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1.
Am J Dent ; 34(2): 80-86, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33940664

RESUMO

PURPOSE: To evaluate and compare the effect on micro-tensile bond strength (µTBS) of a double layer application of three universal adhesives applied in self-etch mode to proximal dentin/cementum gingival margins of class II direct composite restorations, immediately and after 12 months water storage. METHODS: 66 molars with compound class II cavities, with gingival margin 1 mm below CEJ, were divided into three groups according to the universal adhesive used. The adhesives evaluated included All-Bond Universal (AB), Single Bond Universal (SB), and Prime&Bond Elect (PB). The groups were further subdivided according to adhesive application technique, either single layer or double layer application. All teeth were restored with the same nanofilled resin composite. µTBS were examined at a crosshead speed of 0.5 mm/minute after 24 hours or 12 months water storage. Fracture mode was assessed under stereomicroscope. Data were analyzed by two-way analysis of variance (ANOVA) followed by Tukey's post hoc test (P< 0.05). RESULTS: The double layer application µTBS values were significantly higher than single layer application in all groups. Regardless of the type of adhesive or application technique, all subgroups showed significantly decreased bond strength after aging. There were significant lower µTBS values for AB adhesive compared with the other two adhesives that demonstrated no significant differences between them. The double layer application technique was effective in enhancing µTBS values of all tested adhesives bonded to proximal dentin/cementum gingival margins compared to single layer application. Regardless of application technique, all tested adhesives were incapable of defying long-term water aging. CLINICAL SIGNIFICANCE: The double layer application technique may be recommended to enhance the bonding durability of universal adhesives to face challenges in bonding to dentin-cementum cervical margins.


Assuntos
Colagem Dentária , Adesivos Dentinários , Cimentos Dentários , Cemento Dentário , Dentina , Teste de Materiais , Cimentos de Resina
2.
Stomatologiia (Mosk) ; 100(2): 97-102, 2021.
Artigo em Russo | MEDLINE | ID: mdl-33874669

RESUMO

The analysis of modern scientific data on traditional and adhesive fixation of zirconia restorations, adhesion of various cements to zirconium dioxide, methods of surface preparation of ceramic restorations is presented. Micromechanical methods of preparation for cementation of the surface of a zirconia dental prosthesis are discussed in Part 1.


Assuntos
Colagem Dentária , Cimentos de Resina , Cerâmica , Cimentos Dentários , Porcelana Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Propriedades de Superfície , Zircônio
3.
Eur J Oral Sci ; 129(2): e12772, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33829577

RESUMO

This study aimed to investigate the effect of universal adhesive and silane pretreatment on the bond durability of metal brackets to dental glass ceramics. Eighty lithium disilicate glass ceramic specimens were randomly assigned to one of four groups (n = 20) defined by the pretreatment and adhesive used: (i) Adper Single Bond 2; (ii) silane + Adper Single Bond 2; (iii) Single Bond Universal; and (iv) silane +Single Bond Universal. Maxillary central incisor metal brackets were bonded on the ceramic surfaces with resin composite. A shear bond strength test was conducted after 24 h of water storage and after 10,000 thermocycles. Adhesive remnant index scoring and field-emission scanning electron microscopy were performed to determine adhesives remaining on the ceramic surfaces and the ceramic ultrastructure following bracket debonding, respectively. After 10,000 thermocycles, specimens treated with Single Bond Universal preserved an appropriate bond strength between brackets and glass ceramics and showed minimum ceramic surface damage following bracket debonding, which was not the case in the other three groups. The application of a silane-containing universal adhesive without silane pretreatment achieves adequate durability of the bond of metal brackets to dental glass ceramics and allows safe debonding, which may aid in optimizing the effectiveness for orthodontic treatment.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Cerâmica , Análise do Estresse Dentário , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento , Silanos , Propriedades de Superfície
4.
J Adhes Dent ; 23(2): 113-119, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33825425

RESUMO

PURPOSE: To evaluate the influence of different surface treatments of two CAD/CAM glass ceramics on surface topography, shear bond strength of composite cement, flexural strength, and elastic modulus. MATERIALS AND METHODS: Two ceramics were evaluated: lithium-disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS) glass ceramics. Glass ceramics were sintered and the surfaces were sandblasted (SBL) or etched with 9% hydrofluoric acid for 10 s (HF10), 20 s (HF20) or 30 s (HF30). The treated surfaces were analyzed using scanning electron microscopy (n = 3) to evaluate the etching pattern. For bond strength testing, ceramic samples were silanized after treatments and an adhesive was applied to the surface. Afterwards, a silicone mold was used to build composite-cement cylinders, which were tested after 24 h or one year of water storage (n = 10). Flexural strength and modulus were assessed using a 3-point bending test (n = 15). The data were subjected to statistical analysis at a pre-set α = 0.05. RESULTS: SBL and HF resulted in different surface topographies. Increased HF etching time influenced the surface dissolution level and exposition of crystals for LDS, while no effect of etching time was observed for ZLS. After one year, the bond strength to LDS significantly decreased, regardless of treatments. For ZLS, HF10 and HF20 showed stable bond strengths over time. SBL yielded the lowest bond strength for both ceramics and statistically significantly reduced the flexural strength of ZLS. The flexural strength and elastic modulus of ceramics were not affected by different etching times. CONCLUSION: Bonding stability depended on the glass ceramic and the pretreatment method employed. HF etching did not change the mechanical properties of the ceramics and is indicated as a ceramic treatment for bonding.


Assuntos
Colagem Dentária , Ácido Fluorídrico , Cerâmica , Porcelana Dentária , Resistência à Flexão , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície
5.
J Adhes Dent ; 23(2): 133-143, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33825427

RESUMO

PURPOSE: To evaluate the effect of different etching times of a self-etching ceramic primer on the microshear bond strength (µSBS) and topographic surface pattern of a lithium-disilicate glass-ceramic. MATERIALS AND METHODS: Ceramic slices were subjected to an in-lab simulation of CAD/CAM milling and randomly allocated to 10 groups (n = 35) considering two factors: "surface treatment" in 5 levels - one control group (5% hydrofluoric acid + silane application [HF5+SIL]), and 4 experimental groups using ceramic etching/primer (Monobond Etch & Prime, E&P) with different passive application times (40 s, 2 min, 5 min, or 10 min); and "aging" factor in 2 levels - short-term (after 24 h), or long-term (storage for 180 days + 12,000 thermal cycles). Composite cement cylinders were built and µSBS tests were run in a universal testing machine. The failure patterns were categorized, and complementary analyses with SEM and Atomic Force Microscopy (AFM) were performed. RESULTS: The groups showed statistically similar bond strengths in the short term (range 22.4 to 25.1 MPa). However, only the E&P 20s+40s (19.3 MPa) and E&P 20s+5min (21.5 MPa) groups maintained stable bond strength in the long term, and HF5+SIL (17.1 MPa) presented statistically significantly lower values than did E&P 20s+5min. The failure pattern was predominantly adhesive. The increased application time of the ceramic primer promoted greater dissolution of the glass matrix; thus, the E&P 20s+10min group presented the most complex surface characteristics in the fractal dimension analysis. CONCLUSION: The self-etching ceramic primer can be used as an alternative to classical conditioning with HF plus silane, promoting stable bond strength for etching times of 40 s or 5 min of passive application.


Assuntos
Colagem Dentária , Lítio , Cerâmica , Porcelana Dentária , Ácido Fluorídrico , Teste de Materiais , Cimentos de Resina , Silanos , Propriedades de Superfície
6.
J Adhes Dent ; 23(2): 145-158, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33825428

RESUMO

PURPOSE: To investigate the impact of pretreatment and conditioning on shear bond strength (SBS), surface free energy (SFE) and surface roughness (SR) between polyetheretherketone (PEEK) and cold-cured polymethylmethacrylate (PMMA). MATERIALS AND METHODS: PEEK substrates (Dentokeep PEEK Disc, nt-trading) were air abraded with Al2O3 particles of different grain sizes applied with varying pressure at 1) 0.2 MPa - 50 µm Al2O3; 2) 0.4 MPa - 50 µm Al2O3; 3) 0.2 MPa - 110 µm Al2O3; 4) 0.4 MPa - 110 µm Al2O3; or 5) without air abrasion (n = 172/group). Surface properties were quantified using SFE and SR (n = 10/group), and scanning electron microscope imaging (n = 2/group). Substrates were conditioned with a) Visio.link (VL, Bredent); b) Scotchbond Universal (SU, 3M Oral Care); c) Bonding Fluid (BF, Schütz Dental); or d) without conditioning (WC; n = 40/subgroup) and bonded to the polymer (Futura Jet, Schütz Dental). SBS and fracture types were determined before and after 10,000 thermal cycles (n = 20/subgroup). Univariate ANOVA, Kruskal-Wallis test, Mann-Whitney U-test, Kaplan-Meier survival estimates, and Weibull distribution were computed (p < 0.05). Ciba-Geigy tables and the chi-squared test were used to analyze fracture type distributions. RESULTS: An increase in particle size and pressure resulted in similar or increased SBS, Weibull characteristic strength, and Weibull moduli (p < 0.001 - 0.046). The lowest results were observed for the control group (without air abrasion), while pretreatment with 0.4 MPa - 110 µm Al2O3 presented the highest values (p < 0.001). In comparison with the other conditioning procedures, VL showed high (p < 0.001 - 0.03), and SU and WC low SBS (p < 0.001 - 0.006). Although it did not influence SFE, an increase in particle size and pressure led to an increased SR (p < 0.001). CONCLUSION: Pretreatment with 0.4 MPa - 110 µm Al2O3 can be recommended to increase bonding properties between PEEK and PMMA. Application of adhesives such as VL can enhance SBS further.


Assuntos
Colagem Dentária , Polimetil Metacrilato , Abrasão Dental por Ar , Análise do Estresse Dentário , Dentaduras , Cetonas , Teste de Materiais , Polietilenoglicóis , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície
7.
J Adhes Dent ; 23(2): 159-165, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33825429

RESUMO

PURPOSE: To evaluate the effect of inclusion of two dimethyl sulfoxide (DMSO) concentrations in simplified etch-and-rinse adhesives on dentin bonding durability after three years of water storage. MATERIALS AND METHODS: Forty-two caries-free third molars were divided into six experimental groups (n = 7) according to the following factors: 1) adhesive (Adper Single Bond 2 [SB], 3M Oral Care; Prime&Bond 2.1 [PB], Dentsply Sirona); 2) concentration of DMSO (control group: 0.0% DMSO; addition of 0.2% DMSO [0.2] and 2% DMSO [2.0]). After completing restoration, specimens were stored in water (37°C) for 24 h, sectioned into adhesive-dentin sticks (0.8 mm2), tested for microtensile bond strength (µTBS) at 0.5 mm/min, and examined for nanoleakage (NL) using SEM immediately thereafter or after three years of water storage. Data were subjected to a three-way repeated-measures ANOVA and Tukey's test (α = 0.05) for each property evaluated. RESULTS: After three years of water storage, for both adhesives, the incorporation of 2% DMSO maintained the µTBS when compared to immediate µTBS (p > 0.05). In general, SB resulted in a statistically significantly higher mean of µTBS compared to PB, independent of the DMSO concentration after water storage (p < 0.05). Furthermore, the amount of NL was lower and practically limited to the hybrid layer given the concentrations of 0.2% and 2% DMSO for both tested adhesives after three years. CONCLUSION: The incorporation of DMSO in simplified etch-and-rinse adhesives maintains the long-term stability of the dentin bond.


Assuntos
Colagem Dentária , Adesivos Dentinários , Dentina , Dimetil Sulfóxido , Teste de Materiais , Cimentos de Resina , Resistência à Tração , Água
8.
J Adhes Dent ; 23(2): 167-175, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33825430

RESUMO

PURPOSE: To investigate the effects of root canal irrigants, dentin surface treatment, and timing of the restoration on the microtensile bond strength (µTBS) of a universal adhesive to deep coronal dentin. MATERIALS AND METHODS: Ninety (90) intact molars were grouped according to the irrigation protocol: group 0 (saline, control group); group 1: 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) followed by 5.25% NaOCl; group 2: 18% etidronic acid (HEDP) + 5.25% NaOCl in a single mixture. Groups 1 and 2 were divided into 2 subgroups (n = = 10) according to the time of restoration: immediate (subgroup A) and after 7 days (subgroup B). Four other groups (n = 10) were created according to the dentin surface pretreatment and received an immediate restoration: group 3: 5.25% NaOCl - 17% EDTA and AH Plus Cleaner; group 4: 5.25% NaOCl - 17% EDTA and 100% ethanol; group 5: 5.25% NaOCl + 18% HEDP and AH Plus Cleaner; group 6: 5.25% NaOCl + 18% HEDP and 100% ethanol. µTBS testing was carried out for each subgroup and interfaces were analyzed through SEM. The µTBS was analyzed with Welch statistics and the post-hoc Games-Howell test for multiple comparisons (p < 0.05). RESULTS: Statistically significant differences were observed between test groups and control groups (p < 0.001), except for group 3 (p = 0.349). No significant differences were recorded between groups 1A (27.5 ± 8.7 MPa), 2A (32.6 ± 14.5 MPa) and 3 (27.3 ± 14.3 MPa). Group 6 (48.6 ± 11.6 MPa) exhibited the highest µTBS among all tested groups. For groups 1 and 2, significantly higher values were recorded for subgroups 1B (39.3 ± 7.6 MPa) and 2B (43.8 ± 8.3 MPa) compared to subgroups 1A (27.5 ± 8.7 MPa) and 2A (32.6 ± 14.5 MPa). CONCLUSION: When using NaOCl as root canal irrigant, it is advisable to delay the placement of a post-endodontic-treatment restoration.


Assuntos
Colagem Dentária , Cimentos Dentários , Cavidade Pulpar , Análise do Estresse Dentário , Dentina , Ácido Edético , Teste de Materiais , Irrigantes do Canal Radicular , Preparo de Canal Radicular , Hipoclorito de Sódio
9.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 56(4): 342-348, 2021 Apr 09.
Artigo em Chinês | MEDLINE | ID: mdl-33832035

RESUMO

Objective: To explore the effect of subpressure on the bonding strength of resin to polycrystalline particulates modified zirconia ceramic. Methods: One hundred and twenty pre-sintered zirconia discs were prepared and divided into the control group, the sandblasting group and the 30, 50, 70 s acid etching group (24 per group) by the random number table method. There was no additional treatment in the control group and sandblasting group before sinering. The 30, 50, and 70 s acid etching groups were immersed in HF for 30, 50, 70 s, respectively, and then they were placed into CaCl2 solution for 90 s and dipped in NaOH solution at 80 ℃ for 2 h. After sintering, the sandblasting group was subjected to sandblasting. The surface tomography and roughness were tested. According to whether subpressure was applied or not after the adhesives were applied, each group was randomly divided into two subgroups with a random number table: a subpressure subgroup and a normal pressure subgroup (12 per subgroup). Resin columns were bonded to these specimens. Shear bonding strength (SBS) test was conducted and the bonding interface, fracture surface and failure mode were analyzed. Results: The surface of control group was smooth, and its roughness was (0.24±0.11) µm. The rough surface was formed after sandblasting in the sandblasting group, and its roughness was (0.95±0.12) µm. The surface roughness of 30, 50, 70 s acid etching groups [(0.60±0.15), (1.04±0.11), (1.57±0.16) µm] increased as the HF immersion time prolonged, and the difference in surface roughness of zirconia specimens among each group was statistically significant (P<0.05). The SBS values between zirconia and resin of all the subpressure subgroups, namely: the control group, the sandblasting group, and the 30, 50, 70 s acid etching group [(13.56±1.19), (20.98±2.11), (17.37±2.44), (24.19±2.97), (21.36±2.16) MPa] were significantly stronger than those in the normal pressure subgroups, namely: the control group, sandblasting group, 30, 50, 70 s acid etching group [(10.74±0.93), (18.47±2.14), (14.81±1.54), (20.74±2.56), (17.75±2.54) MPa] (P<0.05). No obvious gaps and bubbles were observed in the bonding interfaces in subpressure subgroups. The proportion of mixed failure was significantly increased after applying subpressure (P<0.05). Conclusions: The subpressure can effectively enhance the bonding strength between the resin and polycrystalline particulates modified zirconia ceramic and improve the bonding effect.


Assuntos
Colagem Dentária , Cimentos de Resina , Cerâmica , Cimentos Dentários , Porcelana Dentária , Teste de Materiais , Microscopia Eletrônica de Varredura , Resistência ao Cisalhamento , Propriedades de Superfície , Zircônio
10.
J Orthod ; 48(1): 13-23, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33843329

RESUMO

OBJECTIVES: To assess the transfer accuracy of three-dimensional (3D) printed transfer trays and compare them with transfer trays made up of polyvinyl siloxane (PVS) for use in indirect bonding. DESIGN: This was a two-arm parallel prospective randomised controlled trial. SETTING: The trial was undertaken at the outpatient department of a dental college. PARTICIPANTS: A total of 30 patients (18 men, 12 women) were randomly allocated to two groups. METHODS: The inclusion criteria included patients with permanent and fully erupted dentition (age range = 17-24 years), Angles class I malocclusion with crowding <3 mm requiring non-extraction treatment, good oral hygiene and no previous history of orthodontic treatment. Blinding was applicable only for outcome assessment. Indirect bonding was performed by the primary investigator for both the groups. Digital images of the pre-transfer and post-transfer brackets were obtained by means of an intra-oral scanner and compared using software. Superimpositions of pre- and post-transfer images were done to determine the transfer error for linear and angular variables for all tooth types. RESULTS: A total of 600 teeth were bonded, 300 each for both groups. Statistically significant differences were observed in all dimension between the two groups, with 3D-printed trays being more accurate than PVS trays except in the vertical dimension (P < 0.05). The prevalence of clinically unacceptable transfer errors revealed that most of the transfer errors were in the vertical dimensions for 3D-printed trays. CONCLUSION: 3D-printed trays are more accurate than PVS trays except for transfers in vertical dimension.


Assuntos
Colagem Dentária , Má Oclusão de Angle Classe I , Braquetes Ortodônticos , Adolescente , Adulto , Modelos Dentários , Feminino , Humanos , Masculino , Estudos Prospectivos , Adulto Jovem
11.
Braz Dent J ; 32(1): 85-90, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33914007

RESUMO

This study evaluated the chemical composition and microhardness of human enamel treated with an Enamel Matrix Derivative (EMD) solution, and the bond strength between composite resin and this enamel. Thirty human enamel samples were randomly divided into three groups: Untouched Enamel (UE), Demineralized Enamel (DE) and Demineralized Enamel Treated with EMD (ET). DE and ET groups were subjected to acid challenge and ET treated with EMD (EMD was directly applied over conditioned enamel and left for 15 min). Samples from each group (n=4) had chemical composition assessed through to attenuated total reflectance Fourier transform infrared (ATR-FTIR). Knoop microhardness of enamel samples from each group (n=10) was measured. For the microshear bond strength, the samples were etched for 30 s, and the adhesive was applied and cured for 10 s. Two matrixes were placed on the samples, filled with Filtek Z350 XT composite and cured for 20 s, each. The matrix was removed, and the microshear bond strength of each group (n=10) was tested. Data were subjected to Kruskal-Wallis test (for microhardness), to analysis of variance and to Tukey's test (for microshear bond strength); (α=0.05). FTIR results have shown phosphate (hydroxyapatite indicator) in 900-1200 cm-1 bands in the UE and ET groups, which were different from the DE group. Microhardness and microshear analyses recorded higher statistical values for the UE and ET groups than for DE. EMD application to demineralized enamel seems to have remineralized the enamel; thus, the microhardness and bond strength was similar between UE and ET groups.


Assuntos
Colagem Dentária , Resinas Compostas , Cimentos Dentários , Esmalte Dentário , Dureza , Humanos , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento
12.
Gen Dent ; 69(3): 24-29, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33908874

RESUMO

This study evaluated the failure load and the shear bond strength of 4 block materials indicated for computer-aided design/computer-aided manufacturing (CAD/CAM) of dental veneers: lithium disilicate, feldspathic ceramic, polymer-infiltrated ceramic, and nanohybrid composite. The tested hypothesis was that the material that combined an elastic modulus similar to that of enamel with the highest bond strength values would present the highest failure load. From prefabricated CAD/CAM blocks, disc-shaped specimens (6.0 × 0.7 mm; n = 10) and cylinders (2.4 × 2.5 mm; n = 10) were fabricated for load-to-failure and shear bond strength tests, respectively. Materials were adhesively bonded to flattened bovine enamel surfaces, stored in distilled water at 37°C for 90 days, and subjected to thermocycling (2000 cycles of 5°C to 55°C). Discs of restorative material were bonded to enamel and subjected to an increasing load that was applied perpendicular to the bonding interface until catastrophic failure occurred. A chisel was used to apply an increasing load parallel to the adhesive interface between the enamel and a cylinder of restorative material to measure shear bond strength. Data were subjected to a Weibull analysis and 1-way analysis of variance followed by a Tukey post hoc test (α = 0.05). The type of restorative material significantly affected the (mean [SD]) failure load when bonded to enamel (P = 0.006): polymer-infiltrated ceramic (1167.9 [310.2] N) = feldspathic ceramic (1115.0 [382.0] N) = nanohybrid composite (1067.3 [251.0] N) > lithium disilicate (786.2 [304.5] N). The type of restorative material also significantly affected the (mean [SD]) bond strength to enamel (P < 0.001): lithium disilicate (32.81 [11.19] MPa) = polymer-infiltrated ceramic (27.04 [7.65] MPa) > feldspathic ceramic (21.11 [9.16] MPa) > nanohybrid composite (9.08 [3.66] MPa). The polymer-infiltrated ceramic presented the best performance when bonded to enamel.


Assuntos
Colagem Dentária , Cimentos de Resina , Animais , Bovinos , Cerâmica , Esmalte Dentário , Porcelana Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Resistência ao Cisalhamento , Propriedades de Superfície
13.
Oper Dent ; 46(1): 45-53, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33882136

RESUMO

CLINICAL RELEVANCE: High-viscosity glass-ionomer cements (HVGICs) used with atraumatic restorative treatment can be repaired with light- or self-cured adhesive systems; however, the repair bond strength of two-step, self-etching and one-step adhesives in the light-cure mode surpass one-step self-cure adhesives. Working on a feasible self-cure approach in the absence of such in rural areas as well as in war zones is of prime importance.


Assuntos
Tratamento Dentário Restaurador sem Trauma , Colagem Dentária , Resinas Compostas , Cimentos Dentários , Cimentos de Ionômeros de Vidro , Teste de Materiais , Cimentos de Resina , Viscosidade
14.
Oper Dent ; 46(1): 107-115, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33882140

RESUMO

CLINICAL RELEVANCE: Use of zirconia primers with a low pH and a high acidic monomer concentration should be employed in combination with dual-cure resin cements that are less sensitive to an acidic environment. Primers with lower 10-MDP concentrations attain better outcomes.


Assuntos
Colagem Dentária , Cimentos de Resina , Teste de Materiais , Metacrilatos , Resistência ao Cisalhamento , Propriedades de Superfície , Zircônio
15.
Oper Dent ; 46(1): E1-E10, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33882142

RESUMO

CLINICAL RELEVANCE: Carious and eroded dentin represent clinical challenges. The use of a universal bonding system, in a self-etching mode, associated with chlorhexidine (CHX) seems to not improve its longevity. This may be attributed to the competition for calcium between the bonding agent functional monomer and CHX.


Assuntos
Clorexidina , Colagem Dentária , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência à Tração
16.
Int J Prosthodont ; 34(2): 221-228, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33882568

RESUMO

PURPOSE: To investigate whether high-level irradiance and short light exposure times with light-emitting diode (LED) curing units could provide bond strength comparable to halogen lights for ceramic laminate veneers (CLVs). MATERIALS AND METHODS: A total of 160 extracted human maxillary central incisors were prepared to receive CLVs (lithium disilicate) in shades A1 and A3.5. CLVs were luted with light-curing (LC) and dual-curing (DC) resin cements using four protocols: 3 seconds in extra power mode, 8 seconds in high power mode, or 10 seconds in standard mode with an LED unit, or 40 seconds with a conventional halogen light from all aspects (n = 10). Following thermal cycles, shear bond strength test was performed with a universal testing machine. Data were analyzed using one-way analysis of variance and post hoc Tukey test. Failure modes were classified under a stereomicroscope, and data were analyzed using Pearson chi-square test (P = .050). RESULTS: According to the intragroup comparison of different irradiation protocols, the mean shear bond strength of the A1-LC-10 group was found to be significantly higher than that of the A1-LChalogen group (P = .026). Shear bond strength values of the A1-LC-10 group and A3.5-LC-10 group were significantly higher than that of the A3.5-DC-10 group (P = .003). The A3.5-DC-3, A3.5-LC-3, and A1-DC-8 groups revealed the significantly most adhesive failures, and the A1-LC-8 group revealed the most mixed failures (P < .001). CONCLUSION: Both light and dark ceramic shades with LC cement combination responded the best to the standard mode of 10-second exposure time with LED application. However, with conventional halogen light application, the highest bond strength values were obtained with DC cement and light ceramic shade combination.


Assuntos
Luzes de Cura Dentária , Colagem Dentária , Cerâmica , Análise do Estresse Dentário , Cimentos de Ionômeros de Vidro , Humanos , Cura Luminosa de Adesivos Dentários , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície
17.
Gen Dent ; 69(3): 52-56, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33908879

RESUMO

This study evaluated the effect of fiber post customization and laser application on the results of pull-out tests in endodontically treated teeth. Forty-eight bovine incisors were stored in aqueous 2% formaldehyde (pH 7.0) for 30 days. At the end of the storage period, the incisors were scraped with No. 11/12 periodontal curettes, rinsed with water and sodium bicarbonate, and stored in 0.9% saline solution for 7 days. Roots with similar shape and dimensions were selected and sectioned to a standard 17-mm length. Root canals were prepared and filled to a depth of 12 mm. The roots were divided into 4 groups (n = 12): 1, conventional fiber post and no laser application; 2, customized fiber post and no laser application; 3, conventional fiber post and laser application; and 4, customized fiber post and laser application. After removal of the obturation material for post space preparation, the canals were enlarged, and a laser beam was applied to the roots of teeth in groups 3 and 4 as an auxiliary disinfection procedure. After cementation of the posts, a pull-out test was performed using an axial tensile load at 0.5 mm/min in a universal testing machine. Analysis of variance and the Tukey test were used for statistical analysis of the results. The mean (SD) maximum tensile force was 10.18 (4.73) kgf in group 1, 38.89 (6.49) kgf in group 2, 27.74 (10.07) kgf in group 3, and 38.92 (6.89) kgf in group 4. These values were significantly higher in groups 2 and 4 than in group 1 (P < 0.05). The customization of fiber posts used for the restoration of pulpless teeth resulted in significantly (P < 0.05) greater pull-out test values, a thinner cement layer, and improved retention.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Dente não Vital , Animais , Bovinos , Cavidade Pulpar , Análise do Estresse Dentário , Vidro , Humanos , Lasers , Teste de Materiais , Cimentos de Resina
18.
Eur J Oral Sci ; 129(2): e12768, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33667032

RESUMO

This study aimed at determining the enamel bond durability of universal adhesives to intact enamel (IE) and ground enamel (GE) in different etching modes under thermal cycling (TC) and fatigue stresses. Two universal adhesives and a two-step self-etch adhesive were used. Enamel specimens were divided into four groups by treatment: (i) GE in etch-and-rinse, (ii) IE in etch-and-rinse, (iii) GE in self-etch, and (iv) IE in self-etch. Bonded specimens were subjected to TC, and then shear bond strengths (SBS) were conducted. SBS tests were also conducted after storage in 37°C water for 24 h (baseline). For shear fatigue strength (SFS) testing, bonded specimens were subjected to fatigue stress at a frequency of 10 Hz for 50,000 cycles. At baseline, all adhesives showed significantly higher SBS values with GE than IE in self-etch mode in contrast to in etch-and-rinse mode. After TC, the universal adhesives with IE showed lower SBS values than the baseline, regardless of the etching mode. Universal adhesives showed significantly lower SFS values with IE in etch-and-rinse, but not in self-etch mode. Phosphoric acid pre-etching or grinding of the aprismatic enamel may be helpful in establishing reliable initial and long-term bonds to enamel when using universal adhesives in self-etch mode.


Assuntos
Condicionamento Ácido do Dente , Colagem Dentária , Adesivos , Cimentos Dentários , Esmalte Dentário , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento
19.
Eur J Oral Sci ; 129(2): e12773, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33724583

RESUMO

This review compiles the literature on the antioxidants used after tooth bleaching with either low or high-concentrated carbamide and hydrogen peroxide to recover the bond strength. Antioxidants used in bleached teeth are mainly natural and non-enzymatic, except for catalase. Commonly, antioxidants are applied to remove any reactive oxygen species (ROS) residues left from bleaching gels, which adversely affect adhesive procedures, such as restorations or orthodontic brackets bonding. Even though sodium ascorbate, the most thoroughly investigated antioxidant, showed the most efficient bond strength recovery at 10% concentration, its performance depends on the type of solution and the application time. Natural extracts, such as proanthocyanidins and green tea, showed satisfactory results in the reversal of bond strength at 5% and 10% concentrations, respectively. Sodium ascorbyl phosphate, α-tocopherol, and catalase exhibited promising results, but further research is required. The adhesive system type plays an important role in the outcome of enamel bond strength after the antioxidant application. The postponement of either restorations or orthodontic brackets cementation following bleaching procedures seems to be efficiently replaced by antioxidant application prior to bonding procedures. However, the efficacy of using an antioxidant to recover bond strength depends on its type and application time.


Assuntos
Colagem Dentária , Clareamento Dental , Antioxidantes , Cimentos Dentários , Peróxidos , Resistência ao Cisalhamento , Ureia
20.
BMC Oral Health ; 21(1): 131, 2021 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-33740953

RESUMO

BACKGROUND: To evaluate the effect of surface treatments on the push-out bond strength of Biodentine (BD) and white mineral trioxide aggregate (WMTA) to fiber posts. METHODS: Two brands of fiber posts were used: Reblida post; RP and RelyX post; RX. Each type of post (n = 80/group) was divided into four groups (n = 20/group) and exposed to surface treatment as follows: Control (no treatment), sandblasting (SB), hydrofluoric acid (HF), and TiF4 4 wt/v%. Each group was further subdivided into two subgroups (n = 10/subgroup) based on the type of CSCs used as follows: Subgroup A: BD and Subgroup B: WMTA. Push-out bond strength of BD and WMTA to glass fiber posts was assessed. Data were statistically analyzed using three-way ANOVA and Tukey's test. A Weibull analysis was performed on the push-out bond strength data. RESULTS: BD showed higher bond strength than WMTA (P < 0.001). The push-out bond strength for posts treated with TiF4 4 wt/v% showed greater bond strength than the other surface treatments (P < 0.05). The BD/RP-TiF4 4 wt/v% showed the greater characteristic bond strength (σ0) (15.93) compared with the other groups. Surface treatments modified the surface topography of glass fiber posts. CONCLUSIONS: The BD/RP-TiF4 4 wt/v% showed greater bond strength compared with the other groups. The TiF4 4 wt/v% surface treatment enhanced the bond strength of BD and WMTA to glass fiber posts than the other treatments. Surface treatment of fiber post with TiF4 4 wt/v% could be used to improve the bond strength with calcium silicate-based cements.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Compostos de Cálcio , Análise do Estresse Dentário , Humanos , Teste de Materiais , Cimentos de Resina , Silicatos
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