Effect of temperature on water sorption and solubility of dental adhesive resins

Objective

This study examined the effect of temperature on water sorption and solubility characteristics of four commercial dental adhesives. The null hypothesis tested was that temperature has no effect on the water sorption and solubility characteristics of these adhesives.

Methods

The tested materials were: three-step etch-and-rinse (All-Bond 2, AB), two-step etch-and-rinse (One-Step, OS), two-step self-etch (Clearfil SE Bond, SE) and one-step self-etch (Clearfil S3 Bond, S3) adhesives. Seven resin disks (6 mm in diameter × 1 mm in thickness) were prepared from each tested material and were stored in deionized water at 23 °C, 37 °C and 55 °C. Water sorption and solubility of the resin disks were measured before and after water immersion and desiccation following two consecutive sorption and desorption cycles. The water sorption and solubility values obtained were analyzed using two-way ANOVA and Tukey's multiple comparison tests. The relationships between maximum water sorption, solubility and kinetics of water diffusion with temperature were evaluated by means of Pearson correlation statistic.

Results

OS exhibited the highest water sorption and solubility values in the second sorption–desorption cycle at 55 °C (p < 0.001). This is followed by S3, SE and AB with no significant difference between SE and AB. Significant positive correlations were observed between maximum water sorption (r = 0.307, p < 0.01), solubility (r = 0.244, p < 0.05), water sorption (r = 0.651, p < 0.001) and desorption (r = 0.733, p < 0.001) diffusion coefficients (obtained using Fick's law of diffusion) with temperature in the second cycle.

Significance

High temperatures increased water sorption of simplified adhesives. Such water sorption may contribute to the failure of resin–dentin bonds.     

10种复合树脂颜色稳定性与吸水溶解性研究

目的 评价10种光固化复合树脂在不同溶液中的颜色稳定性及吸水溶解性能。方法 10种光固化复合树脂分别为：BeautifilⅡ(B2)、Ceram. X One Universal (CXU)、Charisma (CS)、Charisma Diamond (CD)、Denfil (DF)、DX. Universal (DXU)、Filtek Z250 (Z250)、Filtek Z350 XT (Z350)、FS-1 (FS)、Magnafill Putty(MP)。每种树脂材料各制作20个试件,随机分为4组(n=5),分别浸入蒸馏水(对照组)、咖喱、咖啡和红酒28 d,分光光度计测量试件浸入前及浸入后1、7、14、21和28 d的色度值(CIE L^*a^*b^*),计算染色前后色差值。根据ISO 4049:2019标准,每种材料制作3个试件,测量材料的吸水性和溶解性。采用三因素方差分析评估树脂材料、染液、染色时间对染色前后色差值(ΔE)的影响,采用单因素方差分析比较不同材料的吸水值和溶解值变化。结果 随着染色时间增加,所有试...     

Volumetric dimensional changes of dental light-cured dimethacrylate resins after sorption of water or ethanol.

OBJECTIVES: This study evaluated the influence of water and ethanol sorption on the volumetric dimensional changes of resins prepared by light curing of Bis-GMA, Bis-EMA, UDMA, TEGDMA or D(3)MA. METHODS: The resin specimens (15mm diameterx1mm height) were immersed in water or ethanol 37+/-1 degrees C for 30 days. Volumetric changes of specimens were obtained via accurate mass measurements using Archimedes principle. The specimens were reconditioned by dry storage in an oven at 37+/-1 degrees C until constant mass was obtained and then immersed in water or ethanol for 30 days. The volumetric changes of specimens were determined and compared to those obtained from the first sorption. RESULTS: Resins showed similar volume increase during the first and second sorptions of water or ethanol. The volume increase due to water absorption is in the following order: poly-TEGDMA>poly-Bis-GMA>poly-UDMA>poly-Bis-EMA>poly-D(3)MA. On the contrary, the order in ethanol is poly-Bis-GMA>poly-UDMA>poly-TEGDMA>poly-Bis-EMA approximately poly-D(3)MA. The volume increase was found to depend linearly on the amount of water or ethanol absorbed. SIGNIFICANCE: In the choice of monomers for preparation of composite resin matrix the volume increase in the resin after immersion in water or ethanol must be taken into account. Resins of Bis-EMA and D(3)MA showed the lowest values.     

Water sorption/solubility of dental adhesive resins.

OBJECTIVES: This study evaluated the water sorption, solubility and kinetics of water diffusion in commercial and experimental resins that are formulated to be used as dentin and enamel bonding agents. METHODS: Four commercial adhesives were selected along with their solvent-monomer combination: the bonding resins were of Adper Scotchbond Multi-Purpose (MP) and Clearfil SE Bond (SE) systems, and the "one-bottle" systems, Adper Single Bond (SB) and Excite (EX). Five experimental methacrylate-based resins of known hydrophilicities (R1, R2, R3, R4 and R5) were used as reference materials. Specimen disks were prepared by dispensing the uncured resin into a mould (5.8mm x 0.8mm). After desiccation, the cured specimens were weighed and then stored in distilled water for evaluation of the water diffusion kinetics over a 28-day period. RESULTS: Resin composition and hydrophilicity (ranked by their Hoy's solubility parameters) influenced water sorption, solubility and water diffusion in both commercial and experimental dental resins. The most hydrophilic experimental resin, R5, showed the highest water sorption, solubility and water diffusion coefficient. Among the commercial adhesives, the solvated systems, SB and EX, showed water sorption, solubility and water diffusion coefficients significantly greater than those observed for the non-solvated systems, MP and SE (p<0.05). In general, the extent and rate of water sorption increased with the hydrophilicity of the resin blends. SIGNIFICANCE: The extensive amount of water sorption in the current hydrophilic dental resins is a cause of concern. This may affect the mechanical stability of these resins and favor the rapid and catastrophic degradation of resin-dentin bonds.     

Influence of chemical and mechanical polishing on water sorption and solubility of denture base acrylic resins

Influence of polishing methods on water sorption and solubility of denture base acrylic resins was studied. Eighty samples were divided into groups: Classico (CL), and QC 20 (QC) - hot water bath cured; Acron MC (AC), and Onda Cryl (ON) - microwave cured; and submitted to mechanical polishing (MP) - pumice slurry, chalk powder, soft brush and felt cone in a bench vise; or chemical polishing (CP) - heated monomer fluid in a chemical polisher. The first desiccation process was followed by storage in distilled water at 37 +/- 1 masculineC for 1 h, 1 day, 1, 2, 3 and 4 weeks. Concluding each period, water sorption was measured. After the fourth week, a second desiccation process was done to calculate solubility. Data were submitted to analysis of variance, followed by Tukey test (p<0.05). Means of water sorption (%) and solubility (%), respectively, were: CL-MP: 1.92 and 0.02; CL-CP: 1.98 and 0.52; QC-MP: 2.31 and -0.05; QC-CP: 2.32 and 0.25; AC-MP: 2.45 and -0.07; AC-CP: 2.43 and 0.41; ON-MP: 2.32 and -0.06; ON-CP: 2.34 and 0.27. Mechanical polishing promoted significantly lower solubility of acrylic resins; initially, water sorption values were higher for chemically polished samples, however, after 4 weeks all groups were similar.     

抗菌涂层材料对义齿基托吸水性和溶解性与单体渗出的影响

目的研究义齿基托树脂表面抗菌涂层对基托吸水性和溶解性以及单体渗出的影响。方法根据YY 0270-2003 标准,测量4种基托树脂涂膜前、后的吸水值和溶解值,应用索氏提取法测量固化后基托树脂的交联度;利用气相色谱法测量基托树脂涂膜前、后的单体渗出量。采用SPSS17.0软件包对数据进行统计学分析。结果具有抗菌涂层的基托材料的吸水值、溶解值和单体渗出量明显减少。4种材料中,贺利氏树脂的交联度最高,日进和山八树脂次之,新世纪树脂最低。结论义齿基托树脂的吸水值、交联度和单体渗出量之间存在一定联系,即交联度较大时,吸水值减少,甲基丙烯酸单体渗出量也相应降低。抗菌涂层可以提高树脂基托的综合性能。     

Rheology of urethane dimethacrylate and diluent formulations.

OBJECTIVE: The purpose of this study was to measure the viscosity of resin formulations and investigate the relationship between diluent percentage and temperature. METHODS: Resin formulations were prepared using UDMA and either TEGDMA or HEMA, or HPMA, as diluents at different percentages. Viscosities were obtained with a Bohlin Rheometer at 23 degrees C for all formulations, and at 37 and 60 degrees C for selected formulations. RESULTS: The viscosity of the formulations exhibited Newtonian behaviour and decreased as the percentage of the diluent monomer increased, especially up to 40% of diluent. Linear regressions relating log(viscosity) and mass percent diluent, were obtained in the range 20-80% diluent. Viscosity also decreased as the temperature increased. Activation energies were calculated from Arrhenius plots, and ranged from 16.2-23.4 kJ mol-1. SIGNIFICANCE: The viscosity of the resins controls the flow properties and thus has a significant effect on the deployment of the respective monomers.     

Effects of 1,4-butanediol dimethacrylate and urethane dimethacrylate on HL-60 cell metabolism

The polymerization of methacrylic monomers present in dental composite resins never reaches completion and therefore the leakage of residual monomers into the oral cavity and into biological fluids can cause local and systemic adverse effects. This work was carried out to study the in vitro biochemical interactions of urethane dimethacrylate and 1,4-butanediol dimethacrylate monomers with HL-60 cells, a cell line assumed as an experimental model for simulating granulocyte behaviour. Our main finding was that both monomers induce cell differentiation at toxic concentrations and that cytotoxicity seems to be caused by alterations of glucose metabolism arising from mitochondrial dysfunction rather than from oxidative stress, which could not be altogether verified under our experimental conditions. Our study could be considered as a useful approach to investigate the biochemical mechanisms that contribute to the cytotoxicity of methacrylate compounds and it underlines the importance of assessing such parameters for testing biocompatibility in order to promote the development of better and safer dental materials.     

Alternative interpretations of water sorption values of composite resins

Water sorption values for direct filling resins and an unfilled resin were much more similar at 30 days when expressed as mg/g organic matrix than as mg/cm2 or weight percent. This interpretation is indicative of the water sorption characteristics of resin matrices. The values are even more indicative when solubility or leaching is taken into consideration. With the specimen sizes used in this study, the effect of the kinetics of water sorption could be minimized by using values obtained after immersion in water for 30 days.     

Correction to: The effect of functionalized titanium dioxide nanotube reinforcement on the water sorption and water solubility properties of flowable bulk-fill composite resins

The aim of this study was to investigate the effects of titanium dioxide nanotube addition on the water sorption and water solubility values of different composite resins. Titanium dioxide nanotubes were synthesized from titanium dioxide powder in anatase form and in 13 nm diameter by hydrothermal process and then functionalized with methacrylic acid. Characterization of the nanotubes was performed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. A flowable composite resin (Filtek Ultimate Flowable) and four flowable bulk-fill composite resins (Filtek Bulk Fill Flowable, SDR Bulk Fill Flowable, Venus Bulk Fill, X-tra Base) were tested. Two groups of each composite resin were prepared: groups of the resins without nanotubes; groups of the resins reinforced with 1.0 wt% functionalized titanium dioxide nanotube. Sorption and solubility in water were assessed according to ISO 4049 standards after 1, 7, 14, 21 days immersion periods. Data were analyzed using Mann–Whitney U and Kruskal–Wallis H tests (p  <  0.05). Long cylindrical tubular structures with a diameter of 41.09–72.49 nm were observed in electron microscopy analysis. The band at 1636 cm^− 1 showed the existence of the vinyl (C=C) bond of methacrylic acid coordinated to the nanotubes in Fourier transform infrared spectroscopy analysis. None of the materials tested in this study exceeded the maximum sorption and solubility values established by ISO. Regarding the water solubility, negative values were obtained. TiO₂ nanotube reinforcement decreased the water sorption and solubility values significantly at different evaluation periods in all composite resins except for Venus (p < 0.05).

     

Evaluation of ISO 4049: water sorption and water solubility of resin cements

The aim of this study was to evaluate the water sorption and solubility test design of ISO 4049 for resin cements. Sorption and solubility of six dual‐curing resin cements [RelyX Unicem 2 Automix (RUN), Multilink Speed CEM (MLS), Panavia SA Plus (PSA), RelyX Ultimate (RUL), Multilink Automix (MLA), and Panavia V5 (PV5)] were analyzed by storage in distilled water after dual‐curing. In addition, sorption and solubility during thermal cycling were assessed with self‐cured and dual‐cured specimens. After water storage, all cements revealed sorption in the range of 30 μg mm^?3 except for PV5, for which sorption was markedly lower (mean ± SD = 20.8 ± 0.4 μg mm^?3). Solubility values were negative for RUN and RUL (?2.1 ± 0.08 μg mm^?3 and ?1.9 ± 0.13 μg mm^?3, respectively). All other cements attained positive values in the range of 0.4–0.8 μg mm^?3. Thermal cycling effects were more pronounced. The assessment of water sorption according to ISO 4049 provides reliable results. Solubility results must be interpreted with care because absorbed water may distort the values.     

聚酰亚胺改性环氧树脂的合成方法

目的：自行合成聚酰亚胺,并用其对环氧树脂进行共混改性,探索改性的方法。方法以4,4’-氧双邻苯二甲酸（4,4'-Oxydiphthalic anhydride, ODPA）、4,4’-二氨基二苯醚（4,4'-Oxydianiline, ODA）、对苯二胺（p-Phenylenediamine, PPD）、降冰片烯二酸酐（5-Norbornene-2,3-dicarboxylic Anhydride, NA）为原料,进行聚酰亚胺的合成,利用傅立叶变换红外光谱分析,对其化学结构进行表征。将合成得到的聚酰亚胺与E-51环氧树脂共混,得到改性环氧树脂。结果合成的聚合物被确认为聚酰亚胺。合成所得低分子量聚酰亚胺可溶于环氧树脂,聚合后得到均一、透明的共混产物。结论成功合成低分子量的聚酰亚胺以及聚酰亚胺改性的环氧树脂。     

Sorption of water, ethanol or ethanol/water solutions by light-cured dental dimethacrylate resins

Objectives

This work is concerned with the study of the sorption and desorption process of water, ethanol or ethanol/water solution 50% (v/v) or 75% (v/v) by the dental resins prepared by light curing of Bis-GMA, Bis-EMA, UDMA, TEGDMA or D₃MA.

Methods

A thin resin disc is placed in a bath of time to obtain the sorption curve m_t = f(t). Then the liquid is desorbed until a constant mass for the disc is reached and the desorption curve is recorded. These experimental curves help in the determination of the sorbed/desorbed liquid amount at equilibrium, the percentage of the extracted mass of unreacted monomer known as “solubility”, and the sorption/desorption diffusion coefficient which expresses correspondingly the rate of the liquid sorption/desorption.

Results

The highest liquid uptake by dental resins was 13.3 wt% ethanol for Bis-GMA-resin, 12.0 wt% ethanol for UDMA-resin, 10.10 wt% ethanol/water solution for TEGDMA-resin, 7.34 wt% ethanol for D₃MA-resin and 6.61 wt% ethanol for Bis-EMA-resin. The diffusion coefficient for all resins was higher in water than in ethanol/water solution or ethanol. Bis-GMA-resin showed the highest diffusion coefficient (11.01 × 10⁻⁸ cm² s⁻¹) followed by Bis-EMA-resin (7.43 × 10⁻⁸ cm² s⁻¹), UDMA-resin (6.88 × 10⁻⁸ cm² s⁻¹), D₃MA-resin (6.22 × 10⁻⁸ cm² s⁻¹) and finally by TEGDMA-resin (1.52 × 10⁻⁸ cm² s⁻¹).

Significance

All studied dental resins, except TEGDMA-resin, absorbed higher amount of pure ethanol than water or ethanol water solution. TEGDMA-resin absorbed higher amount of ethanol/water solution (50/50 or 75/25 (v/v)) than water or ethanol. For all studied dental resins the diffusion coefficient was higher in water than in ethanol/water solution or ethanol.     

Long term water sorption and solubility of composite filling materials.

An investigation of the long term water sorption and solubility of four composites has been carried out. The findings show that all materials rapidly absorb water and at the same time there is a loss of material at a slower rate. Considerable variation in results is observed in the latter stages of the experiment. The possible causes of the variations are discussed.     

Fatigue resistance and stiffness of glass fiber-reinforced urethane dimethacrylate composite

STATEMENT OF PROBLEM: Retentive properties of cast metal clasps decrease over time because of metal fatigue. Novel fiber-reinforced composite materials are purported to have increased fatigue resistance compared with metals and may offer a solution to the problem of metal fatigue. PURPOSE: The aim of this study was to investigate the fatigue resistance and stiffness of E-glass fiber-reinforced composite. MATERIAL AND METHODS: Twelve cylindrical fiber-reinforced composite test cylinders (2 mm in diameter and 60 mm in length) were made from light-polymerized urethane dimethacrylate monomer with unidirectional, single-stranded, polymer preimpregnated E-glass fiber reinforcement. Six cylinders were stored in dry conditions and 6 in distilled water for 30 days before testing. Fatigue resistance was measured by a constant-deflection fatigue test with 1 mm of deflection across a specimen span of 11 mm for a maximum of 150,000 loading cycles. The resistance of the cylinder against deflection was measured (N) and the mean values of the force were compared by 1-way analysis of variance (alpha = .05). The flexural modulus (GPa) was calculated for the dry and water-stored cylinders for the first loading cycle. Scanning electron microscopy was used to assess the distribution of the fibers, and the volume percent of fibers and polymer were assessed by combustion analysis. RESULTS: The test cylinders did not fracture due to fatigue following 150,000 loading cycles. Flexural modulus at the first loading cycle was 18.9 (+/- 2.9) GPa and 17.5 (+/- 1.7) GPa for the dry and water-stored cylinders, respectively. The mean force required to cause the first 1-mm deflection was 33.5 (+/- 5.2) N and 37.7 (+/- 3.6) N for the dry and water stored cylinders, respectively; however, the differences were not significant. After 150,000 cycles the mean force to cause 1-mm deflection was significantly reduced to 23.4 (+/- 8.5) N and 13.1 (+/- 3.5) N, respectively (P < .0001). Scanning electron microscopy highlighted fiber- and polymer-rich areas within the specimens and indicated that individual fibers were well impregnated with resin. The combustion analysis studies identified the fiber content to be 35.9 vol%. CONCLUSION: The results of this study suggest that the fatigue resistance of the fiber-reinforced material examined was increased; however, the reduction in flexural modulus of fiber-reinforced composites may restrict their use where high rigidity is required, such as in removable partial denture clasps.     

Use of Hoy's solubility parameters to predict water sorption/solubility of experimental primers and adhesives

Self-etching primers and adhesives contain very hydrophilic acidic monomers that result in high water sorption/solubilities of their polymers. However, the chemical composition of these products varies widely. The purpose of this work was to vary the chemical composition of experimental self-etching primers and adhesives to determine if the water sorption/solubility of the polymers were affected in a predictable manner. The Hoy's solubility parameters of these mixtures were calculated to permit ranking of the degree of hydrophilicity of the polymers. Water sorption/solubility was measured according to ISO 4049. The results showed highly significant (R(2) = 0.86, P < 0.001) correlations between water sorption and Hoy's solubility parameter for polar forces (delta(p)) of the polymers. Similar correlations were obtained between polymer solubility and delta(p). When these results were compared with previously published results obtained with more hydrophobic resins, excellent correlations were obtained, indicating that Hoy's delta(p) values may be used to predict the water sorption behavior of methylmethacrylate polymers.     

Dynamic mechanical analysis of high pressure polymerized urethane dimethacrylate

Objectives

The aim of this study was to compare the viscoelastic properties of high pressure (HP) polymerized urethane dimethacrylate (UDMA) with those of control, ambient pressure thermo-polymerized and photo-polymerized, UDMA and to assess the effect of varying polymerization parameters (protocol, temperature, and initiator) on the viscoelastic properties of HP polymerized UDMA.

Methods

The viscoelastic properties of the two control polymers, polymerized under atmospheric pressure, and four experimental polymers, polymerized under HP, were determined via dynamic mechanical analysis (DMA), in three point bending configuration. Atomic force microscopy (AFM) was used to characterize fractured polymer surface morphologies.

Results

The results showed that: HP-polymerization lead to a polymer with significantly higher T_g and E′_rub, indicative of a higher crosslink density; modifying the polymerization protocol resulted in a significant increase in tan δ; increasing the polymerization temperature lead to a significant decrease in E′_rub and T_g; and that the polymer with no initiator had the lowest E′, E″, T_g, and E′_rub and the highest tan δ, suggesting that under this conditions a polymer with significantly reduced crosslink density had been obtained. A characteristic nodular appearance was seen for the two control polymers under AFM, while a modified surface morphology was present in the case of HP polymerized materials.

Significance

The DMA results suggest that polymerization under HP resulted in polymers with an increased crosslink density and that the higher polymerization temperature or the lack of initiator was detrimental to the viscoelastic properties determined. Changes in polymer network morphology were identified by AFM characterization.     

等离子体对软衬材料Soft Reverse吸水性和溶解性的影响

目的：探讨氩气等离子体表面处理对丙烯酸树脂类软衬材料Soft Reverse吸水率和溶解率的影响。方法：将软衬材料制成直径为30mm，厚为2mm的圆片62块，2块作红外光谱图分析。浸泡时间分别设定为1天、1周、1个月、6个月和12个月，每个浸泡时间均设对照组和实验组。所有标本在浸泡前称重，直至恒定重量，记录为m1。各组浸泡到预期时间后，1min内称重，记录为m2。将标本干燥处理后，反复称重直至恒定重量，记录为m3。吸水百分率（％）=（m2-m3）÷m1×100％；溶解百分率（％）=（m1-m3）÷m1×100％。结果：软衬材料Soft Reverse表面经氩气等离子体处理后C—H结构减少；标本浸泡1个月时，实验组的吸水率低于对照组，其余时间段实验组与对照组间吸水率无统计学差异；标本浸泡1天，1周和1个月，实验组的溶解率低于对照组，6个月和12个月实验组与对照组间溶解率无统计学差异。结论：氩气离子体表面处理只在短期（1个月）内对丙烯酸树脂类软衬材料Soft Reverse的吸水率和溶解率有降低效果。