High certainty evidence is stable and trustworthy, whereas evidence of moderate or lower certainty may be equally prone to being unstable.

OBJECTIVES: To assess to what extent the overall quality of evidence indicates changes to observe intervention effect estimates when new data become available. METHODS: We conducted a meta-epidemiological study. We obtained evidence from meta-analyses of randomized trials of Cochrane reviews addressing the same health-care question that was updated with inclusion of additional data between January 2016 and May 2021. We extracted the reported effect estimates with 95% confidence intervals (CIs) from meta-analyses and corresponding GRADE (Grading of Recommendations Assessment, Development, and Evaluation) assessments of any intervention comparison for the primary outcome in the first and the last updated review version. We considered the reported overall quality (certainty) of evidence (CoE) and specific evidence limitations (no, serious or very serious for risk of bias, imprecision, inconsistency, and/or indirectness). We assessed the change in pooled effect estimates between the original and updated evidence using the ratio of odds ratio (ROR), absolute ratio of odds ratio (aROR), ratio of standard errors (RoSE), direction of effects, and level of statistical significance. RESULTS: High CoE without limitations characterized 19.3% (n = 29) out of 150 included original Cochrane reviews. The update with additional data did not systematically change the effect estimates (mean ROR 1.00; 95% CI 0.99-1.02), which deviated 1.06-fold from the older estimates (median aROR; interquartile range [IQR]: 1.01-1.15), gained precision (median RoSE 0.87; IQR 0.76-1.00), and maintained the same direction with the same level of statistical significance in 93% (27 of 29) of cases. Lower CoE with limitations characterized 121 original reviews and graded as moderate CoE in 30.0% (45 of 150), low CoE in 32.0% (48 of 150), and very low CoE in 18.7% (28 of 150) reviews. Their update had larger absolute deviations (median aROR 1.12 to 1.33) and larger gains in precision (median RoSE 0.78-0.86) without clear and consistent differences between these categories of CoE. Changes in effect direction or statistical significance were also more common in the lower quality evidence, again with a similar extent across categories (without change in 75.6%, 64.6%, and 75.0% for moderate, low, very low CoE). As limitations increased, effect estimates deviated more (aROR 1.05 with zero, 1.11 with one, 1.25 with two, 1.24 with three limitations) and changes in direction or significance became more frequent (93.2% stable with no limitations, 74.5% with one, 68.2% with two, and 61.5% with three limitations). CONCLUSION: High-quality evidence without methodological deficiencies is trustworthy and stable, providing reliable intervention effect estimates when updated with new data. Evidence of moderate and lower quality may be equally prone to being unstable and cannot indicate if available effect estimates are true, exaggerated, or underestimated.

Risk of bias and methodological critical appraisal in systematic reviews of non- and micro-invasive caries management for primary and permanent teeth.

INTRODUCTION: Paediatric dentistry should rely on evidence-based clinical decisions supported by high-quality, unbiased systematic reviews (SRs). Therefore, the purpose of this study was to systematically evaluate the methodological quality and risk of bias of SRs focused on non- and micro-invasive treatment for caries lesions in primary and permanent teeth. METHODS: A comprehensive search was conducted in multiple databases, including MEDLINE/PubMed, Scopus, Web of Science, EMBASE, Epistemonikos, and ProQuest, up to March 2023 to identify relevant systematic reviews (SRs) focused on non- and micro-invasive caries treatment. Two independent reviewers extracted data from the included SRs and assessed the methodological quality and risk of bias using the AMSTAR 2 and ROBIS tools, respectively. RESULTS: A total of 39 SRs were included in the analysis. Among these, 27 SRs (69.2%) were assessed as having critically low methodological quality, 11 SRs (28.2%) were considered to have low methodological quality and only one SR was rated as high-quality. The primary concern identified was the absence of protocol registration before the commencing the study, observed in 33 SR when using the AMSTAR 2 tool. According to the ROBIS tool, 21 studies (53.8%) were categorised as low risk of bias, 10 (25.6%) as high risk and eight (20.5%) as unclear risk of bias. CONCLUSION: Our analysis revealed that SRs focused on non- and micro-invasive treatment for caries in children and adolescents had critically low methodological quality according to the AMSTAR 2 tool but demonstrated a low risk of bias based on the ROBIS tool. These findings highlight the importance of emphasizing prospective protocol registration, clear reporting of statistical analyses, and addressing potential bias implications within this topic. By addressing these issues, we can enhance the quality of SRs and ensure that clinical decisions rely on unbiased and trustworthy evidence. Registry DOI: 10.17605/OSF.IO/AR4MS.

Health professionals' recommendations on the use of fluoride varnish for caries prevention in preschool children.

BACKGROUND: Fluoride varnish (FV) is widely recommended for caries prevention in preschool children, despite its anticaries benefits being uncertain and modest. Dentists often report using clinical practice guidelines (CPGs) as a source of scientific information. AIM: To identify and analyze recommendations for clinical practice on the use of FV for caries prevention in preschool children and to assess the methodological quality of the CPG on this topic. DESIGN: Two researchers independently used 12 search strategies and searched the first five pages of Google Search™ and three guideline databases for recommendations freely available to health professionals on the use of FV for caries prevention in preschoolers. Then, they retrieved and recorded recommendations that met the eligibility criteria and extracted the data. A third researcher resolved disagreements. Each included CPG was appraised using the AGREE II instrument. RESULTS: Twenty-nine documents were included. Recommendations varied according to age, patients' caries risk, and application frequency. Of the six CPGs, only one scored above 70% in the AGREE II overall assessment. CONCLUSION: Recommendations on the use of FV lacked scientific evidence, and CPGs were of poor quality. Application of FV is widely recommended despite recent evidence showing an uncertain, modest, and possibly not clinically relevant anticaries benefit. Dentists should be aware that it is necessary to critically appraise CPGs since they may be of poor quality.

Economic evaluation of fluoride varnish application in preschoolers: A systematic review.

BACKGROUND: Fluoride varnish (FV) is a convenient way of professionally applying fluoride in preschoolers. However, its modest anticaries effect highlights the need for economic evaluations. AIM: To assess economic evaluations reporting applications of FV to reduce caries incidence in preschoolers. DESIGN: We included full economic evaluations with preschool participants, in which the intervention was FV and the outcome was related to dentin caries. We searched in CENTRAL; MEDLINE via PubMed; WEB OF SCIENCE; EMBASE; SCOPUS; LILACS; BBO; and BVS Economia em saúde, OpenGrey, and EconoLit. Clinical trial registers, thesis and dissertations, and meeting abstracts were hand searched, as well as 11 dental journals. Risk of bias in the included studies was assessed using the Philips' and Drummond's (full and simplified) tools. RESULTS: Titles and abstracts of 2871 articles were evaluated, and 200 were read in full. Eight cost-effectiveness studies were included: five modeling and three within-trial evaluations. None of the studies gave sufficient information to allow a thorough assessment using the bias tools. We did not combine the results of the studies due to the great heterogeneity among them. Four studies reported that FV in preschool children was a cost-effective measure, but in one of these studies, sealants and fluoride toothpaste were more cost-effective measures than the varnish, and three studies used limited data that compromised the generalizability of their results. The other four studies showed a large increase in costs due to the application of varnish and/or low cost-effectiveness. CONCLUSION: We did not find convincing overall evidence that applying FV in preschoolers is an anticaries cost-effective measure. The protocol of this systematic review is available at Open Science Framework (https://osf.io/xw5va/).

Efficacy and safety of hemodialysis strategies for pregnant women with chronic kidney disease: Systematic review.

Pregnancy in chronic kidney disease (CKD) women is relatively rare, and the less risky choice of hemodialysis is unknown. The objective of this systematic review was to identify, systematically evaluate and summarize the available evidence on the efficacy and safety of hemodialysis strategies for pregnant CKD women. Sensitive search strategies were applied to six databases without data or language restrictions. Comparative (randomized and non-randomized) studies were prioritized. Two reviewers independently selected, extracted, and critically evaluated data from studies. The risk of bias assessment was performed using the ROBINS-I tool, considering the study design (non-randomized comparative observational studies). The certainty of the evidence was assessed using the GRADE approach. From 7210 references identified, six retrospective cohort studies were included (576 women). The effects of intensive hemodialysis (over 20 h/week) are uncertain for maternal and neonatal mortality (Peto odds ratio [OR] 0.85; 95% confidence interval [95% CI] 0.26-2.80), miscarriage (Peto OR 0, 38; 95% CI 0.12-1.23), stillbirths (Peto OR 0, 56; 95% CI 0.13-2.31), preterm birth (Peto OR 0.87; 95% CI 0.33-2.28), low birth weight (Peto OR 0.71; 95% CI 0.20-2.50) and congenital anomalies rates. The certainty of the evidence was very low due to studies methodological limitations and effect estimates imprecision. The uncertainty about intensive versus conventional hemodialysis effects for pregnant women with CKD and the imprecision in the estimated effects precludes any recommendation. The strategy choice must consider treatment availability, costs, and maternal social aspects until future studies provide more reliable evidence. PROSPERO CRD42021259237.

Does the use of fiber posts increase the fracture resistance of simulated immature teeth? A systematic review.

This systematic review aimed to assess if the use of fiber posts reinforces weakened immature teeth. A systematic review was conducted of laboratory studies that evaluated the fracture resistance of simulated immature teeth restored with fiber posts compared to teeth restored exclusively with resin. An electronic search was performed using the following databases: PubMed/MEDLINE, Web of Science, Scopus and LILACS, BBO, and grey literature. Two independent researchers screened the titles and abstracts of the retrieved studies for relevance to the research question. Subsequently, the full texts of potentially relevant studies were screened based on the exclusion criteria. Ten out of 1792 unique records were included in this systematic review. Risk of bias was assessed using an adapted tool based on the Cochrane risk of bias tool. The laboratory studies included in this systematic review were performed on both human and bovine teeth. Eight studies concluded that fiber posts reinforce the structure of weakened roots, and two studies reported that fiber posts did not strengthen the radicular structure compared to teeth exclusively restored with resin composite. The highly heterogeneous data made it challenging to synthesize the results into a summary estimate, and thus no meta-analysis was undertaken. A summary effect could not be estimated without a meta-analysis. Although the laboratory literature suggests that fiber posts reinforce the structure of immature teeth, the results should be interpreted with caution, as most of the studies had an unclear or high risk of bias.

High quality (certainty) evidence changes less often than low-quality evidence, but the magnitude of effect size does not systematically differ between studies with low versus high-quality evidence.

RATIONALE, AIMS, AND OBJECTIVES: It is generally believed that evidence from low quality of evidence generate inaccurate estimates about treatment effects more often than evidence from high (certainty) quality evidence (CoE). As a result, we would expect that (a) estimates of effects of health interventions initially based on high CoE change less frequently than the effects estimated by lower CoE (b) the estimates of magnitude of effect size differ between high and low CoE. Empirical assessment of these foundational principles of evidence-based medicine has been lacking. METHODS: We reviewed the Cochrane Database of Systematic Reviews from January 2016 through May 2021 for pairs of original and updated reviews for change in CoE assessments based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method. We assessed the difference in effect sizes between the original versus updated reviews as a function of change in CoE, which we report as a ratio of odds ratio (ROR). We compared ROR generated in the studies in which CoE changed from very low/low (VL/L) to moderate/high (M/H) versus M/H to VL/L. Heterogeneity and inconsistency were assessed using the tau and I2 statistic. We also assessed the change in precision of effect estimates (by calculating the ratio of standard errors) (seR), and the absolute deviation in estimates of treatment effects (aROR). RESULTS: Four hundred and nineteen pairs of reviews were included of which 414 (207 × 2) informed the CoE appraisal and 384 (192 × 2) the assessment of effect size. We found that CoE originally appraised as VL/L had 2.1 [95% confidence interval (CI): 1.19-4.12; p = 0.0091] times higher odds to be changed in the future studies than M/H CoE. However, the effect size was not different (p = 1) when CoE changed from VL/L → M/H [ROR = 1.02 (95% CI: 0.74-1.39)] compared with M/H → VL/L (ROR = 1.02 [95% CI: 0.44-2.37]). Similar overlap in aROR between the VL/L → M/H versus M/H → VL/L subgroups was observed [median (IQR): 1.12 (1.07-1.57) vs. 1.21 (1.12-2.43)]. We observed large inconsistency across ROR estimates (I2 = 99%). There was larger imprecision in treatment effects when CoE changed from VL/L → M/H (seR = 1.46) than when it changed from M/H → VL/L (seR = 0.72). CONCLUSIONS: We found that low-quality evidence changes more often than high CoE. However, the effect size did not systematically differ between the studies with low versus high CoE. The finding that the effect size did not differ between low and high CoE indicate urgent need to refine current EBM critical appraisal methods.

Prevalence of dental anxiety in children and adolescents globally: A systematic review with meta-analyses.

BACKGROUND: Dental anxiety (DA) negatively impacts oral health-related quality of life, and patients with DA usually require more dental treatment time. AIM: To describe the global prevalence of DA in children and adolescents and to examine the influence of individual factors (age, sex, and caries experience) and variables related to DA measurement on pooled prevalence. DESIGN: Systematic review with meta-analyses of observational studies published between 1985 and 2020 (PROSPERO CRD42014013879). RESULTS: Searches yielded 1207 unique records; 224 full-text articles were screened, and 50 studies were used in the qualitative and quantitative synthesis. No study was considered as having high methodological quality according to 'The Joanna Briggs Institute assessment tool'. Overall pooled DA prevalence was 23.9% (95% CI 20.4, 27.3). Pooled prevalence in preschoolers, schoolchildren, and adolescents was as follows: 36.5% (95% CI 23.8, 49.2), 25.8% (95% CI 19.5, 32.1), and 13.3% (95% CI 9.5, 17.0), respectively. DA was significantly more prevalent in preschool children (one study) and schoolchildren (two studies) with caries experience and in female adolescents (one study). The scale used for DA assessment was shown to influence pooled prevalence in preschoolers and adolescents. CONCLUSION: DA is a frequent problem in 3- to 18-year-olds worldwide, more prevalent in schoolchildren and preschool children than in adolescents.

Fluoride Varnish and Dental Caries in Preschoolers: A Systematic Review and Meta-Analysis.

The aim of this study was to assess the effectiveness of fluoride varnish (FV) in reducing dentine caries at the patient, tooth, and surface levels as well as caries-related hospitalizations in preschoolers. We performed a systematic review of clinical trials of FV, alone or associated with an oral health program, compared with placebo, usual care, or no intervention. Bibliographical search included electronic searches of seven databases, registers of ongoing trials, and meeting abstracts, as well as hand searching. We performed random-effects meta-analyses and calculated confidence and prediction intervals. The search yielded 2,441 records; 20 trials were included in the review and 17 in at least one meta-analysis. Only one study had low risk of bias in all domains. We found no study reporting on caries-related hospitalizations. At the individual level, the pooled relative risk was 0.88 (95% confidence interval [CI] 0.81, 0.95); this means that in a population of preschool children with 50% caries incidence, we need to apply fluoride varnish in 17 children to avoid new caries in one child. At the tooth level, the pooled weighted mean difference was -0.30 (95% CI -0.69, 0.09) and at the surface level -0.77 (95% CI -1.23, -0.31). Considering the prediction intervals, none of the pooled estimates were statistically significant. We conclude that FV showed a modest and uncertain anticaries effect in preschoolers. Cost-effectiveness analyses are needed to assess whether FV should be adopted or abandoned by dental services.

Prevalence of self-reported gingival bleeding in a representative sample of the Brazilian adolescent population.

AIM: To estimate the prevalence of self-reported gingival bleeding in a representative sample of 12- to 17-year-old Brazilian adolescents. MATERIALS AND METHODS: Sociodemographic and oral health information were obtained through a self-administered questionnaire of the Study of Cardiovascular Risk Factors in Adolescents. The adolescents answered "yes" or "no" to the question "Do your gums bleed?" RESULTS: 74,589 of the 102,327 eligible adolescents answered the questionnaire and 18.4% (95% CI 17.5-19.3) reported having bleeding gums. The prevalence of self-reported gingival bleeding varied as following: 21.4% (95% CI 20.3-22.6) in girls and 15.3% (95% CI 14.3-16.4) in boys; 20.5% (95% CI 19.2-21.8) in older and 17.5% (95% CI 16.4-18.6) in younger adolescents; 20.6% (95% CI 18.5-22.9) in Black people and 17.1% (95% CI 16.1-18.1) in White people. Regarding mother's level of education, the prevalences were 18.1% (95% CI 16.2-20.3), 17.6% (95% CI 16.4-18.9) and 19.3% (95% CI 17.9-20.9) for high, middle and low levels, respectively. For socioeconomic status, the equivalent figures were 16.4% (95% CI 14.3-18.7), 18.4% (95% CI 17.5-19.4) and 23.0% (95% CI 17.3-29.9). CONCLUSION: Nearly one in five Brazilian adolescents reported having gingival bleeding, which might not be a serious condition, but reflect the disease and the adolescents' perception of oral health status.

A systematic review of the effects of supervised toothbrushing on caries incidence in children and adolescents.

BACKGROUND: The anticaries effect of supervised toothbrushing, irrespective of the effect of fluoride toothpaste, has not been clearly determined yet. AIM: To assess the effects of supervised toothbrushing on caries incidence in children and adolescents. DESIGN: A systematic review of controlled trials was performed (CRD42014013879). Electronic and hand searches retrieved 2046 records, 112 of which were read in full and independently assessed by two reviewers, who collected data regarding characteristics of participants, interventions, outcomes, length of follow-up and risk of bias. RESULTS: Four trials were included and none of them had low risk of bias. They were all carried out in schools, but there was great variation regarding children's age, fluoride content of the toothpaste, baseline caries levels and the way caries incidence was reported. Among the four trials, two found statistically significant differences favouring supervised toothbrushing, but information about the magnitude and/or the precision of the effect estimate was lacking and in one trial clustering effect was not taken into consideration. No meta-analysis was performed due to the clinical heterogeneity among the included studies and differences in the reporting of data. CONCLUSIONS: There is no conclusive evidence regarding the effectiveness of supervised toothbrushing on caries incidence.

Semiannual Fluoride Applications in Low-Risk Toddlers May Not Be More Effective Than Toothbrushing Instruction and Dietary Counseling in Controlling Dental Caries.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Effectiveness of early preventive intervention with semiannual fluoride varnish application in toddlers living in high-risk areas: A stratified cluster-randomized controlled trial. Anderson M, Dahlöf G, Twetman S, Jansson L, Bergenlid AC, Grindefjord M. Caries Res 2016;50(1):17-23. SOURCE OF FUNDING: The study was commissioned and supported by Stockholm County Council and Karolinska Institutet. TYPE OF STUDY/DESIGN: Non-blinded, cluster-randomized controlled field trial with two parallel arms.

Are fluoride releasing dental materials clinically effective on caries control?

OBJECTIVES: (1) To describe caries lesions development and the role of fluoride in controlling disease progression; (2) to evaluate whether the use of fluoride-releasing pit and fissure sealants, bonding orthodontic agents and restorative materials, in comparison to a non-fluoride releasing material, reduces caries incidence in children or adults, and (3) to discuss how the anti-caries properties of these materials have been evaluated in vitro and in situ. METHODS: The search was performed on the Cochrane Database of Systematic Reviews and on Medline via Pubmed. RESULTS: Caries is a biofilm-sugar dependent disease and as such it provokes progressive destruction of mineral structure of any dental surface - intact, sealed or restored - where biofilm remains accumulated and is regularly exposed to sugar. The mechanism of action of fluoride released from dental materials on caries is similar to that of fluoride found in dentifrices or other vehicles of fluoride delivery. Fluoride-releasing materials are unable to interfere with the formation of biofilm on dental surfaces adjacent to them or to inhibit acid production by dental biofilms. However, the fluoride released slows down the progression of caries lesions in tooth surfaces adjacent to dental materials. This effect has been clearly shown by in vitro and in situ studies but not in randomized clinical trials. SIGNIFICANCE: The anti-caries effect of fluoride releasing materials is still not based on clinical evidence, and, in addition, it can be overwhelmed by fluoride delivered from dentifrices.

Fluoride Varnish Applications in Preschoolers and Dental Fluorosis in Permanent Incisors: Results of a Nested-cohort Study Within a Clinical Trial.

PURPOSE: To compare the prevalence and severity of fluorosis in the permanent maxillary incisors of children who had participated in a two-year randomized placebo-controlled clinical trial on fluoride varnish application in the primary dentition and to assess children's esthetic perception of their teeth. METHODS: Parents of 200 one- to four-year-old children who had received biannual applications of fluoride or placebo varnish were contacted four years after the end of the trial. Two calibrated examiners assessed dental fluorosis using the Thylstrup and Fejerskov index (TF) and interviewed the children regarding their perceptions of teeth appearance. RESULTS: Fluorosis (TF equals at least one) and esthetically objectionable fluorosis (TF equals at least three) were observed in 38 (30.9 percent) and eight (6.5 percent) children, respectively. There was no statistically significant difference in fluorosis prevalence between children who had received fluoride or placebo varnish. Children's responses regarding the esthetic perceptions of their teeth showed no statistically significant difference between children with and without fluorosis. CONCLUSIONS: Fluoride varnish applications in preschoolers were not associated with any level of fluorosis in their permanent maxillary incisors. The fluorosis found in this study did not influence the children's esthetic perception of their teeth.

Children's Toothbrushing Practices Recommended on the Internet by Pediatric Dentistry Associations.

PURPOSE: The purpose of this study was to describe online recommendations by North and South American National Associations of Pediatric Dentistry (NAPD), intended for laypersons, concerning children's toothbrushing practices. METHODS: In February 2015, the International Association of Pediatric Dentistry (IAPD) website and the Latin American Association of Pediatric Dentistry (ALOP) Facebook webpage were searched to identify which countries had NAPD. Attempts were made to obtain the electronic addresses of ALOP national member societies, and Google and Facebook were used to identify NAPD not found using the previous strategies. RESULTS: Of the 35 countries in North and South America, 19 had NAPD that were shown on the Internet, and 11 of them provided data for the study. All NAPD gave advice on fluoride concentrations in toothpaste and when to start toothbrushing; most made recommendations on the amount of toothpaste, toothbrushing frequency, and when to brush, and a few gave advice on toothbrushing supervision and rinsing after toothbrushing. There was no consensus on most of the recommendations that were evaluated. CONCLUSIONS: Only a few National Associations of Pediatric Dentistry from the Americas provide online information for parents and laypersons concerning children's toothbrushing practices. Of the information provided, some are either controversial, outdated or lack scientific evidence.

A systematic review and meta-analysis of the effects of fluoride toothpastes on the prevention of dental caries in the primary dentition of preschool children.

OBJECTIVES: To assess the effects of fluoride (F) toothpastes on the prevention of dental caries in the primary dentition of preschool children. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A search for randomized or quasi-randomized clinical trials was carried out, without idiom restraints, in six electronic databases, registers of ongoing trials, meeting abstracts, dentistry journals and reference lists of potentially eligible studies. The search yielded 1932 records and 159 full-text articles were independently read by two examiners. Data regarding characteristics of participants, interventions, outcomes, length of follow-up and potential of bias were independently extracted by two examiners on the basis of predetermined criteria. Any disagreement was solved by consensus after consulting a third examiner. Pooled prevented fractions (PF) and relative risks (RR) were estimated separately for studies testing low F toothpastes (<600 ppm) and those testing standard F toothpastes (1000­1500 ppm). RESULTS: Eight clinical trials fulfilled the inclusion criteria and most of them compared F toothpastes associated with oral health education against no intervention. When standard F toothpastes were compared to placebo or no intervention, significant caries reduction at surface (PF = 31%; 95% CI 18­43; 2644 participants in five studies), tooth (PF = 16%; 95% CI 8­25; 2555 participants in one study) and individual (RR = 0.86; 95% CI 0.81­0.93; 2806 participants in two studies) level were observed. Low F toothpastes were effective only at surface level (PF = 40%; 95% CI 5­75; 561 participants in two studies). CONCLUSION: Standard F toothpastes are effective in reducing dental caries in the primary teeth of preschool children and thus their use should be recommended to this age group.

Inconsistencies in recommendations on oral hygiene practices for children by professional dental and paediatric organisations in ten countries.

BACKGROUND: Some of the basic dental health practices that are recommended to the public by professionals are not evidence based. Incorrect oral health messages may adversely affect children's oral health behaviours. AIM: To identify and list the recommendations concerning children's oral hygiene practices provided by dental and paediatric organisations, and to assess how these recommendations relate to the scientific evidence currently available. DESIGN: Cross-sectional. The authors contacted professional organisations in ten countries requesting items (brochures, leaflets or folders) containing messages on children's oral hygiene practices. They then listed these recommendations and assessed how they related to scientific evidence obtained from systematic reviews available at PubMed and the Cochrane Library. RESULTS: Fifty-two of 59 (88%) organisations responded to our request and 24 dental health education materials were submitted to the authors. They mentioned recommendations on oral hygiene practices for children, such as toothbrushing frequency, supervision and technique; when to start and how long toothbrushing should last; toothbrush design and replacement; flossing; gums/teeth wiping; tongue cleaning; type and amount of toothpaste and advice on toothpaste ingestion. The search at PubMed and the Cochrane Library resulted in 11 systematic reviews addressing these topics. CONCLUSIONS: Several oral hygiene messages delivered by professional organisations showed inconsistencies and lacked scientific support.