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1.
J Adhes Dent ; 22(5): 483-501, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33073780

RESUMO

PURPOSE: Universal adhesives (UAs) are applied in 2-step etch-and-rinse (2-E&R) or 1-step self-etch (1-SE) mode. This study investigated whether three UAs could benefit from a highly filled extra bonding layer (EBL), turning them into 3-E&R and 2-SE UAs, respectively, thus also compensating for the commonly thin film thickness of UAs. MATERIALS AND METHODS: Microtensile bond strength (µTBS) to bur-cut dentin of Clearfil Universal Bond Quick (C-UBq, Kuraray Noritake), G-Premio Bond (G-PrB, GC) and Prime&Bond Active (P&Ba, Dentsply Sirona), applied in E&R and SE mode without/with the adhesive resin (EBL) of OptiBond FL (Opti-FL_ar, Kerr), was compared to that of the 3-E&Ra OptiBond FL (Opti-FL; Kerr), which was also employed in 2-SE mode. As a cross reference, the SE primer of Clearfil SE Bond 2 (Kuraray Noritake) was combined with Opti-FL_ar (C-SE2/Opti-FL) and again applied in 2-SE and 3-E&R mode. µTBS was measured after 1 month of water storage (37°C) and additional 25,000 and 50,000 thermocycles (TC). All µTBS were statistically analyzed using three different linear mixed-effects models with specific contrasts (p < 0.05). RESULTS: Overall, the four parameters (adhesive, bonding mode, aging, EBL) significantly influenced µTBS. G-PrB and P&Ba benefited from EBL when applied in both E&R and SE bonding modes. In E&R mode, P&Ba generally revealed the highest µTBS; C-UBq presented an intermediate and G-PrB the lowest µTBS. No significant differences were found between different bonding modes. C-SE2/Opti-FL outperformed Opti-FL in 3-E&R and 2-SE_1 month/25k. CONCLUSION: The overall benefit of EBL on the 1-month and TC-aged bonding efficacy differed for the different UAs tested.


Assuntos
Colagem Dentária , Adesivos Dentinários , Cimentos Dentários , Dentina , Teste de Materiais , Resistência à Tração
2.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(5): 931-937, 2020 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-33047732

RESUMO

OBJECTIVE: To study the effect of bioactive glass (BG) on the dentin bond strength and the microleakage of hybrid layer. METHODS: In the study, 30 dentin planes were prepared from the third molars with no caries and equally assigned to the control group, BG group, and sodium trimetaphosphate (STMP)-polyacrylic acid (PAA)-BG group (S-P-BG group), randomly. After etched with 35% phosphoric acid, the dentin planes of BG group were pretreated with 0.5 g/L BG, and the dentin planes of S-P-BG group were pretreated with 5% STMP, 5% PAA and 0.5 g/L BG. No additional pretreatment was done to the dentin planes of control group. Then the dentin planes were bonded using 3M Single Bond 2 adhesive to 3M Z350XT composite resin, and cut into 0.9 mm×0.9 mm column samples, which were stored at 37 ℃ artificial saliva (AS). After 24 hours, 1 month, and 3 months, the microtensile bond strength test was performed. The data were analyzed using one-way ANOVA and LSD method. The morphology of the bond fracture interface was observed with scanning electron microscope. Other 27 teeth were collected and the enamel layer and roots cut off, with the pulp chamber exposed. 0.1% rhodamine B was added to the 3M Single Bond 2 adhesive, and then the adhesive was applied to complete the bonding procedures as above. The teeth were stored in 37 ℃ AS for 24 hours, 1 month, 3 months, and then 0.1% sodium fluorescein solution was placed in the chambers and stained for 1 hour. Confocal laser scanning microscopy was used to observe the interface morphology and microleakage of the hybrid layer. RESULTS: At the end of 24 hours and 1 month, there was no significant difference in the microtensile bond strength among the three groups (P>0.05). After 3 months of soaking, the S-P-BG group [(36.91±7.07) MPa] had significantly higher microtensile bond strength than the control group [(32.73±8.06) MPa] (P=0.026); For the control group and the BG group, the microtensile bond strength significantly decreased at the end of 3 months compared with 24 hours (control group: P=0.017, BG group: P=0.01); The microtensile bond strength of S-P-BG group af the end of 3 months had no significant difference in compared with 24 hours [(37.99±7.98) MPa] (P>0.05). Observation of the fracture surface at the 24 hours showed no obvious mineralization in all the three groups. After 1 and 3 months, mineral formation was observed in BG group and S-P-BG group, and no obvious collagen exposure was observed in S-P-BG group. Confocal laser scanning microscopy revealed no obvious differences in the morphology and quantity of the resin tag in the control group, BG group and S-P-BG group. At the end of 24 hours, leakage was found in all the three groups. The microleakage of the control group increased at the end of 3 months, while the microleakage of the BG and S-P-BG groups decreased. CONCLUSION: BG pretreatment of dentin bonding interface can induce mineralization at the bonding interface and reduce the microleakage of the hybrid layer; pretreating the dentin bonding interface with STMP, PAA and BG may enhance the maintaining of the dentin bonding durability.


Assuntos
Adesivos Dentinários , Cimentos de Resina , Dentina , Vidro , Resistência à Tração
3.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(4): 438-442, 2020 Aug 01.
Artigo em Chinês | MEDLINE | ID: mdl-32865365

RESUMO

Noncarious cervical sclerotic lesions (NCSL) are dental cervical lesions with noncarious sclerotic dentine (NCSD), which appears smooth, hard, and either light yellow or dark brown. Most NCSLs are wedge or dish shaped and commonly occur in canines and premolars, leading to dental hypersensitivity and aesthetic defect. The principal treatment is composite resin restoration; however, many clinical problems, such as retention loss, should not be ignored. NCSL's bonding interface includes NCSD and enamel, and interface pre-treatment can promote the bonding effect. This review summarizes current surface treatment methods and their influence on the bonding effectiveness of NCSL to provide guidance for clinical practice.


Assuntos
Colagem Dentária , Adesivos Dentinários , Condicionamento Ácido do Dente , Resinas Compostas , Restauração Dentária Permanente , Colo do Dente
4.
Acta Odontol Latinoam ; 33(2): 135-142, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920616

RESUMO

This study evaluated the influence of the mode and time of solvent evaporation on the tensile strength (TS), flexural strength (FS) and elastic modulus (EM) of two adhesive systems: Scotchbond Multipurpose (SBMP) and Clearfil SE (CSEB). For this purpose, rectangular samples (2x1x7 mm) were prepared with 10 µL of primer and the solvents were evaporated with air spray at (23±1) ºC, (40±1) ºC and negative control (without spray). For each temperature, the times of 5, 20, 30, and 60 seconds were investigated. The statistical results showed that evaporation at 40±1ºC resulted in better EM for the two adhesives tested and all the evaporation times evaluated. However, there were no significant differences between the times and modes of evaporation for TS. The results of this study indicate that evaporation at a temperature of (40±1) °C could improve the elastic modulus of both adhesives tested, regardless of the evaporating time.


Assuntos
Adesivos/química , Cimentos Dentários/química , Adesivos Dentinários/química , Solventes/farmacologia , Resistência à Tração , Dessecação , Humanos , Teste de Materiais , Volatilização
5.
Braz Oral Res ; 34: e105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32876118

RESUMO

The aim of this research was to evaluate the influence of MDP (10-methacryloyloxydecyl dihydrogen phosphate) concentration and application mode of experimental adhesives on microshear bond strength (µSBS) to dentin after storage in distilled water at 37°C for 24h and 6 months. Five experimental adhesives were prepared with: CQ, DABE, BHT, ethanol, HEMA, TEGDMA, Bis-EMA, UDMA, and Bis-GMA. Concentrations of 0 wt%, 3 wt%, 9 wt%, 12 wt% or 15 wt% of MDP were added to their composition. The adhesives were applied to flat dentin surfaces in etch-and-rinse or self-etching modes. Cylindrical molds filled with light-cured composite resin were placed above the dentin. The specimens were stored in distilled water at 37oC for 24h or 6 months and submitted to µSBS testing. The adhesives were also submitted to pH analysis. The data were analyzed by one-way ANOVA, three-way ANOVA and Tukey's test (α = 5%). All the adhesives used in the etch-and-rinse mode showed significantly higher bond strength than the adhesives applied in the self-etching approach. The 9 wt% adhesive showed the highest bond strength values, and 3 wt% was most stable after storage. A strong negative correlation between MDP concentration and pH was observed. It was concluded that the formulations with low concentrations of MDP (up to 9 wt%) showed better results for bond strength and bond strength degradation over time.


Assuntos
Colagem Dentária , Adesividade , Resinas Compostas , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência à Tração
6.
Ned Tijdschr Tandheelkd ; 127(7-08): 417-423, 2020.
Artigo em Holandês | MEDLINE | ID: mdl-32840497

RESUMO

This in vitro study investigated whether aging of restorative materials influences secondary caries development. The research question was whether antibacterial bonding maintained its effectiveness after aging. 60 enamel-dentine blocks were restored using 3 different restorative materials (n = 20 per material): composite with conventional bonding, composite with antibacterial bonding and amalgam. Half of the samples in each group (n = 10) were artificially aged through exposure to a sucrose biofilm model. Lesion depth was subsequently measured using transversal microradiography. Aging led to deeper lesions in the composite with antibacterial bonding group (CAB), compared to fresh samples. These fresh samples showed lesions less deep than fresh samples of composite with conventional bonding. After aging, this effect was absent. Within the limitations of this short-term in vitro study, it can be concluded that aging of restorative materials can influence caries progression. Antibacterial bonding materials lose their effectiveness over time.


Assuntos
Cárie Dentária , Adesivos Dentinários , Envelhecimento , Antibacterianos , Resinas Compostas , Restauração Dentária Permanente , Dentina , Humanos
7.
J Esthet Restor Dent ; 32(7): 691-698, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757232

RESUMO

OBJECTIVES: To compare the clinical performance of a universal adhesive in class V non-carious cervical lesions (NCCLs) using two surface treatment protocols (self-etch [SfE] vs selective-enamel-etch [SelE]). MATERIAL AND METHODS: Thirty-three adults, each with ≥2 NCCLs, received one resin composite restoration utilizing a SfE universal adhesive and another utilizing the adhesive and SelE with 37% phosphoric acid. Restorations were evaluated for sensitivity, retention, marginal discoloration, marginal adaptation, and clinical acceptability through 24 months using Cochran-Mantel-Haenszel tests for stratified, ordered categorical outcomes. RESULTS: Sixty-six restorations (35 SfE, 31 SelE; 27 volunteers) were evaluated at 24 months. There were no significant differences between SfE and SelE for sensitivity, retention, marginal adaptation, or clinical acceptability. One SfE restoration was lost. Marginal adaptation was significantly worse at 24 months than baseline for SelE (P = 0.01), but not for SfE. Marginal discoloration was significantly worse for SfE (P = 0.02), but not for SelE. Sensitivity improved from baseline to 24 months for both groups (SelE P = 0.004, SfE P = 0.002). CONCLUSIONS: Twenty-four-month data indicated significantly reduced sensitivity for both groups, worse marginal discoloration for SfE, and worse marginal adaptation for SelE. No changes in retention or clinical acceptability were observed in either group. All retained restorations were clinically acceptable at 24 months. CLINICAL SIGNIFICANCE: Both self-etch and selective enamel etch techniques with a universal adhesive produced clinically acceptable results in resin composite restorations for NCCLs over 2 years.


Assuntos
Restauração Dentária Permanente , Colo do Dente , Adulto , Resinas Compostas , Cimentos Dentários , Adaptação Marginal Dentária , Adesivos Dentinários , Humanos , Cimentos de Resina
8.
J Dent Child (Chic) ; 87(2): 69-76, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32787999

RESUMO

Purpose: To evaluate the morphological alterations in enamel and dentin of primary teeth following radiotherapy (RT) and to determine the best adhesive technique and time to carry out restorative procedures.
Methods: Enamel and dentin fragments of primary teeth were randomly assigned into four groups (n=30): G1 (control)-non-irradiated, only restorative procedure; G2- restorative procedure immediately before RT; G3-restorative procedure 24 hours after RT; and G4-restorative procedure six months after RT. Each group was divided into one of two subgroups according to the adhesive system used for restoration: (1) AdperSingle Bond 2 (SB); and (2) ClearfillSE Bond (CL). The specimens were submitted to fractionated RT until they reached the final dose of 60 Gy. They were then subjected to confocal microscopy and the shear bond strength test. Data were analyzed using two-way analysis of variance followed by Tukey's tests ( α = five percent).
Results: Morphological changes were first observed in enamel and dentin after 40 Gy of irradiation. G4 bond strength values were similar to G1 in the CL and SB groups for enamel and in the CL group for dentin (P >0.05). G2 showed the lowest values for enamel and dentin (P <0.05). In G3, CL presented the highest strength values in enamel; for G4, the highest values were found in dentin (P <0.05).
Conclusions: Radiotherapy affected the morphological surface of enamel and dentin. The restorations placed immediately after RT had the weakest shear bond strength, and the restorations placed six months after RT had similar means of bond strength compared to the nonirradiated teeth in enamel, regardless of the adhesive system used. In dentin, CL showed better performance than SB.


Assuntos
Colagem Dentária , Adesivos Dentinários , Resinas Compostas , Cimentos Dentários , Dentina , Humanos , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento , Dente Decíduo
9.
Am J Dent ; 33(4): 206-212, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32794396

RESUMO

PURPOSE: This double-blind, randomized clinical trial evaluated the influence of dentin moisture on postoperative sensitivity (POS) in posterior restorations using a simplified etch-and-rinse adhesive, until 12 months of clinical service. METHODS: 90 restorations were inserted in 45 patients to treat carious lesions or to replace existing posterior restorations with a depth ≥ 3 mm. After cavity preparation, the simplified etch-and-rinse adhesive (Adper Single Bond 2) was applied on dry or wet dentin followed by a bulk-fill resin composite (Filtek Bulk Fill) under rubber dam isolation. The patient's spontaneous and stimulated POS was evaluated at baseline and after 7 days, 6 months, and 12 months of clinical evaluation. The secondary parameters (marginal discoloration, marginal adaptation, fracture and recurrence of caries) were evaluated by World Dental Federation (FDI) criteria after 7 days, 6 and 12 months of clinical evaluation. RESULTS: No significant spontaneous and stimulated POS was observed when dry and wet dentin were compared (P> 0.05). A significant and higher risk of spontaneous POS (18.6%; 95% CI 9.7 to 32.6) occurred up to 48 hours after restoration placement for both groups when compared to all evaluation times (P< 0.03). However, the intensity of POS was mild at up to 48 hours with a difference between the dry and wet dentin groups (P> 0.79). When secondary parameters were evaluated, no significant difference between the groups were observed (P> 0.05). CLINICAL SIGNIFICANCE: The moisture level of the dentin substrate in posterior restorations does not influence POS in bulk-fill resin composite posterior restorations when associated with an etch-and-rinse ethanol-based adhesive system.


Assuntos
Cárie Dentária , Sensibilidade da Dentina , Resinas Compostas , Adaptação Marginal Dentária , Restauração Dentária Permanente , Dentina , Adesivos Dentinários , Método Duplo-Cego , Humanos , Cimentos de Resina
10.
Braz Dent J ; 31(3): 272-280, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32667522

RESUMO

The purpose of this study was to evaluate the influence of the application mode of three universal adhesive systems on interfacial physical properties of indirect composite restorations adhesively cemented to dentin cavities. Seventy-eight bovine lower incisors were selected and a slice of dentin (thickness: 2 mm) between the buccal surface and pulp chamber was obtained for each tooth. Conical cavities were made on this surface. The internal walls of the cavities were then coated with a hydrophilic gel, filled with composite resin and photopolymerized. The dentin/cone sets were divided into 6 groups (n=10) according to type of universal adhesive (TETRI: Tetric N Bond, FUT: Futura Bond U, SBU: Single Bond Universal) and acid etching on dentin (A: with acid etching; WA: without acid etching). The acid etching and the adhesive systems were applied to the surface of the dentin. All composite resin cones were sandblasted (Al2O3, 20 s) and silanized. After surface treatment, the cones were cemented (RelyX Ultimate) into the dentin cavity and photopolymerized. After thermocycling (10,000 cycles), samples were submitted to marginal adaptation analysis (using caries detector dye), push-out test (0.5 mm/min), and failure mode analysis. Additional samples were prepared for nanoleakage analysis (SEM). The data (MPa) were analyzed by two-way ANOVA and Tukey's post-test (5%). The groups in which the dentin was acid etched showed significantly lower bond strength values in the push-out test (p<0.01). Dentin acid etching significantly reduced the bond strength between universal adhesive systems and dentin in indirect restorative procedures.


Assuntos
Colagem Dentária , Adesivos Dentinários , Animais , Bovinos , Resinas Compostas , Cimentos Dentários , Cavidade Pulpar , Dentina , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície , Resistência à Tração
11.
Dent Mater J ; 39(4): 534-538, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32624553

RESUMO

Self-etch adhesive (SEA) systems simplify bonding procedures. It is believed that good mechanical retention and chemical bonding are both important factors to obtain reliable bonding to enamel. The enamel acid-base resistant zone (ABRZ) has been confirmed at the adhesive/enamel interface by scanning electron microscopic observation. However, the formation of enamel ABRZ is influenced by the type and components of adhesive systems. Chemical interactions by a functional monomer with hydroxyapatite strongly support the explanation of the mechanism for enamel ABRZ formation. The ABRZ created by MDP-containing SEA systems has shown good potential to resist acid attack from simulated recurrent caries models. In addition, fluoride release may enhance acid resistance. It has been proposed that such a reinforced enamel be termed "Super Enamel". The concept of the formation of super enamel may contribute to protecting enamel, and conserve tooth structure leading to improved restoration longevity.


Assuntos
Condicionamento Ácido do Dente , Colagem Dentária , Cimentos Dentários , Esmalte Dentário , Dentina , Adesivos Dentinários , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Propriedades de Superfície
12.
Braz Oral Res ; 34: e081, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32696905

RESUMO

The aim of this study was to investigate the influence of shortening of etching time for dentin on the restoration survival after selective carious tissue removal in primary molars. This two-arm randomized clinical trial included sixty-two subjects (5-8 year-old) and 100 primary molars presenting moderate dentin carious lesions on occlusal surface. The sample was randomly assigned into groups previously to adhesive application (Adper Single Bond 2; 3M ESPE): etching time recommended by manufacturer (15 s) or reduced (7 s). Resin composite (Filtek Bulk Fill Posterior Restorative; 3M ESPE) was inserted in a single increment for all restorations. Restorations were evaluated at 1, 6, 12, and 18 months using FDI criteria. Survival estimates for restorations' longevity were evaluated with Kaplan-Meier method. Multivariate Cox regression analysis with shared frailty was used to assess the factors associated with failures (p < 0.05). The etching time did not influence the restorations' survival (HR 0.35 95%CI 0.11-1.12; p = 0.06). Mean estimated time of survival was 17.6 months (95%CI, 17.2-17.9). The survival rates at the 18-month follow-up were 75.7% and 91.4% (AFR: 16.9% and 5.7%) when primary dentin was acid etched for 15 and 7 s, respectively (log-rank p = 0.06). In conclusion, the etching time for dentin did not influence the clinical behavior of adhesives restorations. However, there was a tendency for better clinical outcome when using etching time of 7 s.


Assuntos
Dente Decíduo , Resinas Compostas , Restauração Dentária Permanente , Dentina , Adesivos Dentinários , Dente Molar
13.
J Adhes Dent ; 22(4): 393-398, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32666065

RESUMO

PURPOSE: To assess the effect of the application of different electric currents on dentin bonding and resin infiltration of self-etching and etch-and-rinse adhesives. MATERIALS AND METHODS: Two hundred four sound third molars were selected and divided in groups according to the adhesive (self-etch [CSE, Clearfil SE Bond, Kuraray Noritake], universal [SBU, Single Bond Universal, 3M Oral Care], and etch-and-rinse [SB2, Adper Single Bond 2 (SB2), 3M Oral Care]) and electrical current used (0, 5, 10, 15, 20, 25, 30, and 35 µA). Light curing was performed for 10 s with an LED-curing unit at 1000 mW/cm2. Composite blocks were constructed of nanofilled composite in increments of 2 mm, which were light cured for 20 s. Specimens were sectioned into sticks with a cross-sectional area of ~1 mm2 and stored in distilled water at 37°C for 24 h. Microtensile bond strength (µTBS) testing (n = 8) was performed using a universal testing machine at a crosshead speed of 0.5 mm/min until failure. The bonding quality (n = 2) of adhesives applied with or without 35-µA electric current was evaluated using confocal laser scanning microscopy. Bond strengths were analyzed with two-way ANOVA and Tukey's test (α = 0.05). RESULTS: CSE presented the highest µTBS for all electrical currents tested. For CSE and SBU, electrical currents from 0-20 µA showed the lowest µTBS. Electrical currents from 0-10 and 20-25 µA yielded the lowest µTBS for SB2. CSE and SB2 applied under 35 µA showed a greater number of resin tags in dentin tubules. Fluorescein penetration into the hybrid layer was found for SBU applied without electric current. CONCLUSION: The application of adhesives using 35-µA electric current improved the bond strength and quality of the adhesive interface.


Assuntos
Colagem Dentária , Adesivos Dentinários , Adesivos , Resinas Compostas , Dentina , Teste de Materiais , Cimentos de Resina , Resistência à Tração
14.
J Adhes Dent ; 22(4): 399-407, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32666066

RESUMO

PURPOSE: The aim of this study was to evaluate the chemomechanical properties, antibacterial activity, and cytotoxicity of an experimental adhesive resin containing halloysite nanotubes (HNT), doped with alkyl trimethyl ammonium bromide (ATAB). MATERIALS AND METHODS: A filler of HNT doped with ATAB was obtained (ATAB:HNT) and incorporated (5 wt%) into a resin blend made of bisphenol A glycerolate dimethacrylate, 2-hydroxyethyl methacrylate and a photoinitiator/co-initiator system (GATAB:HNT). The same resin blend without ATAB:HNT was used as control (Ctrl). The ATAB:HNT filler was assessed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The two tested adhesives were evaluated for degree of conversion (DC) in vitro and in situ, softening in alcohol, dentin microtensile bond strength (µTBS), antibacterial activity, and cytotoxicity (n = 5). RESULTS: SEM showed that the nanotubes had a characteristic tubular-needle morphology, while the TEM analysis confirmed the presence of ATAB inside the lumens of HNT. The incorporation of ATAB:HNT induced no reduction (p > 0.05) of the DC either in situ or in vitro. No difference was encountered after the softening challenge test (p > 0.05) and no difference was found in µTBS between the two adhesives, both at 24 h (p > 0.05) and after 6 months of storage in distilled water (p > 0.05). However, ATAB:HNT reduced Streptococcus mutans viability (p < 0.05) without a cytotoxic effect on pulp cells (p > 0.05). CONCLUSIONS: GATAB:HNT adhesive demonstrated appropriate polymerization without significant differences in softening after solvent immersion, while concomitantly maintaining reliable bond strength after 6 months of water aging. Moreover, the ATAB:HNT filler can provide antibacterial activity to the adhesive resin without affecting pulp cell viability.


Assuntos
Colagem Dentária , Nanotubos , Brometos , Argila , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Microscopia Eletrônica de Varredura , Compostos de Amônio Quaternário , Cimentos de Resina , Resistência à Tração
15.
J Adhes Dent ; 22(4): 415-420, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32666068

RESUMO

PURPOSE: To investigate whether interfacial enzymatic activity and adhesion receptiveness of artificial caries-affected dentin (ACAD) simulate those of natural caries-affected dentin (NCAD). MATERIALS AND METHODS: Thirty dentin specimens were prepared from human molars to determine interfacial gelatinolytic activity using in situ zymography and adhesion experiments (micropermeability and bond strength [µTBS]). Groups were formed according to the type of dentin: artificial caries-affected dentin (ACAD), natural caries-affected dentin (NCAD), or sound dentin. ACAD was produced by incubating dentin with Streptococcus mutans in a chemically defined medium (CDM) with 1% sucrose for 7 days at 37°C under anaerobic conditions. CDM was replaced daily, and the sterility as well as the pH of the culture was monitored. Adhesion experiments employed Single Bond Universal (3M Oral Care) in self-etch mode. Data were individually processed and analyzed using ANOVA and post-hoc tests (α = 0.05). RESULTS: The enzymatic activity of ACAD was similar to that of sound dentin, but was lower than that of NCAD, which elicited the highest activity (p < 0.05). Interfacial micropermeability intensity at the hybrid layer or in underlying dentin (5 µm below the interface) was similar in all types of dentin (p > 0.05). On the other hand, substrate permeability was higher for NCAD than for ACAD. The highest sealing ability was detected in sound dentin. Bond strengths to ACAD were higher than to NCAD. However, the highest µTBS was observed in sound dentin (p < 0.05). CONCLUSION: Artificial caries-affected dentin simulated neither the gelatinolytic activity nor bonding receptiveness of natural caries-affected dentin.


Assuntos
Colagem Dentária , Cárie Dentária , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à Tração
16.
J Prosthet Dent ; 124(4): 487.e1-487.e7, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32682525

RESUMO

STATEMENT OF PROBLEM: The limited durability of resin-dentin bonds is considered a major disadvantage of adhesive restorations. Therefore, clinical strategies have been developed to improve hybrid layer stability over time. These strategies require testing. PURPOSE: The purpose of this in vitro study was to evaluate the influence of preheating and the inclusion of a bioactive glass in a unidose 3-step etch-and-rinse adhesive system on the adhesion of direct composite resin restorations. MATERIAL AND METHODS: Dentin disks from 80 molars were assigned to 8 groups (n=10): CG-T1/CG-T2: control group; PG-T1/PG-T2: adhesive preheated to 68 °C; BG-T1/BG-T2: 0.05 mg of Bioglass 45S5 (BAG) (particle size: 3 µm) added to primer; PBG-T1/PBG-T2: adhesive and BAG-modified primer preheated to 68 °C. Sticks were fabricated for microtensile bond strength (µTBS) testing and were tested at 1 week (T1) and after 6 months (T2) of storage. µTBS data were analyzed by using 2-way ANOVA and the Tukey-Kramer post hoc test (α=.05). Scanning electron microscopy was used to analyze the failure mode. Attenuated total reflection Fourier transform infrared spectroscopy was used to quantitatively analyze the modifications to the chemical structure of the adhesive system from preheating and BAG inclusion. RESULTS: The mean bond strength values at 1 week were statistically different, with PG-T1 (69.8 ±7.8 MPa) superior to all other groups. CG-T1 (58.2 ±6.7 MPa), BG-T1 (60.7 ±4.4 MPa), and PBG-T1 (61.0 ±4.6 MPa) were not statistically different (P>.05). PG-T2 maintained the highest bond strength at 6 months (68.3 ±3.7 MPa), with no decrease in µTBS observed over time. Failure modes were mostly adhesive. Attenuated total reflection Fourier transform infrared spectroscopy analysis reported that primer preheating caused solvent evaporation and revealed that preheating the bonding agent promoted the condensation reaction between the silane and adhesive fillers. CONCLUSIONS: No decrease in µTBS was observed for any group after 6 months. Preheating the adhesive system (primer and bonding resin) significantly increased the 1-week and 6-month µTBS. Inclusion of BAG did not affect the bond strength.


Assuntos
Colagem Dentária , Adesivos Dentinários , Resinas Compostas , Dentina , Teste de Materiais , Cimentos de Resina , Resistência à Tração
17.
J Appl Oral Sci ; 28: e20190737, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32609185

RESUMO

OBJECTIVE: Laboratory tests are routinely used to test bonding properties of dental adhesives. Various aging methods that simulate the oral environment are used to complement these tests for assessment of adhesive bond durability. However, most of these methods challenge hydrolytic and mechanical stability of the adhesive- enamel/dentin interface, and not the biostability of dental adhesives. To compare resin-dentin microtensile bond strength (µTBS) after a 15-day Streptococcus mutans (SM) or Streptococcus sobrinus (SS) bacterial exposure to the 6-month water storage (WS) ISO 11405 type 3 test. METHODOLOGY: A total of 31 molars were flattened and their exposed dentin was restored with Optibond-FL adhesive system and Z-100 dental composite. Each restored molar was sectioned and trimmed into four dumbbell-shaped specimens, and randomly distributed based on the following aging conditions: A) 6 months of WS (n=31), B) 5.5 months of WS + 15 days of a SM-biofilm challenge (n=31), C) 15 days of a SM-biofilm challenge (n=31) and D) 15 days of a SS-biofilm challenge (n=31). µTBS were determined and the failure modes were classified using light microscopy. RESULTS: Statistical analyses showed that each type of aging condition affected µTBS (p<0.0001). For Group A (49.7±15.5MPa), the mean µTBS was significantly greater than in Groups B (19.3±6.3MPa), C (19.9±5.9MPa) and D (23.6±7.9MPa). For Group D, the mean µTBS was also significantly greater than for Groups B and C, but no difference was observed between Groups B and C. CONCLUSION: A Streptococcus mutans- or Streptococcus sobrinus-based biofilm challenge for 15 days resulted in a significantly lower µTBS than did the ISO 11405 recommended 6 months of water storage. This type of biofilm-based aging model seems to be a practical method for testing biostability of resin-dentin bonding.


Assuntos
Colagem Dentária , Adesivos Dentinários , Biofilmes , Resinas Compostas , Cimentos Dentários , Dentina , Teste de Materiais , Cimentos de Resina , Resistência à Tração
18.
Shanghai Kou Qiang Yi Xue ; 29(2): 150-154, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32626877

RESUMO

PURPOSE: To evaluate the effect of 2% chlorhexidine(CHX) on the self-etching adhesive to dentin. METHODS: Fifty carious free molars were selected to expose the flat dentin surface. The specimens were bonded with composite resin by self-etching adhesive ,which were pretreated by 2% CHX for 0, 15, 30, 45 and 60 s. The microtensile bond strength (µTBS) and scanning electron microscope(SEM) were evaluated before and after thermocycling. SPSS 19.0 software package was used for statistical analysis. RESULTS: µTBS of the 45 and 60s-CHX pretreated group had significant difference before thermocycling, significantly higher than the control group(P<0.05). The 60s-CHX pretreated group showed significant greater µTBS than the control group after thermocycling(P<0.05). CONCLUSIONS: 2%CHX pretreatment can improve the bonding strength of the self-etching adhesive, and slow down the aging progress of bonding interface.


Assuntos
Clorexidina , Colagem Dentária , Resinas Compostas , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Estresse Mecânico , Resistência à Tração
19.
J Indian Soc Pedod Prev Dent ; 38(2): 138-144, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32611859

RESUMO

Background: Use of silver diamine fluoride (SDF) after selective caries excavation can arrest the further progress of the carious lesion. Application of potassium iodide (KI) can reduce the staining due to SDF. Aim: The aim of the study was to evaluate the effect of the application of SDF, with and without acid etching and KI on the bond strength of resin-modified glass ionomer cement (RMGIC) to the carious dentin of primary teeth. Materials and Methods: In thisin vitro study, caries was induced on the occlusal surface by inoculating Streptococcus mutans strain in 36 extracted primary molars. The teeth were divided into four groups (n = 9), and the following treatments were done to the carious dentin prior to final restoration with RMGIC: Group I: 10% polyacrylic acid conditioner, Group II: 38% SDF, Group III: 37% phosphoric acid etchant followed by 38% SDF, and Group IV: 37% phosphoric acid etchant followed by 38% SDF and 10% potassium iodide solution. The microtensile bond strength was measured using universal testing machine. Failure modes were recorded using a scanning electron microscope. Results: There was no significant difference in microtensile bond strengths between the groups (P = 0.665), with the highest value seen in Group III. Conclusions: Application of SDF with or without acid etching and KI does not affect the bond strength of RMGIC to carious dentin of primary teeth.


Assuntos
Colagem Dentária , Cárie Dentária , Dentina , Adesivos Dentinários , Fluoretos Tópicos , Cimentos de Ionômeros de Vidro , Humanos , Teste de Materiais , Compostos de Amônio Quaternário , Cimentos de Resina , Compostos de Prata , Resistência à Tração , Dente Decíduo
20.
Braz Dent J ; 31(2): 179-185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32556018

RESUMO

The aim was to evaluate, in vitro, the influence of pH cycling on microtensile bond strength (µTBS) and percentage of nanoleakage (%NL) in the dentin-adhesive interface. Flat dentin surfaces were obtained in 56 extracted third molars. The teeth were randomly divided into four groups (n=14): G1- Single Bond Universal (etch-and-rinse mode); G2- Single Bond Universal (self-etch mode); G3- Scotchbond Multi-Purpose; G4- Clearfil SE Bond. A block of composite was built on the adhesive area. Eight tooth/resin sets were cut parallel to the tooth's long axis to obtain 48 beams (0.8 mm2) for each group. Half of the beams were submitted to four cycles of pH cycling (demineralizing solution for 6 h and remineralizing solution for 18 h). The samples were submitted to µTBS test in a universal testing machine. Six tooth/resin sets were cut parallel to the tooth's long axis to obtain three slices of the central region (1.0 mm thickness). Half of the slices were submitted to pH cycling. The nanoleakage methodology was applied to obtain the %NL at the adhesive interfaces. According to two-way ANOVA, the interaction between factors (adhesive system x storage) was significant (p=0.0001) for µTBS and %NL. After pH cycling, there was a significant decrease in µTBS and a significant increase in %NL for all adhesives. The adhesives applied in the self-etch mode obtained lower %NL, differing significantly from the etch-and-rinse adhesives. It was concluded that the pH cycling negatively influenced the µTBS and %NL for all adhesives evaluated. However, self-etch adhesives allowed less %NL.


Assuntos
Colagem Dentária , Adesivos Dentinários , Cimentos Dentários , Dentina , Teste de Materiais , Cimentos de Resina , Resistência à Tração
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