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1.
Braz Oral Res ; 34: e001, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32022221

RESUMO

This study analyzed the effect of prior application of copaiba oil (CO) emulsions as a dentin cleaning substance on microleakage and microtensile adhesive strength. Twenty-five premolars and sixty-four molars were used for microleakage and microtensile assays. For the microleakage assays, specimens with standard class V cavities were divided (n = 5), according to the tested CO emulsions: CO10%X, CO10%Y, and CO10%Z, as well as chlorhexidine 2% (CHX) and distilled water (DW), as positive and negative controls, respectively. Restorations were performed using the Adper Single Bond® and/or Clearfil SE Bond® systems. Cervical, occlusal, distal and mesial sections were assessed for tracer penetration degree at the composite/tooth interface. For the microtensile assay, healthy molars were divided into sixteen groups, in which artificial caries were induced in half of the groups. Dentin surfaces were treated with CO10%X and CO10%Y, CHX and DW. Microtensile bond strength was measured by fixing each sample to the plate of a universal testing machine operated at a speed of 0.5 mm/minute until failure. Dentin treated with CO10%X showed a lower infiltration rate than dentin treated with the other CO emulsions, CHX2% and DW. According to the microtensile assay, both healthy and affected dentin treated with CO10%X and Adper Single Bond® adhesive system presented higher adhesive strength. CO emulsion, used as a dentin biomodifier, interfered positively in microleakage and improved adhesive strength after acid etching in the Adper Single Bond® adhesive system, or before applying the Clearfil SE Bond® self-etching system.


Assuntos
Colagem Dentária/métodos , Adesivos Dentinários/química , Dentina/efeitos dos fármacos , Fabaceae/química , Óleos Vegetais/química , Análise de Variância , Clorexidina/química , Resinas Compostas/química , Cimentos Dentários/química , Infiltração Dentária , Dentina/química , Emulsões/química , Humanos , Teste de Materiais , Reprodutibilidade dos Testes , Cimentos de Resina/química , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração
2.
Niger J Clin Pract ; 22(10): 1441-1447, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31607737

RESUMO

Background: There was no enough data about the appropriate surface cleaning of core composite material after temporary cementation. Aim: To evaluate the effects of surface cleaning techniques on initial shear bond strength (SBS) between core composite material and resin nanoceramic crown materials after temporary cementation. Material and Methods: Cubic specimens were prepared from prosthetic materials, including Lava Ultimate. Cylinder-shaped composites were cemented to glass slides with eugenol-free temporary cement, resulting in a total of 44 cylinders (n = 11). The surfaces of composite cylinders were then cleaned with an Er, Cr:YSGG laser, 37% orthophosphoric acid, yellow tape diamond bur, or dental explorer. Cleaned cylinders were bonded to cubic specimens with resin cement. Initial SBS tests were performed with a universal testing machine at 0.5 mm/min crosshead speed. One-way ANOVA and post hoc Tukey tests were used to analyze the obtained data (P =0.05). Results: Initial SBS values were significantly affected by the different surface cleaning methods (P <.05). The highest SBS value was obtained with the laser group (SBS = 17.14), while the lowest was obtained with dental explorer group (SBS = 5.95). There was no significant difference between the diamond bur group and the laser group (P =0.982). Conclusions: Laser irradiation or yellow tape diamond bur cleaning of the core composite surface could be recommended to strengthen bond strength between the resin luting cement and the core composite. Before adhesive or conventional cementation of prosthetic restoration, the core composite surface should be cleaned.


Assuntos
Colagem Dentária/métodos , Cimentos Dentários/química , Corrosão Dentária/métodos , Adesivos Dentinários/química , Vidro/química , Lasers de Estado Sólido/uso terapêutico , Cimentos de Resina/química , Cimentação , Resinas Compostas/química , Cimentos de Ionômeros de Vidro , Humanos , Teste de Materiais , Resistência ao Cisalhamento , Propriedades de Superfície
3.
Gen Dent ; 67(5): e1-e6, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31454330

RESUMO

This study evaluated the influence of operator skill on the shear bond strength of a self-adhesive resin cement to dentin after different adhesive treatments. Flat dentin surfaces were prepared on 160 extracted molars. The teeth were distributed evenly (n = 80) to 2 groups based on the operator's skill (undergraduate dental student vs operative dentistry specialist). The teeth in each operator group were distributed into 5 groups based on pretreatments used before they were cemented to indirect composite resin cylinders with Panavia SA Luting Plus resin cement. The operators prepared the dentin surfaces for bonding according to the following pretreatment groups: 1, no treatment; 2, phosphoric acid etching; 3, Clearfil Universal Bond in etch-and-rinse mode; 4, Clearfil Universal Bond in self-etching mode; and 5, Clearfil SE Bond 2-step adhesive. After cementation was performed by the 2 operator groups, shear bond strength testing was performed, and data were analyzed with 2-way analysis of variance. The effects of operator skill and surface pretreatment and their cumulative effect were statistically significant (P < 0.05). The shear bond strength of the control group in the student group was significantly greater than that of the specialist group (P = 0.02). In group 5 (2-step adhesive), the shear bond strength of the specialist group was significantly greater than that of the student group (P < 0.001). The use of acid etching and the 3 adhesive treatments improved the bonding ability of resin cement for the expert group. This positive effect was observed only in the etch-and-rinse and self-etching modes for the student group. Extensive clinical experience did not have a positive effect on the bonding effectiveness of resin cement with no pretreatment, while the expert group showed better results in applying this cement with a 2-step adhesive pretreatment.


Assuntos
Colagem Dentária , Cimentos Dentários/química , Adesivos Dentinários/química , Cimentos de Resina , Análise do Estresse Dentário , Humanos , Teste de Materiais , Estresse Mecânico , Propriedades de Superfície
4.
Braz Oral Res ; 33: e027, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31269112

RESUMO

Nowadays, demand for esthetic restorations has risen considerably; thus, nonmetal esthetic posts made of either high-strength ceramics or reinforced resins, such as fiber-reinforced resin posts, have become more and more popular. Important characteristics of fiber-reinforced posts involve a modulus of elasticity similar to dentin and their ability to be cemented by an adhesive technique. A total of 36 maxillary incisors were divided into four groups. In this study, four adhesively luted fiber-reinforced (glass fiber, quartz glass fiber, zirconia glass fiber and woven polyethylene fiber ribbon) post systems were used. Post spaces were prepared by employing drills according to the protocol established for each group, and each post was adhesively luted with one of three adhesive systems. Three segments per root apical to the cementoenamel junction (CEJ) were obtained by sectioning the root under distilled water with a carbon spare saw. The samples (total of 108 sections) were 2.0±0.1 mm in thickness and they were stored individually in black film canisters with sterile distilled water. In order to determine the bond strength, the bonding area of each specimen was measured, and specimens were attached to a device to test microtensile strength at a speed of 1 mm/min. The analyses revealed no statistically significant differences between the adhesive systems and fiber-reinforced posts. (P> 0.05). However, the coronal portion of the root dentin had the highest bond strength. Adhesive systems used along with fiber-reinforced resin posts demonstrated reliable bonding.


Assuntos
Resinas Compostas , Coroas , Colagem Dentária/métodos , Adesivos Dentinários , Cimentos de Resina , Resinas Compostas/química , Esmalte Dentário , Cavidade Pulpar , Análise do Estresse Dentário , Dentina , Adesivos Dentinários/química , Vidro , Humanos , Quartzo/química , Cimentos de Resina/química , Resistência à Tração , Zircônio
5.
Photobiomodul Photomed Laser Surg ; 37(7): 428-433, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31265378

RESUMO

Objective: Evaluate the bond strength of repairs made on composite resin following the treatment of the surface of the flaw with different bonding agents and/or CO2 laser. Background: The influence of CO2 laser and its interaction with other bonding agents on the surface of the flaw is not yet known. In this study, CO2 laser was chosen to treat the surface of the flaw due to its capacity to promote irregularities on the surface that enhance mechanical micro-retention. Methods: A block was created with Vitra APS nanohybrid composite resin (color: A3; FGM, Joinville, Brazil) measuring 5 mm in width, length, and depth (volume: 125 mm3). The surface of the flaw was treated before the repair with an adhesive, silane bonding agent, and/or CO2 laser. Six specimens were created in composite resin for each group (total: n = 36): G1: resin+resin; G2: adhesive+resin; G3: laser+adhesive; G4: laser+silane+adhesive; G5: silane+adhesive; G6: laser+silane. After the repair, the surfaces of the fracture of all specimens, which were submitted to the microtraction test, were analyzed under an optical microscope. Bond strength values obtained according to the type of surface treatment were tabulated and submitted to the Kruskal-Wallis test. Dunn's test was used to compare means. Results: G3 and G4 had significantly higher bond strength values compared to all other groups tested. Adhesive fractures predominated in all groups. However, G3 and G4 had a higher percentage of cohesive fractures compared to the other groups. Conclusions: The application of CO2 laser as a surface treatment led to greater bond strength of composite resin repairs in comparison with the groups that only received treatment with a burr and silanization. The groups submitted to CO2 laser also had a significantly lower number of adhesive failures when submitted to the microtraction test.


Assuntos
Resinas Compostas/química , Colagem Dentária , Esmalte Dentário/efeitos da radiação , Corrosão Dentária/métodos , Materiais Dentários/química , Lasers de Gás , Dióxido de Carbono , Análise do Estresse Dentário , Adesivos Dentinários/química , Teste de Materiais , Resistência ao Cisalhamento/efeitos da radiação , Estresse Mecânico , Propriedades de Superfície
6.
Microsc Res Tech ; 82(7): 1032-1040, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30866096

RESUMO

The aim of this in-vitro study was to evaluate microtensile bond strength (µTBS) of two different self-adhesive composites (SACs) on the permanent dentin by applying five different universal adhesive systems. In this study, two different SACs [Vertise Flow (VF), Fusio Liquid Dentin (FLD)] and five different bonding systems [Clearfil Universal Bond Quick (CUB), Single Bond Universal (SBU), All Bond Universal (ABU), Prime Bond Universal (PBU), Futurabond U (FBU)] were used. A total of 22 groups were created in which SACs were applied without adhesive and with five different universal bonding agents in total-etch (TE) and self-etch (SE) modes. Two hundred and forty test sticks were obtained using 48 healthy human molar teeth in total with groups having 10 samples each. The µTBS test was applied to each sample in the Universal test device and the data obtained were analyzed statistically by variance analysis and Tukey HSD test. In addition, the resin-dentin interface and fractures modes in the groups were examined by SEM. Upon examining the µTBS results, the highest values were seen in the use of SBU adhesive in TE mode in VF group, while the lowest values were seen in the FLD control group. The difference between the control and experimental groups was found statistically significant (p < .05). Upon comparing the control groups with each other, it was seen that VF group had higher µTBS values than FLD group and the difference between the groups was found statistically significant (p < .05). The µTBS results and SEM images of the study showed that the use of SACs with universal adhesive systems provides a more effective bond strength.


Assuntos
Colagem Dentária/métodos , Cimentos Dentários/química , Adesivos Dentinários/química , Resinas Sintéticas/análise , Resinas Compostas , Análise do Estresse Dentário/métodos , Humanos , Microscopia Eletrônica de Varredura , Dente Molar , Resistência à Tração
7.
Quintessence Int ; 50(2): 94-102, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30720021

RESUMO

OBJECTIVE: The objective of this study was to evaluate the influence of delayed light curing on a dual-cured composite resin on cuspal deflection, microleakage, and enamel cracks. METHOD AND MATERIALS: Forty-eight standardized Class 2 cavities were prepared in maxillary third molars and restored with a dual-cure composite resin (Core-X Flow) in bulk-fill technique. The samples were divided into four groups (n = 12) and either self-cured (1) or light cured immediately (2), with 1 minute (3) or 2 minutes of delay (4) after placement. Cuspal deflection was measured before preparation, 6 minutes after placement, after 24 hours, and after 120 days of storage and thermocycling. The margins of the restorations were examined under a stereomicroscope after 24 hours and 120 days. Samples were immersed in a 0.2% basic fuchsin solution for 24 hours at room temperature and then sectioned vertically and mesiodistally, and dye penetration and enamel cracks were recorded under a stereomicroscope using a scoring system. RESULTS: Six minutes after placement the cuspal deflections were between 20 ± 2.1 µm and 39.3 ± 1.9 µm. After 120 days the cuspal deflection in all groups was reduced to almost complete recovery, while the percentage of perfect margin decreased. Differences in microleakage, dye penetration, and enamel cracks were observed between different locations but not between the groups. Statistical analysis did not show a correlation between cuspal deflection, margin quality, or enamel cracks. CONCLUSION: A short delay in light curing of a dual-cure composite resin could significantly reduce the initial cuspal deflection measured 6 minutes after light curing, thereby probably reducing the polymerization shrinkage stress. However, the curing mode did not significantly influence microleakage and enamel cracks.


Assuntos
Resinas Compostas/química , Infiltração Dentária , Restauração Dentária Permanente/métodos , Adesivos Dentinários/química , Cura Luminosa de Adesivos Dentários , Falha de Restauração Dentária , Humanos , Técnicas In Vitro , Teste de Materiais , Dente Serotino , Propriedades de Superfície , Fatores de Tempo
8.
Braz Oral Res ; 33: e012, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30758409

RESUMO

The aim of this study was to investigate the mechanical performance and the fracture behavior of endocrown restorations prepared using distinct restorative materials. A total of 42 sound molars with similar crown size and shape were cut at 2 mm above the cementoenamel junction and endodontically treated. They were categorized according to the restorative material used to fabricate endocrown restorations (n=7), namely, conventional composite (Filtek™ Z350 XT), bulk fill composite (Filtek™ Bulk Fill), conventional composite modeled using resin adhesives (SBMP: Scotchbond™ Multipurpose Adhesive; or SBU: Scotchbond™ Universal Adhesive), and IPS e.max lithium disilicate (Ivoclar Vivadent; positive control). Unprepared sound teeth were used as negative control. All endocrowns were bonded using a self-adhesive cement (Rely-X™ U200). The teeth were submitted to fatigue (Byocycle) and fracture (EMIC DL500) testing. Load-to-fracture (in N) and work-of-fracture (Wf, in J/m2) values were analyzed by ANOVA (p < 0.05). The endocrowns did not fracture or de-bond upon fatigue, showing similar load-to-fracture and work-of-fracture values, regardless of the restorative material (p > 0.05). The endocrowns fabricated by combining Z350 and SBMP had the least harsh fractures, in contrast to endocrowns prepared using Z350 only, which exhibited an equilibrium between repairable and irrepairable fractures. The e.max endocrowns exhibited more aggressive failures (root fracture) than other groups, resulting in higher rates of irrepairable fractures. In conclusion, dental practitioners may satisfactorily restore severely damaged nonvital teeth using the endocrown technique. Composite endocrowns prepared using resin adhesive as modeler liquid or using bulk fill material may result in less aggressive failures, thus providing a new material perspective for endocrown restorations.


Assuntos
Resinas Compostas/química , Coroas , Restauração Dentária Permanente/métodos , Adesivos Dentinários/química , Cimentos de Resina/química , Porcelana Dentária/química , Planejamento de Prótese Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Materiais Restauradores do Canal Radicular/química , Fraturas dos Dentes , Dente não Vital
9.
J Dent ; 82: 45-55, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30738850

RESUMO

OBJECTIVES: To evaluate the effect of addition of zinc oxide and copper nanoparticles (ZnO/CuNp) into universal adhesives, on antimicrobial activity (AMA), cytotoxicity (CTX), water sorption (WS) and solubility (SO), microhardness (MH) and in vitro degree of conversion (DC), as well as resin-dentin microtensile bond strength (µTBS), nanoleakage (NL) and in situ DC. METHODS: ZnO/CuNp (0% [control]; 5/0.1 and 5/0.2 wt%) were added in Prime&Bond Active (PBA) and Ambar Universal (AMB). The AMA was evaluated against Streptococcus mutans. For CTX, Saos-2 cell-line was used. For WS and SO, specimens were tested for 28d. For MH, specimens were tested after 24 h and 28d and for in vitro DC, specimens were evaluated after 24 h. After, the adhesives were applied to flat dentine surfaces, composite resin build-ups, specimens were sectioned to obtain resin-dentine sticks. It was evaluated in µTBS, NL and in situ DC after 24 h of water storage. ANOVA and Tukey's test were applied (α = 0.05). RESULTS: The addition of 5/0.2 ZnO/CuNp increase AMA and WS, but decrease the SO when compared to control (p < 0.05). The CTX and µTBS were maintaining with adhesive-containing ZnO/CuNp (p > 0.05). MH, in vitro DC and in situ DC was significant increase (AMB) or maintaining (PBA) with ZnO/CuNp addition. However, significantly lower NL was observed for ZnO/CuNp groups (p < 0.05). CONCLUSIONS: The addition of ZnO/CuNp in the tested concentrations in universal adhesive systems may be an alternative to provide antimicrobial activity and improves the integrity of the hybrid layer, without jeopardizing biological, adhesives and mechanical properties. SIGNIFICANCE: This is the first study that demonstrates that the addition of zinc oxide and copper nanoparticles in concentrations up to 5/0.2 wt% in two universal adhesive systems is a feasible approach and may be an alternative to adhesive interfaces with antimicrobial properties and less defects in the resin-dentin interface.


Assuntos
Cobre , Colagem Dentária , Infiltração Dentária , Adesivos Dentinários , Nanopartículas , Zinco , Cobre/química , Cimentos Dentários/química , Dentina , Adesivos Dentinários/química , Adesivos Dentinários/metabolismo , Humanos , Teste de Materiais , Nanopartículas/química , Cimentos de Resina , Resistência à Tração , Zinco/química
10.
Molecules ; 24(3)2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30717140

RESUMO

There is no consensus on the antibacterial activity of dentin bonding systems (DBS). Many study models have been used to evaluate the antimicrobial activity of dental materials. In this study, a novel detection method, flow cytometry, was introduced. It allows for evaluation of the antibacterial activity of DBS, based on assessment of the disruption of the bacterial physical membrane induced by DBS. The aim of the study was to evaluate the antibacterial properties of selected dentin bonding systems against Streptococcus mutans. The highest antibacterial activity against S. mutans was observed for Adhese Universal (99.68% dead cells) and was comparable to that of Prime&Bond Universal, OptiBond Universal, or Clearfil Universal Bond Quick (p > 0.05). The lowest activity of all tested systems was displayed by the multi-mode adhesive, Universal Bond (12.68% dead bacteria cells), followed by the self-etch adhesive, OptiBond FL (15.58% dead bacteria cells). The present study showed that in the case of two-component DBS, the primer exhibited higher antimicrobial activity than the adhesive (or bond) itself.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Adesivos Dentinários/farmacologia , Streptococcus mutans/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/classificação , Biofilmes/crescimento & desenvolvimento , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Adesivos Dentinários/química , Adesivos Dentinários/classificação , Relação Dose-Resposta a Droga , Citometria de Fluxo , Humanos , Teste de Materiais , Testes de Sensibilidade Microbiana , Streptococcus mutans/genética , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/metabolismo
11.
J Appl Oral Sci ; 27: e20180111, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30624464

RESUMO

OBJECTIVES: Several anti-proteolytic dentin therapies are being exhaustively studied in an attempt to reduce dentin bond degradation and improve clinical performance and longevity of adhesive restorations. This study assessed the effect of epigallocatechin-3-gallate (EGCG) on long-term bond strength when incorporated into adhesives. MATERIAL AND METHODS: Adhesive systems were formulated with EGCG concentrations of 0 wt%: (no EGCG; control); 0.5 wt% EGCG; 1.0 wt% EGCG, and 1.5 wt% EGCG. Flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), compressive strength (CS), degree of conversion (DC), polymerization shrinkage (PS), percentage of water sorption (%WS), percentage of water solubility (%WL) and cytotoxicity properties were tested. Dentin microtensile bond strength (µTBS) was evaluated after 24 h and again after 6 months of water storage. The adhesive interface was analyzed using scanning electron microscopy (SEM). RESULTS: No significant differences were found among the groups in terms of FS, ME, MR, CS and PS. EGCG-doped adhesives increased the DC relative to the control group. EGCG concentrations of 1.0 wt% and 0.5 wt% decreased the WS of adhesives. WL decreased in all cases in which EGCG was added to adhesives, regardless of the concentration. EGCG concentrations of 1.0 wt% and 0.5 wt% reduced cytotoxicity. EGCG concentrations of 1.0 wt% and 0.5 wt% preserved µTBS after 6 months of storage, while 1.5 wt% EGCG significantly decreased µTBS. SEM: the integrity of the hybrid layer was maintained in the 0.5 wt% and 1.0 wt% EGCG groups. CONCLUSION: EGCG concentrations of 1.0 wt% and 0.5 wt% showed better biological and mechanical performance, preserved bond strength and adhesive interface, and reduced cytotoxicity.


Assuntos
Bis-Fenol A-Glicidil Metacrilato/química , Catequina/análogos & derivados , Adesivos Dentinários/química , Metacrilatos/química , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato/toxicidade , Cânfora/análogos & derivados , Cânfora/química , Catequina/química , Catequina/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Força Compressiva , Dentina/química , Dentina/efeitos dos fármacos , Adesivos Dentinários/toxicidade , Módulo de Elasticidade , Fibroblastos/efeitos dos fármacos , Resistência à Flexão , Humanos , Teste de Materiais , Metacrilatos/toxicidade , Microscopia Eletrônica de Varredura , Polimerização , Valores de Referência , Reprodutibilidade dos Testes , Solubilidade , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo , Água/química
12.
Gen Dent ; 67(1): 28-31, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30644827

RESUMO

This study evaluated the effect of aging on the microtensile bond strength (µTBS) between composite resin and human dentin bleached with 35% hydrogen peroxide (HP) or 10% carbamide peroxide (CP). Thirty intact extracted third molars were selected for the study. After the dentin surface was exposed, the smear layer was abraded with silicon carbide paper to ensure standardization. The teeth were randomly divided into 3 groups: 1 (G1), no treatment (control); 2 (G2), dentin bleached with CP (at-home bleaching); and 3 (G3), dentin bleached with HP (in-office bleaching). G2 and G3 were bleached according to the manufacturers' instructions and stored in distilled water for 21 days. The teeth in all 3 groups were then bonded with a dental bonding agent and nanohybrid composite resin. Each tooth was sectioned and divided into groups to allow evaluations at 3 time periods: 24 hours, 6 months, and 12 months. The specimens were stored in distilled water at 37°C ± 1°C until use. The µTBS of the specimens was tested on a universal testing machine. Fracture mode analysis was performed with a stereoscopic loupe. The data were analyzed statistically by 2-way analyses of variance and Tukey tests. After 24 hours, G3 had a significantly lower mean [SD] µTBS value (20.00 [5.67] MPa) than G1 (31.14 [8.83] MPa), but their means were statistically similar at 6 months (29.42 [7.72] MPa vs 22.97 [7.48] MPa, respectively). Tukey tests revealed that there was no statistically significant change in µTBS over time for G2 or G3. After 12 months of aging, only G1 specimens showed statistically lower µTBS values compared with the 24-hour time period (P < 0.05). Based on the results, the durability of the bond between composite resin and dentin is not affected by the choice of bleaching treatment.


Assuntos
Colagem Dentária , Adesivos Dentinários/química , Dentina/química , Clareamento Dental , Resinas Compostas , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à Tração
13.
Dent Mater J ; 38(1): 101-106, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30381633

RESUMO

This study evaluates the effects of various agitation methods on the adhesive layer formation of a new HEMA-free universal dentin adhesive. The µTBS of the universal adhesive, G-Premio BOND in the self-etch mode was evaluated using three agitation methods [passive agitation (PA), active agitation (AA), ultrasonic agitation (UA)], with and without aging treatment. Two-way analysis of variance revealed that aging treatment was not a statistically significant factor. Tukey's HSD test showed significant differences based on the application method, UA>AA>PA. TEM images of the PA group revealed multiple water blisters in the adhesive layers; AA and UA groups presented significantly less or no blisters within the adhesive layers; thus, AA and UA groups exhibited better bonding performance for the HEMA-free universal adhesive. It is assumed that the entrap ped blisters can be reduced with the active application of dentin adhesive, and thus improving the bonding performance.


Assuntos
Resinas Compostas/química , Adesivos Dentinários/química , Humanos , Técnicas In Vitro , Teste de Materiais , Metacrilatos , Microscopia Eletrônica de Transmissão , Dente Serotino , Propriedades de Superfície , Resistência à Tração , Ultrassom , Vibração
14.
Acta Biomater ; 83: 140-152, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30414487

RESUMO

Commercially available dental adhesives fail to chemically unite the demineralized collagen matrix with resinous materials within the resin-dentin interface. Sub-micron separations between the collagen fibrils and polymerized resin provide the backdrop for bond deterioration. Here, novel isocyanate-terminated urethane methacrylate precursors (UMP) were synthesized with the capacity to bond chemically to dentin collagen via covalent and hydrogen bonds. Collagen grafted with UMP also copolymerized with other methacrylate resin monomers, thereby producing a monoblock of chemically-linked biocomposite. The viscosity, degree of conversion and biocompatibility of UMP are comparable with commercially available resin monomers. An experimental adhesive containing 40% UMP demonstrated co-polymerization capability, good infiltration capacity and achieved higher immediate bond strength to dentin than the control commercially available adhesive. Improvement of dentin bonding by incorporation of UMP into dentin adhesives justifies future evaluation of the potential of these UMP-based adhesives in extending the longevity of resin-dentin bonds. STATEMENT OF SIGNIFICANCE: Composite-adhesive restorations have become an indispensable treatment modality in contemporary restorative dentistry. While the inability of these adhesives to bond chemically with collagen undermines the bond quality. This study describes a novel isocyanate-terminated urethane multi methacrylate precursors (UMP) which can bridge dentinal matrix collagen with adhesive resin by covalent and hydrogen bonds. Furthermore, an experimental UMP-based adhesive shows better co-polymerization capability, good infiltration capacity and higher immediate bond strength than the putatively effective adhesive Single Bond 2. The new chemical bonding mechanism based on UMP would theoretically produce more stable bonding interface that are more resistant to degradation.


Assuntos
Colágeno/química , Polpa Dentária/metabolismo , Adesivos Dentinários , Dentina/química , Células-Tronco/metabolismo , Uretana , Polpa Dentária/citologia , Adesivos Dentinários/química , Adesivos Dentinários/farmacologia , Humanos , Teste de Materiais , Células-Tronco/citologia , Uretana/análogos & derivados , Uretana/química , Uretana/farmacologia
15.
Eur J Oral Sci ; 127(2): 162-169, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30536451

RESUMO

The purpose of this study was to evaluate whether surface wetness would influence the bonding effectiveness of universal adhesives in etch-and-rinse mode. All-Bond Universal (AB), G-Premio Bond (GP), Prime & Bond Active (PB), and Scotchbond Universal Adhesive (SU) were evaluated. Initial bond strengths and bond-fatigue strengths of universal adhesives to both wet and dry enamel and dentin in etch-and-rinse mode were determined. Scanning electron microscopy observations of the adhesive interfaces were also conducted. The bond-fatigue durability of universal adhesive to enamel in etch-and-rinse mode was influenced by the surface wetness, unlike that to dentin. The bond fatigue durability of AB and GP to dentin in etch-and-rinse mode was different depending on the surface wetness, unlike that of PB and SU. The thicknesses of the adhesive or hybrid layer of resin-dentin interfaces were not influenced by the surface wetness, but the length of resin tags in the wet group was longer than in the dry group. Some universal adhesives with the addition of specific components and optimization of water content can achieve stable bonds regardless of surface wetness, but the surface wetness of dentin is still a significant factor for universal adhesive bonding in etch-and rinse mode, unlike that of enamel.


Assuntos
Condicionamento Ácido do Dente/métodos , Adesivos/química , Colagem Dentária/métodos , Materiais Dentários/química , Adesivos Dentinários/química , Dentina , Propriedades de Superfície , Cimentos Dentários , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina/química
16.
J Dent Res ; 98(2): 186-193, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30326766

RESUMO

Instability of resin-dentin bonds is the Achilles' heel of adhesive dentistry. To address this problem, a chelate-and-rinse extrafibrillar dentin demineralization strategy has been developed that keeps intrafibrillar minerals within collagen fibrils intact to prevent activation of endogenous proteases that are responsible for collagen degradation within hybrid layers. The objective of the present study was to evaluate the potential of using chitosan >40 kDa as an antimicrobial extrafibrillar dentin-chelating agent to enhance bond durability. Transmission electron microscopy provided evidence for retention of intrafibrillar minerals and smear plugs in dentin conditioned with 1 wt% chitosan. Analyzed by Kruskal-Wallis analysis of variance, Dunn's statistic, and separate Mann-Whitney tests, tensile bond strengths to wet- and dry-bonded dentin indicated that chelating dentin with chitosan for 60 s prior to bonding did not result in a significant decline in resin-dentin bond strength when compared with that of phosphoric acid etching ( P > 0.05). Gelatinolytic activity within the hybrid layers was examined via in situ zymography after 24-h storage or after thermomechanical cycling and analyzed with 3-factor analysis of variance. After 24 h, enzymatic activity was detected only within completely demineralized phosphoric acid-etched dentin, with values derived from dry bonding significantly higher than those derived from wet bonding ( P < 0.05). Negligible fluorescence was detected within hybrid layers when dentin was conditioned with chitosan, even after thermomechanical cycling, as compared with the controls. Reduction in water permeability in chitosan-conditioned dentin, attributed to smear plug retention, also fostered long-term bond stability. Antibacterial testing performed with live/dead staining indicated that the acetic acid-solubilized chitosan possessed antibacterial activities against 3 single-species biofilms: Streptococcus mutans, Actinomyces naeslundii, and Enterococcus faecalis. Taken together, the new chitosan-based extrafibrillar demineralization strategy retains intrafibrillar minerals, reduces endogenous protease-initiated collagen degradation, prevents water permeation within hybrid layers, and kills bacteria on dentin surfaces, which are crucial factors for enhancing resin-dentin bond durability.


Assuntos
Anti-Infecciosos/farmacologia , Quitosana , Colagem Dentária , Adesivos Dentinários/química , Dentina , Cimentos de Resina/química , Desmineralização do Dente , Humanos , Teste de Materiais , Metaloproteinases da Matriz , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Resistência à Tração
17.
Dent Mater J ; 38(1): 107-113, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30298858

RESUMO

Tribochemical silica coating (TSC) is commonly used to pretreat zirconia surfaces prior to luting. Although many studies demonstrate an adhesion-promoting effect of TSC on zirconia, its actual interaction mechanism has not been fully elucidated. We therefore characterized the ultrastructure of TSC-treated zirconia and tested shear-bond strength. STEM/EDS disclosed a micro-roughened zirconia surface partially covered with fused Al and Si, while residual unfused silica particles could also still be detected. TSC-treated zirconia having received the solely silane primer exhibited a significantly lower shear-bond strength than zirconia on which the combined 10-MDP/silane primer was applied. SEM fracture analysis revealed residual silica particles on both the zirconia and cement sides. Correlative ultrastructural and chemical surface characterization revealed that TSC deposited an inhomogeneous silica layer on the zirconia surface, which explains why the solely silane coupling agent was less effective than the combined 10-MDP/silane ceramic primer for bonding to zirconia pretreated by TSC.


Assuntos
Colagem Dentária/métodos , Materiais Dentários/química , Adesivos Dentinários/química , Cimentos de Resina/química , Dióxido de Silício/química , Zircônio/química , Óxido de Alumínio/química , Materiais Revestidos Biocompatíveis/farmacologia , Cimentos Dentários , Teste de Materiais , Metacrilatos , Microscopia Eletrônica , Resistência ao Cisalhamento , Propriedades de Superfície
18.
Dent Mater J ; 38(1): 75-85, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30298860

RESUMO

This in vitro study aimed to evaluate the effect of two different polymer-based CAD/CAM materials; resin-nano ceramic (Lava Ultimate [LVU]) and composite (CERASMART [CS]), their different surface pre-treatments, and use of different resin cements on the µTBS of adhesively bonded CAD/CAM onlays to dentin. CAD/CAM materials were cut into slabs and divided into five groups according to the surface pre-treatments applied: Silane Primer, OptiBond XTR adhesive, Silane Primer+OptiBond XTR adhesive, Single Bond Universal (SBU), and RelyX Ceramic Primer+SBU. The LVU and CS specimens were bonded to the mid-coronal dentin of 50 non-carious human molars using NX3 resin cement with OptiBond XTR or RelyX Ultimate with SBU. µTBS was evaluated after 5,000 thermocycling and analysed with three-way-ANOVA and post-hoc Tukey's tests (p<0.05). The µTBS was significantly influenced by the type of CAD/CAM material (p<0.0001) surface pre-treatments (p<0.05) and resin cements (p<0.05). Regardless of the pre-treatments and resin cements, bonding of the composite CAD/CAM material to dentin was higher than the resin nano-ceramic material.


Assuntos
Resinas Compostas/química , Desenho Assistido por Computador , Adesivos Dentinários/química , Colagem Dentária , Humanos , Técnicas In Vitro , Teste de Materiais , Dente Molar , Polímeros/química , Silanos/química , Propriedades de Superfície , Resistência à Tração
19.
Oper Dent ; 44(1): 42-53, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29856702

RESUMO

OBJECTIVE:: The purpose of this study was to evaluate the effect of reduced application times of universal adhesives on enamel bond fatigue and surface morphology of the treated enamel with constant force atomic force microscopy (AFM). METHODS:: Four universal adhesives-Adhese Universal (AU), Clearfil Universal Bond Quick (CU), G-Premio Bond (GP), and Scotchbond Universal Adhesive (SU)-were evaluated in a laboratory for their ability to adhesively bond resin composite to enamel. Shear bond strengths were initially determined using 15 specimens per test group for each adhesive. Shear fatigue strengths were then determined using 20 specimens per test group for each the adhesives. The fatigue specimens were loaded using a sine wave at a frequency of 20 Hz for 50,000 cycles or until failure occurred. AFM observations, surface Ra roughness measurements, and geometric surface area evaluations of enamel surface treated with the adhesive agents were also conducted. RESULTS:: A strong relationship was found between the initial shear bond strength and shear fatigue strength for enamel surface Ra roughness but not for geometric surface area. The initial shear bond strength and shear fatigue strength of CU and GP were not influenced by different application times, unlike those of AU and SU. While the surface area of enamel treated with the adhesive agents was not significantly influenced by different application times and type of adhesive, surface Ra roughness of the enamel in the AU and SU groups significantly increased with increasing application time, unlike CU and GP. CONCLUSIONS:: The results of this study suggest that universal adhesives, used with reduced application times, have adequate Ra surface roughness to provide sufficient resistance to enamel bond fatigue at application times from <1 second to 20 seconds, while the geometric surface area of adhesive-treated enamel did not show any significant changes at these different application times.


Assuntos
Colagem Dentária/métodos , Adesivos Dentinários/química , Cimentos de Resina/química , Resinas Acrílicas , Teste de Materiais , Metacrilatos , Microscopia de Força Atômica , Propriedades de Superfície , Fatores de Tempo
20.
J Prosthodont ; 28(1): e222-e228, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28872730

RESUMO

PURPOSE: To evaluate microleakage in roots restored with fiber posts cemented using three different luting cements, to measure the volume of voids/gaps within the obturated/postcemented root canals, and to examine whether microleakage and the volume of voids/gaps were correlated. MATERIALS AND METHODS: Thirty-six extracted human mandibular incisors were decoronated, and the root canals were obturated using gutta-percha and sealer in the experimental groups (n = 30). Six roots were used as controls. A standard post space was prepared, and an identically sized fiber post was cemented in each experimental specimen using one of three luting cements (Panavia F2.0, Bifix SE, GC FujiCEM; n = 10 each). The specimens were scanned using micro-computed tomography, and the volume of voids/gaps was determined. The specimens were then subjected to a fluid filtration assay to evaluate microleakage. RESULTS: The volume of voids/gaps was significantly lower in the GC FujiCEM group, and significantly less microleakage occurred in the Bifix SE group compared with other groups (both p < 0.001). A significant correlation between the volume of voids/gaps and leakage was found only in the Panavia F2.0 group (p = 0.003; r = 0.830). No such correlation was found in the analysis of all groups combined. CONCLUSIONS: The group with the greatest volume of voids/gaps (Bifix SE) showed the least microleakage, and the group with the smallest volume of voids/gaps (GC FujiCEM) showed the most microleakage. Panavia F2.0 ranked between and exhibited significant correlation.


Assuntos
Cimentação/métodos , Cimentos Dentários/química , Infiltração Dentária , Técnica para Retentor Intrarradicular , Materiais Restauradores do Canal Radicular/química , Colagem Dentária , Infiltração Dentária/prevenção & controle , Materiais Dentários/química , Cavidade Pulpar/diagnóstico por imagem , Adesivos Dentinários/química , Vidro , Cimentos de Ionômeros de Vidro/química , Guta-Percha , Humanos , Hidroxibenzoatos , Incisivo , Teste de Materiais , Nitrofuranos , Cimentos de Resina , Obturação do Canal Radicular , Tratamento do Canal Radicular/métodos , Microtomografia por Raio-X
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