Effect of different application techniques on microshear bond strength of self-etch adhesives to dentin

Objectives: To investigate the effect of different self-etch adhesive systems application techniques: active or passive in a single or double layer on adhesive–dentin microshear bond strength.

Methods: Occlusal surfaces of 48 extracted human molars were ground to expose flat superficial dentin surfaces. Specimens were randomly divided into two main groups according to the tested self-etch adhesive system either: One-step self-etch (Adper^TM easy-one) or two-step self-etch (Adper^TM SE Plus). Each adhesive system was applied on the prepared dentin surfaces followed one of these techniques: (1) Passive application of a single layer, (2) Active application of single layer, (3) Passive application of double adhesive layer (with light curing in between), and (4) Active application of double adhesive layers. Resin composite was packed inside micro-tubes fixed on the bonded dentin surfaces and light cured for 40 s. All specimens were stored in artificial saliva either for 24 h or 3 months before testing. Microshear bond strength test was employed using a universal testing machine at a crosshead speed of 0.5 mm/min.

Results: Adper^TM SE Plus showed higher significant microshear bond strength in compared with Adper^TM easy-one. For both adhesive systems active application showed higher significant microshear bond strength to dentin than passive application. Double application of adhesive systems showed lower microshear bond strength than single application.

Conclusion: Active application of self-etch adhesives could improve the dentin microshear bond strength. Double application with curing in between the layers did not improve the bond strength to the tested adhesive.     

Effect of acidic monomer concentration on the dentin bond stability of self-etch adhesives

This study evaluated the effect of the concentration of acidic functional monomer on the dentin bond stability of a model two-step, self-etch adhesive system. Six self-etch primers were formulated using hydroxyethyl methacrylate (HEMA), 1,3-glycerol dimethacrylate phosphate (GDMA-P), ethanol and water. Different mass concentrations of GDMA-P were tested: 0, 15, 30, 50, 70 or 100% (primers labeled P_0-100). The pH of the solutions was measured. The bonding resin was composed of (di)methacrylates. Bond strength to bovine dentin was assessed through a microtensile bond test. The beam specimens were stored in distilled water, at 37 °C, for 24 h, 6 months or 1 year. Data were statistically analyzed and failure modes classified under magnification. The increase in acidic monomer concentration was associated with an exponential decrease in pH (R²=0.999; P<0.001). All specimens debonded prematurely for the primers P₀, P₇₀ and P₁₀₀. After 24 h, the bond strengths for P₅₀>P₃₀=P₁₅. After 6 months and 1 year, P₅₀=P₃₀>P₁₅. The bond strength after 6 months was similar to 24 h for P₁₅ and P₅₀, but significantly lower after 1 year. P₃₀ showed no differences in bond strength over the 1-year storage period. A predominance of mixed failures was detected for all primers at 24 h. After 6 months, P₃₀ and P₅₀ showed a predominance of adhesive failures. After 1 year, the predominant failure mode for all primers was cohesive within dentin. In conclusion, a mass fraction of 50% of phosphate monomer is a limit to be added to self-etch primers; a more stable longevity of the bonds was obtained with the primer with 30% of phosphate methacrylate.     

Prime-and-rinse approach for improving the enamel micro-tensile bond strengths of self-etch adhesives

The study investigated the effects of prime-and-rinse approach using 15% MDP (10-methacryloyloxydecyl dihydrogen phosphate)-containing primer on the enamel micro-tensile bond strengths (MTBS) of (ultra-) mild self-etch adhesives, enamel surfaces and enamel-resin interfaces. The buccal enamel surfaces of 69 human third molars were polished and randomly assigned to three groups: Group A (control, self-etch approach): Polished enamel surfaces were not further pre-treated. The enamel surfaces were acid-etched (Group B, (selective) enamel etching) or primed with 15% MDP-containing primer (Group C, prime-and-rinse approach) for 15?s and thoroughly water-sprayed. The enamel surfaces were applied with self-etch adhesives and placed with composite resins (Adper Easy One?+?Filtek Z350 (3?M ESPE); Clearfil S3 Bond?+?Clearfil Majesty (Kuraray-Noritake Co.); G Bond?+?Gradia Direct (GC); iBond?+?Charisma (Heraeus-Kulzer)), respectively. The specimens were prepared for MTBS test and scanning/transmission electron microscopy observations. Compared with group A, groups B and C produced significantly higher enamel MTBS (p?<?.01), regardless of the adhesives used. Groups B and C possessed similar enamel MTBS (p?>?.05). The SEM findings showed that smear layer remained on the polished enamel surface was completely removed by acid etching and almost completely removed by prime-and-rinse approach. The TEM microphotographs reveal that smear layer was detectable at the resin-enamel interface in group A, not in groups B and C. The novel prime-and-rinse approach using MDP-containing primer before the application of (ultra-) mild self-etch adhesives could greatly increase the enamel MTBS. That might be an alternative to selective enamel etching.     

Effect of saliva contamination on shear bond strength and microleakage of one-bottle etch-and-rinse and self-etch adhesives: scanning electron and confocal laser microscopic analyses

Purpose: To evaluate the effect of saliva contamination on shear bond strength, microleakage, and microstructure of the adhesive interface in two different adhesive systems by using scanning electron microscopy (SEM) and confocal laser microscopy (CLSM). Materials and methods: Randomly, 228 third molars were allocated to six groups for an etch-and-rinse adhesive One-Step Plus (Bisco Inc.) and a self-etch adhesive G Bond (GC Corp.): Group 1 – manufacturer’s instructions were followed; Group 2 – involved contamination and drying before adhesive application; Group 3 – involved contamination, washing, and blot drying before adhesive application; Group 4 – involved contamination, etching, washing, and blot drying before adhesive application; Group 5 – involved contamination and drying after adhesive application, followed by adhesive reapplication; Group 6 – involved contamination and washing after adhesive application, followed by adhesive reapplication. Shear bond strength was tested after specimens were stored in distilled water at 37?°C for 24?h. Specimens were evaluated under a stereomicroscope for microleakage. Dentin–resin interfaces were evaluated by SEM and CLSM. Results: Group 2 for One-Step Plus and Group 3 for G Bond showed significantly lower bond strengths than control groups. Microleakage values were significantly greater at dentin than at enamel margins for all groups. In Group 2, for both adhesive systems, the highest microleakage was observed at dentin margins. Further, dentin–adhesive interfaces were not uniform and gaps were found by SEM and CLSM. Conclusions: The SEM and CLSM images demonstrated high variability of dentin–resin interfaces among saliva-contaminated groups. Rinsing the saliva and re-applying adhesive might be the best way to reduce the effect of saliva contamination on bond strength and microleakage.     

Influence of radiant exposure on degree of conversion,water sorption and solubility of self-etch adhesives

The purpose of this study was to investigate the influence of the radiant exposure on the degree of C=C conversion (DC), water sorption (WS), and solubility (S) of the Clearfil SE Bond (CSE) and Filtek LS (LS) self-etch adhesive systems. The primer of the LS (LSP), and bond agents of the CSE (CSEB) and LS (LSB) were tested. Specimens were light-cured using a light-emitting diode (LED) at different radiant exposures (6.1, 12.2, 13.9, and 27.8 J/cm²). DC (n=10) was measured using Fourier-transform infrared spectroscopy (FT-IR). WS and S were determined according to ISO 4049. Data were subjected to two-way ANOVA and Tukey's test at pre-set alpha of 0.05. The highest DC was exhibited by LSP, followed by CSEB and LSB, all with statistical difference (p<0.001). The DC was increased with higher radiant exposure and extended light-curing time (p<0.001). LSB and CSEB showed the lower WS followed by LSP, all with statistical difference (p<0.001). CSEB and LSB presented no significance difference on the S values (p>0.05) and were lower than LSP (p≤0.05). The WS and S were not influenced by the different radiant exposures evaluated (p=0.9548 and p>0.05, respectively). The monomer conversion is related to improvement on the mechanical properties of resinous material, but these properties also depend on the polymer network structure formed.     

Effect of polymerization protocol on the degree of conversion of photo- and dual-polymerized self-etch adhesives

This study investigated the effect of different polymerization protocols on the degree of conversion (DC%) of various photo-polymerized and dual-polymerized self-etch adhesive resins. Five different photo-polymerized (All-Bond Universal, Bisco; G-ænial Bond, GC; Futurabond M+ LC, VOCO; Single Bond Universal LC, 3M ESPE and Peak Universal Bond, Ultradent) and four dual-polymerized self-etch adhesives (Futurabond U, VOCO; Gradia Core SE, GC; Futurabond M+ DC, VOCO and Single Bond Universal DC, 3 M ESPE) were tested. All adhesives were applied on potassium bromide pellets (KBr) following the manufacturer’s instructions. The KBr pellets were divided into 10 experimental groups for the photo-polymerized adhesives and 12 experimental groups for the dual-polymerized adhesives according to the two levels of the study, Level 1: polymerization protocol and Level 2: adhesive system. For the photo-polymerized adhesives, the adhesives were polymerized either at 1 or 10 mm from the KBr pellets. For the photo-polymerized adhesives, the adhesives were photo-polymerized either at 1 or 10 mm distance or polymerized chemically. The DC% of the unpolymerized and polymerized adhesives was assessed using Fourier transform infrared spectroscopy. Data were analyzed using two-way ANOVA to evaluate the effect of polymerization protocol, adhesive system, and their interaction on the DC% of the self-etch adhesives. For the photo-polymerized and dual-polymerized adhesives, one-way ANOVA and Tukey HSD post hoc test was used to evaluate the effect of adhesive system within each polymerization protocol and the effect of polymerization protocol within each adhesive for the dual-polymerized adhesives (p = 0.05). Student t-test was used to compare the effect of polymerization distances within each photo-polymerized adhesive. For both photo- and dual-polymerized adhesives, the polymerization protocol and adhesive system had a significant effect on the DC (p = 0.000). The interaction between the two factors (polymerization protocol and adhesive system) revealed also a significant effect on the DC% of the different adhesives (p = 0.000). Polymerization distance of 1 mm showed significantly higher DC% compared to 10 mm distance. When the dual-polymerized adhesives were left to set chemically, they showed the lowest DC% among all polymerization protocols. DC varied depending on the chemical composition of the self-etch adhesives. The tip of the polymerization device should be positioned as close as possible to the surface to achieve higher DC% of the tested adhesives. Photo-polymerization of the dual-polymerized self-etch adhesives is a mandatory step to improve their DC.     

UV固化胶粘剂在液晶显示器生产组装中的应用

介绍了UV固化胶粘剂在液晶显示器(LCD)组装中的应用，LCD生产中的主板密封、端口密封、接线粘接、临时定位、裸芯片的倒装玻璃涂覆等工序使用UV固化胶粘剂是最适宜的。     

航天胶粘剂的性能与应用

介绍了本单位研制的主要胶粘剂及其应用,包括聚氨酯、环氧树脂、有机硅,酚醛树脂、丙烯酸酯、碳硼烷、无机胶粘剂等100多种,广泛应用于火箭、卫星的结构和非结构件的粘接、套装、密封等,基本满足了航天产品对胶粘剂的需求。     

Preconditioning of epoxy film adhesives for bond strength improvement

The moisture level of two commercial overaged epoxy film adhesives has been controlled by drying under vacuum and/or exposure to humid atmosphere. Shear and peel bond strengths of the conditioned adhesives were evaluated. Predrying of the uncured adhesive under vacuum (3–5 mm Hg) at room temperature is shown to be very effective for bond strength enhancement. Additional humidifying/drying circles show the same effect but some irreversible degradation occurs and only partial improvement of adhesive bond strength is achieved.     

The sonic application of universal adhesives in self-etch mode improves their performance on enamel

The objective of this study was to evaluate the effect of sonic application of universal adhesives on the enamel microshear bond strengths (µSBS), in situ degree of conversion (DC) and etching pattern. Ninety-six extracted third molars were sectioned in four parts (buccal, lingual, proximal) and divided into 12 groups, according to the combination of 1) adhesive system (All-Bond Universal [ABU], G-Bond Plus [GBP], Prime&Bond Elect (PBE), and Scotchbond Universal Adhesive [SBU]), and 2) adhesive application mode (manual active etch-and-rinse [M-ER], manual active self-etch [M-SE], and sonic vibration self-etch [S-SE]). Specimens were stored in water at 37 °C during 24 h and tested at 1.0 mm/min (µSBS). DC was evaluated in the enamel-resin interfaces using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a field- emission scanning electron microscope. Data were analyzed with two-way ANOVA and Tukey's test (α = 0.05). S-SE application increased µSBS and DC for all universal adhesives when compared to M-SE (p < 0.05). S-SE application resulted in mean bond strengths that were statistically similar to those obtained with the respective ER application mode (p > 0.05). A deeper enamel-etching pattern was observed for all universal adhesives in the etch-and-rinse strategy. An improvement in etching ability was observed in S-SE application compared to M-SE application. In light of the improved performance of universal adhesives when applied sonically in SE mode, selective enamel etching with phosphoric acid may not be crucial for their adhesion to enamel. The sonic application of universal adhesives in self-etch mode may be a practical alternative to enamel etching.     

Survey of polyurethane adhesives

Polyurethane chemistry provides a means to ‘tailor’ adhesives to specific needs. This is being achieved by polyurethane technology at a cost of more sophisticated application/bonding equipment and a need for better control of raw materials and adhesive processing conditions.     

国内水性聚氨酯胶粘剂产品及应用现状

分析了国内水性聚氨酯胶粘剂应用现状,对国产水性聚氨酯胶粘剂与国外产品及溶剂型产品的使 用性能作了对比检测,指出国内产品的性能已经取得很大进步,完全可以满足使用要求,并对产品使用性能 的研究开发动向作了深入的讨论。     

Effect of different dentin adhesives and application modes on sealing ability of amalgam restorations

Purpose: The aim of the study was to evaluate the sealing ability of bonded amalgam restorations using different adhesive materials with different adhesive application methods including amalgam bonding application. Materials and methods: The prepared Class-V cavities were randomly assigned to four application groups of four tested dual-curing dentin adhesives (Scotchbond Multi-Purpose Plus, XP Bond, Xeno IV and Clearfil Liner Bond 2V), dual-curing resin-based cement (Panavia F2.0) and a control group (unlined amalgam). Group 1 adhesives were applied according to the instructions for direct light-curing, Group 2 chemical-curing mode was applied according to the manufacturer’s amalgam bonding instructions. Group 3 adhesives were first applied in light-curing mode, and then amalgam bonding adhesive was applied. Group 4 adhesives were first applied in chemical-curing mode, followed immediately by light-curing mode. After that, amalgam adhesive parts were applied; then, the amalgam was condensed and carved. After storage for 24 h in distilled water at 37 °C, restorations were finished and polished. The teeth were then thermocycled (500 cycles between 5 and 55 °C), and the specimens were examined for microleakage using methylene blue as a marker. Results: Compared to the control group, the adhesive application modes significantly reduced microleakage for both dentin and enamel margins (p < 0.05). In dentin margins of the adhesives tested, Group 4 showed the lowest leakage score. On the enamel margins for Scotchbond Multi-Purpose Plus and XP Bond, Group 1 showed the highest microleakage (p < 0.05). Conclusion: According to marginal sealing ability and ease of application, Group 2 was recommended for the etch and rinse systems, and Group 4 was also recommended for the self-etch systems under amalgam restorations.     

贴片胶的特性及其应用

主要介绍贴片胶的特性和使用方法，同时还介绍了点胶工艺的一般技术要求．并给出了典型温度曲线。     

Microtensile versus microshear bond strength between dental adhesives and the dentin substrate

This study evaluated the performance of different bonding tests on the bond strength of three adhesive systems to dentin. Forty-eight bovine incisors were used in the study, which were allocated in two groups according to the bond strength test performed: microtensile (µTBS) or microshear (µSBS). Also, each group was divided in three subgroups according to the adhesive system applied: Single Bond (SB), Prime & Bond (PB) and XP Bond (XPB) (n=8). The teeth were prepared according to each bond strength test protocol, and then the specimens were tested in an universal testing machine (EMIC). The data were submitted to two-way ANOVA (bond strength test and adhesive system type factors) and Tukey's post hoc test (α=0.05). The µTBS results were higher for all the adhesives when compared to the µSBS ones. Within the µTBS results, SB showed higher bond strength than PB and XPB, which showed similar adhesive performance among each other; within the µSBS results, all the adhesives presented similar bond strength values to dentin. The µTBS test detected differences between the adhesive systems evaluated; in contrast, the µSBS test was less discriminating in evaluating the adhesive performance of the materials tested.     

我国胶粘剂技术现状、发展趋势和应用前景

对国内一些主要胶种的技术现状和存在问题进行了综述,在此基础上分析了我国胶粘剂行业今后的发展趋势,并讨论了胶粘剂在木材、建筑、基础工程、汽车、涂料、制鞋、纺织印染等领域的需求和应用前景。     

The effects of self-etch bio-active dental adhesive systems on bacterial microleakage

The aim of this in vitro study was to evaluate the effects of bio-active and non-bio-active self-etch adhesive sytems on bacterial microleakage of class II box cavities with restoration margins in dentin. Two bio-active (Clearfil Protect Bond and F1 Bond II) and two nonbio-active (Clearfil SE Bond and Clearfil s3 Bond) adhesive systems were selected for the study. Eighty mesial and distal class II box cavities were prepared on fourty sound human third molar teeth. The teeth were then divided into four groups with 10 teeth in each group. Groups were restorated using different adhesive systems. The restored specimens were immersed into a culture medium containing streptococcus mutans for bacterial microleakage test. Serial sections of the specimens were used to evaluate the bacterial lekage by using light microscope. The data obtained from the test of bacterial microleakage was evaluated using 2-way mixed analysis of variance (p < 0.05). Statistical analysis showed significant differences between the groups (p < 0.05). Nevertheless it was observed that none of the tested adhesive systems including the bio-active ones were successfull in eliminating bacterial microleakage.     

The preparation and performance of high-temperature adhesives for graphite bonding

Two kinds of high-temperature adhesives (HTAs) were prepared. One was composed of phenol-formaldehyde (PF) resin and boron carbide (PF+B₄C), the other was composed of PF resin, B₄C and fumed silica (PF+B₄C+SiO₂). Graphite materials were bonded by the above adhesives and heat-treated at temperatures ranging from 200 to 1500 °C. The joining strength was tested at room temperature. The results show that the graphite joints exhibit satisfactory bonding strength and that ceramics fillers show a marked property modification effect. The strength of graphite joints bonded by PF+B₄C and PF+B₄C+SiO₂ adhesive and treated at 1500 °C are 9.3 and 17.1 MPa, respectively. The property modification mechanism of ceramics fillers is also discussed in this paper. A strong chemical bonding force is introduced at the bonding interface and the volume shrinkage is restrained, which can be responsible for the good adhesive properties of HTAs for graphite bonding.     

Synthesis of bromo‐cardanol novolac resins and evaluation of their effectiveness as flame retardants and adhesives for particleboard

The synthesis of bromo derivatives cardanolic novolac resins (BCNR) using infrared, thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, nuclear magnetic resonance ¹H and ¹³C methods was studied. The mechanism of thermal degradation of BCNR is proposed. It is shown, that particleboards manufactured using PU‐(BCNR) as an adhesive are materials with enhanced flame retardant properties, meeting the requirements of P7 class to EN 312 (especially durable moisture‐resistant particleboards) and the requirements of the emission class Super E0. The bromine in the structure of the cardanol‐containing polyurethane binder allows achieving both high physical and mechanical characteristics of the particleboards and resistance to flame. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45322.     

Sealing effectiveness of fissure sealants bonded with universal adhesive systems: influence of different etching modes

This study compared the sealing effectiveness of fissure sealants bonded to enamel with universal adhesive systems applied in self-etch (SE) or etch-and-rinse (ER) modes. Extracted human molars (n = 216), were randomly assigned into nine groups with respect to etching mode, adhesive system, and the sealant material used (Clinpro/3 M or Giomer-Based BeautiSealant/Shofu): (1) ER + Clinpro (Control); (2) SE/Single Bond Universal (SBU) + ClinPro; (3) ER + SBU + Clinpro; (4) SE/All Bond Universal (ABU) + Clinpro; (5) ER + ABU + Clinpro; (6) SE/Clearfil Universal Bond (CUB) + Clinpro; (7) ER + CUB + Clinpro; (8) SE + BeautiSealant Primer + BeautiSealant; (9) ER/BeautiSealant Primer + BeautiSealant. Following thermocycling (1000X) and storage in 0.5% basic fuchsin, microleakage was evaluated quantitatively on tooth sections using imageJ analysis toolkit, and the data were analyzed statistically. The ER Mode significantly reduced the microleakage of universal adhesives. The following statistical ranking was observed with regard to the sealing effectiveness: ER + SBU + Clinpro = ER + ABU + Clinpro = SE/SBU + Clinpro = ER + CUB + Clinpro > SE/ABU + Clinpro = SE/CUB + Clinpro > ER + BeautiSealant Primer + BeautiSealant = ER + Clinpro (Control) = SE/BeautiSealant Primer + BeautiSealant. While the tested universal adhesives showed less microleakage on pre-etched enamel, the sealing effectiveness of SBU under SE mode was similar to all universal adhesives under ER mode. In both ER and SE modes, the sealing effectiveness of the giomer-based sealant was comparable to the control group.