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1.
J Adhes Dent ; 23(4): 357-365, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34269546

RESUMO

PURPOSE: This study evaluated whether active application of self-etching adhesives would influence their microtensile bond strength (µTBS) to dentin cut with burs of different grit sizes. MATERIALS AND METHODS: Eighty-four human premolars were divided into 12 groups according to 1) two dentin surface preparations with either superfine- or regular-grit diamond burs; 2) three adhesives - Clearfil SE Bond 2 (SE2), Scotchbond Universal (SBU, 3M Oral Care) and G-Premio Bond (GPB, GC); and 3) two application modes of each adhesive (active or passive). Six bonded teeth per group were sectioned into sticks for µTBS testing. Statistical analyses were performed using 3-way ANOVA followed by Duncan's test (p < 0.05). Additional teeth were prepared to observe the interaction between the dentin smear layer obtained from each bur with adhesives under different application modes using transmission electron microscopy (TEM). RESULTS: Active application significantly increased the dentin bond strength of SE2, irrespective of the kind of bur used (p < 0.05). The highest bond strength of SBU was observed when bonded to superfine-grit diamond bur-cut dentin with the active application. There was, however, no influence of the tested factors on GPB group (p > 0.05). TEM observation showed that active application promoted dentin smear layer dissolution in all adhesive groups. CONCLUSIONS: Bond strengths of self-etching adhesives to dentin are influenced by bur-cut smear layers and mainly by application mode of adhesive materials. Active application improves µTBS of self-etching adhesives by enhancing smear layer modification and resin penetration into bur-cut dentin.


Assuntos
Colagem Dentária , Adesivos Dentinários , Adesivos , Resinas Compostas , Cimentos Dentários , Dentina , Humanos , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície , Resistência à Tração
2.
Polymers (Basel) ; 13(7)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33805907

RESUMO

This study evaluated an experimental two-step self-etch adhesive (BZF-29, BZF) by comparing it with a reference two-step self-etch adhesive (Clearfil Megabond 2, MB) and a universal adhesive (G-Premio Bond, GP) for microtensile bond strength (µTBS) and resin-dentin interfacial characteristics. Twenty-four human third molars were used for the µTBS test. Bonded peripheral dentin slices were separated to observe the resin-dentin interface and measure the adhesive layer thickness with SEM. µTBS data of the central beams were obtained after 24 h and 6 months of water storage. Fracture modes were determined using a stereomicroscope and SEM. Nine additional third molars were used to determine the elastic modulus (E) employing an ultra microhardness tester. Water storage did not affect µTBS of the tested adhesives (p > 0.05). µTBS of BZF and MB were similar but significantly higher than GP (p < 0.05). BZF achieved the highest adhesive layer thickness, while GP the lowest. E of BZF and MB were comparable but significantly lower than GP (p < 0.05). Except for GP, the predominant fracture mode was nonadhesive. The superior bonding performance of BZF and MB could be attributed to their better mechanical property and increased adhesive thickness imparting better stress relief at the interface.

3.
J Adhes Dent ; 22(3): 311-320, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32435771

RESUMO

PURPOSE: To evaluate the effects of double application of resin cement primers to dentin prepared with different diamond burs on the cement-dentin bond strengths. MATERIALS AND METHODS: Sixty flat dentin surfaces were prepared and divided into 12 groups (n = 5) according to three experimental factors: 1. resin cements: RelyX Ultimate (RU), Multilink Automix (ML), and Panavia V5 (PV); 2. resin cement primer application: single or double; 3. dentin surface preparation with regular or superfine diamond burs. Cement-dentin sticks (1 mm2) were prepared for and underwent microtensile bond strength testing (µTBS). Statistical analysis was performed using three-way ANOVA and Duncan's test (α = 0.05). Fractured surfaces and cement-dentin interfaces were observed using SEM. Additional teeth were used to observe the demineralization effect of resin cement primers with SEM and transmission electron microscopy (TEM). RESULTS: All tested factors demonstrated significant effects on µTBS (p < 0.001). The combination of PV with superfine-grit bur and double application yielded the highest bond strengths. Surfaces prepared with superfine-grit burs demonstrated higher µTBS than did the regular-grit group, but a significant effect was not observed for all groups. The double application of primer significantly increased the bond strength for most combinations, except for PV with superfine-grit bur-prepared dentin. CONCLUSIONS: PV showed higher bond strengths than other resin cements. Double application of primer improved the bond strength of all cements to dentin. Bond strengths were higher when dentin was prepared with a superfine-grit bur.


Assuntos
Colagem Dentária , Cimentos de Resina , Dentina , Adesivos Dentinários , Diamante , Teste de Materiais , Propriedades de Superfície , Resistência à Tração
4.
Eur J Oral Sci ; 128(3): 246-254, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32396258

RESUMO

Using transmission electron microscopy (TEM), this study investigated the characteristics of smear layers after preparation of dentin surfaces using different methods. In addition, this study analyzed, using scanning electron microscopy (SEM), the interactions of smear layers with the various acidic agents used subsequently to treat the dentin surface. Mid-coronal dentin surfaces were prepared according to one of five instrumentation methods: fracture; grinding with carbide bur; grinding with regular-grit diamond bur; grinding with superfine-grit diamond bur; or grinding with 600-grit silicon carbide (SiC) abrasive paper. Then, each prepared dentin surface was further divided into control (no further treatment) or treatment with one of the following agents: phosphoric acid solution (PAS); phosphoric acid gel (PAG); Clearfil SE Bond 2 Primer (SE2); or Scotchbond Universal Adhesive (SBU). Longitudinal ultra-thin sections were made for TEM observations. Dentin discs, representing each surface preparation and treatment method described above, were created, and the morphology was examined by SEM. The TEM results revealed differences in thickness and denseness of the smear layer, according to the different methods of instrumentation used to prepare the dentin surface. The two forms of phosphoric acid completely removed the smear layer in all groups. Agglomerated silica particles were observed on the top of the collagen layer after etching with PAG. For all dentin surfaces, except for that prepared with SiC, SE2 demonstrated better etching efficacy on different smear layers, whereas SBU provided only superficial interaction.


Assuntos
Colagem Dentária , Resinas Compostas , Cimentos Dentários , Dentina , Adesivos Dentinários , Humanos , Microscopia Eletrônica de Varredura , Cimentos de Resina , Camada de Esfregaço , Propriedades de Superfície , Resistência à Tração
5.
Jpn Dent Sci Rev ; 56(1): 24-31, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31827652

RESUMO

Microtensile bond strength (µTBS) test was introduced in 1994. Since then, it has been utilized profoundly across many bond strength testing laboratories, making it currently one of the most standard and versatile bond strength test. Although it is a static and strength-based method, together with the morphological and spectroscopic investigations, it has been contributing immensely in the advancement of dentin adhesive systems. µTBS test has a greater discriminative capability than the traditional macro-shear bond test. During the early stage of its development, the authors predicted that this testing method would enable evaluation of the adhesive performances of resins to excavated carious or sclerotic dentin and the regional bond strengths of various portions of the cavity. In addition, they also stated the possibility of comparing the long-term stability of resin adhesion at various portions of the cavity walls on teeth extracted at various times after insertion of bonded restorations. In this review, we discussed the historical background, inception and the application of the µTBS test and proposed directions for further improvement of this testing method.

6.
J Nanosci Nanotechnol ; 20(5): 2668-2674, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31635601

RESUMO

In this study, we investigated water-dispersible surface modification for size- and shape-controlled fullerene nanoparticles (C60P) based on a condensation reaction with di-amino alkane. This modification provided for water dispersibility of C60P and the capability for secondary modification as well. The resultant C60P particles have several useful physical properties: water-dispersibility for ease of injection; fluorescence for detection and quantification; and a characteristic morphology to assist identification. These properties will widely extend the applications of these particles, especially into the biological fields of bioimaging and drug delivery.


Assuntos
Fulerenos , Nanopartículas , Água
7.
Dent Mater J ; 38(3): 361-367, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30814455

RESUMO

This study evaluated the effects of dehydration on the mechanical properties of adhesive resins and dentin, and on the microtensile bond strength (µTBS) of adhesives. Third molars were randomly bonded with Clearfil Mega Bond (MB) or Clearfil SE Bond 2 (SE). After water-storage (37°C; 24 h), µTBS was obtained in 'wet' (tested after 5 min of removal from storage) and 'dehydrated' (tested after 10, 15 min and 24 h) conditions by a universal tester (crosshead speed: 1 mm/min). Data were analyzed by two-way ANOVA and Duncan's test. Hardness (H), Elastic modulus (E) and weight-loss of dentin beams and adhesive-resin discs were also monitored over time and analyzed by one-way repeated measures ANOVA and Bonferroni's test (α=0.05). Significant differences in bond strength were observed for adhesives and for conditions. Except for dentin's E, dehydration caused significant gradual changes in the H, E and weight of adhesive resins and dentin (p<0.05).


Assuntos
Colagem Dentária , Adesivos Dentinários , Resinas Compostas , Desidratação , Cimentos Dentários , Dentina , Humanos , Teste de Materiais , Cimentos de Resina , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
8.
J Adhes Dent ; 21(1): 59-66, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30799472

RESUMO

PURPOSE: To evaluate the effects of double application of self-etch adhesives on their microtensile bond strength (µTBS) to dentin, as well as the hardness (H) of resin-dentin interfacial structures. MATERIALS AND METHODS: Midcoronal dentin surfaces (n = 45) were polished with 180-grit SiC paper and randomly allocated to 9 groups based on three adhesives - Scotchbond Universal Adhesive (SB), G Premio Bond (GP), and Clearfil Megabond 2 (MB) - and three application modes: single application (S), double application with light curing after each application (DL), and double application with light curing only at the end (D). Following composite-resin build up and water storage (37°C; 24 h), µTBS were obtained. The hardness of adhesive, resin-dentin interface and dentin were evaluated by nanoindentation. The µTBS and H data were analyzed by two-way ANOVA to demonstrate the effects of adhesive and application mode as well as their interaction, followed by Tukey's test (α = 0.05). Fracture modes were determined using a stereomicroscope. RESULTS: µTBS and H were significantly affected by the adhesives and their application modes (p ˂ 0.001). Double application significantly increased the µTBS and H of adhesive and resin-dentin interface (p ˂ 0.05). SB and MB showed significantly higher µTBS than GP (p ˂ 0.05). CONCLUSION: Double applications during bonding of dentin having clinically relevant smear layers were beneficial for three contemporary self-etch adhesives. The improvement in bonding performance is believed to be the result of increased chemical interaction, better solvent removal, and improved resin infiltration, leading to improved mechanical properties of the resin-dentin interface or thicker adhesive layers providing improved stress distribution.


Assuntos
Colagem Dentária , Camada de Esfregaço , Cimentos Dentários , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à Tração
9.
Clin Oral Investig ; 23(6): 2629-2635, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30327950

RESUMO

OBJECTIVES: To evaluate the effects of air-blowing time and storage time on microtensile bond strength (µTBS) of universal adhesives to dentin. MATERIALS AND METHODS: Ninety flat dentin surfaces from extracted human third molars were bonded with three universal adhesives (Clearfil Universal Bond-CU; G-Premio Bond-GP; Scotchbond Universal Adhesives-SB). Bonded dentin surfaces were air-dried for 5 s, 15 s, or 30 s followed by resin composite built-up. Resin-dentin beams were tested with µTBS test after different storage time in distilled water (24 h and 1 year). Data were analyzed by three-way ANOVA and Duncan test at (α = 0.05). Failure mode and resin-dentin interfaces were observed using a scanning electron microscope (SEM). Specific features of fractured beams after µTBS were further observed using SEM at high magnification. RESULTS: Extension of air-blowing time from 5 s to 30 s increased the 24 h µTBS of CU only. Bond strength of all adhesives significantly decreased after 1-year storage except for CU at 5 s and 30 s of air-blowing time. One-year µTBS were significantly higher when air-blowing times were extended to 15 s for SB and 30 s for CU. Air-blowing time had no influence on GP. CONCLUSION: The effect of air-blowing time and storage time on resin-dentin bond was material-dependent. CLINICAL RELEVANCE: Extended air-blowing time increased the bond strength and bond durability of CU. Extension of air-blowing time to 15 s and 30 s improve the long-term bond strength of SB and CU, respectively.


Assuntos
Ar , Resinas Compostas , Colagem Dentária , Adesivos Dentinários , Dentina , Cimentos Dentários , Humanos , Teste de Materiais , Dente Molar , Cimentos de Resina , Resistência à Tração , Fatores de Tempo
10.
Dent Mater J ; 37(6): 973-980, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30135339

RESUMO

The purpose of this study was to evaluate the effect of surface roughness and smear layer on the micro-shear bond strength (µSBS) of two self-etching adhesives, Clearfil SE Bond (SE) and Clearfil Tri-S Bond (S3). Flat dentin surfaces were prepared with SiC papers (600-, 180- and 120-grit) and diamond burs (extra fine, medium and coarse). They were further divided into smear-covered and smear-free surfaces and bonded with respective adhesives. µSBS test was performed after water storage at 37ºC for 24 h. Smear layer thickness measurement was evaluated by scanning electron microscope (SEM). Surface roughness was examined by contact stylus profilometer. Smear layer thickness and surface roughness were significantly different among all groups (p<0.05). No difference in µSBS was observed among surface prepared by SiC whereas bur-cut smear layer had negative effect on µSBS, especially for S3. Surface roughness from different surface preparations had no influence on µSBS (p<0.05).


Assuntos
Adesivos Dentinários/química , Dentina/ultraestrutura , Cimentos de Resina/química , Camada de Esfregaço , Colagem Dentária , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
11.
Eur J Oral Sci ; 125(6): 471-478, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29110340

RESUMO

This study evaluated the effect of topical fluoride application on enamel hardness after in-office bleaching. Twelve human incisors were cut along the long axis, resulting in 24 halves used in four treatment groups (n = 6 in each group): (i) untreated group (C); (ii) in-office bleaching material (B); (iii) treatment with surface reaction-type prereacted glass-ionomer varnish after in-office bleaching (B+PRG); and (iv) treatment with acidulated phosphate fluoride solution after bleaching (B+F). All specimens were subjected to pH-cycling for 4 wk. Knoop hardness was measured using a Cariotester. The decalcification of enamel was assessed quantitatively by measuring the integrated mineral loss (ΔIML). Games-Howell analysis was used to assess statistical significance of between-group differences. The Knoop hardness decreased significantly after bleaching for all groups. In treatment groups B+PRG and B+F, the Knoop hardness returned to the original unbleached values after the first pH cycle and did not change afterwards. In treatment groups C and B there was a gradual decrease in the Knoop hardness until the fourth pH cycle. The integrated mineral loss, ΔIML, was significantly higher in treatment group B+F after 2 wk than in the other treatment groups. After 4 wk, the ΔIML in treatment group B was significantly higher than in treatment group B+PRG. The application of fluoride-containing materials after bleaching results in recuperation of hardness to levels similar to those of unbleached enamel.


Assuntos
Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/diagnóstico por imagem , Fluoretos Tópicos/administração & dosagem , Peróxido de Hidrogênio/administração & dosagem , Microrradiografia , Clareamento Dental/métodos , Remineralização Dentária/métodos , Testes de Dureza , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Incisivo
12.
Dent Mater ; 33(8): 895-903, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28552335

RESUMO

OBJECTIVES: To evaluate the influence of different air-blowing durations on the micro-tensile bond strength (µTBS) of five current one-step adhesive systems to dentin. METHODS: One hundred and five caries-free human molars and five current one-step adhesive systems were used: ABU (All Bond Universal, Bisco, Inc.), CUB (CLEARFIL™ Universal Bond, Kuraray), GPB (G-Premio BOND, GC), OBA (OptiBond All-in-one, Kerr) and SBU (Scotchbond Universal, 3M ESPE). The adhesives were applied to 600 SiC paper-flat dentin surfaces according to each manufacturer's instructions and were air-dried with standard, oil-free air pressure of 0.25MPa for either 0s, 5s, 15s or 30s before light-curing. Bond strength to dentin was determined by using µTBS test after 24h of water storage. The fracture pattern on the dentin surface was analyzed by SEM. The resin-dentin interface of untested specimens was visualized by panoramic SEM image. Data from µTBS were analyzed using two-way ANOVA (adhesive vs. air-blowing time), and Games-Howell (a=0.05). RESULTS: Two-way ANOVA revealed a significant effect of materials (p=0.000) and air-blowing time (p=0.000) on bond strength to dentin. The interaction between factors was also significantly different (p=0.000). Maximum bond strength for each system were recorded, OBA/15s (76.34±19.15MPa), SBU/15s (75.18±12.83MPa), CUB/15s (68.23±16.36MPa), GPB/30s (55.82±12.99MPa) and ABU/15s (44.75±8.95MPa). The maximum bond strength of OBA and SUB were significantly higher than that of GPB and ABU (p<0.05). SIGNIFICANCE: The bond strength of the current one-step adhesive systems is material-dependent (p=0.000), and was influenced by air-blowing duration (p=0.000). For the current one-step adhesive systems, higher bond strengths could be achieved with prolonged air-blowing duration between 15-30s.


Assuntos
Luzes de Cura Dentária , Colagem Dentária , Dentina , Adesivos , Resinas Compostas , Cimentos Dentários , Adesivos Dentinários , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à Tração
13.
J Dent ; 47: 63-70, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26855030

RESUMO

OBJECTIVE: This study evaluated the effects of surface preparation and the application time of adhesives on the resin-dentine bond strengths with universal adhesives. METHODS: Sixty molars were cut to exposed mid-coronal dentine and divided into 12 groups (n=5) based on three factors; (1) adhesive: G-Premio Bond (GP, GC Corp., Tokyo, Japan), Clearfil Universal Bond (CU, Kuraray Noritake Dental Inc., Okayama, Japan) and Scotchbond Universal Adhesive (SB, 3M ESPE, St. Paul, MN, USA); (2) smear layer preparation: SiC paper ground dentine or bur-cut dentine; (3) application time: shortened time or as manufacturer's instruction. Fifteen resin-dentine sticks per group were processed for microtensile bond strength test (µTBS) according to non-trimming technique (1mm(2)) after storage in distilled water (37 °C) for 24h. Data were analyzed by three-way ANOVA and Dunnett T3 tests (α=0.05). Fractured surfaces were observed under scanning electron microscope (SEM). Another 12 teeth were prepared and cut into slices for SEM examination of bonded interfaces. RESULTS: µTBS were higher when bonded to SiC-ground dentine according to manufacturer's instruction. Bonding to bur-cut dentine resulted in significantly lower µTBS (p<0.000). Shortening the application time resulted in significantly lower bond strength for CU on SiC and GP on bur-cut dentine. SEM of fractured surfaces revealed areas with a large amount of porosities at the adhesive resin interface. This was more pronounced when adhesives were bonded with a reduced application time and on bur cut dentine. CLINICAL SIGNIFICANCE: The performance of universal adhesives can be compromised on bur cut dentine and when applied with a reduced application time.


Assuntos
Colagem Dentária/métodos , Adesivos Dentinários/química , Dentina/química , Preparo do Dente/métodos , Condicionamento Ácido do Dente/métodos , Adesivos , Equipamentos Odontológicos de Alta Rotação , Análise do Estresse Dentário , Dentina/efeitos dos fármacos , Adesivos Dentinários/farmacologia , Humanos , Dente Serotino/efeitos dos fármacos , Dente Serotino/ultraestrutura , Distribuição Aleatória , Camada de Esfregaço/química , Propriedades de Superfície , Fraturas dos Dentes/terapia
14.
Dent Mater J ; 34(1): 61-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25748460

RESUMO

The purpose of this study was to evaluate the microtensile bond strength (µTBS) of a newly developed resin cement, ECD-89 (ECD, Tokuyama Dental, Tokyo, Japan) to dentin and to observe the interfacial micromorphology by comparing with two commercial resin cements, Multilink Automix (MA, Ivoclar Vivadent AG, Schaan, Liechtenstein) and Panavia F2.0 (PF, Kuraray Noritake Dental, Tokyo, Japan). Flat dentin surfaces of human third molars were exposed using #600 SiC. After application of primer and cement to the dentin surface, each cement was applied and cured with light (light condition) or without light (dark condition). The teeth were sectioned to obtain beams (1 mm×1 mm) after 24 h of water storage. The mean bond strengths and SDs (MPa) were: ECD: 68.6±14.9, MA: 39.2±18.9, PF: 39.4±18.5 and ECD: 54.5±22.4, MA: 36.7±15.6, PF: 13.4±4.46 when cured in light and dark condition, respectively. In both conditions, ECD-89 showed statistically higher µTBS than the others.


Assuntos
Adesivos Dentinários/química , Cimentos de Resina/química , Humanos , Técnicas In Vitro , Teste de Materiais , Dente Serotino , Compostos de Organossilício/química , Propriedades de Superfície , Resistência à Tração
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