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In this paper, we presents the method and procedure for collecting the Korean distant multi-channel speech and noise databases, which were designed for developing the highly accurate distant speech recognition system for indoor conversational robot applications. The speech database was collected at four different distant positions in an in-door room, which was furnished to simulate a living room acoustically, by the playback-and-recording method that uses an artificial mouth for playing the clean source speech data and three kinds of multi-channel microphone arrays for recording the distant speech data. The speech database further consists of a read speech dataset and two conversational speech datasets. Additionally, the noise database consists of 12 types of in-door noise, which were collected at a single distant position with the same approach. These speech and noise databases can be used for creating simulated noisy speech data reflecting various in-door acoustic conditions corrupted by room reverberation and additive noise.

The aim of this study was to evaluate both sucrose and fluoride concentrations and time of biofilm formation on enamel carious lesions induced by an in vitro artificial-mouth caries model. For Study 1, biofilms formed by streptococci and lactobacilli were grown on the surface of human enamel slabs and exposed to artificial saliva containing 0.50 or 0.75 ppmF (22.5 h/d) and broth containing 3 or 5% sucrose (30 min; 3x/d) over 5 d. In Study 2, biofilms were grown in the presence of 0.75 ppmF and 3% sucrose over 3 and 9 days. Counts of viable cells on biofilms, lesion depth (LD), and the integrated mineral loss (IML) on enamel specimens were assessed at the end of the tested conditions. Counts of total viable cells and L. casei were affected by sucrose and fluoride concentrations as well as by time of biofilm formation. Enamel carious lesions were shallower and IML was lower in the presence of 0.75 ppmF than in the presence of 0.50 ppmF (P<0.005). No significant effect of sucrose concentrations was found with respect to LD and IML (P>0.25). Additionally, deeper lesions and higher IML were found after 9 d of biofilm formation (P<0.005). Distinct sucrose concentrations did not affect enamel carious lesion development. The severity of enamel demineralization was reduced by the presence of the higher fluoride concentration. Additionally, an increase in the time of biofilm formation produced greater demineralization. Our results also suggest that the present model is suitable for studying aspects related to caries lesion development.

Objectives To investigate the effect of saliva substitutes on enamel erosion in vitro. Methods A total of 204 bovine enamel samples were embedded in acrylic resin and allocated to 17 groups (n = 12). The specimens were eroded in an artificial mouth (3 days; 6 × 30 s/days, flow rate: 2 ml/min) using citric acid (pH: 2.5). Immediately after the erosive attacks, saliva substitutes (12 sprays, 3 gels) were applied. Between the erosive cycles the specimens were rinsed with artificial saliva (flowrate: 0.5 ml/min). A SnCl2/AmF/NaF-containing mouthrinse was used as positive control, water spray served as negative control. Enamel loss was measured profilometrically and the data were analyzed using one-way ANOVA followed by Scheffe’s post hoc tests (p Results Four saliva substitutes increased enamel erosion, probably due to the low pH or the content of citric acid. Several saliva substitutes were able to reduce enamel erosion significantly by 60–90% (in the range of the positive control). The protective potential of these products was in the range of the positive control (reduction of enamel loss to 30% of negative control). The erosion-protective potential of these high-viscous products is probably related to their film-forming properties, leading to a mechanical protection of the surface. Conclusion Saliva substitutes containing a very low pH exhibit a distinct erosive potential, while most high-viscous products present an erosion-protective effect. It can be recommended that patients suffering from xerostomia and at high risk for dental erosion should use high-viscous saliva substitutes, but should avoid saliva substitutes with low pH or containing citric acid. Clinical significance It can be recommended that patients suffering from xerostomia and at high risk for dental erosion should use high-viscous saliva substitutes, but should avoid saliva substitutes with low pH or containing citric acid.

This work deals with the characterisation of single cane reeds used for clarinet or saxophone. Musicians perceive important differences of quality between reeds of the same brand, cut and strength. This thesis proposes new tools for reed characterisation in playing conditions.An instrumented mouthpiece is developed to enable the measurement of reed displacement and pressure difference on both sides of the reed using embedded sensors. From these signals, it is possible to estimate reed parameters of different physical models. Results reveal that the complexity of the physical model describing the reed behaviour must increase with the dynamic level.The instrumented mouthpiece is used in a measurement campaign involving 7 players and 20 reeds, quantifying the variability of the results due the musicians. Subjective tests conducted with these musicians show that reeds can be mainly described by one dimension (ease of playing or timbre). The correlations between the subjective descriptors and the measured objective parameters are studied to better understand the perceived differences between reeds, developing a predictive model of reed quality.In order to avoid the variability of the musician, an aspirating artificial mouth is developed. It uses the instrumented mouthpiece and it can be played by a musician or artificially. The comparison of the measurements made in both cases allows for the identification of the optimal working range in which the artificial mouth best reproduces the musician's playing according to intonation and playing level., Ce travail porte sur la caractérisation d'anches simples utilisées pour la clarinette ou le saxophone. Sachant que les musiciens perçoivent des différences importantes dans la qualité des anches de caractéristiques identiques (même marque, coupe et force), cette thèse propose des nouveaux outils pour la caractérisation des anches en situation de jeu.Un bec instrumenté utilisant des capteurs embarqués est développé de façon à mesurer le déplacement de l'anche et la différence de pression de part et d’autre de l'anche. À partir de ces signaux, il est possible d'estimer des paramètres d'anche associés à différents modèles physiques. Les résultats obtenus montrent que la complexité du modèle décrivant le comportement de l'anche doit augmenter avec la nuance de jeu. Le bec instrumenté est utilisé dans une campagne de mesures comportant 7 musiciens et 20 anches, et permet de quantifier la variabilité des résultats due aux musiciens. Des tests subjectifs sont réalisés avec ces mêmes musiciens, et montrent que les différences entre les anches se réduisent à une seule dimension (facilité de jeu ou timbre). Les corrélations entre les descripteurs subjectifs et les paramètres objectifs mesurés sont étudiées afin de mieux comprendre les différences perçues entre les anches, permettant le développement d'un modèle prédictif de la qualité des anches.De façon à éviter la variabilité produite par le musicien, une bouche artificielle aspirante est développée. La comparaison des mesures réalisées par la bouche artificielle et par un musicien permet d'identifier la plage de fonctionnement optimale où la bouche artificielle imite au mieux le jeu du musicien.

Background: Various materials have been used for treating dental caries. Dental caries is a disease that attacks hard tissues of the teeth. The initial phase of caries is a formation of bacterial biofilm, called as dental plaque. Dental restorative materials are expected for preventing secondary caries formation initiated by dental plaque. Initial bacterial adhesion is assumed to be an important stage of dental plaque formation. Bacteria that recognize the receptor for binding to the pellicle on tooth surface are known as initial bacterial colonies. One of the bacteria that plays a role in the early stage of dental plaque formation is Streptococcus mutans (S. mutans). Artificial mouth system (AMS) used in bacterial biofilm research on the oral cavity provides the real condition of oral cavity and continous and intermittent supply of nutrients for bacteria. Purpose: This study aimed to compare the profile of S. mutans bacterial adhesion as the primary etiologic agent for dental caries between using static method and using artificial mouth system, a dinamic. method (AMS). Method: The study was conducted at Faculty of Dentistry and Integrated Research and testing laboratory (LPPT) in Universitas Gadjah Mada from April to August 2015. Composite resin was used as the subject of this research. Twelve composite resins with a diameter of 5 mm and a width of 2 mm were divided into two groups, namely group using static method and group using dynamic method. Static method was performed by submerging the samples into a 100µl suspension of 1.5 x 10 8 CFU/ml S. mutans and 200µl BHI broth. Meanwhile AMS method was carried out by placing the samples at the AMS tube drained with 20 drops/minute of bacterial suspension and sterile aquadest. After 72 hours, five samples from each group were calculated for their biofilm mass using 1% crystal violet and read by a spectrofotometer with a wavelength of 570 nm. Meanwhile, one sample from each group was taken for its surface image using Scanning Electron Microscope (SEM). Result: The results showed that S. mutans biofilm mass in the group using static method was 0.34, while in the group using AMS method was 0.09. The results of the statistical analysis then showed that there was a significant difference (p=0.02) in the formation of bacterial biofilm mass between those groups. SEM image in the group using static method also showed that the attachment of S. mutans was more numerous and had a longer chain than in the group using AMS method. Conclusion: There is a difference in the profile of S. mutans bacterial adhesion between using AMS method and static method.

In the field of musical acoustics, instruments, such as the clarinet, are often played with the use of an artificial mouth or playing machine in order to objectively measure the playing characteristics such as sound levels, playing frequency, regime changes, etc. The purpose of this research was to study the tuning tendencies of the clarinet experimentally and compare this to the models found in literature. A clarinet was artificially blown to determine the playing frequencies for varying levels of blowing pressure and reed opening. These measurements could then be compared to computational models of the clarinet. The experimental results will be presented and compared with the theoretical values from past studies that predicted playing frequencies both analytically and computationally. Finally, suggestions for improving the models will be presented and discussed.In the field of musical acoustics, instruments, such as the clarinet, are often played with the use of an artificial mouth or playing machine in order to objectively measure the playing characteristics such as sound levels, playing frequency, regime changes, etc. The purpose of this research was to study the tuning tendencies of the clarinet experimentally and compare this to the models found in literature. A clarinet was artificially blown to determine the playing frequencies for varying levels of blowing pressure and reed opening. These measurements could then be compared to computational models of the clarinet. The experimental results will be presented and compared with the theoretical values from past studies that predicted playing frequencies both analytically and computationally. Finally, suggestions for improving the models will be presented and discussed.

Papier publié également dans : Proceedings en ligne de American Institute of Physics http://proceedings.aip.org/dbt/dbt.jsp?KEY=APCPCS&Volume=1137&Issue=1 (RN 2508; Sensory perception of the flavor release during the eating of a food piece is highly dependent upon mouth parameters. Major limitations have been reported during in vivo flavor release studies, such as marked intra- and inter-individual variability. To overcome these limitations, a chewing simulator has been developed to mimic the human mastication of food samples. The device faithfully reproduces most of the functions of the human mouth. The active cell comprises several mobile parts that can accurately reproduce shear and compression strengths and tongue functions in real-time, according to data previously collected in vivo. The mechanical functionalities of the system were validated using peanuts, with a fair agreement with the human data. Flavor release can be monitored on-line using either API-MS or chemical sensors, or off-line using HPLC for non-volatile compounds. Couplings to API-MS detectors have shown differences in the kinetics of flavor release, as a function of the food sample composition. Data were also collected for the analysis of taste compounds released during the human chewing but are not available yet for the chewing simulator.

The authors want to thank O. François (University of Auvergne) for his involvement in the development of the AM2 apparatus and in preparing the figures; and P. Riordan for English revision; Developing masticatory apparatus, chewing robots or an artificial mouth is an old but ever more important goal in food science, nutrition or dental research fields, as reflected by the number of existing digital or biomechanical systems. Whatever the objective of the approach, basic knowledge of the physiology of mastication, adaptation and neurophysiological control is absolutely needed before conceiving an apparatus. Obviously, the final step in the development of a mastication simulator is its validation before performing food or food bolus characterization. This validation step is imperative to avoid biased interpretation and can be performed through in vivo–in vitro comparison of particle size distributions in food boluses obtained after normal mastication. This kind of validated machine offers the chance to produce boluses for other related uses such as nutrient bioaccessibility or digestion studies, for example. Such an apparatus can also be employed to simulate different dental states or ageing conditions

In the context of a simplified model of the clarinet in which the losses are assumed to be frequency independent the analytic expressions of the various thresholds have been calculated in a previous paper [Dalmont et al., J. Acoust. Soc. Am. 118, 32.94-3305 (2005)]. The present work is a quantitative comparison between "theoretical" values of the thresholds and their experimental values measured by using an artificial mouth. It is shown that the "Raman" model, providing that nonlinear losses are taken into account, is reliable and able to predict the values of thresholds.

Objective The study aimed to evaluate the erosive effects of acids flowing with different velocities and duration on dentin previously pre-treated with distilled water or human saliva. Methods Bovine dentin surfaces were submitted to a 10 min demineralisation with hydrochloric or citric acid (pH 2.3, 37 °C) in an artificial mouth at flow rates of 3, 2.25, 1.5, 0.75 or 0.15 ml/min or in 30 ml of the respective acid without movement (each subgroup n = 16 specimens). Prior to the demineralisation, half of the specimens of each group were either pre-treated with distilled water or human saliva for 120 min. After 2, 5 and 10 min demineralisation, profilometric traces of dentin loss were performed perpendicular to the direction of acid flow at three sites (A–C) with intervals of 500 μm. The first profile (A) was taken in a distance of 1.5 mm from the acid starting to flow over the sample. Thus, median dentin loss at each site was calculated and statistically analysed by five-way ANOVA. Results Dentin loss increased with increasing acid flow rate and demineralisation time and was higher for demineralisation with citric acid compared to hydrochloric acid. For given flow rates of 0.15 to 3 ml/min, measurement of dentin loss yielded highest values for site A and decreasing values for sites B and C. For all groups, no significant differences of dentin loss were observed between specimens pre-treated with distilled water or human saliva. Conclusion Under the conditions of this study, both duration of demineralisation and acid flow rate but not pre-treatment with distilled water or saliva influence the extent of dentin erosion.

Objective To evaluate the fracture resistance of two-piece zirconia oral implants after long-term thermomechanical cycling in an aqueous environment. Non-loaded samples and a one-piece implant system served as control groups. Methods A total of 48 zirconia implants were evaluated: 16 one-piece implants (ATZ; Group A) and 32 differently connected two-piece implants (16 screwed, Group B; 16 bonded, Group C) made of Y-TZP-A (implant+abutment; B) and Y-TZP-A/ATZ (implant/abutment; C), respectively. These groups were divided into two subgroups composed of 8 samples. The samples of subgroups 1 (A1, B1, C1) were not exposed to any cyclic loading, whereas subgroups 2 (A2, B2, C2) were loaded with 10 million cycles (98 N). Subsequently, all 48 implants were statically loaded to fracture. Results A constant load on distinct lever arms resulted in different exerted bending moments during the dynamic loading (A2: 23.4 Ncm, B2: 17.9 Ncm, C2: 32.3 Ncm). All implants survived the long-term thermomechanical cycling. For the static loading the following average bending moments were calculated: A1/A2: 362/399 Ncm; B1/B2: 398/346 Ncm; C1/C2: 380/252 Ncm. Foregoing dynamic loading significantly increased fracture resistance of Group A implants, whereas Group B/C implants showed significantly decreased values. Potentially owed to the experimental setup in an aqueous environment of 60 °C, 5/8 C2 samples showed mobility between implant and abutment due to debonding after dynamic loading conditions. Significance The evaluated ceramic implant systems seem to be able to resist physiological chewing forces long-term. Within the limitations of the experimental setup, the connecting mechanism of Group C implants might be a weak point.

The aim of this study was to determine the influence of particle size, particle material and morphology on the sliding wear of 19 light curing, commercially available composites (Durafill VS, Metafil CX, Heliomolar RO, Solitaire, Arabesk, Artglass, Charisma F, Pertac II, Charisma, Degufill Ultra, TPH Spectrum, Z100, Tetric classic, Pertac Hybrid, Estilux Hybrid, Dyract AP, Compoglass F, Compoglass and Hytac).The materials were applied to an aluminum sample holder (7.5 mm diameter, 2 mm depth) in one layer and polymerized in a Dentacolor XS light curing unit for 180 s. The surface was ground flat (#1000) to remove any matrix rich surface layer. Then samples were stored in Ringer's solution for 24 h at 37 degrees C. Occlusal contact wear was simulated in a sliding wear tester (Munich Artificial Mouth). Eight specimens of each material were tested in a pin-on-block design with oscillating sliding of a Degussit antagonist (5 mm diameter) at a vertical load of 50 N. The horizontal excursion of the antagonist was 8 mm. Wear was quantified by a replica technique every 6000, 10,000, 30,000 and 50,000 cycles using a 3D-laser scanner. The materials were compared by their mean wear after 50,000 cycles. Comparisons of different composites and compomers were performed using analysis of variance and t-tests including the Bonferroni correction.The microfiller composites (Durafill VS, Metafil CX, Heliomolar RO) revealed the lowest, and the compomers (Dyract AP, Compoglass F, Compoglass and Hytac) showed the highest contact wear (p0.05). The wear of the hybrid composite (Estilux Hybrid) and the micro hybrid composites (Solitaire, Arabesk, Artglass, Charisma F, Pertac II, Charisma, Degufill Ultra, TPH Spectrum, Z100, Tetric classic, Pertac Hybrid) was higher than that of the microfiller composites (p0.05). The results showed additional significant differences within the three groups of composites. The coefficient of determination between loss of height and maximum particle size was r2 = 0.41.Both particle size and morphology have a high influence on the wear properties concerning the two-body wear in the occlusal contact area.

Summary. Objectives. Glass ionomer cements (GIC) have been modified in an attempt to improve their mechanical properties. The objective of the present paper was to compare the two-body and three-body wear of four modified GIC. The tested materials were Fuji IX (GC Corporation), Hi-Fi (Shofu) and Ketac Molar Aplicap (3M/ESPE). The cermet cement Ketac Silver Maxicap (3M/ESPE) was used as reference material. Methods. Two-body wear tests were carried out in the computer controlled ‘artificial mouth’ of the Munich Dental School, three-body wear was tested with the ACTA wear machine. Results. The resulting average two-body wear rates (in µm) were: Fuji IX 327 (SD ± 82)

Complete removal of failed posterior resin composite fillings is time-expensive and involves the risk of removing sound tooth substance. In any case of failure within the composite material, intra-oral repair would be favourable. This in vitro study was conducted to examine the effect of different preparation and bonding modes on integrity of repaired restorations. Forty-eight direct Class II resin composite restorations (Syntac Classic/Tetric Ceram) were placed in extracted human third molars. The specimens were stored for 365 days and then replaced partially by removing the central part of the proximal box with all margins located in composite. The partial repairs were placed with the same materials after pre-treatment with a silicon carbide bur and Syntac Classic (n = 8). Preparation modes have been (i) box-only parallel, (ii) box-only with undercuts, (iii) box with undercuts and additional occlusal retention. The repairs were performed either with (i) Tetric Ceram or with (ii) Tetric Flow as thin lining covered with Tetric Ceram. Before and after thermomechanical loading (100 000 cycles of 50 N and 2500 cycles between +5 and +55 degrees C in an artificial mouth), marginal quality between aged and freshly applied composite was evaluated by SEM at x200 magnification and microleakage was observed by light microscopy at x50 magnification. Box-only preparations exhibited a better fatigue resistance than preparations with additional occlusal retention. This observation was independent from the presence of undercuts (P < 0.05). An intermediary layer of flowable resin composite tended to result in better marginal quality, however, not being statistically significant.

Objective: Aspects of an Artificial Mouth System (AMS) to model the caries process in bovine enamel biofilm induced white spot enamel lesions (WSEL) were analyzed. Methods: Square shaped and polished bovine enamel slabs were covered with modeling wax and 2.5 mm diameter window was prepared to expose enamel surface at the center of each slab. Artificial biofilms were grown inside an AMS on the slabs using freshly cultured S. mutans (MT8148) in suspended in phosphate buffered saline (PBS), heart infusion (HI) with 1% sucrose and PBS for 20, 30 and 40 hrs at 37°C. The severity of demineralization was quantified by Quantitative Light-induced Fluorescence (QLF, Inspektor, Netherlands). All experiments were repeated three times (n=5 for each group). Results: A circular WSEL could clearly be detected at the center of each slab by naked eyes, which was prominent after dehydration by mild air drying. QLF data showed that severity of demineralization occurred with the increase of time interval, after 40 hours both ΔF (23+/-2.9) and ΔQ (148.75+/- 26.78) were significantly more compared to ΔF (10.14+/-2.3) and ΔQ (47.63+/-30.67) of 20 hours. Conclusion: An advanced in vitro model of biolfilm induced WSEL was developed that showed promises to be useful in studying enamel demineralization. DOI: http://dx.doi.org/10.3329/cdcj.v9i1.11829 City Dental College Journal Vol.9(1) 2012 4-6

A vacuumed artificial mouth has been assembled and tested to measure reed velocity for a Bb clarinet along the width of the reed. Reed velocity measurements may be useful for better estimation of parameters in physical models, such as the relevant surface area of the vibrating reed. Use of a vacuum system instead of a pressurized mouth chamber allows straightforward observation and manipulation of the mouthpiece apparatus. Point measurements of reed velocity were obtained via a laser-Doppler vibrometer directed at the reed surface when artificially blown. Simultaneous high-speed exposures were recorded to visualize reed motion. Preliminary results indicate that the velocity amplitude of any torsional motion in the reed is negligible compared to an asymmetric reed velocity, likely caused by natural limitations of the clarinet ligature. Velocity measurements also indicate that the reed may sometimes rebound against the mouthpiece in its oscillatory period. High-speed exposures support this conclusion by vis...

The release of aroma compounds from rehydrated French beans in an artificial mouth system and in the mouths of 12 assessors was studied by gas chromatography combined with flame ionisation detection and sniffing port detection. In an artificial mouth system, volatile compounds were isolated under mouth conditions, such as temperature, salivation, and mastication. No significant differences were determined between the aroma release from the beans in the artificial mouth and release in the mouths of assessors. However, both the real and artificial mouth systems differed significantly from a purge-and-trap and a dynamic headspace system in aroma release. In order to study aroma release over time, volatile compounds were isolated from rehydrated French beans for 1, 1.5, 3 and 12 min in the artificial mouth system and analysed by gas chromatography/sniffing port analysis. 2-Methylpropanal, 2-/3-methylbutanal, hexanal, 2-methyl-2-butenal, 1-octen-3-one, and dimethyl trisulphide possessed detectable odours when isolated from the French beans in the artificial mouth for all time periods. The odour active compounds 2-/3-methylbutanal and hexanal were shown to be released at a constant rate. Different sampling times resulted in identical selections of aroma compounds, while mutual proportions were retained.

The in vitro marginal fit of five different all-ceramic crown systems (In-Ceram, Empress staining technique, Empress veneering technique, Celay feldspathic system, Celay In-Ceram system) was evaluated before and after cyclic preloading in an artificial mouth. The crowns were adhesively luted to extracted natural maxillary incisors prepared with a 90 degrees shoulder. The results were compared to those for porcelain-fused-to-metal (PFM) crowns with circular porcelain-butt margins which were cemented with zinc phosphate cement. The analysis of the marginal discrepancies showed significant (P < 0.001) differences among the groups. Crown cementation increased the marginal gaps significantly (P < 0.01). Empress staining technique crowns showed the smallest marginal gaps (median 47 microm), followed by conventional In-Ceram crowns (median 60 microm) and Empress veneer technique crowns (median 62 microm). Celay In-Ceram crowns displayed marginal openings with a median of 78 microm, followed by Celay feldspathic crowns with a median of 99 microm. The marginal gap of the PFM control crowns showed a median of 64 microm. Ageing in the chewing simulator had no significant influence on the marginal fit of all specimens. The study indicates that all the tested all-ceramic crowns have clinically acceptable margins. However, in vivo investigations of all all-ceramic crown systems should be made before clinical routine.

A new and original statistical approach was used to compare the effectiveness of 4 different methods to analyse aroma compounds of seven different commercial semi-hard cheeses with regard to their orthonasal sensory perception. Four extraction methods were evaluated: Purge and Trap, Artificial Mouth, Solid-Phase Microextraction (SPME) and Solvent-Assisted Flavour Evaporation (SAFE). Among the headspace methods, Artificial Mouth gave the closest representation of the studied product space to the sensory perception one. The SAFE method was complementary to the dynamic headspace methods, as it was very efficient in extracting the heavy molecules but less efficient for extracting the most volatile compounds. SPME and Purge and Trap gave intermediate representations. At the product level, results indicate that carboxylic acids are present in similar amounts in the different commercial marks of semi-hard cheeses, that esters and aldehydes vary in small proportions and that the proportions of sulphur compounds, alcohols and ketones mainly explain the sensory differences between the commercial marks.

OBJECTIVE This in vitro study aimed to investigate the preventive effect of brushing with anti-erosive toothpastes compared to a conventional fluoride toothpaste on dentine erosion. MATERIALS AND METHODS Bovine dentine specimens (n=12 per subgroup) were eroded in an artificial mouth (6 days, 6×30 s/day) using either citric acid (pH:2.5) or a hydrochloric acid/pepsin solution (pH:1.6), simulating extrinsic or intrinsic erosive conditions, respectively. In between, the specimens were rinsed with artificial saliva. Twice daily, the specimens were brushed for 15 s in an automatic brushing machine at 2.5 N with a conventional fluoride toothpaste slurry (elmex, AmF) or toothpaste slurries with anti-erosive formulations: Apacare (NaF/1% nHAP), Biorepair (ZnCO3-HAP), Chitodent (Chitosan), elmex Erosionsschutz (NaF/AmF/SnCl2/Chitosan), mirasensitive hap (NaF/30% HAP), Sensodyne Proschmelz (NaF/KNO3). Unbrushed specimens served as control. Dentine loss was measured profilometrically and statistically analysed using two-way and one-way ANOVA followed by Scheffe's post hoc tests. RDA-values of all toothpastes were determined, and linear mixed models were applied to analyse the influence of toothpaste abrasivity on dentine wear (p

cote interne IRCAM: Lopes13a; None / None; National audience; This paper deals with a robotized arti?cial mouth adapted to brass instruments. A technical description of the robotic platform is drawn, including calibrations, initialization processes, and modes of control. An experimental protocol is proposed and the repeatability is checked. Then, experiments are conducted on a trombone for several types of quasi-static controls. Sound descriptors (fundamental frequency, roughness, energy) of measured acoustic signals are estimated and used to build cartographies indexed by the control inputs. An analysis reveals that several stable notes can easily be reached using a basic mapping with respect to these control inputs. However, the histogram of fundamental frequencies shows that input impedance peaks in the high range of the instrument do not correspond to notes that can be played by the arti?cial mouth, contrarily to musicians. It also reveals that some notes are dif?cult to play in the middle range. This exploration suggests some possible improvements of the machine that are ?nally discussed.

The two-body and three-body wear of glass-ionomers (GIC), visible light cured glass-ionomers (VLC-GIC), and composites were compared. The wear simulations were performed for the two-body wear in an artificial mouth and for the three-body wear with the so-called ACTA machine. The tested materials were different conventional glass-ionomers, light cured glass-ionomers, composites, and amalgam. The wear rates of 8 specimens of each material for the two-body and 16 for the three-body wear test were compared. After 10(5) cycles with each testing device, the wear shapes were measured. All measurements were related to the wear rate of amalgam. For the two-body wear method, the worn materials were qualitatively judged by scanning electron microscopy. The two different wear testing methods lead to similar results with slight differences in ranking. Amalgam showed the lowest wear rates with both methods. Photac Fil, a newly developed VLC-GIC, showed dramatically lower wear resistance than composites and conventional GIC with both methods. Further investigations are necessary to identify the material-specific parameters influencing the wear behaviour of a material in relation to different wear testing methods.

The impact of odour on taste has been widely studied and it is less the case for aroma and texture perceptions. The relations between odour and texture notably are not very clear and results from previous works are not in accordance. Furthermore, there is little information on the impact of an odour, representative of an aroma released in human mouth, presented via the orthonasal route on other perceptions. Most of the time, investigations dealing with sensory interactions were carried out on food model matrices which lead to a problem for extrapolation of the results to real food products. The aim of the study was to measure the impact of an odorant flow on aroma, taste and texture perceptions when eating a complex real food. To fulfill the objective, apple was chosen as a complex and familiar real food matrix and an innovative device, called ‘Mouth to Nose Merging System’ was designed, validated and used in this work. It involved (1) an in vitro chewing simulator called ‘artificial mouth’ and delivering an odorant extract similar to the aroma released in human mouth; (2) in vivo olfactory receptors of a judge’s nose, from a trained panel. The study showed that apple texture perception can be modified by the apple odorant extract. The latter did not modify aroma and taste perception. The method gave promising results for investigating cognitive interactions resulting from food consumption as odour and texture interactions were underlined.

The city of Saint-Louis is marked by recurrent floods, despite the decrease in rainfall. The town that grew downstream the vast plain where Senegalese-Mauritanian basin topography flattens considerably has experienced periodic flooding since its foundation. In 2003, the premature flooding of the Senegal River urged the Senegalese authorities to take the initiative to open a breach in the coastal sand strip of the “Langue de Barbarie,” in order to evacuate the water surplus from the river to the ocean and therefore resolve forever the problem of river flooding. But the disruption of estuarine dynamics has led to a rapid expansion of this gap: a few meters wide at its excavation, it reaches over 2,700 m in August 2009. Moreover, 10 months after the widening of the gap, the old river mouth was completely closed. If the natural movement of a mouth can be observed on some major deltas in the world (even on the Senegal River in the past), this is here a true man-made relocation. Based on the statistical analysis of series of hydrological data, this article demonstrates on the one hand that climatic conditions in 2003 which generated a major flood is an anomaly detected in the sequence of dry climate variability observed in the Sahel. On the other hand, it studies the rapid evolution of this new mouth of the Senegal River and discusses some of impacts on the regional social–ecological system, in this sensitive Sahelian environment.

Bovine enamel has been a good model for human enamel across a broad range of studies. The present work sought to consider if bovine enamel would be a suitable substitute for human enamel in experiments on simulated oral lubrication. Enamel samples of the same size were prepared from bovine and human teeth for use as maxillary and mandibular elements in a miniature artificial mouth. Sliding speeds from 1.99 to 7.84 mm/s and occlusal forces of 3.8-19.5 N were used. Water and four solutions consisting of a mucin-rich fraction, a statherin-rich fraction, 3[(3-cholamidopropyl)-dimethylammonio]-1-propanesulphonate and sodium dodecyl sulphate were evaluated. The high correlations between widely different lubricants on the two enamel substrates gives confidence in the use of bovine enamel as a model for human enamel in salivary lubrication studies. Knoop hardness indentations on enamel samples were combined with friction data and calculations of the true contact area to give a method for the indirect determination of surface shear. The calculated surface shear value was compared with published values obtained by punch shear testing.

The release of mercury vapor from class I amalgam restorations prepared in human molar teeth was studied during chewing simulations in an artificial mouth of a bi-axial servo-hydraulic mechanical test system. So that the total mercury released from the restoration over a fixed time could be determined, a closed chamber surrounded the envelope of chewing motion. In addition, the influence of sampling frequency on mercury release was corrected by the use of different sampling frequencies over a fixed time interval of mercury release measurement and extrapolation to zero sampling time. Thus, a combination of a closed environment and an extrapolation method to determine the mercury release under continuous sampling was used to determine the mercury released under normal breathing conditions. The measured mercury release rate data were used to calculate the potential daily mercury dose in a patient due to a single amalgam restoration, following the method previously outlined by Berglund. The mercury release from both a conventional and a high-copper amalgam was evaluated at different age intervals after the restoration was placed in the teeth. The results show that while the age of the amalgam and the amalgam type influence the extent of mercury release during the initial non-steady-state conditions, the steady-state value of mercury daily dose due to a single amalgam filling is 0.03 ug/day, which is well below the calculated threshold-limiting value (TLV) of 82.29 μg/day considered dangerous for occupational exposure in the United States.

A method for analysing the flavour release from chewed food has been developed. Flavour release is studied in an artificial mouth simulating the process of chewing and using fluid model systems, in our case aromatised oil in water emulsions. The fast transfer of volatile substances from the chewpulp into the gaseous phase is followed up by comparing six quickly taken gas samples. Volatile substances are analysed by means of a special technique which includes cryofocusing and capillary gas chromatography. As a wide spectrum of individual volatile substances is considered, systematic investigations into the flavour release from food under mouth-typical conditions are possible.

International audience; We investigate the influence of a time-varying blowing pressure on the oscillation threshold and attack transient of a clarinet. In this experimental study, a clarinet is blown through an artificial mouth, which allows the time profile of the blowing pressure to be controlled during the experiment. The chosen profile is a slowly increasing linear ramp, until a given steady value is reached. Different experiments have been carried out and analyzed. Depending on the slope of the ramp and on the steady value, but also on the opening of the reed channel at rest, the steady state (oscillating or not), the oscillation threshold and the attack transient are determined. Does the fact that the blowing pressure varies in time have a similar influence on a real clarinet as on a simplified model ? To answer this question, the experimental results are compared to the conclusions presented in a companion paper where a mixed numerical/analytical approach has been developed on a simplified clarinet model. Characteristics such as bifurcation delay and dynamic bifurcation are addressed.

The accumulation on teeth of three strains of oral bacteria, ‘Streptococcus mitior’ LPA-1, Streptococcus mutans C67-1, and Streptococcus rattus BHT, was studied from 8 to 90 hours after inoculation. Direct and viable counts demonstrated that strains BHT and C67-1 accumulated more rapidly than strain LPA-1, with fastest growth during the first 16 hours (td8-16h 3.6-4.8 h). In older cultures, S. mutans and S. rattus continued to accumulate and a high proportion of the cells were viable. In contrast, ‘S. mitior’ cultures contained many non-viable organisms, possibly due to hydrogen peroxideinduced death. When S. rattus was co-cultured with ‘S. mitior’ it was strongly inhibited during the first 24 hours, but increased in proportion after 66 and 90 hours. It was concluded that in the interaction between ‘S. mitior’ and S. rattus during initial plaque development, a potentially rapid initial growth rate was of less importance than the ability to antagonise the other organism.Keywords: Streptococcus mutans; Streptococcus rattus; ‘Streptococcus mitior’; Oral streptococci; Growth on teeth; Model mouth; Microbial interactions.

Similarly to human chewing, tasty compounds are released in saliva during the food piece mastication in the ‘Artificial Mouth’, and so, are available continuously. Glutamate is present in numerous food, as taste enhancer, has a nice and sought “umami” taste, specific receptors and different inter individual sensitivities, and is a fair marker of the release of tasty compounds. The three sensors (for pH, salt, or glutamate concentration) have the same size, so they are easily interchangeable. Up to now, only one kind of parameter may be analysed at a time by the different sensors. Nevertheless, combined electrodes may be developed in the future.

A clarinet with all toneholes closed has been artificially blown and the respective variations of mouthpiece sound pressure, reed opening, velocity of air-flow from the artificial mouth into the instrument, and the pressure in the artificial mouth have been measured. In this paper, the details of these four waveforms are studied and compared for typical examples. Important results are:(1) The reed opening is proportional to the mouth-piece pressure for periodic vibrations, except for the reed-displacement limitations.(2) For nonperiodic vibrations, both the mouthpiece pressure and the reed opening must be observed because their variations are less correlated.(3) The air-flow velocity is roughly proportional to the reed opening when the pressure in the mouthpiece is not so high; however, it decreases with further increase of the mouthpiece-pressure which widens the reed opening. So far as our experimental results are concerned, no positive evidence of the air-flow from the instrument into the artificial mouth has been found.(4) The amplitude of the reed vibrations is limited by the mouth-piece lay or by the artificial lip or by both of these in most vibratory states, while the reed displacement is not restricted in a few states. No rule was found relating the reed-displacement limitation and the blowing parameters (lip-adjustment and blowing pressure).(5) The pressure in the artificial mouth used for these experiments has been isolated from the sounding clarinet system because it has been kept almost constant.

The aim of this pilot study was to investigate the anticaries activity of a nanoemulsion composed of soybean oil, water, Triton X-100 and cetylpyridinium chloride.Tooth blocks (3 mm length x 3 mm width x 2 mm thickness) were cut from smooth surfaces of selected molar teeth using a water-cooled diamond wire saw. The blocks were randomly assigned to three experimental groups: (A) nanoemulsion, (B) 0.12% chlorhexidine gluconate, and (C) no treatment. The formation of dental caries in human tooth enamel was tested using a continuous flow dual-organism (Streptococcus mutans and Lactobacillus casei), biofilm model, which acts as an artificial mouth and simulates the biological and physiological activities observed within the oral environment. Experimental groups A and B were treated with their respective solutions once daily for 30 s on each occasion, while group C received no treatment. 10% sucrose was supplied every 6 h for 6 min to simulate meals and pH cycling. The experiment lasted for 5 days, and the tooth blocks were harvested and processed for demineralization assessment using transverse microradiography (TMR).For both lesion depth and mineral loss, statistical analysis indicated that Emulsion was significantly lower than Control and Chlorhexidine, and Chlorhexidine was significantly lower than Control.We conclude that cetylpyridinium-containing nanoemulsions appear to present a feasible means of preventing the occurrence of early caries.

In brass instruments the player's lips are used as a control valve that allows an oscillating flow of air into the instrument. The behaviour of this valve, the lip-reed, is determined by both the pressure difference across the lips and the open area between the lips. Computer simulations of brass instrument playing frequently represent the lips as an oscillating system with one degree of freedom, representing the height of the lip opening. This study aims to provide experimental evidence to determine values of an exponential coefficient q defining the area-height function for the lips of trombone players. A high speed digital video camera and transparent mouthpiece have been used to produce detailed images of the motion of the vibrating lips of a range of musicians and an artificial mouth over a large set of playing frequencies and sound levels. These images are analysed to investigate how the open area varies as a function of the height between the lips.

Artificial microcosm plaques were grown in a five-plaque culture system for up to 6 weeks, reaching a maximum depth of several mm. Procedures for long-term pH measurement with glass electrodes were established; they showed that the application of 5 or 10% sucrose for 6 min with a slow continuous flow of a basal medium containing mucin (BMM) generated the pH changes characteristic of in vivo Stephan curves. These pH responses were reproducible between plaques. Plaque mass and thickness were critical variables. Successive, sucrose-induced pH curves in plaques up to 4 mm thickness showed minor reductions only in the amplitude and rates of pH change. In plaques over 4 mm thick there was a pronounced reduction in pH response to successive sucrose applications, indicating increased diffusion limitations--a result of plaque growth to seal in the freshly-inserted pH electrode. In plaques of 6 mm maximum thickness, 10% sucrose induced a decrease to below pH 5.5 lasting 24 h, compared to the pH response in 2 mm thick plaque, which returned to the resting pH in 2 h. Differences in pH of up to 0.9 units were identified in thick plaques between inner and outer layers. The BMM flow rate was a critical determinant of the amplitude of the pH response to sucrose and subsequent return to resting pH. These results confirm, for microcosm plaque, the importance of clearance dynamics and diffusion-limited gradients in regulating plaque pH.

It is well established that the development of new technologies for early detection and quantitative monitoring of dental caries at its early stage could provide health and economic benefits ranging from timely preventive interventions to reduction of the time required for clinical trials of anti-caries agents. However, the new technologies currently used in clinical setting cannot assess and monitor caries using the actual mineral concentration within the lesion, while a laboratory-based microcomputed tomography (MCT) has been shown to possess this capability. Thus we envision the establishment of mathematical equations relating the measurements of each of the clinical technologies to that of MCT will enable the mineral concentration of lesions detected and assessed in clinical practice to be extrapolated from the equation, and this will facilitate preventitive care in dentistry to lower treatment cost. We utilize MCT and the two prominent clinical caries assessment devices (Quantitative Light-induced Fluorescence [QLF] and Diagnodent) to longitudinally monitor the development of caries in a continuous flow mixed-organisms biofilm model (artificial mouth), and then used the collected data to establish mathematical equation relating the measurements of each of the clinical technologies to that of MCT. A linear correlation was observed between the measurements of MicroCT and that of QLF and Diagnodent. Thus mineral density in a carious lesion detected and measured using QLF or Diagnodent can be extrapolated using the developed equation. This highlights the usefulness of MCT for monitoring the progress of an early caries being treated with therapeutic agents in clinical practice or trials.

International audience; Varying the crushing parameters in a model mouth apparatus gave different crushed apple samples, which were compared to apples crushed in the human mouth by six people. An image analysis method was developed to measure the similarity between apple particles after crushing in the artificial mouth and in the human mouth. Thus, experimental conditions were determined that produced fruit in a state closest to that obtained after mastication in a human mouth. The influence of these different conditions on the quantity of released volatile compounds was then studied.

International audience

summary This study investigated whether glass fibre-reinforced composite (FRC) specimens can benefit from post-curing using electron beam irradiation. Twenty-four frameworks of the Vectris® and 24 of the Stick glass fibre-reinforced system were veneered with their correspondent veneer materials. Eight specimens of both systems were post-cured using electron beam irradiation (3 × 33 kGy, 10 MeV). The specimens were fixed in a restrained-end apparatus and inserted in an artificial mouth. With the exception of controls (n = 8 each) all other groups were thermally cycled and mechanically loaded (TCML). Finally, all samples were loaded to fracture using a universal testing machine. In two of eight non-irradiated Vectris/Targis® specimens facing fracture occurred during TCML. Irradiation avoided these failures. No Stick®/Sinfony® facing fractured. However, Stick frameworks showed considerable torsions. Post-curing with electron beam irradiation made Stick frameworks stiffer. The fracture load of irradiated Stick®/Sinfony® specimens reached 520 ± 31 N; control (without TCML and irradiation) 396 ± 14 N, TCML-group without irradiation 362 ± 41 N. Irradiated Vectris/Targis® had a fracture resistance of 575 ± 57 N; the control 556 ± 36 N and the TCML group without irradiation 383 ± 51 N. This investigation demonstrated that different types of FRC systems could considerably benefit from electron beam irradiation. The reconstructions became stiffer and resisted higher load.

International audience; Flavour release during eating of a food depends upon many parameters that can hardly be managed. In-vivo measurements by the APCI MS-nose method allowed temporal sensory evaluation and flavour release data to be directly correlated, but several limitations have frequently been reported. These were: high inter-individual variability, low repeatability of measurements, and weak experiment throughput due to panellists' exhaustion. To overcome most of these limitations, the use of an artificial mouth for online mesurement of flavour release is recommended. However, the systems used in previous reports were limited in terms of reproducing in-vivo oral functions and parameters. This paper introduces a newly designed chewing simulator, which reproduces as realistically as possible most of the physiological functions of the human mouth. The active part of the system is a dedicated cell, precisely tooled in a biocompatible and inert material, which is 3 axes fully actuated and computer driven. The cell is composed of several mobile parts that are able to reproduce accurately in real time shear and compression strenghts and tongue functions, according to in-vivo collected data. The flavour release can be on-line monitored by either APCI-MS or chemical sensors. On-line taste sampling is under development.

Titelseiten und Inhaltsverzeichnis 1\. Einleitung und Problemstellung 7 2\. Literaturübersicht 9 3\. Ziele und Fragestellungen 49 4\. Material und Methode 53 5\. Ergebnisse 77 6\. Diskussion der Anwendung des In-vitro-Kariesmodells 97 7\. Übergreifende Diskussion 111 8\. Zusammenfassung 119 9\. Abstract 121 10\. Literaturverzeichnis 123 11\. Anhang 181, Weiter- und Neuentwicklungen von Strategien zur Kariesprävention scheinen trotz erheblicher Präventionserfolge weiterhin notwendig zu sein. In-vivo Untersuchungen stoßen dabei an ethische und tierschutzrechtliche Grenzen. Daher ist es notwendig, realitätsnahe In-vitro Modelle zu entwickeln, die den vier kariesätiologischen Hauptfaktoren Wirtsorganismus , Plaque , Substrat und Zeit Rechnung tragen und eine Einschätzung des kariespräventiven Potenzials neuer Ansätze ermöglichen. Ziel dieser Arbeit war daher die Entwicklung eines neuartigen biofilmbasierten In-vitro Kariesmodells zur Erzeugung kariesähnlicher Läsionen und die Anwendung des Modells zur Einschätzung des kariespräventiven Potenzials verschiedener, zukünftig einsetzbarer kariespräventiver Strategien, für die bislang eine realitätsnahe In-vitro-Testung fehlte. Mit Hilfe des gewählten Aufbaus war die Kultivierung eines S.-mutans-Biofilms über einen Zeitraum bis zu neun Wochen ohne Fremdkontamination möglich. Das Modell erlaubte die reproduzierbare Erzeugung initialer Primär- und Sekundärkariesläsionen im Zahnschmelz, die mit natürlich entstandenen Läsionen vergleichbar waren. Die karieshemmenden Eigenschaften etablierter Verfahren, wie der Fluoridierung und der Versiegelung von Zahnoberflächen mit Kompositmaterialien, konnten innerhalb des In-vitro- Modells reproduzierbar nachgestellt werden, und es konnte zur Untersuchung ausgewählter experimenteller kariespräventiver Maßnahmen verwendet werden. Neben etablierten Konzepten entwickeln sich auch im Bereich der Kariologie zunehmend biologische Konzepte, die darauf abzielen, die Pathogenität des oralen Biofilms abzuschwächen. Da Immunisierungen gegenüber dem Leitkeim S. mutans aufgrund der fehlenden Lebensbedrohlichkeit dieser Erkrankung wenig angemessen erscheinen, könnten Mechanismen, die einer Adhäsion dieses Keimes an der Zahnoberfläche entgegenwirken, zukünftig eine Rolle spielen. Eigene In- vitro Ergebnisse zeigten, dass von heterogen strukturierten Glykanlösungen eine die lektinvermittelte Adhäsion dieses Keimes inhibierende Wirkung ausgeht. Mit der vorliegenden Arbeit konnte gezeigt werden, dass eine experimentelle Glykanlösung mit antiadhäsiven Eigenschaften gegenüber S. mutans eine kariesprotektive Wirkung besitzt, die sich in einem Experiment an gnotobiotischen mit S. mutans infizierten Ratten verifizieren ließ. Durch den Nachweis der karieshemmenden Wirkung der Glykanlösung eröffnet sich die Perspektive einer innovativen Ergänzung der Kariesprävention auf biologischer Ebene, von der keine Nebenwirkungen oder Resistenzentwicklungen zu erwarten sind und die im Sinne eines proof of principle Einfluss auf die Behandlung von Infektionserkrankungen in anderen medizinischen Bereichen haben könnte. Aufgrund der Reproduzierbarkeit, der Sicherung des Langzeitbetriebs ohne Fremdkontamination und der Möglichkeit der Manipulierbarkeit der Proben während des laufenden Betriebs erscheint das In-vitro Modell geeignet, ein breites Spektrum an Fragestellungen zur Weiter- und Neuentwicklung kariespräventiver Strategien zu bearbeiten. Somit kann es einen Beitrag leisten, im Rahmen der Kariesforschung notwendige Tierversuche und klinische Experimente auf ein absolut notwendiges Mindestmaß zu reduzieren., Although during recent years a caries decline could be detected for most industrialized countries, dental caries remains an important problem. Therefore, continuing development of new preventive strategies and techniques still seems to be indispensable. Due to ethical considerations, the use of in- vivo human and animal studies must be restricted to the minimum. Therefore, it seems to be necessary to develop in-vitro models that allow a simulation of the four etiological factors of dental caries (host, plaque, substrate, and time) in a realistic way and hence an estimate of the caries preventive potential of new measures. The aim of the present work was to develop a novel biofilm-based caries model for the production of caries-like lesions and to evaluate the model by testing innovative strategies that might be used for the prevention of dental caries in the future. The biofilm-based in-vitro caries model allowed the continuing cultivation of a Streptococcus mutans biofilm for up to nine weeks without unintentional contamination. The model was capable of producing initial primary and secondary caries-like lesions in a reproducible way. The histopathological appearance of the lesions was comparable to naturally induced initial caries lesions. The caries-preventive potential of established measures such as application of fluoride solutions and pit and fissure sealing could be simulated reproducibly, and the model was successfully used to test a set of experimental preventive strategies. Besides established concepts, biological strategies such as immunization increasingly develop in cariology in order to reduce the pathogenicity of oral biofilms. However, caries prevention by immunization against S. mutans does not seem to represent an appropriate strategy because dental caries is not a life- threatening disease. Consequently, concepts focusing on blocking the adhesion of pathogens to the tooth surface might be of importance for future strategies. Recent studies from our laboratory showed that heterogenic- structured glycan solutions have the ability to prevent the lectin-mediated in-vitro adhesion of S. mutans. The present study revealed that an experimental glycan solution with anti-adhesive properties was able to reduce the development of caries-like lesions in-vitro and in gnotobiotic rats. These findings provide a new perspective for a biological caries preventive strategy. In terms of a proof of principle , this strategy might also have high impact on the treatment of microbial infections in other fields of medicine because neither a development of resistance nor of unwanted side effects can be expected. Because of the reproducibility, the possibility of long operation periods without unintentional contamination, and the possibility to manipulate specimens during operation, the biofilm-based in- vitro caries model seems to be appropriate for studying the outcome of a wide spectrum of new experimental preventive strategies. The model can make an important contribution to reducing necessary animal and human caries studies to the absolute minimum.

International audience; The question of what limits the amplitude of the oscillations of clarinet-like instruments is investigated. The study is based on numerical simulations in which two kind of losses are taken into account: linear losses and non-linear losses localised at the open end of the tube. The influence of the amount of losses on the saturation process and on the playing range of clarinet-like instruments is shown. Results are confirmed by experiments using an artificial mouth in which the non-linear losses are varied using several terminations with different geometries. 2004 Elsevier Ltd. All rights reserved.

The complexity of the oral environment, and ethical problems associated with studies of oral diseases in humans inevitably directed the attention to development of laboratory models, that simulate the human oral microcosm. These developments and in particular the in vitro 'artificial mouth' systems have progressed from simple and basic apparatus devised by Magitot and Miller at the end of 19th century to the currently available, highly sophisticated, computer-controlled, multi-station artificial mouth systems. These advances have metamorphosed from the early studies devised primarily to investigate factors affecting the carious process to the present designs that evaluate growth, pathogenicity, metabolism and mineralization of dental plaque under highly controlled conditions. The modern 'artificial mouth systems' can evaluate microbial interactions in simulated dental plaque and similar biofilms and monitor their physical, chemical, biological and molecular features to a very high degree of accuracy. We review and trace here the historical aspects and developments leading to the currently available artificial mouth systems and discuss their contribution to the study of oral flora, especially related to many variants of dental caries.

The objective was to investigate associations between the results of an in vitro and an in vivo study using an artificial mouth and a study of adhesive fixed partial dentures (AFPD) begun in 1985 [1]. Twenty extracted human molars and 20 human upper incisors were inserted into PMMA resin, 6 mm apart to represent a gap. Two preparation methods (identical to those in in vivo conditions) were used: a retentive preparation technique (posterior) and a non-retentive preparation technique (anterior). The frameworks of the bridges consisted of CoCr-alloy with a ceramic veneered pontic to replace the missing tooth. The bonding surfaces of the posterior AFPDs were conditioned with a tribochemical system, while the anterior AFPDs were sandblasted. All AFPDs were inserted using a dual curing composite cement. During thermal-cycling and mechanical loading (TCML: 6000 x 5 degrees C, 1.2 x 10(6) x 50 N, 1.66 Hz) in an artificial environment, the frequency and type of failures were observed. The above mentioned loading parameters were hypothesized to represent a period of 5 years under oral conditions. The results were compared to those of similar bridge-types in the in vivo study. The Kaplan-Meier estimations showed similar graphs for in vivo and in vitro with both types of AFPDs. In vivo and in vitro, the retentively prepared AFPDs were markedly more successful. With regard to the failure types, the simulation-parameters seemed to represent a loading stress that was comparable to in vivo conditions.

The manufacture of musical instruments is a domain where the know-how is primordial and rules of the profession are hard to explain and to formalise. In this article we present a new experimental approach with the aim of assisting the manufacture of musical instruments. In this perspective, we have developed an “artificial mouth” that permits to make objective tests on instruments (trumpet or trombone), overlooking the natural adaptation faculty of the musician.