Objectives: This study was conducted to determine the influence of storage solution on the bond durability of three resin cements to bovine dentin over the period of 1
year.
Methods: Ten bovine ...dentin specimens were tested for shear bond strength with each material (Panavia
21, Kuraray Co.; BISTITE, Tokuyama Co; MASA Bond, Sun Medical Co.) and storage mode, listed below. Four storage environments were studied as follows: water changed every day for 1
year; water unchanged for 1
year; Phosphate Buffered Saline (PBS) changed every week over 1
year; PBS unchanged for 1
year. Ten teeth were also tested for each material at 1
day as a control. The mode of failure was classified after fracture of the bonds by SEM observation. The means of the bond strengths were compared statistically by two-way ANOVA and Fisher's PLSD test (
p<0.05). Results for the mode of fracture were analyzed using the Mann–Whitney
U test.
Results: Although there was no statistical difference in the mean bond strengths between the water and PBS storage solutions (
p>0.05) in all cements, the results for the shear bond strengths in the changed storage solution groups were significantly lower than those where the storage solution remained unchanged (
p<0.05). There were statistical differences between the 1
day results and the changed water groups among all cements (
p<0.05).
Significance: The storage condition influenced the long-term durability of dentin bonding with resin cements.
Objectives: This three-year study was conducted to evaluate the tensile bond strengths of a dual-cured bonding resin, with and without priming, to bovine dentin.
Methods: Superficial bovine dentin ...was conditioned with 37% phosphoric acid and left unprimed (control) or was primed with 5-NMSA. Clearfil Photobond (Kuraray Co., Japan) was placed and light-cured, a layer of Protect Liner (Kuraray Co.) was applied, cured, then covered with Photo Clearfil Bright (Kurary Co.) resin composite and cured. Bonds were stressed in tension to failure at 1 d, 1 mon, 3 mon, 6 mon, 1 y and 3 y after preparation. Ten specimens were made for each group. Results were analyzed using one-way ANOVA and Duncan's multiple range test. Visual and SEM observations determined mode of failure and were analyzed using the Mann-Whitney U-test. Separate 1 d and 3 y specimens were fractured across the bonded interface and observed using a Field Emission SEM. After observation, the photomicrographs were compared for visual qualitative changes between the two time periods.
Results: The control (non-primed) group showed only a small decrease in bond strengths over 3 y, but in the primed group, a significant decrease was observed (p < 0.05). The bond strength of the non-primed group (5.2 MPa) was less than the primed group (10.6 MPa) at 1 d (p < 0.01), but by 3 y, the bonds of both groups were similar, 4.3 MPa and 5.5 MPa, respectively. Fractography indicated that only adhesive failure occurred in the control group. Failure in the primed group was cohesive in dentin initially, but shifted to the base or top of the hybrid layer after 1 y. Field Emission SEM observations showed hybrid layer formation in the primed group, but minimal resin infiltration in the control group.
Significance: Initially greater bond strengths were obtained for the primed group compared to the unprimed group (p < 0.01). However, by 3 y, the bond strength had decreased markedly in the primed group (p < 0.01), being almost the same for both groups. It was concluded that priming may only be useful to achieve strong bonding in the short term. These results may have significant implications related to clinical longevity of restorations.
Objectives. The purpose of this study was to determine the effect of the cross-sectional area shape (cylindrical
vs. rectangular) and the bonding surface area on the microtensile bond strengths and ...stress distribution of four dentin adhesive systems (Scotchbond MP Plus, OptiBond FL, OptiBond Solo, One-Step). In addition, finite element analysis (FEA) models were developed to investigate stress distributions.
Methods. Extracted human molars were cut vertically and the occlusal enamel removed; one-half of the tooth was used for rectangular specimens, the other half for cylindrical specimens. The occlusal dentin was bonded according to the manufacturers' directions and covered with a block of resin composite. For the cylindrical specimens, the bonded dentin was shaped with a diamond bur on a lathe to produce specimens of area 1.1, 1.5 or 3.1
mm
2 at the bonded interface. The rectangular specimens were sectioned to obtain bar-shaped specimens, which were shaped to produce hour-glass shaped specimens with the same area as the round specimens. Bonds were stressed in tension at a speed of 1
mm
min
−1. The mean bond strengths were compared using two-way ANOVA, one-way ANOVA, LSD and Student's
t tests. The fractured surfaces were examined by scanning electron microscopy, and the frequencies of the fracture modes were compared using the Kruskal–Wallis and Mann–Whitney U tests. FEA models were created simulating the cross-sectional areas for bonding to determine the stress distribution.
Results. The 3.1
mm
2 bonding area groups showed significantly lower bond strengths than the 1.1
mm
2 bonding area groups (
p<0.05), except for the rectangular specimens using Scotchbond MP Plus and One-Step. Most cylindrical specimens of bonding area 1.1 or 1.5
mm
2 exhibited adhesive failure at the interface between the dentin and the adhesive resin. No differences were determined between cylindrical and rectangular specimens. The fracture mode matched the stress distribution patterns calculated from the FEA modeling.
Significance. The results indicate that the test methods using small surface areas produce higher bond strengths than those using larger surface areas, and that cross-sectional shape has little effect. This is probably a result of fewer defects occurring in the small-area specimens.
Background: Recent advances in enamel and dentine adhesive technology have resulted in the emergence of many new adhesive systems. Self‐etching bonding systems do not require a separate etching step ...and the newest systems are the “all‐in‐one” systems which combine etching, priming and bonding into a single application. This study reports laboratory enamel microshear bond strengths of a self‐etching priming and three all‐in‐one systems and also evaluates two different microshear bond test methods.
Methods: One hundred and nineteen enamel specimens were bonded (0.8mm diameter) with either Clearfil Protect Bond (Kuraray), Xeno III (Dentsply), G Bond (GC) or One‐Up Bond F (Tokuyama) using Palfique Estelite resin composite and stored in 37°C water for seven days. The microshear bond test method used either a blade or wire to apply the shear stress. Results were analysed with one‐way ANOVA and post hoc (Tukey) multiple comparison analysis.
Results: Clearfil Protect Bond demonstrated higher and more consistent bond strengths than Xeno III, G Bond or One‐Up Bond F. The wire method showed much greater reliability in results, with a coefficient of variation half that of the blade method.
Conclusions: All‐in‐one adhesives seem to be less reliable than the two‐step self‐etching priming adhesive when bonding to enamel. Test method can significantly affect results in the microshear bond test method.
Abstract Objectives To evaluate (a) the enamel microshear bond strength (MSBS) of a universal adhesive and (b) the effects of conditioning with a self-etching primer adhesive with/without prior ...bleaching and/or casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) application. Methods Thirty-five molars were cut into four sections, assigned randomly to four groups (no treatment; 16% carbamide peroxide bleaching; CPP–ACP-containing paste (Tooth Mousse, TM); bleaching and TM) and treated accordingly. Specimens were divided into two for bonding with either a self-etching primer (Clearfil SE Bond, CSE) or a total-etch adhesive (Single Bond, SB). Specimens for CSE bonding were subdivided for one of four preconditioning treatments (no conditioning; 30–40% phosphoric acid (PA); 15% EDTA; 20% polyacrylic acid conditioner (Cavity conditioner, CC) and treated. The adhesives were applied and resin composite bonded to the enamel using microtubes (internal diameter 0.75 mm). Bonds were stressed in shear until failure, mean MSBS calculated and data analysed using ANOVA with Tukey's HSD test ( α = 0.05). The modes of bond failure were assessed and classified. Results Two-way ANOVA revealed significant differences between treatments ( P < 0.0001), conditioners ( P < 0.0001) and a significant interaction between treatments and conditioners ( P = 0.001). One-way ANOVA revealed no significant differences in MSBS following any of the treatments for SB; following TM application for CSE without preconditioning; and significant differences in MSBS following bleaching with and without TM application for CSE. With preconditioning, applying PA before CSE post-bleaching and either PA or CC before CSE post-TM application, resulted in significant differences in MSBS ( P < 0.05). Conclusions The use of conditioners prior to bonding with the self-etching primer adhesive system on treated enamel may significantly improve bond strengths.
...the application time is extremely short and a strong air blast is needed to evaporate the solvent and spread the resin to a very thin layer. ...the constituents and method of application of G-Bond ...are somewhat different from many other self-etching priming systems. Because this all-in-one adhesive is a mild-etching system, there is the potential that bonding to the uncut enamel may not be optimal, as reported in literature.4-6 For this reason, the enamel margin was etched as recommended by the manufacturer, which evidently prevented enamel marginal staining.
Background
: Caries‐affected dentine is the common bonding substrate when treating a patient. At present, there are many methods used for caries removal. The aim of this study was to evaluate the ...microtensile bond strength of two adhesives (Clearfil Protect Bond and OptiBond Solo Plus Total‐Etch) to caries‐affected dentine after three different caries removal methods.
Methods
: Extracted carious human third molars were used and caries‐affected dentine surfaces were obtained from one of the three removal methods: (i) round steel bur in a slow‐speed handpiece; (ii) Er:YAG laser; or (iii) 600‐grit silicon carbide abrasive paper. Each of the adhesives was used to bond resin composite to the caries‐affected dentine according to the manufacturers' instructions. Hourglass‐shaped specimens were prepared and stressed in tension at 1mm/min. Data were analysed using two‐way analysis of variance and least significant difference test.
Results
: Clearfil Protect Bond showed significantly lower bond strength than OptiBond Solo Plus Total‐Etch after caries removal with round steel bur, but the opposite was found for specimens treated with silicon carbide abrasive paper. For laser‐treated dentine, no significant differences between the adhesives were revealed.
Conclusions
: Besides the differences in adhesives, different caries removal methods seem to influence resin adhesion to caries‐affected dentine.
This study determined the influence of dentine structure on the micro-tensile bond strengths between resin and dentine of two different dentine adhesive systems (Single Bond, 3M Dental Products, St ...Paul, MN; MF-102 (experimental self-etching primer), GC Corporation, Tokyo, Japan). The study was separated into two main parts: bond strength measurement and investigation of the bonding interface. Twenty-two human premolars were used for the bond strength measurement. Each tooth was cut vertically, separating the tooth into mesio-distal halves. One half of the tooth was used to bond to a surface perpendicular to the dentinal tubules and other half to bond to a surface parallel to the tubules. For each half, six locations of dentine were bonded. Each material was used in accordance to the manufacturer’s directions. Cylindrical hourglass-shaped specimens of 1.2mm diameter at the bonded interface were manufactured. The bonds were stressed in tension at a crosshead speed of 1mm/min. Mean bond strengths were compared using LSD, one-way ANOVA, and Student’s t-test. The fractured surfaces were examined under a scanning electron microscope, and the frequency of fracture modes was compared using the Kruskal-Wallis and Mann-Whitney U tests. For the investigation of the bonded interface, four teeth were prepared by the same procedure used for the bond test specimens. The bonded interfaces were observed after an acid–base treatment or fracturing across the bonded interface, prior to investigation with a field-emission scanning electron microscope. For Single Bond, the bond strengths for mid-root dentine were significantly lower than for other locations (p<0.05). For MF-102, there was no significant difference for all locations (p>0.05). MF-102 bonded well to all locations of dentine while Single Bond showed a porous zone at the base of the hybrid layer. The bonds were not influenced by tubule orientation. The results indicate that the bond for Single Bond may be affected by its ability to penetrate demineralised dentine in different locations of a tooth. The self-etching primer of MF-102 produces a good bond and is independent of the position on the tooth.
Background: This study aimed to evaluate the association between the fracture toughness of two nanofilled‐hybrid resin composites (Clearfil Majesty Esthetic CME, Kuraray Medical, Japan; Estelite Σ ...ES, Tokuyama, Japan) and their bond strengths to enamel and dentine mediated by a self‐etching primer system (Clearfil SE Bond CSE; Kuraray).
Methods: Twenty‐four permanent human molars were sectioned into enamel and dentine specimens and finished with 600‐grit silicon carbide paper, bonded with CSE and either CME or ES, for μ‐shear bond strength (μSBS) and μ‐tensile bond strength (μTBS). The specimens were tested until failure at a cross‐head speed of 1 mm/min, failure loads recorded, bond strengths calculated and results analysed using independent samples t‐tests. Eight single‐notched bar‐shaped specimens, 30 mm × 5.2 mm × 2.2 mm, were prepared for each resin composite and fracture toughness measured using four‐point bending at a cross‐head speed of 0.5 mm/min. Results were analysed using independent samples t‐tests.
Results: For μSBS and μTBS, there was no significant difference between the resin composites for enamel or dentine. The fracture toughness of CME was significantly higher than that of ES.
Conclusions: For both enamel and dentine, resin composite fracture toughness affected neither μTBS nor μSBS to enamel or dentine.
Background: The ion activity product for hydroxyapatite (IpHA) is a comprehensive parameter reflecting pH, calcium and phosphate ion concentration in saliva which govern the degree of saturation ...with respect to the dissolving tooth mineral. The aim of this study was to evaluate the relationship between quantitative assessments of salivary buffering capacity and IpHA in relation to cariogenic potential.
Methods: Stimulated whole saliva was collected from 33 patients, and the initial pH of samples was measured using a hand‐held pH meter. Then samples were titrated with 0.1 N HCl to evaluate buffering capacities and divided into three groups (high, medium and low). After measuring concentrations of calcium and phosphate ions in the samples, IpHA was calculated using the values of the ion concentrations and pH. Differences in the mean pH values, the concentrations of calcium, phosphate ions and logIpHA among three groups were analysed using the Kruskal Wallis and the Mann‐Whitney non‐parametric test, p < 0.05.
Results: After HCl 50 μL titration, there were statistical differences of the mean pH and IpHA among each buffering capacity group. Moreover, after 50 μL HCl titration, there was an excellent correlation between the buffer capacity and logIpHA.
Conclusions: The pH change for saliva after HCl titration has a significant influence on the rate of IpHA.
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