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PubMedDate not supplied

Microtensile bond strength of different adhesive systems to primary and permanent dentin.

PURPOSE: The aims of this in vitro study were to: (1) compare bond strength of different adhesive systems to primary and permanent dentin using microtensile test; and (2) evaluate the interaction of these materials to primary and permanent dentin by means of scanning electron microscopy (SEM). METHODS: Middle-coronal dentin surfaces of 18 exfoliated primary and 18 extracted permanent molars were exposed and teeth were randomly divided, according to their adhesive system, into 3 groups (N=6 per group): (1) Clearfil SE Bond (SE); (2) One Up Bond F (OU); and (3) Single Bond (SB). Then, 5-mm high composite blocks were constructed. After bonding procedures, the teeth were stored in distilled water at 37 degrees C for 24 hours prior to the specimens' preparation. For the microtensile test, teeth (N=5 per group) were longitudinally sectioned into 2 axes rendering beam-specimens that were glued to special devices, which were mounted in a Universal Testing Machine to be loaded under a crosshead speed of 1 mm/min until fracture. One tooth of each group was prepared for SEM. RESULTS: Microtensile bond strength mean values (MPa) to primary/permanent dentin were: (1) SE=60.0/61.4; (2) OU=54.5/53.3; and (3) SB=70.1/64.9. Two-way analysis of variance (ANOVA) showed no significant differences (P>.05) for the bond strength values among primary and permanent dentin groups, neither among groups SExSB and SExOU. SEM images of SE and SB showed a well-defined, uniform, and continuous hybrid layer. A continuous hybrid layer, however, was not found for OU. CONCLUSIONS: Bond strength and micromorphologic characteristics of the adhesive systems evaluated were not influenced by the substrate. OU achieved worse results.

Adhesives↗
PubMed2006

SEM-morphology in dentinogenesis imperfecta type II: microscopic anatomy and efficacy of a dentine bonding system.

AIM: Dentinogenesis Imperfecta is a hereditary defect consisting of opalescent teeth composed of irregularly formed and undermineralised dentin that obliterates the coronal and root pulpal chambers. The aim of this study was to examine the morphology of permanent human enamel, dentine and the dentine-enamel junction, in individuals affected by Dentinogenesis Imperfecta type II in undercalcified sections using scanning electron microscope (SEM) to compare the findings to the normal morphology, and to study the efficacy of modern bonding system to dentine and enamel DI type II affected. MATERIALS AND METHODS: Four third molars extracted from two 19 year-old subjects (one patient affected by Dentinogenesis Imperfecta type II) were included in resin, two divided in slices with a air-cooled diamond disc, and two used to study the characterisation of the resin-dentin interface. The sections of the teeth were examined by means of SEM. The slices were finished up with abrasive paper (400, 600, 1000, and 2000), the half surfaces obtained were etched with 37% phosphoric acid and then joined up to the stubs for SEM analysis. SEM Stereoscan 440 Leica with magnifications of 20X, 100X, 250X, 1000X, 2000X, 3000X was used. As control group were used four third molars with normal anatomy. RESULTS: This study shows that the permanent enamel from patients with DI exhibits few structural changes. No relationships were found between enamel morphology and the DI type II. Enamel appeared to be regularly mineralised. The major findings were anomalies in the dentine-enamel junction, locally a lower degree of mineralisation and an undulating morphology. The dentine showed absence of tubules. CONCLUSION: This study confirms that the problem with teeth affected by DI type II is the defect in dentine and weakness in the way the enamel is attached to the dentine. The adhesive system tested is not able to create a real hybrid layer in dentine DI type II affected and seems to be less effective than on normal substrates.

Adolescent↗
PubMed2006

Bond strength of total-etch and self-etch dentin adhesive systems on peripheral and central dentinal tissue: a microtensile bond strength test.

OBJECTIVE: The purpose of this study was to evaluate the microtensile bond strength (mu TBS) of four total-etch adhesives [Excite (EB), Prime&Bond NT (PBNT), Single Bond (SB), and One Coat Bond (OCB)] by comparing them to five self-etching adhesives (Clearfil SE Bond (CSEB), Xeno III (X III), Prompt L-Pop (PLP), AQ Bond (AQB), and Tyrian/One Step plus (TOSP)] at different dentinal areas. In addition the interface between the adhesive resins and dentin was examined using scanning electron microscopy (SEM). METHODS AND MATERIALS: Superficial occlusal dentin of extracted human molars was exposed and finished with wet 800-grit silicon carbide paper. A block of composite resin was then bonded to the molar samples with the above adhesives according to the manufacturers' instructions. After 24 hours in water at 37 degrees C, the specimens were sectioned into 1 mm thick slices and divided into two regional subgroups according to their relationship to pulp tissue using visual criteria: pulp center and pulp periphery. The slices were then trimmed for the microtensile bond test and subjected to a tensile force and crosshead speed of 1 mm/min. Two-way analysis of variance was performed for statistical analyses. In addition the bond strengths for nine adhesive systems for each dentinal area were compared using the Post-Hoc test. The resin-dentin interfaces for each adhesive system were observed under a SEM. RESULTS: Mean mu TBS ranged from (25.2 MPa) for TOSP to (48.9 MPa) for PBNT. The bond strengths of total-etch adhesive systems were not significantly different, and were higher than self-etch adhesive systems, except for CSEB (p<0.05). No significant regional difference was observed for all of the nine adhesive systems (p>0.05). SEM observation showed there is not a standard hybridization for adhesive systems. CONCLUSION: Different dentinal areas may not exhibit as great an influence on bond strengths using new adhesive systems.

Acid Etching, Dental↗
PubMed2006

The influence of human plasma used for in vitro dentin perfusion on microtensile bond strength of 5 self-conditioning dentin adhesives.

OBJECTIVE: The aim of this in vitro study was to evaluate the effect of human plasma, compared to physiologic saline, on microtensile bond strengths of 5 self-conditioning dentin adhesives when used as a dentin perfusion medium. METHOD AND MATERIALS: One hundred and fifty extracted human third molars were prepared in a special manner allowing the simulation of intrapulpal pressure and dentin perfusion. The specimens were randomly divided into 10 experimental groups. Five groups were perfused with physiologic saline, while the others were perfused with diluted human plasma, each under constant hydrostatic pressure of 30 cm H2O. One saline group and 1 human plasma group was then assigned to each of the following dentin adhesives: Clearfil SE Bond (Kuraray), Clearfil Protect Bond (Kuraray), Xeno 3 (Dentsply), Futurabond NR (Voco), and iBond (Heraeus Kulzer). The microtensile bond strength for each group was evaluated using a Zwick universal testing machine 10 minutes after light curing. RESULTS: Pairwise comparison showed a significant increase of bond strength in all human plasma-perfused subgroups (P < .05, Tukey's test). The influence of the different dentin adhesives was significant (P < .001, analysis of variance). The highest significant values were observed for Futurabond NR and iBond with human plasma (P < .05, closed test procedure). CONCLUSION: The use of human plasma might be a suitable alternative to imitate perfused dentin conditions in testing devices and might eliminate the discrepancy between different in vitro investigations focusing on bond strength of dentin adhesives.

Dental Stress Analysis↗
PubMed2006

Bonding durability of a self-etching primer system to normal and caries-affected dentin under hydrostatic pulpal pressure in vitro.

PURPOSE: To evaluate the bonding durability of a self-etching primer system to normal and caries-affected dentin under hydrostatic pulpal pressure. METHODS: 18 extracted human molars with occlusal caries were used. Their occlusal dentin surfaces were ground flat to expose normal and caries-affected dentin using #600 SiC paper under running water. Clearfil SE Bond was placed on the dentin surface including the caries-affected dentin according to the manufacturer's instructions and then the crowns were built up with resin composite (Clearfil AP-X) under either a pulpal pressure of 15 cm H2O or none (control). The bonded specimens were stored in 100% humidity for 1 day (control) or for 1 week and 1 month with hydrostatic pulpal pressure. After storage, the specimens were serially sectioned into 0.7 mm-thick slabs and trimmed to an hour-glass shape with a 1 mm2 cross-section, isolated by normal or caries-affected dentin, and then subjected to the micro-tensile bond test. Data were analyzed by two-way ANOVA and Tukey's test (P< 0.05). RESULTS: Hydrostatic pulpal pressure significantly reduced the bond strength to normal dentin after 1-month storage (P< 0.05), but did not affect the bond strength to caries-affected dentin.

Analysis of Variance↗
PubMed2006

[In vitro cytotoxicity of different self-etching dental adhesive systems].

The study evaluated the cytotoxicity of five self-etching dentin adhesive systems applied on dentin specimens of different thicknesses. The test materials (A: Adper Prompt-L-Pop, B: Xeno II, C: Clearfil SE Bond, D: One up Bond F, E: Resulcin Aqua Prime & Monobond) and a positive control (35% H202) were applied on 1.0, 1.5 and 2.5 mm thick bovine dentin specimens (each subgroup n = 5) in a dentin barrier test device. The experiments were performed with perfusion (2 ml/h) of the pulpal part of the chamber. The eluates were obtained before (baseline) and 15, 30, 45, 60 and 120 min after application of the adhesives and pipetted onto L-929 fibroblasts. Cytotoxicity of the materials was determined in relation to the baseline value using the MTT assay and statistical analysis was performed by ANOVA. After 15 min perfusion, test materials B-E applied on 1.0 mm and B and E applied on 1.5 mm dentin specimens exhibited cytotoxic potential. However, after 30 min perfusion none of the adhesives showed any toxicity. Cytotoxicity decreased with increasing thickness of the dentin slices and was lower for Adper Prompt-L-Pop compared to adhesives B-E. Self-etching adhesive systems might exhibit cytotoxic potential when applied on dentin of less than 1.5 mm thickness. However, cytotoxicity of the materials decreased with increasing dentin thickness and increasing duration of perfusion.

Acid Etching, Dental↗
PubMed2006

HEMA diffusion from dentin bonding agents through various dentin thicknesses in primary molars.

PURPOSE: To evaluate in vitro HEMA diffusion amounts from three dentin-bonding systems in primary molars with various remaining dentin thicknesses. METHODS: Occlusal cavities were prepared with remaining dentin thickness of 0.5, 1 and 2 mm respectively. Chambers that contain 1 ml of distilled water were attached to each tooth. The groups were treated with Total Etch + Syntac Single Component, Syntac Single Component and Clearfil SE Bond. Water eluates were removed after 72 hours for analyses by HPLC. RESULTS: The cumulative HEMA release amounts were significantly different between all groups (P< 0.05). Decreasing dentin thickness and acid-etching significantly increased pulpward diffusion of HEMA.

Acid Etching, Dental↗
PubMed2006

Clinical performance and SEM evaluation of direct composite restorations in primary molars.

PURPOSE: To evaluate the clinical outcome of composite restorations performed in primary molars after 18 months and the morphology of the dentin/resin interface. METHODS: 41 primary molars from children aged 4-9 years were restored with Scotchbond Multi-Purpose Plus adhesive system and Z100 resin-based composite. The restorations were evaluated at baseline, 6, 12 and 18 months using the USPHS method for direct clinical analysis. Plaster models were made at each evaluation period for indirect evaluation. For the morphologic analysis of the dentin/resin interface, seven exfoliated teeth were sectioned longitudinally in a mesio/distal direction and observed in the electro scanning electron microscope. RESULTS: 100% (n = 40) of the restorations evaluated at 6 months were scored as Alpha for anatomical form, color matching, secondary caries, color alteration, and marginal degradation. At 12 months, 96.4% (n = 28) of the restorations received Alpha score and 3.4% Charlie score. At 18 months, all restorations evaluated (27/27) received Alpha score. 23 restorations were indirectly evaluated at 6, 12 and 18 months postoperatively. No significant wear or fractures were observed in any of the restorations. In the evaluation of the dentin/resin interface, the formation of a consistent hybrid layer was observed and the restorations were well adapted to the dentin at 18 months postoperatively.

Acid Etching, Dental↗
PubMed2006

Bond strength and failure patterns of adhesive restorations in primary teeth aged in the oral environment.

PURPOSE: To evaluate the bond strength and micromorphology of the fracture pattern of adhesive composite restorations in primary teeth after long-term clinical function. METHODS: Subjects (8-10 years-old) with deep carious lesions in primary molars had their teeth restored with resin composite (Z250). The teeth were randomly divided into two groups, according to the adhesive system used: (1) Scotchbond Multi-Purpose (SMP); and (2) Clearfil SE Bond (CSE). After the clinical and radiographic follow-up period (15-17 months), the teeth were exfoliated and the adhesive restorations were subjected to microtensile bond test. RESULTS: Student's t-test revealed a statistical difference (P= 0.001) between the two adhesive systems tested (SMP = 16.8 +/- 2.62 MPa; CSE = 27.3 +/- 2.28 MPa). The micromorphology evaluation of the failure zone revealed a weak area in the demineralized dentin (SMP) and at the top of the hybrid layer (CSE).

Child↗
PubMed2006

Microleakage of seven adhesive systems in enamel and dentin.

AIM: The aim of this study was to evaluate the microleakage of seven adhesive systems on two substrates (enamel and dentin). METHODS AND MATERIALS: Class V cavities were performed in buccal and lingual surfaces of 56 bovine incisors. The cervical margin was located in dentin and the incisal margin in enamel. The specimens were randomly divided into seven groups (n=16), according to the adhesive system employed: Single Bond; Excite; One Step Plus; Gluma One Bond; Magic Bond; One Up Bond F; and One Coat Bond. The cavities were incrementally filled with a hybrid composite Filtek Z250 and polymerized with a XL 3000 light curing unit. After polishing, the specimens were submitted to thermal cycling followed by dye immersion. Leakage was evaluated under magnification (40X) based on a standard ranking. Data were subjected to statistical analysis (Kruskal-Wallis). RESULTS: Enamel margins exhibited lower leakage than dentin margins (p<0.01). The majority of the specimens were leakage-free and materials performed similarly. Conversely, in dentin most of the specimens exhibited the highest leakage degree and significant differences among materials (p<0.05) were found, with Excite exhibiting the lowest leakage degree. It was concluded enamel provided better sealing and the adhesive system was a significant factor only in dentin.

Adhesives↗
PubMed2006

Effect of the number of coats of simplified adhesive systems on microleakage of dentin-bordered composite restorations.

AIM: This study tested the null hypothesis that there is no difference on microleakage of dentin-bordered composite restorations using single or double coats of adhesive from one-bottle adhesive systems. METHODS AND MATERIALS: The enamel surface was removed from freshly extracted bovine teeth, and standardized Class V cavities (3 x 3 x 1.5 mm) were made at the cervical areas of buccal surfaces. Teeth were restored and grouped according to type of adhesive systems [Prime Bond 2.1 (PB2.1), Prime & Bond NT (PBNT), and Single Bond (SB)] and to the number of coats (one or two) to be used. The restorations were polished and immersed in a 0.5% aqueous solution of basic fuchsin for four hours. Teeth were then sectioned and the most infiltrated section of each tooth was selected under magnification, scanned, and quantitatively analyzed using a computer program. Data were analyzed using two-way analysis of variance (ANOVA) and Student-Newman-Keuls (a=0.05). RESULTS: Groups without filler content (PB2.1 and SB) showed no difference in microleakage using single or double coats. However, PBNT (with nanofiller) showed statistically less microleakage when only one coat was applied. The influence of the number of coats of the adhesive systems on dentin margin microleakage was material dependent. CONCLUSION: All adhesive systems demonstrated microleakage, however, it could be minimized using two coats of non-filled or one coat of a filled adhesive system.

Acetone↗
PubMed1995

Resin-dentin interface of Scotchbond Multi-Purpose dentin adhesive.

PURPOSE: To evaluate the interface between dentin, Scotchbond Multi-Purpose (SMP), and resin composite (Z100) using confocal fluorescence microscopy. MATERIALS AND METHODS: Novel techniques were employed to view and record at video rate the application of the SMP primer and adhesive onto the dentin surface. The subsurface morphology of the dentin/restorative interface was also studied. To facilitate this study, the components of the adhesive system were labeled with fluorescent dyes. RESULTS: In an ideal situation, the primer and adhesive penetrated the dentin tubules, a distinct hybrid zone was formed and a thin layer of adhesive was observed at the interfacial region. However, the primed dentin surface was sensitive to disruption by the adhesive application brush during its placement, so that parts of the primer layer could be incorporated into the adhesive. This disruption could only be seen using confocal microscopy and a fluorescence labeling technique. Delamination of the primer layer was not observed when the adhesive film was thinned by air blowing. The application of an air stream to the cavity surface increased the penetration of the primer and adhesive along the dentin tubules, but also increased the thickness of the adhesive within irregularities on the cavity surface and at the cavity line angle. The cause of the problems in the handling properties of SMP may be the difference in viscosity between the two components (primer and adhesive) at the adhesive interface.

Composite Resins↗
PubMed1994

Penetration of a dentin bonding agent into dentin.

PURPOSE: To examine how the priming agents of Scotchbond Multi-Purpose (SMP) influenced the wettability of collagen in the demineralized zone and hence the penetration and adaptation of its bonding monomers. MATERIALS AND METHODS: Freshly extracted bovine teeth were ground to dentin with SiC paper. SMP and Z100 resin were used. Shear bond testing was performed as well as scanning electron microscopic evaluation. RESULTS: In contrast to the manufacturer's instructions, a 26.3% increase in shear bond strength was obtained when a second coat of priming agent was applied. This increase was statistically significant at the 5% level of confidence. SEM examination of failed conventionally air dried (CAD) specimens showed the presence of voids in the demineralized layer. SEM examination of failed specimens prepared by a critical point drying (CPD) technique showed that these voids were filled with collagen fibrils. The CPD technique also clearly showed that collagen fibrils were incorporated in the unfilled resin. Although priming agents appear to facilitate the penetration of unfilled resin into the demineralized layer and the dentin tubules, areas of unincorporated collagen fibrils can be seen even after two or more applications of the priming agent.

Analysis of Variance↗
PubMed1994

Altered tissue contribution to interfacial bond strength with acid conditioned dentin.

PURPOSE: To measure the shear bond strength of resin composite to dentin using three fourth generation bonding agents in combination with three different acid treatments. One such treatment was followed by sodium hypochlorite. The purpose was to determine the contribution which the collagen rich, demineralized zone made to bond strength. MATERIALS AND METHODS: Three groups, representing (1) All Bond 2/BisFil, (2) Optibond Dual Cure/XRV and (3) Scotchbond Multi-Purpose/Z100, contained four sub-groups each comprised of 10 caries-free molar teeth whose dentin was exposed in a transverse mid-coronal plane. Dressed with 320 grit, wet silicon carbide paper, the dentin surface in each sub-group was conditioned with 10% maleic acid (15 seconds), 10% phosphoric acid (20 seconds), 2.5% nitric acid (60 seconds) and 10% phosphoric acid (20 seconds) followed by 5% sodium hypochlorite (120 seconds). The bonded resin composite assemblies were stored in water at 37 degrees C for 24 hours and then subjected to shear force at a crosshead speed of 5 mm/minute until failure. RESULTS: The mean and standard deviation values derived for the groups were not statistically different from each other (P < 0.05). It was concluded that the type of conditioning agent was not a factor in achieving optimal bond strength for the system tested. Furthermore, it was tentatively concluded that the collagen-rich zone offered no direct, quantitative contribution to the interfacial bond strength which is probably derived from complete resin diffusion into the porous, partially demineralized dentin below.

Acid Etching, Dental↗
PubMed1994

Long term sealing properties of Amalgambond under amalgam restorations.

The degree of microleakage at 14 days, 6 months and 1 year between Class V amalgam restorations lined with Copalite varnish or with Amalgambond was compared in this in vitro study. The restored teeth were subjected to cyclic occlusal loading, thermocycling procedures and then stored in a dye solution at the appropriate intervals. Dye penetration was assessed at the gingival and occlusal margins of the restorations. The results showed that with Amalgambond, there was significantly better sealing of the dentin tubules than with Copalite or unlined restorations (P < 0.001) at all times tested. Amalgambond showed significantly less microleakage as compared to unlined restorations (P < 0.01) at all time periods, and significantly less short-term (14 days) microleakage compared with the Copalite-lined group (P < 0.01).

Dental Amalgam↗
PubMedDate not supplied

Microporous dentin zone beneath resin-impregnated layer.

The purpose of this study was to investigate marginal microleakage by examining the resin/dentin interface using a cryo-SEM and a silver ion penetration method. Class 5 cervical cavities were restored using an adhesive resin system following treatment with 37% phosphoric acid gel. The cavity wall adaptation was observed using cryo-SEM to avoid specimen damage. This observation showed excellent marginal adaptation of material to cavity walls and no gap formation. However, silver ions had penetrated beneath the resin-impregnated layer when observed with conventional SEM images, which showed the leakage of silver ions between the resin and decalcified tooth structure without gap formation. This study suggests that the bonding monomers of Clearfil Photo Bond were not fully able to penetrate into the demineralized dentin after phosphoric acid etching, thus leaving a porous zone as a microleakage pathway beneath the resin-impregnated layer.

Acid Etching, Dental↗
PubMed1993

The long term durability of bond strengths to dentin.

The aim of this study was to investigate the durability, throughout one year, of tensile bond strengths (TBS) to bovine dentin using various commercial and experimental bonding systems. Specimens were stored in a controlled solution of ion-exchanged water containing plaster chips and sodium azide. From the results it was concluded that the changes in TBS were not uniform over time, but a significant decrease was usually observed. For Super Bond D-liner and KB-100, the TBS were the highest and exhibited remarkable stability over the test period. The mode of fracture was noted to vary depending on the treatment system used, and was independent of TBS. Generally, the fracture mode tended to show increases in adhesive/cohesive failures within the resin over time. Super Bond D-liner always exhibited adhesive type failure at the tooth interface, and later involved failure in the hybrid layer. KB-100 showed very little change in failure over one year, being usually adhesive between bonding resin and resin composite. The results from this study indicate the need to carry out durability studies for the basic evaluation of all bonding systems. It was shown that the use of a controlled storage solution is important.

Acid Etching, Dental↗
PubMedDate not supplied

Dentinal adhesive with composite restorations: a clinical and microstructural evaluation.

It is generally accepted that the application of dentin-enamel adhesive should involve not only the etched enamel but also the dentinal surface. For this purpose, new bonding agents requiring dentin etching and the combined use of bifunctional groups (Primers) as well as hydrophilic resins have been introduced. This study used scanning electron microscopy to analyze the relationship between dentin and fluid resin of three bonding agents. The results demonstrated that the adhesive monomers easily penetrated the etched dentin, sealing the dentinal tubules and creating a resin dentin interdiffusion zone (hybrid layer). As a result, the microleakage between dentin and resin composite restorations, responsible for postoperative tooth sensitivity, pulpal inflammatory reaction, and secondary decay, is greatly reduced.

Acid Etching, Dental↗