Assessment of interproximal enamel reduction planned by the digital set-up of a customized lingual orthodontic appliance: A comparison cohort study.

Objectives: Interproximal enamel reduction (IER), commonly known as stripping, is a frequently used technique in orthodontic treatment to address issues related to arch length discrepancies and tooth size discrepancies (TSD). The use of digital set-up allows for precise prediction of the amount of IER required. TSD occurs when the sizes of maxillary and mandibular teeth are not in proportion to each other. This study aims to evaluate and compare the suggested IER values generated by the digital set-up of a customized lingual orthodontic appliance in both upper and lower arches, across sextants, and among different teeth concerning TSD. Materials and methods: We analyzed suggested IER values from 809 cases. The statistical analysis was divided into two parts: part 1 focused on the number of stripped surfaces, and part 2 assessed the quantity of enamel removed. Comparisons were made between upper and lower arches, sextants, and teeth using the Friedman test, followed by pairwise Wilcoxon tests with Bonferroni correction. Results: The study found that mandibular and frontal stripping were more frequently suggested than maxillary and posterior stripping. Lower canines were the teeth most commonly recommended for stripping, followed by upper incisors. Conclusion: Within the scope and limits of this cohort study, we conclude that, in general, more IER is required in the mandible as compared to the maxilla. Particularly in the anterior sextants, IER might be necessary to achieve optimal alignment and occlusion.

Detection of Erosive Changes on Smooth Surfaces with and without Orthodontic Brackets Using an Intraoral Scanner-An In Vitro Study.

BACKGROUND: Consumption of acidic beverages favours development of erosions. Modern diagnostic methods are required to detect erosions at an early stage. This study aimed to evaluate the suitability of an intraoral scanner (IOS) for detection of erosive changes on smooth surfaces adjacent to orthodontic brackets. METHODS: Orthodontic metal brackets were attached to the buccal surfaces of 58 extracted permanent human teeth. Teeth were randomly divided into groups: A = 6% citric acid, B = Coca-Cola, C = Redbull, D = Powerade, E = Control, no acid exposure. Teeth were exposed to acid in three erosion cycles, followed by rinsing and brushing. Scans of teeth were performed at baseline and after each erosion cycle and enamel loss was measured. Quantitative light-induced fluorescence (QLF) measurements were performed as reference standard. RESULTS: Significant substance loss was measured in all acid groups after the second and third erosion cycle (p < 0.0001). Correlation between scans and QLF were significant (p = 0.001). CONCLUSIONS: With IOS, it was possible to detect and quantify enamel erosion at smooth surfaces with and without orthodontic brackets after a short exposure time. Considering the limitations of in vitro results, the use of IOS can be a promising digital tool to detect and monitor erosive enamel changes during fixed orthodontic treatment.

A Parental Behavior Scale in Pediatric Dentistry: The Development of an Observational Scale.

Children's treatment means a triangular relationship between the child, practitioner, and parent, with specific interactions influencing the procedure. The objective was to create and validate a hetero-rating scale of parental behavior and verify the correlation between child and parental behavior during pediatric dentistry sessions. Treatment sessions were recorded and evaluated, including 60 children representing three age groups. Two raters interpreted the resulting video clips using the modified Venham scale for children and the new hetero-rating scale for parents. They analyzed the videos twice and attributed scores at different time points of the appointment. The correlation between parental behavior upon entrance and the children's behavioral at the dental office in the treatment stage was significantly positive in both raters (Kendall Tau: 0.20-0.30). Furthermore, a panel of 20 dental practitioners scored a randomized selection of five recordings per age group. The level of agreement between the two experts was higher than that between the 20 clinicians. Venham types of scale involving multiple aspects can be used in research, but their application in dental practice requires further development. The link between parental anxiety and child anxiety is confirmed, but further research is required to incorporate specific aspects of treatment and parental behavior.

Ability of a Blue Hemoglobin-Based Liquid as a Novel Technology to Stain Initial Enamel Demineralization: A Proof-of-Concept in vitro Study.

During orthodontic treatment, enamel demineralization can occur. Its early detection is the basis for efficient preventive measures to arrest or remineralize lesions. In the present study, the application of a novel blue hemoglobin-based liquid (BlueCheck) was evaluated as proof of concept for detection of artificially demineralized smooth surfaces. 60 samples from extracted human posterior teeth were randomly assigned to four groups (15 per group). In 30 of these samples (groups A and B), superficial enamel was removed to create a ground surface. On the surface of other 30 samples (group C and D), orthodontic metal brackets were bonded. On each surface, BC liquid was applied and rinsed with water after 3 min (baseline). All surfaces were checked by two independent observers for presence of blue areas. On each sample, one side was covered by nail varnish to protect this enamel part from demineralization. The samples were demineralized with lactic acid (pH 4.6) for 7 days (group A and C) and 14 days (group B and D), respectively. Mineral loss was determined using quantitative light-induced fluorescence after demineralization. BlueCheck dye was again applied on the samples and evaluated for presence of stained areas. Histological sections were prepared from randomly selected samples and lesion depth was measured. Kruskal-Wallis test was used for group comparison (α = 0.05). After demineralization, median ΔF value for all samples was -8.25% indicating the presence of an initial demineralization. The difference of ΔF values was not statistically significant between samples at 7 or 14 days of demineralization, nor for samples with and without orthodontic brackets (p = 0.13). At baseline, none of the sample surfaces showed discoloration, whereas a distinctive blue color was visible after demineralization in all samples exposed to acid-exposed areas, corresponding to 100% sensitivity. The internal control surfaces (without demineralization) did not show any staining, corresponding to 100% specificity. Histologically measured lesion depths ranged between 200 and 254 µm. In this in vitro study, staining of demineralized enamel surface areas were shown to be reliable. Based on our results, this easily applicable product seems useful to be an adjuvant method to clinical examination to monitor oral health during an orthodontic treatment on tooth surfaces after removal of dental biofilm.

Fluoride concentration in teas derived from Camellia Sinensis produced in Argentina.

To evaluate the fluoride concentration and pH of tea derived from Camellia sinensis produced and commercialized in Argentina. Forty-eight varieties of tea (black (n = 16), green (n = 21), red (n = 7), and white (n = 4)) commercialized in the form of leaves or tea bags were acquired. One bag or 2.0 ± 0.05 g of each product was infused for 5 min in 200 mL of distilled boiled water. The F- concentration was determined using an ion-selective electrode and pH was measured using a pH meter. The found fluoride concentrations ranged from 0.1 to 9.7 µg/mL and the pH ranged from 2.7 to 5.1. A higher fluoride concentration was observed in the leaves group (2.75 ± 2.65 µg/mL) compared to tea bags (1.10 ± 0.82 µg/mL) (p < 0.05). Regarding the type of tea, green and black tea were richer in F- than red and white tea. Fluoride and pH appeared not to be correlated (Pearson test). All the studied tea samples presented fluoride concentrations greater than the threshold recommended for drinking water. The pH proved to be low, which could be a risk for erosive tooth wear.

Prevalence, Caries, Dental Anxiety and Quality of Life in Children with MIH in Brussels, Belgium.

Molar incisor hypomineralisation (MIH) is a dental enamel pathology responsible for unfavorable functional and aesthetic implications. The objective of this study is to assess the prevalence, dental anxiety, and quality of life related to oral health in children with MIH. In 14 schools in Brussels, Belgium, 290 children aged 8 to 9.5 answered Children's Fear Survey Schedule-Dental Subscale (CFSS-DS) and Child-Oral Impact on Daily Performance (C-OIDP) questionnaires to assess dental anxiety and quality of life related to oral health (OHRQoL). Oral examinations allowed us to detect MIH according to standardized criteria. The MIH prevalence was 18.6%. The Decayed, Missing and Filled Teeth index (DMFT index) of MIH patients was significantly higher than non-MIH patients (p < 0.001), mainly due to more restored teeth. There was no significant association between MIH and dental anxiety or OHRQoL. Caries in the deciduous dentition was significantly associated with impaired quality of life. The MIH prevalence in Brussels is comparable to other European countries. MIH had no significant impact on dental anxiety and OHRQoL in this sample. The dynamic nature of MIH lesions requires early diagnosis and management to limit the evolution of the severity of the lesions and their implications. It is possible that older age groups may present more symptoms, however, this would require a longitudinal study.

Salivary Fluoride Bioavailability after Brushing with Brazilian Red Propolis Dentifrice: A Clinical Study.

INTRODUCTION: Fluoride plays an important role in the control of dental caries, and currently new dentifrices are being associated with natural products. OBJECTIVE: This study aimed to evaluate the availability of fluoride in saliva samples after using a dentifrice incorporated with Brazilian red propolis (BRP, INPI Patent no. BR1020170110974) and to compare it to a conventional fluoridated dentifrice in healthy participants. METHODS: This study was conducted implementing a double-blind, randomized, controlled, and crossover design. Saliva samples of participants were collected at the following time points: 0 at baseline and 5, 15, 30, 45, and 60 minutes after brushing with each dentifrice. Salivary fluoride concentrations showed no statistically significant difference when comparing the two treatments (p > 0.05). All available fluoride concentrations in saliva decreased after one hour, with no significant difference between BRP and conventional fluoridated dentifrice treatment samples (p > 0.05). RESULTS: The results showed that there was no difference between the analyzed fluoride concentrations 1 hour after brushing with the different dentifrices. CONCLUSIONS: The results of this study suggest that the propolis incorporated in the dentifrice did not interfere with the kinetics and bioavailability of the fluoride ion in saliva samples, enabling its integration with the pharmaceutical formula and thereby promoting its anti-inflammatory and antimicrobial benefits without compromising the anticaries activity of the formulation.

Evaluation of marginal and internal fit of lithium disilicate CAD-CAM crowns with different finish lines by using a micro-CT technique.

STATEMENT OF PROBLEM: Whether the precision of fit of computer-aided design and computer-aided manufacturing (CAD-CAM) complete crowns is affected by the finish line configuration is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the marginal and internal fit of CAD-CAM ceramic crowns made from lithium disilicate based on 3 different finish lines (rounded shoulder, chamfer, feather-edge). MATERIALS AND METHODS: Thirty anterior lithium disilicate complete crowns (n=10 per finish line group) were fabricated by following a completely digital workflow based on digital scans made with the TRIOS scanner. The crowns were adhesively cemented on duplicate dies of the respective prepared Typodont teeth, and the marginal gap, absolute marginal discrepancy, and internal gap were evaluated by using microcomputed tomography (µCT). A total of 66 values were obtained for each specimen from sagittal and transaxial sections, and a rendering software program was used to calculate the volume of the cement gap for each specimen by means of 3D region growing. Two-way ANOVA, Tukey post hoc tests with Bonferroni correction, and the Kruskal-Wallis test were used to compare the values between the experimental groups (α=.05). RESULTS: Marginal gap and absolute marginal discrepancy values were statistically significantly different between groups. In ascending order, marginal gap values were 23 ±14 µm for rounded shoulder, 54 ±28 µm for chamfer, and 96 ±36 µm for feather-edge finish lines. Absolute marginal discrepancy values were 96 ±34 µm for rounded shoulder, 124 ±37 µm for chamfer, and 157 ±34 µm for feather-edge finish lines. Internal gap values were 111 ±14 µm for feather-edge, 136 ±22 µm for chamfer, and 168 ±25 µm for rounded shoulder finish lines. The differences in cement volume between groups were not statistically significant (P=.200). CONCLUSIONS: All 3 finish lines produced marginal gaps within the range of clinically accep table values. Lithium disilicate CAD crowns with a rounded shoulder finish line had the best marginal fit but the poorest internal fit, and lithium disilicate CAD crowns with a feather-edge finish line had the best internal fit but the poorest marginal fit.

Behavior of Children during Dental Care with Rubber Dam Isolation: A Randomized Controlled Study.

BACKGROUND: The establishment of the dental dam improves dentist working conditions and patient protection. The purpose of this study was to analyze the behavior of the child during dental care with or without a dam. METHODS: In this interventional randomized study, 51 patients are divided into two groups, one with a rubber dam and the other with cotton roll isolation. Their behavior was observed during the treatment of temporary molars. The duration of the treatment, the patient's feeling with a visual analogue scale (VAS), the behavior (B) of the child measured with a hetero-evaluation scale (modified Venham scale) and the cardiac frequency (CF) were measured. RESULTS: The group treated with a rubber dam has a significant decrease in the various stress parameters that have been identified (B, p value = 0.034; CF, p value = 0.015). Subgroups of patients with and without nitrous oxide sedation were compared and similar results were obtained. CONCLUSIONS: Isolation with a rubber dam reduces child's stress during dental care. Although it is slightly more time-consuming and training is necessary for a quick and effective placement, it allows dentists to perform dental care in the best possible conditions, while reducing dental anxiety in young patients.

Dentist Related Factors Associated with Implementation of COVID-19 Protective Measures: A National Survey.

Little is known about the extent to which dentists have implemented COVID-19 infection control guidelines and the factors influencing this process in daily practice. This national online survey assessed the implementation of enhanced infection control guidelines in daily practice, and explored dentist related factors influencing their application, more specifically dentist infection status and their perceived risk of cross-infection in the dental setting. The survey was validated, pretested and carried out in 2020. A total of 1436 dentists participated, of whom 9.1% presumably had COVID-19 infection experience. At least 75% of dentists complied with the core part of the recommended protective measures protocol. For each patient treated during the pandemic, an additional cost of 10-30 EUR (86.7%) and an extra time of 10-30 min (70.7%) was estimated. A stepwise binary logistic regression analysis revealed that dentists assumed to have experienced COVID-19 reported a higher self-perceived risk of virus acquisition (ß = 2.090; p = 0.011), lower concern of getting infected (ß = 0.576; p = 0.027), and lower confidence in being able to prevent disease transmission in the dental setting (ß = 0.535; p = 0.022). Some parts of the protective measures were more difficult to apply than others; however, there was no indication of increased disease acquisition in the dental setting.

How to Intervene in the Caries Process in Older Adults: A Joint ORCA and EFCD Expert Delphi Consensus Statement.

AIM: To provide recommendations for dental clinicians for the management of dental caries in older adults with special emphasis on root caries lesions. METHODS: A consensus workshop followed by a Delphi consensus process were conducted with an expert panel nominated by ORCA, EFCD, and DGZ boards. Based on a systematic review of the literature, as well as non-systematic literature search, recommendations for clinicians were developed and consented in a two-stage Delphi process. RESULTS: Demographic and epidemiologic changes will significantly increase the need of management of older adults and root caries in the future. Ageing is associated with a decline of intrinsic capacities and an increased risk of general diseases. As oral and systemic health are linked, bidirectional consequences of diseases and interventions need to be considered. Caries prevention and treatment in older adults must respond to the patient's individual abilities for self-care and cooperation and often involves the support of caregivers. Systemic interventions may involve dietary counselling, oral hygiene instruction, the use of fluoridated toothpastes, and the stimulation of salivary flow. Local interventions to manage root lesions may comprise local biofilm control, application of highly fluoridated toothpastes or varnishes as well as antimicrobial agents. Restorative treatment is often compromised by the accessibility of such root caries lesions as well as the ability of the senior patient to cooperate. If optimum restorative treatment is impossible or inappropriate, long-term stabilization, e.g., by using glass-ionomer cements, and palliative treatments that aim to maintain oral function as long and as well as possible may be the treatment of choice for the individual.

How to intervene in the caries process in adults: proximal and secondary caries? An EFCD-ORCA-DGZ expert Delphi consensus statement.

OBJECTIVES: To provide consensus recommendations on how to intervene in the caries process in adults, specifically proximal and secondary carious lesions. METHODS: Based on two systematic reviews, a consensus conference and followed by an e-Delphi consensus process were held with EFCD/ORCA/DGZ delegates. RESULTS: Managing an individual's caries risk using non-invasive means (oral hygiene measures including flossing/interdental brushes, fluoride application) is recommended, as both proximal and secondary carious lesions may be prevented or their activity reduced. For proximal lesions, only cavitated lesions (confirmed by visual-tactile, or radiographically extending into the middle/inner dentine third) should be treated invasively/restoratively. Non-cavitated lesions may be successfully arrested using non-invasive measures in low-risk individuals or if radiographically confined to the enamel. In high-risk individuals or if radiographically extended into dentine, for these lesions, additional micro-invasive (lesion sealing and infiltration) treatment should be considered. For restoring proximal lesions, adhesive direct restorations allow minimally invasive, tooth-preserving preparations. Amalgams come with a lower risk of secondary lesions and may be preferable in more clinically complex scenarios, dependent on specific national guidelines. In structurally compromised (especially endodontically treated) teeth, indirect cuspal coverage restorations may be indicated. Detection methods for secondary lesions should be tailored according to the individual's caries risk. Avoiding false positive detection and over-treatment is a priority. Bitewing radiographs should be combined with visual-tactile assessment to confirm secondary caries detections. Review/refurbishing/resealing/repairing instead of replacing partially defective restorations should be considered for managing secondary caries, if possible. CONCLUSIONS: An individualized and lesion-specific approach is recommended for intervening in the caries process in adults. CLINICAL SIGNIFICANCE: Dental clinicians have an increasing number of interventions available for the management of dental caries. Many of them are grounded in the growing understanding of the disease. The best evidence, patients' expectations, clinicians' expertise, and the individual clinical scenario all need to be considered during the decision-making process.

How to Intervene in the Caries Process in Children: A Joint ORCA and EFCD Expert Delphi Consensus Statement.

This paper provides recommendations for dentists for the treatment of dental caries in children, with an emphasis on early childhood caries (ECC), primary teeth, and occlusal surfaces in permanent teeth. A consensus workshop followed by an e-Delphi consensus process was conducted with an expert panel nominated by the European Organization for Caries Research (ORCA) and European Federation of Conservative Dentistry (EFCD)/German Association of Conservative Dentistry (DGZ) boards. Based on 3 systematic reviews and a nonsystematic literature search, recommendations were developed. The caries decline has led to a more polarized disease distribution in children and adolescents along social gradients which should be taken into account when managing the caries process at all levels, such as the individual, the group, or a population. The control or reduction of caries activity is the basis for successful caries management. In children, caries management requires adequate daily oral hygiene and fluoride application via toothpaste, ensured by caregivers, and especially for ECC prevention an emphasis on sugar intake reduction is needed. These noninvasive interventions are also suitable to arrest or control initial or even cavitated dentine caries lesions in the absence of irreversible pulpitis. Fluoride varnish or silver diammine fluoride can be added as supplementary agents. In pits and fissures, composite resin materials can be used as preventive sealants and for defect-oriented minimally invasive restorations. In primary molars, preformed metal crowns are more successful than multisurface fillings, especially in caries-active patients. With persisting high caries activity, multiple lesions, and limited cooperation, caries control should consist of robust measures with high success rates, even including extraction in selected cases. This applies especially to treatments performed under general anesthesia.

Oral appliances in the treatment of oromandibular dystonia: a systematic review.

Oromandibular dystonia (OMD) is a clinically and etiologically heterogeneous form of focal dystonia with variable social and functional implications. The results of pharmacological treatment and botulinum toxin infiltrations are often unsatisfactory. We performed a systematic review on the effects of oral and dental appliances in patients with OMD. Most of the reports in the literature are single subject descriptions or small case series with a considerable variability in the type of dystonia, the type of evaluated appliances and in the outcome measures. Only one report included a large group of unselected patients that were evaluated with a mixture of outcome measures. Although it appears that a number of OMD patients, especially those who benefit from sensory tricks, may sustain some improvement with the use of oral appliances, no definitive conclusions can be drawn about the type of patients that may benefit, nor about the preferred type or mode of appliance. More research in this field is needed, using standardized approaches and clearly defined outcome measures in larger cohorts of OMD patients that are clinically and diagnostically well characterized.

Secondary caries: what is it, and how it can be controlled, detected, and managed?

OBJECTIVES: To assess how to control, detect, and treat secondary caries. This review serves to inform a joint ORCA/EFCD consensus process. METHODS: Systematic and non-systematic reviews were performed or consulted and narratively synthesized. RESULTS: Secondary (or recurrent) caries is defined as a lesion associated with restorations or sealants. While the restorative material itself has some influence on secondary caries, further factors like the presence and size of restoration gaps, patients' caries risk, and the placing dentist's experience seem more relevant. Current detection methods for secondary caries are only sparsely validated and likely prone for the risk of over-detection. In many patients, it might be prudent to prioritize specific detection methods to avoid invasive overtreatment. Detected secondary caries can be managed either by repair of the defective part of the restoration or its complete replacement. CONCLUSIONS: There is sparse data towards the nature of secondary caries and how to control, detect, and treat it. CLINICAL SIGNIFICANCE: Despite often claimed to be a major complication of restorations, there is surprisingly little data on secondary caries. Longer-term studies may be needed to identify differences in secondary caries risk between materials and to identify characteristic features of progressive lesions (i.e., those in need of treatment).

Stimuli involved in dental anxiety: What are patients afraid of?: A descriptive study.

BACKGROUND: Dental anxiety is a psychological response inducing aversion following a dental ill-defined stimulus, non-imminent and perceived as potentially dangerous. It is better to intervene during childhood than to resolve in adulthood when dental anxiety is more settled. AIM: The purpose of this study is to determine the nature of dental anxiety-provoking stimuli in young patients. DESIGN: A questionnaire was submitted to 566 children between 3 to 18 years in health institutions and schools in Brussels, Belgium. The items were divided into 3 groups: environment (ENV), local anaesthesia (LA), and intervention (INT) and summarized through averaging per group. Descriptive analysis and non-parametric testing were combined with logistic regression after discretization, above mild, for the group averages. RESULTS: About 7.2% of the respondents expressed high to severe dental anxiety. Several items presented a clear bimodal distribution dividing the population in fearless and fearing patients, for example, sight and feel of the syringe, sight and taste of blood and extraction. Others presented with a gradually lower incidence with increasing fear level. Fear for the environment was generally low. Gender and ethnic origin contribute significantly to the prediction of fear caused by LA. For fear caused by INT, first the place of questioning enters the models, thereafter follow: negative experience, frequency of dental visit, and gender (P < .05). CONCLUSIONS: While the dental environment is in general not causing fear, the invasive part of the anaesthesia and the invasive dental procedures are involved. Fear seems to be related to culture, previous experience, and gender.

Oral health and healthcare utilization in Belgian dentate adults.

OBJECTIVES: In 2012-2014, the Belgian National Oral Health Data Registration and Evaluation Survey, integrated in the Health Interview Survey (HIS), was carried out. The present study investigated, in a sample of 1340 dentate adults (≥25 years), the association between oral healthcare utilization, oral health status and sociodemographic status. METHODS: A multistage, stratified cluster sampling procedure was used. Oral examination for caries experience (World Health Organization, D3 MFT-Index), periodontal status (Dutch Periodontal Screening Index, DPS-Index), number of teeth present and occlusal contacts without wearing removable dentures was performed by calibrated examiners. Oral healthcare utilization data were retrieved from the records of the Belgian Intermutualistic Agency. Participants' oral health and sociodemographic data were linked to registered oral care utilization in the previous 5-year period. Regular attenders (annual attenders and those with at least one registered contact in three different years) were compared with irregular attenders (those having had dental visits but not according to the definition of regular attenders) and nonattenders. Data were weighted to compensate for sampling and participation bias. RESULTS: Six hundred and seventy-nine participants attended regularly, of whom 276 annually; 256 did not attend in the reference period. The overall D3 MFT-Index was not noticeably different between attendance patterns (varying between 11 and 13), although regular attenders had more restored teeth than nonattenders (P < 0.01). No difference was seen for DPS-Index and number of teeth/occluding pairs (χ2 test, P > 0.05). Females, participants with higher education, older participants and those in employment had higher rates of regular attendance. CONCLUSIONS: Regular attenders had fewer untreated caries lesions, but neither lower caries experience nor lower DPS-Index than irregular attenders. Regular attendance was associated with sociodemographic variables.

School Food Policies Related to Soft Drink and Fruit Juice Consumption as a Function of Education Type in Flanders, Belgium.

Recent data on erosive tooth wear (ETW) in Belgium have associated a vocational/technical type of education with ETW risk. Since the role of schools is essential to the promotion of healthy diets, this study aimed to investigate school food policies (SFP) related to soft drink and fruit juice consumption and to detect differences among schools in Flanders, Belgium (BE-F). An online questionnaire related to the control of acidic beverages and promotion of healthy drinking habits was sent to all Flemish secondary schools. For analysis, schools (n = 275) were grouped by type of education (vocational secondary education (VSE) and general secondary education (GSE)), and by socioeconomic status. Multiple factor analyses (MFA) were performed to identify schools with a similar SFP profile. Additionally, descriptive analyses were performed to determine other associations. Overall, 44% of schools in BE-F claimed to have written SFP related to the consumption of soft drinks. SFP expressly prohibiting or limiting acidic beverages were significantly more frequent in GSE schools (p < 0.05), where a higher economic status was present. This study shows that a considerable group of schools in BE-F have no or incomplete rules concerning acidic beverage consumption. Such rules differ between types of education, with VSE schools reporting less control regarding the consumption of drinks.

Grey value contrast sensitivity of dental practitioners in function of luminance and age.

OBJECTIVES: Grey value perception is important in viewing and interpreting X-ray images. It is possible that ageing decreases the number of gray values that a person can distinguish. This hypothesis was tested in a group of dental practitioners from students to experienced dentists using a 12-bit grey scale. METHODS AND MATERIALS: A custom-made computer software was used based on the principle of the "just noticeable difference" (JND). Observers were shown a picture of an outer square with increasing grey value in which a smaller square of different grey value popped up in changing positions. As soon as the observers could see the difference, they clicked the inner square. The grey values were shown with a 12-bit depth in batches of 400 grey value steps. 59 dentists of 3 age groups (20-24, 25-45 and 46-70 years) participated in the study. A subgroup of 20 practitioners performed a validation test with test-retest and test in reversed grey value sequence (white to black). JND was calculated and plotted against grey value using a third-order polynomial function. These curves were compared statistically. RESULTS: Test-retest, also in reversed order did not yield different curves (p values between 0.79 and 0.97). Curves between different age groups showed significant differences, with older practitioners needing more contrast to accomplish the task. Contrast sensitivity showed an optimum in the darker third of the grey scale (values around 1200). CONCLUSION: Age and grey value played a significant role in grey value perception by dental practitioners.

European Organization for Caries Research Workshop: Methodology for Determination of Potentially Available Fluoride in Toothpastes.

Toothpastes are the most universally accepted form of fluoride delivery for caries prevention. To provide anti-caries benefits, they must be able to release fluoride during the time of tooth brushing or post brushing into the oral cavity. However, there is no standard accepted procedure to measure how much fluoride in a toothpaste may be (bio) available for release. The European Organization for Caries Research proposed and supported a workshop with experts in fluoride analysis in toothpastes and representatives from industry. The objective of the workshop was to discuss issues surrounding fluoride analysis in toothpaste and reach consensus on terminology and best practices, wherever the available evidence allowed it. Participants received a background paper and heard presentations followed by structured discussion to define the problem. The group also reviewed evidence on the validity, reliability and feasibility of each technique (namely chromatography and fluoride electroanalysis) and discussed their strengths and limitations. Participants were able to reach a consensus on terminology and were also able to identify and summarize the advantages and disadvantages of each technique. However, they agreed that most currently available methods were developed for regulatory agencies several decades ago, utilizing the best available data from clinical trials then, but require to be updated. They also agreed that although significant advances to our understanding of the mechanism of action of fluoride in toothpaste have been achieved over the past 4 decades, this clearly is an extraordinarily complex subject and more work remains to be done.