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PubMed1980

Shear bond strength of porcelain-fused-to-alloys of varying noble metal contents.

The conclusions drawn from the present investigation are as follows: 1. The modification of waxing the metal rods prior to investing the baked porcelain disk in the dental stone eliminated the undesirable bond between the dental stone and the metal rod. The shear bond strengths obtained were believed to be true shear bond strengths. 2. Ceramo-metal restorations should be cooled at a slow rate, so that the alloy and the porcelain have approximately the same cooling rate. 3. Shear bond strengths developed in porcelain-metal composites were in descending order for Biobond, Vita, and Ceramco porcelain. 4. Push-test shear bond strengths were always higher than pull-test shear bond strengths. Both push- and pull-tests seemed to be equally valid for evaluating bond strengths in porcelain-metal composites. 5. The porcelain-metal composite of the silver-free gold alloy showed higher shear bond strengths for all porcelains.

Dental Alloys↗
PubMedDate not supplied

An in vitro shear bond strength study of enamel/dentin bonding systems on enamel.

The purpose of this study was to compare the enamel shear bond strengths achieved with four acid conditioners employed by current enamel/dentin bonding systems (maleic acid, citric acid, nitric acid, oxalic acid) with a 37% phosphoric acid etching technique. The study also compared enamel shear bond strengths between the manufacturers' enamel/dentin conditioner used with an unfilled enamel bonding resin. The facial surfaces of 135 bovine incisors were ground flat and divided into nine test groups of n=15. Conditioning and bonding procedures were carried out following manufacturers' instructions. The phosphoric acid groups were etched for 15 seconds, rinsed for 30 seconds, and dried for 20 seconds with compressed air. All bonding was accomplished at a constant temperature of 21 degrees C and a relative humidity of 60%. A single composite restorative resin (Z-100) was used with all specimens to eliminate variables between composite materials. All specimens were thermocycled 2500 times (5 to 45 degrees C) and had a total storage time of 21 days prior to shear testing on an Instron at a crosshead speed of 1.0 mm/minute. Shear strengths were calculated by dividing load at failure by specimen area. A light microscope was used to determine failure mode. The data were subjected to Bartlett's test for homogeneity of variance and were found not to be homogeneous. The Welch Test was applied and indicated that the treatments used had influence on bond strength at P<0.05. There was no significant difference in bond strength values between traditional phosphoric acid/enamel bonding resin and Mirage Bond Dentin and Enamel Adhesive, Clearfil Liner Bond System, and Scotchbond Multi-Purpose Dental Adhesive System.

Acid Etching, Dental↗
PubMed2005

Effect of changing a test parameter on the shear bond strength of orthodontic brackets.

The purpose of this study was to determine the effect of changing the crosshead speed of the testing machine on the shear bond strength of orthodontic brackets to enamel while standardizing all the other variables. Forty freshly extracted human molars were bonded using the Transbond XT adhesive system (3M Unitek, Monrovia, Calif). The teeth were randomly divided into two groups. In group I, the shear bond strength was measured at a crosshead speed of 5.0 mm/min, and in group II the shear bond strength was measured at a crosshead speed of 0.5 mm/ min. Within half an hour from the initial bonding of each tooth, an occlusogingival load was applied to the bracket, producing a shear force at the bracket-tooth interface. This was accomplished by using the flattened end of a steel rod attached to the crosshead of a Universal Test Machine (Zwick GmbH & Co, Ulm, Germany). The t-test results (t = 2.71) indicated that there was a significant difference (P = .014) in the shear bond strengths between the group tested at a crosshead speed of 5.0 mm/min and the group tested at a crosshead speed of 0.5 mm/min. The mean shear bond strengths for the two groups were 7.0 +/- 4.6 MPa and 12.2 +/- 4.0 MPa, respectively. These findings indicated that it is important to identify the parameters included in shear bond testing in order to enable meaningful comparisons of the performance of different materials.

Dental Bonding↗
PubMed2005

Influence of photopolymerization light source on enamel shear bond strength after bleaching.

This study evaluated the influence of 3 different photopolymerization sources on enamel shear bond strength after bleaching with 10% carbamide peroxide. Seventy-two incisive bovine teeth were randomly divided into 6 groups (n=12) according to bleaching treatment and photopolymerization source used: G1 -- Bleached / Halogen lamp; G2 -- Not bleached / Halogen lamp (control); G3 -- Bleached / Light-emitting diodes (LED); G4 -- Not bleached / Light-emitting diodes (LED) (control); G5 -- Bleached / Xenon plasma arc; G6 -- Not bleached / Xenon plasma arc (control). Experimental groups were exposed to bleaching agent for a period of 14 days, with a daily contact of 4 h and then stored in artificial saliva at 37 degrees C. Control groups were stored in artificial saliva at 37 degrees C for same period of bleaching treatment. Procedures for bonding composite resin to enamel were carried out according to manufacturer instructions. After storage in distilled water at 37 degrees C for 24 hours, all samples were submitted to shear bond strength test. G2 had the highest mean value (14.86 MPa) while G5 had the lowest (12.32 MPa). The comparison of groups by 2-way ANOVA showed that there were no significant differences for either of the factors considered in this study (bleaching and photopolymerization source), hence the interaction between these factors. It was therefore possible to conclude that neither enamel bleaching nor the photopolymerization source used had any influence on enamel shear bond strength.

Analysis of Variance↗
PubMed2005

Shear bond strengths of two composite core materials after using all-in-one and single-bottle dentin adhesives.

PURPOSE: The purpose of this study was to compare the shear bond strengths of 2 composite core materials after using all-in-one and single-bottle dentin bonding materials. MATERIAL AND METHODS: The occlusal surfaces of 100 extracted, intact human third molars were ground to expose a flattened area of dentin and polished with 600-grit silicon carbide paper. Specimens were divided into 5 main groups (n= 20). Three all-in-one (AQ Bond, One-Up Bond, Xeno-CF Bond) and 2 single-bottle adhesives (Single Bond, One-Step Plus) were used. Each group was further divided into 2 subgroups. Ti-Core and Built-it F.R. core materials were applied using a translucent plastic ring (diameter: 3 mm, height: 5 mm). After storage in 37 degrees C water for 24 hours, shear bond strengths were measured using a Universal testing machine with a crosshead speed of 0.5 mm/min. Debonded dentin surfaces were examined with SEM. Two-way analysis of variance (ANOVA) and multiple comparison (Tukey) tests were used for statistical analysis of data. RESULTS: Two-way ANOVA revealed that the type of core material did not significantly influence the shear bond strength (p > 0.05), whereas there were significant differences in shear bond strength among the types of bonding agents (p < 0.0001). Shear bond strengths for single-bottle adhesive systems were significantly higher than those for all-in-one adhesive systems (p < 0.05). Furthermore, the interaction of these 2 parameters was not significant (p > 0.05). The fracture modes were predominantly adhesive for all-in-one adhesives and cohesive for single-bottle adhesives. CONCLUSION: Bonding of composite core materials with the newly developed all-in-one dentin adhesives produced lower shear bond strengths as compared with single-bottle adhesives.

Analysis of Variance↗
PubMed2000

Shear bond strengths of orthodontic plastic brackets.

The purpose of the present study was to evaluate the shear bond strengths of plastic brackets and the influences of the bracket filler contents on the bonding. The shear bond strengths of 4 plastic brackets (Spirit; Spirit MB; Clear Bracket; Aesthetic-Line) bonded to enamel with 4 orthodontic adhesives (Orthomite Superbond; System 1+; Transbond XT; and Kurasper-F) were compared with the strength of a conventional metal bracket. The findings of this study indicated the following: (1) shear bond strength of the 4 plastic brackets was significantly lower than that of the conventional metal brackets (P <.05), with most of the values ranging from 3 MPa to 6 MPa; (2) when comparing the bond strengths of plastic brackets, Aesthetic-Line had the largest value followed by Spirit MB, Spirit, and Clear Bracket, and when the plastic brackets were bonded with Orthomite Superbond, they showed relatively stronger bond strengths than when bonded with the other adhesives. Clear Bracket showed relatively lower values especially when bonded with System 1+; (3) the application of primer did not increase the durability of the bond strengths when bonding Spirit and Clear brackets; and (4) fillers contained in each plastic bracket ranging from 9.18% to 19. 52% were fairly well distributed and showed the same morphology of a fiber type 10 microm in diameter with different lengths. The filler concentration tended to correlate with the bond strength. The exposed fillers on the bracket base surface may play a more important role in plastic bracket adhesion than the macro-morphology of the base surface.

Dental Bonding↗
PubMed2005

Shear bond strength of five porcelain repair systems on cerec porcelain.

The purpose of this in vitro investigation was to evaluate the shear bond strength of composite resin bonded to Cerec Vitablocs Mark II porcelain with four different porcelain repair systems. The systems evaluated in this study were Scotchbond/ RelyX Primer (S/ 3M), Ultradent Porcelain Repair Kit (U, Ultradent), Vivadent Ceramic Repair Kit (V, Vivadent) and Prime & Bond NT/ Calibra Silane Coupling Agent (P, Dentsply). Seventy five Cerec Vitablocks Mark II porcelain were embedded in metal rings, leaving 7 mm of porcelain exposed above the ring surface. Samples were ground wet on 400 grit SiC paper to roughen the surface and then screened for surface defects. The five porcelain repair agents were applied according to manufacturers' instructions and matching composite stubbs, then bonded onto 15 treated porcelain surfaces, using an Ultradent mould with a diameter of 2,38 mm. All samples were stored in distilled water for 24 hours at 37 degrees C before the bonds were stressed to failure, using a shear load in a Texture Analyser (TAXT2i) (Stable Micro Systems) Data was analyzed statistically (ANOVA). The effects of the pretreatments on the porcelain surfaces after treatment with the different systems were examined in a Scanning Electron Microscope (SEM), and the modes of fracture were assessed under a light microscope. The mean SBS (MPa) for the products in descending order were: U = 26.6 1.7; V = 20.9 3.4; C = 19.4 5.3; S = 18.0 2.0 and P = 15.9 2.1. The Student-t Test revealed a statistical significant difference (p < 0.05) between the mean shear bond strengths of P and U. There was also a statistical significant difference (p < 0.05) between the mean shear bond strengths of P and V. Most debonded specimens showed cohesive fractures in the porcelain. Significant shear bond strength differences were observed for the different repair systems. All the systems tested can probably be used to repair Cerec Vitablocs Mark II porcelain, with some systems providing higher bond strengths.

Acrylic Resins↗
PubMed1989

In vitro investigation of shear bond strength of a phosphate based dentinal bonding agent.

The objective with this study was to investigate how the shear bond strength of a phosphate based dentinal bonding agent is influenced by storage in saline at 37 degrees C up to 6 months. The effect of dentin bonding agent on the leachability of calcium from dentin was also determined. The results showed that the shear bond strength decreased after saline storage. After half a year, the strength was ca. 60% of the initial dry strength. The bonding agent also accelerated the leaching of calcium from the dentin discs, a finding which was explained as being a result of acidic reactions occurring at the dentin-bonding agent interface. In addition to the increased calcium leachability, the dentin bonding agent peeled off with time from the dentin discs. SEM investigation of the dentin surfaces after either shear strength determination or the film had peeled off due to water storage showed that a residual film was left on the dentin. This film, based on morphologic appearance, is most likely composed of the bonding agent but may also contain residuals of the smear layer.

Adhesives↗
PubMed2002

Effect of time on the shear bond strength of cyanoacrylate and composite orthodontic adhesives.

The purpose of this study was to compare the effects of time on the shear bond strength of a cyanoacrylate system and a composite adhesive system (1) within half an hour after bonding the bracket to the tooth, and (2) after 24 hours from the time of bonding when the adhesive had achieved most of its bond strength. Eighty freshly extracted molars were collected and stored in a solution of 0.1% (weight/volume) thymol. The teeth were cleansed, polished, and randomly separated into 4 groups: (I), cyanoacrylate adhesive debonded within one-half hour from initial bonding; (II), cyanoacrylate adhesive debonded after 24 hours immersion in deionized water at 37 degrees C; (III), composite adhesive debonded within one-half hour from initial bonding; (IV), composite adhesive debonded after 24 hours immersion in deionized water at 37 degrees C. The results of the analysis of variance comparing the 4 experimental groups (F = 12.68) indicated significant differences between them (P =.0001). The composite adhesive at 24 hours had significantly greater shear bond strength than did the other 3 groups. In general, the shear bond strengths were greater in the 2 groups debonded after 24 hours. This was true for both the cyanoacrylate ((-)x 7.1 +/- 3.3 megaPascals [MPa]) and the composite ((-)x 10.4 +/- 2.8 MPa) adhesives. On the other hand, the shear bond strength was significantly lower in the 2 groups debonded within one-half hour of their initial bonding. The bond strength of the cyanoacrylate adhesive ((-)x 5.8 +/- 2.4 MPa) was not significantly different from that of the composite ((-)x 5.2 +/- 2.9 MPa) adhesive. Our findings indicated that the cyanoacrylate and the composite adhesives tested have clinically adequate shear bond strengths at half an hour and at 24 hours after initial bonding. The clinician needs to consider the properties of each adhesive: eg, the need to use a curing light and the ability to have more working time with the composite adhesive versus no light but only a 5-second working time before the cyanoacrylate adhesive starts to set.

Analysis of Variance↗
PubMed2005

Influence of force location in orthodontic shear bond strength testing.

OBJECTIVE: The purpose of the present study was to analyze the influence of debonding force location in shear bond strength testing of orthodontic brackets in vitro. METHODS: Ninety extracted permanent bovine mandibular incisors were randomly divided into 3 groups of 30 specimens each. Teeth were bonded with stainless steel orthodontic brackets. Enamel surfaces were etched with 37% phosphoric acid for 30s and bonded with a composite adhesive. Debonding force measurements were performed with a universal testing machine. Location of the debonding force was: bracket base (group A), ligature groove (group B), occlusal bracket wings (group C). RESULTS: Mean shear bond strength measurements were as follows: 22.70(4.23)MPa (group A), 11.52(2.74)MPa (group B), 9.44(2.96)MPa (group C). Analysis of variance indicated that there were significant differences in shear bond strength. Post-hoc Tukey tests showed that bond strength measurements of group A were significantly different from those of groups B and C. The adhesive remnant index also showed significant differences and ranged from a mean of 1.53 in group A to a mean of 2.10 in group C. SIGNIFICANCE: Debonding force location had a significant influence on shear bond strength measurements and bond failure pattern, indicating that this parameter needs to be taken into consideration for interstudy comparison of in vitro results.

Analysis of Variance↗
PubMedDate not supplied

Shear bond strength of indirect resin to NiCr with different metal surface preparations.

This study sought to evaluate the shear bond strength of indirect resin to nickel chromium (NiCr) after different surface preparations. Sixty-four metal samples were divided into four groups, according to surface preparation, and two layers of opaque resin and three layers of body resin were applied. Each group was divided into two subgroups based on storage period in distilled water at 37 degrees C. Mechanical shear testing was performed using a universal testing machine with 0.5 mm/minute of cross-head speed. Debonded areas were analyzed and classified according to different failure types, such as cohesive, adhesive, and mixed. The storage periods were compared using a student T-test (alpha = 0.05); Group T (that is, the tin electroplating group) showed the highest average after 24 hours. The macro retentions showed higher shear bond strength than the sandblasted samples (p < 0.05). Tin electroplating did not improve the shear bond strength of metal-resin bonding. The results were not affected by 30-day storage, with the exception of group T (p < 0.05).

Aluminum Oxide↗
PubMed1993

An investigation on the shear bond strength of three dentine adhesives.

The aim of this investigation was to compare the shear bond strengths of three dentine adhesives tested using an Instron Universal Testing machine at a crosshead speed of 0.5 mm/min. Sixty human molar teeth were used and divided into 3 equal groups where the occlusal surfaces were ground and adhesives were applied overlaid by composite material. Samples were fixed to the Universal Testing machine. Results were recorded in kg/cm2 and converted into MPa units then tabulated and statistically analyzed. Duncan's multiple range statistic test at p < 0.05 showed no statistically significant difference between the shear bond strength values of Scotchbond 2 and Amalgambond; whereas the shear bond strength values of Scotchbond 2 and Amalgambond were significantly higher than those of Gluma. Scanning electron microscopic examinations at X10 and X2500 magnifications showed a dominant adhesive pattern of failure in the samples treated with Gluma, and a mixture of cohesive and adhesive-cohesive patterns of failures in the samples treated with Scotchbond 2 and cohesive patterns of failures in the samples treated with Scotchbond 2 and Amalgambond.

Adult↗
PubMed1992

The relative shear bond strength of visible light-curing and chemically curing glass-ionomer cement to composite resin.

The purpose of this study was to compare the shear bond strength to composite resin of a light-curing glass-ionomer cement with that of various chemically curing glass-ionomer cements. Light-cured composite resin cylinders were bonded to cylindrical glass-ionomer substrates after etching for 30 seconds with 37% phosphoric acid. Specimens were maintained in distilled water for 7 days and then thermocycled in water baths. One group of light-cured glass-ionomer cement substrates was not etched. The interfacial bond strength of these specimens was measured in shear. Cement shear strength was also evaluated. Statistical analysis showed the light-curing cement to have a significantly higher bond strength to composite resin than any of the chemically curing cements tested.

Analysis of Variance↗
PubMed1993

Shear bond strength of a mechanically retained ceramic bracket.

The failure under shear loading of mechanically retained ceramic brackets bonded to enamel was investigated. One light-activated dual-cure and two no-mix self-cure adhesives were compared to all Adhesive Pre-coated bracket (APC). The results indicated that the ceramic bracket bonded with the light-activated dual-cure adhesive had a significantly higher mean shear bond strength than the other adhesive systems. All adhesive systems usually failed cohesively with adhesive remaining attached to the bracket and enamel surfaces. There was no significant difference in failure site. There was a significant difference in the amount of adhesive remaining attached to the enamel surface. The light-activated dual-cure adhesive and Adhesive Pre-coated brackets failed in 50% and 80% of instances respectively, with less than 10% of the adhesive remaining attached to the enamel surface. Self-cure adhesives failed usually with 10-90% of the adhesive remaining attached to the enamel surface. There were no instances of enamel damage. Three cases of bracket fracture occurred, one of these being associated with the highest recorded bond strength.

Acid Etching, Dental↗
PubMed1997

Shear bond strength of a new one-bottle dentin adhesive.

PURPOSE: To test the shear bond strength of a new adhesive, 3M Single Bond, to dentin surfaces containing different degrees of moisture. Two commercially available one-bottle adhesives (Prime & Bond, One-Step) and a conventional three-step system (Scotchbond Multi-Purpose Plus) were included for comparison. MATERIALS AND METHODS: 120 bovine teeth were embedded in acrylic and the labial surfaces were polished to 600 grit to create standardized dentin surfaces for testing. Resin composite was bonded to dentin using a gelatin capsule technique. Four adhesive systems were evaluated with three different degrees of surface moisture (moist, wet, and overwet). Shear bond strengths of adhesives to dentin were determined using a universal testing machine and analyzed by ANOVA and Tukey's post hoc tests. RESULTS: Single Bond had mean shear bond strengths of 19.2, 23.2 and 20.3 MPa to moist, wet, and overwet dentin, respectively. Bond strengths of the three-component system Scotchbond Multi-Purpose Plus ranged from 23.1 to 25.3 MPa, but were not significantly higher than the values for Single Bond. Prime & Bond had bond strengths similar to those of Single Bond, but One-Step had significantly lower bond strengths (P < 0.05) in the wet and overwet conditions.

Analysis of Variance↗
PubMed1996

Effects of fluoride application on shear bond strength of orthodontic brackets.

The purpose of this study was to determine the shear bond strength and debonding failure modes of orthodontic brackets bonded to teeth that have been treated with various fluoride concentrations. Thirty-six recently extracted human premolars were divided into three groups: prophylaxis with pumice only, prophylaxis using a 13,500 ppm fluoridated pumice, and prophylaxis with pumice followed by application of a 2500 ppm fluoridated paste. The teeth were etched with a 37% phosphoric acid gel, then bonded with a metal orthodontic bracket. The teeth were mounted in phenolic rings and stored in de-ionized water at 37 degrees C for 72 hours. A Zwick Universal Testing Machine was used to determine shear bond strengths. The residual adhesive on the enamel surface was estimated using the Adhesive Remnant Index. Analysis of variance was used to compare the various groups, and significance was predetermined at p < or = 0.5. The results indicate that there were no significant differences in bond strengths between the treated and untreated teeth (p = .233). The Chi Square test evaluating the residual adhesive on the enamel surfaces also showed no significant differences (p =.456). In conclusion, the use of fluoridated prophylactic pastes with varying fluoride concentrations does not significantly affect shear bond strength or bond failure location.

Acid Etching, Dental↗
PubMed1998

Shear bond strength of a titanium reinforced core material after using multistep and single-step bonding agents.

STATEMENT OF PROBLEM: Recently introduced single-step bonding agents reduce the number of steps involved in the bonding process. Nevertheless, there are few studies on the bond strengths obtained with these new systems. PURPOSE: This in vitro study evaluated the shear bond strength of a titanium-reinforced cores bonded with 5 multistep bonding systems (ScotchBond Multi-Purpose, OptiBond, All Bond-2, Tenure, and ProBond) and 5 single-step bonding systems (Single-Bond, OptiBond Solo, One-Step, Tenure Quik, and Prime & Bond 2.1). MATERIAL AND METHODS: The experiment was divided into 10 groups with 10 specimens per group. The shear bond strengths were evaluated after 24 hours on an MTS universal testing machine with a crosshead speed of 6.35 mm/minute. RESULTS: A 2-way ANOVA showed that All Bond-2 and One-Step recorded the highest means and differed significantly from the Den-Mat systems (Tenure A&B and Tenure Quik), the Kerr systems (OptiBond and Opti-Solo), and the Caulk systems (ProBond and Prime & Bond 2.1). ProBond and Prime & Bond 2.1 bonding systems had the lowest mean and differed from the 3 other brands. Tenure A&B and Tenure Quik bonding systems and OptiBond and Opti-Solo bonding systems did not differ from one another. CONCLUSION: The single-step bonding agents did not produce an improvement in shear bond strengths. The wide range of shear bond strength reported for the single-step systems appeared to indicate that these bonding systems are technique sensitive.

Analysis of Variance↗
PubMed2004

Evaluation of shear bond strength with different enamel pre-treatments.

The purpose of this study was to investigate the shear bond strengths of two adhesives, Panavia-21 and a composite resin (Transbond XT), with different enamel pre-treatments, acid etching (37 per cent phosphoric acid) and grit blasting (50 microm aluminium oxide particles). The mode of bond failure was also assessed using the modified adhesive remnant index (ARI). Ninety freshly extracted non-carious human premolar teeth were randomly divided into the following groups: (1) Transbond XT, acid-etched enamel surface; (2) Panavia-21, acid-etched enamel surface; (3) Transbond XT, grit-blasted enamel surface; (4) Panavia-21, grit-blasted enamel surface; (5) Transbond XT, acid-etched enamel surface with grit-blasted brackets; (6) Panavia-21, acid-etched enamel surface with grit-blasted brackets. All groups had stainless steel brackets bonded to the buccal surface of each tooth. An Instron universal testing machine was used to determine the shear bond strengths at a crosshead speed of 0.5 mm/second. Statistical analysis was undertaken using analysis of variance and the Tukey test. The mean bond strength values were as follows: group 1, 135.7 +/- 23.0 N; group 2, 181.5 +/- 18.4 N; group 3, 38.4 +/- 27.5 N; group 4, 59.1 +/- 24.1 N; group 5, 106.7 +/- 21.5 N; group 6, 165.3 +/- 21.4 N. Panavia-21 with the acid-etched enamel surface had a significantly higher shear bond strength than the other groups (P < 0.001). This was followed by the composite group with the acid-etched enamel surface. This group differed significantly from the composite and Panavia-21 groups with the grit-blasted tooth surface (P < 0.001) and from the composite and Panavia-21 groups with the acid-etched enamel surface and grit-blasted brackets (P < 0.01). The current findings indicate that Panavia-21 is an excellent adhesive and produces a bond strength that is clinically useful. Enamel surface preparation using grit blasting alone results in a significantly lower bond strength and should not be advocated for clinical use.

Analysis of Variance↗