A Group of General Dental Practitioners' Views of ...

The Hall Technique and Primary Dental Care

A Group of General Dental Practitioners’ Views of Preformed Metal Crowns After Participation in the Hall Technique Clinical Trial: A Mixed-Method Evaluation Nicola PT Innes, Zoe Marshman and Ramola E Vendan

Key Words: Hall Technique, Preformed Metal Crowns, Stainless Steel Crowns, General Dental Practice, General Dental Practitioners

Aims: The aims of this study were to investigate and describe the

views of a group of general dental practitioners (GDPs) on their use of preformed metal crowns (PMCs) with the conventional method and the Hall Technique. The practitioners involved had previously taken part in a clinical trial of the Hall Technique. Methods: The dentists’ views were explored using a semi-structured interview (transcribed and analysed using a framework approach) and their use of crowns investigated (for conventional and Hall Technique) using a short questionnaire. Results: Fourteen out of 17 dentists who participated in the trial were interviewed and completed the questionnaire. Prior to the

INTRODUCTION The conventional method for placing preformed metal crowns (PMCs) on pr imary molar teeth has remained largely unchanged since they were first introduced to paediatric dentistry in the 1940s.1,2 This involves stages similar to those carried out for the placement of a plastic restoration, including administration of local anaesthesia (LA) and removal of infected dentine. To allow the PMC to be fitted, a high-speed handpiece is then used to prepare the mesial and distal sides of the tooth, before reducing the occlusal height by around 2 mm. A PMC of the correct size is selected, adjusted if necessary to achieve a ‘snap fit’, and cemented into place. Although limited in quality, there is consistent evidence that PMCs can be effective restorations,3,4 and they are recommended as the restoration of choice for primary molars with two or more surfaces affected by dental caries.5,6 However, they are not popular with general dental practitioners (GDPs) in the United Kingdom. Data from the

© Primary Dental Care 2010;17(1):33-37

trial, only three of the GDPs had been using conventional PMCs at all and this was ‘infrequently’. None had been using them routinely. The semi-structured questionnaires revealed three main themes reflecting positively on the GDPs’ experiences with the Hall Technique: its ease of use, its high patient acceptability, and the dentists’ perceived clinical effectiveness of the technique. Thirteen of the 14 GDPs stated that they would continue to use the Hall Technique routinely and only one thought that he would not use it. Conclusion: Among a small group of GDPs with little experience or training in the use of the Hall Technique, it was perceived to be easy to use routinely, acceptable to patients and effective.

Scottish Dental Practice Board show that in 2001/2, PMCs accounted for only 0.4% of all restorations placed in the mouths of children.7 This finding has been supported by data from other areas of the United Kingdom, where surveys of GDPs’ views have also identified some of the barriers to the use of PMCs.8-11 These barriers include dentists’ perceptions that children find it difficult to cope with this technique. However, there is a paucity of evidence reporting children’s experiences of restorative care. What little literature is available seems to indicate that children prefer to avoid the use of rotary instrumentation and local analgesia where possible.12-14 The Hall Technique has been investigated as a simplified method of using PMCs to restore carious primary molars;15-17 a PMC is cemented over the tooth without LA, caries removal or any tooth preparation. Caries is sealed into the tooth, separating the lesion from the oral environment, and the child’s occlusion is allowed time to accommodate the increase in occluso-vertical dimension. This method of restoring carious

NPT Innes PhD, BDS(Hons), BSc, BMSc(Hons), MFGDP(UK), MFDS. Clinical Lecturer in Paediatric Dentistry, Dundee Dental Hospital and School, Dundee, UK. Z Marshman PhD, BDS, DDPH, MPH, MFDS, FDS(DPH). Clinical Lecturer in Dental Public Health, School of Clinical Dentistry, Sheffield, UK. RE Vendan BDS, MFDS. General Dental Practitioner, Eaglebridge Health and Wellbeing Centre, Crewe, UK.

Primary Dental Care • January 2010

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The Hall Technique: Evaluation of GDP Views

primary molars has recently been investigated using a randomised controlled trial carried out in general dental practice in the UK.17 The trial was carried out in Scotland and involved 17 GDPs in nine practices treating 132 children. The children, who had contralateral matched pairs of carious primary molars, had one tooth managed with the Hall Technique and the other with the conventional restoration that the dentist would normally have chosen to use in that clinical situation. The study showed that as well as the Hall Technique being significantly more clinically effective than the standard restorative techniques being used, it was preferred by children, their parents and the GDPs.17 Qualitative research aims to explore the feelings and perceptions of participants from their own perspectives.18 In order to investigate further the GDPs’ views on PMCs (conventional and Hall), a mixed-method evaluation consisting of qualitative interviews with the participating dentists and administration of a questionnaire of their use of PMCs was undertaken.

1. Prior to taking part in the clinical trial on the Hall Technique, did you previously fit PMCs (using local anaesthetic and a conventional preparation with a high-speed air rotor) to restore primary molars? Routinely Infrequently Never

2. Should the Hall Technique study show that this technique has a similar or better clinical outcome than the standard techniques that you have been using, would you consider its use for the restoration of primary molars in future? Routinely Infrequently Never

The aims of the study were to: • Describe GDPs’ use of conventional PMCs prior to involvement in the trial. • Describe GDPs’ use of Hall PMCs during the study and anticipated use in the future. • Investigate factors influencing the dentists’ use or non-use of the Hall Technique.

METHODS

n n n

3. Have you continued to use the Hall Technique for restoring primary molars outwith the clinical trial? Routinely When I cannot get a child to accept a conventional filling

AIMS

n n n

Infrequently No

n n n n

Figure 1 Questionnaire used with each participant following interview.

• The transcripts were read and recurring themes were identified and developed. Labels were then attached to each section of the transcripts • (indexing); the labels represented the theme with which each section was associated. • Sections of data with the same label were then brought together. Charts were created for each of the main themes using the • context and language found in the data. • The nature and content of each theme was described and discussed between the researchers. All three authors were involved in the analysis.

Number of patients recruited

A mixed-method approach was taken involving qualitative interviews and a short questionnaire. Ethics committee approval was not considered necessary for this investigation as it did not involve patient participation or patient-related data. The semi-structured interviews were carried out after the second year of the clinical trial follow-up period (but before the twoyear results had been published), and were designed to encourage the GDPs to discuss how they felt about using PMCs. Before the interviews were Patient recruitment by dentist (n=132) conducted, a topic guide was developed. 25 This included an introduction to the 21 purpose of the interview, exploration of 20 19 the dentists’ experiences of using the Hall 17 Technique and reasons for decisions to use 15 14 or not use this technique. Each dentist had one interview. The 10 9 interviews were conducted either face8 8 8 6 6 to-face (n=6) or over the telephone (n=8), 5 4 depending on the dentists’ preference. One 3 3 3 2 interviewer (NI) was responsible for carry1 0 0 ing out the interviews. The interviews were D9 D11 D7 D3 D17 D6 D1 D2* D15 D16 D10* D4 D14 D13 D5* D12 D8* Dentist ID recorded and transcribed verbatim. The data * = unavailable for interview were analysed using a framework approach Figure 2 Patient recruitment by individual GDP in the Hall Technique clinical trial. Red = GDPs who have not used the Hall Technique outwith the clinical trial or who have stated they will not be using it in future. involving the following stages:19

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NPT Innes et al

The questionnaire (Figure 1) was completed at the end of the interview and was based on questions used in a previous paper looking at GDP use of conventional PMCs.9

Table 1: Patient recruitment by individual GDP in the Hall Technique clinical trial (N=17 recruiting dentists) Dentist ID

Patients recruited (n)

RESULTS D11 Of the 18 GDPs who participated in the D9 Hall trial, 14 were contactable following the trial. All were willing to be interD17 viewed and complete a questionnaire D3 regarding their use of PMCs. Of the D7 four dentists who were unavailable for D6 interview, one had retired and three had D1 moved away. D2 All of the dentists in the study had been D15 practising for at least four years and there D16 was a wide spread of experience, from four years to 30 years in general dental practice. D10 At the time of the study, although most D4 of the practices operated mixed NHS and D14 private/capitation scheme payment systems, D13 all children were treated under the NHS D5 system. None of the dentists worked sinD12 gle-handedly. The total number of patients D8 entered into the trial by each dentist Total varied widely, with one dentist enrolling 21 patients and one dentist enrolling no patients (Table 1 and Figure 2). One dentist who treated and followed-up patients (and is therefore still included in this study) was not involved in the recruitment phase of the trial.

21 19

used them routinely (Table 2). GDPs anticipated continued use of Hall Technique PMCs

In contrast to their use of conventional PMCs, 13 GDPs (93%) thought that they would use the Hall Technique routinely, and only one GDP thought he would not continue to use the technique (Table 2).

17

GDPs use of Hall Technique PMCs outwith the clinical trial

14 9 8 8 8 6 6 4 3 3 3 2 1 0 132

The dentists were also questioned as to whether, although they were advised not to use Hall PMCs outwith the clinical trial until the results of the trial at two years were known, they had continued to use it. Nine GDPs (62%) had judged it to be useful in their clinical armamentarium in restorative children’s dentistry and had been using it routinely, three (22%) infrequently, and two (14%) had not been using it. None of the dentists felt that use of the Hall Technique should be limited only to children whom they could not get to accept conventional restorative methods (Table 2).

Qualitative analysis of interviews Analysis of the 14 semi-structured interviews revealed a range of views, both positive and negative, on the use of PMCs. The main themes were ease of use of the Hall Technique, patient Quantitative analysis of questionnaire acceptability, and effectiveness. Use of conventional PMCs prior to taking part in the trial Ease-of-use of the Hall Technique was a recurring theme Eleven GDPs (79%) reported never using conventional PMCs, from the GDPs. They were apparently surprised by how easy three (21%) used them infrequently and none of the GDPs the PMCs were to place using the Hall Technique, even though the majority had not previously fitted a PMC or been shown how to fit a Table 2: GDPs’ responses to the questionnaire (Figure 1) (n=14 dentists PMC as undergraduates. Ease-of-use participating in Hall Technique trial) was closely related to the speed with Number of GDPs giving response which PMCs could be placed using the Routinely Infrequently No/never When child Hall Technique. Placing a PMC using the unable to accept Hall Technique was felt to be as quick conventional filling as placing restorations. Occasional diffiQuestion 1. culties with the contact points between Previous use of PMCs with local teeth were mentioned. anaesthesia and tooth preparation 0 3 11 GDPs were also surprised by how Question 2. acceptable the PMCs generally were to If effective, would you use the technique in future? 13 0 1 patients. One GDP said: Question 3.

Use of the Hall Technique outwith the clinical trial?

9

3

2

0

Children are OK with them and as they are being used more often, children are happy to have them fitted.


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The Hall Technique: Evaluation of GDP Views

The Hall Technique was said to be preferred by children to the conventional restorative techniques that the GDPs were using. The lack of need for local anaesthetic was identified as an important factor in the acceptability of the Hall Technique to children. However, it was reported that some parents had concerns about the appearance of the PMCs, although children themselves did not apparently share these concerns. The third main theme was the perceived clinical effectiveness of the Hall Technique. Aspects of effectiveness included ‘longevity’, ‘lack of symptoms for patients’ and ‘good outcomes compared to conventional fillings’. It was also felt to be more cost-effective than placing restorations that would frequently fail. However, although the Hall Technique was felt to be effective, this was not always enough to encourage GDPs to use it in future. One dentist stated: I’ve no doubt that they work, the ones fitted in the trial were still there and asymptomatic.

However, the dentist went on to describe how he was ‘faced with too much caries’ and preferred to ‘nurse them [the teeth] through, placing dressings and extracting any that give problems’.

DISCUSSION In this study, a mixed-method approach was taken to investigate GDPs’ use of PMCs (conventional and Hall) and factors that may influence this. For the use of PMCs prior to the trial, the findings were similar to those reported by Threlfall et al (2005)9 where 93 GDPs were questioned regarding their use of conventional PMCs. Only 7% stated that they would use them in a clinical scenario of a case for which the British Society for Paediatric Dentistry guidelines5 indicated that a PMC would be the restoration of choice. The most commonly cited reasons for them not choosing a PMC were cost and time required to fit the PMCs, as well as cooperation of the child. In this study of the Hall Technique, none of the dentists were using conventional PMCs routinely. Only three had ever used PMCs, and for those, their use was infrequent. However, with the results of the clinical trial now published and the Hall Technique found to be effective, 13 of the 14 dentists available for discussion reported that Hall Technique PMCs would be a routine part of their future child dental care. Remuneration was mentioned by only four of the dentists and did not seem to be at the forefront of the minds of the GDPs when restoring children’s teeth. During the qualitative interviews, the Hall Technique PMCs were perceived to be more cost-effective than placing and replacing restorations. Interestingly, of the 12 dentists who were using the Hall Technique outwith the clinical trial, none limited its use only to children who had difficulty accepting conventional restorative treatment and therefore they presumably felt that it had a place in the standard restorative care of their child patients. The Care Index (the proportion of carious primary teeth in five-year-olds that are restored) is currently less than 10% in

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Scotland.20 Given the positive results from the clinical trial17 regarding the effectiveness and acceptability of the Hall Technique to GDPs, it might be anticipated, especially in the context of the low Care Index throughout the UK, that this method of managing dental caries in primary teeth will become more widely adopted. Certainly, innovations rapidly come into widespread use in general dental practice; for example, both the high-speed handpiece and composite restorative materials quickly became widely used in primary care soon after they were commercially available. However, in both of these cases, the GDPs were simply embracing new technologies. Widespread acceptance of the Hall Technique will depend on several factors. As well as dentists having to become adept at a new method of fitting PMCs, crucially, there must be adoption of the concept that there are circumstances where the best management of caries may be to seal it within primary teeth rather than to excavate it. Individual factors will mean that some GDPs will be averse to using PMCs. It is interesting to note that the one GDP who said that he would not use the Hall Technique even if it should prove to be effective and the other four dentists who had not continued to use the PMCs routinely outwith the trial were amongst the lowest patient recruiters in the clinical trial. Like most dental restorative procedures, it is likely that the Hall Technique will not suit every child, every carious primary molar in that child, or every GDP. The high success rate of study GDPs in fitting Hall crowns17 after only a single session of observation (much of which was spent on discussion of the study protocol, and training in radiography), indicates that the majority of GDPs will have little difficulty in providing the Hall Technique, should they choose to do so. The main limitation of this study was the small number of GDPs completing the questionnaire. However, the sample size was limited by the number of dentists who participated in the trial. Now that use of the Hall Technique is becoming more widespread, it would be possible to investigate further dentists’ and children’s perceptions of this restorative method for carious primary molars compared to other methods. Although it is uncommon for outcome measures relevant to clinicians and patients to be in conflict, it is very likely that there will be variations in their perceived importance to the two groups.21 For example, in a study on a dental laser conducted in primary care, the slowness of cavity preparation with the laser was not perceived by patients to be the problem that it was for the dentists.22 In future, it is therefore suggested that outcome measures for trials of restorative interventions should also involve wider patient-centred outcomes 23 and not simply how a restorative material performs physically.

CONCLUSION In conclusion, even among GDPs with little experience or training in the use of the Hall Technique, GDPs perceived it as easy to use routinely, acceptable to patients, and effective.

NPT Innes et al

REFERENCES 1. Engel RJ. Chrome steel as used in children’s dentistr y. Chron Omaha District Dent Soc. 1950;13:255-8. 2. Humphrey WP. Uses of chrome steel in children’s dentistry. Dent Surv. 1950;26:945-9. 3. Randall RC, Vrijhoef MM, Wilson NH. Efficacy of preformed metal crowns vs. amalgam restorations in primary molars: a systematic review. J Am Dent Assoc. 2000;131:337-43. 4. Innes NP, Ricketts DN, Evans DJ. Preformed metal crowns for decayed primary molar teeth. Cochrane Database Syst Rev. 2007:CD005512. 5. Fayle SA. UK National Clinical Guidelines in Paediatric Dentistry. Stainless steel preformed crowns for primary molars. Faculty of Dental Surgery, The Royal College of Surgeons of England. Int J Paediatr Dent. 1999;9:311-4. 6. Kindelan SA, Day P, Nichol R, Willmott N, Fayle SA. UK National Clinical Guidelines in Paediatric Dentistry: Stainless steel preformed crowns for primary molars. Int J Paediatr Dent. 2008;18(Suppl. 1):20-8. 7. Scottish Dental Practice Board. Annual Report 2001/2002. Edinburgh: SDPB; 2002. 8. Maggs-Rapport FL, Treasure ET, Chadwick BL. Community dental officers’ use and knowledge of restorative techniques for primary molars: an audit of two Trusts in Wales. Int J Paediatr Dent. 2000;10:133-9. 9. Threlfall AG, Pilkington L, Milsom KM, Blinkhorn AS, Tickle M. General dental practitioners’ views on the use of stainless steel crowns to restore primary molars. Br Dent J. 2005;199:453-5. 10. Roshan D, Curzon ME, Fairpo CG. Changes in dentists’ attitudes and practice in paediatric dentistry. Eur J Paediatr Dent. 2003;4:21-7.

14. van Bochove JA, van Amerongen WE. The influence of restorative treatment approaches and the use of local analgesia on children’s discomfort. Eur Arch Paediatr Dent. 2006;7:11-16. 15. Evans DJP, Southwick CAP, Foley JI, Innes NP, Pavitt SH, Hall N. The Hall Technique: a pilot trial of a novel use of preformed metal crowns for managing carious primary teeth. Accessed (20009 May 22) at: www.dundee.ac.uk/tuith/Articles/rt03.htm on 22/05/09 16. Innes NP, Stirrups DR, Evans DJ, Hall N, Leggate M. A novel technique using preformed metal crowns for managing carious primary molars in general practice: a retrospective analysis. Br Dent J. 2006;200:451-4; discussion 44. 17. Innes NP, Evans DJ, Stirrups DR. The Hall Technique; a randomized controlled clinical trial of a novel method of managing carious primary molars in general dental practice: acceptability of the technique and outcomes at 23 months. BMC Oral Health. 2007;7:18. 18. Holloway I. Basic Concepts for Qualitative Research. Oxford: Blackwell Science; 1997. 19. Ritchie J, Spencer L. Qualitative data analysis for applied policy research. In: Bryman A, Burgess RG, editors. Analyzing Qualitative Data. New York: Routledge; 1994. 20. Merrett MCW, Goold S, Jones CM, McCall DR, Macpherson LMD, Nugent ZJ, et al. National Dental Inspection Programme of Scotland. Report of the 2008 Survey of P1 Children. Edinburgh: NHS Scotland; 2008. 21. Espelid I, Cairns J, Askildsen JE, Qvist V, Gaarden T, Tveit AB. Preferences over dental restorative materials among young patients and dental professionals. Eur J Oral Sci. 2006;114:15-21. 22. Evans DJP, Matthews S, Pitts NB, Longbottom C, Nugent ZJ. A clinical evaluation of an Erbium: YAG laser for dental cavity preparation. Br Dent J. 2000 J;188:677-9. 23. Bader JD, Ismail AI. A primer on outcomes in dentistry. J Public Health Dent. 1999;59:131-5.

11. Chadwick BL, Gash C, Stewart K. Preformed metal crowns: views of a group of dental practitioners in North Wales. Prim Dent Care. 2007;14:140-4.

Correspondence: NPT Innes, Clinical Lecturer in Paediatric Dentistry, Dundee Dental Hospital & School, Park Place, Dundee DD1 4HR. E-mail: [email protected]

12. Rahimtoola S, van Amerongen E, Maher R, Groen H. Pain related to different ways of minimal intervention in the treatment of small caries lesions. ASDC J Dent Child. 2000;67:123-7, 83. 13. Schriks MC, van Amerongen WE. Atraumatic perspectives of ART: psychological and physiological aspects of treatment with and without rotary instruments. Community Dent Oral Epidemiol. 2003;31:15-20.

Adhesive Restoration of Endodontically Treated Teeth Francesco Mannocci, Giovanni Cavalli, Massimo Gagliani New Malden: Quintessence; 2008 £28; Hardcover; 130 pp; 266 illus ISBN: 978 1 85097 135 1

than the recommended six degrees. There is a short discussion comparing pros and cons of porcelain bonded to precious metal crowns versus gold coverage (p 43). However, when a few pages later (p 47) the crowning of posterior teeth is discussed, the bald statement is made that ‘metal-ceramic crowns are the restoration (sic) of choice’. This statement as a generalisation is contentious and is inconsistent with the earlier discussion, although, to be sure, that earlier discussion left the impression that these authors

This compact and extensively illustrated book (part of the

would not make more than a token effort to guide patients towards the

QuintEssentials of Dental Practice series) sets out to address a very

more conservative (of tooth tissue) option provided by partial gold

specific area—restoration of endodontically treated teeth—considering

coverage.

only restorative treatments based on adhesive technology. The authors

Generally, the book gives a pretty comprehensive consideration of

justify this in their preface on the basis that ‘the evidence supporting

the issues that might arise when restoring endodontically treated teeth.

the use of fibre posts and composite exceeds the evidence in favour of

What this reviewer found surprising, however, was that there was no

metal posts and cores’. This does not mean, however, that there is no

detailed discussion of how to restore hemisected or root-resected

mention of traditional and more conventional treatment options; where

molars.

they do have the advantage over the newer technologies, this is made quite clear. The book is aimed at the general dental practitioner; it is likely to be

For this reviewer, the guidelines given are quite prescriptive, consistent with the small size of the book. The result is a book that seems very much like a manual of instructions, with less discussion of

very helpful to any who are not already familiar with all of the adhesive

some issues than they warrant. To be fair, the authors acknowledge that

techniques described and particularly valuable, perhaps, to the relatively

this is a practical book and the scientific evidence supporting their work

inexperienced young dentist. For many among the older age group, the

is not described in detail. References are provided at the end of each

most valuable sections of the book may be those that relate to the use

chapter and practitioners considering adopting the techniques described

of fibre posts, and techniques for dealing with problems with them, such

would be well advised to follow some of them up in order to support

as their removal for re-root treatment. In general, the illustrations show

their own clinical work with a reasonable body of evidence.

represents a good example to follow, the exception to this being a molar

VERNON P HOLT BDS, FFGDP(UK), MGDS, LDS.

crown preparation (Figure 1-19(a)), which appears rather more tapered

GENERAL DENTAL PRACTITIONER, HOLT, NORFOLK, UK.

B re ook vie w

very clearly what they should do and the clinical work displayed


37