dental appearance to be more important to dentate women than to dentate men.^15,16 Further, men tend to be less concerned with the appearance of their teeth having significantly more missing teeth, crown defects and discolouration than women.¹⁷ With regard to age, younger people prefer white teeth when compared with their elders, while the greatest concern for dental appearance was apparent in the middle aged (26-59 year olds) ^17,18

Social class is also a factor. Paradoxically, even though the lower socio-economic groups are seen to traditionally neglect their teeth, they have a greater preference for white teeth, and a greater interest in dental appearance than those with higher levels of education.^18,19,20

There is a balance to be struck. The trade-off between reduced incidence of dental decay and increasing degrees of fluorosis culminates in the Report's proposal to reduce levels of fluoride from 1.00ppm to 0.80ppm. Given a favourable outcome to the proposed efficacy study, then further judgements could be made about the desirable concentrations of fluoride additive to be used.

The general public has an increasing interest in dental appearance. Proper consideration of the unwanted effects of fluoride on the broad sub-groups of our population can only enhance our standing within the scientific community. It will also help us put our considered measured case to, what in water fluoridation terms, is a educated electorate.

M. Frazer

Twickenham

Aphthous ulcers

Sir, – Many of us have had the displeasure being afflicted by aphthous ulcers, although some of the suggested causes of aphthous ulcers have been a genetic predisposition, link with natural immunity, mouth injury following dental procedures or aggressive tooth cleaning, when the tongue or cheek is bitten, stress, dietary deficiencies such as iron, folic acid, or vitamin B12, menstrual periods, hormonal changes, food allergies and drug treatment, there have been no suggested preventive measures.^21,22,23

Our personal observations over a period covering the last twenty years suggest that there may be a link between the consumption of carton orange juice and aphthous ulcers. We have observed thirty-six subjects of either sex between the age of 18 to 73 years who had recurrent aphthous ulcers.

All consumed a quantity of orange juice daily. On being asked to refrain from further orange juice consumption, ulcers resolved in all subjects between one to five days without the use of any medication.

Interestingly, the relapse occurred only on the resumption of the use of carton orange juice. Equally, no ulcers occurred on eating fresh oranges, Halib-orange tablets or drinking freshly prepared fruit juice. Our observations suggest that there may be a link between the aphthous ulcer formation and consumption of carton orange juice, either due to a direct causal link or indirect aggravation of the buccal mucosa in predisposed subjects.

The causative agent in the carton orange juice is not known.²⁴ Therefore, it would be interesting to know if any other readers have made this observation.

A. Ghelani, S. Mastana and A. Samanta

Loughborough

A word in your ear

Sir, – I was intrigued by your news item (BDJ 2002; 193: 130) concerning a prototype tooth implant capable of transmitting audio messages to the inner ear via the jaw bone.

The ability of the teeth to act as a sound conduction apparatus has, of course, been recognised for many years.

Volcher Coiter (1572) observed that the sound of a musical instrument becomes louder when clenched between the teeth and Joseph Guichard Duverney explained the mechanism of bone conduction of sound in 1683.²⁵

Interested readers may care to look up a brief case report I wrote when a struggling registrar in 1974.²⁶

J. Townend

Chichester

Gingival recession

Sir, – I was interested to see the article by Messrs J. J. O'Dwyer and A. Holmes showing gingival recession due to a lip stud. The clinical picture is very similar to that seen where there are crowded lower incisors, where one lower incisor is labially displaced.

The probable reason in both cases, is pressure from the lower lip against the labial bone induces osteoclasis and the resultant gingival recession. In the case of the lip stud the artificial lump of metal exerts localised pressure against the bone labial to the incisor. I suspect that if the lower incisors had been spaced the tooth in question would have moved lingually and there would have been no recession of the gingivae.

R.T. Broadway.

Winchester.

The authors respond:

The aetiology of gingival recession is complex and multifactorial. The literature review we carried out prior to writing the article established a link, which for obvious reasons we wished to highlight, between trauma caused by tooth brushing and gingival recession. ^{27, 28, 29}

This evidence is however, gathered from mainly retrospective cross-sectional studies and case reports. There is no doubt that gingival recession occurs much more readily when there is an underlying bony deficiency.

Such deficiencies can be caused by orthodontic treatment. As we stressed in the article, however, dehiscence is much more likely to occur during orthodontic therapy when there are no teeth extracted and the lower incisors have been proclined, this was not the case.

Warfarin and extractions

Sir,— The North West Medicines Information Centre recommends that warfarin does not need to be stopped before dental surgical procedures providing the INR of the patient is below 4.³⁰ To investigate if warfarin can be continued during dental extractions we recently performed a randomised controlled trial at Morriston Hospital in Swansea.³¹ 109 patients completed the trial (see news item pg 306).

The incidence of bleeding episodes in the 57 patients who continued warfarin during dental extractions was higher than the 52 patients who stopped their warfarin two days before extractions, but this difference was not significant. Only 2 out of 22 patients who had minor post-operative bleeding failed to control the bleeding at home by biting on gauze squares.

These two patients attended hospital where the bleeding was stopped by local treatment of the extraction socket. Therefore, although there may be some increase in the number of patients experiencing minor post-operative bleeding when wafarin is continued, this does not appear to be a clinically important problem.

Ranstrom et al found that using tranexamic acid mouthrinses in patients who continued taking warfarin at the time of dental extractions reduced postoperative bleeding.³² However, tranexamic acid does not have a product licence for use as a mouth rinse in the UK and can be used only for named patients.³³

Furthermore, the North West Medicines Information Centre advise that Tranexamic Acid mouth rinse should not be used in primary dental care.³⁰ If patients could be treated without altering their anticoagulant regimen, then it is possible that most dental extractions could be performed in general dental practice on the same day as regular INR blood monitoring. This would often be more convenient and quicker for the patient, cost effective, and help to reduce hospital waiting lists. It remains to be established if our study's findings can be translated to general dental practices.

A. J. Gibbons, I. L. Evans, M. S. Sayers, G. Price, H. Snooks, A. W. Sugar

Swansea