New Cochrane Systematic Reviews —Cochrane Oral Health Group

The Cochrane Oral Health Group in Issue 3, July 2006 of The CochraneLibrary published 2 systematic reviews and 3 systematic review updates.The abstracts for these reviews are below. For a full list of reviews/protocolspublished by the Cochrane Oral Health Group, please visit their website(www.ohg.cochrane.org/ ).If you are interested in contributing to the work of the Cochrane Oral HealthGroup please contact Luisa Fernandez, Cochrane Oral Health Group,MANDEC, School of Dentistry, The University of Manchester, HigherCambridge Street, Manchester, UK. Tel: +44 161 275 7819, Fax: +44 161275 7815, e-mail: luisa.fernandez@manchester.ac.uk

Systematic ReviewsADHESIVES

ADHESIVES FOR FIXED ORTHODONTIC BANDS(Cochrane Database of Systematic Reviews 2006,Issue 3. Art. No.: CD004485. DOI: 10.1002/14651858.CD004485.pub2.)Millett DT, Glenny AM, Mattick CR, Hickman J,Mandall NA.

BACKGROUND: Orthodontic treatment involves usingfixed or removable appliances (dental braces) to correct thepositions of teeth. It has been shown that the quality of treat-ment result obtained with fixed appliances is much betterthan with removable appliances. Fixed appliances are, there-fore, favored by most orthodontists for treatment. The suc-cess of a fixed orthodontic appliance depends on the metalattachments (brackets and bands) being attached securely tothe teeth so that they do not become loose during treatment.Brackets are usually attached to the front and side teeth,whereas bands (metal rings that go round the teeth) are morecommonly used on the back teeth (molars). A number of ad-hesives are available to attach bands to teeth and it is impor-tant to understand which group of adhesives bonds mostreliably, as well as reducing or preventing dental decay dur-ing the treatment period.OBJECTIVES: To evaluate the effectiveness of the adhe-sives used to attach bands to teeth during fixed appliancetreatment, in terms of (1) how often the bands come off dur-

ing treatment and (2) whether they protect the banded teethagainst decay during fixed appliance treatment.

SEARCH STRATEGY: The following electronic databaseswere searched: the Cochrane Oral Health Group’s TrialsRegister ( July 2005), the Cochrane Central Register of Con-trolled Trials (CENTRAL) (The Cochrane Library Issue 2, 2005),MEDLINE (1966 to July 2005), and EMBASE (1980 to July2005). A search of the Internet was also undertaken. Therewas no restriction with regard to publication status or languageof publication.SELECTION CRITERIA: Randomized and controlled clini-cal trials (RCTs and CCTs) (including split-mouth studies) ofadhesives used to attach orthodontic bands to molar teethwere selected. Patients with full-arch fixed orthodontic ap-pliance(s) who had bands attached to molars were included.

DATA COLLECTION AND ANALYSIS: All review au-thors were involved in study selection, validity assessment,and data extraction without blinding to the authors, adhe-sives used, or results obtained. All disagreements were re-solved by discussion.MAIN RESULTS: Five RCTs and 3 CCTs were identi-fied as meeting the review’s inclusion criteria. All includedtrials were of split-mouth design. Four trials compared chem-ically cured zinc phosphate and chemically cured glassionomer; 3 trials compared chemically cured glass ionomercement with light-cured compomer; 1 trial compared chem-ically cured glass ionomer with a chemically cured glass phos-phonate. Data analysis was often inappropriate within thestudies meeting the inclusion criteria.AUTHORS’ CONCLUSIONS: There is insufficient high-quality evidence with regard to the most effective adhesiveJ Evid Base Dent Pract 2006;6:291-3

1532-3382/$35.00� 2006 Elsevier Inc. All rights reserved.doi:10.1016/j.jebdp.2006.10.001

THE COCHRANE REVIEW

for attaching orthodontic bands to molar teeth. Further RCTsare required.

Review UpdatesTOOTHPASTES

POTASSIUM-CONTAINING TOOTHPASTES FORDENTINE HYPERSENSITIVITY(Cochrane Database of Systematic Reviews 2006,Issue 3. Art. No.: CD001476. DOI: 10.1002/14651858.CD001476.pub2.)Poulsen S, Errboe M, Lescay Mevil Y, Glenny A-M.

BACKGROUND: Dentine hypersensitivity may be definedas the pain arising from exposed dentine, typically in re-sponse to external stimuli, and which cannot be explained byany other form of dental disease. Many treatment regimenshave been recommended over the years, and in recent yearsparticular attention has been focused on toothpastes contain-ing various potassium salts.OBJECTIVES: To compare the effectiveness of potassium-containing toothpastes with control toothpastes in reducingdentine hypersensitivity.SEARCH STRATEGY: The following databases weresearched: Cochrane Oral Health Group Trials Register(searched until August 2005), CENTRAL (until August2005), EMBASE/MEDLINE, PubMed, and Web of Science(until September 2005). Bibliographies of clinical studies andreviews identified in the electronic search were checked forstudies published outside the electronically searched journals.SELECTION CRITERIA: Randomized controlled trials(RCTs) in which the effect on dentine hypersensitivity ofpotassium-containing toothpastes was tested against controltoothpastes that did not contain potassium.DATA COLLECTION AND ANALYSIS: Two of the re-view authors independently recorded the results of the in-cluded trials using a specially designed form. Sensitivity wasassessed by using thermal, tactile, air blast, and subjectivemethods.MAIN RESULTS: Six studies were included in the meta-analysis. These studies showed the statistically significant effectof potassium nitrate toothpaste on air blast and tactile sensi-tivity at 6- to 8-week follow-up, eg, the meta-analysis of air blastsensitivity showed a standardized mean difference in sensitivityscore of Y1.25 (95% confidence interval: Y1.65 to Y0.851) infavor of treatment. The subjective assessment failed to show asignificant effect at the 6- to 8-week assessment.AUTHORS’ CONCLUSIONS: The evidence generatedby this review is based on a small number of individuals.Furthermore, the effect varies with the methods applied forassessing the sensitivity.Thus, no clear evidence is availablefor the support of potassium-containing toothpastes for den-tine hypersensitivity.

PERIMPLANTITIS

INTERVENTIONS FOR REPLACING MISSINGTEETH: TREATMENT OF PERIMPLANTITIS(Cochrane Database of Systematic Reviews 2006,Issue 3. Art. No.: CD004970. DOI: 10.1002/14651858.CD004970.pub2.)Esposito M, Grusovin MG, Coulthard P,Worthington HV.

BACKGROUND: One of the key factors for the long-termsuccess of oral implants is the maintenance of healthy tissuesaround them. Bacterial plaque accumulation induces inflam-matory changes in the soft tissues surrounding oral implantsand it may lead to their progressive destruction (perimplanti-tis) and ultimately to implant failure. Different treatment strat-egies for perimplantitis have been suggested, however it isunclear which are the most effective.

OBJECTIVES: To identify themost effective interventions fortreating perimplantitis around osseointegrated dental implants.

SEARCH STRATEGY: We searched the Cochrane OralHealth Group’s Trials Register, the Cochrane Central Reg-ister of Controlled Trials (CENTRAL), MEDLINE, andEMBASE. Handsearching included several dental journals.We checked the bibliographies of the identified randomizedcontrolled trials (RCTs) and relevant review articles for stud-ies outside the handsearched journals. We wrote to authors ofall identified RCTs, to more than 55 oral implant manufac-turers, and an Internet discussion group to find unpublishedor ongoing RCTs. No language restrictions were applied. Thelast electronic search was conducted on 15 March 2006.

SELECTION CRITERIA: All RCTs of oral implants com-paring agents or interventions for treating perimplantitis arounddental implants.

DATA COLLECTION AND ANALYSIS: Screening ofeligible studies, assessment of the methodological quality ofthe trials, and data extraction were conducted in duplicateand independently by 2 review authors. We contacted theauthors for missing information. Results were expressed asrandom-effects models using weighted mean differences forcontinuous outcomes and risk ratios for dichotomous outcomeswith 95% confidence intervals (CI). Heterogeneity was to beinvestigated including both clinical and methodological factors.

MAIN RESULTS: Seven eligible trials were identified, but2 were excluded. The following procedures were tested:(1) use of local antibiotics versus ultrasonic debridement;(2) benefits of adjunctive local antibiotics to debridement;(3) different techniques of subgingival debridement; (4) laserversus manual debridement and chlorhexidine irrigation/gel;(5) systemic antibiotics plus resective surgery plus 2 differentlocal antibiotics with and without implant surface smooth-ening. Follow-up ranged from 3 months to 2 years. No meta-analysis was conducted due to different interventions testedand outcomes used. No side effects occurred in any of the trials.

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The only statistically significant differences were observed in a4-month follow-up RCT evaluating the use of adjunctive localantibiotics tomanual debridement in patients having lost at least50% of the supporting bone around the implants. There wereimproved probing attachment levels (PAL) mean differences of0.61 mm (95% CI 0.40 to 0.82), and reduced probing pocketdepths (PPD) mean differences of 0.59 mm (95% CI 0.39 to0.79) in those patients receiving adjunctive local antibiotics.This trial was judged to be at high risk of bias.AUTHORS’ CONCLUSIONS: There is no reliable evi-dence suggesting which could be the most effective inter-ventions for treating perimplantitis. This is not to say thatcurrently used interventions are not effective. However, theuse of local antibiotics in addition to manual subgingival de-bridement was associated with a 0.6-mm additional improve-ment for PAL and PPD over a 4-month period in patientsassociated with severe forms of perimplantitis. In 3 trials, thecontrol therapy, which basically consisted of a simple sub-gingival mechanical debridement, seemed to be sufficientto achieve results similar to the more complex and expensivetherapies. Smoothing of rough implant surfaces was not as-sociated with statistically significant improvements of theclinical outcomes. However, sample sizes were small, there-fore these conclusions have to be considered with great cau-tion. More well-designed RCTs are needed.

ORAL CANCER

SCREENING PROGRAMMES FOR THE EARLYDETECTION AND PREVENTION OFORAL CANCER(Cochrane Database of Systematic Reviews 2006,Issue 3. Art. No.: CD004150. DOI: 10.1002/14651858.CD004150.pub2.)Kujan O, Glenny AM, Oliver RJ, Thakker N, Sloan P.

BACKGROUND: Screening programmes for major can-cers, such as breast and cervical cancer, have effectively de-creased the mortality rate and helped to reduce the incidenceof these cancers. Although oral cancer is a global health prob-lem with increasing incidence and mortality rates, no nationalpopulation-based screening programmes for oral cancer havebeen implemented. To date there is debate on whether to em-ploy screening methods for oral cancer in the daily routinework of health providers.

OBJECTIVES: To assess the effectiveness of current screen-ing methods in decreasing oral cancer mortality.SEARCH STRATEGY: Electronic databases (MEDLINE,CANCERLIT, EMBASE, the Cochrane Central Register ofControlled Trials, 1966 to July 2005, The Cochrane Library -Issue 3, 2005), bibliographies, and handsearching of specificjournals and contact authors were used to identify publishedand unpublished data.

SELECTION CRITERIA: Randomized controlled trials(RCTs) of screening for oral cancer or precursor oral lesionsusing visual examination, toluidine blue, fluorescence imag-ing, or brush biopsy.

DATA COLLECTION AND ANALYSIS: The searchfound 112 citations and these have been reviewed. One RCTof screening strategies for oral cancer was identified as meet-ing the review’s inclusion criteria. Validity assessment, dataextraction, and statistic evaluation were undertaken by 2 in-dependent review authors.

MAIN RESULTS: One 10-year RCT has been included(n=13 clusters: 191,873 participants). Therewas no difference inthe age-standardized oral cancer mortality rates for the screenedgroup (16.4/100,000 person-years) and the control group(20.7/100,000 person-years). Interestingly, a significant 34% re-duction in mortality was recorded in high-risk subjects betweenthe intervention cohort (29.9/100,000 person-years) and thecontrol arm (45.4/100,000). However, this study has somemethodological weaknesses. Additionally, the study did notprovide any information related to costs, quality of life, or evenharms of screening from false-positive or false-negative findings.

AUTHORS’ CONCLUSIONS: Given the limitation of evi-dence (only 1 included RCT) and the potential methodologicalweakness of the included study, it is valid to say that there isinsufficient evidence to support or refute the use of a visualexamination as a method of screening for oral cancer using avisual examination in the general population. Furthermore, norobust evidence exists to suggest that other methods of screen-ing, toluidine blue, fluorescence imaging, or brush biopsy, areeither beneficial or harmful. Future high-quality studies to assessthe efficacy, effectiveness, and costs of screening are requiredfor the best use of public health resources. In addition, studiesto elucidate the natural history of oral cancer, preventionmethods, and the effectiveness of opportunistic screening inhigh-risk groups are needed. Future studies on improved treat-ment modalities for oral cancer and precancer are also required.

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Volume 6, Number 4 293Cochrane Reviews