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1.
The tooth interface with resin-modified glass-ionomer cements (RM GICs) is poorly understood. This study examined the interface, especially with dentin. Cervical cavities in extracted teeth were restored with Fuji II LC, Vitremer, Photac-Fil, or a conventional GIC, Fuji Cap II. Fluorescent dye was placed in the pulp chambers for 3 hrs before the specimens were sectioned. Examination of the tooth/material interface with a confocal microscope showed that dye uptake by the restoration varied among materials. A "structureless", non-particulate, highly-stained layer of GIC was observed next to dentin in Fuji II LC. This layer varied in width, was prominent where the dentin tubules were cut "end-on" and in areas closer to the pulp, and was not seen adjacent to enamel. Vitremer showed minimal dye uptake, and the "structureless" layer was barely discernible. Photac-Fil showed more uniform uptake and absence of this layer. Cracking of enamel was also noted with these materials. The conventional GIC did not show any dye uptake, presence of a "structureless" layer, or enamel cracking. We elucidated the potential mechanisms involved in the formation of a "structureless" interfacial layer in Fuji II LC by studying the variables of cavity design, surface pre-treatment, water content of the tooth, time for it to develop, early finishing, and coating of the restoration. This layer, the "absorption layer", is probably related to water flux within the maturing cement, depending on environmental moisture changes and communication with the pulp in a wet tooth. The "micropermeability model" was useful in this study of the interfacial characteristics of RM GICs.  相似文献   

2.
This study compared the effects of different dentin surface treatments on the shear bond strengths of three adhesive systems. The adhesive systems included a resin-modified glass ionomer, Fuji II LC, and two dentin bonding systems, One Step and Scotchbond Multi-Purpose Plus. The surface treatments compared for each adhesive system were as follows: 1) the controls, which were conditioned, 2) air abrasion at 120 psi without conditioning, 3) air abrasion at 160 psi without conditioning, 4) air abrasion at 120 psi with conditioning, and 5) air abrasion at 160 psi with conditioning. The KCP 1000 Whisperjet was used for all air-abrasive specimens. Controls for each adhesive material (Fuji II LC, One Step, Scotchbond Multi-Purpose Plus) were bonded using manufacturers' recommendations. Results showed that air abrasion significantly lowered bond strength of the resin-modified glass ionomer, conditioned or nonconditioned (P < 0.01). Air abrasion alone significantly lowered bond strengths of the dentin bonding agent systems (P < 0.01). However, air abrasion plus conditioning of the dentin surface resulted in bond strengths that were similar to the conditioned-only specimens (P < 0.01).  相似文献   

3.
Previous studies of the bonding capabilities of glass-ionomer cements have concentrated on the use of in vitro testing conditions. Since early moisture contamination appears to have adverse effects on the physical properties of glass-ionomer cements, and with the probability of pulpally derived dentinal fluid being present under in vivo conditions, the objective of this study was to compare in vivo tensile bond strength with in vitro tensile bond strength of a glass-ionomer cement to dentin utilizing the same teeth under similar test conditions. A glass-ionomer lining cement was placed on freshly exposed labial dentin of the maxillary incisor on 10 Rhesus monkeys. Immediately following placement, an orthodontic button was placed over the cement and left undisturbed for 1 hour. The teeth were then extracted and stored in 100% relative humidity for 23 hours. An Instron testing machine was used to register in kilograms the force required to cause tensile bond failure of the cement. Identical methodology was then used on the same teeth for in vitro testing. The concluding results indicate that a statistically significant difference (P < or = 0.05) exists between in vivo and in vitro tensile bond strengths of the glass-ionomer lining cement and that the bond failure was cohesive in character for all cases both in vivo and in vitro. These findings suggest that clinically, tensile bond strengths of glass-ionomer cements to cut dentin can be expected to be weaker in vital teeth than in devital teeth.  相似文献   

4.
OBJECTIVES: Until recently, esthetic inlay restorations in posterior teeth have been limited to cavities surrounded by enamel. Dentin adhesive systems in combination with luting composites and light-cured resin-modified glass ionomer cements offer a possibility for bonding ceramic inlays to cavities when the cervical margin is in dentin. This study was designed to compare in vitro marginal integrity of ceramic inlays bonded to dentin to restorations placed in cavities with margins located entirely in the enamel. METHODS: In the present in vitro study, the sealing abilities of a dentin bonding agent/luting composite combination (Syntac/Dual Cement, Vivadent) and resin-modified glass ionomers (Photac Fil, Photac Bond, ESPE; Dyract, De Trey Dentsply; Fuji II LC, GC Dental Industrial Corp.; and Vitremer, 3M Dental Products) used as luting agents in cavities extending beyond the cemento-enamel junction, were compared to the sealing abilities of a conventional luting composite (Vita Cerec Duo Cement, Vita) in cavities within sound enamel. SEM analysis and dye penetration were performed to evaluate marginal integrity at the cervical cavity margins. RESULTS: The dentin bonding agent/luting composite combination (Syntac/Dual Cement) rendered a marginal seal within the dentin similar to the quality obtained with the conventional luting procedures within sound enamel. When three out of the five resin-modified glass ionomers were used as luting agents (Dyract, Fuji II LC and Vitremer), the results were comparable to those reported for the dentin bonding agents and the conventional method. SIGNIFICANCE: Light-cured resin-modified glass ionomer cements may be considered as an alternative to dentin bonding agents when the cavity margins of ceramic inlay restorations are within the dentin. However, further studies, e.g., wear resistance, must be performed.  相似文献   

5.
PURPOSE: To investigate the marginal adaptation of resin-modified glass ionomer cements in dentin cavities placed with or without additional application of resin bonding systems. MATERIALS AND METHODS: Three resin-modified materials (Fuji II LC, Photac-Fil, Vitremer), one compomer (Dyract) and as reference an adhesively bonded resin composite system (Gluma CPS-Pekafill) were used. Flat peripheral dentin surfaces on human molar teeth were produced by wet grinding on SiC paper. Cylindrical cavities, 3.5 mm wide, were prepared in these dentin areas and restored with the individual materials. Sixty cavities were pretreated and restored as requested by the respective manufacturers. Following water storage of the specimens for 15 minutes or 24 hours, excess was gently removed by wet grinding for microscopic inspection of the marginal area. Additionally, in 30 cavities an experimental one-component adhesive resin system, a proprietary dimethacrylate and HEMA mixture dissolved in acetone, was combined with each of the restoratives for evaluation after 15-minutes water storage. Finally, in six cavities each, Dyract was combined with Prime and Bond 2.0, and Vitremer with Scotchbond Multi-Purpose Plus for assessment after 15 minutes. Maximum marginal gap widths (MGW) were measured. One-way ANOVA by ranks (Kruskal-Wallis-Test) followed by Wilcoxon's Two-Sample test were used to study the statistical difference of MGW among the treatment groups at a rejection level P = 0.05. RESULTS: Neither the conventionally placed material systems nor the restorations in combination with adhesives showed consistently gap-free margins after 15-minute water storage. After 24-hour storage with Vitremer 4 of the 6 restorations were gap-free, whereas with all other materials only perfect margins were registered. There was, however, no significant difference between the groups. Application of the experimental and/or the specific resin bonding agents had no effect on early MGW except for the Photac-Fil group, which was significantly reduced.  相似文献   

6.
PURPOSE: To evaluate the 2-year clinical performance of two polyacid-modified resin composites and two resin-modified glass ionomers in Class V carious cavities. MATERIALS AND METHODS: A total of 120 Class V cavities were selected and 30 cavities were restored with one of two resin-modified glass ionomer materials (Fuji II LC Improved and Vitremer) and two polyacid-modified resin composites (Dyract and Compoglass) in Class V carious cavities after 2 years. The restorations were clinically evaluated after 1 and 2 years using the USPHS criteria. RESULTS: One-year findings revealed a significant difference in color match between Vitremer and other materials (P < 0.05) and no significant difference was found for the other criteria. Two-year results indicated a significant difference between resin-modified glass ionomers and polyacid-modified resin composite materials. The difference between Compoglass and Dyract was not statistically significant whereas the difference between Vitremer and Fuji II LC was statistically significant. Caries was not recorded at any evaluation period.  相似文献   

7.
The shear bond strengths of an amalgam (Permite C) and a gallium alloy (Galloy) to dentin, mediated by four dentin adhesives (Super-Bond D-Liner, Super-Bond D-Liner II, Paama 2, and Panavia 21), were investigated. Flat labial dentin surfaces were prepared from bovine lower incisor teeth. A 3 mm-in-diameter area of dentin was bonded according to each manufacturer's directions before placement of Permite C or Galloy. The bonds were stressed in shear at a crosshead speed of 1 mm/min. The mean shear bond strengths were analyzed using one-way ANOVA and Student's t-test, and fracture modes were assessed under X20 magnification and analyzed using Kruskal-Wallis and Mann-Whitney U tests. Scanning electron micrographs were taken of the bond interface of separate samples. The results showed no significant difference among the bond strengths of Super-Bond D-Liner (2.79 MPa, 2.69 MPa), Super-Bond D-Liner II (3.41 MPa, 2.65 MPa), and Paama 2 (0.70 MPa, 0.50 MPa) bonded to Permite C and Galloy (respective values in parentheses); however, Panavia gave a significantly better bond with Permite C (0.42 MPa) than with Galloy (0 MPa). Super-Bond D-Liner and Super-Bond D-Liner II gave stronger bonds than Paama 2 and Panavia with both Permite C and Galloy. For each dentin adhesive, there was no difference in fracture mode between Permite C and Galloy. It was concluded that, since all bond strengths were very low, none of the dentin adhesives tested would enhance the clinical retention of Permite C or Galloy. However, although the use of Paama 2 with Galloy was originally recommended by the manufacturer for dentin sealing purposes, no adhesion was claimed.  相似文献   

8.
PURPOSE: To investigate (1) the tensile bond strengths of four commercial dentin bonding systems to bovine crown and root dentin and (2) the structure of the hybrid layers for each system bonded to the two dentin substrates. MATERIALS AND METHODS: Superficial surfaces were exposed in bovine crown and root dentin. The teeth were embedded in plaster and a 3 mm diameter bonding area was demarcated. The four bonding systems used were All-Bond 2, Super-Bond D-Liner Plus, Clearfil Liner Bond II, and ProBond. Bonding procedures followed the manufacturers' instructions with the exception of Super-Bond D-Liner Plus where the primer was left in situ for 60 seconds. Tensile bond strengths were tested after 24-hour storage in 37 degrees C deionized water. Specimens were also prepared for SEM observation of the hybrid layer, after treatment with 10% phosphoric acid, and 10% phosphoric acid and 5% sodium hypochlorite. RESULTS: Statistically lower bond strengths to crown dentin when compared with root dentin were observed for All-Bond 2, whereas Liner Bond II showed the opposite (P < 0.01). Both ProBond and Super-Bond D-Liner Plus showed no statistical differences between crown and root dentin (P > 0.05). Hybrid layers could be observed for All-Bond 2, Liner Bond II and Super-Bond D-Liner Plus, with no apparent differences between the hybrid layers of crown and root dentin. In the case of ProBond, where the smear layer was not removed during the priming stage, it appeared that the primer had infiltrated and caused hybridization of the smear layer. The differences in bond strength were thought to be related to the different bonding mechanisms of each material, as well as possible variations in the crown and root dentin substrates.  相似文献   

9.
The strength of dental glass-ionomer cements will be influenced by defects present within its structure. This study measured the surface area porosity, percentage surface area porosity, and mean surface area of small bubbles (<0.01 mm2) and the surface area porosity, percentage surface area porosity and diameter of large bubbles within 40-microm-thick layers of four cements, using image analysis software. Two hand-mixed cements (Fuji I and KetacCem) and two capsulated cements (Fuji Cap I and KetacCem Maxicap) were viewed under transmitted light at x117.6 magnification. For each selected area (64.75 mm2) of each cement sample, five independent measurements were made of each of these parameters. Analysis of variance (ANOVA) indicated that there were no significant differences between the four cements in the small bubble parameters measured, whilst there were significant differences in the surface area porosity, percentage surface area porosity and diameter of the large bubbles. It was concluded that the hand-mixed cements tested had a greater number of larger diameter bubbles compared with the capsulated cements.  相似文献   

10.
This article reviews the current status and future prospects for glass-ionomer materials. These materials are of two chemical types: the older, self-hardening cements, which set by an acid-base neutralization reaction to give relatively brittle materials; and the newer, resin-modified cements, which set partly by polymerization and partly by neutralization. Compared with the self-hardening cements, the latter materials have improved esthetics, improved resistance to moisture, and greater toughness. Both types of glass-ionomer cement bond well to enamel and dentin and release a clinically useful amount of fluoride. They have been used in a variety of applications: as liners or bases, for luting of stainless steel crowns, for Class V restorations in permanent teeth, and for Class II and Class III restorations in primary teeth. The resin-modified glass-ionomers are particularly promising for these latter uses, although it is too early to be sure whether their long-term durability is sufficient. Self-hardening glass-ionomer materials are likely to retain specific niches of clinical application, including in their metal-reinforced and cermet-containing forms.  相似文献   

11.
The effect of sample thickness and dentin depth on bond strength of composite, compomer and resin modified glass ionomer have been investigated. The occlusal surfaces of 84 non carious human third molars were used for bonding. 4 subgroups were tested, superficial dentin with sample thickness 1 and 2 mm and deep dentin with sample thickness 1 and 2 mm respectively SBMP + /Z 100 composite showed 26 +/- 3.2, 22.3 +/- 4.5, 17 +/- 3.2 and 21.8 +/- 4.2 MPa shear bond strength to S. dentin 1 mm, deep dentin 1 and 2 mm and S. dentin 2 mm respectively. Compoglass reported 10.4 +/- 1.57, 9.1 +/- 2.3, 5.0 +/- 0.6 and 9.24 +/- 3.1 MPa while, Vitremer achieved 4.7 +/- 0.49, 3.2 +/- 0.39, 3.0 +/- 0.81 and 3.2 +/- 0.53 MPa. It is concluded that the highest bond strength can be achieved to superficial dentin in thickness or increments not more than 1 mm. And that both dentin depth and sample thickness might influence the quality of the bond to dentin with an effect that varies from one material to another depending upon the mechanism of bond of each material and its chemical composition.  相似文献   

12.
The pattern of water uptake into a polyacid-modified composite resin (compomer), Dyract (D), was assessed using gravimetric analysis and tritiated water absorption. The results were compared with a resin composite, Herculite (H), a resin-modified glass-ionomer, Fuji II LC (FL), and a conventional glass-ionomer, Fuji II (F). Samples were stored in tritiated water for periods varying between 6 h and 6 months. The resulting change in gravimetric weight and dimensions was recorded. The tritiated water content was then assessed using liquid scintillation counting and this was compared to the gravimetric changes. The inherent water content of each material was also established. D and H showed a slow steady net uptake to 3% and 1.3% weight by volume (WV) respectively at 6 months. FL showed a rapid uptake reaching 8.9% WV at 7 days and 9.3% WV at 6 months. F showed a steady, less dramatic water uptake reaching 5.3% WV by 6 months. For the glass-ionomer materials, values for gravimetric water uptake and tritium release differed due to the ongoing acid base reaction and an increase in firmly bound water. This phenomenon was noted in D suggesting evidence of a similar reaction in this material.  相似文献   

13.
This in vitro study evaluated the effects of etchant type, surface moisture, and resin composite type on the shear bond strength of dentin adhesives. Three adhesives which bond to etched dentin were used in the study: All-Bond 2, Amalgambond, and Clearfil Photo Bond. Occlusal enamel was removed from 200 human molars to expose dentin. The dentin surfaces were etched, treated with a dentin adhesive system, and bonded with resin composite. After thermocycling and storage, the composite columns were fractured from dentin using an Instron machine. Bond strengths were calculated and subjected to a statistical analysis. Etchant type, surface moisture, and resin composite type all had significant effects on dentin bond strengths. Overall, the highest bond strengths were obtained with 10/3 etchant, moist dentin, and hybrid composite. The highest bond strengths for All-Bond 2 and Amalgambond were obtained by using the manufacturer's recommended etchant, moist dentin, and a hybrid composite. The mean bond strengths for All-Bond and Amalgambond under these conditions were 22.5 and 19.0 MPa, respectively. Clearfil Photo Bond had significantly lower bond strengths, but was relatively unaffected by changes in experimental conditions.  相似文献   

14.
Glass polyalkenoate cements have the unique properties of physicochemically bonding to enamel and base metals and to leach fluoride over prolonged periods. These cements have been modified to provide a dual setting with both light activation and chemical cure to produce a more rapid set. This article reports a 12-month clinical trial of a light-activated glass polyalkenoate cement for the direct bonding of orthodontic brackets, compared with a standard composite bonding adhesive. There was no significant difference in failure rates of direct bonded orthodontic brackets cemented with Fuji II LC light-activated glass polyalkenoate cement (GC Industrial Co., Tokyo, Japan) (3.3%) compared with System I+ composite bonding resin (Ormco Corp., Glendora, Calif.) (1.6%).  相似文献   

15.
PURPOSE: To compare the shear bond strengths to dentin of four tooth-colored fluoride-releasing restorative materials that utilize different mechanisms of dentin-bonding. MATERIALS AND METHODS: Four materials were tested: a chemically-cured glass ionomer (Ketac-Fil); a light-cured resin-modified glass ionomer (Photac-Fil); a light-cured resin-modified glass ionomer in conjunction with a resin dentin-bonding agent (Vitremer); and a light-cured resin composite in conjunction with a resin dentin-bonding agent (Tetric). The enamel was removed from four sides of the twenty human noncarious extracted molars which had their roots embedded in acrylic blocks. Cylindrical samples of the materials were prepared in plastic molds and bonded to the dentin surface according to the manufacturers' instructions. After 24 hours of storage in a humidor, the samples were sheared with an Instron testing machine at a crosshead speed of 0.5 mm/minute. RESULTS: Statistical evaluation (ANOVA and Duncan's test) suggests that the fluoride-releasing resin composite material utilizing a resin dentin-bonding agent provided a significantly greater mean shear bond strength (16.5 MPa) after 24 hours storage than any of the selected glass ionomer materials. Of the three glass ionomer materials compared, the light-cured resin-modified material with a resin dentin-bonding agent provided a significantly greater mean shear bond strength (6.7 MPa) than the light-cured resin-modified material without a resin dentin-bonding agent (3.0 MPa) or the chemically-cured material (3.8 MPa).  相似文献   

16.
PURPOSE: Strong durable bonds between resin cements and metal alloys are critical to the success of resin-bonded, resin-veneered, or resin-retained prostheses. However, few comprehensive, comparative evaluations of materials or the fatigue effects of thermal cycling have been reported. The rate of strength loss may be a more important predictor of long-term success than bond strength. The purpose of this study was to investigate the effects of artificial aging by thermal cycling and resin cement type on the bond strengths to a base metal alloy. MATERIAL AND METHODS: This study investigated the effect of the number of thermal cycles (0, 1, 10, 100, 1,000, and 10,000) on the bond strengths of nine fixed prosthodontic resin cements. Specimens were assigned randomly to thermal cycle number/cement type test groups. Cylinders of a base metal alloy were bonded in an end-to-end configuration. One end of each bonded specimen was insulated, and the specimen was thermal cycled. Then, the bonds were tested in shear and bond strengths calculated. RESULTS: Two-way ANOVA revealed that the effects of cement type, the number of thermal cycles, and their interaction all significantly affected bond strength (p < .0001). Multiple range analysis showed that some cements had significant trends to lose bond strength with thermal cycling (p < .05), while others did not (p > .05). CONCLUSIONS: Both the type of resin cement and the amount of thermal cycling influenced bond strength to a base metal alloy. Some materials displayed more rapid loss of bond strength than others.  相似文献   

17.
The effect of the inclusion of aminobenzoic acid derivatives (ABAD) in a self-etching primer comprising 4-acryloxyethyltrimellitic acid (4-AET), HEMA and water on shear bond strength to ground dentin was investigated. The mean bond strengths to dentin were significantly increased by the inclusion of 0.307 mol% ABAD in the 4-AET/HEMA primer, when compared with the control (0 wt% ABAD) (p < 0.01). A particularly high value (38.0 MPa) of shear bond strength was obtained in the use of the primer containing p-nitroanthranilic acid (p-NAA). It seemed to assume that the effect of p-NAA could be caused by the strong electron-withdrawing group of -NO2. From SEM observation, it was found that bonding resin appeared to adhere strongly to the ground dentin without formation of any resin-tags in the dentinal tubules. It was thought that the ABAD with 4-AET/HEMA could perform facilitating photo-polymerization at the bonding interface, and resulted in increased bond strength to ground dentin, and that the bond strength could be affected by the electronegativities of substitutional groups of ABAD.  相似文献   

18.
PURPOSE: To evaluate a dental adhesive system that uses a single conditioning/primer agent. MATERIALS AND METHODS: Twenty-five flat enamel and dentin bonding sites were prepared to 600 grit on human molar teeth. The Clearfil Liner Bond 2 adhesive system was used to bond Clearfil AP-X composite to both enamel and dentin. After 24 hours of water storage, shear bond strengths were determined using an Instron testing machine. Fifty V-shaped cavity preparations were prepared in human molar teeth with an enamel and cementum margin. Composite restorations were placed using the new adhesive system. The teeth were stored for 24 hours, thermocycled, stained with AgNO3 , sectioned and examined for microleakage. SEM examinations were also completed to evaluate the effects of the treatment steps on enamel and dentin surfaces. RESULTS: Mean shear bond strengths for the experimental adhesive to enamel and dentin were 28.2 +/- 4.9 and 19.4 +/- 3.1 MPa. A t-test revealed that the enamel bond strength was significantly greater (P<0.05) than the dentin strength. No marginal leakage was observed from the enamel margins of the restorations. Three restorations showed minimal leakage from the cementum margins. SEM examinations showed resin penetration into both the conditioned enamel and dentin surfaces. The adhesive system produced high bond strengths to both enamel and dentin, exhibited very minimal microleakage and was easy to use.  相似文献   

19.
Previous studies have demonstrated the ability of the argon laser to polymerize light-activated materials and improve enamel shear bond strengths. This study was conducted to evaluate the effects of the argon laser on dentin shear bond strengths of current dentin bonding systems. Argon laser (HGM Model 8) at 231 and 280 mW, 5 sec bonding agent, 10 sec composite, and a conventional curing light (Translux EC/Kulzer) at 10 sec bonding agent, 20 sec composite were used to polymerize samples of dentin bonding systems [Scotchbond Multi-Purpose Plus (3M) and Prime Bond (Dentsply/Caulk), both with TPH (Dentsply/Caulk) composite]. A flat dentin bonding site (600 grit) was prepared on the buccal surface of extracted human teeth. Twelve samples were made for each set of parameters for both laser and conventional light totaling 48 samples. Samples were stored in distilled water in light-proof containers for 24 h at 37 degrees C. Shear bond strengths (MPa) were determined for each sample on the Instron testing machine. Mean values were calculated for each set of data and ANOVA with Fisher PLSD were used for statistical analysis. The argon laser provided bond strengths that were 21-24% greater than those of the conventional curing light system.  相似文献   

20.
Orthodontic bands often fail clinically at the band-cement interface. Hybrid ionomer and resin cements and a glass ionomer control were bonded to photo-etched and standard band materials, both of which were tested in as-received and air-abraded conditions. Cements were placed in a 3 mm diameter mold at the bonding interface and bonded to 6 x 6 mm stainless steel band specimens mounted to acrylic blocks. Specimens were stored in water for 24 hours at 37 degreesC and debonded in tension on a testing machine at 0.05 cm/minutes. Bond strengths (MPa) were calculated and data were analyzed by analysis of variance. Bond strengths to as-received bands were less than 3.4 MPa for cements tested, whereas bond strengths to air-abraded bands ranged from 7.1 to 17.7 MPa, except for the glass ionomer control. Air abrasion of band materials provides highly increased bond strength of hybrid ionomer and resin cements.  相似文献   

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