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Micro-shear bond strength of five resin-based composites to dentin with five different dentin adhesives.

PURPOSE: To test whether the combination of dentin adhesive and resin-based composite from the same manufacturer had higher micro-shear bond strength than the other combinations of different manufacturers. METHODS: 25 experimental micro-shear bond test groups were made from the combination of five resin-based composites and five dentin adhesives (three total-etch adhesives and two self-etch adhesives) with extracted human molars stored in saline for 24 hours. The test was performed with the wire-loop method using a universal testing machine, and the micro-shear bond strengths were calculated. SEM photomicrographs of fractured sites were taken to check the failure mode. RESULTS: The combinations from same manufacturers failed to show higher bond strengths than the other combinations. Self-etch adhesives showed significantly higher micro-shear bond strengths than total-etch adhesives (P < 0.05). In total-etch adhesives, the kind of resin composite was important and in self-etch adhesives, the kind of adhesive had significant effect on micro-shear bond strength (P < 0.05). All sites showed mixed fractures.

Acrylic Resins↗

In vitro dentin pretreatment: surface roughness and adhesive shear bond strength.

The aim was to define the morphology and roughness of dentin from different tooth areas after various pretreatments to identify the effect of hybrid layer, resin tags, and mineralised dentin surface on shear bond strength. Thirty-eight extracted molars were used, each providing two sections of cervical (c) and lateral (l) dentin. Five pretreatments were performed: A) 0.2% EDTA; B) abrasion with Al2O3 particles, 0.2% EDTA; C) 10% H3PO4; D) 10% H3PO4 and immersion in a collagenase solution; E) control: no treatment. Z100 composite resin cylinders were bonded to the specimens with All Bond 2 bonding resin and tested for shear bond strength. Twelve other specimens from each group were analysed with an optical profilometer and an atomic force microscope, and four were further examined by scanning electron microscopy (SEM). Mean shear strength values in MPa were: Ac: 8.36 +/- 4.23; Al: 8.77 +/- 3.68; Bc: 6.05 +/- 3.62; Bl: 8.39 +/- 4.60; Cc: 6.87 +/- 3.45; Cl: 9.00 +/- 5.62; Dc: 13.30 +/- 5.45; Dl: 8.44 +/- 4.47; Ec: 4.10 +/- 1.54; El: 6.09 +/- 4.34. No statistically significant difference for cervical versus lateral dentin was found within treatments except for group D. Treatments performed on lateral dentin did not differ significantly. In cervical dentin, A differed from E; C from E; and D from A, B, C and E. An increased surface roughness was found in group D. Shear bond strength to dentin did not seem to depend on a hybrid layer formation, but on the direct contact of the adhesive with the mineralised dentinal surface and partly on the orientation of the dentinal tubules.

Acid Etching, Dental↗

Shear bond strength of four filled dentin bonding systems.

This study compared the shear bond strength of four filled dentin bonding agents (Prime & Bond NT, One Coat Bond, OptiBond Solo, PermaQuik1) to a conventional unfilled Dentin Bonding agent (3M Scotchbond Multipurpose Plus). A column of composite resin (Herculite XRV Restorative Resin) was bonded to human dentin using the five dentin-bonding systems following the manufacturers' directions. The specimens were thermocycled 1000 cycles from 6 to 60 degrees C. Each specimen was tested on an MTS machine in shear-to-failure. The data were subjected to One-Factor ANOVA and Newman-Kuels post-hoc tests. Statistical analysis revealed that One Coat Bond had significantly greater shear bond strength than all other materials tested.

Analysis of Variance↗

A comparison of the shear bond strengths of two glass ionomer cements.

The objective of this study was to determine the in vitro shear bond strength (in megapascals) and location of bond failure with two light-cured glass ionomer resin systems. One system was a hybrid glass ionomer cement with resin (GC Orthodontics, Aslip, Ill), and the other system a glass-filled resin system (Reliance Orthodontic Products, Inc, Itasca, Ill). These systems, Fuji Ortho LC (GC Orthodontics) and Ultra Band Lok (Reliance), respectively, were compared to a light-cured composite resin. Maxillary premolar brackets (n = 200) were bonded to the facial surface of human premolar teeth. The two glass ionomer resin systems were each evaluated by two protocols, one according to the manufacturers' direction plus a variation of their respective technique. The five distinct groups (n = 40) were stored in 37 degreesC distilled water for 30 days and subjected to thermocycling before shear bond strength testing. The findings indicated that large variations existed between the bond strengths of the materials tested. The laboratory shear bond strength of the glass-filled resin glass ionomer cement (Reliance), whether tested in a dry or moist field, was similar to the composite control with all of the previous materials being significantly (P <.01) higher than both the hybrid glass ionomer cement groups (Fuji Ortho LC). However, the hybrid glass ionomer cement with enamel conditioner demonstrated a clinically acceptable mean megapascal value. The Adhesive Remnant Index values ranged from 0.53 to 1.62. The hybrid glass ionomer cement without enamel conditioning recorded the lowest mean adhesive remnant index score and the lowest mean megapascal score. Although both products are glass ionomer resin systems, their individual chemistries vary; this affects their clinical performance. Clinically, it may be suggested that glass ionomers used in a dry field may be beneficial for orthodontic bonding, and that glass ionomer resin systems used in a moist environment need an enamel conditioner.

Acrylic Resins↗

Shear bond strength of hydrophilic adhesive systems to enamel.

PURPOSE: To compare the enamel shear bond strength of four hydrophilic adhesive systems: one multiple-bottle (Scotchbond Multi-Purpose Plus), two one-bottle (Stae, Single Bond) and one self-etching (Etch & Prime). MATERIALS AND METHODS: 120 bovine incisor teeth were obtained, embedded in polyester resin, polished to 600 grit to form standardized enamel surfaces, and randomly assigned to four groups (n = 30). Each adhesive system was used on enamel according to the manufacturer's instructions, and resin-based composite (Z100) cylinders with 3 mm diameter and 5 mm height were bonded. Specimens were stored in humid environment for 1 week, and bond strength was determined using a universal testing machine, at a crosshead speed of 0.5 mm/minute. RESULTS: The mean shear bond strength values (MPa +/- SD) were: Single Bond: 24.28 +/- 5.27 (a); Scotchbond Multi-Purpose Plus: 21.18 +/- 4.35 (ab); Stae: 19.56 +/- 4.71 (b); Etch & Prime 3.0: 15.13 +/- 4.92 (c). ANOVA revealed significant difference in means (P < 0.01) and Tukey's test showed the statistical differences that are expressed by different letters for each group. It could be concluded that the self-etching adhesive system did not provide as good a bond to enamel surface, as did the one- and multiple-bottle systems.

Animals↗

Amalgam shear bond strength to dentin using different bonding agents.

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.

Composite Resins↗

Shear bond strength of orthodontic brackets with 3 self-etch adhesives.

INTRODUCTION: The purpose of this study was to compare shear bond strength and mode of failure of brackets bonded with 3 self-etching products. METHODS: The products tested were (1) a recently developed, modified self-etching, 1-step adhesive system (Adper Prompt L-Pop Self Etch Adhesive, 3M, St Paul, Minn); (2) a new fluoride-releasing, antibacterial, self-etching adhesive system (Clearfil Protect Bond, Kuraray, Osaka, Japan); and (3) a fluoride-releasing, self-etching adhesive system (Transbond Plus Self Etching Primer, 3M). Thirty-six defect-free premolars were randomly divided into 3 groups (n = 12 each), and metal brackets were bonded according to the manufacturer's instructions. Brackets were debonded in shear on a universal testing machine with a crosshead speed of 1 mm per minute. RESULTS: One-way ANOVA showed a statistically significant (P < .001) difference between groups. Group 2 had the highest shear bond strength. The difference between groups 1 and 3 was not statistically significant. The Kruskal-Wallis test showed no significant differences in the ARI scores (P = .595; P < .05). CONCLUSIONS: The fluoride-releasing, antibacterial, self-etching adhesive system, Clearfil Protect Bond, produced greater shear bond strength than the other 2 products tested and could be considered for clinical use.

Acid Etching, Dental↗

The effect of various storage methods and media on shear-bond strengths of dental composite resin to bovine dentine.

A variety of media and methods have been used to store teeth used in bond-strength studies of resin restorative materials to dentine. This study examined the effect of 2 months of storage using 11 different methods and media on the shear-bond strength of Z100 resin composite to bovine dentine mediated by Scotchbond Multi Purpose adhesive. Freshly harvested teeth were used as controls. The results showed that 7 of the l1 storage methods or media were similar in shear-bond strengths and bond-failure characteristics. Four of the 11 methods (irradiation, or storage in thymol, methanol, and glutaraldehyde) resulted in significantly lower shear-bond strengths and atypical shear-bond failure, indicating that these are the least desirable methods of tooth storage for studies of this type. This study has further shown that if insufficient numbers of fresh teeth are available for studies of shear-bond strength, then freezing is the preferred method of storage for the registration of high shear-bond strengths. It is also apparent that further investigations are needed to examine what post mortem changes occur in dentine, whether these changes are modified by various storage conditions, and whether they have any significant effect on bonding of resin composites.

Analysis of Variance↗

Shear bond strengths of tooth fragments reattached or restored.

This study investigated the shear bond strengths of sectioned human mandibular incisor edge fragments reattached using luting cements, bonding agents or restored with composite resins. Seventy teeth were randomly distributed among six experimental groups and a control group. Leaving half of the anatomic crowns exposed, the teeth were embedded in self-cure acrylic resins with the exposed part then sectioned. The fragments in groups 1-4 were bonded to their respective teeth using Clearfil Liner Bond 2V, Scotch Bond Multi Purpose Plus, Panavia-F and 3M Opal Luting cement. The 5th and 6th groups were restored with composite resins (Silux 3M and Clearfil AP-X) using their bonding agents (Single Bond and Clearfil SE Bond). The results indicated that reattachment of fractured incisal fragments by using new generation bonding agents was effective against shear stresses, comparable with the intact teeth. Instead of restoration with composite resins therefore reattachment of a fractured fragment might be more preferable in cases of dental trauma.

Composite Resins↗

The effect of repeated bonding on the shear bond strength of different orthodontic adhesives.

One problem clinicians face during treatment is bracket failure. In a busy orthodontic practice, a significant number of teeth will need to be rebonded. The purpose of this study was to evaluate the effect of repeated bonding with 2 different adhesives, a composite and a cyanoacrylate, on the shear bond strength of orthodontic brackets. Thirty-one freshly extracted human molars were collected. Brackets were bonded with 1 of the orthodontic adhesives according to the manufacturer's instructions. In group I, the teeth were etched with 37% phosphoric acid, a sealant was applied, and the brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif) and light cured for 20 seconds. In group II, the teeth were etched with 35% phosphoric acid, and the brackets were bonded with SmartBond (Gestenco International, Göthenburg, Sweden). In each group, the teeth were bonded and debonded 3 times with the same adhesive. At each sequence, the brackets were removed within 30 minutes after bonding to simulate the clinical condition at which a newly bonded bracket is tied to the archwire. Student t tests and the analysis of variance repeated measure were used to compare the shear bond strength between adhesives and within each adhesive at different debonding sequences. The results indicated that, at the first debonding sequence, the 2 adhesives did not have significantly different shear bond strengths. Between debonding sequence 1 and 2, there was a significant (P <or=.05) decrease in the shear bond strength of both adhesives. SmartBond decreased from x = 5.7 +/- 3.8 MPa to x = 2.2 +/- 2.6 MPa, and Transbond decreased from x = 6.1 +/- 3.4 to x = 4.1 +/- 2.3 MPa. When the 2 adhesives were compared at the second debonding sequence, the shear bond strength of Transbond was significantly greater than that of SmartBond (P =.046). Between debonding sequences 2 and 3, there were no significant differences either between the adhesives or in the change within each adhesive. The highest values for shear bond strength were obtained after the initial bonding. Rebonded teeth had significantly lower shear bond strength. The composite adhesive had a higher shear bond strength than the cyanoacrylate adhesive at the second bonding/debonding sequence but not at the third. The changes in bond strength after repeated bonding may be related to changes in the morphologic characteristics of the tooth surface caused by adhesive remnants.

Analysis of Variance↗

Efficacy of using self-etching primer with a 4-META/MMA-TBB resin cement in bonding orthodontic brackets to human enamel and effect of saliva contamination on shear bond strength.

The objective of this study was (1) to evaluate the effectiveness of Megabond when used with Superbond C&B, a 4-methacryloloxyethyl trimellitate anhydride (4-META)/methyl methacrylate (MMA)-tri-n-butyl borane (TBB) resin, to bond orthodontic metal brackets to human enamel and (2) to examine the influence of saliva contamination on shear bond strength. Metal brackets were bonded to phosphoric acid-etched or Megabond-treated human premolars using Superbond C&B resin cement. The effects of saliva contamination after acid etching or self-etch priming, and the effect of re-etching or self-etch priming after saliva contamination on shear bond strength were also assessed. The shear bond strengths were measured after immersion in water at 37 degrees C for 24 hours. Data were analyzed using two-way analysis of variance and Fisher's protected least significant difference test for multiple comparisons. There were no significant differences in shear bond strength between phosphoric acid etching and self-etch priming for no contamination, saliva contamination, and repeat treatment (etching or priming) after saliva contamination. With phosphoric acid etching, saliva contamination significantly decreased the shear bond strength. Repeat phosphoric acid etching after saliva contamination did not significantly improve the bond strengths. With self-etching primer treatment, however, saliva contamination did not cause any decrease of bond strength. Phosphoric acid etching produced more enamel fracture than self-etching primer treatment. Field-emission scanning microscopy revealed less dissolution of enamel surface resulted from self-etching primer compared with phosphoric acid. These results suggest that Megabond when used with Superbond C&B resin cement may be a good candidate for bonding orthodontic brackets to human enamel.

Acid Etching, Dental↗

Evaluation of shear bond strength and SEM observation of all-in-one self-etching primer used for bonding of fissure sealants.

OBJECTIVES: To evaluate and compare enamel shear bond strength of an all-in-one self-etching primer (Prompt L-Pop) to regular acid etch material when bonded to two-fissure sealant systems (Concise and Dyract Seal). METHOD AND MATERIALS: Forty newly extracted non-carious first permanent molars were embedded in a Teflon mold. The teeth were divided into four groups and each consisted of ten specimens. The bonding surfaces were treated with either Prompt L-Pop as recommended by the manufacturer or etched with phosphoric acid. After 24 hours of water storage, the specimens were evaluated for shear bond strength using an Instron testing machine. Scanning electron microscope (SEM) examinations were carried out to evaluate the failure sites of the sealants. RESULTS: The mean shear bond strengths using Prompt L-Pop were Concise: 23.46 MPa and Dyract Seal: 20.34 MPa. These values were higher than and statistically different from those of Dyract Seal (9.99 MPa) and Concise (8.85 MPa) when phosphoric acid was used. The failure was predominantly of the adhesive type. The SEM examination showed the failure of debonding was predominantly related to the type of etching systems used rather than the type of fissure sealants. CONCLUSION: The use of the all-in-one self-etching adhesive Prompt L-Pop improves the mean enamel shear bond strength of fissure sealants.

Acid Etching, Dental↗

Effect of thermocycling on the shear bond strength of a cyanoacrylate orthodontic adhesive.

The purpose of this study was to evaluate the effects of thermocycling on the shear bond strength of a cyanoacrylate adhesive system, specifically 24 hours after bonding when the adhesive has achieved most of its bond strength and after thermocycling. Forty freshly extracted human molars were collected and stored in a solution of 0.1% (weight/volume) thymol. The teeth were cleaned, polished, and randomly separated into 2 groups: group I, cyanoacrylate adhesive debonded after 24 hours immersion in deionized water at 37 degrees C; and group II, cyanoacrylate adhesive debonded after thermocycling at 5 degrees C and 55 degrees C. The results of the t test comparing the 2 groups (t = 6.84) indicated significant differences between them (P =.0001). The cyanoacrylate adhesive at 24 hours had significantly greater shear bond strength (macro x = 7.1 +/- 3.3 MPa) than after thermocycling 500 times between 5 degrees C and 55 degrees C (macro x = 1.5 +/- 1.4 MPa). The findings indicated that the cyanoacrylate adhesive tested has clinically adequate shear bond strength at 24 hours after initial bonding but loses about 80% of its strength after thermocycling. The clinician should consider all properties of the adhesive, including no need for a curing light, working time of 5 seconds before the adhesive starts to set, and the significant decrease in bond strength after thermocycling.

Cyanoacrylates↗

Effects of conventional and high-intensity light-curing on enamel shear bond strength of composite resin and resin-modified glass-ionomer.

The purpose of this study was to evaluate the shear bond strengths of a composite resin (Transbond XT; 3M/Unitek, Monrovia, Calif) and a resin-modified glass ionomer (Fuji Ortho LC; GC America Inc, Alsip, Ill) cured with 2 different light-curing units: a conventional visible light unit (Ortholux XT; 3M Dental Products, St Paul, Minn) and a xenon arc light unit (Plasma Arc Curing [PAC] System; American Dental Technologies, Corpus Christi, Texas). One hundred twenty freshly extracted bovine permanent mandibular incisors were randomly divided into 1 of 8 groups; each group consisted of 15 specimens. Two groups (1 group for each type of adhesive) were exposed to the visible light for 20 seconds (Transbond XT) and 40 seconds (Fuji Ortho LC), respectively, and used as control groups. The remaining 6 groups (3 for each adhesive) were cured with the xenon arc light for 2, 5, and 10 seconds. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested in a shear mode on an Instron universal testing machine (Instron Corp, Canton, Mass). For the groups bonded with Transbond XT, no statistically significant differences (P =.868) were found between the shear bond strength of the control group cured with Ortholux XT and those of the groups cured with the PAC System for 2, 5, or 10 seconds. When the shear bond strengths of the groups bonded with Fuji Ortho LC were evaluated, no statistically significant differences (P =.087) were found between the control group that was cured with Ortholux XT and those cured with the PAC System. The bond strength of the composite resin was significantly higher than that of the resin-modified glass ionomer in all the groups tested (P <.0001). The present findings indicate that, compared with visible light-curing, the xenon arc light enables the clinician to significantly reduce the curing time of both bonding agents, without affecting their shear bond strengths. Therefore, xenon arc light sources can be recommended as an advantageous alternative for curing both composite resins and resin-modified glass ionomers.

Acid Etching, Dental↗

Effect of mode of polymerization of bonding agent on shear bond strength of autocured resin composite luting cements.

PURPOSE: There have been anecdotal reports of low bond strength with autocured resin composite materials, particularly when light-cured bonding agents that combine primer and adhesive in a 1-bottle preparation are used. The objective of this study was to determine if the mode of polymerization of the bonding agent influences the strength of the attachment of autocured resin composite luting cements to dentin. METHODS: The shear bond strength of 2 resin luting cements, Calibra and RelyX ARC, polymerized by autocuring, in combination with 4 different bonding agents, Scotchbond Multipurpose Plus, Prime & Bond NT, IntegraBond and Single Bond, polymerized to bovine dentin by light-curing, autocuring or dual-curing, was determined. The pH of each bonding agent and its components was measured. Two-way analysis of variance was used to test the effect of cement and adhesive on shear bond strength. For each bonding agent, the adhesive variable combined the factors product brand and mode of polymerization. With significant interaction among the above variables, the least square means of the 16 combinations of resin cement and adhesive were compared. RESULTS: There was no consistent relationship between shear bond strength and mode of polymerization of the bonding agent. Significant differences in bond strength were specific to the proprietary brand of bonding agent. The pH of the bonding agent depends on the manufacturer's formulation, and low pH may contribute to low bond strength. CONCLUSIONS: The low in vitro bond strength occurring with some combinations of bonding agent and resin cement could be clinically significant.

Analysis of Variance↗

Evaluation of 24-hour shear bond strength of resin composite to porcelain according to surface treatment.

PURPOSE: The purpose of the present in vitro study was to examine shear bond strengths of resin composite to porcelain according to surface treatment. MATERIALS AND METHODS: One hundred eight feldspathic porcelain blocks were prepared. Specimens were divided into nine surface treatment groups: sandblasting with 50- or 110-microm Al2O3, acid etching with hydrofluoric acid, applying silane agent, and combinations of these treatments. Microhybrid resin composite was condensed and light cured for 40 seconds on the porcelain specimens, which were then stored in distilled water at 37 degrees C for 24 hours before mechanical testing. RESULTS: The bond strengths were significantly different according to one-way ANOVA. The lowest bond strength was observed in the silane group (4.09 MPa); the highest bond strengths were observed with acid etching + silane (11.97 MPa) and sandblasting with 50-microm Al2O3 + acid etching + silane (12.34 MPa) (no significant difference between groups). CONCLUSION: Acid etching with 9.6% hydrofluoric acid gel or sandblasting with 50- or 110-microm Al2O3 particles alone did not provide adequate bond strength. Silane agent was effective in increasing the shear bond strength of resin composite to porcelain after sandblasting or acid etching. Porcelain treatment with a combination of 50-microm Al2O3 air abrasion, 9.6% hydrofluoric acid, and silane agent provided higher bond strengths than treatment with any of these procedures alone.

Acid Etching, Dental↗

Shear bond strengths of indirect resin composites to hybrid ceramic.

A hybrid ceramic, Estenia, is a highly-filled composite for indrect use. The purpose of this study was to measure the shear bond strength between Estenia and six incremental materials: Estenia, Cesead II, Epricord, Gradia, Prossimo, and Solidex. Five specimens were prepared for each group, and all specimens were subjected to shear bond strength testing at a cross-head speed of 1 mm/min. Data were analyzed using two-way ANOVA and Dunnett's T3 test at 95% confidence level. The results indicated that the shear bond strength of Estenia to Estenia was significantly lower than that of any other combinations. Apart from storage condition that was found to influence shear bond strength statistically, thermal cycling of the specimens also tended to decrease the bond strength between Estenia and the incremental materials. It was concluded that regularly-filled composites are suitable to be used as an incremental material facing Estenia in combination technique.

Analysis of Variance↗

Effect of Nd:YAG laser irradiation on shear bond strength of glass-lonomer luting cement to dentin surface.

PURPOSE: The purposes of this study were to evaluate the shear bond strength of luting glass-ionomer cement to a dentin surface treated by pulsed Nd:YAG laser irradiation, and to prove the hypothesis that the bond strength of glass-ionomer luting cement to dentin is favorably altered after Nd:YAG laser irradiation. MATERIALS AND METHODS: Sixty-four extracted human molars with an exposed flat dentin surface were divided into four groups (n = 16). After painting black ink on their surfaces, the teeth of groups 1, 2, and 3 were irradiated by an Nd:YAG laser at 1.064-microm wavelength at 1, 2, and 3 W, respectively; group 4 was untreated and served as a control. Some specimens of each group were used for morphologic and atomic analytic study, and the others were used for shear bond testing. The shear bond test was performed after cylindric titanium specimens were cemented with glass-ionomer cement on a circular dentin area and specimens were immersed in distilled water. The tested specimens were also morphologically investigated. RESULTS: Shear bond strength of group 3 was significantly higher than that of the control group. Morphologic observation of the cement-dentin interface showed good adaptation of the luting cement to laser-treated dentin. Analysis of atomic contents on the dentin surface showed a significant increase of calcium:phosphorus ratio after laser irradiation. CONCLUSION: The dentin surface was modified morphologically and chemically, and the shear bond strength of glass-ionomer luting cement to dentin was increased by Nd:YAG laser irradiation at 3 W.

Aluminum Silicates↗