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Aim: The aim of this study was to compare the adhesion of glass-ceramic overlays to tooth structure, under the effect of shear forces, using different bonding systems. Materials and Methods: Thirty healthy lower third molars were selected and randomly allocated into three groups (n = 10). Group 1: overlays bonded to tooth structure using Panavia V5 with immediate dentin sealing (IDS); Group 2: overlays bonded using Panavia V5 without IDS; and Group 3: overlays bonded using heated composite combined with a bonding agent with IDS. All the restorations were made of glass-ceramic (Suprinity, Vita). The restored teeth were then stored in distilled water for 7 days and at room temperature. Shear forces were applied using a universal testing machine. Load and displacement were recorded at intervals of 0.1 s. A statistical analysis was used to compare the groups. Results: The mean resistance to fractures ± standard deviation obtained for the Groups 1, 2, and 3 was, respectively, 15.7440 ± 2.13, 12.0750 ± 1.41, and 8.33364 ± 2.85 MPa. The analysis of variance was highly significant (P < 0.001) allowing us to reject the null hypothesis of equality between the three groups. Comparisons between pairs also provided significant results. Conclusion: Bonding using Panavia V5 with IDS showed a better resistance to shear forces when compared to other bonding techniques. The application of IDS increased the adhesion.

Objectives: The use of zirconia as a framework for prosthetic restorations is increasing due to its favorable mechanical properties. Zirconia also has remarkable aesthetic properties when used as a framework and covered with a layer of cosmetic ceramic. The aim of this study was to compare the fracture toughness of three types of aesthetic ceramics, namely VITA VM®9, ceraMotion® Zr, and IPS e.max® Ceram. Materials and Methods: Three groups of aesthetic ceramics (n=10) were subjected to three-point bending tests. The force leading to fracture was recorded for each sample to measure the impact of the ceramic type on the solidity of the framework. The type of fracture has not been studied in this work. One-way analysis of variance (ANOVA) was used to statistically analyze the results. Results: The statistical analysis showed significantly different fracture toughness values among the three groups. IPS e.max® showed the lowest fracture toughness (25.42 MPa) compared to VITA VM®9 and ceraMotion® Zr (respectively 40.39 MPa; P

Objective: Adhesives systems have a drawback when utilized for bonding orthodontic brackets: they shrink during photopolymerization creating microleakage. The aim of this study was to assess the stability of different orthodontic adhesives around brackets and enamel. Materials and Methods: Sixty noncarious mandibular premolars extracted for orthodontic reasons were randomly divided into six groups of adhesives used for bonding brackets to dental enamel: NeoBond® Light Cure Adhesive Kit, Transbond™ Plus Self-Etching, Victory V-Slot APC PLUS® + Transbond™ MIP, Rely-A-Bond® Kit, Light Cure Orthodontic Adhesive Kit (OptiBond®), and Transbond™ MIP. Following bonding, all teeth underwent 2500 cycles of thermal cycling in baths ranging from 5°C to 55°C before being immersed in 2% methylene blue for 24 h. All samples were examined under a binocular microscope to assess the degree of microleakage at the “bracket-adhesive” and “adhesive-enamel” interfaces in the gingival and occlusal regions of the bracket. Results: A significant difference was found at the “occlusal bracket-adhesive” interface. The highest microleakage values were found in the occlusal region, although no significant. Microleakage was observed in all groups. Conclusion: Group 2 had the highest microleakage values whereas Group 6 had the lowest values.

Purpose The micropercolation testing of dental materials is currently used to evaluate the sealing ability. The aim of the present study is to compare the sealing ability of distinct assembling materials for zirconium oxide peripheric crowns. Materials and Methods One hundred teeth were prepared to be thermocycled after being distributed at random in 10 groups each containing 10 specimens (group 1: Fuji One; group 2: Fuji Plus; group 3: Variolink II; group 4: RelyX Ultimate; group 5: Multilink; group 6: Panavia F2.0; group 7: Bifix QM; group 8: RelyX Unicem 2; group 9: Maxcem Elite; group 10: Bifix SE). Results RelyX Unicem 2 and RelyX Ultimate yielded high imperviousness percentages. The sealing ability in the vestibular area and lingual area is indeed best in the presence of these two materials. Our results show no difference whether the chamfer is situated in the enamel or in the dentin. Conclusion A zirconium crown should be preferably cemented with a glass-ionomer cement modified by addition of resin material.

Aim. This study sought to compare the microleakage of three adhesive systems in the context of Erbium-YAG laser and diamond bur cavity procedures. Cavities were restored with composite resin. Materials and Methods. Standardized Class V cavities were performed in 72 extracted human teeth by means of diamond burs or Er-YAG laser. The samples were randomly divided into six groups of 12, testing three adhesive systems (Clearfil s3 Bond Plus, Xeno® Select, and Futurabond U) for each method used. Cavities were restored with composite resin before thermocycling (methylene blue 2%, 24 h). The slices were prepared using a microtome. Optical microscope photography was employed to measure the penetration. Results. No statistically significant differences in microleakage were found in the use of bur or laser, nor between adhesive systems. Only statistically significant values were observed comparing enamel with cervical walls (p < 0.001). Conclusion. It can be concluded that the Er:YAG laser is as efficient as diamond bur concerning microleakage values in adhesive restoration procedures, thus constituting an alternative tool for tooth preparation., SCOPUS: ar.j, info:eu-repo/semantics/published

Purpose To compare different dental bonding systems that are currently available on the market. Materials and methods A total of 100 extracted, intact third molars were coated in resin, cut, and divided into 10 groups of 10 molars each. Molars were bonded to zirconia blocks with a different bonding system per group. Resistance to shear forces was tested using a universal traction machine. Samples were observed under scanning electron microscopy (SEM) to determine the type of fracture. Results Statistical analyses showed a significant influence of adhesive on the zirconia-dentin assembly's resistance to shear forces. SEM analysis showed mainly adhesive and mixed fractures. Conclusion Dentin bonding systems without adhesive capability showed better results than self-etch systems.

Purpose The aim of this study was to investigate the effect of coloring on the interfacial surface adhesion between a zirconia framework and ceramic veneer using three-point flexural bonding strength. Materials and methods A total of 40 zirconia bars (Zirlux ST1; DE Healthcare) were cut and divided into two groups of 20 (Groups 1 and 2). The two groups were then further split and divided into four groups of 10 each (Groups 1a, 1b, 2a, and 2b). Groups 1a and 1b tested adhesion of uncolored zirconia and two different shades of ceramic veneer, and Groups 2a and 2b tested adhesion of zirconia colored with two different coloring liquids and one shade of ceramic veneer. Results Some coloring liquids used to color zirconia can significantly affect the bond strength between zirconia and the veneer, whereas ceramic veneer shades do not influence adhesion. Conclusion Bonding strength between zirconia framework and ceramic veneer is affected by the coloring of the zirconia.

PURPOSE. Conventional resin-bonded fixed partial dentures (RBFPDs) are usually made with a two-retainer design. Unlike conventional RBFPDs, cantilever resin-bonded fixed partial dentures (Cantilever RBFPDs) are, for their part, made with a single-retainer design. The aim of this study was to compare the effect of tooth surface preparation on the bond strength of zirconia cantilever single-retainer RBFPDs. The objective is to evaluate the shear bond strength of these single-retainer RBFPDs bonded on 3 different amount of tooth surface preparation. MATERIALS AND METHODS. Thirty extracted bovine incisors were categorized to 3 groups (n=10), with different amounts of tooth surface preparations. Teeth were restored with single-retainer RBFPDs with different retainer surfaces: large retainer of 32 mm2; medium retainer of 22 mm2; no retainer and only a proximal connecting box of 12 mm2. All RBFPDs were made of zirconia and were bonded using an adhesive system without adhesive capacity. Shear forces were applied to these restorations until debonding. RESULTS. Mean shear bond strength values for the groups I, II, and II were 2.39±0.53 MPa, 3.13±0.69 MPa, and 5.40±0.96 MPa, respectively. Statistical analyses were performed using a one-way ANOVA test with Bonferroni post-hoc test, at a significance level of 0.001. Failure modes were observed and showed a 100% adhesive fracture. CONCLUSION. It can be concluded that the preparation of large tooth surface preparation might be irrelevant. For zirconia single-retainer RBFPD, only the preparation of a proximal connecting box seems to be a reliable and minimally invasive approach. The differences are statistically significant., SCOPUS: ar.j, info:eu-repo/semantics/published

Introduction: Our study's objective was to compare resistance to fracture between endocrown and conventional post and core restorations when subjected to shear force. Materials and Methods: Thirty human mandibular premolars were extracted for orthodontic reasons, endodontically treated, and restored using three different methods: endocrown, glass fiber post and composite resin core, and metal post. All the crowns were made from IPS e.max ceramic. Shear forces were applied to these restorations using a test machine until breakage. Load and displacement were recorded every 0.1 s. Results: No significant difference was observed in resistance to fracture between glass fiber post and metal post. No relationship between the displacement of prosthetic dental system and type of material used was uncovered and by comparing the type of fracture with the restoration material used. However, a greater number of favorable fractures were observed in the glass fiber group whereas most of the fractures in the endocrown and metal post groups were unfavorable. Conclusion: Endocrown displays better resistance to fracture compared to conventional post and core restorations. In addition, endocrown did not show more displacement or cause more unfavorable fractures than the conventional restorations. This restoration may represent a reliable alternative for restoring a damaged, endodontically treated tooth., SCOPUS: ar.j, info:eu-repo/semantics/published

Aim: The aim of this study was to compare the adhesion of glass-ceramic overlays to tooth structure, under the effect of shear forces, using different bonding systems. Materials and Methods: Thirty healthy lower third molars were selected and randomly allocated into three groups (n = 10). Group 1: overlays bonded to tooth structure using Panavia V5 with immediate dentin sealing (IDS); Group 2: overlays bonded using Panavia V5 without IDS; and Group 3: overlays bonded using heated composite combined with a bonding agent with IDS. All the restorations were made of glass-ceramic (Suprinity, Vita). The restored teeth were then stored in distilled water for 7 days and at room temperature. Shear forces were applied using a universal testing machine. Load and displacement were recorded at intervals of 0.1 s. A statistical analysis was used to compare the groups. Results: The mean resistance to fractures ± standard deviation obtained for the Groups 1, 2, and 3 was, respectively, 15.7440 ± 2.13, 12.0750 ± 1.41, and 8.33364 ± 2.85 MPa. The analysis of variance was highly significant (P < 0.001) allowing us to reject the null hypothesis of equality between the three groups. Comparisons between pairs also provided significant results. Conclusion: Bonding using Panavia V5 with IDS showed a better resistance to shear forces when compared to other bonding techniques. The application of IDS increased the adhesion.

Introduction: Our study's objective was to compare resistance to fracture between endocrown and conventional post and core restorations when subjected to shear force. Materials and Methods: Thirty human mandibular premolars were extracted for orthodontic reasons, endodontically treated, and restored using three different methods: endocrown, glass fiber post and composite resin core, and metal post. All the crowns were made from IPS e.max ceramic. Shear forces were applied to these restorations using a test machine until breakage. Load and displacement were recorded every 0.1 s. Results: No significant difference was observed in resistance to fracture between glass fiber post and metal post. No relationship between the displacement of prosthetic dental system and type of material used was uncovered and by comparing the type of fracture with the restoration material used. However, a greater number of favorable fractures were observed in the glass fiber group whereas most of the fractures in the endocrown and metal post groups were unfavorable. Conclusion: Endocrown displays better resistance to fracture compared to conventional post and core restorations. In addition, endocrown did not show more displacement or cause more unfavorable fractures than the conventional restorations. This restoration may represent a reliable alternative for restoring a damaged, endodontically treated tooth.

The present study aimed to investigate the effects of cytochalasin B (20 μM) on the uptake of 3-O-[(14)C]-methyl-D-glucose or D-[U-(14)C]glucose (8.3 mM each) by BRIN-BD11 cells. Taking into account the distribution space of tritiated water ((3)HOH), which was unexpectedly increased shortly after exposure of the cells to cytochalasin B and then progressively returned to its control values, and that of L-[1-(14)C]glucose, used as an extracellular marker, it was demonstrated that cytochalasin B caused a modest, but significant inhibition of the uptake of D-glucose and its non-metabolized analog by the BRIN-BD11 cells. These findings resemble those observed in acinar or ductal cells of the rat submaxillary gland and displayed a relative magnitude comparable to that found for the inhibition of D-glucose metabolism by cytochalasin B in purified pancreatic islet B cells. These findings reinforce the view that the primary site of action of cytochalasin B is located at the level of the plasma membrane.

Background/Aim: The submandibular gland is one of the three major salivary glands, producing a mixed secretion; this saliva is hypotonic compared to plasma. It also secretes glucose, but the mechanisms responsible for this process are poorly understood. Our study addressed the question whether glucose transporters are expressed and how are they localized within specific rodent submandibular cells, in order to estimate a possible implication in salivary glucose disposal. Methods: Immunohistochemistry, RT-qPCR and Western blotting were performed to determine the presence/localization of glucose transporters in rodent submandibular glands. Results: GLUT4 was identified in the submandibular salivary gland at both mRNA and protein level. The immunohistochemical analysis revealed its localization preponderantly in the ductal cells of the gland, near to the basolateral. SGLT1 and GLUT1 were highly expressed in submandibular tissues in both acinar and ductal cells, but not GLUT2. These results were confirmed by RT-qPCR. It was also documented that insulin stimulates the net uptake of D-glucose by ductal rings prepared from submandibulary salivary glands, the relative magnitude of such an enhancing action being comparable to that found in hemidiaphragms. Conclusion: At least three major glucose transporters are expressed in the rodent submandibular glands, of which GLUT4 is specifically localized near the basolateral side of ductal structures. This points-out its possible role in regulating glucose uptake from the bloodstream, most likely to sustain ductal cellular metabolism. © 2014 S. Karger AG, Basel., SCOPUS: ar.j, info:eu-repo/semantics/published

The aim of the present study is to propose a tentative model for d-glucose turnover in human saliva. The whole saliva and the saliva from parotid and submandibular/sublingual glands were collected by use of the Salivette™.The saliva glucose concentration was measured by the hexokinase method, saliva bacteria glycolysis by use of d-[5-(3)H] glucose, and the saliva ATP content by the luciferase method. The concentration of glucose amounted to 43.9±6.3 (n=29), 197.5±17.3 (n=29), 104.0±12.4 (n=27) μM in whole saliva, parotid saliva and submandibular/sublingual saliva, respectively. The rate of d-glucose utilization by oral bacteria at a physiological concentration of d-glucose in saliva (50μM) was estimated at 0.047±0.003 (n=11) nmol/min per 10(6) bacteria. Unstimulated salivary d-glucose turnover rate, as calculated from the amount of glucose secreted in saliva which comes from parotid and submandibular and sublingual glands represented 214.6±19.1%/min. In order for salivary d-glucose production to match bacterial utilization of the hexose, the total number of oral bacteria was estimated at about 2.0×10(9) bacteria, in fair agreement with previously published data.This study thus provides support for a tentative model for d-glucose turnover in human saliva.

Background/Aims: The expression and localization of several distinct glucose transporters (GLUT1, GLUT2, GLUT4, and SGLT1) was recently characterized in the parotid gland of normal rats by quantitative real-time PCR analysis, immunohistochemistry and Western blotting. The major aims of the present study was to compare the mRNA expression of these glucose transporters in both the parotid gland and submaxillary gland of control rats, streptozotocin-induced diabetic rats and hereditarily diabetic Goto-Kakizaki rats. Methods: Quantitative real-time PCR analysis was performed in the parotid and submaxillary salivary glands and, for purpose of comparison, also in the heart, kidney, liver, lung, muscle and pancreas from control animals and either streptozotocin-treated or Goto-Kakizaki rats. Results: The expression of GLUT4, but not GLUT1 or SGLT1, mRNA was decreased in the diabetic rats. The results also allow comparing both the mRNA expression level of the four glucose transporters in salivary glands and six other organs, and the diabetes-induced changes in such an expression in distinct locations. Conclusion: The mRNA expression of the insulin-dependent GLUT4 transporter was the sole to be significantly decreased in the salivary glands of diabetic animals. The possible consequence of such a decrease in terms of the control of salivary glucose concentration requires further investigation. Copyright © 2012 S. Karger AG, Basel., SCOPUS: ar.j, info:eu-repo/semantics/published

Background/Aims: Salivary glucose is often considered as being from glandular origin. Little information is available, however, on the possible role of glucose transporters in the secretion of the hexose by salivary glands. The major aim of the present study was to investigate the expression and localization of several distinct glucose transporters in acinar cells of rat parotid glands. Methods: Quantitative real-time PCR analysis, immunohistochemistry and western blotting techniques were used to assess the presence of SGLT1, GLUT1, GLUT2 and GLUT4 in acinar cells of rat parotid glands. Results: Quantitative real-time PCR documented the expression of SGLT1 and GLUT1 in parotid tissues, with a much lower level of GLUT4 mRNA and no expression of GLUT2 mRNA. Western blot analysis revealed the presence of SGLT1, GLUT1 and GLUT4 proteins, but not GLUT2 proteins in the parotid extract. Immunohistochemistry confirmed these findings. SGLT1 was specifically located at the baso-lateral membrane, co-localizing with Na + /K + ATPase. GLUT1 was found both at the baso-lateral and apical level. GLUT4 appeared to be also located at the baso-lateral level. However, too little GLUT4 was present to allow co-localization labeling. Conclusion: Based on these findings, a model is proposed for the transport of glucose into the acinar cells and thereafter into the acinar lumen.

The micropercolation testing of dental materials is currently used to evaluate the sealing ability. The aim of the present study is to compare the sealing ability of distinct assembling materials for zirconium oxide peripheric crowns.One hundred teeth were prepared to be thermocycled after being distributed at random in 10 groups each containing 10 specimens (group 1: Fuji One; group 2: Fuji Plus; group 3: Variolink II; group 4: RelyX Ultimate; group 5: Multilink; group 6: Panavia F2.0; group 7: Bifix QM; group 8: RelyX Unicem 2; group 9: Maxcem Elite; group 10: Bifix SE).RelyX Unicem 2 and RelyX Ultimate yielded high imperviousness percentages. The sealing ability in the vestibular area and lingual area is indeed best in the presence of these two materials. Our results show no difference whether the chamfer is situated in the enamel or in the dentin.A zirconium crown should be preferably cemented with a glass-ionomer cement modified by addition of resin material.

The present study deals with the possible effects of selected environmental agents upon the uptake and metabolism of d-glucose in isolated acinar and ductal cells from the rat submandibular salivary gland. In acinar cells, the uptake of d-[U-(14) C]glucose and its non-metabolised analogue 3-O-[(14) C-methyl]-d-glucose was not affected significantly by phloridzin (0.1 mM) or substitution of extracellular NaCl (115 mM) by an equimolar amount of CsCl, whilst cytochalasin B (20 μM) decreased significantly such an uptake. In ductal cells, both phloridzin and cytochalasin B decreased the uptake of d-glucose and 3-O-methyl-d-glucose. Although the intracellular space was comparable in acinar and ductal cells, the catabolism of d-glucose (2.8 or 8.3 mM) was two to four times higher in ductal cells than in acinar cells. Phloridzin (0.1 mM), ouabain (1.0 mM) and cytochalasin B (20 μM) all impaired d-glucose catabolism in ductal cells. Such was also the case in ductal cells incubated in the absence of extracellular Ca(2+) or in media in which NaCl was substituted by CsCl. It is proposed that the ductal cells in the rat submandibular gland are equipped with several systems mediating the insulin-sensitive, cytochalasin B-sensitive and phloridzin-sensitive transport of d-glucose across the plasma membrane.

The present study deals with the possible effects of selected environmental agents upon the uptake and metabolism of d-glucose in isolated acinar and ductal cells from the rat submandibular salivary gland. In acinar cells, the uptake of d-[U-(14) C]glucose and its non-metabolised analogue 3-O-[(14) C-methyl]-d-glucose was not affected significantly by phloridzin (0.1 mM) or substitution of extracellular NaCl (115 mM) by an equimolar amount of CsCl, whilst cytochalasin B (20 μM) decreased significantly such an uptake. In ductal cells, both phloridzin and cytochalasin B decreased the uptake of d-glucose and 3-O-methyl-d-glucose. Although the intracellular space was comparable in acinar and ductal cells, the catabolism of d-glucose (2.8 or 8.3 mM) was two to four times higher in ductal cells than in acinar cells. Phloridzin (0.1 mM), ouabain (1.0 mM) and cytochalasin B (20 μM) all impaired d-glucose catabolism in ductal cells. Such was also the case in ductal cells incubated in the absence of extracellular Ca(2+) or in media in which NaCl was substituted by CsCl. It is proposed that the ductal cells in the rat submandibular gland are equipped with several systems mediating the insulin-sensitive, cytochalasin B-sensitive and phloridzin-sensitive transport of d-glucose across the plasma membrane.

The present study aimed to investigate the effects of cytochalasin B (20 μM) on the uptake of 3-O-[14C]-methyl-D-glucose or D-[U-14C]glucose (8.3 mM each) by BRIN-BD11 cells. Taking into account the distribution space of tritiated water (3HOH), which was unexpectedly increased shortly after exposure of the cells to cytochalasin B and then progressively returned to its control values, and that of L-[1-14C]glucose, used as an extracellular marker, it was demonstrated that cytochalasin B caused a modest, but significant inhibition of the uptake of D-glucose and its non-metabolized analog by the BRIN-BD11 cells. These findings resemble those observed in acinar or ductal cells of the rat submaxillary gland and displayed a relative magnitude comparable to that found for the inhibition of D-glucose metabolism by cytochalasin B in purified pancreatic islet B cells. These findings reinforce the view that the primary site of action of cytochalasin B is located at the level of the plasma membrane.

Introduction Une augmentation de la concentration du glucose dans la salive a ete clairement demontree chez les sujets diabetiques et les modeles animaux de diabete. Pourtant, l’origine et les mecanismes de transport du glucose salivaire restent meconnus. Objectif identifier les transporteurs de glucose dans les glandes sous-maxillaires et etudier leur expression et localisation dans un modele de rat diabetique. Materiels et methodes Les transporteurs de glucose de la famille Glut et SGLT ont ete etudies par immunohistochimie, Western Blot et RT-qPCR dans les glandes sous-maxillaires de trois especes differentes et dans des rats Wistar rendus diabetiques par injection ip. de streptozotocine (STZ, 65 mg/kg). Resultats Glut1, Glut2 et Glut4 ainsi que le co-transporteur Na+/glucose SGLT1 ont ete identifies dans les sous-maxillaires chez l’humain, le rat et la souris. Glut2 a ete detecte dans les canaux inter-lobulaires et stries, avec une plus forte immunoreactivite chez l’humain. L’ARNm de Glut4 et de deux de ses facteurs de transcription, PGC1α et FOXO1 ont ete aussi detectes dans les sous-maxillaires de rat. Glut4 est exprime dans les membranes baso-laterales et dans le cytosol des cellules ductales et acinaires muqueuses, avec une predominance ductale chez l’humain. Afin d’etablir un possible role de ces transporteurs du glucose dans l’augmentation de glucose salivaire observee en diabete, nous avons quantifie leur transcription dans les glandes des rats STZ (glycemie a jeun 86,33 ± 11,15 mg/dL) versus des rats controles (glycemie a jeun 363 ± 138,4 mg/dL). Les resultats preliminaires montrent que parmi les transporteurs etudies, l’ARNm de Glut4 est significativement augmente (p Conclusion Quatre transporteurs de glucose participent au transport du glucose dans les glandes sous-maxillaires dont l’expression de Glut4 est alteree dans les glandes des animaux diabetiques.