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Self-etch adhesives try to solve difficulties commonly associated with the clinical application of etch-and-rinse adhesives. Their application procedure is considered less time-consuming and, more importantly, less technique-sensitive. The main objective of this study was to determine the bonding effectiveness to and the interaction with enamel/dentin of three contemporary one- and two-step self-etch adhesives by microtensile bond strength testing (μTBS), Fe-SEM and TEM when compared to a control two-step self-etch and a three-step etch-and-rinse adhesive. The one-step self-etch adhesive, Adper Prompt (3M ESPE), scored the lowest μTBS of all experimental and control adhesives tested. Conversely, the two-step self-etch adhesives Clearfil SE (Kuraray) and OptiBond Solo Plus Self-Etch (Kerr) approached the values obtained by the three-step etch-and-rinse control (OptiBond FL, Kerr) when bonded to enamel and dentin. Ultra-morphological characterization showed that interfacial morphology and the pH of the self-etch primer/adhesive are strongly associated. The interaction with dentin varied from the formation of a submicron, hydroxyapatite-containing hybrid layer for the "mild" self-etch adhesive Clearfil SE to a 3-5 pan thick, hydroxyapatite-depleted hybrid layer for the "strong" self-etch adhesive Adper Prompt. The two-step serf-etch adhesives AdheSE and Opt[Bond Solo Plus Self-Etch presented with a hybrid layer with a hydroxyapatite-depleted top part and a hydroxyapatite-containing base part and were therefore classified into a new group of self-etch adhesives, namely "intermediary strong" self-etch adhesives. [ABSTRACT FROM AUTHOR]

Objective: To evaluate a total-etch three-step adhesive system's resin-dentin interfacial ultra-structure and microtensile dentin bond strength (uTBS) after multi-year storage in water. Methods: Resin composite crowns were formed on 600 grit Si-C flattened extracted human molars using a total-etch three-step adhesive system (Optobond FL, Kett) and a hybrid resin composite (Prodigy, Kerr). uTBS specimen were fabricated and placed in water with 0.5% chloramine T at 37°C until respective static load to failure testing at one-month, six-months and five-year storage. Failure models were determined by scanning electron microscopy. The interfacial ultrastructure of the resin-dentin interface was analyzed by transmission electron microscopy (TEM) at 48-hours and 44-months storage. uTBS was modeled with Weibull distribution for survival analysis and failure curve distributions were analyzed by the Wald chi-square statistic for significant differences at a=0.05. Results: The characteristic tensile strength at one month, six-months and five-year storage was 52.63, 14.77 and 23.57 Mpa, with a Weibull modulus of 3.04, 1.56 and 1.28, respectively. Failure distributions for all groups were significantly different (p<0.0001) with one-month > five-year > six-months. TEM interfacial morphology demonstrated hydrolytic degradation of hybrid layer components at 44-months storage. Significance: The decrease in tensile strength and changes in ultrastructure may be caused by water sorption and resultant hydrolytic degradation of the adhesive joint. [ABSTRACT FROM AUTHOR]

Bonding to tooth tissue can be achieved through an "etch&rinse," "self-etch" or "glass-ionomer" approach. In this paper, the basic bonding mechanism to enamel and dentin of these three approaches is demonstrated by means of ultramorphological and chemical characterization of tooth-biomaterial interfacial interactions. Furthermore, bond-strength testing and measurement of marginal-sealing effectiveness (the two most commonly employed methodologies to determine "bonding effectiveness" in the laboratory) are evaluated upon their value and relevance in predicting clinical performance. A new dynamic methodology to test biomaterial-tooth bonds in a fatigue mode is introduced with a recently developed micro-rotary fatigue-testing device. Eventually, today's adhesives will be critically weighted upon their performance in diverse laboratory studies and clinical trials. Special attention has been given to the benefits/drawbacks of an atch&rinse versus a self-etch approach and the long-term performance of these adhesives. Correlating data gathered in the laboratory with clinical results clearly showed that laboratory research CAN predict clinical effectiveness. Although there is a tendency to simplify bonding procedures, the data presented confirm that conventional three-step etch&rinse adhesives still perform most favorably and are more reliable in the long-term. Nevertheless, a self-etch approach may have the best future perspective. Clinically, when adhesives no longer require an "etch&rinse" step, the application time, and probably more importantly, the technique-sensitivity are substantially reduced. Especially "mild," two-step self-etch adhesives that bond through a combined micromechanical and chemical interaction with tooth tissue closely approach conventional three-step systems in bonding performance. [ABSTRACT FROM AUTHOR]

This study compared the color stability of a conventional glass ionomer (Ketac-Fil), a light polymerized resin-modified glass ionomer (Photac-Fil), a polyacid-modified resin composite or compomer (Dyract) and a microfilled resin composite (Silux Plus). Thirty-two specimens (n=8/material) were fabricated and stored in artificial saliva at 37°C for seven weeks. A colorimetric evaluation, according to the CIE L*a*b* system, was performed at 24 hours (baseline) and at the end of each week. Color difference values (ΔE*ab) were calculated. The conventional glass ionomer, resin-modified ionomer and compomer materials underwent significant color changes over time (p<0.01). Those materials darkened and showed color shifts in both the red-green and yellow-blue axes. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of four methods of metal surface preparation and the use of silane on the bond strength between resin and a Noble metal alloy. SEM Examination and x-ray energy-dispersive spectroscopy (EDS) of the various metal surface treatments was also performed. One-hundred metal disks were cast in a Noble metal alloy (Porcelain #76). Ninety disks were polished fiat and the surfaces received one of four abrasive treatments (n=20). 1) Roughening with a diamond bur at high speed; 2) Air abrasion with an intraoral sandblaster using alumina particles; 3) Air abrasion with KCP-2000 and 4) Air abrasion with an intraoral sandblaster using silanated silica covered alumina particles (CoJet-Sand). Half the specimens from each treatment group (n=10) were silanated prior to bonding procedures (All-Bond 2 adhesive system, Pertac-Hybrid composite). Specimens were stored in distilled water at 37°C and thermocycled prior to shear strength testing. The 10 remaining metal disks were used for scanning electron microscopy and x-ray energy-dispersive spectroscopy (EDS). Scanning electron microscopy examined the micromorphology of the metal surfaces produced by the four abrasive treatments and x-ray energy-dispersive spectroscopy (EDS) to evaluate changes in surface composition. Two untreated disks served as controls. One-way ANOVA and Tukey's HSD post-hoc test demonstrated that air abrasion with CoJet-Sand and silane resulted in significantly higher resin-to-metal bond strength than all other metal surface treatments, while roughening with a diamond bur produced the lowest bond strength. Resin-to-metal bond strength was similar for all other particle abrasive treatments with or without silane. Using silane significantly improved bond strength only for metal surfaces treated with CoJet-Sand. An increase in Al concentration was observed on metal surfaces sandblasted with aluminum oxide, and an increase in the concentration of both A1 and Si was observed on surfaces air-abraded with CoJet-Sand. [ABSTRACT FROM AUTHOR]

The purpose of this in vitro study was to evaluate the marginal seal of two adhesive systems on class 5 composite resin restorations. Two adhesive systems that use acidic primers were used in this study: Clearfil Liner Bond 2 and Denthesive II. Scotchbond Multi-Purpose was used as a control. Class 5 cavity preparations were made at the CEJ (half of the preparation was in enamel and half in dentin/cementum) of extracted human molars. Both systems were used with and without etching. The control group was used with etching only. Composite resin restorations were placed, light cured for 40 seconds, and polished. All specimens were thermocycled 500 times. The specimens were immersed in erythrosin B, tetra-iodo-fluorescent 2% solution, then sectioned to obtain 600 ram-thick sections. These were examined under X13.2 magnification, and the degree of dye penetration was measured in microns. A chi-square test demonstrated no significant differences in microleakage among groups for either dentin (P= 0.54) or enamel (P= 0.35). [ABSTRACT FROM AUTHOR]

The purpose of this in vitro study was to compare polymerization of composite resins, as indicated by microhardness, at increasing depths using an argon laser versus a conventional light. For this, a microfill (Silux Plus) and a hybrid (TPH) composite resin were used. Five specimens per group were prepared by injecting composite into a rectangular split Teflon mold 3 x 3 x 8 mm. Specimens were then polymerized by either a 40-second exposure to the conventional visible light (VL) or a 30-, 20-, or 10-second exposure to the argon laser (AL). Specimens were stored in a light-proof container for 24 hours at 37°C, then Knoop hardness was determined. Four measurements were taken for each specimen at depths of 0, 1, 2, 3, and 4 mm from the exposed surface. No significant differences were found in surface hardness for either the microfill or hybrid composite regardless of light source or exposure time. For the microfill composite, at 1, 2, 3, and 4 mm depths, VL40 and AL30 exposures produced comparable hardness, which was significantly greater than that found for AL20 and AL10. At a depth of 4 mm, exposure to VL40 resulted in significantly greater hardness compared to AL20. With AL10 exposure, the composite was too soft to determine hardness. The hybrid composite had comparable hardness to a depth of 3 mm for VL40, AL30 and AL20. [ABSTRACT FROM AUTHOR]

The article discusses the clinical technique for the application of glass ionomer cement in the restoration of proximal root decay with the contiguous tooth. It states that in the technique, the rubber dam is advised and a floss ligature can help the isolation. Application of a thick coat of adhesive resin to the matrix is also suggested to prevent boding the glass ionomer to the matrix band. Meanwhile, the technique offers an easy approach for the restoration of difficult clinical lesions.

Objectives: The objective of this in vitro study was to compare, with a threshold value of 200 nm, the surface roughness obtained when using 12 different polishing systems on four different composite resins (microfill, nanofill, and two nanohybrids)., Methods and Materials: A total of 384 convex specimens were made using Durafill VS, Filtek Supreme Ultra, Grandio SO, and Venus Pearl. After sandblasting and finishing with a medium-grit finishing disc, initial surface roughness was measured using a surface roughness tester. Specimens were polished using 12 different polishing systems: Astropol, HiLuster Plus, D♦Fine, Diacomp, ET Illustra, Sof-Lex Wheels, Sof-Lex XT discs, Super-Snap, Enhance/Pogo, Optrapol, OneGloss and ComposiPro Brush (n=8). The final surface roughness was measured, and data were analyzed using two-way analysis of variance. Pairwise comparisons were made using protected Fisher least significant difference., Results: There were statistical differences in the final surface roughness between polishing systems and between composite resins ( p <0.05). The highest surface roughness was observed for all composite resins polished with OneGloss and ComposiPro Brush. Enhance/Pogo and Sof-Lex Wheels produced a mean surface roughness greater than the 200-nm threshold on Filtek Supreme Ultra, Grandio SO, and Venus Pearl. Data showed that there was an interaction between the composite resins and the polishing systems., Conclusions: A single polishing system does not perform equally with all composite resins. Except for Optrapol, multi-step polishing systems performed generally better than one-step systems. Excluding Enhance/Pogo, diamond-impregnated polishers led to lower surface roughness. Durafill VS, a microfill composite resin, may be polished more predictably with different polishers.

The purpose of this study was (1) to evaluate the effect of a 2-minute exposure of 5% NaOCl following acid conditioning of the dentin on the shear bond strength for two adhesive systems and (2) to examine the ultrastructure of the resindentin interface under SEM. The mesial and distal surfaces of 28 extracted human third molars were ground to expose dentin, then polished with 600-grit SiC. Teeth were randomly assigned to four test groups (n = 14) and received the following treatments: Scotchbond Multi-Purpose (SBMP)--Samples were conditioned with 37% phosphoric acid, rinsed and left moist, SBMP primer and adhesive were applied according to the manufacturer's directions, and Restorative Z-100 composite resin was bonded to the dentin surface. SBMP/NaOCl--The same procedures were followed as for SBMP except the surfaces were treated with 5% NaOCl for 2 minutes, after acid conditioning. All-Bond 2 (AB2)--The same technique was followed as for SBMP, using AB2 according to the manufacturer's recommendations. AB2/NaOCl--The same procedure was followed as for SBMP/NaOCl, using AB2. Specimens were thermocycled in a water bath 300 times between 5 degrees-55 degrees C, then sheared in a Zwick Universal Testing Machine. A one-way ANOVA and Duncan's Multiple Range Test were used for statistical analysis of the data. A 2-minute exposure of dentin to 5% NaOCl following acid conditioning of the dentin had no significant effect on the dentin shear bond strength for Scotchbond Multi-Purpose, but significantly increased the bond strength of All-Bond 2 specimens. The interfacial structure of the dentin to resin bond for two dentin treatments and two adhesive systems was studied morphologically under the scanning electron microscope. Argon ion beam etching and acid demineralization clearly revealed the hybrid layer for the conventional treatment with phosphoric acid and indicated an absence of this resin-impregnated collagen network in those specimens treated with both phosphoric acid and NaOCl.

This in vitro study determined the shear bond strengths of Tytin amalgam to dentin using All-Bond 2, Amalgambond Plus, Amalgambond Plus with HPA powder, and OptiBond with hand and mechanical (Condensaire) condensation. The occlusal enamel surfaces were ground flat to expose the dentin surfaces, and polished with 600-grit SiC paper. The dentin surfaces were treated with one of the combinations of a dentin bonding agent and a condensation technique. All specimens were thermocycled 300 cycles in water between 5-55 degrees C, and shear bond strengths were determined with a Zwick Universal Testing Machine. Two-way ANOVA and Duncan's tests showed no significant differences (P > 0.05) in shear bond strength between hand and mechanical condensation of the paired groups, with the exception of Amalgambond Plus, where hand condensation was shown to be significantly better. For both condensation techniques, shear bond strength of Amalgambond Plus with HPA powder was significantly higher than the other materials. For mechanical condensation, OptiBond was significantly higher than either Amalgambond Plus or All-Bond 2, and no significant difference was found between Amalgambond Plus and All-Bond 2. For hand condensation, OptiBond was only significantly higher than All-Bond 2, while there was no significant difference between OptiBond and Amalgambond Plus or between Amalgambond Plus and All-Bond 2. In conclusion, for both condensation techniques, Amalgambond Plus with HPA powder performed the best in bonding amalgam to dentin. The two different condensation techniques did not significantly affect shear bond strength, except with Amalgambond Plus.

Resin-modified glass ionomers, combinations of resin and glass-ionomer chemistry, have resulted in materials with longer working times and command set by visible light activation. These materials are easier to use and more resistant to early moisture contamination and fracture. A glass-ionomer or resin-modified glass-ionomer restoration may be inadvertently desiccated by isolation of the same quadrant for subsequent restorative procedures. The present study is an assessment of the effects of desiccation on microleakage of three resin-modified glass-ionomers: Vitremer, Photac-Fil, Fuji II LC; a glass-ionomer, Ketac-Fil; and a microfill resin, Silux Plus. Fifty extracted molars were prepared with class 5 preparations buccal and lingual and randomly assigned to 10 groups (n = 10). Restorations were placed according to the manufacturers' specifications and finished wet after the manufacturers' specified setting interval. All samples were thermocycled 300 cycles between 50 and 500 degrees C. Samples were stored in water at all times until the five groups to be desiccated were air dried and stored dry for 45 minutes. Desiccated groups were then rehydrated for 24 hours prior to AgNO3 staining. Teeth were sectioned mesiodistally and four buccolingual sections (0.6 mm thick) through each class 5 restoration were obtained with a Silverstone-Taylor hard tissue microtome. Each section was scored on a scale of 0-4 for microleakage, and the highest score for dye penetration was used as the score for that restoration. An increase in microleakage was observed in all desiccated groups. Three materials showed a statistically significant increase in microleakage (P < 0.05) following desiccation. Microleakage increases following a brief period of desiccation corresponding to typical treatment times indicate that clinicians need to protect previously placed restorations from undue drying during subsequent dental treatment.

The purpose of this study was to evaluate the shear bond strength of resin-modified glass-ionomer restorative materials to dentin. The materials tested were Fuji II LC, Geristore, Photac-Fil, VariGlass VLC, and Vitremer. Ketac-Fil, a conventional glass ionomer, was used as the control. The occlusal surfaces of 60 extracted molars were ground flat in dentin using 600-grit silicon carbide abrasive paper. Dentin surfaces were treated according to manufacturers' instructions, and restorative materials were applied using gelatin capsule matrices. Shear bond strengths were determined after the specimens were thermocycled 500 times. Mean bond strengths of the resin-modified glass ionomers ranged from 1.4 MPa (Photac-Fil) to 12.3 MPa (Fuji II LC). Except for Photac-Fil, all values were significantly higher than the control. Pairwise comparisons between the means for Fuji II LC and Vitremer, Vitremer and Geristore, and Geristore and VariGlass were not significantly different.

This study evaluated the shear bond strength of amalgam to dentin using five different bonding agents: Amalgambond Plus, Optibond, Imperva Dual, All-Bond 2, and Clearfil Liner Bond. Flat dentin surfaces obtained by grinding the occlusal portion of 50 human third molars were used for this study. To contain the amalgam on the tooth surface, cylindrical plastic molds were placed on the dentin and secured with sticky wax. The bonding agents were then applied according to the manufacturers' instructions or light activated and Tytin amalgam was condensed into the plastic molds. The samples were thermocycled and shear bond strengths were determined using an Instron Universal Testing Machine. Analysis by one-way ANOVA indicated significant difference between the five groups (P < 0.05). The bond strength of amalgam to dentin was significantly higher with Amalgambond Plus using the High-Performance Additive than with the other four bonding agents.