The relationship between the tensile bond strength (TBS) and three dentin characteristics: remaining dentin thickness (RDT), Ca-concentration, and hardness, were investigated. Sixty-two extracted bovine incisors, divided into four groups, were prepared using 600-grit SiC paper to create flat dentinal surfaces. The materials tested in this study consisted of three commercially available and one experimental dentin bonding systems. The TBS and modes of failure were determined after storage for 24 h in 37 degrees C water. Then RDT, Ca-concentration, and hardness were measured. Data were statistically compared with TBS of each group. The mean bond strength of the commercial materials ranged from 2.5 +/- 0.9 MPa to 7.7 +/- 2.8 MPa. Correlations with Ca-concentration and RDT varied, depending on the product. The bond strength of the experimental material was 9.2 +/- 4.4 MPa and significantly correlated with RDT and hardness. With two of the dentin bonding agents, specimens showed a high number of cohesive fractures in dentin, 40% to 82%. It was concluded that the variability of TBS was influenced by dentinal characteristics in three of the four materials tested.

• MeSH
• adhezivita MeSH
• dentin anatomie a histologie   chemie   MeSH
• dentinová adheziva chemie   MeSH
• pevnost v tahu MeSH
• pryskyřičné cementy * MeSH
• skot MeSH
• složené pryskyřice chemie   MeSH
• testování materiálů MeSH
• tvrdost MeSH
• vápník analýza   MeSH
• vazba zubní * MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Clearfil Bonding Agent MeSH Prohlížeč
• Clearfil Photo Bond MeSH Prohlížeč
• dentinová adheziva MeSH
• pryskyřičné cementy * MeSH
• scotchbond 2 MeSH Prohlížeč
• složené pryskyřice MeSH
• vápník MeSH

Considerable amount of research has been focused on dentin mineralization, odontoblast differentiation, and their application in dental tissue engineering. However, very little is known about the differential role of functionally and spatially distinct types of dental epithelium during odontoblast development. Here we show morphological and functional differences in dentin located in the crown and roots of mouse molar and analogous parts of continuously growing incisors. Using a reporter (DSPP-cerulean/DMP1-cherry) mouse strain and mice with ectopic enamel (Spry2+/- ;Spry4-/- ), we show that the different microstructure of dentin is initiated in the very beginning of dentin matrix production and is maintained throughout the whole duration of dentin growth. This phenomenon is regulated by the different inductive role of the adjacent epithelium. Thus, based on the type of interacting epithelium, we introduce more generalized terms for two distinct types of dentins: cementum versus enamel-facing dentin. In the odontoblasts, which produce enamel-facing dentin, we identified uniquely expressed genes (Dkk1, Wisp1, and Sall1) that were either absent or downregulated in odontoblasts, which form cementum-facing dentin. This suggests the potential role of Wnt signalling on the dentin structure patterning. Finally, we show the distribution of calcium and magnesium composition in the two developmentally different types of dentins by utilizing spatial element composition analysis (LIBS). Therefore, variations in dentin inner structure and element composition are the outcome of different developmental history initiated from the very beginning of tooth development. Taken together, our results elucidate the different effects of dental epithelium, during crown and root formation on adjacent odontoblasts and the possible role of Wnt signalling which together results in formation of dentin of different quality. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

• Klíčová slova
• DENTIN, DENTINOGENESIS, INCISOR, LIBS, MICROSTRUCTURE, MOLAR, ODONTOBLAST, ODONTOGENESIS, PROCESSES, TEETH, WNT SIGNALING,
• MeSH
• buněčná diferenciace MeSH
• dentin * MeSH
• epitel MeSH
• extracelulární matrix - proteiny genetika   MeSH
• myši MeSH
• odontoblasty * MeSH
• odontogeneze MeSH
• řezáky MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• extracelulární matrix - proteiny MeSH

• MeSH
• dentin účinky léků   MeSH
• elektronová mikroskopie MeSH
• lidé MeSH
• odontoblasty fyziologie   MeSH
• zinkfosfátový cement farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• zinkfosfátový cement MeSH

The bonding performance of dental adhesives is most frequently evaluated using the micro-tensile bond strength (μTBS) test. Despite lacking evidence, peripheral specimens are often discarded to avoid regional variability. This study, therefore, examined whether μTBS to central and peripheral dentin differed. Dentin surfaces of extracted human molars were bonded with various self-etch adhesives, built up with a resin composite, cut into beams, and stressed in tension. Failure mode was classified as adhesive, cohesive in dentin, or other using scanning electron microscopy. Since cohesive failures in dentin were frequent and could confound μTBS results, the data from central/peripheral dentin were analyzed using a Weibull competing risk (CR) model distinguishing failure modes, and its outcomes were compared to a conventional failure mode non-distinguishing Weibull model. Based on the strength data of cohesively failed specimens, the CR model also estimated the strength of dentin. For comparison, the ultimate tensile strength (UTS) of dentin was measured in both regions. The conventional model suggested that peripheral μTBS was higher than central μTBS. Conversely, the CR model disclosed no significant difference in μTBS between the regions but indicated a higher strength of peripheral dentin. This finding was confirmed by UTS measurements, and further supported by the significantly higher incidence of cohesive failures in central dentin. Therefore, peripheral specimens can be used in the μTBS test as well as central ones, but a CR model should be used for statistical analysis if cohesive failures in dentin are frequent, as the strength of peripheral dentin is higher.

• Klíčová slova
• Adhesion, Competing risks, Dentin, Failure mode, Weibull analysis,
• MeSH
• dentin MeSH
• dentinová adheziva * MeSH
• lidé MeSH
• pevnost v tahu MeSH
• pryskyřičné cementy MeSH
• složené pryskyřice MeSH
• testování materiálů MeSH
• vazba zubní * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dentinová adheziva * MeSH
• pryskyřičné cementy MeSH
• složené pryskyřice MeSH

Atomic force microscopy (AFM) as one the technique of Scanning Probe Microscopy is useful for imaging of surface structure. This method can yield three-dimensional high-resolution topographic images of sample surfaces by using a scanning technique for conductors and insulators on atomic scale. It is based upon mapping of atomic-forces on a surface of an investigated sample. The method is useful not only in physics and chemistry; it can be also applied in biological fields. Special construction of AFM scanner enables to follow biological samples in liquid environments. Artifacts caused by dehydration of samples are removed this way. Dentin of human teeth is a vital hydrated tissue. It is strongly sensitive to dehydration and drying that are commonly used in preparation of samples in examinations by Scanning Electron Microscopy (SEM). We describe our experience in examination of dentin surfaces of extracted human third molars using contact method of AFM under moist conditions.

• MeSH
• dentin anatomie a histologie   MeSH
• lidé MeSH
• mikroskopie atomárních sil * MeSH
• techniky in vitro MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: Ultra-high-speed (UHS) videography was used to visualize the fracture phenomena at the resin-dentin interface during micro-tensile bond strength (μTBS) test. We also investigated whether UHS videography is applicable for failure-mode analysis. METHODS: Ten human mid-coronal dentin surfaces were bonded using Clearfil SE Bond either in self-etching (SE) or etch-and-rinse (ER) mode. After 24-h water storage, the samples were cut into beams for μTBS test and tested at a cross-head speed of 1 mm/min. The fracture phenomena at the bonded interface were captured using a complementary metal-oxide-semiconductor digital UHS camera at 299,166 frames per second. The failure modes were classified using UHS videography, followed by scanning electron microscopy (SEM) analysis. The failure-mode distributions determined by UHS videography and SEM analysis were statistically analyzed using Fisher's exact test with Bonferroni correction. RESULTS: The crack-propagation speed exceeded 1,500 km/h. No significant difference was found between the SEM and UHS videography failure-mode distributions in the SE mode. A significant difference appeared between them in the ER mode. Significant differences in the incidence of cohesive failures within the adhesive and at the adhesive-composite interface between the SE and ER modes were identified by both SEM and UHS videography. SIGNIFICANCE: UHS videography enabled visualization of the fracture dynamics at the resin- dentin interfaces under tensile load. However, the resolution at such high frame rate was insufficient to classify the failure mode as precisely as that of SEM. Nevertheless, UHS videography can provide more detailed information about the fracture origin and propagation.

• Klíčová slova
• Crack propagation, Dental adhesive systems, Failure mode, Fractographic analysis, Micro-tensile bond-strength test, Ultra-high-speed videography,
• MeSH
• dentin MeSH
• dentinová adheziva * MeSH
• lidé MeSH
• mechanický stres MeSH
• mikroskopie elektronová rastrovací MeSH
• pevnost v tahu MeSH
• povrchové vlastnosti MeSH
• pryskyřičné cementy MeSH
• složené pryskyřice MeSH
• testování materiálů MeSH
• vazba zubní * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dentinová adheziva * MeSH
• pryskyřičné cementy MeSH
• složené pryskyřice MeSH

The dentin-enamel junction (DEJ) is the border where two different mineralized structures - enamel and dentin - meet. The protein-rich DEJ, together with the inner enamel region of mature teeth, is known to exhibit higher fracture toughness and crack growth resistance than bulk phase enamel. However, an explanation for this behavior has been hampered by the lack of compositional information for the DEJ and the adjacent enamel organic matrix (EOM). We studied proteomes of the DEJ and EOM of healthy human molars and compared them with dentin and enamel proteomes from the same teeth. These tissues were cut out of tooth sections by laser capture microdissection, proteins were extracted and cleaved by trypsin, then processed by liquid chromatography coupled to tandem mass spectrometry to analyze the proteome profiles of these tissues. This study identified 46 proteins in DEJ and EOM. The proteins identified have a variety of functions, including calcium ion-binding, formation of extracellular matrix, formation of cytoskeleton, cytoskeletal protein binding, cell adhesion, and transport. Collagens were identified as the most dominant proteins. Tissue-specific proteins, such as ameloblastin and amelogenin, were also detected. Our findings reveal new insight into proteomics of DEJ and EOM, highly mineralized tissues that are obviously difficult to analyze.

• Klíčová slova
• dentin, laser capture microdissection, mass spectrometry, proteome,
• MeSH
• chromatografie kapalinová MeSH
• dentin * MeSH
• lidé MeSH
• mikrodisekce MeSH
• moláry * MeSH
• proteiny metabolismus   MeSH
• proteom analýza   MeSH
• proteomika metody   MeSH
• tandemová hmotnostní spektrometrie MeSH
• zubní sklovina * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteiny MeSH
• proteom MeSH

Proteomic analysis of the human body is a significant recent scientific endeavour. In this study, we investigated the proteomic profile of human dentin using modern analytical and mass spectrometric techniques. Five healthy permanent human molars from five adults were cut, pulverized, denaturated with guanidine buffer, and demineralized with EDTA buffer. The extracted proteins were analysed by gel electrophoresis (SDS-PAGE and two-dimensional gel electrophoresis), digested with trypsin, and separated by liquid chromatography/high-resolution tandem mass spectrometry. We identified 289 proteins with high confidence, 90 of which had not been previously detected in human dentin. Nine (currently hypothetical) proteins were identified for the first time in an actual human sample. The proteins have a variety of functions, including calcium-ion binding, formation of the extracellular matrix, formation of the cytoskeleton, cytoskeletal protein binding, immune response, and transport. In conclusion, this is the first use of two-dimensional electrophoresis for investigating human dentin.

• MeSH
• 2D gelová elektroforéza metody   MeSH
• dentin chemie   MeSH
• elektroforéza v polyakrylamidovém gelu metody   MeSH
• lidé MeSH
• mladý dospělý MeSH
• molár třetí MeSH
• proteiny analýza   chemie   MeSH
• proteomika metody   MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• vysokoúčinná kapalinová chromatografie přístrojové vybavení   metody   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteiny MeSH

OBJECTIVES: To evaluate the effect of smear layer deproteinization using hypochlorous acid (HOCl) with/without metal chlorides (SrCl2 and ZnCl2) on the microtensile bond strength (µTBS) of two simplified adhesives to dentin. METHODS: Human dentin surfaces with a standardized smear layer were pretreated using a 105 ppm HOCl solution with/without SrCl2 (0.05 M, 0.1 M, 0.2 M, 0.4 M) or ZnCl2 (0.05 M, 0.1 M, 0.2 M) for 5 s, 15 s, or 30 s. After the deproteinizing solution was washed out with water for 5 s, 15 s, or 30 s, pretreated surfaces were bonded with one-step self-etch adhesive Bond Force II or universal adhesive Clearfil Universal Bond Quick, and µTBS was measured after 24 h. Additionally, the deproteinizing effects of HOCl solutions with/without the metal chlorides were compared by measuring changes in the amide:phosphate ratio using attenuated total reflection Fourier transform infrared spectroscopy. Statistical analysis was performed using multifactor ANOVA, Tukey's post hoc tests and t-tests (p < 0.05). RESULTS: Pretreatment with pure HOCl for 15 s and 30 s significantly decreased the amide:phosphate ratio (p < 0.05), indicating effective deproteinization, but the µTBS of both adhesives increased significantly only if HOCl was washed out for 30 s (p < 0.05). Increasing the concentrations of metal chlorides enabled shortening of the wash-out time down to 5 s while maintaining the improved µTBS (p < 0.05). The deproteinizing effect of HOCl was not significantly altered by the addition of metal chlorides (p > 0.05). SIGNIFICANCE: The effectiveness of smear layer deproteinization using HOCl can be improved by the addition of metal chlorides, as their increasing concentration allowed to shorten the wash-out time from 30 s down to 5 s.

• Klíčová slova
• Adhesion, FTIR, Hypochlorous acid, Microtensile bond strength, Pretreatment, Smear layer deproteinization, Strontium chloride, Zinc chloride,
• MeSH
• amidy analýza   farmakologie   MeSH
• chloridy analýza   farmakologie   MeSH
• dentin chemie   MeSH
• dentinová adheziva chemie   MeSH
• fosfáty farmakologie   MeSH
• kyselina chlorná analýza   farmakologie   MeSH
• lidé MeSH
• pevnost v tahu MeSH
• pryskyřičné cementy chemie   MeSH
• smear layer * MeSH
• testování materiálů MeSH
• vazba zubní * MeSH
• zubní cementy farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amidy MeSH
• chloridy MeSH
• dentinová adheziva MeSH
• fosfáty MeSH
• kyselina chlorná MeSH
• pryskyřičné cementy MeSH
• zubní cementy MeSH

The presented study verifies the desensibilization effect and the plaque score influence of a therapeutical toothpaste Fluocaril bi-fluoré 250 applied in a chosen group of patients with sensitive exposed tooth necks. In the course of six-week application of the toothpaste Fluocaril bi-fluoré 250, a decrease of the sensitivity of the exposed dentin, tested by cold and tactile stimuli and an improvement of the oral hygiene estimated with the help of plaque score were observed in the studied group. After withdrawal of the treatment, the estimated criteria returned to the initial values recorded at the beginning of the experiment.

• MeSH
• citlivost dentinu terapie   MeSH
• dospělí MeSH
• fixní kombinace léků MeSH
• fluorid sodný aplikace a dávkování   MeSH
• fosfáty aplikace a dávkování   MeSH
• indexy plaku * MeSH
• lidé MeSH
• mladiství MeSH
• zubní pasty * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fixní kombinace léků MeSH
• fluocaril MeSH Prohlížeč
• fluorid sodný MeSH
• fosfáty MeSH
• zubní pasty * MeSH