Caries Detection on Intraoral Images Using Artificial Intelligence.

Although visual examination (VE) is the preferred method for caries detection, the analysis of intraoral digital photographs in machine-readable form can be considered equivalent to VE. While photographic images are rarely used in clinical practice for diagnostic purposes, they are the fundamental requirement for automated image analysis when using artificial intelligence (AI) methods. Considering that AI has not been used for automatic caries detection on intraoral images so far, this diagnostic study aimed to develop a deep learning approach with convolutional neural networks (CNNs) for caries detection and categorization (test method) and to compare the diagnostic performance with respect to expert standards. The study material consisted of 2,417 anonymized photographs from permanent teeth with 1,317 occlusal and 1,100 smooth surfaces. All the images were evaluated into the following categories: caries free, noncavitated caries lesion, or caries-related cavitation. Each expert diagnosis served as a reference standard for cyclic training and repeated evaluation of the AI methods. The CNN was trained using image augmentation and transfer learning. Before training, the entire image set was divided into a training and test set. Validation was conducted by selecting 25%, 50%, 75%, and 100% of the available images from the training set. The statistical analysis included calculations of the sensitivity (SE), specificity (SP), and area under the receiver operating characteristic (ROC) curve (AUC). The CNN was able to correctly detect caries in 92.5% of cases when all test images were considered (SE, 89.6; SP, 94.3; AUC, 0.964). If the threshold of caries-related cavitation was chosen, 93.3% of all tooth surfaces were correctly classified (SE, 95.7; SP, 81.5; AUC, 0.955). It can be concluded that it was possible to achieve more than 90% agreement in caries detection using the AI method with standardized, single-tooth photographs. Nevertheless, the current approach needs further improvement.

Best clinical practice guidance for prescribing dental radiographs in children and adolescents: an EAPD policy document.

BACKGROUND: The European Academy of Paediatric Dentistry (EAPD) proposes this best clinical practice guidance to help practitioners decide when and how to prescribe dental radiographs in children and adolescents. METHODS: Four expert working groups conducted each a systematic review of the literature. The main subjects were radiation protection, intraoral dental radiography (bitewing and periapical radiographs), panoramic radiography (PR) and cone-beam computed tomography (CBCT). In addition, three workshops were held during the corresponding EAPD Interim Seminar in Chania (Crete, Greece) in 2019. On the basis of the identified evidence, all invited experts presented their findings and during the workshops aspects of clinical relevance were discussed. RESULTS: Several clinical-based recommendations and statements were agreed upon. CONCLUSION: There is no or low-grade evidence about the efficacy of dental radiographic examinations in young populations. The given recommendations and rationales should be understood as best clinical practice guidance. It is essential to respect the radiological principles of an individualized and patient-specific justification. When a dental radiograph is required, its application needs to be optimized, aiming at limiting the patient's exposure to ionising radiation according to the ALADAIP principle (As Low As Diagnostically Achievable being Indication-oriented and Patient-specific).

Best clinical practice guidance for local analgesia in paediatric dentistry: an EAPD policy document.

BACKGROUND: The European Academy of Paediatric Dentistry (EAPD) proposes this best-practice guidance to help practitioners to decide when and how to use local analgesia to control pain in children, adolescents, and medically compromised individuals during the delivery of oral health care. METHODS: A search of different databases was conducted using all terms relevant to the subject. Relevant papers were identified after a review of their titles, abstracts or full papers. Three workshops were held during the corresponding EAPD interim seminar in Torino (Italy) in 2017. Several statements were agreed upon and, furthermore, knowledge gaps were identified. RESULTS: An important outcome was that when local analgesia administered appropriately-correct choice of agent(s) and dosage, proper route of administration-it is, firstly, clinically effective for pain-control in treating children and, secondly, it carries a very low risk of morbidity including adverse or side-effects. Furthermore, several gaps in knowledge were identified during the workshop which indicates future research needs. Most importantly it remains unsatisfactory that in several European countries the most frequently used injectable local analgesic agent, articaine, is not approved for usage in children below the age of 4 years. CONCLUSION: When considering the dental demand to treat vulnerable (medically compromised) children and adolescents in a safe, painless, less-invasive and effective way, there seems to be an urgent need to close these gaps in knowledge.

The need for repeated dental care under general anaesthesia in children.

AIM: Though the use of advanced behaviour management may facilitate dental treatment in children, some patients still require comprehensive care under general anaesthesia (GA). This is especially true for young children and/or medically compromised children. Thus, this study aimed to provide information about children undergoing GA with regard to age, sex and medical conditions (ICD-10), repeated treatments, dental procedures and recall. MATERIALS AND METHODS: A total of 464 medically compromised children treated under GA in a dental university clinic between 2004 and 2012 were included. Patients` records were analysed retrospectively using SPSS (Version 21.0) and R for statistical analysis. RESULTS: More than 75% of the patients were younger than six years when receiving initial GA. The proportion of children subjected to repeated treatments was low, at 11% for a second and <2% for a third round of GA. The greatest proportion of dental care consisted of restorative therapy and tooth extractions. The recall behaviour observed between the first and second GA revealed no significant influence on the time elapsed in between events (p>0.05). CONCLUSION: Oral care in children with medical conditions is mostly caries-related, and repeated treatment may be necessary, though it was generally uncommon in this university-based study population.

Best clinical practice guidance for management of early caries lesions in children and young adults: an EAPD policy document.

BACKGROUND: The European Academy of Paediatric Dentistry (EAPD) encourages prevention and arrest of active dental caries. Therefore, the present guidance provides evidence- and clinically-based recommendations for detecting and diagnosing early/non-cavitated caries lesions, risk assessment and disease management. METHODS: A search of different databases was conducted using all terms related to the subject. Relevant papers were identified after a review of their titles, abstracts or full texts. Three workshops were held during the corresponding EAPD interim seminar in Brussels in 2015. Several statements were agreed upon and, furthermore, gaps in our knowledge were identified. RESULTS: Following the systematic reviews and outcomes of the seminars, it was concluded that visual and radiographic caries detection should be utilised as a basic diagnostic approach to locate, assess and monitor non-cavitated caries lesions in primary and permanent teeth. As another important evaluation step, a caries risk assessment should be performed at a child's first dental visit, and reassessments should be performed on a regular basis. It is widely accepted that non-cavitated caries lesions can be managed non-invasively in the majority of cases. The spectrum of measures includes a low cariogenicity tooth-friendly diet, daily and appropriate management of the biofilm, home and within the dental office/surgery usage of fluorides as well as sealing techniques. CONCLUSION: The detection and management of non-cavitated caries is an essential aspect of preventive dentistry. Therefore, the EAPD encourages oral health care providers and caregivers to implement preventive practices that can arrest early caries and improve individual and public dental health.

Treatment strategies and outcomes of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with characterization of patients: a systematic review.

The aim of this systematic review was to answer the question: What are the treatments available for bisphosphonate-related osteonecrosis of the jaws (BRONJ) and their outcomes? A literature search of PubMed, Cochrane Library, and Web of Science databases was conducted in accordance with the PRISMA statement, search phrases were ('jaw osteonecrosis' OR 'bisphosphonate-related osteonecrosis' OR 'bisphosphonate osteonecrosis') AND ('treatment' OR 'outcomes'). Ninety-seven articles published between 2003 and February 2014 were reviewed. The studies reported 4879 cases of BRONJ. The mean age of the patients was 66.5 ± 4.7 years. The male to female ratio was 1:2. The mean duration of bisphosphonate (BP) administration was 38.2 ± 15.7 months. The quality of the publications was good, with some moderate and poor. Minimally invasive surgical treatment was the treatment most used. Medical treatment was also used. Adjunctive treatments included laser, growth factors, hyperbaric oxygen and ozone. The articles provided a broad range of outcome variables to assess the treatment of BRONJ and the outcomes of each treatment. Considerable heterogeneity was found regarding study design, sample size, and treatment modalities. Clinical trials with larger samples are required to provide sufficient information for each treatment modality to predict the outcomes of each treatment.

Occlusal caries extension in relation to visual and radiographic diagnostic criteria: results from a microcomputed tomography study.

OBJECTIVE: This in vitro study aimed to evaluate occlusal caries extension in relation to visual and radiographic diagnostic criteria and their clinical value to indicate operative or preventive dental care. METHODS: A total of 196 third molars with clinically sound occlusal fissures or noncavitated lesions were collected. Before microcomputed tomography (µCT) investigation, each tooth was examined visually and radiographically. Kühnisch's µCT-based caries-extension index (CE index) was used to determine the caries depth on a numeric scale (0 = sound; 0.01-0.99 = enamel caries; 1.0-1.99 = dentin caries). Sensitivities (SEs), specificities (SPs), and area under the receiver operating characteristic curve (Az value) were also calculated. RESULTS: Based on µCT data, the following mean CE index values and standard deviations (SDs) were documented according to the visual criteria: sound = 0.6 (0.4); first visible signs = 0.9 (0.4); established lesions = 1.3 (0.3); microcavities = 1.4 (0.2); dentin exposure = 1.5 (0.2); and large cavities = 1.5 (0.3). The radiographic categories according to Marthaler (enamel caries [D0-2], caries in the outer half of dentin [D3], and caries in the inner half of dentin [D4]) were related to CE index values of 0.9 (0.4), 1.4 (0.2) and 1.6 (0.4), respectively. Caries detected visually or radiographically showed an SE of 84% and an SP of 85% (Az = 0.85). When both methods were used to predict dentin involvement simultaneously, SE = 27%, SP = 100%, and Az = 0.63; this combined visual and radiographic approach was associated with a perfect specificity and no false-negative decisions. The proportion of false-positive diagnoses was moderately high, and lesion extension in these cases was mainly limited to the outer 20% of the dentin. CONCLUSIONS: Our results might be useful for differentiating between preventive and operative dental care for pits and fissures.

Elevated serum 25(OH)-vitamin D levels are negatively correlated with molar-incisor hypomineralization.

To date, the precise etiology of molar-incisor hypomineralization (MIH) is uncertain. Vitamin D plays a key role in hard tissue formation. Therefore, this study aimed to analyze the relationship between serum 25-hydroxy-vitamin D (25(OH)D) status and dental health data obtained from 1,048 children in a 10-year follow-up of the Munich GINIplus and LISAplus birth cohorts. The dental examination included the diagnosis of MIH and recording of (non-)cavitated caries lesions in primary and permanent teeth. Serum 25(OH)D concentrations were taken from blood samples of the 10-year investigation and measured with a fully automated, modular system. Different logistic regression and Poisson hurdle models were calculated. MIH was diagnosed in 13.6% of the study population. Approximately 16.4% of the children demonstrated caries-related defects (D3-4MFS > 0). The mean season-adjusted concentration of 25(OH)D was 75.8 nmol/l (standard deviation 22.0 nmol/l). After adjusting for sex, age, body mass index, parental education, equivalent income, and television/personal computer (TV/PC) viewing hours, a 10 nmol/l increase in serum 25(OH)D concentrations was significantly associated with a lower odds ratio of having MIH (OR = 0.89; P = 0.006). Furthermore, higher 25(OH)D values were associated with a lower number of caries-affected permanent teeth. It is concluded that elevated serum 25(OH)D concentrations were associated with better dental health parameters.

Feasibility and quality development of biomaterials in the pretest studies of the German National Cohort.

BACKGROUND: The German National Cohort (GNC) is designed to address research questions concerning a wide range of possible causes of major chronic diseases (e.g. cancer, diabetes, infectious, allergic, neurologic and cardiovascular diseases) as well as to identify risk factors and prognostic biomarkers for early diagnosis and prevention of these diseases. The collection of biomaterials in combination with extensive information from questionnaires and medical examinations represents one of the central study components. OBJECTIVES: In two pretest studies of the German National Cohort conducted between 2011 and 2013, a range of biomaterials from a defined number of participants was collected. Ten study centres were involved in pretest 1 and 18 study centres were involved in pretest 2. Standard operation procedures (SOP) were developed and evaluated to minimize pre-analytical artefacts during biosample collection. Within the pretest studies different aspects concerning feasibility of sample collection/preparation [pretest 1 (a)] and quality control of biomarkers and proteome analyses were investigated [pretest 1 (b), (c)]. Additionally, recruitment of study participants for specific projects and examination procedures of all study centres in a defined time period according to common standards as well as transportation and decentralized storage of biological samples were tested (pretest 2). These analyses will serve as the basis for the biomaterial collection in the main study of the GNC starting in 2014. MATERIALS AND METHODS: Participants, randomly chosen from the population (n = 1000 subjects recruited at ten study sites in pretest 1) were asked to donate blood, urine, saliva and stool samples. Additionally, nasal and oropharyngeal swabs were collected at the study sites and nasal swabs were collected by the participants at home. SOPs for sample collection, preparation, storage and transportation were developed and adopted for pretest 2. In pretest 2, 18 study sites (n = 599 subjects) collected biomaterials mostly identical to pretest 1. Biomarker analyses to test the quality of the biomaterials were performed. RESULTS: In pretest 1 and 2, it was feasible to collect all biomaterials from nearly all invited participants without major problems. The mean response rate of the subjects was 95 %. As one important result we found for example that after blood draw the cellular fraction should be separated from the plasma and serum fractions during the first hour with no significant variation for up to 6 h at 4 ℃ for all analysed biomarkers. Moreover, quality control of samples using a proteomics approach showed no significant clustering of proteins according to different storage conditions. All developed SOPs were validated for use in the main study after some adaptation and modification. Additionally, electronic and paper documentation sheets were developed and tested to record time stamps, volumes, freezing times, and aliquot numbers of the collected biomaterials. DISCUSSION: The collection of the biomaterials was feasible without major problems at all participating study sites. However, the processing times were in some cases too long. To avoid pre-analytical artefacts in sample collection, appropriate standardisation among the study sites is necessary. To achieve this, blood and urine collection will have to be adapted to specific conditions of usage of liquid handling robots, which will be available at all participating study centres in the main study of the GNC. Strict compliance with the SOPs, thorough training of the staff and accurate documentation are mandatory to obtain high sample quality for later analyses. The so obtained biomaterials represent a valuable resource for research on infectious and other common complex diseases in the GNC.

Clinical success of stainless steel crowns placed under general anaesthesia in primary molars: an observational follow up study.

AIM: Quality assessment of stainless steel crowns (SSCs) placed in primary molars of high caries risk children after 1, 3 and 5 years of service time. MATERIAL AND METHODS: Out of 1149 SSCs placed 1, 3 or 5 years before the evaluation period in 558 children, 428 (37.2%) SSCs were clinically evaluated in 171 (30.6%) children aged between 1.1 and 8.6 years. Marginal adaptation, extension and proximal contacts of SSCs, plaque and gingival bleeding at SSC were assessed. Caries experience was recorded by WHO standards. RESULTS: Caries experience was 7.8 dmft/18.4 dmfs before treatment. The overall success rate of SSCs was 97.2%, regardless of the extent of carious lesions or pulp treatment of the tooth. Loss of SSCs (1.9%), pathological tooth mobility (0.7%) and perforation of the crown (0.2%) were scored as clinical failures. The majority of SSCs had sealed margins and the marginal extension reached sub-gingival level. Open proximal contacts occurred mesially and distally (21.7%, 20%). All qualitative defects increased with service time. Secondary caries was not diagnosed. Of the SSCs, 46.4% were free of dental plaque. Gingival bleeding after probing was observed in 72.1% of all SSCs. Gingivitis was significantly associated with increased dmft-values (OR=1.108, 95%CI: 1.03-1.19) and plaque at SSCs (OR=0.29, 95%CI: 0.18-0.47). Children with migration background exhibited significantly more often insufficient oral hygiene and higher rates of gingival bleeding and caries experience than did German children. CONCLUSIONS: SSCs are clinically successful restorations in primary molars of high caries risk children. High caries prevalence and insufficient oral hygiene were greater determining factors for the occurrence of gingivitis than the quality of the SSCs.

ClC-7 expression levels critically regulate bone turnover, but not gastric acid secretion.

Mutations in the 2Cl(-)/1H(+)-exchanger ClC-7 impair osteoclast function and cause different types of osteoclast-rich osteopetrosis. However, it is unknown to what extent ClC-7 function has to be reduced to become rate-limiting for bone resorption. In osteoclasts from osteopetrosis patients expression of the mutated ClC-7 protein did not correlate with disease severity and resorption impairment. Therefore, a series of transgenic mice expressing ClC-7 in osteoclasts at different levels was generated. Crossing of these mice with Clcn7(-/-) mutants rescued the osteopetrotic phenotype to variable degrees. One resulting double transgenic line mimicked human autosomal dominant osteopetrosis. The trabecular bone of these mice showed a reduction of osteoblast numbers, osteoid, and osteoblast marker gene expression indicative of reduced osteoblast function. In osteoclasts from these mutants ClC-7 expression levels were 20 to 30% of wildtype levels. These reduced levels not only impaired resorptive activity, but also increased numbers, size and nucleus numbers of osteoclasts differentiated in vitro. Although ClC-7 was expressed in the stomach and PTH levels were high in Clcn7(-/-) mutants loss of ClC-7 did not entail a relevant elevation of gastric pH. In conclusion, we show that in our model a reduction of ClC-7 function by approximately 70% is sufficient to increase bone mass, but does not necessarily enhance bone formation. ClC-7 does not appear to be crucially involved in gastric acid secretion, which explains the absence of an osteopetrorickets phenotype in CLCN7-related osteopetrosis.

[Dental health of first molars among Westphalian immigrants and German students]. / Zahngesundheit erster Molaren bei westfälischen Migranten und deutschen Schülern.

The aim of this study was to assess the health status of the occlusal surface on the first molars of Westphalian students, of whom 41.0% were immigrants. The prevalence and retention of fissure sealants (FS) and caries experience was scored for 161 students aged 8 and 10 years. Logistic regression analysis was used to predict the influence of sex, ethnicity, and retention of FS on the occlusal caries risk of the first molars. There was no difference in caries prevalence and experience in 8-year-old German students and immigrants (5.6%/10.5%; 0.07 DMFT/0.21 DMFT), both parameters were significantly higher in 10-year-old immigrants than in German students (25.5%/9.5%; 0.55 DMFT/0.11 DMFT). The prevalence and number of molars with FS was not different between German students and immigrants at 8 years (39.1%, 1.28 FS; 33.8%, 0.94 FS) and at 10 years of age (47.4%, 1.68 FS; 39.4%, 1.17 FS). The occlusal caries risk of first molars without FS was significantly higher in 8-year-old immigrants than in German students (OR 4.62). FS should be used more frequently in daily dental practice. To improve the quality of FS, stricter implementation of guideline-based standards is required.

Irregularities below the enamel-dentin junction may predispose for fissure caries.

This study investigated the structure of the fissure fundus on occlusal surfaces with respect to the detection of possible irregularities below the enamel-dentin junction (EDJ). Occlusal surfaces were examined by micro-computed tomography (µCT). In total, 203 third molars with clinically sound occlusal fissures or non-cavitated lesions were selected. All specimens were scanned with µCT. Subsequently, each tooth was sectioned, and each slice was investigated by stereomicroscopy. In 7 of 203 molars (3.4%), demarcated radiolucencies below the EDJ were detected by µCT. These defects were obviously of non-carious origin, because the µCT images revealed no gradient of demineralization in the dentin. In all cases, a direct pathway between the oral cavity and the dentin was evident. The comparison of the µCT sites with conventional histological images also revealed defects in the dentin. These results demonstrate that demarcated radiolucencies below the EDJ may not necessarily be caries lesions according to µCT images and may be classified as possible developmental irregularities. To avoid misinterpreting µCT data, dental researchers should carefully consider this condition when analyzing µCT images. The clinical significance of this finding is that these defects may predispose molar teeth to early-onset caries in occlusal pits and fissures.

[Two German Birth Cohorts: GINIplus and LISAplus]. / Die zwei deutschen Geburtskohorten GINIplus und LISAplus.

Numerous chronic diseases in childhood and adulthood have their origins in perinatal life and are potentially influenced by trans-generational epigenetic processes. Therefore, prospective birth cohorts can substantially contribute to our knowledge about the etiology of diseases including modifiable risk factors. The two population-based German birth cohorts GINIplus and LISAplus aim to describe the natural course of chronic diseases and intermediate phenotypes in childhood and its determinants, and to identify potential genetic effect modifications. In the mid-1990s, 5,991 (GINIplus) and 3,097 (LISAplus) healthy, term newborns were recruited for long-term follow-up in four regions of Germany. The follow-up rate for the first 10 years was about 55%. We analyzed the growth and development of overweight, infections and allergic diseases, mental and oral health, metabolic and inflammatory parameters and the role of potential risk factors including genetics. The results of these two birth cohorts substantially contribute to the current knowledge about the natural course of these health parameters. These data were included in many international projects and consortia for purposes of international comparisons of prevalence and consistency of findings, and to increase the power of the analyses.

Fetal and postnatal mouse bone tissue contains more calcium than is present in hydroxyapatite.

It has been shown for developing enamel and zebrafish fin that hydroxyapatite (HA) is preceded by an amorphous precursor, motivating us to examine the mineral development in mammalian bone, particularly femur and tibia of fetal and young mice. Mineral particle thickness and arrangement were characterized by (synchrotron) small-angle X-ray scattering (SAXS) combined with wide-angle X-ray diffraction (WAXD) and X-ray fluorescence (XRF) analysis. Simultaneous measurements of the local calcium content and the HA content via XRF and WAXD, respectively, revealed the total calcium contained in HA crystals. Interestingly, bones of fetal as well as newborn mice contained a certain fraction of calcium which is not part of the HA crystals. Mineral deposition could be first detected in fetal tibia at day 16.5 by environmental scanning electron microscopy (ESEM). SAXS revealed a complete lack of orientation in the mineral particles at this stage, whereas 1day after birth particles were predominantly aligned parallel to the longitudinal bone axis, with the highest degree of alignment in the midshaft. Moreover, we found that mineral particle length increased with age as well as the thickness, while fetal particles were thicker but much shorter. In summary, this study revealed strong differences in size and orientation of the mineral particles between fetal and postnatal bone, with bulkier, randomly oriented particles at the fetal stage, and highly aligned, much longer particles after birth. Moreover, a part of the calcium seems to be present in other form than HA at all stages of development.

Comparison of visual inspection and different radiographic methods for dentin caries detection on occlusal surfaces.

OBJECTIVES: The aim of the present study was to assess the validity of the digital phosphor plate radiographic technique (Gendex Dental Systems) on occlusal surfaces in comparison with visual examination and conventional E- and F-speed films. METHODS: The study material consisted of 54 non-cavitated third molars with a range of appearances, including apparently sound surfaces. Each surface was visually examined (VI) according to the criteria established by Ekstrand et al. Three radiographic images (E-speed, F-speed, digital phosphor plate film) were taken of each molar. The standardized radiograph technique used an alignment fixture to reproduce the focus-to-object distance as well as the object-to-film distance. Afterwards each tooth was cut into sections in the buccolingual direction with a microtome saw, and caries extension was assessed using light microscopy (LM) and microradiography (MR). The statistical analysis included the calculation of sensitivity (SE), specificity (SP) and A(z) values. RESULTS: The following validity parameters were found for the tested diagnostic methods on the dentin caries level: VI/LM, 68.0 SE/93.1 SP/0.698 A(z); VI/MR, 68.2/87.5/0.751; E-speed/LM, 76.0/78.6/0.637; E-speed/MR, 77.3/74.2/0.681; F-speed/LM, 64.0/67.9/0.507; F-speed/MR, 68.2/67.7/0.594; Gendex/LM, 60.0/85.7/0.629; and Gendex/MR, 59.1/80.6/0.586. CONCLUSION: The methods used showed different levels of validity: E- and F-speed films were linked to higher sensitivity values, whereas a higher specificity was recorded for the tested imaging plate system. In accordance with the diagnostic performance, the digital system can be recommended for practical use and potentially help prevent overtreatment thanks to its high SP.

[Occlusal caries - early detection in school-based dental screenings]. / Okklusalkaries - frühzeitige Diagnostik in den schulischen Reihenuntersuchungen.

Concomitant to the general caries decline in children and adolescents, caries is mainly concentrated on occlusal surfaces of permanent molars. While occlusal cavities have been shifted to non-cavitated lesions, school-based visual tactile screenings on a cavity level based on the WHO standard (1997) are of limited value as evidence. To avoid cavities or extended restorations current dentistry targets at early prevention or minimal intervention. School-based visual screenings of non-cavitated lesions may support the preventive care strategies of dental practioners. A comparative diagnostic study in 8- to 12-year-olds in the Westfalian Ennepe-Ruhr district showed that occlusal surfaces scored as primarily sound under the WHO standard in fact revealed a high need for preventive (43%) and operative (30%) treatment after using additional visual and laser optical diagnostic measurements. Because of the limited information of the laser optical findings, laser fluorescence diagnostics should not be included in school-based dental screenings. Compromises are needed to introduce visual diagnostic examinations in school-based dental screenings.

Frequency of non-carious triangular-shaped radiolucencies on bitewing radiographs.

OBJECTIVES: The assessment of bitewing radiographs requires knowledge of radiographic anatomy and pathology, and the comprehension of possible effects of superposition which may lead to false positive diagnoses. Based on a clinical case report in which non-carious radiolucencies were discovered on the mesial surfaces of upper molars, this phenomenon, which has not been reported before, was explained. Due to the anatomical characteristics of the rhombic tooth, in particular the crown's receding mesial surface from the mesiobuccal towards the distopalatal side, which is combined with an often prominent palatal cusp and a smaller mesiodistal diameter at the cervical neck, radiolucencies - normally typical caries indicators - can sometimes be observed on the mesial surfaces of upper primary and first permanent molars on bitewings. These triangular-shaped radiolucencies (TSRs) can therefore be attributed to the effects of superposition. The aim of the present epidemiological study was to assess the radiographic frequency of TSRs. METHODS: As part of a clinical-radiographic follow-up examination involving 11-12 year old children (n = 113), both the caries status (World Health Organization (WHO) standard) and the frequency of TSRs were recorded. RESULTS: TSRs were most frequently present on upper second primary molars (60.3%). 35.5% of the upper first primary molars and 24.8% of the upper first permanent molars displayed TSRs. However, none of the lower primary and/or permanent molars displayed this phenomenon. CONCLUSION: In the mesial surface of upper primary and permanent molars where the frequency of TSRs was fairly high, it may be essential to distinguish this change from approximal caries.

[Dental health in German and Turkish school children--a 10-year comparison]. / Zahngesundheit deutscher und türkischer Schüler--Ein 10-Jahresvergleich.

The purpose of this cross-sectional study was to assess the changes in dental health in 12- and 15-year-old Turkish immigrants and German students who were included in a school-based caries-preventive programme for ten years (1993-2003). In 1993 352 and 402 12- and 15-year-olds and in 2003 352 and 402 12- and 15-year-olds were investigated, respectively. 23.6% of the 12-year-olds and 21.5% of the 15-year-olds were of Turkish origin. The clinical examination was performed with support of artificial light at school. Caries was diagnosed according to the WHO standard using the DMFT Index for permanent dentition. Within the ten-year period the highest increment of caries-free dentitions was found in 12- and 15-year old Germans attending grammar schools with 41,5% and 27% and secondary modern schools with 22,3% and 17%, respectively. The proportion of caries-free Turkish students attending secondary modern schools, only increased imperceptible in both age groups (1.2%). A significant caries decline of 1.5 DMFT was observed in 12-year old Germans at grammar schools, only. In 15-year olds caries declined in German students at secondary modern schools (2.5 DMFT), and at Grammar schools (2.2 DMFT), significantly, however caries experience in Turkish students remained nearly unchanged (0.3 DMFT). A strong polarisation of dental caries was found in 2003. Among the 12-year-olds 23% of those at secondary modern school accumulated 70% of the total caries experience (>3 DMFT) and at grammar school 9% of students accumulated 76% of the whole amount of caries (>1 DMFT). Among the 15-year-olds 73% of the total caries experience (>3 DMFT) was concentrated in 32% of the students at secondary modern schools, while 25% of the students at grammar schools exhibited 84% of the whole amount of caries (>1 DMFT). Intended concepts in caries prevention in the future should aim to improve dental health especially in Turkish students at secondary modern schools while taking social inequality of this risk group into account.