1 UMR 5248 CBMN CNRS-Université Bordeaux 1-ENITAB, Laboratoire de Microbiologie et Biochimie Appliquée, 1 cours du Général de Gaulle, 33175 Gradignan Cedex, France
2 UMR 5248 CBMN CNRS-Université ...Bordeaux 1-ENITAB, Institut Européen de Chimie et Biologie, B8 avenue des facultés, F-33402 Talence Cedex, France
3 Laboratoire de Chimie des Substances Naturelles, EA 1069, FST, 123 Av. A. Thomas, 87060 Limoges, France
Several Bacillus strains isolated from commercial probiotic preparations were identified at the species level, and their adhesion capabilities to three different model intestinal surfaces (mucin, Matrigel and Caco-2 cells) were assessed. In general, adhesion of spores was higher than that of vegetative cells to the three matrices, and overall strain Bacillus cereus CH displayed the best adhesion. Different biochemical treatments revealed that surface proteins of B. cereus CH were involved in the adhesion properties of the strain. Surface-associated proteins from vegetative cells and spores of B. cereus CH were extracted and identified, and some proteins such as S-layer components, flagellin and cell-bound proteases were found to bind to mucin or fibronectin. These facts suggest that those proteins might play important roles in the interaction of this probiotic Bacillus strain within the human gastrointestinal tract.
Correspondence M. Urdaci m-urdaci{at}enitab.fr
Abbreviations: GIT, gastrointestinal tract
These authors contributed equally to this work.
This clinical report describes the use of modern CAD/CAM technology combined with a conventional impression technique to treat a malformed tooth with ceramic veneer in a single appointment. A thin ...veneer (0.4 mm) made of lithium disilicate ceramic was used to correct the shape of the malformed tooth with a minimally invasive preparation using a chairside CAD/CAM system. Thus the treatment can be performed during one appointment. To facilitate the CAD/CAM process and fabrication of the veneer, a scanable model fabricated on a modified gypsum definitive cast was used. The malformed tooth was corrected on the cast by use of a composite resin and an impression was then made. This trimmed impression was used intraorally during the scanning process to facilitate fabrication of the veneer.
Zusammenfassung
Wurzelförmige patientenindividuelle Implantate sind eine Alternative zu konventionellen Implantaten für den direkten Ersatz eines Wurzelrests. Diese Implantate erhalten das ...periimplantäre Weichgewebe nach der Zahnextraktion und haben eine vorhersehbare Ästhetik. Bei einer ausreichenden Compliance des Patienten und einer geeigneten Knochenkonfiguration bieten sie eine weitere Möglichkeit für den Ersatz eines Zahns. Der vorliegende Artikel beschäftigt sich mit der Herstellung und dem kompletten Behandlungsablauf. Anhand von 2 Patientenfällen wird das Vorgehen im Detail beschrieben. Auf die Unterschiede zu konventionellen Implantaten wird eingegangen und die Vor- und Nachteile diskutiert.
Zusammenfassung
Totalprothesen können mittels 3‑D-Druck hergestellt werden. Die möglichen Arbeitsabläufe der Fertigung mittels CAD/CAM („computer-aided design“/„computer-aided manufacturing“) sind ...dabei vielfältig. Die Herstellung ist effizient, kostengünstig und reproduzierbar. Dabei werden die Prothesenbasen gedruckt, für die Zähne können entweder konfektionierte Zahngarnituren verwendet oder individuelle Zahnkränze gedruckt werden. Anhand eines Fallbeispiels werden Entwurf und Fertigung einer Ober- und Unterkiefertotalprothese exemplarisch beschrieben.
Summary
Although knowledge of short‐range kinetic interactions between antagonistic teeth during mastication is of essential importance for ensuring interference‐free fixed dental reconstructions, ...little information is available. In this study, the forces on and displacements of the teeth during kinetic molar biting simulating the power stroke of a chewing cycle were investigated by use of a finite‐element model that included all the essential components of the human masticatory system, including an elastic food bolus. We hypothesised that the model can approximate the loading characteristics of the dentition found in previous experimental studies. The simulation was a transient analysis, that is, it considered the dynamic behaviour of the jaw. In particular, the reaction forces on the teeth and joints arose from contact, rather than nodal forces or constraints. To compute displacements of the teeth, the periodontal ligament (PDL) was modelled by use of an Ogden material model calibrated on the basis of results obtained in previous experiments. During the initial holding phase of the power stroke, bite forces were aligned with the roots of the molars until substantial deformation of the bolus occurred. The forces tilted the molars in the bucco‐lingual and mesio‐distal directions, but as the intrusive force increased the teeth returned to their initial configuration. The Ogden material model used for the PDL enabled accurate prediction of the displacements observed in experimental tests. In conclusion, the comprehensive kinetic finite element model reproduced the kinematic and loading characteristics of previous experimental investigations.
In dentistry the restoration of decayed teeth is challenging and makes great demands on both the dentist and the materials. Hence, fiber-reinforced posts have been introduced. The effects of ...different variables on the ultimate load on teeth restored using fiber-reinforced posts is controversial, maybe because the results are mostly based on non-standardized in vitro tests and, therefore, give inhomogeneous results. This study combines the advantages of in vitro tests and finite element analysis (FEA) to clarify the effects of ferrule height, post length and cementation technique used for restoration. Sixty-four single rooted premolars were decoronated (ferrule height 1 or 2
mm), endodontically treated and restored using fiber posts (length 2 or 7
mm), composite fillings and metal crowns (resin bonded or cemented). After thermocycling and chewing simulation the samples were loaded until fracture, recording first damage events. Using UNIANOVA to analyze recorded fracture loads, ferrule height and cementation technique were found to be significant, i.e. increased ferrule height and resin bonding of the crown resulted in higher fracture loads. Post length had no significant effect. All conventionally cemented crowns with a 1-mm ferrule height failed during artificial ageing, in contrast to resin-bonded crowns (75% survival rate). FEA confirmed these results and provided information about stress and force distribution within the restoration. Based on the findings of in vitro tests and computations we concluded that crowns, especially those with a small ferrule height, should be resin bonded. Finally, centrally positioned fiber-reinforced posts did not contribute to load transfer as long as the bond between the tooth and composite core was intact.
Summary
The selection of local anaesthetic in dental practice is essential to the patient′s comfort and the success of the treatment. Many patients prefer anaesthesia even for short treatments. ...Articaine is a local anaesthetic commonly used for dental practice. The duration of the effect of articaine on the nerve fibres is not yet precisely reported. This study was aimed to evaluate the clinical efficacy of 4% articaine with and without epinephrine in treatment of occlusal caries. Thirty healthy patients were included in this randomised double‐blind study. Each subject received 4% articaine with and without epinephrine (1:100 000). Maxillary infiltration was used for occlusal caries of the maxillary premolars on right and left sides. Quantitative sensory testing (QST) was performed in the innervation area of the infraorbital nerve, and pulp vitality test was performed on restoration‐free canines. Duration of anaesthesia was longer when articaine with epinephrine was used. Articaine without epinephrine showed faster recovery of sensory blockade compared to articaine with epinephrine. The epinephrine‐containing agent, when compared to the plain articaine solution, showed significantly stronger and longer anaesthetic efficacy on the soft tissue by all parameters of QST. Articaine with epinephrine caused a more reliable pulpal analgesia. A pain‐free treatment of the soft tissue up to 15 minutes can be performed under the vasoconstrictor‐free anaesthetic without causing long‐lasting numbness. Epinephrine‐containing articaine delivers a longer, more effective anaesthesia and is preferable for caries treatments and longer invasive treatments of the soft tissue.
Summary Aim of this study was to introduce a feasible and valid technique for the assessment of masticatory performance that is comparable to the standard sieving method. Twenty‐one chewing samples ...(Optosil) comminuted by healthy dentate adults were analysed with a sieving and scanning method. Scanning was performed using a conventional flatbed scanner (1200 dpi). All scanned images underwent image analysis (ImageJ), which yielded descriptive parameters such as area, best‐fitting ellipse for each particle. Of the 2D‐image, a volume was estimated for each particle, which was converted into a weight. To receive a discrete distribution of particle sizes comparable to sieving, five chewing samples were used to calculate a size‐dependent area‐volume‐conversion factor. The sieving procedure was carried out with a stack of 10 sieves, and the retained particles per sieve were weighed. The cumulated weights yielded by either method were curve‐fitted with the Rosin–Rammler distribution to determine the median particle size x50. The Rosin–Rammler distributions for sieving and scanning resemble each other. The distributions show a high correlation (0·919–1·0, n = 21, P < 0·01, Pearson’s correlation coefficient). The median particle sizes vary between 3·83 and 4·77 mm (mean: 4·31) for scanning and 3·53 and 4·55 mm (mean: 4·21) for sieving. On average, scanning overestimates the x50 values by 2·4%. A modified Bland–Altman plot reveals that 95% of the x50 values fall within 10% of the average x50. The scanning method is a valid, simple and feasible method to determine masticatory performance.
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