In vitro comparison of 10-minute versus 24-hour shear bond strengths of six dentin bonding systems.

OBJECTIVE: Early bond strengths produced by dentin bonding systems should be sufficient to resist the polymerization shrinkage of resin composite. This study compared the 10-minute and 24-hour shear bond strengths of six dentin bonding systems: One-Step (OS), PermaQuik (PQ), Prime & Bond 2.1 (PB), Scotchbond Multi-Purpose (SBMP), Single Bond (SB), and Tenure Quik with Fluoride (TQ). METHOD AND MATERIALS: Each bonding system was used to bond composite to visibly moist dentin at 34 degrees C +/- 2 degrees C. The specimens were debonded at 37 degrees C +/- 1 degree C 10 minutes after the start of light curing of the bonding system, and the results were compared with the 24-hour bond strengths. The mode of failure was recorded. RESULTS: The 10-minute mean shear bond strengths were: OS, 16.4; PQ, 14.3; SB, 14.0; PB, 12.7; TQ, 10.7; and SBMP, 9.3 MPa. The 24-hour mean shear bond strengths were OS, 23.3; PB, 20.8; SB, 20.3; PQ, 19.4; TQ, 11.2; and SBMP, 10.0 MPa. The 10-minute mean shear bond strengths of OS, PQ, PB, and SB bonding systems were significantly less than the 24-hour values. More dentinal fractures and mixed failures were observed with OS, PQ, and PB. Systems with higher bond strengths had more resin penetration into the lateral dentinal branches. CONCLUSION: The 10-minute mean shear bond strengths were all less than 17 MPa, and the 10-minute bond strengths were less than the 24-hour values.     

Dentin bond strengths of simplified adhesives: effect of dentin depth

The objective of this study was to compare the shear bond strength of 3 simplified adhesive systems applied on shallow vs deep dentin. For superficial dentin, 30 human molars were sectioned with a diamond saw to expose dentin immediately below the dentoenamel junction. For deep dentin, 30 molars were sectioned 3 mm below the dentoenamel junction. The teeth were mounted, polished to 600-grit, and randomly assigned to 3 groups (n=10): Single Bonda and OptiBond Solo, total-etch adhesives, and Clearfil Liner Bond 2V, a self-etching primer adhesive. Adhesives were applied, the restorative material Filtek Z250 inserted in a No. 5 gelatin capsule, and light-cured. After 24 hours in water at 37 degrees C, shear bond strength was measured with an Instron at 5 mm/min. The data were analyzed with 2-way ANOVA and Duncan's post-hoc test. The results showed the following shear bond strengths (mean +/- SD in MPa): Single Bond/superficial dentin = 22.1 +/- 2.8; Single Bond/deep dentin = 14.2 +/- 7.0; OptiBond Solo/superficial dentin = 18.9 +/- 4.1; OptiBond Solo/deep dentin = 18.4 +/- 4.8; Clearfil Liner Bond 2V/superficial dentin = 21.0 +/- 7.4; Clearfil Liner Bond 2V/deep dentin = 17.6 +/- 5.9. There were no significant differences between mean shear bond strength for the factor "adhesive system" (P>.822). The Duncan's test showed that Single Bond resulted in higher shear bond strength on superficial dentin than on deep dentin. The mean shear bond strength for Clearfil Liner Bond 2V and OptiBond Solo were not influenced by dentin depth. When data were pooled for dentin depth, deep dentin resulted in statistically lower bond strengths than superficial dentin (P<.01). The influence of dentin depth on shear bond strength depends on the specific composition of the dentin adhesive.     

Shear bond strength of "one bottle" dentin adhesives

STATEMENT OF PROBLEM: Several 1-bottle dentin adhesive resins have been introduced to the market; however, their shear bond strength still requires further investigation. PURPOSE: This study was designed to evaluate the shear bond strength of five 1-bottle fifth generation dentin adhesive resin materials. MATERIAL AND METHODS: Bond 1, Single Bond, One-Step, Prime & Bond 2.1, and Tenure Quick with fluoride were evaluated. Tenure All-Surface Bonding System, a fourth generation dentin adhesive resin, was used as the control group. Twelve specimens were prepared from each material, and the shear bond strength was measured by using a universal testing machine at a crosshead speed of 0.5 mm/min. Fracture patterns were studied with the use of light and SEM. The results were analyzed with the use of ANOVA. RESULTS: The mean shear bond strength for each resin was as follows: Bond 1: 18.36 +/- 3.19 MPa; Single Bond: 16.22 +/- 2.11 MPa; One-Step: 22.51 +/- 3.69 MPa; Prime & Bond: 16. 64 +/- 3.66 MPa; Tenure Quick: 16.43 +/- 3.2 MPa; and Tenure All-Surface Bonding System: 15.06 +/- 3.5 MPa. The shear bond strength values of One-Step dentin adhesive resin showed significant differences compared with the other 5 groups (P<.001). No significant differences were seen between the control group and the other four 1-bottle dentin adhesive resins (0.25 > P>.1). Eighty percent or more of the specimens for each adhesive failed at the dentin/adhesive interface. An exception was Tenure All-Surface Bonding System in which all specimens failed at the dentin/adhesive interface. CONCLUSION: The 1-bottle systems tested bond to dentin with a strength similar to that of the control group. In addition, the shear bond strengths of 4 of the 1-bottle systems tested were not significantly different.     

Microtensile bond strengths of seven dentin adhesive systems.

OBJECTIVES: The purpose of this study was to evaluate the microtensile bond strengths of seven dentin adhesive systems (Solid Bond, EBS-Multi, PermaQuik, One Coat Bond, Gluma One Bond, Prime & Bond NT/NRC and Clearfil Liner Bond 2V) and their respective fracture modes. METHODS: Superficial occlusal dentin of extracted human molars was exposed, finished with wet 600-grit silicon carbide paper, and a block of resin composite bonded with the above adhesives according to the manufacturers' instructions. The teeth were kept in tap water for 24 h at 37 degrees C, sectioned to obtain three or four bar-shaped specimens, which were then shaped to an hour-glass form of 1.2 +/- 0.02 mm diameter. The specimens were stressed at a crosshead speed of 1 mm/min until rupture of the bond. The mean bond strengths were compared using one-way ANOVA and LSD tests. The frequency of fracture modes was compared using Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: Mean microtensile bond strengths ranged from (17.8 +/- 7.0) MPa for Solid Bond to (36.0 +/- 8.1) MPa for Clearfil Liner Bond 2V. The bond strength of Clearfil Liner Bond 2V and PermaQuik (30.8 +/- 8.5 MPa) were not significantly different, and were higher than all other materials. Bond strengths of Solid Bond (17.8 +/- 7.0) MPa, EBS-Multi (18.7 +/- 5.0) MPa, One Coat Bond (21.9 +/- 5.6) MPa, and Gluma One Bond (23.4 +/- 5.2) MPa were not significantly different. SEM examination indicated that Solid Bond, EBS-Multi and One Coat Bond showed no significant difference in failure modes but were significantly different from PermaQuik, Prime & Bond NT/NRC and Clearfil Liner Bond 2V. SIGNIFICANCE: The self-etching primer system, Clearfil Liner Bond 2V, provided the simplest bonding technique, and together with PermaQuik exhibited greatest bond strength to dentin.     

Bonding to enamel and dentin using self-etching adhesive systems.

OBJECTIVES: This study investigated the effectiveness of three different dentin adhesive systems on the adhesion of resin composite to both dentin and enamel. METHOD AND MATERIALS: The flat dentin and enamel surfaces of 60 extracted human molar teeth were exposed by wet grinding with 600-grit silicon carbide paper. One total-etch self-priming adhesive system (Prime & Bond NT), one two-step self-etching primer adhesive system (Clearfil SE Bond), and one "all-in-one" self-etching adhesive system (Prompt L-Pop) were evaluated. Each bonding system was applied according to the manufacturer's instructions and followed by composite (TPH Spectrum) application. Twenty-four hours after bonding, the teeth were subjected to shear testing. There were 10 replicates for each group. RESULTS: Prompt L-Pop exhibited significantly higher bond strength values to enamel (27 +/- 4.2 MPa) than all other groups. There were no statistically significant differences for shear bond strength to dentin among adhesives. Prompt L-Pop showed the statistically significantly higher bond strength to enamel than dentin. There were no statistically significant differences between the enamel and dentin bond strengths of Clearfil SE Bond and Prime & Bond NT. CONCLUSIONS: The self-etching adhesive systems produced high bond strengths to human coronal dentin and ground enamel surfaces. These materials seem to be very promising for further clinical applications, and the results are very encouraging for the clinical success of these simplified adhesive systems. The self-etching adhesive systems produced even better bond strengths to both enamel and dentin than conventional total-etch systems, especially the "all-in-one" system, which produced the highest bond strength to enamel.     

Effect of an antibacterial adhesive on the bond strength of three different luting resin composites

OBJECTIVES: Effect of a dentin adhesive system containing antibacterial monomer-MDPB (Clearfil Protect Bond) on the shear bond strength of all-ceramic-IPS Empress 2 restorations luted with three different dual-polymerizing systems (Variolink 2, RelyX ARC and Panavia F 2.0) to dentin was investigated. METHODS: One hundred and eight all-ceramic discs (2 x 3mm; IPS Empress 2) were fabricated and ultrasonically cleaned. The buccal surfaces of 108 non-carious extracted human premolars were flattened to expose dentin and subsequently polished with 600-grit wet silicon carbide paper. Three dual-polymerizing luting systems had test groups and control groups consisting of 18 samples each. For the test groups Clearfil Protect Bond was applied to the exposed dentin surfaces. Control groups received the original bonding procedures of each adhesive system. After the all-ceramic samples were luted to the teeth, thermocycling was performed 5000 times. Shear bond strengths were tested using Shimadzu Universal Testing Machine until failure. Analysis of fractured dentin surfaces were performed using Optical Microscope at x10 and x1000 magnifications and the images were analyzed with Image Analyzer. Data was analyzed with one-way ANOVA and Bonferroni test at a significance level of p<0.05. RESULTS: Mean shear bond strength data of the groups in MPa were; Variolink: 20.45+/-4.75, Variolink+Clearfil Protect Bond:29.32+/-2.37, RelyX ARC:18.82+/-3.19, RelyX ARC+Clearfil Protect Bond:25.58+/-4.05, Panavia F 2.0:17.11+/-2.98, Panavia F 2.0+Clearfil Protect Bond:24.40+/-7.46. Application of the antibacterial adhesive increased the shear bond strengths of all three dual-polymerizing systems to dentin (p=0.00). The surface analysis showed that most of the specimens showed the adhesive failure mode between the dentin and the composite luting agent interface. CONCLUSION: The antibacterial adhesive system Clearfil Protect Bond can be safely used to prevent the potential risk of complications resulting from bacterial activity regardless of affecting the bond strength of IPS Empress 2 restorations luted with the dual-polimerizing systems used in this study.     

Shear bond strengths of resin adhesive cements to dentin and Ni-Cr-Be alloy.

Two adhesives, Super Bond and Panavia, were evaluated for shear bond strength to dentin. Twenty human teeth were used for each adhesive. Bonding sites were prepared in dentin (600 grit) and the adhesives applied according to the manufacturers' instructions. Bond strengths were determined with an Instron testing machine at 24 hours. Super Bond developed the strongest bond of 21.59 +/- 3.91 MPa. Panavia produced a lower bond strength of 2.68 +/- 1.45 MPa. Statistically, Super Bond was found to have a stronger bond than Panavia. The same two adhesives were applied to Ni-Cr-Be specimens and compared to Comspan. Twenty Rexillium III specimens were used for each adhesive at 24 hours and 20 for thermocycling. The metal specimens were ground flat (600 grit) and then air abraded with 50-micron aluminous oxide. The adhesives were applied to the metal surface in accordance with the manufacturers' instructions. One group was tested at 24 hours while the second group was tested after thermocycling (2,500 cycles at 6 degrees C to 60 degrees C). At 24 hours, Super Bond had a significantly stronger bond than the other materials. Comparison of the 24-hour to thermocycled bond strengths found Comspan had a significant increase in bond strength, Panavia had no significant change and Super Bond had a significant decrease in bond strength. After 2,500 thermocycles, Comspan, Panavia, and Super Bond were not significantly different in bond strength.     

Bonding efficacy of single-step self-etch systems to sound primary and permanent tooth dentin

Currently, there is little information regarding the bonding efficacy of single-step self-etch systems to primary tooth dentin. This study examined the microtensile bond strength of single-step self-etch systems (Clearfil tri-S Bond and One-Up Bond F Plus) to sound primary and permanent tooth dentin. Adhesives were applied to flat samples of primary and permanent tooth dentin, and resin composites were bonded according to the manufacturers' instructions. After 24 hours of storage in distilled water at 37 degrees C, hour glass-shaped specimens were produced. They were subjected to microtensile testing at a crosshead speed of 1.0 mm/minute. The results were analyzed using 2-way analysis of variance (ANOVA) followed by the Tukey HSD post-hoc test (alpha=0.05). Field-emission scanning electron microscopy (FE-SEM) observations of the adhesive-treated dentin surfaces and the resin/dentin interface were also conducted. The bond strengths of primary tooth dentin were significantly lower than that of permanent tooth dentin for both self-etch systems: 44.7 +/- 10.4 versus 54.3 +/- 9.0 MPa for Clearfil tri-S Bond and 40.6 +/- 9.9 versus 50.0 +/- 8.7 MPa for One-Up Bond F Plus (p<0.001). There was no statistically significant interaction between the type of adhesive system and the dentin substrate (p=0.957). Although there was no statistically significant difference in the mean values among the different adhesive systems (p=0.094), there was a statistically significant difference in mean values among the different dentin substrates (p<0.001), which were lower for primary tooth dentin than for permanent tooth dentin. The failure modes were also independent of the type of dentin but dependent on the adhesive systems, an equal distribution among the 3 types of failure for Clearfil tri-S Bond and cohesive failures in adhesives for One-Up Bond F Plus. FE-SEM observations of dentin to which adhesive had been applied revealed that the smear layer had been removed and the collagen fibers exposed. Though the bond strengths to primary tooth dentin were lower than to permanent tooth dentin, excellent adaptation of the single-step self-etch systems to both dentin substrates was observed by FE-SEM. Further studies are required to determine the long-term clinical performance of these adhesive systems when applied to primary tooth dentin.     

Microtensile testing of dentin adhesives.

OBJECTIVES: This study was conducted in order to compare the microtensile and shear bond strengths of five commercial dentin adhesive systems. Scotchbond Multipurpose with maleic acid (SM), Scotchbond Multipurpose with phosphoric acid (SP), Scotchbond Multipurpose Plus (SBP), Clearfil Liner Bond System (CL), and Prime and Bond (PB) were tested. METHODS: Thirty extracted unerupted third molars, in groups of six teeth per adhesive system, were prepared for microtensile testing. The specimens were tested following a 24 h incubation at 37 degrees C in normal saline. Shear bond testing was performed on 35 additional teeth, using seven teeth per adhesive system. After testing, the fracture sites were observed using light microscopy and a scanning electron microscope to determine the type of failure involved. RESULTS: The microtensile test results (mean +/- SD) were SM, 24.6 +/- 7.2 MPa; SP, 28.8 +/- 11.8 MPa; SBP, 22.7 +/- 6.5 MPa; PB, 25.5 +/- 9.4 MPa; and CL, 36.8 +/- 10.0 MPa. A Bonferroni post-hoc test showed significantly (p < 0.05) greater strength for CL compared to SM, SP, SBP, and PB. The shear bond strength test results were SM, 19.4 +/- 4.4 MPa; SP, 24.5 +/- 8.4 MPa; SBP, 15.3 +/- 4.9 MPa; PB, 23.2 +/- 7.1 MPa; and CL, 24.8 +/- 3.5 MPa. No statistically significant differences were found among the shear bond strength test results. The shear bond test produced significantly more failures within dentin and composite than the microtensile method. SIGNIFICANCE: It is concluded that the microtensile test produced a more definitive assessment of adhesive bond strength than the shear bond test. Microtensile testing showed CL to be significantly stronger than SM, SP, SBP, and PB (p < 0.05).     

Influence of delayed placement of composites over cured adhesives on dentin bond strength of single-application self-etch systems

This study examined the relationship between delay in composite placement over cured adhesives and the dentin bond strength of several single-application self-etch adhesive systems. The adhesive system/resin composite combinations used were: Adper Prompt L-Pop/Filtek Z250 (AP), AQ Bond Plus/Metafil C (AQ), Fluoro Bond Shake One/Beautifil (FB), G-Bond/Solare (GB), One-Up Bond F Plus/Palfique Estelite (OF), Xeno IICF Bond/Xeno CF (XE). Bovine mandibular incisors were mounted in self-curing resin and wet ground with #600 SiC to expose labial dentin. The adhesives were applied according to each manufacturer's instructions, and resin pastes were condensed into a mold (?4x2 mm) immediately, and 1, 2, 5 and 10 minutes after light irradiation of the adhesives. Ten samples per test group were stored in 37 degrees C water for 24 hours, then shear tested at a crosshead speed of 1.0 mm/minute. One-way ANOVA followed by Tukey's HSD test (alpha = 0.05) was done. SEM observations of the dentin surface after the tests were also conducted. Dentin bond strength ranged from 9.5 +/- 2.2 to 14.0 +/- 2.4 MPa for AP, 7.3 +/- 2.2 to 12.2 +/- 3.1 MPa for AQ, 10.0 +/- 3.5 to 16.3 +/- 2.4 MPa for FB, 11.4 +/- 1.5 to 16.3 +/- 1.2 MPa for GB, 14.2 +/- 3.4 to 15.1 +/- 3.0 MPa for OF and 11.5 +/- 2.4 to 15.9 +/- 2.2 MPa for XE. Except for OF, no significant differences were found among the 2 to 10 minute delayed placement groups for the systems used. Significant lower bond strengths were obtained for the immediate placement groups except for OF. From SEM observations, cohesive failure of the dentin surface was more pronounced with the longer delay in placement. The data suggest that delayed composite placement over the cured adhesives are suggested for optimum dentin bond strength of single-application self-etch adhesive systems.     

Effect of air-drying time of single-application self-etch adhesives on dentin bond strength

This study examined the effect of air-drying time of adhesives on the dentin bond strength of several single-application self-etch adhesive systems. The adhesive/resin composite combinations used were: Adper Prompt L-Pop/Filtek Z250 (AP), Clearfil Tri-S Bond/Clearfil AP-X (CT), Fluoro Bond Shake One/Beautifil (FB), G-Bond/Gradia Direct (GB) and One-Up Bond F Plus/Palfique Estelite (OF). Bovine mandibular incisors were mounted in self-curing resin and wet ground with #600 SiC to expose labial dentin. Adhesives were applied according to each manufacturer's instructions followed by air-drying time for 0 (without air-drying), 5 and 10 seconds. After light irradiation of the adhesives, the resin composites were condensed into a mold (phi4x2 mm) and polymerized. Ten samples per test group were stored in 37 degrees C distilled water for 24 hours; they were then shear tested at a crosshead speed of 1.0 mm/minute. One-way ANOVA followed by Tukey's HSD tests (alpha = 0.05) were done. FE-SEM observations of the resin/dentin interface were also conducted. Dentin bond strength varied with the different air drying times and ranged from 5.8 +/- 2.4 to 13.9 +/- 2.8 MPa for AP, 4.9 +/- 1.5 to 17.1 +/- 2.3 MPa for CT, 7.9 +/- 2.8 to 13.8 +/- 2.4 MPa for FB, 3.7 +/- 1.4 to 13.4 +/- 1.2 MPa for GB and 4.6 +/- 2.1 to 13.7 +/- 2.6 MPa for OF. With longer air drying of adhesives, no significant changes in bond strengths were found for the systems used except for OF. Significantly lower bond strengths were obtained for the 10-second air-drying group for OF. From FE-SEM observations, gaps between the cured adhesive and resin composites were observed for the specimens without the air drying of adhesives except for OF. The data suggests that, with four of the single-application self-etch adhesive systems, air drying is essential to obtain adequate dentin bond strengths, but increased drying time does not significantly influence bond strength. For the other system studied, the bond strength of the non-air dried group was not significantly different from the five second drying time, but prolonged drying was very detrimental to bond strength. For all five of the systems studied, a five-second air-drying time appeared to be appropriate.     

Laboratory evaluation and clinical application of a new one-bottle adhesive.

PURPOSE: The purposes of this project were to compare the enamel and dentin bond strengths of a new nanofilled one-coat adhesive system with its predecessor, an unfilled two-coat adhesive system; to analyze the dentin interfacial ultramorphology, using scanning and transmission electron microscopy (SEM and TEM); and to illustrate the clinical technique associated with the use of the new nanofilled one-coat adhesive system. MATERIAL AND METHODS: Twenty flat dentin surfaces and 20 flat enamel surfaces were polished on the labial surface of bovine incisors mounted in acrylic resin. The specimens were equally and randomly assigned to four bonding groups: (1) dentin with Prime & Bond 2.1; (2) dentin with Prime & Bond NT; (3) enamel with Prime & Bond 2.1; and (4) enamel with Prime & Bond NT. A composite post was then adapted to the treated area and light-cured. After thermocycling, shear bond strengths were determined by testing the shear strength of the specimens. The data were analyzed using one-way analysis of variance (ANOVA) and Student's t-test. For SEM and TEM, six dentin disks were obtained from middle dentin of human third molars and assigned equally to each adhesive. The adhesives were applied to dentin according to manufacturer's directions. The hybrid layer and resin penetration into dentin tubules were analyzed at an ultramorphologic level, and the observations were compared. RESULTS: Shear bond strengths were as follows: group 1: 17.8 +/- 4.1 MPa; group 2: 20.5 +/- 3.5 MPa; group 3: 24.7 +/- 6.7 MPa; and group 4; 27.0 +/- 5.4 MPa. Electron microscopy showed that both adhesives penetrated the dentin tubules and formed a fully infiltrated hybrid layer. The nanofiller included in the new one-application adhesive penetrated the dentin tubules and infiltrated the microspaces between the collagen fibers within the hybrid layer. CLINICAL SIGNIFICANCE: The new one-application nanofilled adhesive tested in this study resulted in bond strengths and dentin hybridization comparable to those obtained with the corresponding two-application system. The clinical sequences presented illustrate the ease of use of the newest simplified adhesives.     

Effect of dentin primer on shear bond strength of composite resin to moist and dry enamel

The etched enamel-composite resin bond is the most reliable bond known to us. Moisture and dentin primers are the two most important variables that can interfere with this bond. This study investigated the effect of dentin primer on bond strengths of composite resin to moist and dry enamel. One hundred freshly extracted molar teeth were used for shear bond strength testing. The teeth were mounted in phenolic rings with an approximal enamel surface exposed. The exposed enamel surface on each tooth was flattened using 320- 400- and 600-grit silicon carbide papers and etched using 34-38% phosphoric acid gel. The teeth were then divided into 10 groups (n = 10). Four groups were assigned to each of the two dentin bonding systems, Scotchbond Multi-Purpose and OptiBond FL. Two groups were assigned to the single-bottle bonding agent (Single Bond). Each bonding system was tested on moist and dry enamel. OptiBond FL and Scotchbond MP were tested with and without the use of primer. All samples were thermocycled and tested in shear. Fracture analysis was performed using a binocular microscope. For scanning electron microscopy, approximal samples of enamel (1 mm thick) were flattened, etched, and bonded with and without primer on moist and dry enamel. A 1 mm-thick layer of Z100 was bonded to the specimens, which were then immersed in 10% HCl for 24 hours to dissolve the enamel. The specimens were viewed under a scanning electron microscope. Results indicated that the use of primer on dry enamel did not significantly affect (P > 0.05) shear bond strengths for the two bonding systems, Scotchbond MP (primed 24.10 +/- 4.83 MPa, unprimed 29.57 +/- 7.49 MPa) and OptiBond FL (primed 26.82 +/- 4.44, unprimed 25.66 +/- 2.95). However, the use of primer was found to be essential on moist enamel to obtain acceptable bond strengths with both Scotchbond MP (primed 25.61 +/- 10.29 MPa, unprimed 3.26 +/- 0.95 MPa) and OptiBond FL (primed 30.28 +/- 3.49 MPa, unprimed 8.37 +/- 3.31 MPa). Moisture on enamel did not significantly affect (P > 0.05) bond strengths for the single-bottle bonding agent, Single Bond (moist enamel 31.34 +/- 9.03 MPa, dry enamel 27.93 +/- 5.41 MPa). Fracture analysis revealed that most fractures were adhesive or mixed, with a greater percentage being cohesive for the groups with dry enamel or with primer on moist enamel. Scanning electron micrographs corroborated the shear bond strength data. The specimens without primer on moist enamel showed very poor penetration of adhesive and composite resin into the etched enamel microporosities.     

Influence of storage conditions of adhesive vials on dentin bond strength

This study was carried out to examine the effect of storage conditions of adhesive vials on the dentin bond strength of single-step self-etch adhesive systems. The adhesive/resin composite combinations used were: Absolute 2/Ceram.X(AB), Adper Prompt L-Pop/Filtek Supreme(AP), Bond Force/Estelite sigma Quick(BF), Clearfil tri-S Bond/Clearfil AP-X(CT) and G-Bond/Gradia Direct(GB). Vials of adhesives were stored at 5 degrees C, 23 degrees C or 40 degrees C. Specimens for the dentin bond strength tests were made after 0, 1, 2, 3, 4, 5 and 6 months. Labial bovine mandibular incisor dentin was wet ground with #600 SiC. The adhesives were applied according to the manufacturer's instructions. After adhesive light irradiation, resin composite cylinders were created (4 mm x 2 mm) and polymerized (n = 10). Samples were stored in 37 degrees C distilled water for 24 hours, then shear tested at a crosshead speed of 1.0 mm/minute. ANOVA and Dunnet tests were performed at a significance level of 0.05. Scanning electron microscopic (SEM) observations of the dentin surfaces were made. Bond strengths varied, with storage conditions ranging from 2.2 +/- 1.4 to 9.3 +/- 2.4 MPa for AB, 4.5 +/- 1.5 to 13.3 +/- 2.7 MPa for AP, 5.1 +/- 1.9 to 5.1 +/- 1.9 MPa for BF, 7.7 +/- 1.9 to 19.7 +/- 2.0 MPa for CT and 7.4 +/- 1.3 to 15.7 +/- 2.8 MPa for GB. With longer storage periods and higher temperatures, significant decreases in bond strength were found for all the adhesives. From SEM observation, the etching effect of the adhesives was weakened and the remaining smear layer was observed. The data suggests that the storage conditions of adhesive vials significantly affects the bond strengths of single-application self-etch adhesive systems.     

Dentin shear bond strength of compomers and composites.

OBJECTIVE: The aim of this study was to compare the shear bond strengths and fracture characteristics of two compomers bonded with a single step bonding agent with two modern composites, a microfil and hybrid, bonded with a fourth generation bonding agent. METHODS: Freshly extracted human third molars were sectioned parallel to the occlusal surface to expose midcoronal dentin, prepared with 320-grit surface finish, and bonded (N = 11 samples/group) following manufacturer's directions with the compomers (Dyract, DeTrey Konstanz, Germany or Compoglass, Vivadent, Schaan Liechtenstein) or the dentin bonding agent SMP+ (Scotchbond Multi-Purpose Plus, 3M Dental Products, St. Paul MN) with Silux Plus or Z100 (3M Dental Products, St. Paul, MN). The samples were tested using a single plane lap shear bond strength test at 5 mm/min until failure. Statistical analysis was performed using ANOVA with Scheffe multiple comparison testing. Fracture surfaces of the debonded surfaces were examined using SEM to determine the failure mode of each specimen. RESULTS: Bond strengths for the compomers were 12.7 +/- 2.9 MPa for Dyract and 8.9 +/- 4.1 MPa for Compoglass and were not significantly different. Bond strengths for the dentin bonded composites were significantly stronger than the compomer Compoglass, but were not different from one another, despite the use of different composites. The averages values for SMP + /Silux Plus and SMP + /Z100 were 15.7 +/- 4.5 MPa and 15.2 +/- 5.6 MPa, respectively. SEM analysis showed that all materials exhibited mixed failure patterns. Compoglass specimens exhibited 5 of 11 failures classified as adhesive, while each of the other materials showed only 1 of 11 adhesive failures. SIGNIFICANCE: Compomers have undergone rapid development over the last several years, but their bond strengths have not yet reached the same level as modern dentin bonded composites. Difference in composite filler type and amount had little influence on the bond strength determined in this work.     

Effect of priming time on tensile bond strength to bovine teeth and morphologic structure of interfaces created by self-etching primers

PURPOSE: The purpose of this study was to investigate the effect of priming time on bovine enamel and dentin adhesion promoted by self-etching primer systems. MATERIALS AND METHODS: Two commercial self-etching primer systems, Clearfil SE Bond (SE) and Unifil Bond (UB), were used. Bovine enamel and dentin were treated with each system with various priming times (5, 20, and 60 seconds), and the tensile bond strength was measured. Scanning electron microscopic (SEM) observation was also performed to examine the effect of priming time on the morphology of the resin-tooth interface. RESULTS: The tensile bond strength to enamel ranged from 10.6 to 14.3 MPa, and no statistically significant difference was detected among products or priming times. To dentin, UB showed the statistically significantly lowest tensile bond strength when primed for 5 seconds, 6.9 +/- 1.1 MPa, but there was no significant difference between the groups primed for 20 and 60 seconds, 13.5 +/- 4.1 MPa and 13.8 +/- 4.6 MPa, respectively. SE created tensile bond strengths ranging from 13.9 to 15.7 MPa and showed no effect of priming time on dentin adhesion. SEM observation revealed that resin penetrated into both enamel and dentin more deeply with extension of priming time. CONCLUSION: Priming times longer than those recommended by the manufacturers did not influence the tensile bond strength to enamel and dentin when using two commercial self-etching primers. In contrast, a shortened priming time, 5 seconds, carried a risk of decreasing dentin adhesion, although it had no adverse effect on enamel adhesion.     

Bond strength of composite to dentin using conventional, one-step, and self-etching adhesive systems

OBJECTIVES: This in vitro study compared the dentin bonding performance of eight adhesive systems using a microtensile bond strength test. METHODS: Thirty bovine teeth were ground to 600-grit to obtain flat root-dentin surfaces. Two conventional adhesive systems (Scotchbond Multipurpose Plus, OptiBond FL), four one-step adhesive systems (Scotchbond 1, Asba S.A.C., Prime and Bond NT, Excite) and two self-etching adhesive materials (Clearfil Liner Bond 2 V and Prompt L-Pop) were evaluated. Each bonding system was applied according to manufacturer's instructions and followed by composite (Z100) application. Immediately after bonding, the teeth were prepared for microtensile testing. Bond strength to dentin was measured using a Vitrodyne V-1000 universal tester. There were 14 replicates for each material. Fractured specimens were further observed by SEM. RESULTS: Scotchbond Multipurpose Plus exhibited significantly (p<0.05) higher bond strength values (30.3+/-9.4 MPa) than all other materials. The bond strengths of the other materials were (from highest to lowest): Opitbond FL (22.4+/-4.3 MPa); Scotchbond 1(18.9+/-3.2); Clearfil Liner Bond 2 V (18.9+/-3.0); Prime and Bond NT (18.3+/-6.9); Asba S.A.C. (14.4+/-2.9); Excite (13.8+/-3.7); and Prompt L-Pop (9.1+/-3.3). Statistical comparisons frequently overlapped, but Optibond was significantly (p<0.05) greater than Asba, Excite, and Prompt L-Pop; whereas, Scotchbond 1 was only significantly (p<0.05) greater than Prompt L-Pop. Asba, Excite and Prompt L-Pop were not significantly different. The fracture modes were mostly adhesive. CONCLUSIONS: The conventional adhesive systems produced higher bond strengths to root dentin than most one-step adhesives and one self-etching adhesive; with the exception of one material in each respective system.     

Effects of adhesive liner and provisional cement on the bond strength of nickel/chrome/beryllium alloy cemented to dentin.

OBJECTIVE: Treating teeth with adhesive agents before placing a provisional restoration can prevent tooth sensitivity. This study evaluated the bond strength of resin cements to dentin treated with 2 adhesive agents and 2 provisional cements. METHODS AND MATERIALS: Extracted human molars were prepared by exposing dentin and were treated with either Prime & Bond NT or Clearfil SE Bond. After a simulated impression technique, the teeth were provisionalized with either a eugenol or noneugenol temporary cement. Teeth were cleaned for bonding by either mechanical removal of the cement or use of an acid conditioner. Panavia F and Calibra resin cements were used to cement nickel/chrome/beryllium alloy to the tooth surfaces, and the specimens were debonded. Mean shear bond strengths for each group were calculated. RESULTS: Mean shear bond strengths ranged from 26.6 +/- 5.8 MPa for Calibra bonded to dentin treated with Prime & Bond NT, a noneugenol cement, and mechanically cleaned, to 10.6 +/- 4.4 MPa for Panavia F bonded to unlined (no adhesive) dentin treated with a eugenol cement and mechanically cleaned. Of the 14 groups tested, significant differences were observed related to the adhesives and resin cements. Both temporary cements reduced the bond to dentin not treated with a resin adhesive. Use of an acid conditioner for cleaning the temporary cement also reduced bond strengths in all groups. CONCLUSIONS: Placement of a dentin adhesive before provisionalization may prevent the temporary cement from affecting the bond of the final resin cement to the tooth. For the products used in this study, use of phosphoric acid to clean the tooth surface is not recommended.     

A comparison of microtensile bond strengths of several dentin bonding systems to primary and permanent dentin.

OBJECTIVES: Limited information exists with regard to the adhesive ability of glass ionomer cements (GIC) and recently developed resin-based dentin bond systems to primary dentin. The aim of this study was to compare the microtensile bond strength of a conventional GIC (Fuji IX), a resin-modified GIC (Fuji II LC), and two resin-based dentin adhesives (Prime and Bond NT with NRC and Single Bond). The bonded interfaces were also observed using field emission electron microscopy(FE-SEM). METHODS: Microtensile bond test specimens were prepared on superficial dentin of primary and permanent molars. The specimens were bonded according to each manufacturer's instructions except for Prime and Bond NT/NRC which used Silux Plus resin composite instead of Dyract. Hour-glass shaped specimens were created (diameter of 1.2+/-0.02 mm) and stressed in tension at a crosshead speed of 1mm/min. Results were analyzed using two-way ANOVA and LSD test, fracture modes were analyzed using the Mann-Whitney U-test and Kruskall-Wallis test. Twelve specimens were prepared for each material on primary and permanent dentin. Samples were prepared in the same manner, then critical point dried, fractured and sputter-coated for the FE-SEM observations. RESULTS: Two-way ANOVA showed the overall bond strengths were greater for the permanent dentin compared with primary dentin. However, for individual material comparisons no differences among the bond strengths to primary and permanent dentin for Fuji IX (9.7, 12.2 MPa), Fuji II LC (16, 20.1 MPa), Prime & Bond NT/NRC (18.1, 21.6 MPa) and Single Bond (18.2, 21.6 MPa), were detected. However, Fuji IX bond strengths were significantly lower than the other systems tested when bonded to either primary or permanent dentin (p<0.05). Failure mode showed cohesive failure of GIC and mostly adhesive failure for the resin-based adhesives. The FE-SEM observations showed hybrid-like layer formation for the GIC materials and hybrid layer formation for the resin-based adhesives. SIGNIFICANCE: The materials tested would be suitable for bonding to either primary or permanent dentin, but the resin-modified GIC or resin-based systems are likely to provide a stronger bond than the conventional GIC, Fuji IX.     

一步法自酸蚀粘接剂微拉伸粘接强度的研究

目的评价一步法白酸蚀粘接剂的牙本质微拉伸粘接强度，观察并分析样本断裂类型。方法选择新拔除的人无龋下颌第三磨牙12颗，分别用3种一步法、1种两步法的白酸蚀粘接剂进行牙本质粘接。用微拉伸测力仪测试粘接强度，并用体视显微镜和扫描电镜观察样本断裂类型。结果3种一步法白酸蚀粘接剂的微拉伸强度分别为：材料A（Adper Prompt）（23．36±2．55）MPa；材料B（Clearfil S^3 Bond）（30．46±3．82）MPa；材料C（Xenon Ⅲ）（34．59±3．46）MPa；1种两步法自酸蚀粘接剂材料D（Clearfil SE Bond）的微拉伸粘接强度为（45．06±5．29）MPa。材料D微拉伸粘接强度最高，与其他3组相比，差异具有统计学意义（P〈0．01）。样本断裂均发生于粘接界面，未观察到复合树脂或牙本质内聚破坏。结论一步法白酸蚀粘接剂的牙本质粘接强度低于两步法白酸蚀粘接剂，但多数仍可满足临床对树脂粘接强度的要求。