RESUMO
OBJECTIVES: This study aimed to evaluate the dentin bond performance of various resin luting cement (RLC) systems combined with universal adhesives in different luting strategies. MATERIALS AND METHODS: Three self-adhesive resin luting cements (SRLCs) were used with universal adhesives as primers. Twelve specimens per group were prepared to measure shear bond strength (SBS) under distinct luting strategies in etch-&-rinse and self-etch modes. Regarding luting strategies, the bonded specimens were categorized into four groups based on tooth primer application and the curing mode of the SRLC paste: (i) with light irradiation of the tooth primer (wL) + dual-cure mode (DC) of the SRLC paste, (ii) wL + self-cure mode (SC) of the SRLC paste, (iii) without light irradiation of the tooth primer (woL) + DC mode of the SRLC paste, and (iv) woL + SC mode of the SRLC paste. Specimens were also subjected to different storage conditions: 24 h in water (baseline condition) and 10,000 cycles of thermal cycling. RESULTS: Luting strategy, storage condition, and SRLC system type significantly influenced dentin SBS values in both etching modes. Notably, certain SRLCs exhibited significantly higher dentin SBS when the primer was light-irradiated compared with no primer irradiation. CONCLUSION: Most SRLCs demonstrated higher dentin bond strength with light-irradiated primers, suggesting potential enhancement of dentin bond performance via primer light irradiation.
Assuntos
Colagem Dentária , Análise do Estresse Dentário , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento , Cimentos de Resina/química , Colagem Dentária/métodos , Adesivos Dentinários/química , Propriedades de Superfície , Técnicas In Vitro , Cimentos Dentários/química , Dentina , HumanosRESUMO
OBJECTIVE: The color matching of single-shade resin composites after in-office whitening was investigated. MATERIALS AND METHODS: Four single-shade resin composites were used. A total of 35% hydrogen peroxide was used as the whitening agent. The resin composite was placed in a cavity of an artificially discolored bovine tooth. The color differences between the restoration and surrounding enamel before and after whitening were determined based on ΔE*ab, ΔE00, and ΔWID. The color stability, surface roughness (Sa), and surface gloss (GU) of the resin composite alone were also evaluated. Statistical analyses were performed using repeated-measures analysis of variance with the Tukey-Kramer test. RESULTS: Based on the 50:50% of perceptibility and acceptability thresholds of ΔE*ab and ΔE00, none of the resin composite restorations were clinically acceptable before or after whitening. Regarding ΔWID, although all resin composites showed "acceptable match" in the baseline, they showed "mismatch" after the third session of whitening. Most of the resin composites alone were stable in color against whitening. CONCLUSIONS: Although the single-shade resin composites failed to achieve the expected color matching on discolored teeth either before or after the whitening, the impact of the whitening on the color of the resin composite alone may be negligible.
RESUMO
OBJECTIVE: This controlled randomized clinical trial determined the whitening efficacy and the intensity and absolute risk of tooth sensitivity in dual whitening when prefilled at-home whitening trays were used between in-office whitening intervals. MATERIALS AND METHODS: An in-office whitening agent containing 35% hydrogen peroxide was used. A prefilled tray with a whitening agent containing 6% hydrogen peroxide was used for at-home whitening. Sixty-six subjects were randomly assigned to three groups. Group I: at-home whitening was performed 10 times between the in-office whitening treatments. Group II: at-home whitening was performed five times between the in-office whitening treatments. Group III: only in-office whitening was performed. The tooth color changes were evaluated using a spectrophotometer. A visual analog scale was used to express the pain intensity. RESULTS: All the groups showed increased ΔE*ab, ΔE00 , and ΔWID with increased whitening sessions. Group I at the 3rd whitening session showed significantly higher ΔE*ab, ΔE00 , and ΔWID than group III. Tooth sensitivity showed higher values up to 24 h after whitening. CONCLUSIONS: Although dual whitening with the prefilled tray and in-office whitening had higher whitening ability than in-office whitening alone, the intensity and absolute risk of tooth sensitivity was similar. CLINICAL RELEVANCE: The dual whitening might produce faster and stronger whitening effects than in-office whitening alone.
Assuntos
Clareadores , Sensibilidade da Dentina , Clareadores Dentários , Clareamento Dental , Humanos , Peróxido de Hidrogênio , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
The purpose of this study was to evaluate the immediate shear bond strength of resin composite luting systems to tooth with or without saliva contamination in different curing modes. The Knoop hardness number of the resin composite luting agents was measured. Four combinations of resin composite luting systems were used. The shear bond strength to bovine teeth was measured with and without saliva contamination in different curing modes at different storage periods. The Knoop hardness number of the resin composite luting agents was also evaluated. Significantly lower enamel and dentin shear bond strengths and Knoop hardness number values were observed in all resin composite luting systems at 5 min versus 24 h, regardless of the curing mode or saliva contamination. The influence of the curing mode of the resin composite luting systems on shear bond strengths and Knoop hardness number was dependent on material. For the saliva contamination conditions, only G-CEM ONE EM did not show any significant difference in shear bond strength among the groups with and without saliva contamination, regardless of curing mode, storage period, or tooth substrate. All the resin composite luting systems showed lower shear bond strengths and Knoop hardness number values immediately after setting.
Assuntos
Colagem Dentária , Animais , Bovinos , Resinas Compostas/química , Esmalte Dentário , Análise do Estresse Dentário , Dentina , Adesivos Dentinários/química , Teste de Materiais , Cimentos de Resina/química , Saliva , Resistência ao CisalhamentoRESUMO
To examine the effect of mold enclosure and chisel design on macro shear fatigue bond strengths of dental adhesive systems. The fatigue bond strength testing was conducted with two commercially available dental adhesive systems, (1) OptiBond eXTRa and (2) Scotchbond Universal, for bonding a resin composite (Filtek Supreme Ultra) to both enamel and dentin using a mold enclosure and a non-mold enclosure with a knife-edge and two sized notched-edge chisel assemblies for loading. As a loading reference for the fatigue testing, macro shear bond strengths of the adhesive systems to enamel and dentin were conducted using a mold enclosure and a knife-edge chisel assembly. The shear bond strengths with the mold enclosure using knife-edge chisel assembly did not exhibit a significant difference between the adhesive systems for either enamel or dentin. The fatigue bond strengths of bonded specimens demonstrated significant differences when comparing the mold enclosure and non-mold enclosure, but not between knife-edge and notched-edge chisel assemblies. The fatigue bond strengths of dental adhesive systems demonstrated significantly higher values when using mold-enclosed bonded specimens than a non-mold enclosure, regardless of type of chisel assembly.
Assuntos
Colagem Dentária , Adesivos Dentinários , Resinas Compostas/química , Cimentos Dentários , Dentina/química , Adesivos Dentinários/química , Teste de Materiais , Cimentos de Resina/química , Resistência ao CisalhamentoRESUMO
This study investigated the effect of the bonding agent application method on the dentin bond durability of a two-step adhesive utilizing a universal-adhesive-derived primer. The bonding durability of a universal adhesive was compared with those of two conventional two-step adhesives by shear bond strength testing after thermal cycling. The primer was applied (with or without phosphoric acid pre-etching), and the specimens were divided into three groups based on the bonding agent application method used as follows: (i) strong air-flow application, (ii) gentle air-flow application, and (iii) gentle air-flow + second bonding application. The shear bond strength was determined after thermal cycling. All the factors (bonding agent application method, adhesive system, and storage condition) significantly influenced the dentin shear bond strength both with and without phosphoric acid pre-etching. The specimens exposed to gentle air-flow showed a higher shear bond strength than did those exposed to strong air-flow and gentle air-flow + second bonding. The bond durability of the tested adhesive systems was influenced by the bonding agent application method, and this trend was material dependent. The G2-Bond Universal exhibited the same or greater dentin bond durability to the other two-step adhesive systems.
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Colagem Dentária , Adesivos Dentinários , Condicionamento Ácido do Dente , Cimentos Dentários , Dentina , Adesivos Dentinários/química , Teste de Materiais , Cimentos de Resina , Resistência ao CisalhamentoRESUMO
Little information is available about enamel wear caused by zirconia brackets, an inadvertent side effect of orthodontic treatment. The purpose of this study was to examine potential enamel damage induced by contact with zirconia brackets. Sliding and impact wear simulations were performed using bovine enamel specimens positioned at a 25° slant to a zirconium ball to determine wear behaviour. Different chewing patterns, tapping and grinding, were simulated. Specimens were profiled using confocal laser scanning microscopy, and the mean maximum depth and surface roughness were measured. Scanning electron microscopy was also performed. The mean maximum depth of wear values differed according to the number of mastication cycles, with a higher number of cycles producing higher depths of wear. The facet wear depth was significantly greater with the tapping pattern than with the grinding pattern. Scanning electron microscopic observation of the wear facets revealed that surface textures at the edges were rougher than those at the centre of all facets. The results of this study indicated that enamel wear was induced by contact with zirconia brackets during the early period of mastication, and that the patterns and number of cycles of mastication affected the wear progression of enamel.
Assuntos
Porcelana Dentária , Zircônio , Animais , Bovinos , Esmalte Dentário , Mastigação , Teste de Materiais , Propriedades de Superfície , Zircônio/efeitos adversosRESUMO
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 CisalhamentoRESUMO
The purpose of this study was to evaluate the bonding and wear properties of self-adhesive flowable restorative materials. Five self-adhesive flowable restorative materials were used. The study parameters were: (i) shear bond strengths; (ii) microleakage; (iii) occlusal wear; and (iv) qualitative evaluation of the bonding interface. The range of shear bond strengths of the materials was as follows: 7.4-12.2 MPa to ground enamel, 22.5-32.5 MPa to etched enamel, and 1.3-4.2 MPa to dentin. The microleakage scores of the materials did not show any statistically significant differences regardless of the presence or absence of etching. The wear facets on the materials showed 0.099-0.447 mm3 of volume loss and 148.6-365.3 µm maximum depth, with statistically significant differences between materials. Scanning electron microscopic images of the interfaces of the materials showed good adaptation regardless of substrate. The bonding and wear properties of self-adhesive flowable restorative materials were still limited and showed lower values than previously reported results for nanofilled composites with an adhesive system. Selective enamel etching can improve the bonding performance of these materials.
Assuntos
Cimentos de ResinaRESUMO
OBJECTIVES: The present study aimed to investigate the changes in the enamel bond strengths of universal adhesives in the early phase of specimen creation and evaluate the effect of double-layer application on enamel bond effectiveness using different etching modes. METHOD: Four universal adhesives, namely Clearfil Universal Bond Quick, G-Premio Bond, Scotchbond Universal, and Tokuyama Universal Bond, were used. Clearfil SE Bond two-step self-etch adhesive system was used as a comparison. Fifteen specimens per group were used for determining the shear bond strength (SBS) to bovine enamel in the etch-and-rinse or self-etch mode. The adhesive was applied to specimens in accordance with the manufacturers' instructions (single-layer application), or the adhesive was applied twice (double-layer application). The bonded specimens were stored in distilled water at 37 °C for 5 min or 1, 6, 12, or 24 h before SBS testing. The flexural properties of the resin composite Clearfil AP-X were measured for the same storage periods. RESULTS: All universal adhesives exhibited increased SBS values with prolonged storage periods regardless of the application technique or etching mode used. Double-layer application was associated with higher SBS values than single-layer application for most universal adhesives over the same storage period. CONCLUSION: Phosphoric acid pre-etching and double-layer application of universal adhesives resulted in increased enamel bond strength in the early phase of specimen bonding. CLINICAL RELEVANCE: Care should be taken when using universal adhesives in the self-etch mode for enamel bonding because the enamel adhesion is sensitive to the duration after filling.
Assuntos
Colagem Dentária , Adesivos Dentinários , Condicionamento Ácido do Dente , Adesivos , Animais , Bovinos , Cimentos Dentários , Esmalte Dentário , Teste de Materiais , Cimentos de Resina , Resistência ao CisalhamentoRESUMO
PURPOSE: To examine the effects of an ion-releasing filler-containing gel on the remineralization of dentin using optical coherence tomography (OCT). METHODS: Dentin slabs of bovine teeth were sliced and shaped into a rectangular form. Specimens were treated with undersaturated 0.1 M lactic acid buffer solution (pH 4.75) for 10 minutes and then placed in artificial saliva (pH 7.0). This procedure was repeated three times a day for 28 days. The dentin remineralization effects of a fluoride/S-PRG filler-containing gel (PRG) and a 38% SDF solution (SDF) on dentin slabs of bovine teeth were compared. After treatment, the dentin slabs were immersed in a 0.1 M lactic acid buffer solution and then placed in artificial saliva. This procedure was repeated three times a day for 28 days. OCT imaging was conducted on the selected location of the dentin surface. The peak intensity and width at 1/e² were recorded in each of the six areas on the sample and averaged. Each group had a sample size of 10. Knoop hardness number (KHN) measurements and scanning electron microscopy (SEM) observations were also conducted. The data for each group were subjected to a one-way repeated-measures ANOVA and Tukey tests (α= 0.05). The samples were also observed using SEM. RESULTS: The peak signal intensities of SDF and PRG decreased on day 7 and then slightly increased during the experimental period for the one-off application groups and then decreased for frequent-time application groups. Although the width at 1/e² in the untreated specimens decreased over the test period, SDF and PRG for the one-off application groups exhibited an increase in widths on day 7 followed by a slight decrease, whereas it increased for the frequent-time application groups. The average KHN of the dentin samples exhibited the same tendency as the width at 1/e². Closure of the dentin tubules and crystal precipitation were detected on the surface of both SDF and PRG groups. CLINICAL SIGNIFICANCE: S-PRG filler-containing gel might have the ability to prevent dentin demineralization and could be useful for the prevention of hard-to-access lesions. This material achieved remineralization of the demineralized root dentin and had the same remineralization ability as SDF in vitro.
Assuntos
Desmineralização do Dente , Animais , Bovinos , Dentina/diagnóstico por imagem , Fluoretos , Saliva Artificial , Tomografia de Coerência Óptica , Desmineralização do Dente/diagnóstico por imagem , Desmineralização do Dente/tratamento farmacológico , Remineralização DentáriaRESUMO
PURPOSE: To evaluate the influence of light irradiation on the clinical efficiency of an in-office whitening agent. METHODS: The in-office whitening agent (Opalescence Boost 35%) was used in this study. Two whitening regimens were evaluated on maxillary anterior teeth: (1) with light irradiation; and (2) without light irradiation. The ΔE*, changes of L*, a*, b*, and the best shade match on the central incisor before, immediately after, and 6 months after whitening procedures were evaluated using a dental spectrophotometer. RESULTS: The ΔE and shade had no significant differences with or without light irradiation. In addition, the ΔE, changes of L*, a*, b*, and shade did not change over 6 months after bleaching at a level detectable to the naked eye. The results suggested that the in-office whitening agent using 35% hydrogen peroxide without photocatalysts can improve tooth color with or without light irradiation for 6 months after whitening. CLINICAL SIGNIFICANCE: In office whitening using 35% hydrogen peroxide without photocatalysts should be considered as a good treatment option for vital teeth whitening.
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Clareadores Dentários , Clareamento Dental , Dente , Cor , Humanos , Peróxido de Hidrogênio , Clareadores Dentários/uso terapêuticoRESUMO
OBJECTIVE: This study investigated the dentin remineralization effect of the application of a functionalized tri-calcium phosphate (fTCP) dentifrice and a silver diamine fluoride (SDF) solution. MATERIAL AND METHODS: The materials used were: a fluoride-containing dentifrice with fTCP (fTCPï¼), a fluoride-containing dentifrice without fTCP (fTCP-) and a 38% SDF solution. Following treatment, the dentin slabs were immersed in a 0.1-M lactic acid buffer solution and then placed in artificial saliva. This procedure was repeated three times daily for 28 days. The propagation time of longitudinal ultrasonic velocities (UV) and the Knoop hardness (KH) of the samples were measured. The samples were also observed using scanning electron microscopy. RESULTS: The SDF and fTCPï¼ groups showed higher UV than the fTCP - group regardless of the application method. The F-SDF group at 28 days showed significantly higher UV (4121 ± 102 m/s) than the F-fTCP + group (3731 ± 65 m/s) (p < .05). The F-SDF group at 28 days showed significantly higher KH (47.4 ± 2.2) than the F-fTCPï¼ group (43.3 ± 1.0) and the F-fTCP - group (42.9 ± 2.1) (p < .05). Closure of the dentinal tubules and crystal precipitation was detected on the surface of the fTCPï¼ group to a greater extent than the fTCP - group. CONCLUSIONS: The fTCP-containing dentifrice and SDF solution effectively enhanced bovine dentin remineralization.
Assuntos
Dentifrícios , Animais , Cariostáticos , Bovinos , Dentina , Fluoretos , Fluoretos Tópicos , Humanos , Compostos de Amônio Quaternário , Compostos de Prata , Remineralização Dentária , UltrassomRESUMO
OBJECTIVE: To examine the effect of filler contentTo examine the effect of filler content on structural coloration of experimental flowable resin composites. OVERVIEW: Experimental composites containing spherical fillers and different filler contents (30, 40, 50, 60 and 70 wt%), a structural colored resin composite (Omnichroma), and a nanohybrid flowable resin composite (Gracefil LoFlo) were used. The optical characteristics of the specimens were measured on standard black and white backgrounds using a spectrophotometer under CIE D65 illuminant and the L*a*b* values were determined. The color matching abilities to artificial teeth were evaluated using the ΔE*ab and ΔE00 color difference formulas. One-way analysis of variance and Tukey's post hoc test were used. The spectral reflectance of experimental composites showed different trends in different backgrounds, plate thickness, and filler contents. In particular, higher spectral reflectance was observed on the white background at wavelengths ranging from 450 to 700 nm in both 1.5 and 3.0 mm plates when compared to the black background. The percent reflectivity tended to decrease with a decrease of the filler contents. The color matching abilities of the experimental composites improved with the increase in the filler contents. CONCLUSIONS: Structural coloration of the flowable resin composites were affected by the filler contents. CLINICAL SIGNIFICANCE: Clinical Significance: Higher filler contents might be needed to achieve the optimal color properties of structural colored flowable resin composites, thereby improving the restoration esthetics.
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Resinas Compostas , Cor , Teste de MateriaisRESUMO
OBJECTIVE: This study aimed to compare dentin bond durability under different degradation conditions between two etch-and-rinse (ER) systems and a universal adhesive in ER mode. METHOD: This study used a universal adhesive [Scotchbond Universal (SU)], a three-step ER adhesive [Scotchbond Multi-Purpose Plus (SM)], and a two-step ER adhesive [Single Bond Plus (SB)]. A phosphoric acid-etching agent was applied to bovine dentin prior to the application of either a primer or the adhesive. After acid etching, bonding procedures were conducted. The specimens were divided into three group classes: (1) subjected to 10,000, 30,000, or 50,000 thermal cycles (TC); (2) stored in distilled water at 37 °C for 6 months or 1 year (WS); and (3) stored in distilled water for 24 h (baseline). Shear bond strength (SBS) tests were conducted. RESULTS: SB showed a higher baseline SBS than the other adhesives. Defining the baseline SBS value for each adhesive system as 100%, TC groups ranged from 56.1 to 70.3% for SM, from 98.4 to 103.7% for SB, and from 120.3 to 126.7% for SU. WS groups ranged from 66.2 to 71.4% for SM, from 98.1 to 103.3% for SB, and from 102.5 to 118.1% for SU. CONCLUSIONS: Although SB showed relatively stable dentin bond performance under all degradation conditions, SM showed decreased dentin SBS with prolonged degradation. SU did not show any significant decrease in SBS from the baseline under any degradation condition. CLINICAL RELEVANCE: The universal adhesive showed comparable adhesive performance with the two-step ER adhesive.
Assuntos
Dentina , Condicionamento Ácido do Dente , Animais , Bovinos , Colagem Dentária , Adesivos Dentinários , Teste de Materiais , Resistência ao CisalhamentoRESUMO
PURPOSE: To evaluate the ability of a pencil-type transducer connected to a pulser-receiver to measure remaining dentin thickness (RDT). METHODS: A total of 24 freshly extracted bovine incisors were used to prepare dentin disks with certain thicknesses (0.5, 1.0, 1.5 and 2.0 mm). The thicknesses of the specimens were measured with an ultrasonic technique using a pencil-type transducer, and the data obtained were compared with the direct measurement obtained using a micrometer. The Bland-Altman comparison method and paired t-test were performed at a 0.05 significance level. RESULTS: The agreement between different measurement methods was analyzed to evaluate the inter-methodology variation. The Bland-Altman comparison method revealed a mean difference of 0.0098 ± 0.724 mm between the ultrasonic technique and the direct measurement, with the 95% Bland-Altman limits of agreement ranging from 0.1322 to 0.1517 mm. CLINICAL SIGNIFICANCE: Ultrasonic measurement using the pencil-type transducer may be a promising method to evaluate remaining dentin thickness.
Assuntos
Dentina , Ultrassom , Animais , Bovinos , Dentina/diagnóstico por imagem , Incisivo/diagnóstico por imagem , TransdutoresRESUMO
PURPOSE: To investigate the occlusal wear of bulk-fill and conventional flowable resin composites. METHODS: Four bulk-fill flowable resin composites: (1) Filtek Bulk Fill Flowable Restorative (FB); (2) G-ænial Bulk Injectable (GB); (3) SDR Flow+ (SD); and (4) Tetric EvoFlow Bulk Fill (TB), and four conventional flowable resin composites: (1) Clearfil Majesty IC (CM); (2) Filtek Supreme Ultra Flow (FF); (3) G-ænial Universal Flow (GF); and (4) Herculite XRV Ultra Flow (HF) were evaluated. Localized wear was simulated using 400,000 cycles in a Leinfelder-Suzuki (Alabama) device with a stainless-steel ball bearing antagonist. Volume loss and maximum depth of wear facets were measured using a Proscan 2100 noncontact profilometer in conjunction with analyzing software. Scanning electron microscopy observations were also conducted on the wear specimens. RESULTS: Simulated occlusal wear was significantly different (P< 0.05) among the materials tested. FF, GB and GF showed significantly less wear than the other tested resin composites. The rank order of volume loss and maximum depth was GF-GB-FF-FB-CM-HF-TB-SD. CLINICAL SIGNIFICANCE: Bulk-fill flowable resin composites showed a much wider range of wear properties than conventional flowable resin composites. Some composites of each type may be suitable for use in occlusal contact areas of posterior restorations, but care must be taken when selecting such a resin.
Assuntos
Atrito Dentário , Resinas Compostas , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de SuperfícieRESUMO
The purpose of this study was to evaluate whether surface wetness would influence the bonding effectiveness of universal adhesives in etch-and-rinse mode. All-Bond Universal (AB), G-Premio Bond (GP), Prime & Bond Active (PB), and Scotchbond Universal Adhesive (SU) were evaluated. Initial bond strengths and bond-fatigue strengths of universal adhesives to both wet and dry enamel and dentin in etch-and-rinse mode were determined. Scanning electron microscopy observations of the adhesive interfaces were also conducted. The bond-fatigue durability of universal adhesive to enamel in etch-and-rinse mode was influenced by the surface wetness, unlike that to dentin. The bond fatigue durability of AB and GP to dentin in etch-and-rinse mode was different depending on the surface wetness, unlike that of PB and SU. The thicknesses of the adhesive or hybrid layer of resin-dentin interfaces were not influenced by the surface wetness, but the length of resin tags in the wet group was longer than in the dry group. Some universal adhesives with the addition of specific components and optimization of water content can achieve stable bonds regardless of surface wetness, but the surface wetness of dentin is still a significant factor for universal adhesive bonding in etch-and rinse mode, unlike that of enamel.
Assuntos
Condicionamento Ácido do Dente/métodos , Adesivos/química , Colagem Dentária/métodos , Materiais Dentários/química , Adesivos Dentinários/química , Dentina , Propriedades de Superfície , Cimentos Dentários , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina/químicaRESUMO
The purpose of this study was to determine the immediate bond effectiveness of universal adhesives to unground and ground enamel surfaces in different etching modes, through shear bond strength (SBS) tests and scanning electron microscopy observations. Three universal adhesives, a conventional two-step self-etch adhesive, and a conventional single-step self-etch adhesive were compared. Human enamel specimens from lower anterior teeth were divided into four groups and subjected to the following treatments: (i) unground enamel in self-etch mode; (ii) ground enamel in self-etch mode; (iii) unground enamel in etch-&-rinse mode; and (iv) ground enamel in etch-&-rinse mode. Bonded assemblies were subjected to SBS testing. All the adhesives showed significantly higher SBS values in etch-&-rinse mode than in self-etch mode, regardless of whether enamel was unground or ground. The influence of the enamel surface condition on SBS was different in different etching modes. Without pre-etching, all tested materials showed lower SBS values in unground enamel than in ground enamel. In etch-&-rinse mode, no significant differences in SBS values were observed between unground enamel and ground enamel for any of the adhesives tested. Phosphoric acid pre-etching before application of self-etch adhesives to an unground enamel surface is essential to enhance initial enamel bond effectiveness.
Assuntos
Condicionamento Ácido do Dente , Colagem Dentária , Esmalte Dentário , Adesivos Dentinários , Adesivos , Cimentos Dentários , Humanos , Teste de Materiais , Cimentos de Resina , Resistência ao CisalhamentoRESUMO
PURPOSE: To evaluate whether surface moisture would influence the bonding effectiveness of universal adhesives in etch-and-rinse mode. METHODS: All-Bond Universal (AB), G-Premio Bond (GP) Prime&Bond Active (PB) and Scotchbond Universal Adhesive (SU) were evaluated. Shear bond strengths after 24 hours and 10,000 thermal cycles of universal adhesives to moist and dry enamel and dentin in etch-and-rinse mode were determined. Scanning electron microscopy observations of the adhesive interfaces were conducted. RESULTS: The bond durability of universal adhesive to dentin in etch-and-rinse mode was influenced by the surface moisture, unlike bond durability to enamel. The bond durability of AB and GP, but not PB and SU, to dentin in etch-and-rinse mode was different depending on the surface moisture. Surface moisture did not influence the thicknesses of the adhesive or hybrid layer of resin-dentin interfaces, but the length of resin tags in the moist group was longer than in the dry group. CLINICAL SIGNIFICANCE: Some universal adhesives, with the addition of specific components and optimization of water content, can achieve stable bonds regardless of surface moisture, but the surface moisture of dentin, although not enamel, is still a significant factor for universal adhesive bonding in etch-and rinse mode.