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1.
J Contemp Dent Pract ; 21(1): 91-96, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381808

RESUMO

AIM: The aim of this study was to assess if the curing mode and the etching mode could affect the push-out bond strength of different post cementation systems using two universal adhesives. MATERIALS AND METHODS: A total of 100 single-rooted teeth were divided into Prime & Bond Elect (PBE), Prime & Bond Active (PBA), and Prime & Bond XP (PBXP) as a control. The PBE, PBA, and PBXP were used in the self-etch (SE) and etch and rinse (E&R) mode. Post cementation was performed using Core X flow used in dark-cure and in light-cure. Data were analyzed using the one-way ANOVA test and post hoc Bonferroni and Dunnet tests. The Student's t test was performed to find significance between two independent groups. RESULTS: Bond strength was significantly influenced by the adhesive strategies. The PBE and PBA obtained higher values when used in the SE mode (p < 0.001). Light-cured groups obtained significantly higher values (p < 0.001) compared to dark-cured groups. The post space region also had a significant effect on the bond strength; the apical third recorded lower values in all groups (p < 0.001). CONCLUSION: The PBA and PBE universal adhesives obtained higher PBS values when used in the SE mode and followed by the light-curing of resin cement. CLINICAL SIGNIFICANCE: Universal adhesives represent a good alternative to the conventional total-etch adhesive system for fiber post cementation. Since they perform better in SE, they would be recommendable in clinical practice, as they can be used with a simplified technique.


Assuntos
Colagem Dentária , Adesivos Dentinários , Cimentos Dentários , Dentina , Humanos , Cimentos de Resina
2.
J Contemp Dent Pract ; 21(2): 140-147, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381817

RESUMO

AIM: The aim of this study was to evaluate the effects of different concentrations of sodium ascorbate (SA), green tea (GT), and chamomile (CM) on the shear bond strength (SBS) of metal orthodontic brackets bonded to teeth bleached with 40% hydrogen peroxide (HP). MATERIALS AND METHODS: Ninety-four sound premolars were divided into eight groups: group I (control + no bleaching), group II (bleaching + immediate bonding), group III (bleaching + 10% SA), group IV (bleaching + 35% SA), group V (bleaching + 0.5% GT), group VI (bleaching + 1% GT), group VII (bleaching + 0.5% CM), and group VIII (bleaching + 1% CM). In groups III-VIII, teeth were treated with the antioxidants for 10 minutes after bleaching with 40% HP, but before bonding. All the specimens were bonded with the resilience adhesive, and the SBS was tested with a universal testing machine (Instron 5965). The cross-head speed to break the bond was 1 mm/minute. The adhesive remnant index (ARI) was tested under 50× magnification. One-way analysis of variance, Tukey's post hoc, and Chi-squared tests were used for analysis (p ≤ 0.05). RESULTS: The differences in SBS among the eight tested groups were highly significant (p < 0.001). Comparison of the eight groups using Tukey's post hoc test revealed significantly lower SBS (p < 0.001) in test groups II, III, IV, and VIII than in group I. Adhesive remnant index scores showed significant intergroup differences (p = 0.005). Most groups had a failure score of 1 (<50% of the bonding material adhering to the tooth), whereas groups II and VIII showed a failure score of 0 (no material adhering to the tooth). CONCLUSION: Bond strength can be enhanced by using 0.5% or 1% GT or 0.5% CM to allow bracket bonding immediately after bleaching. CLINICAL SIGNIFICANCE: The use of antioxidants would allow clinicians to bleach teeth before orthodontic treatment without delaying bonding.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Clareamento Dental , Antioxidantes , Análise do Estresse Dentário , Humanos
3.
J Prosthodont Res ; 64(3): 319-325, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32423658

RESUMO

PURPOSE: The purpose of this study was to evaluate the effectiveness of both a resin primer containing methyl methacrylate (MMA) and a silanizing agent on bonding to indirect resin composite blocks, using two types of build-up hybrid resin composites. METHODS: SHOFU BLOCK HC (Shofu) specimens were blasted with alumina, after which one of two surface treatments was applied: CERA RESIN BOND (Shofu, the Silane group) or HC primer (Shofu, the MMA group). Resin composites made using either Solidex Hardura (SDH, Shofu) or Ceramage Duo (CMD, Shofu) were built up and micro-tensile bond strength (µTBS) values were measured after storage in water for either 24h or 6 months (n=24 per group). The fracture surfaces after µTBS measurements and the resin block/build-up resin interfaces were observed by scanning electron microscopy (SEM). RESULTS: The bond strength of the Silane/SDH group significantly decreased after 6 months (p<0.001), whereas in the MMA group there was no significant loss after 24h or 6 months (p=0.99). In the CMD group, the bond strength after 6 months was significantly lowered in both the Silane group (p<0.001) and the MMA group (p<0.001), but the latter still showed greater adhesion. SEM images demonstrated that the matrix resin was partially destroyed at the fracture surfaces of the MMA group and fracture surface unevenness was observed. CONCLUSIONS: A primer containing MMA produced stronger bonding to CAD/CAM resin even after long-term aging compared to a silane treatment.


Assuntos
Colagem Dentária , Cimentos de Resina , Resinas Compostas , Desenho Assistido por Computador , Teste de Materiais , Microscopia Eletrônica de Varredura , Silanos , Propriedades de Superfície , Resistência à Tração
4.
Int J Prosthodont ; 33(3): 292-296, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320182

RESUMO

PURPOSE: To assess the 10-year clinical retention and survival rates of metal-ceramic (MC) and all-ceramic (AC) cantilever resin-bonded fixed dental prostheses (CRBFDPs). MATERIALS AND METHODS: Forty CRBFDPs constructed from either cobalt-chromium ceramic (MC group; n = 20) or glass-infiltrated alumina ceramic (AC group; n = 20) were placed in 40 patients between August 2007 and December 2009. After baseline recordings, the patients were followed up using modified United States Public Health Services (USPHS) criteria after 6 months and thereafter annually for 10 years. Data were statistically analyzed using Kaplan-Meier estimation with log-rank (Mantel-Cox) test. RESULTS: The 10-year clinical retention rate was 95.0% in the MC group and 70% in the AC group. The difference was statistically significant (P = .02, log-rank test). Three all-ceramic CRBFDPs fractured at 6, 12, and 84 months after insertion. No statistically significant difference in survival rate was observed between the MC and AC groups over the 10 years of clinical observation (MC: 100%; AC: 85%; P = .075) (Kaplan-Meier method, confidence interval = 92.5% to 97.5%). CONCLUSION: Although glass-infiltrated alumina ceramic anterior CRBFDPs exhibited a lower clinical retention rate compared to metal-ceramic CRBFDPs, the debonded prostheses were recemented and continued in function over the observation period. Additionally, an acceptable 10-year clinical longevity was recorded.


Assuntos
Colagem Dentária , Planejamento de Dentadura , Cerâmica , Porcelana Dentária , Falha de Restauração Dentária , Seguimentos , Humanos , Estudos Retrospectivos
5.
J Adhes Dent ; 22(2): 149-159, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32322836

RESUMO

PURPOSE: To evaluate the influence of new air-abrasion powders with different silica concentrations (silica-coated aluminum oxide) and aging on the bond strength between composite cement and Y-TZP ceramic. MATERIALS AND METHODS: Ceramic slices (7 x 6.3 x 2 mm3) were randomly allocated into 8 groups (n = 20) considering different surface treatments (SiC: silica-coated aluminum oxide particles; AlOx: aluminum oxide particles; 7% Si and 20% Si: experimental powders consisting of 7% and 20% silica-coated of AlOx respectively) and aging (baseline: 24 h at 37°C in water; aged: 90 days at 37°C in water + 12,000 thermal cycles). A blinded researcher performed the air-abrasion procedure for 10 s (identical parameters for all groups). Composite resin cylinders (Ø = 3 mm) were cemented onto the silanized ceramic surfaces, light cured, and subjected to shear bond-strength testing (wire loop Ø = 0.5 mm). The topography of the powders and air-abraded surfaces was analyzed using SEM and atomic force microscopy (AFM). The elemental composition of the powders and air-abraded surfaces was analyzed with energy dispersive spectroscopy (EDS), and surface wetting of the air-abraded surfaces was also determined by contact-angle measurements. RESULTS: Under baseline conditions, all groups presented similar bond strengths, but only SiC and 7% Si yielded unaltered bond strength after aging. SiC and 7% Si presented lower contact angles. All groups presented similar surface topographies. The silica content was also similar among groups, except for AlOx. CONCLUSION: 7% Si and SiC presented similar bond strength and better bonding performance after aging than AlOx and 20% Si. A higher silica concentration was not able to promote stable adhesion of composite cement after aging.


Assuntos
Óxido de Alumínio , Colagem Dentária , Abrasão Dental por Ar , Cerâmica , Cimentos de Resina , Dióxido de Silício , Propriedades de Superfície , Ítrio , Zircônio
6.
J Adhes Dent ; 22(2): 161-172, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32322837

RESUMO

PURPOSE: To evaluate 1. the microtensile bond strength (µTBS) and in situ degree of conversion (DC) of adhesives applied using two bonding strategies after silver diamine fluoride (diamine) application on carious dentinal lesions, and 2. dentin etching patterns using SEM and energy dispersive x-ray spectroscopy. MATERIALS AND METHODS: Human molars were randomly divided into 12 experimental groups according to: 1. application of a silver diamine fluoride solution (carious dentinal lesion without silver diamine fluoride treatment [control], with 12% silver diamine fluoride [diamine 12%] or 38% silver diamine fluoride [diamine 38%]); 2. adhesives (Clearfil Universal Bond Quick [CUQ] and Scotchbond Universal [SBU]); 3. adhesive strategy (etch-and-rinse [ER] and self-etch [SE]). After restoration, the specimens were sectioned and submitted to µTBS testing. Sticks from each tooth were used for DC evaluation. To examine the changes induced by diamine before and after phosphoric acid treatment, SEM/EDX analysis was performed. Data from the µTBS and DC tests were analyzed using three-way ANOVA and Tukey's test (α = 0.05). RESULTS: Both concentrations of diamine resulted in a statistically significantly higher mean µTBS compared to the control (p < 0.0001). Diamine 38% showed a statistically significantly higher mean µTBS for both adhesives in SE mode compared to diamine 12% (p < 0.0001). The application of diamine to carious dentinal lesions did not significantly influence the mean DC values for either adhesive (p = 0.72). SBU showed a higher mean DC compared to CUQ (p = 0.03). After diamine treatment, there was an increase in the Ca peak intensity and the presence of residual silver ions mainly when diamine 38% was applied along with the SE approach. CONCLUSION: Independent of the adhesive application approach, the use of diamine may be a promising alternative to increase µTBS without jeopardizing the DC of the two adhesives in carious dentinal lesions.


Assuntos
Colagem Dentária , Cimentos Dentários , Dentina , Fluoretos Tópicos , Humanos , Compostos de Amônio Quaternário , Compostos de Prata , Resistência à Tração
7.
J Adhes Dent ; 22(2): 175-182, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32322838

RESUMO

PURPOSE: To evaluate the influence of hydrofluoric acid (HF) concentration and etching time on the microshear bond strength (µSBS) of RelyX Unicem 2 (3M Oral Care) to VITA Suprinity (Vita Zahnfabrik; zirconia-reinforced lithium-silicate glass ceramic: ZLS) and IPS e.max CAD (Ivoclar Vivadent; lithium-disilicate glass ceramic: LD). MATERIALS AND METHODS: Forty-eight bars each were fabricated of ZLS and LD with Cerec InLab MC-XL. For each material, 8 groups were formed with respect to etching time (20, 40, 60, 120 s) and HF concentration (4.9% and 9.5%). In each group, after etching and silanization, 15 cylindrical specimens of RelyX Unicem 2 were built up for µSBS testing with a special device. Data were analyzed using three-way ANOVA. Failure modes were assessed using an optical stereomicroscope, classified as adhesive, cohesive in resin or ceramic, or mixed. Failure modes were statistically analyzed using Fisher's Exact Test. One bar per group was prepared for SEM observation of the etched surface. RESULTS: ZLS showed significantly higher bond strengths than LD (p < 0.001). Etchant concentration was an influential factor with superior strengths after 4.9% HF etching (p = 0.009). Etching time did not significantly affect adhesion (p = 0.066). The material-etching interaction was statistically significant (p = 0.004). Particularly for ZLS, 4.9% HF etching obtained significantly higher bond strengths than did 9.5%. By using 4.9% HF, adhesion was significantly higher on ZLS than on LD. CONCLUSION: Material and HF concentration influenced the adhesion between RelyX Unicem 2 composite cement and lithium-silicate glass ceramics. Etching time was not an influential factor. The use of 4.9% HF for 20 s proved to be the most effective etching treatment of the intaglio surface.


Assuntos
Colagem Dentária , Cerâmica , Teste de Materiais , Propriedades de Superfície
8.
J Adhes Dent ; 22(2): 183-193, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32322839

RESUMO

PURPOSE: To determine the effect of Weibull analysis with censoring of cohesive failures on the evaluation of the effect of surface treatment and adhesive on the microtensile composite-composite bond strength. MATERIALS AND METHODS: Surfaces of Filtek Z250 (3M Oral Care) specimens aged in distilled water for five months at 37°C were ground with SiC paper P320 or air abraded with Al2O3 and built up with the same composite using Optibond FL (OPF, Kerr), Clearfil SE Bond (CSE, Kuraray Noritake) and Gluma Comfort Bond (GLU, Kulzer) adhesives. After sectioning and trimming, the specimens were stored at 37°C in distilled water for 24 h and then tested in a microtensile bond strength setup. Complete datasets of all strength data and adhesive datasets containing adhesively failed specimens were analyzed with a one-way Welch ANOVA at α = 0.05 and compared with the results of Weibull analysis applied on complete and adhesive datasets as well as complete datasets right censored for cohesive failures. Weibull shape (m) and scale (σo) parameters were estimated using the maximum likelihood method and used to calculate bond strength (σ0.10) at 10% probability of failure as a measure of system performance. The surface morphology was studied using light and scanning electron microscopy. RESULTS: While ANOVA indicated a significant effect of surface treatment and non-significant effect of the adhesive, the Weibull analysis results depended on bond strength characteristics and censoring. The scale parameter of the complete dataset indicating a significant effect of surface treatment for all adhesives became statistically non-significant for CSE after censoring. When this effect was evaluated by σ0.10, the non-significant effect of surface treatment for OPF and GLU became statistically significant due to censoring. The effect of the adhesive evaluated by the scale parameter was non-significant both for surfaces as well as complete and censored datasets. On the other hand, s0.10 suggested significant differences between adhesives on the ground surface for complete datasets which became statistically non-significant for the censored datasets. CONCLUSION: This study indicates that the results of statistical evaluation of bond strength can be affected not only by the experimental set-up and statistical model but also the bond strength characteristics and the manner in which the strengths of cohesively failed specimens are included in calculations.


Assuntos
Colagem Dentária , Condicionamento Ácido do Dente , Cimentos Dentários , Teste de Materiais
9.
J Adhes Dent ; 22(2): 195-204, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32322840

RESUMO

PURPOSE: To evaluate the effect of surface treatments and aging on the bond strength of composite cement to a novel CAD/CAM nanohybrid composite. MATERIALS AND METHODS: Microtensile bond strength (µTBS) of a dual-curing composite cement (Bifix QM; BQ) to three CAD/CAM restorative materials (Grandio [GR], Vita Enamic [VE], and Lava Ultimate [LU]) was evaluated after different surface treatments. The surfaces of specimens received the following treatments: control (no treatment), sandblasting (SB), SB + silane (Ceramic Bond; CB), hydrofluoric acid (HF), HF + CB, TiF4 2 wt/v%, TiF4 2 wt/v% + CB, TiF4 4 wt/v%, and TiF4 4 wt/v% + CB. Half of the specimens in each group were aged. Surface topography and surface roughness were evaluated. Statistical analysis was conducted using ANOVA and Tukey's test. The Weibull analysis was conducted on µTBS data of aged groups. RESULTS: The µTBS was significantly affected by the type of CAD/CAM material, type of treatment, and aging (p < 0.001). Silane application significantly improved the µTBS (p < 0.05). The µTBS decreased significantly with aging (5000 thermocycles) (p < 0.05). BQ cement resulted in the highest µTBS to GR treated with TiF4 2% wt/v + CB compared to the other groups (p < 0.05). Aged GR/BQ treated with TiF4 2% wt/v + CB had the highest predicted µTBS (19 MPa). CONCLUSION: TiF4 2% wt/v followed by silane application enhanced the adhesion of GR/BQ and LU/BQ systems. On the other hand, HF surface treatment followed by silane application improved the adhesion of the VE/BQ system.


Assuntos
Colagem Dentária , Cimentos de Resina , Cimentos Dentários , Teste de Materiais , Propriedades de Superfície
10.
Quintessence Int ; 51(5): 352-363, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32253389

RESUMO

OBJECTIVES: The purpose of the present prospective and randomized clinical trial was to evaluate the clinical performance of noncarious cervical lesions (NCCLs) restored with different adhesion strategies on the dental substrate. METHOD AND MATERIALS: An adhesive restorative system (Single Bond Universal/ Z350XT) with and without selective enamel conditioning was evaluated, as well as a resin-modified glass-ionomer cement (Vitremer), with and without pretreatment with ethylenediaminetetraacetic acid (EDTA). Two operators placed a total of 200 restorations in 50 patients (four restorations per patient). Data from decayed, missing, and filled teeth (DMFT), visible plaque, and gingival bleeding were collected prior to the restorations and at each evaluation time. All restorations were evaluated using the modified United States Public Health Service (USPHS) evaluation system at baseline, and at 6 and 12 months. Data were analyzed by the Friedman, chi-square, Cochran, Wilcoxon, and multiple logistic regression analysis tests (P ≤ .05). RESULTS: There was a gradual and significant increase in DMFT with a difference among the three evaluations (P ≤ .001). There was no difference for the Visible Plaque Index over time (P = .28); however, there was a significant reduction in the Gingival Bleeding Index between the baseline and the other evaluations (P ≤ .001). There was no statistically significant difference among groups and periods of evaluations (P > .05). Regarding logistic regression, the model as a whole was statistically significant (P = .034). CONCLUSION: The four different adhesion strategies in the NCCL restorations presented similar clinical performance after 1 year of follow-up.


Assuntos
Colagem Dentária , Restauração Dentária Permanente , Resinas Compostas , Adaptação Marginal Dentária , Seguimentos , Cimentos de Ionômeros de Vidro , Humanos , Estudos Prospectivos , Cimentos de Resina
11.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(2): 155-159, 2020 Apr 01.
Artigo em Chinês | MEDLINE | ID: mdl-32314888

RESUMO

OBJECTIVE: This work aimed to evaluate the effect of different surface treatments on the shear bond strength of resin nano ceramic to resin cement, thereby providing a theoretical basis for the improvement of clinical application. METHODS: A total of 150 specimens (10 mm×10 mm×3 mm) were milled from resin nano ceramic blocks (Lava Ultimate) using computer-aided design/computer aided manufacturing(CAD/CAM) technology. The specimens were randomly divided into five groups according to the surface treatment performed, as follows: control, sandblasted, sandblasted+silane, hydrofluoric acid, and hydrofluoric acid+silane groups. After the corresponding surface treatment, the specimens were cemented using Single Bond Universal Adhesive and RelyXTM Ultimate ClickerTM adhesive resin cement. All cemented specimens were placed in distilled water for 24 h and 30 days and subjected to a shear bond strength test in a universal testing machine. RESULTS: The surface treatment and water storage periods showed significant effects on bond strength. Surface treatment with sandblasted+silane showed the highest shear strength values among all tested groups, and the difference was statistically significant (P<0.05). A difference was observed between the control and hydrofluoric acid groups, and both had significantly difference compared with other groups (P<0.05). Sandblasted and hydrofluoric acid+silane groups were not statistically different, and both had significantly difference compared with other groups (P<0.05). CONCLUSIONS: The surface of resin nanoceramic treated by sand-blasted, sandblasted+silane, and hydrofluoric acid+silane can improve the bond strength. The sandblasted+silane group had the best the shear bond strength among the groups.


Assuntos
Colagem Dentária , Cimentos de Resina , Cerâmica , Porcelana Dentária , Análise do Estresse Dentário , Teste de Materiais , Resistência ao Cisalhamento , Silanos , Propriedades de Superfície
12.
Braz Oral Res ; 34: e020, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236317

RESUMO

This in vitro study aimed to assess the effects of different pretreatments used to adapt glass-fiber posts cemented to root canals with different resin cements, regarding porosity percentage and bond strength. Twelve bovine incisor roots were prepared with Largo drills. After post space preparation, the specimens were randomized into two types of pretreatment groups (n = 3): water-wet bonding and ethanol-wet bonding. After the post were cemented, the roots were stored in 100% humidity at room temperature for 7 days. The samples were scanned by microcomputed tomography (micro-CT). Images were reconstructed by NRecon software, and CTAn software was used to analyze the porosity percentage (%) at the luting interface. Evaluation of the push-out bond strength was performed by serially cutting the roots, and submitting the slices to testing. Additionally, the resin cement post-gel shrinkage values (%) were measured using the strain-gauge method (n = 10). Data were analyzed by two-way ANOVA, Tukey's test and Student's t test (a = 0.05). The roots prepared with ethanol-wet bonding using RelyX™ U200 had significantly lower porosity in the coronal and apical thirds (p < 0.05). The group prepared with ethanol-wet bonding using RelyX™ ARC presented better bond strength results in the coronal and apical thirds (p < 0.05). RelyX™ ARC (0.97%) produced a higher post-gel shrinkage value than RelyX™ U200 (0.77%). Canals pretreated with ethanol-wet bonding presented better outcomes in regard to porosity percentage and push-out bond strength.


Assuntos
Adesivos Dentinários/farmacologia , Etanol/farmacologia , Técnica para Retentor Intrarradicular , Cimentos de Resina/química , Raiz Dentária/efeitos dos fármacos , Animais , Bovinos , Colagem Dentária , Materiais Dentários/química , Cavidade Pulpar , Vidro , Teste de Materiais , Porosidade , Irrigantes do Canal Radicular/química , Microtomografia por Raio-X
13.
J Adhes Dent ; 22(2): 139-147, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32322835

RESUMO

PURPOSE: To evaluate the degree of conversion (DC%), water sorption (Sp), solubility (Sl), dentin bond strength (µTBS) (immediate and after 12 months of storage), and the antibacterial effect of an experimental adhesive containing different concentrations (%) of proanthocyanidin (PA): 0, 1%, 2%, 4.5%, and 6% (PA0, PA1%, PA2%, PA4.5% and PA6%, respectively). MATERIALS AND METHODS: DC% was measured by FT-IR and the Sp and Sl were determined based on the ISO 4049 specification. For µTBS, resin composite buildups were constructed incrementally and specimens (n = 8) were sectioned to obtain sticks (1 mm2). The µTBS was evaluated after 24 h and 12 months of water storage at 37°C. The failure mode was analyzed. The antibacterial effects were evaluated by analyzing the bacterial growth (S. mutans) (n = 5) and antibiofilm activity (n = 5) of the adhesives by spectrophotometry. RESULTS: The incorporation of PA did not affect the Sp, Sl, or DC%. Immediate µTBS was similar for all groups. After 12 months, PA4.5% presented significantly higher µTBS than PA0, while the other groups did not differ from PA0 and PA4.5%. Groups PA0 and PA1% underwent significant reduction in µTBS. In the experimental groups PA2%, PA4.5% and PA6%, µTBS was maintained after storage. All groups showed antibacterial activity. CONCLUSION: Incorporation of 2%, 4.5%, and 6% PA maintained the dentin µTBS after 12-month storage, without affecting the Sp, Sl, or DC% of experimental adhesives. PA4.5% presented higher µTBS values than PA0 after 12 months. The adhesive presented antibacterial effect irrespective of PA concentration.


Assuntos
Colagem Dentária , Proantocianidinas , Antibacterianos , Cimentos Dentários , Adesivos Dentinários , Teste de Materiais , Metacrilatos , Cimentos de Resina , Espectroscopia de Infravermelho com Transformada de Fourier
14.
J Appl Oral Sci ; 28: e20190499, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348441

RESUMO

Enzymatic degradation of the hybrid layer can be accelerated by the activation of dentin metalloproteinases (MMP) during the bonding procedure. MMP inhibitors may be used to contain this process. Objective To evaluate the degree of conversion (DC%), dentin bond strength (µTBS) (immediate and after 1 year of storage in water), and nanoleakage of an experimental (EXP) and a commercial (SB) adhesive system, containing different concentrations of the MMP inhibitor GM1489: 0, 1 µM, 5 µM and 10 µM. Methodology DC% was evaluated by FT-IR spectroscopy. Dentin bond strength was evaluated by µTBS test. Half of beams were submitted to the µTBS test after 24 h and the other half, after storage for 1 year. From each tooth and storage time, 2 beams were reserved for nanoleakage testing. Data were analyzed using ANOVA and Tukey's test to compare means (α=0.05). Results All adhesive systems maintained the µTBS after 1 year of storage. Groups with higher concentrations of inhibitor (5 µM and 10 µM) showed higher µTBS values than groups without inhibitor or with 1 µM. The nanoleakage values of all groups showed no increase after 1 year of storage and values were similar for SB and EXP groups, in both storage periods. The inhibitor did not affect the DC% of the EXP groups, but the SB5 and SB10 groups showed higher DC% values than those of SB0 and SB1. Conclusions The incorporation of GM1489 in the adhesive systems had no detrimental effect on DC%. The concentrations of 5 µM GM1489 for SB and 5 µM or 10 µM for EXP provided higher µTBS than groups without GM1489, in the evaluation after 1 year of storage; whereas the concentration of inhibitor did not affect adhesive systems nanoleakage.


Assuntos
Cimentos Dentários/química , Dentina/química , Inibidores de Metaloproteinases de Matriz/química , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Análise de Variância , Colagem Dentária/métodos , Corrosão Dentária/métodos , Infiltração Dentária , Dentina/efeitos dos fármacos , Humanos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo
15.
Oral Health Prev Dent ; 18(2): 145-152, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32238986

RESUMO

PURPOSE: To evaluate the microtensile bond strength of dentine/self-adhesive resin cement interface after several treatments on a dentine surface. MATERIALS AND METHODS: Twenty-eight human molars were selected and divided into four groups: no treatment (control (C)); 2% chlorhexidine digluconate (CHX); 25% polyacrylic acid (PA); and 23 ppm dispersive solution of silver nanoparticle (SN). Prepolymerised TPH resin composite (Dentsply) blocks were luted on the dentine surface using RelyX U200 self-adhesive resin cement (3M ESPE). Microtensile bond strength was measured (MPa) in a universal testing machine 24 h and 6 months after the bonding process. The fractured specimens were examined in an optical microscope and classified according to the fracture pattern. A representative sample of each group was observed by scanning electronic microscope. Data were submitted to analysis of variance (ANOVA) and Tukey's test to compare the mean among the groups (p <0.05). RESULTS: The highest microtensile bond strength values after 24 h were found for the PA group (13.34 ± 6.36 MPa), with no statistically significant difference for the C group (9.76 ± 3.11 Mpa). After 6 months, the highest microtensile bond strength values were found for the C group (9.09 ± 3.27 Mpa), with statistically significant difference only for the CHX group (2.94 ± 1.66 MPa). There was statistically significant difference only for the PA group when comparing the periods studied. Regardless of the surface treatment applied, there were more adhesive failures in both periods of time. CONCLUSION: Dentinal pretreatment with PA, as well as use of SN before the bonding procedure of self-adhesive resin cement to dentine, may be alternative bonding protocols.


Assuntos
Colagem Dentária , Nanopartículas Metálicas , Resinas Compostas , Cimentos Dentários , Análise do Estresse Dentário , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Cimentos de Resina , Prata , Propriedades de Superfície , Resistência à Tração
16.
Oral Health Prev Dent ; 18(2): 153-159, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32238987

RESUMO

PURPOSE: The air-particle-abrasion on zirconia in the gingival area of connectors and pontics in fixed partial dentures appears to increase fracture resistance. This study evaluated 'in situ' biofilm formation on the zirconia surface after different air-particle-abrasion protocols. MATERIALS AND METHODS: Ninety sintered blocks (5 × 5 × 2 mm) of yttrium partially stabilised zirconia (Y-TZP) were obtained and randomised among nine groups according to the factors 'type of particle' (Alumina 50 and 110 µm; Cojet and Rocatec) and 'pressure' (2.5 and 3.5 bar) used for sandblasting for 10 s. The surface roughness (Ra/Rz) was measured before and after sandblasting. For the in-situ analyses, custom-made removable intraoral devices n = 10 with one sample of each group attached to the buccal area were used by volunteers for 8 h at night. The specimens were analysed under confocal microscopy to quantify both biovolume and thickness of the initial biofilm formed. One-way analysis of variance (ANOVA) and Dunnett's tests were performed (5%). RESULTS: The roughness values ranged from 0.05 to 0.39 µm for Ra and from 0.35 to 2.11 µm for Rz, p = 0.00. Mean biofilm thickness ranged from 0.06 and 0.54 µm (p = 0.005), while the biovolume values were between 0.02 and 0.61 µm3/µm2 (p = 0.002). Values statistically significant for biofilm thickness and biovolume were found in groups sandblasted with Rocatec using 3.5 bar. CONCLUSION: In order to increase the fracture resistance of zirconia fixed partial dentures (FPDs), the air particle abrasion of zirconia with SiO2 (110 µm/3.5 bar), in the gingival area of connectors and pontics, should be avoided.


Assuntos
Colagem Dentária , Dióxido de Silício , Biofilmes , Materiais Dentários , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Zircônio
17.
Artigo em Inglês | MEDLINE | ID: mdl-32233200

RESUMO

The purpose of the present study was to (1) investigate the micro-shear bond strength and failure mode of a novel methacryloxydecyl-dihydrogen-phosphate (MDP) calcium-fluoride-releasing self-adhesive resin cement (TheraCem, BISCO) to a tooth structure (enamel and dentin) and to yttrium-stabilized zirconia after thermocycling, and to (2) compare the results with a universal non-MDP-containing self-adhesive resin cement (RelyX Unicem, 3M ESPE) as a control. Enamel and dentin specimens (20 discs each) were obtained by using a diamond saw (IsoMet 4000, Buehler) with copious water coolant. Twenty zirconia plates were obtained from IPS e.max ZirCAD blocks (Ivoclar Vivadent) and sintered in an inFire HTC speed high-temperature furnace (Dentsply Sirona). Resin-cement micro-cylinders were created on the bonded surface and filled with the tested cements (n = 10 for each surface/cement combination): Group A (control) used non-MDP-containing RelyX, whilegroup B (tested cement) used MDP-containing TheraCem MDP. Cements were left to self-cure for 5 minutes. All specimens were thermocycled for 5,000 cycles (THE-1100, SD Mechatronik). Micro-shear bond strength was measured using a universal testing machine, and debonded surfaces were examined for failure mode analysis with all morphologic and ultrastructure changes using a scanning electron microscope (Quanta 250 Field Emission Gun, FEI) attached with an energy dispersive x-ray (EDX) unit. The results were statistically analyzed. TheraCem had a slightly higher micro-shear bond strength (MPa) value than RelyX. Within enamel, TheraCem (6.46 ± 1.37 MPa) had a significantly higher mean µ-SBS value than RelyX (3.04 ± 0.99 MPa) (P = .002). Similarly, TheraCem in dentin (10.67 ± 1.27 MPa) had a significantly higher mean value than RelyX (6.46 ± 1.74 MPa) (P = .014). As for zirconia, TheraCem (39.76 ± 1.18 MPa) had a significantly higher mean µ-SBS value than RelyX (27.04 ± 1.92 MPa) (P < .001). Using MDP-containing calcium-fluoride-releasing self-adhesive resin cement (TheraCem) may improve bond strength to all tested substrates (enamel, dentin, and zirconia) and can be considered a promising cement for many clinicians. Further clinical studies are required to provide long-term clinical success data.


Assuntos
Colagem Dentária , Cimentos de Resina , Cálcio , Fluoreto de Cálcio , Cimentos Dentários , Análise do Estresse Dentário , Fluoretos , Teste de Materiais , Resistência ao Cisalhamento , Propriedades de Superfície , Zircônio
18.
Am J Dent ; 33(2): 64-68, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32259409

RESUMO

PURPOSE: To evaluate the effect of dentin biomodification on the long-term strength of sound and caries-affected (CA) dentin as a strategy to stabilize the dentin matrix. The biomodification strategy utilized a naturally occurring proanthocyanidin-rich Vitis vinifera grape seeds (Vv), and compared with glutaraldehyde (GD). METHODS: Dentin from sound and carious human molars were sectioned from mid-coronal dentin. The temperature denaturation (Td) was assessed using differential scanning calorimetry in sealed pans. The inhibitory effect of the agents on the activity of recombinant MMP-2 and -9 were assessed using colorimetric assay. The ultimate tensile strength (UTS) of demineralized dentin were determined 24 hours after treatment and after 12 months storage in simulated body fluid. Data were statistically analyzed using ANOVA and post-hoc tests ( α= 0.05). RESULTS: There was no statistically significant difference in the Td between sound and CA dentin (P= 0.140); however, Vv and GD significantly increased the Td of both substrates (P< 0.001), indicating formation of collagen cross-linking. The activity of MMP-2 and MMP-9 were reduced by Vv and GD in a concentration dependent manner. The UTS of dentin matrix was significantly affected by treatments and storage times (P< 0.001). After a 12-month period, a significant decrease in UTS was observed for sound and CA, with complete solubilization of the CA dentin matrix. Vv and GD stabilized the UTS of both dentin substrates (P< 0.05). Sound and CA dentin matrix were susceptible to degradation after the 12-month period. Degradation of dentin matrix due to endogenous proteases activity was more pronounced in CA dentin. Dentin biomodification strategies increased the thermal stability and enhanced the long-term mechanical properties of both sound and CA dentin matrix. CLINICAL SIGNIFICANCE: Carious dentin matrix is more susceptible to breakdown over time than sound dentin; however, the degradation process can be impaired by dentin biomodification. This biomimetic strategy increases the long-term tensile strength of the dentin matrix. Reinforcement of caries-affected dentin may increase longevity of adhesive interfaces.


Assuntos
Colagem Dentária , Cárie Dentária , Biomimética , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Dente Molar , Resistência à Tração
19.
J Indian Soc Pedod Prev Dent ; 38(1): 56-63, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32174630

RESUMO

Objective: The quest for ideal pulp capping materials has given rise to the development of newer materials such as light cure mineral trioxide aggregate (MTA). The bond strength of the pulp capping materials with overlying restoration is one among the several factors that are critical for the success of vital pulp therapy. Hence, we conducted this study to evaluate and compare the shear bond strength (SBS) of light cure MTA and light cure calcium hydroxide with nanofilled composite. Materials and Methods: Thirty acrylic blocks each with a central hole were prepared to uniform dimensions and randomly distributed into two equal groups. In Group I, light cure MTA, and in Group II, light cure calcium hydroxide was used as pulp capping materials. After the application of adhesive system, nanofilled composites were applied onto the pulp capping material using a cylindrical plastic matrix. The SBS was tested on a universal testing machine (Instrom 3366, UK) at a crosshead speed of 0.5 mm/min. The samples were examined under stereomicroscope and scanning electron microscope to analyze different modes of failure. Results: The results were statistically analyzed using independent sample t-test. Light cure MTA attained the mean SBS of 6.54 MPa and light cure calcium hydroxide attained the mean SBS of 6.56 MPa. There was no significant difference statistically in SBS of both the materials (P < 0.05). The modes of failure were predominantly mixed failure followed by cohesive failure within the restorative material in both Group I and II. Conclusion: The results of the study suggest that the SBS of light cure MTA and light cure calcium hydroxide is comparable. The modes of failure analyzed in both light cure MTA and light cure calcium hydroxide are not significantly different statistically. Hence, both materials can be successfully used as pulp capping material with nanofilled composite.


Assuntos
Hidróxido de Cálcio , Colagem Dentária , Compostos de Alumínio , Compostos de Cálcio , Resinas Compostas , Capeamento da Polpa Dentária , Combinação de Medicamentos , Microscopia Eletrônica de Varredura , Óxidos , Silicatos
20.
Braz Oral Res ; 34: e018, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32187304

RESUMO

The objective of this study was to evaluate the influence of hydrofluoric acid (HF) concentration, etching time, and application of phosphoric acid (PA) followed by neutralization with sodium bicarbonate on the bond strength between a feldspar ceramic and resin cement. Thus, 80 blocks (10 x 12 x 2 mm) of glass ceramic (VM - Vita Mark II - Vita Zahnfabrik) were made and randomly assigned to eight groups (n = 10) according to the factors: HF concentration (5 and 10%), etching time (60 and 120 s), and use of phosphoric acid (PA) (with and without). According to the experimental group, 37% PA (Condac, FGM) was applied after HF etching for 60s. Afterwards, samples were immersed in sodium bicarbonate for 1 min then in an ultrasonic bath in distilled water (5 min) for cleaning. After surface bonding treatment, cylinders (Ø = 2 mm; h = 2 mm) of dual resin cement (AllCem / FGM) were made in the center of each block. The samples were then stored in water (37ºC) for 90 days and submitted to the shear bond test (50 KgF, 1 mm/min). Failure analysis was performed by stereomicroscope and scanning electron microscopy. Data (MPa) were analyzed with 3-way ANOVA and Tukey's test. Only the factor "HF concentration" was significant (p = 0.02). Most failures were of cohesive in ceramic (40%) and mixed types (42.5%). The 10% HF resulted in higher shear bond strength value than the 5% HF. Surface cleaning with phosphoric acid followed by sodium bicarbonate and HF time (60 or 120 seconds) did not influence the resin bond strength to feldspar ceramic.


Assuntos
Silicatos de Alumínio/química , Colagem Dentária/métodos , Ácido Fluorídrico/química , Ácidos Fosfóricos/química , Compostos de Potássio/química , Análise de Variância , Porcelana Dentária/química , Teste de Materiais , Metacrilatos/química , Microscopia Eletrônica de Varredura , Valores de Referência , Reprodutibilidade dos Testes , Cimentos de Resina/química , Resistência ao Cisalhamento/efeitos dos fármacos , Silanos/química , Propriedades de Superfície , Fatores de Tempo
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