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Minimal intervention dentistry is now accepted as the contemporary approach for caries management. The development of adjunctive technologies to assist early lesion detection has led to widespread marketing of various devices over the past two decades. A thorough understanding of the clinical relevance and limitations of such devices is required to make valid interpretation of their results. This paper will discuss the most common commercially available carious lesion detection technologies in order to give dental practitioners clear information about the devices' scientific principles, advantages and limitations within a clinical context.

International audience; Objectives - A national questionnaire study was performed to document knowledge and opinions of French dental students (FDSs) about minimal intervention (MI) in dentistry especially caries risk assessment (CRA) and dental sealants (DSs). Materials and methods - A questionnaire was administered to the fifth-year dental FDSs (n = 1370) from the 16 French dental schools. Descriptive and statistical analyses were performed. Results - The response rate was 84.5%. A large majority of respondents (87.8%) linked MI with minimally invasive dentistry and 77.4% considered MI as a concept based on prevention. About 80% stated they use CRA in clinical practice, mostly without any specific form. If 80.4% of the respondents would base their treatment plans on CRA, only 55.1% would regularly plan preventive regimens according to individual risk level. However, while 96.6% declared they perform preventive DSs, only 44.3% considered therapeutic sealants as a routine treatment. Although 75.1% of FDSs stated that they had sufficient learning and training related to CRA, 55.9% thought that they need further education about preventive and therapeutic DSs. Conclusion - Although FDSs seem to be aware of the importance of CRA and preventive strategies, this study shows the need to harmonize the teaching in cariology according to the latest European recommendations. Clinical relevance - A national questionnaire study showed variability towards knowledge and opinions of FDSs related to MI in cariology. This may impact care provisions in their future professional life showing the urgent need to harmonize the teaching of MI in cariology in France.

International audience

Methanogen cultures require hydrogen produced by fermentative bacteria such asBacteroides thetaiotaomicron(biological method). We developed an alternative method for hydrogen production using iron filings and acetic acid with the aim of cultivating methanogens more efficiently and more quickly (chemical method). We developed this new method with a reference strain ofMethanobrevibacter oralis, compared the method to the biological reference method with a reference strain ofMethanobrevibacter smithiiand finally applied the method to 50 saliva samples. Methanogen colonies counted using ImageJ software were identified using epifluorescence optical microscopy, real-time PCR and PCR sequencing. For cultures containing the pure strains ofM. oralisandM. smithii, colonies appeared three days postinoculation with the chemical method versus nine days with the biological method. The average number ofM. smithiicolonies was significantly higher with the chemical method than with the biological method. There was no difference in the delay of observation of the first colonies in the saliva samples between the two methods. However, the average number of colonies was significantly higher when using the biological method than when using the chemical method at six days and nine days postinoculation (Student’s test, p = 0.005 and p = 0.04, respectively). The chemical method made it possible to isolate four strains ofM. oralisand three strains ofM. smithiifrom the 50 saliva samples. Establishing the chemical method will ease the routine isolation and culture of methanogens.

Aim Modern clinical caries management involves early stage caries diagnosis and should fit with dental health policy. The objective of this study was to achieve early caries detection in enamel and dentine with a laser-based system (DIAGNOdent™ pen) first and secondary with a new fluorescence intra-oral camera (Soprolife®). A visual inspection with a loupe was used as control. Materials and methods Following the consolidated standards of reporting trials recommendations, 628 occlusal fissures were included for analysis. Results The sensitivity and specificity of both devices varied depending on the cutoff threshold of the caries score, and the ROC curve showed higher values for the Soprolife® than for DIAGNOdent™ pen. The values of the area under the curve decreased from 0.81 (Soprolife® in daylight) to 0.79 (Soprolife® in fluorescent mode) and 0.67 for DIAGNOdent™ pen. DIAGNOdent™ pen reproducibility (intra and inter-investigator) showed a wide dispersion, with many values scattered beyond the confidence limits (±2 SD), and the weighted kappa coefficient, which was quite low (0.58), confirmed this tendency. Conclusion Caries prevalence in terms of public health policy is of interest and caries detection increased significantly when using an fluorescence-based intra-oral camera. Clinical significance The clinical significance of these findings is that fluorescence could help improve caries diagnosis, reduce clinical misinterpretations, and finally benefit the patients. How to cite this article: Terrer E, Slimani A, Giraudeau N, et al. Performance of Fluorescence-based Systems in Early Caries Detection: A Public Health Issue. J Contemp Dent Pract 2019;20(10):1126-1132.

International audience; Trichomonas tenax, an anaerobic protist difficult to cultivate with an unreliable molecular identification, has been suspected of involvement in periodontitis, a multifactorial inflamma-tory dental disease affecting the soft tissue and bone of periodontium. A cohort of 106 peri-odontitis patients classified by stages of severity and 85 healthy adult control patients was constituted. An efficient culture protocol, a new identification tool by real-time qPCR of T. tenax and a Multi-Locus Sequence Typing system (MLST) based on T. tenax NIH4 reference strain were created. Fifty-three strains of Trichomonas sp. were obtained from peri-odontal samples. 37/106 (34.90%) T. tenax from patients with periodontitis and 16/85 (18.80%˚) T. tenax from control patients were detected by culture (p = 0.018). Sixty of the 191 samples were tested positive for T. tenax by qPCR, 24/85 (28%) controls and 36/106 (34%) periodontitis patients (p = 0.089). By combining both results, 45/106 (42.5%) patients were positive by culture and/or PCR, as compared to 24/85 (28.2%) controls (p = 0.042). A link was established between the carriage in patients of Trichomonas tenax and the severity of the disease. Genotyping demonstrates the presence of strain diversity with three major different clusters and a relation between disease strains and the periodontitis severity (p

International audience; Dentin carious lesion is a dynamic process that involves de- mineralization and collagen denaturation. Collagen type I is the major protein in dentin and it has been investigated based on its optical properties. Multiphoton microscopy (MPM) is a nonlinear imaging technique that reveals the car- ies process using the collagen two-photon excitation fluo- rescence (2PEF) and its second-harmonic generation (SHG). Combining the histological and the International Caries De- tection and Assessment System (ICDAS) classifications with nonlinear optical spectroscopy (NLOS), 2PEF and SHG inten- sities of enamel and dentin were highly altered during the caries process. It has been proven that the ratio SHG/2PEF is a relevant indicator of the organic matrix denaturation [Ter- rer et al.: J Dent Res 2016;96:574–579]. In the present study, a series of measurable signals is made to detect early stages of carious lesion according to the ICDAS classification and to explore the relationship between these measures and theICDAS scale. Comparison of the efficiency of nonlinear opti- cal signals for caries detection with the ICDAS classification is essential to evaluate their potential for clinical applica- tion. In our study, the use of the NLOS measured by MPM allowed us to monitor a quantitative parameter (SHG/2PEF ratio) according to the dentin carious lesion state (ICDAS and histological examination). Three coherent new groups were defined (ICDAS 0/1; ICDAS 2/3; ICDAS 4/5/6), where the carious process can be clearly described with a statistically significant decrease of the SHG/2PEF ratio.

International audience; The oral fluid microbiome comprises an important bacterial diversity, yet the presence of archaea has not been reported so far. In order to quest for the presence of methanogenic archaea (methanogens) in oral fluid, we used a polyphasic approach including PCR-sequencing detection, microscopic observation by fluorescence in-situ hybridization, isolation and culture, molecular identification and genotyping of methanogens in 200 oral fluid specimens. In the presence of negative controls, 64/200 (32%) prospectively analysed oral fluid specimens were PCR-positive for methanogens, all identified as Methanobrevibacter oralis by sequencing. Further, fluorescence in-situ hybridization detected methanogens in 19/48 (39.6%) investigated specimens; with morphology suggesting M. oralis in 10 cases and co-infecting Methanobrevibacter smithii in nine cases. M. oralis was cultured from 46/64 (71.8%) PCR-positive specimens and none of PCR-negative specimens; and one M. smithii isolate was co-cultured with M. oralis in one specimen. Multispacer Sequence Typing found one M. oralis genotype per specimen and a total of five different genotypes with 19/46 (41%) of isolates all belonging to spacer-type four. Statistical analyses showed a significant correlation between the PCR-detection of methanogens in oral fluid and tobacco smoking. These data indicate that M. oralis and M. smithii are oral fluid-borne methanogens in tobacco smokers. Both methanogens could be transmitted during intimate contacts such as mother-to-child contacts and kissing.

Methanogens have already been described in periodontitis but not in peri-implantitis. Thirty peri-implantitis samples and 28 control samples were collected in 28 consenting peri-implantitis patients. PCR-sequencing of the 16S rRNA gene was used as a broad-spectrum screening method and results were further confirmed by real-time quantitative PCR targeting the mcrA genes. Results showed a methanogen community dominated by Methanobrevibacter oralis in 31/58 (51%) samples including 16/28 (57%) control samples and 15/30 (50%) peri-implantitis samples. Methanobrevibacter massiliense was detected in 5/58 (8.6%) samples including 3/28 (1%) control samples and 2/30 (6.7%) peri-implantitis samples. The prevalence of M. oralis or M. massiliense did not significantly differ in peri-implantitis and control samples (exact Fisher test, P = 0.61 and P = 0.67, respectively). Further ponderation of the methanogen load by the real-time quantitative PCR for actin human gene again indicated non-significant difference (Wilcoxon-Mann-Whitney test, P = 0.48 and P = 0.40, respectively). These data show that the prevalence of methanogens does not differ in peri-implantitis lesions and healthy sites, when individuals are their own control. These data do not allow assigning a specific pathogenic role to methanogens in peri-implantitis; methanogens rather are part of the commensal and normal flora of the oral cavity.

The separation zone between enamel and dentin [dentin–enamel junction (DEJ)] with different properties in biomechanical composition has an important role in preventing crack propagation from enamel to dentin. The understanding of the chemical structure (inorganic and organic components), physical properties, and chemical composition of the human DEJ could benefit biomimetic materials in dentistry. Spatial distribution of calcium phosphate crystallinity and the collagen crosslinks near DEJ were studied using confocal Raman microscopy and calculated by different methods. To obtain collagen crosslinking, the ratio of two peaks 1660 cm−1 over 1690 cm−1 (amide I bands) is calculated. For crystallinity, the inverse full-width at half maximum of phosphate peak at 960 cm−1, and the ratio of two Raman peaks of phosphate at 960/950 cm−1 is provided. In conclusion, the study of chemical and physical properties of DEJ provides many benefits in the biomaterial field to improve the synthesis of dental materials in respect to the natural properties of human teeth. Confocal Raman microscopy as a powerful tool provides the molecular structure to identify the changes along DEJ and can be expanded for other mineralized tissues.

International audience; Multiphoton confocal microscopy and nonlinear spectroscopy are used to investigate the caries process in dentin. Although dentin is a major calcified tissue of the teeth, its organic phase comprises type I collagen fibers. Caries drive dentin demineralization and collagen denaturation. Multiphoton microscopy is a powerful imaging technique: the biological materials are transparent to infrared frequencies and can be excited to penetration depths inaccessible to 1-photon confocal microscopy. The laser excitation greatly reduces photodamage to the sole focal region, and the signal-to-noise ratio is improved significantly. The method has been used to follow pathologic processes involving collagen fibrosis or collagen destruction based on their 2-photon excited fluorescence (2PEF) emission and second harmonic generation (SHG). Combining multiphoton imaging with nonlinear spectroscopy, we demonstrate that both 2PEF and SHG intensity of human dentin are strongly modified during the tooth caries process, and we show that the ratio between SHG and 2PEF signals is a reliable parameter to follow dental caries. The ratio of the SHG/2PEF signals measured by nonlinear optical spectroscopy provides valuable information on the caries process, specifically on the degradation of the organic matrix of dentin. The goal is to bring these nonlinear optical signals to clinical application for caries diagnosis.

Four single-cysteine variants of the intrinsically disordered C-terminal domain of the measles virus nucleoprotein (N(TAIL)) were cyanylated at cysteine and their infrared spectra in the C triple bond N stretching region were recorded both in the absence and in the presence of one of the physiological partners of N(TAIL), namely the C-terminal X domain (XD) of the viral phosphoprotein. Consistent with previous studies showing that XD triggers a disorder-to-order transition within N(TAIL), the C triple bond N stretching bands of the infrared probe were found to be significantly affected by XD, with this effect being position-dependent. When the cyanylated cysteine side chain is solvent-exposed throughout the structural transition, its changing linewidth reflects a local gain of structure. When the probe becomes partially buried due to binding, its frequency reports on the mean hydrophobicity of the microenvironment surrounding the labeled side chain of the bound form. The probe moiety is small compared to other common covalently attached spectroscopic probes, thereby minimizing possible steric hindrance/perturbation at the binding interface. These results show for the first time to our knowledge the suitability of site-specific cysteine mutagenesis followed by cyanylation and infrared spectroscopy to document structural transitions occurring within intrinsically disordered regions, with regions involved in binding and folding being identifiable at the residue level.

Aim The objective of this in vivo experiment is to propose an innovative therapeutic concept using a light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT) that is based on the imaging and autofluorescence of dental tissues. Background Processes with the aim of diagnosing carious lesions in the initial stage with optimum sensitivity and specificity employ a wide variety of technologies, but like the conventional diagnosis tools, they remain either inefficient or too subjective. Technique This experiment evaluated a fluorescence light-induced camera that illuminates tooth surfaces within an excitation radiation band of light with a wavelength of 450 nm and facilitates a high magnification image. Conclusions An analysis of 50 occlusal grooves revealed three clinical forms of enamel caries: (1) enamel caries on the surface, (2) suspicious grooves with a positive autofluorescent red signal, and (3) suspicious grooves with a neutral fluorescent dark signal. Two decision-making diagrams were proposed in accordance with international recommendations for preventive dentistry, but modified as a result of the accurate information obtained with this new LIFEDT device. Clinical Significance The lighting of suspect occlusal grooves with the SoproLife® camera enables observation of any variations in the optical properties to refine a caries diagnosis and facilitates more than a 50x magnification of occlusal groove anatomy to provide additional information on the carious potential of the tooth surface. Citation Terrer E, Koubi S, Dionne A, Weisrock G, Sarraquigne C, Mazuir A, Tassery H. A New Concept in Restorative Dentistry: Light-Induced Fluorescence Evaluator for Diagnosis and Treatment: Part 1 – Diagnosis and Treatment of Initial Occlusal Caries. J Contemp Dent Pract [Internet]. 2009 Nov; 10(6):086-094. Available from: http://www.thejcdp.com/journal/view/ volume10-issue6-terrer.

Preservation of natural tooth structure requires early detection of the carious lesion and is associated with comprehensive patient dental care. Processes aiming to detect carious lesions in the initial stage with optimum efficiency employ a variety of technologies such as magnifying loupes, transillumination, light and laser fluorescence (QLF® and DIAGNOdent® ) and autofluorescence (Soprolife® and VistaCam®), electric current/impedance (CarieScan(®) ), tomographic imaging and image processing. Most fluorescent caries detection tools can discriminate between healthy and carious dental tissue, demonstrating different levels of sensitivity and specificity. Based on the fluorescence principle, an LED camera (Soprolife® ) was developed (Sopro-Acteon, La Ciotat, France) which combined magnification, fluorescence, picture acquisition and an innovative therapeutic concept called light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT). This article is rounded off by a Soprolife® illustration about minimally or even non-invasive dental techniques, distinguishing those that preserve or reinforce the enamel and enamel-dentine structures without any preparation (MIT1- minimally invasive therapy 1) from those that require minimum preparation of the dental tissues (MIT2 - minimally invasive therapy 2) using several clinical cases as examples. MIT1 encompasses all the dental techniques aimed at disinfection, remineralizing, reversing and sealing the caries process and MIT2 involves a series of specific tools, including microburs, air abrasion devices, sonic and ultrasonic inserts and photo-activated disinfection to achieve minimal preparation of the tooth. With respect to minimally invasive treatment and prevention, the use of lasers is discussed. Furthermore, while most practices operate under a surgical model, Caries Management by Risk Assessment (CaMBRA) encourages a medical model of disease prevention and management to control the manifestation of the disease, or keep the oral environment in a state of balance between pathological and preventive factors. Early detection and diagnosis and prediction of lesion activity are of great interest and may change traditional operative procedures substantially. Fluorescence tools with high levels of magnification and observational capacity should guide clinicians towards a more preventive and minimally invasive treatment strategy.

Our aim was to determine the origin of the red fluorescence of carious dentine observed with the Soprolife® camera. We conducted in vitro studies to evaluate the origin of the red fluorescence using acids and matrix metalloproteinase (MMP) to mimic caries and methylglycoxal (MGO) to evaluate the effect of glycation reactions on the red fluorescence. In every step of these models, we detected the changes of dentin photonic response with Soprolife® in daylight mode and in treatment mode. A Raman spectroscopy analysis was performed to determine the variations of the dentin organic during the in vitro caries processes. Raman microscopy was performed to identify change in the collagen matrix of dentine. The red fluorescence observed in carious dentine using a Soprolife® camera corresponds to the brownish color observed using daylight. Demineralization using nitric acid induces a loss of the green fluorescence of dentine. The red fluorescence of carious dentine is resistant to acid treatment. Immersion of demineralized dentine in MGO induces a change of color from white to orange-red. This indicates that the Maillard reaction contributes to lesion coloration. Immersion of demineralized dentine in an MMP-1 solution followed by MGO treatment results in a similar red fluorescence. Raman microspectroscopy analysis reveals accumulation of AGE's product in red-colored dentine. Our results provide important information on the origin of the fluorescence variation of dentine observed with the Soprolife® camera. We demonstrate that the red fluorescence of carious dentine is linked to the accumulation of Advanced Glycation End products (AGE). The study provides a new biological basis for the red fluorescence of carious dentine and reinforces the importance of the Soprolife® camera in caries diagnostics.

The goals of this trial were, first, to produce a Raman mapping of decay and sound dentin samples, through accurate analysis of the Raman band spectra variations of mineral and organic components. The second goal was to confirm the correlation between the Raman signal and the signal of a fluorescent camera, by assaying the concentration of pentosidine and natural collagen fluorescent crosslink using reverse phase high-pressure liquid chromatography. The first correlation assumed a possible relationship between the signal observed with the camera and Raman spectroscopy. The second correlation assumed an association with the Maillard reaction. Absence of a correlation for this trial was that no association could be found between Raman spectra characteristics, fluorescence variation and the HPLC assay. Our results void this absence.

In clinical situations carious dentine tissues can be discriminated by most caries fluorescence detection tools, including a new fluorescence intra-oral camera. The objectives of this study were: (i) to analyze the Raman spectra of sound, carious, and demineralized dentine, (ii) to compare this spectral analysis with the fluorescence variation observed when using a fluorescence camera, and (iii) to evaluate the involvement of the Maillard reaction in the fluorescence variations. The first positive hypothesis tested was that the fluorescence of carious dentine obtained using a fluorescence camera and the Raman spectra variation were closely related. The second was that the variation of fluorescence could be linked with the Maillard reaction. Sound dentine, sound dentine demineralized in aqueous nitric acid solution, carious soft dentine, sound dentine demineralized in lactic acid solution, sound dentine demineralized in aqueous nitric acid solution and immersed in methylglycoxal solution, and sound dentine demineralized in aqueous nitric acid solution and immersed in methylglycoxal and glucose solutions, were studied using micro-Raman spectroscopy. Modifications in the band ratio of amide, phosphate, and carbonate were observed in the decayed and demineralized groups compared with the sound dentine group. The results indicate that a close relationship exists between the Maillard reaction and fluorescence variation.

A new and innovative therapeutic concept using a light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT) of dental caries based on the imaging and autofluorescence of dental tissues is proposed. The aims of this series of in vivo experiments are to compare and analyze the brightness variations of sound dentin and active and arrested carious dentin illuminated with an intraoral LED camera and to determine if this new device could be helpful in daily practice to discriminate between caries and sound dentin.A new intraoral LED camera that emits visible blue light was used in this in vivo study to illuminate and photograph 15 teeth at high magnification. The magnified images were examined using the free Image J V version 1.41 software. Four standardized rectangular areas were drawn on each picture that included both healthy and pathologic areas to analyze variations in brightness using a brightness formula: L = 0.299 Red + 0.587 Green + 0.114 Blue.Statistically significant differences in the brightness were found between active and arrested caries processes in an area of infected dentin designated Z2. Within the limitations of this in vivo study, the images created with the intraoral LED camera revealed significant variations in fluorescence between sound dentin and active and arrested caries processes.The LIFEDT concept provides a therapeutic concept based on these findings of variations in fluorescence between healthy and pathologic tissue.This concept defines a pragmatic clinical and therapeutic approach for treating active and arrested carious lesions based on the interpretation of variations of a fluorescence signal and applying the LIFEDT concept to the treatment of dentin carious lesions.

Aim A new and innovative therapeutic concept using a light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT) of dental caries based on the imaging and autofluorescence of dental tissues is proposed. The aims of this series of in vivo experiments are to compare and analyze the brightness variations of sound dentin and active and arrested carious dentin illuminated with an intraoral LED camera and to determine if this new device could be helpful in daily practice to discriminate between caries and sound dentin. Methods and Materials A new intraoral LED camera that emits visible blue light was used in this in vivo study to illuminate and photograph 15 teeth at high magnification. The magnified images were examined using the free Image J V® version 1.41 software. Four standardized rectangular areas were drawn on each picture that included both healthy and pathologic areas to analyze variations in brightness using a brightness formula: L* = 0.299 Red + 0.587 Green + 0.114 Blue. Results Statistically significant differences in the brightness were found between active and arrested caries processes in an area of infected dentin designated Z2. Within the limitations of this in vivo study, the images created with the intraoral LED camera revealed significant variations in fluorescence between sound dentin and active and arrested caries processes. Conclusions The LIFEDT concept provides a therapeutic concept based on these findings of variations in fluorescence between healthy and pathologic tissue. Clinical Significance This concept defines a pragmatic clinical and therapeutic approach for treating active and arrested carious lesions based on the interpretation of variations of a fluorescence signal and applying the LIFEDT concept to the treatment of dentin carious lesions. Citation Terrer E, Raskin A, Koubi S, Dionne A, Weisrock G, Sarraquigne C, Mazuir A, Tassery H. A New Concept in Restorative Dentistry: LIFEDT—Light-Induced Fluorescence Evaluator for Diagnosis and Treatment: Part 2 – Treatment of Dentinal Caries. J Contemp Dent Pract [Internet]. 2010 Jan; 11(1):095-102. Available from: http://www.thejcdp.com/journal/view/ volume11-issue1-terrer.

Cervical lesions are common and their prevalence appears to be increasing. This accentuation is explained by greater functional longevity of the dental organ as well as changes in modern lifestyle. We have observed in the literature several classifications of caries lesions and wear lesions. However, it should be noted the lack of clinical and visual classification of cervical lesions. The new classification proposed in this work aims to redress this lack of information. This classification of carious and non-carious cervical lesions is based on their visual clinical appearance and their histological extent. A management cycle of these lesions is also propo-sed. The point of this study is to provide a standardized method in order to uniform and improve the detection, diagnosis and overall management of cervical lesions.; Les lésions cervicales sont courantes et leur prévalence semble être en augmentation. Cette accentuation s’explique par une plus grande longévité fonctionnelle de l’organe dentaire ainsi que des changements de mode de vie moderne. Nous avons pu constater dans la littérature plusieurs classifications des lésions carieuses et des lésions d’usures. Toutefois, il est à noter un manque de classification clinique et visuelle des lésions cervicales. La nouvelle classification proposée dans ce travail a pour objectif de répondre à ce manque d’information. Cette classification des lésions cervicales carieuses et non carieuses est basée sur leur apparence visuelle clinique et leur étendue histologique. Un cycle de prise en charge de ces lésions est aussi proposé. L’intérêt est d’apporter une méthode standardisée, afin d’uniformiser et d’améliorer la détection, le diagnostic et la prise en charge globale des lésions cervicales.