http://adr.sagepub.com/Advances in Dental Research

http://adr.sagepub.com/content/18/3/46The online version of this article can be found at:

 DOI: 10.1177/154407370501800304

2005 18: 46ADRF.J.T. Burke

Evaluating Restorative Materials and Procedures in Dental Practice  

Published by:

http://www.sagepublications.com

On behalf of: 

International and American Associations for Dental Research

can be found at:Advances in Dental ResearchAdditional services and information for    

  http://adr.sagepub.com/cgi/alertsEmail Alerts:

 

http://adr.sagepub.com/subscriptionsSubscriptions:  

http://www.sagepub.com/journalsReprints.navReprints:  

http://www.sagepub.com/journalsPermissions.navPermissions:  

What is This? 

- Dec 1, 2005Version of Record >>

at Dicle Ãœniversitesi on November 14, 2014 For personal use only. No other uses without permission.adr.sagepub.comDownloaded from

Copyright 2005 by the International Association for Dental Research

at Dicle Ãœniversitesi on November 14, 2014 For personal use only. No other uses without permission.adr.sagepub.comDownloaded from

Copyright 2005 by the International Association for Dental Research

46

AAwide variety of research methods are appropriate togeneral dental practice, including clinical trials ofmaterials, assessment of materials and techniques,treatment trends, and assessment of behavior and

attitudes, of dentists as well as patients. This paper willdescribe the use of practice-based networks to evaluate theeffectiveness of materials and techniques in dental practice.Several practice-based research groups are presently inoperation in the UK and the USA, generally carrying outevaluations of the handling of materials, but with increasingemphasis on the clinical evaluation of restorations. Use of theDental Practice Board (of England and Wales) database hasproved to be a fruitful source of data on the long-term outcomeof restorations. Dental practice can provide the large pool ofpatients available for research. To utilize this pool of patients,dental practitioners and their support staff require training incollecting data.

Introduction

Practice-based researchIt has been suggested, by Irwin Mandel, that "the major energysource for fuelling professional change and growth isresearch", but that practitioners tend to take this for granted(Mandel, 1993). However, it has also been suggested thatresearch findings may not be published in a form that is user-friendly to practitioners, with half of respondents to a surveyof Canadian dentists preferring a commentary on a series ofabstracts or an article that translates research findings intopractical guidelines (Allison and Bedos, 2003). This may havethe potential to delay the implementation of their findings intoclinical practice. Research methodologies such as meta-analyses, systematic reviews, or randomized clinical controlledtrials are unlikely to be used by general dental practitioners,since these require knowledge of statistics and researchmethodology which are not generally within the practitioner'sgrasp. However, randomized clinical trials and retrospectiveand prospective clinical evaluations may readily be carried outin dental practice, where the patient base is likely to besubstantially greater than in dental schools or hospitals.Moreover, the patient base in dental practice representspatients of various patterns of attendance, from different walksof life, and different levels of oral hygiene and cariesexperience, whereas patients in dental hospitals may not beconsidered to represent a typical patient population, since theygenerally elect to attend such institutions because they havethe time available for treatment by students (i.e., the retired orunemployed) and may often have attended for many coursesof treatment, in which their oral hygiene will be reinforced (i.e.,their oral hygiene may be better than that in the generalpopulation).

Goodman (1993) has considered that prospective studiesare preferred to retrospective ones, controlled studies arepreferable to uncontrolled ones, randomized studies are

preferable to non-randomized ones, blind studies in whichpatients (single-blind) or patients and investigators (double-blind) do not know who received what treatment arepreferable to unblind ones, and large studies are preferable tosmall ones. However, the time required to perform the "ideal"clinical assessment may make some of these techniques lessthan ideal for general dental practice, given the rapid turnoverof new dental materials. However, a wide variety of researchmethods are appropriate to general dental practice. Theseinclude (Burke and McCord, 1993):

• clinical trials of materials,• assessment of materials and techniques,• assessment of treatment trends and treatment of disease,• assessment of behavior and attitudes (of dentists as well as

patients),• evaluation of disease incidence, and• patient satisfaction.

However, the ultimate question (for patients, dentists,administrators, and governments) must be, "How long dorestorations last?"

Effectiveness of restorative materials and techniquesThe success of a material or technique may be considered to beits performance in everyday use in a particular dentist's office.It is increasingly possible to obtain such information fromdental computer systems. Additionally, the volume of clinicalmaterial seen in general dental practice makes this an area offundamental importance in the development of newtechniques and the assessment of new materials. For clinicaltrials of materials, ideally, the population group should berepresentative of the population, and the comparison of thestudy and control groups should be double-blind, and thereshould be only a few drop-outs. Restorations should befollowed up for at least three years.

In the past, success rates of restorations have beenassessed by retrospective evaluation of patients' records, aspainstakingly described by Robinson (1971), Allan (1977),Paterson (1984), and others. This painstaking work in the pre-computer era provided valuable information on restorationlongevity, but about only one practitioner and his particulargroup of patients.

Practice-based research teamsTo carry out the above work in dental practice, practitionersrequire training in the standardization of procedures,calibration in the assessment of restorations, and training inscientific methodology. All of this is possible whenpractitioner-based research groups are teamed with theexpertise available in academic institutions, with this being awin/win situation for all. The academic institution is seen tobe carrying out relevant research, while the practitionershave an additional interest, with the potential for

EEvvaalluuaattiinngg RReessttoorraattiivvee MMaatteerriiaallssaanndd PPrroocceedduurreess iinn DDeennttaall PPrraaccttiiccee

F.J.T. Burke

Primary Dental Care Research Group, University of Birmingham School ofDentistry, St. Chad's Queensway, Birmingham B4 6NN, UK;f.j.t.burke@bham.ac.uk

Adv Dent Res 18(3):46-49, December, 2005

Key Words

Dental practice, restorative, techniques.

Presented at a symposium, "Dental Research in Primary Care",presented at the IADR Pan-European Federation meeting in Cardiff,Wales, UK, in September, 2002. Publication is supported by theProcter & Gamble Co.

at Dicle Ãœniversitesi on November 14, 2014 For personal use only. No other uses without permission.adr.sagepub.comDownloaded from

Copyright 2005 by the International Association for Dental Research

Adv Dent Res 18(3):46-49, December, 2005 Restorative Procedures in Dental Practice 47

improvement in the practice image.There is, therefore, merit in the establishment of a research

team, but it is likely that this will generally need theenthusiasm of one or more people to:

• identify interested parties,• provide basic training in research,• find suitable projects and funding, and• get the research started.

The aim of the practice-based research group shouldultimately be the identification of projects that are relevant tothem, through completion and publication.

However, the practitioners should:

• not be paid 'mercenaries',• not place restorations for money alone,• have ownership over the project, and• be equal partners with the established researchers—that is,

each group has its own role to play.

One such group is the PREP (Product Research andEvaluation by Practitioners) Panel. This group was establishedin 1993 with six general dental practitioners, and has grown toinclude 25 practitioners UK-wide. It has completed 40projects—mainly "handling" evaluations of materials andtechniques, but also, clinical evaluations of restorations ofnovel materials (Crisp and Burke, 2000; Burke et al., 2005). Thestudies are often sponsored by manufacturers, and the resultsare published.

BRIDGE (Birmingham Research in Dental GeneralPracticE) is another practice-based research group, based at theUniversity of Birmingham School of Dentistry. This group,which was established in 2000, has approximately 20 membersand holds four meetings per year at which ideas for newprojects are put forward and discussed. Four unfunded andtwo funded projects have been completed, and the group iscurrently collecting data for the project that won funding fromthe Shirley Glasstone Hughes Award at the British DentalAssociation in 2002. Among the projects discussed at recentmeetings of BRIDGE were the effect of changing to rectangularcollimation, job satisfaction in the dental profession, andfactors influencing longevity in Class V restorations and resin-retained bridges.

A West of Scotland-based practitioner research group,GRID (Glasgow Research Initiative in Dental Practice), wasfounded in 1997 by a few general dental practitioners who hadattended a lecture on research in dental practice, and whosubsequently responded to a letter inviting them to take part inpractice-based research. The group used to meet four or fivetimes per year, had approximately ten members, andcompleted several research projects (vide infra).

Some dental practitioners in Hong Kong have recentlybanded together and produced a "handling" evaluation of aresin-composite material, Esthet-X (Dentsply, Weybridge,Surrey, UK), using methodology similar to that utilized by thePREP Panel (Li et al., 2002). Other projects involving this groupare ongoing.

Perhaps the best-known group of practice-basedresearchers is the Clinical Research Associates (CRA), foundedby Gordon Christensen 30 years ago. This organization isfunded by the sales from its CRA Newsletter and carries outpractice-based evaluations of a wide range of dental materials,as well as laboratory assessments.

Most recently, groups of dental-practice-based researchershave been established in Scotland and in the Manchester area,with the aim of the latter network being to ally thepractitioners to an academic department and develop thepractitioners' research interests into research skills and,ultimately, into a research project (Kay et al., 2003).

Use of practice-based networks to evaluate theeffectiveness of materials and techniques in dental practiceThe PREP Panel operates as follows for "handling" evaluationsof materials. A manufacturer agrees to sponsor the project andco-writes a questionnaire designed to evaluate the handling ofthe material under test. The material is distributed to membersof the Panel, who use the materials as indicated and completethe questionnaire. By this means, the manufacturer receivesfeedback on the handling of his company's material by a groupof UK dental practitioners.

Some "handling" evaluations have been extended toinclude clinical assessment of restorations over several years.In such studies, the PREP Panel member places therestoration under typical general practice conditions, carriesout the baseline assessment, and arranges for the recall of thepatient for examination by a trained and calibratedindependent examiner, who examines the restorations usingmodified United States Public Health Service criteria, incombination with the panel member who placed therestoration. The mode of failure, if any, is recorded.Additionally, in some investigations, photographs are takenof a representative proportion of restorations, and a patientquestionnaire on comfort/performance of the restoration iscompleted. Both patient and practitioner are reimbursed fortheir expenses, with the time for which the practitioner'ssurgery is tied up during the patient examinations being theprincipal expense incurred by the practitioner. Since themembers of the PREP Panel are geographically diverse,budgetary constraints mean that the independent examinercan visit each locality for only one or two days. Althoughpatients must be able to attend on those specific days, thisdoes not appear to have an adverse effect on recall rates(Crisp and Burke, 2000; Burke et al., 2005).

Other groups have enlisted practitioners in clinics withoutdental schools to participate in research into restorationlongevity, without identifying the researchers under aparticular name. For example, Jan van Dijken has assessed 182large ceramic restorations in 110 patients, with 7.1% beingassessed as non-acceptable after a mean period of 4.9 years(van Dijken et al., 2001). This is an excellent example of how avariety of practicing conditions may be utilized to producemeaningful results on the success of novel restorativetechniques.

Cross-sectional studies have also been used in generaldental practice to produce useful, meaningful results, withIvar Mjör being the principal advocate of this researchmethodology (Deligeorgi et al., 2001). These studies have theadvantage, over randomized controlled clinical trials, ofproducing data which may include large numbers ofrestorations in a wide variety of patients, placed by dentistswith a wide variety of qualifications and experience. A recentexample of this type of study has examined the effects ofdifferent methods of funding restorative care in the UK onrestoration age at replacement, with restorations placed withinthe NHS being replaced at a lower age than restorationsplaced under the other funding arrangements investigated(Burke et al., 2002b). Another recent cross-sectional studyinvestigated the influence of patient factors, such as oralhygiene status and caries susceptibility, on the age at whichrestorations were replaced (Burke et al., 2001a). These twostudies were carried out by GRID, plus members of theFaculty of General Dental Practitioners (UK) who volunteeredto participate, having responded to advertising in the Facultynewsletter.

The Big Picture: use of the Dental Practice Board ofEngland and Wales (DPB) database to evaluatelongevity of restorationsThe principal function of the DPB, which is based inEastbourne, Sussex, UK, is to process claims for payment by

at Dicle Ãœniversitesi on November 14, 2014 For personal use only. No other uses without permission.adr.sagepub.comDownloaded from

Copyright 2005 by the International Association for Dental Research

48 Burke Adv Dent Res 18(3):46-49, December, 2005

dentists providing NHS dental treatment in England andWales, and to check the validity of such claims. This amountsto more than 45 million documents per annum (DentalPractice Board Annual Report 2001-2002). Work carried outby the senior statistician at the DPB has created a second,smaller database from which it is possible to "track" aproportion of the fillings placed from 1991 to the present,thereby providing longevity data and the factors influencingthem. This investigation involves the records of 82,537 adultpatients, who collectively received over half a millioncourses of treatment between 1 January 1991 and 31December 2002. This would appear to be the largest databaseever developed for research into restoration longevity, and itis anticipated that this work, the initial findings of whichhave been presented at research meetings (Lucarotti et al.,2002, 2003), will ultimately provide details of howrestoration performance is influenced by patient factors(such as age, sex, and attendance pattern), dentist factors(such as age, practicing location, country of graduation), andrestoration material (such as amalgam, composite, or glassionomer).

DiscussionWhy, in the past, did so little research originate from dentalpractice? A survey of three journals from the UK dentalliterature of 1991 showed that the percentage of publicationsrelating to clinical techniques/materials was only 22%, andthat only 9% of those articles had any general dental practiceinput (Morrow et al., 1995). Since the majority of dentaltreatment, worldwide, is carried out in dental practice, thereis therefore an imbalance between treatment output andresearch output. This is possibly not surprising, since dentalpractices are established to provide effective and efficienttreatment for patients, rather than to carry out research.Additionally, time spent on research may equate to lostincome, and involvement of practitioners in research mayproduce a conflict of interest between the their principalresponsibility to patients and the requirements of research(Wilson and Mjör, 1997).

It may be considered that dental practice should have anincreasing impact on clinical dental research. Since dentalpractice is the 'real world', a technique or material must beacceptable to practice conditions for it to be successful.However, in the past, many clinical evaluations have beencarried out on hospital-based patients, and these may not bevalid for the following reasons (Mjör and Wilson, 1997):

• The patients may not be typical of those seen in dentalpractice (they may often be dental students).

• The treatment may be carried out by well-qualifiedacademics who are less likely to be subjected to thepressures of time and cost-effectiveness that prevail indental practice.

• The clinicians may be working as part of a team which hasreceived pre-operative instructions in the handling and useof the materials under investigation.

New materials and techniques should ideally be assessedin the practice situation, since this is the predominant arena inwhich the materials and techniques will be used. It is essentialthat all new materials have a minimum of one year's clinicaldata before being released for use in general dental practice.All failures should be recorded.

Critics of practice-based research have commented on thelack of calibration of operative diagnoses and otheruncontrolled variables (Wilson and Mjör, 1997). Thesecomments may sometimes be valid and should be discussedwhen the results are reported. However, this variability is thereal-world situation. In summary, advantages of practice-basedresearch include:

• real-world/uncontrolled nature of the research,• a more realistic patient base,• different "angle" from academics, and• additional interest for the staff.

Additionally, for the practitioner who becomes involved inresearch, there is the additional benefit of involvement insomething not normally within the daily routine of dentalpractice. In the past, it was suggested that patient co-operationand attendance for recalls could be a potential problem withpractice-based research (Burke and McCord, 1993). Morerecently, however, it has been considered that patients (who arereimbursed for their involvement) are generally pleased to havebeen involved in a research project (Burke et al., 2002a).Furthermore, the dentist's involvement in a research project hasbeen thought to be a practice-builder (Mjör and Wilson, 1997).

One reported problem regarding practice-based researchhas been a lack of practitioner interest—for example, thedepressing scenario recounted by Mackie, in which only asmall proportion of the anticipated number of pairs ofrestorations were achieved (Mackie, 1998). However, a meansof avoiding this situation may be to obtain the necessaryfunding and to integrate the practitioners fully into thedevelopment of the protocol (Burke et al., 2002a). Wilson andMjör (1997) have considered that "the real challenge is toconceive and design studies which have a sound scientificbasis and which are suited to the environment in which theyare undertaken". There would appear to be evidence, from theformation of the practice-based research groups mentionedabove and the variety of projects that may be appropriate todental practice, that the importance of dental practitionerinvolvement in research is increasingly being recognized.

Finally, patients may increasingly demand information onthe potential performance of a restoration. Practice-basedresearch could go a long way toward providing suchinformation. However, as practices are increasingly becomingcomputerized, the practice computer may ultimately becomethe means of recording restoration longevity. Indeed, this willprovide patients with details of the success of a particulartechnique in their own practitioner's hands, which may well bethe "evidence" that patients want, but are often too shy to ask.

Concluding RemarksDental practice can provide the large pool of patients availablefor research. To utilize this pool of patients, dental practitionersand their support staff require training in collecting data. Theimportance of practice-based research has been emphasized byMandel, who considered that "research is not only the silentpartner in dental practice, it is the very scaffolding on whichwe build and sustain a practice" (Mandel, 1993). Theestablishment of practice-based research groups maycontribute to the realization of this ideal, although there is alsoa need to change the thinking of the dental professional, so thatthe incorporation of practice-based research philosophybecomes the norm rather than the privilege of practice-basedresearch groups.

ReferencesAllan DN (1977). A longitudinal study of dental restorations. Br

Dent J 143:87-89.Allison PJ, Bedos C (2003). Canadian dentists' view of the utility

and accessibility of dental research. J Dent Educ 67:533-541.Burke FJ, McCord JF (1993). Research in general dental practice—

problems and solutions. Br Dent J 175:396-398.Burke FJ, Wilson NH, Cheung SW, Mjör IA (2001a). Influence of

patient factors on age of restorations at failure and reasons fortheir placement and replacement. J Dent 29:317-324.

Burke FJ, Crisp RJ, Bell TJ, Healy A, Mark B, McBirnie R, et al.

at Dicle Ãœniversitesi on November 14, 2014 For personal use only. No other uses without permission.adr.sagepub.comDownloaded from

Copyright 2005 by the International Association for Dental Research

Adv Dent Res 18(3):46-49, December, 2005 Restorative Procedures in Dental Practice 49

(2001b). One year retrospective clinical evaluation of hybridcomposite restorations placed in United Kingdom generalpractices. Quintessence Int 32:293-298.

Burke FJ, Crisp RJ, McCord JF (2002a). Research in dental practice:a 'SWOT' analysis. Dent Update 29:80-84, 86-87.

Burke FJ, Wilson NH, Cheung SW, Mjör IA (2002b). Influence ofthe method of funding on the age of failed restorations ingeneral dental practice in the UK. Br Dent J 192:699-702.

Burke FJ, Crisp RJ, Balkenhol M, Bell TJ, Lamb JJ, McDermott K, etal. (2005). Two-year evaluation of restorations of a packablecomposite placed in UK general dental practices. Br Dent J199:293-296.

Crisp RJ, Burke FJT (2000). One-year clinical evaluation ofcompomer restorations placed in general practice. QuintessenceInt 31:181-186.

Deligeorgi V, Mjör IA, Wilson NH (2001). An overview of reasonsfor the placement and replacement of restorations. Prim DentCare 8:5-11.

Dental Practice Board Annual Report 2001-2002. Eastbourne:Dental Practice Board, 2002. http://www.dpb.nhs.uk.

Goodman C (1993). Literature searching and evidenceinterpretation for assessing health care practices. Stockholm:The Swedish Council on Technology Assessment in HealthCare.

Kay EJ, Ward N, Locker D (2003). A general dental practiceresearch network-philosophy, activities and participant views.Br Dent J 194:545-549.

Li RW, Pang AW, Sun F (2002). Research in general dental practice:evaluation of the clinical use of a new composite system bygeneral dental practitioners. Prim Dent Care 9:57-61.

Lucarotti PSK, Holder RL, Burke FJT (2002). One-year re-treatmentrates of teeth with directly placed restorations (abstract). J DentRes 81(Spec Iss A):334.

Lucarotti PSK, Holder RL, Burke FJT (2003). Patient age and re-interventions within one year following directly placedrestorations (abstract). J Dent Res 82(Spec Iss C):584.

Mackie IC (1998). Evidence-based research in the primary dentalcare setting. Br Dent J 184:6.

Mandel ID (1993). Clinical research-the silent partner in dentalpractice. Quintessence Int 24:453-463.

Mjör IA, Wilson NH (1997). General dental practice: the missinglink in dental research. J Dent Res 76:820-821.

Morrow L, Burke FJ, McCord JF (1995). Trends in publications onclinical techniques/materials, 1971-1991. Int Dent J 45:163-165.

Paterson N (1984). The longevity of restorations. A study of 200regular attenders in a general dental practice. Br Dent J 157:23-25.

Robinson AD (1971). The life of a filling. Br Dent J 130:206-208.van Dijken JW, Hasselrot L, Ormin A, Olofsson AL (2001).

Restorations with extensive dentin/enamel-bonded ceramiccoverage. A 5-year follow-up. Eur J Oral Sci 109:222-229.

Wilson NH, Mjör IA (1997). Practice-based research: importance,challenges and prospects. A personal view. Prim Dent Care4:5-6.

at Dicle Ãœniversitesi on November 14, 2014 For personal use only. No other uses without permission.adr.sagepub.comDownloaded from

Copyright 2005 by the International Association for Dental Research