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Background: The identification of microbiota based on next-generation sequencing (NGS) of extracted DNA has drastically improved our understanding of the role of microbial communities in health and disease. However, DNA-based microbiome analysis cannot per se differentiate between living and dead microorganisms. In environments such as the skin, host defense mechanisms including antimicrobial peptides and low cutaneous pH result in a high microbial turnover, likely resulting in high numbers of dead cells present and releasing substantial amounts of microbial DNA. NGS analyses may thus lead to inaccurate estimations of microbiome structures and consequently functional capacities., Results: We investigated in this study the feasibility of a Benzonase-based approach (BDA) to pre-digest unprotected DNA, i.e., of dead microbial cells, as a method to overcome these limitations, thus offering a more accurate assessment of the living microbiome. A skin mock community as well as skin microbiome samples were analyzed using 16S rRNA gene sequencing and metagenomics sequencing after DNA extraction with and without a Benzonase digest to assess bacterial diversity patterns. The BDA method resulted in less reads from dead bacteria both in the skin mock community and skin swabs spiked with either heat-inactivated bacteria or bacterial-free DNA. This approach also efficiently depleted host DNA reads in samples with high human-to-microbial DNA ratios, with no obvious impact on the microbiome profile. We further observed that low biomass samples generate an α-diversity bias when the bacterial load is lower than 10 5 CFU and that Benzonase digest is not sufficient to overcome this bias., Conclusions: The BDA approach enables both a better assessment of the living microbiota and depletion of host DNA reads. Video abstract.

The gut microbiome is crucial for both maturation of the immune system and colonization resistance against enteric pathogens. Although chicken are important domesticated animals, the impact of their gut microbiome on the immune system is understudied. Therefore, we investigated the effect of microbiome-based interventions on host mucosal immune responses. Increased levels of IgA and IgY were observed in chickens exposed to maternal feces after hatching compared with strict hygienic conditions. This was accompanied by increased gut bacterial diversity as assessed by 16S rRNA gene amplicon sequencing. Cultivation work allowed the establishment of a collection of 43 bacterial species spanning 4 phyla and 19 families, including the first cultured members of 3 novel genera and 4 novel species that were taxonomically described. This resource is available at www.dsmz.de/chibac A synthetic community consisting of nine phylogenetically diverse and dominant species from this collection was designed and found to be moderately efficient in boosting immunoglobulin levels when provided to chickens early in life. IMPORTANCE The immune system plays a crucial role in sustaining animal health. Its development is markedly influenced by early microbial colonization of the gastrointestinal tract. As chicken are fully dependent on environmental microbes after hatching, extensive hygienic measures in production facilities are detrimental to the microbiota, resulting in low colonization resistance against pathogens. To combat enteric infections, antibiotics are frequently used, which aggravates the issue by altering gut microbiota colonization. Intervention strategies based on cultured gut bacteria are proposed to influence immune responses in chicken., (Copyright © 2021 Zenner et al.)

The composition of the microbiome is subject to the host's diet. In commercial laboratory mouse diets, different physical forms of the same diets are available, containing-according to their labels-identical ingredients and nutrient compositions. However, variations in nutrient composition and starch gelatinization due to production processes and their impact on digestibility have been described. In this study, a total of 48 C57BL/J6 mice were assigned to two equal groups and were fed diets (produced with different processes-extruded vs. pelleted) for eight weeks in two biological replicates. At the end of the experiment, samples were collected from five different gastrointestinal regions, including the stomach, small intestine, cecum, large intestine, and an extracorporeal region (feces), and the microbiome was analyzed with 16S rRNA gene amplicon sequencing. The replicates in both experiments differed significantly in their relative abundances of Muribaculaceae species. Furthermore, the gastrointestinal content of pellet-fed mice contained larger numbers of Lactobacillus species. These results indicate that starch gelatinization and ingredient composition significantly influence microbial makeup. In conclusion, different feed processing methods may affect fundamental digestive and metabolic processes, impacting animal experiments and biasing microbiome data.

Background: Little is known about the complex interactions between the diet, the gut microbiota, and enteropathogens. Here, the impact of two specific diets on the composition of the mouse gut microbiota and on the transcriptional response of Salmonella Typhimurium (S. Typhimurium) was analyzed in an enteritis model., Results: Mice were fed for two weeks a fibre-rich, plant-based diet (PD), or a Westernized diet (WD) rich in animal fat and proteins and in simple sugars, and then infected with an invasin-negative S. Typhimurium strain ST4/74 following streptomycin-treatment. Seventy-two hours post infection, fecal pathogen loads were equal in both diet groups, suggesting that neither of the diets had negatively influenced the ability of this ST4/74 strain to colonize and proliferate in the gut at this time point. To define its diet-dependent gene expression pattern, S. Typhimurium was immunomagnetically isolated from the gut content, and its transcriptome was analyzed. A total of 66 genes were more strongly expressed in mice fed the plant-based diet. The majority of these genes was involved in metabolic functions degrading substrates of fruits and plants. Four of them are part of the gat gene cluster responsible for the uptake and metabolism of galactitol and D-tagatose. In line with this finding, 16S rRNA gene amplicon analysis revealed higher relative abundance of bacterial families able to degrade fiber and nutritive carbohydrates in PD-fed mice in comparison with those nourished with a WD. Competitive mice infection experiments performed with strain ST4/74 and ST4/74 ΔSTM3254 lacking tagatose-1,6-biphosphate aldolase, which is essential for galactitol and tagatose utilization, did not reveal a growth advantage of strain ST4/74 in the gastrointestinal tract of mice fed plant-based diet as compared to the deletion mutant., Conclusion: A Westernized diet and a plant-based diet evoke distinct transcriptional responses of S. Typhimurium during infection that allows the pathogen to adapt its metabolic activities to the diet-derived nutrients. This study therefore provides new insights into the dynamic interplay between nutrient availability, indigenous gut microbiota, and proliferation of S. Typhimurium.

Short-amplicon 16S rRNA gene sequencing is currently the method of choice for studies investigating microbiomes. However, comparative studies on differences in procedures are scarce. We sequenced human stool samples and mock communities with increasing complexity using a variety of commonly used protocols. Short amplicons targeting different variable regions (V-regions) or ranges thereof (V1-V2, V1-V3, V3-V4, V4, V4-V5, V6-V8, and V7-V9) were investigated for differences in the composition outcome due to primer choices. Next, the influence of clustering (operational taxonomic units [OTUs], zero-radius OTUs [zOTUs], and amplicon sequence variants [ASVs]), different databases (GreenGenes, the Ribosomal Database Project, Silva, the genomic-based 16S rRNA Database, and The All-Species Living Tree), and bioinformatic settings on taxonomic assignment were also investigated. We present a systematic comparison across all typically used V-regions using well-established primers. While it is known that the primer choice has a significant influence on the resulting microbial composition, we show that microbial profiles generated using different primer pairs need independent validation of performance. Further, comparing data sets across V-regions using different databases might be misleading due to differences in nomenclature (e.g., Enterorhabdus versus Adlercreutzia ) and varying precisions in classification down to genus level. Overall, specific but important taxa are not picked up by certain primer pairs (e.g., Bacteroidetes is missed using primers 515F-944R) or due to the database used (e.g., Acetatifactor in GreenGenes and the genomic-based 16S rRNA Database). We found that appropriate truncation of amplicons is essential and different truncated-length combinations should be tested for each study. Finally, specific mock communities of sufficient and adequate complexity are highly recommended. IMPORTANCE In 16S rRNA gene sequencing, certain bacterial genera were found to be underrepresented or even missing in taxonomic profiles when using unsuitable primer combinations, outdated reference databases, or inadequate pipeline settings. Concerning the last, quality thresholds as well as bioinformatic settings (i.e., clustering approach, analysis pipeline, and specific adjustments such as truncation) are responsible for a number of observed differences between studies. Conclusions drawn by comparing one data set to another (e.g., between publications) appear to be problematic and require independent cross-validation using matching V-regions and uniform data processing. Therefore, we highlight the importance of a thought-out study design including sufficiently complex mock standards and appropriate V-region choice for the sample of interest. The use of processing pipelines and parameters must be tested beforehand., (Copyright © 2021 Abellan-Schneyder et al.)

Mushrooms are a rich source of dietary fiber. This study aimed to characterize the modulation of colonic microbiota in Zucker rats after supplementing their diet with a biotechnologically produced oyster mushroom ( Pleurotus sajor-caju ). Microbiota composition and short chain fatty acids (SCFAs) in the colon and bile acids in the plasma of the rats were analyzed to assess the effects of P. sajor-caju supplementation on the microbiota in the colon and its interplay with the host in the event of hepatic steatosis. Microbiota profiles were distinctly modulated by P. sajor-caju supplementation between the obese control rats and the obese rats fed the 5% P. sajor-caju -supplemented diet. P. sajor-caju enhanced the growth of SCFAs-producing bacterial genera, including Faecalibaculum , Bifidobacterium , Roseburia , and Blautia, and decreased the relative abundance of the pathogenic genus Escherichia - Shigella . This was also accompanied by distinct changes in the concentrations of bile acids in the plasma and concentrations of SCFAs in the colon, supporting the initial potentiality of P. sajor-caju as a prebiotic in cases of hepatic steatosis and liver inflammation.

The intestinal microbiome is implicated as an important modulating factor in multiple inflammatory 1,2 , neurologic 3 and neoplastic diseases 4 . Recent genome-wide association studies yielded inconsistent, underpowered and rarely replicated results such that the role of human host genetics as a contributing factor to microbiome assembly and structure remains uncertain 5-11 . Nevertheless, twin studies clearly suggest host genetics as a driver of microbiome composition 11 . In a genome-wide association analysis of 8,956 German individuals, we identified 38 genetic loci to be associated with single bacteria and overall microbiome composition. Further analyses confirm the identified associations of ABO histo-blood groups and FUT2 secretor status with Bacteroides and Faecalibacterium spp. Mendelian randomization analysis suggests causative and protective effects of gut microbes, with clade-specific effects on inflammatory bowel disease. This holistic investigative approach of the host, its genetics and its associated microbial communities as a 'metaorganism' broaden our understanding of disease etiology, and emphasize the potential for implementing microbiota in disease treatment and management.

Our knowledge about the gut microbiota of pigs is still scarce, despite the importance of these animals for biomedical research and agriculture. Here, we present a collection of cultured bacteria from the pig gut, including 110 species across 40 families and nine phyla. We provide taxonomic descriptions for 22 novel species and 16 genera. Meta-analysis of 16S rRNA amplicon sequence data and metagenome-assembled genomes reveal prevalent and pig-specific species within Lactobacillus, Streptococcus, Clostridium, Desulfovibrio, Enterococcus, Fusobacterium, and several new genera described in this study. Potentially interesting functions discovered in these organisms include a fucosyltransferase encoded in the genome of the novel species Clostridium porci, and prevalent gene clusters for biosynthesis of sactipeptide-like peptides. Many strains deconjugate primary bile acids in in vitro assays, and a Clostridium scindens strain produces secondary bile acids via dehydroxylation. In addition, cells of the novel species Bullifex porci are coccoidal or spherical under the culture conditions tested, in contrast with the usual helical shape of other members of the family Spirochaetaceae. The strain collection, called 'Pig intestinal bacterial collection' (PiBAC), is publicly available at www.dsmz.de/pibac and opens new avenues for functional studies of the pig gut microbiota.

Background: Sonic irrigant activation has gained widespread popularity among general dentists and endodontists alike in recent years. This in vitro study aimed to evaluate the impact of three power modes of a sonic activation device (EDDY) on its antimicrobial effectiveness in infected root canals., Methods: The root canals of straight, human roots (n = 120) were prepared to size 40/.06. In a short-term infection experiment, the root canals were inoculated with different microbial species for three days. The following irrigation protocols, using 4 ml of normal saline as irrigant, were performed: negative control, manual rinsing, sonic irrigant activation at power modes "low", "medium" and "high". In a second, long-term experiment, testing the same irrigation protocols, inoculation lasted 21 days and sodium hypochlorite was used as irrigant. Sequential infection control samples were assessed using culture assays. The statistical analysis included one-way analysis of variance of log 10 -scaled counts of colony-forming units (CFU) with post-hoc comparisons using Bonferroni corrections and Chi 2 tests (α = 0.05)., Results: In the short-term experiment, the sonic irrigation protocols decreased the number of CFUs by 1.88 log 10 units compared with the negative control (p < 0.001). The power modes "medium" and "high" achieved the most effective reduction of the microbial load. In the long-term experiment, microbial regrowth occurred after 7 days unless the device was used at its highest power setting., Conclusions: The power modes of the sonic irrigation device have a significant impact on the effectiveness for endodontic disinfection. The sonic irrigation device should always be used at the highest power setting in order to maximize its antimicrobial effectiveness.

Most endodontic infections are limited to the tooth and can be successfully treated by conventional root canal treatment without the need for local or systemic antibiotics. However, if there is evidence of systemic involvement and a rapid and diffuse spread of the infection, antibiotics may be indicated. Likewise, systemic prophylactic antibiotics may be indicated in risk patients with im­mune suppression. The current guidelines are summarized in this article.

Objectives: The aim of this in vivo prospective clinical study was to validate a near-infrared light transillumination (NILT) device for the detection of proximal caries lesions and compare it to the established diagnostic method of bitewing radiography (BWR)., Materials and Methods: A total of 116 interproximal posterior teeth/surfaces without gross cavitation were included and assessed with BWR and NILT. After clinical examination, the teeth with sound surfaces or non-cavitated caries lesions were separated with the use of an orthodontic separation rubber for 24h. Upon removal of the separator a silicon impression was obtained and the teeth surfaces were directly investigated. Intra- and inter-examiner reproducibility, sensitivities (SE) and specificities (SP) as well as the area under ROC curves (AUC) were calculated., Results: The SE of NILT was 0.92 in D 1 lesions and 1.00 in D 2 and D 3 lesions, respectively. BWR showed SE values of 0.81 in D 1 lesions, 0.74 in D 2 and 1.00 in D 3 lesions, respectively. However, NILT showed lower values of SP (D 1 0.38, D 2 0.42 and D 3 0.99) compared to BWR (D 1 0.65, D 2 0.88, D 3 1.00). Intra-examiner reproducibility increased for both examiners from the initial examination (0.68 and 0.62) to the recall appointment (0.89 and 0.76) respectively., Conclusion: The performance of NILT in detection of enamel caries was comparable to BWR. NILT could be considered as a useful and reliable tool in clinical practice. However, monitoring of enamel lesions might not be accurate, since a low specificity of NILT at D 1,2 level and a tendency to false positive ratings have been shown. Therefore, it is recommended that treatment decisions should not be based on NILT alone., Clinical Relevance: This study might indicate that NILT can be used for routine patient screening but the use of BWR is still important for treatment decisions., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: Extracellular DNA (eDNA) has been shown to be important for biofilm stability of the endodontic pathogen Enterococcus faecalis . In this study, we hypothesized that treatment with DNase prevents adhesion and disperses young E. faecalis biofilms in 96-well plates and root canals of extracted teeth., Methods: E. faecalis eDNA in 96-well plates was visualized with TOTO-1®. The effect of DNase treatment was assessed in 96-well plates and in extracted single-rooted premolars (n=37) using a two-phase crossover design. E. faecalis was treated with DNase (50 Kunitz/mL) or heat-inactivated DNase for 1 h during adhesion or after 24 h of biofilm formation. In 96-well plates, adhering cells were quantified using confocal microscopy and digital image analysis. In root canals, the number of adhering cells was determined in dentine samples based on colony forming unit counts. Data from the 96-well plate were analyzed using one-tailed t-tests, and data from extracted teeth were analyzed using mixed-effect Poisson regressions., Results: eDNA was present in wells colonized by E. faecalis after 1 h of adhesion and 24 h of biofilm formation; it was removed by DNase treatment, as evidenced by TOTO®-1 staining. DNase treatment reduced the area covered by cells in 96-well plates after 1 h (P<0.05), but not after 24 h (P=0.96). No significant differences in the number of adhering cells were observed in extracted teeth after 1 (P=0.14) and 24 h (P=0.98)., Conclusion: DNase treatment does not disperse endodontic E. faecalis biofilms. The sole use of DNase as an anti-biofilm agent in root canal treatments is not recommendable., Competing Interests: Conflict of interest: The authors deny any conflict of interest., (Copyright: © 2018 European Endodontic Journal.)

Background: Due to the DNA triplet code, it is possible that the sequences of two or more protein-coding genes overlap to a large degree. However, such non-trivial overlaps are usually excluded by genome annotation pipelines and, thus, only a few overlapping gene pairs have been described in bacteria. In contrast, transcriptome and translatome sequencing reveals many signals originated from the antisense strand of annotated genes, of which we analyzed an example gene pair in more detail., Results: A small open reading frame of Escherichia coli O157:H7 strain Sakai (EHEC), designated laoB (L-arginine responsive overlapping gene), is embedded in reading frame -2 in the antisense strand of ECs5115, encoding a CadC-like transcriptional regulator. This overlapping gene shows evidence of transcription and translation in Luria-Bertani (LB) and brain-heart infusion (BHI) medium based on RNA sequencing (RNAseq) and ribosomal-footprint sequencing (RIBOseq). The transcriptional start site is 289 base pairs (bp) upstream of the start codon and transcription termination is 155 bp downstream of the stop codon. Overexpression of LaoB fused to an enhanced green fluorescent protein (EGFP) reporter was possible. The sequence upstream of the transcriptional start site displayed strong promoter activity under different conditions, whereas promoter activity was significantly decreased in the presence of L-arginine. A strand-specific translationally arrested mutant of laoB provided a significant growth advantage in competitive growth experiments in the presence of L-arginine compared to the wild type, which returned to wild type level after complementation of laoB in trans. A phylostratigraphic analysis indicated that the novel gene is restricted to the Escherichia/Shigella clade and might have originated recently by overprinting leading to the expression of part of the antisense strand of ECs5115., Conclusions: Here, we present evidence of a novel small protein-coding gene laoB encoded in the antisense frame -2 of the annotated gene ECs5115. Clearly, laoB is evolutionarily young and it originated in the Escherichia/Shigella clade by overprinting, a process which may cause the de novo evolution of bacterial genes like laoB.

Objectives: The purpose of this in vitro study was to evaluate the inter- and intraexaminer reliability of digital bitewing (DBW) radiography and near-infrared light transillumination (NIRT) for proximal caries detection and assessment in posterior teeth., Methods: From a pool of 85 patients, 100 corresponding pairs of DBW and NIRT images (~1/3 healthy, ~1/3 with enamel caries and ~1/3 with dentin caries) were chosen. 12 dentists with different professional status and clinical experience repeated the evaluation in two blinded cycles. Two experienced dentists provided a reference diagnosis after analysing all images independently. Statistical analysis included the calculation of simple (κ) and weighted Kappa (wκ) values as a measure of reliability. Logistic regression with a backward elimination model was used to investigate the influence of the diagnostic method, evaluation cycle, type of tooth, and clinical experience on reliability., Results: Altogether, inter- and intraexaminer reliability exhibited good to excellent κ and wκ values for DBW radiography (Inter: κ = 0.60/ 0.63; wκ = 0.74/0.76; Intra: κ = 0.64; wκ = 0.77) and NIRT (Inter: κ = 0.74/0.64; wκ = 0.86/0.82; Intra: κ = 0.68; wκ = 0.84). The backward elimination model revealed NIRT to be significantly more reliable than DBW radiography., Conclusions: This study revealed a good to excellent inter- and intraexaminer reliability for proximal caries detection using DBW and NIRT images. The logistic regression analysis revealed significantly better reliability for NIRT. Additionally, the first evaluation cycle was more reliable according to the reference diagnoses.

The difference between carious lesion diagnosis and carious lesion detection is discussed here. Concerning carious lesions, 3 diagnostic requirements should be fulfilled: to detect lesions, to assess surface integrity, and to assess lesion activity to support clinical decision making. The first and most important diagnostic method is meticulous visual-tactile inspection. This is the only method that potentially contributes to all 3 diagnostic requirements. All other methods that are presented in this chapter, i.e., bitewing radiography, fluorescence-based technologies, and transillumination methods, are limited to assessing lesion depth in surfaces that are not visible to the eye and thus contribute to lesion detection only. At the end of the chapter, recent developments in objective lesion activity assessment are presented., (© 2018 S. Karger AG, Basel.)

The oral health habits of pupils had not yet been analyzed for the canton of Neuchâtel. A questionnaire was provided to 9th grade high school pupils (final year) of the three schools located in the Neuchâtel area to asses both oral health knowledge and habits in this connection. The average age was 15.5±0.8 years, and 78.1% of the questionnaires were returned. The prophylaxis program was conducted for a total of 4.5 h during pupils’ entire time at school. The results showed that both knowledge and oral health habits could be improved. As a positive outcome, 99% of the pupils brush their teeth before going to bed. Comparisons with similar 10-year-old studies from other cantons (Bern, Vaud) showed major differences in knowledge, for example on the importance of fluoridation. Only 54% of the pupils in Neuchâtel knew that fluoride offers some protection against caries, in spite of the fact that 89% thought that brushing with fluoridated toothpaste protects against caries. Most of the pupils used a fluoridated toothpaste. Furthermore, we found that self-reported sugar consumption was correlated with caries experience, but brushing frequency was not. We recommend introducing a review course for pupils in their last school year, in order to practice interdental cleaning, redefine appropriate, tooth-friendly snacks, and emphasize the importance of regular dental check-ups.

White spot lesion (WSL) infiltration has been recommended immediately after debonding of orthodontic brackets. It is however not clear if established inactive WSLs can also be masked through infiltration. Orthodontic treatment of a 19-year-old patient had to be terminated prematurely due to development of multiple WSLs of varying severity. Three months after debonding, the patient presented for lesion infiltration. After etching with 15% HCl gel and re-wetting of the dried surfaces it seemed that a good outcome could be expected. Lesion infiltration led to complete masking of less severe WSLs. The visual appearance of moderate and severe WSLs was improved but they were still visible after treatment. Inactive WSLs may not represent an increased caries risk, but patients are often bothered esthetically. Infiltration by repeated etching might be a viable approach even for inactive WSLs. Controlled clinical trials are needed to investigate the long-term performance of this technique.

This study compared the efficiency of air abrasion on enamel caries with selective enamel powder (SEP) or with alumina powder and a negative and positive control group. Ninety-three extracted molars with non-cavitated incipient enamel lesions were selected. After embedding the roots in resin, each lesion was sectioned perpendicular to the surface and photographed. Each lesion was classified microscopically as having or not having dentin involvement. The lesions were distributed into four groups with an equal number of enamel caries with or without dentin involvement. Each group was treated differently: Group 1 had SEP abrasion, Group 2 had alumina abrasion, Group 3 had sodium bicarbonate abrasion (negative control) and Group 4 had bur treatment (positive control). The surface was rephotographed after treatment. Superimposition of the photographs identified areas of "correct-excavation," "under-excavation" and "over-excavation." There were no statistical differences between lesions treated with or without dentin involvement for Groups 2 through 4. However, in the SEP group, all measured areas were significantly influenced by dentin involvement. In pairwise comparisons, no statistical differences were found between the alumina and bur groups. The SEP group, however, showed statistically significant differences for each area compared to the alumina group in enamel caries without dentin involvement. SEP performed as well as alumina and bur in lesions with dentin involvement. SEP is different in its ablative properties toward caries with dentin involvement or no dentin involvement. In terms of dental treatment, SEP seems to have a diagnostic potential for enamel lesions before operative intervention in patients with high caries risk.

This study evaluated the performance of the DIAGNOdent pen laser fluorescence device (LFpen) in comparison with visual examination (VE), bitewing radiographs (BW) and visual examination combined with bitewing radiographs (VEBW) in detecting secondary approximal caries associated with composite restorations. In total, 60 approximal surfaces from 43 permanent molars with composite restorations were assessed twice by two examiners using the LFpen, VE, BW and VEBW. After histological preparation and hardness measurements, the sample was assigned to either a crown or root caries group, depending on the location of the lesions as the gold standard. For crown caries at D1, the highest values of specificity and sensitivity were observed for the LFpen at a cutoff value of 18 (1.00) and for the VEBW (0.89). At D3 (cutoff of 30), the LFpen showed the highest values of sensitivity and specificity. For root caries, the LFpen and VEBW showed the highest values of specificity (0.54), sensitivity (0.81) and accuracy (0.69). The Spearman rank correlation coefficients for crown/root caries with histology were 0.54/0.37 (LFpen), 0.29/0.10 (BW), 0.29/0.18 (VE) and 0.23/0.37 (VEBW). For the LFpen, the ICC varied from 0.80 (interexaminer) to 0.97 (intraexaminer B); the kappa value was 0.19 for BW and 0.35 for VE (interexaminer). Intraexaminer kappa values for BW were 0.25 (A) and 0.29 (B), and those for VE were 0.31 (A) and 0.32 (B). The LFpen device exhibited a performance comparable to that of conventional methods but with higher interexaminer reproducibility. Therefore, the LFpen should be considered an auxiliary method for the detection of secondary approximal caries associated with composite restorations.

Dental products with casein phosphopeptide--amorphous calcium phosphate-nanocomplexes (CPP-ACP) are used in several tooth products (toothpastes, chewing gums, mouthrinses) and are as well used in dental filling material. CPP-ACP containing products are supposed to enhance remineralisation of dental hard tissues und thus might play a major role in prevention and therapy of initial caries or erosively dissolved enamel. Furthermore, also in hypersensitive teeth and even cases of hyposalivation, CPP-ACP containig products are supposed to improve the clinical condition. This article aims at three goals: point out the evolvement of CPP-ACP out of milk casein; description of possible biochemical effects of CPP-ACP on dental hard tissues; critical review of the current literature.

This review deals with and discusses the history and objectives of milk fluoridation from its early beginnings in Winterthur/Switzerland up to current, WHO-sponsored controlled clinical trials with some 10000 children in several developing and emerging countries as well as in Great Britain. Today the fluoridation of milk in Switzerland does not represent an alternative to the fluoridation of salt and therefore has no practical meaning in this country.