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PubMedDate not supplied

The influence of an adhesive system on shear bond strength of repaired high-copper amalgams.

The shear bond strengths of intact high-copper spherical and admixed amalgams were compared with repaired high-copper spherical and admixed amalgam specimens with and without the use of an adhesive system (Amalgambond). In the spherical group the shear bond strength of the repaired specimens was found to be 55 and 53.2% of the intact specimens without and with the use of the adhesive system. After thermocycling those percentages were 48.5 and 43. In the admixed groups those percentages were 39, 36.5, 34.5, and 35.2 respectively. It was found that the application of Amalgambond did not significantly increase the strength of the repaired amalgam. Thermocycling only had a significantly adverse effect on the repair strength in the admixed group repaired without an adhesive system.

Copper↗
PubMed2004

Evaluation of modifying the bonding protocol of a new acid-etch primer on the shear bond strength of orthodontic brackets.

The purpose of the study was to evaluate the shear bond strength of orthodontic brackets when light curing both the self-etch primer and the adhesive in one step. Fourty eight teeth were bonded with self-etch primer Angel I (3M/ESPE, St Paul, Minn) and divided into three groups. In group I (control), 16 teeth were stored in deionized water for 24 hours before debonding. In group II, 16 teeth were debonded within half-an-hour to simulate when the initial archwires were ligated. In group III, 16 additional teeth were bonded using exactly the same procedure as in groups I and II, but the light cure used for 10 seconds after applying the acid-etch primer was eliminated, and the light cure used for 20 seconds after the precoated bracket was placed over the tooth. This saved at least two minutes of the total time of the bonding procedure. The teeth in this group were also debonded within half-an-hour from the time of initial bonding. The teeth debonded after 24 hours of water storage at 37 degrees C had a mean shear bond strength of 6.0 +/- 3.5 MPa, the group that was debonded within half-an-hour of two light exposures had a mean shear bond strength of 5.9 +/- 2.7 MPa, and the mean for the group with only one light cure exposure was 4.3 +/- 2.6 MPa. Light curing the acid-etch primer together with the adhesive after placing the orthodontic bracket did not significantly diminish the shear bond strength as compared with light curing the acid-etch primer and the adhesive separately.

Acid Etching, Dental↗
PubMed2001

[Shear bond strengths of four types of adhesive resin agents to GI II glass infiltrated ceramic].

OBJECTIVE: The shear bond strength of four adhesive resins bonded to GI II glass infiltrated alumina ceramic was investigated in this experiment. METHODS: A total of 40 ceramic blocks and 40 tooth blocks were prepared and divided into 4 experimental groups, including group A (CereDual and silicoating), group B (Calibra and silicoating), group C (Panavia) and group D (Super C&B and silicoating). The shear strength of four different bonding systems to dentin was tested respectively. The data were statistically analyzed. RESULTS: More than 13 MPa of bonding strength was achieved using the traditional Bis GMA bonding resin (groups A and B), and more than 16 MPa was obtained using the improved Bis GMA bonding resin (group C and D). There was statistical difference between groups A, B and group C, D. CONCLUSION: It can be implied that an ideal bonding can be obtained by using different bonding materials and processing the dentin surface with the suitable conditioner.

Dental Bonding↗
PubMed1992

Enamel shear bond strengths after vital bleaching.

This study examined the shear bond strengths of enamel bond formed at specific time intervals after the termination of vital bleaching. A total of 160 extracted human anterior teeth were divided into three bleaching treatment (BTx) groups (Superoxol, Proxigel, White & Brite), two bonding agent (BA) subgroups (Scotchbond Dual Cure, Scotchbond 2) and two BA control groups. After BTx for 30 days, bonds were formed at 1, 6 and 24 hours; 3 and 7 days (time interval, TI) post-termination of BTx. A total of 32 groups of n = 5 were used. Bonds were formed in nylon tubes with selected BA and Silux Plus, and ruptured 24 hours later with Instron and cable/loop to measure enamel shear bond strength (SBS). A 3 x 2 x 5 factorial ANOVA and Tukey 95% confidence interval (TCI) detected significant differences between BTx (F = 3.54; TCI = 2.7 MPa), BA (F = 9.73; TCI = 1.8 MPa) and TI (F = 9.39; TCI = 4.1 MPa). The interaction between BTx and TI was slightly significant (F = 2.02); other interactions were not significant. Post-hoc analysis showed 80% of bonds failed at the interface or by mixed cohesive composite/interfacial failure. Scanning electron microscope observations suggested association of increased density of voids in bond area at TI with lowest mean bond strengths. SBS ranged from 42.3 to 106.8% of control.

Analysis of Variance↗
PubMed2006

Effect of debonding force direction on orthodontic shear bond strength.

INTRODUCTION: The aim of this study was to determine the influence of debonding force direction in shear bond strength testing of orthodontic brackets in vitro. METHODS: One hundred fifty extracted bovine permanent mandibular incisors were randomly divided into 5 groups of 30 specimens each. Before bonding with a composite adhesive, enamel surfaces were etched with 37% phosphoric acid for 30 seconds. Teeth were bonded with mesh-based stainless steel orthodontic brackets. Shear bond strength was measured with a universal testing machine. Debonding forces were directed either parallel to the bracket base (group B), toward the enamel surface (group A: 15 degrees), or away from the enamel surface (group C: 15 degrees; group D: 30 degrees; group E: 45 degrees). RESULTS: Shear bond strength measurements were as follows: 22.90 (SD, 1.72) MPa (group A), 17.90 (SD, 2.63) MPa (group B), 12.99 (SD, 1.71) MPa (group C), 7.93 (SD, 1.14) MPa (group D), and 6.65 (SD, 1.14) MPa (group E). Analysis of variance indicated that shear bond strengths were significantly different between the groups investigated. Mean adhesive remnant index scores ranged between 1.60 in group B and 2.13 in group D. CONCLUSIONS: Shear bond strength measurements were significantly influenced by the direction of the debonding force, indicating the need for control and standardization of this testing parameter in orthodontic shear bond strength testing.

Adhesives↗
PubMed1996

Shear bond strength of several new core materials.

This study compared the shear bond strengths of three core materials: a light activated glass-ionomer cement (VariGlass VLC), a fluoride-release dual cure composite resin (Fluoro Core), and a conventional silver-reinforced glass-ionomer cement (Miracle Mix) when cured to dentin. Fifty-four noncarious molar teeth were extracted, cleaned, mounted in acrylic resin, and sectioned horizontally to expose the dentin surface. Each material was mixed according to manufacturer's instructions, applied in a premade mold to the exposed dentin, and then cured. The specimens were randomized into three group (six teeth from each material) and stored (37 degrees C, 100% humidity) for 15 minutes, 24 hours, and 24 hours and were then thermocycled (5 degrees to 55 degrees C) for 125 cycles. The specimens were tested for shear bond strength with the Instron universal testing machine. The differences among time groups were not statistically significant except for Miracle Mix and VariGlass VLC cements, which showed a greater improvement with thermocycling. This study indicated that the FluoroCore resin exhibited the greatest shear bond strength of the core materials and that VariGlass VLC cement had greater bond strength than Miracle Mix cement except after thermocycling, when VariGlass VLC cement and FluoroCore resin were not significantly different.

Acrylic Resins↗
PubMed1991

The effect of storage and thermocycling on the shear bond strength of three dentinal adhesives.

The purpose of this investigation was to evaluate the effects of time of storage and thermocycling on the shear bond strength of three dentinal adhesives. The shear bond strength of Mirage Bond was significantly greater than that of Scotchbond 2, which was significantly greater than that of Scotchbond Dual Cure (P less than or equal to .05). Thermocycling significantly lowered the shear bond strength of Scotchbond Dual Cure and Scotchbond 2, but not that of Mirage Bond (P less than or equal to .05). Time of storage did not affect the shear bond strength of the other adhesives, but Mirage Bond had a significantly greater shear bond strength after 1 month of storage (P less than or equal to .05). Scanning electron microscopic observations showed that the fracture patterns were all at the smear layer-adhesive interface for Scotchbond Dual Cure, the majority of the fractures were at the primer-adhesive interface for Scotchbond 2, and most of the fractures were cohesive in the bonding agent for Mirage Bond.

Analysis of Variance↗
PubMedDate not supplied

Effect of food-simulating liquids on the shear punch strength of composite and polyacid-modified composite restoratives.

This study evaluated the effects of food-simulating liquids on the shear punch strength of two composites (Tetric Ceram [TC], Vivadent; Esthet X [EX], Dentsply), a conventional (Compoglass [CG], Vivadent) and a posterior polyacid-modified (Dyract Posterior [DP], Dentsply) composite. Thirty-two specimens (10-mm in diameter and 1.6-mm thick) of each material were made, randomly divided into four groups of eight and conditioned for one week as follows--Group 1 (control): air at 37 degrees C; Group 2: distilled water at 37 degrees C; Group 3: 75% ethanol-water solution at 37 degrees C and Group 4: heptane at 37 degrees C. After conditioning, the specimens were restrained within the test apparatus and subjected to shear punch strength testing using a 3.2 mm diameter punch at a crosshead speed of 0.5 mm/minute. The shear punch strength of the specimens was computed and the data was subjected to ANOVA/Scheffe's tests at significance level 0.05. The effect of food-simulating liquids on shear strength was found to be material dependent. All materials with the exception of EX were significantly weakened by ethanol solution. For DP, a significant increase in strength was observed after conditioning in water. EX was significantly stronger than TC and DY after conditioning in air, water and ethanol solution. The shear punch strength of EX and CG was significantly higher than DY after conditioning in heptane.

Analysis of Variance↗
PubMed2005

Effect of saliva contamination on shear bond strength of orthodontic brackets when using a self-etch primer.

The effect of saliva contamination on the shear bond strength of orthodontic brackets, at various stages of the bonding procedure using a new self-etch primer was studied. The samples were divided into 4 groups according to 4 different enamel surface conditions: Group A: dry; Group B: saliva contamination before priming; Group C: saliva contamination after priming, and Group D: saliva contamination before and after priming. Stainless steel brackets were bonded in each test group with a light-cured composite resin (TransbondXT 3M). The shear bond strength was determined in the first 30 min after bonding. The analysis of variance indicated that the shear bond strengths of the 4 groups were significantly different (F = 11.89, P < 0.05). Tukey HSD tests indicated that contamination both before and after the application of the acid-etch primer resulted in a significantly lower (=4.6 +/- 1.7 MPa) shear bond strength than either the control group (=8. 8 +/- 1.9 MPa) or the groups where contamination occurred either before ( = 7.9 +/- 2.0 MPa) or after (= 6. 9 +/- 1.5 MPa) the application of the primer. It was concluded that the new acid-etch primer could maintain adequate shear bond strength if contamination occurred either before or after the application of the primer. On the other hand, contamination both before and after the application of the primer could significantly reduce the shear bond strength of orthodontic brackets.

Acid Etching, Dental↗
PubMed2003

Shear bond strength comparison between direct and indirect bonded orthodontic brackets.

The purpose of this study was to compare the shear bond strength of orthodontic brackets bonded to teeth with either an indirect bonding technique and a new adhesive resin or a direct bonding technique and a light-activated adhesive. Fifty-four extracted premolars were mounted in acrylic blocks and randomly divided into 2 groups (n = 27). In one group, orthodontic brackets were bonded to premolars with an indirect bonding adhesive system; in the other, brackets were bonded with the direct method. Seventy-two hours later, the brackets were placed in a testing machine and subjected to a shear force with a crosshead speed of 1 mm/minute. The mean shear bond strengths for the indirect and direct groups were 11.2 and 10.9 MPa, respectively, both exceeding the minimum shear bond strength range of 5.9 to 7.8 MPa often cited in the literature for clinical success. Data were analyzed with Student t tests. No significant difference in shear bond strength between the 2 groups was detected (P =.76). Resin remnants on orthodontic bracket pads were observed with a dissecting microscope at 30x magnification and scored with a modified adhesive remnant index. There was no significant difference between groups (P >.05). There was also no correlation between shear bond strength and the percentage of adhesive resin remnants left on the orthodontic bracket. Under the conditions of this study, no evidence suggests a difference in shear bond strength of orthodontic brackets bonded to tooth enamel, whether they are bonded with the direct or indirect technique.

Dental Bonding↗
PubMedDate not supplied

Shear rebond strength of Rexillium III to enamel using resin composite cements.

This investigation evaluated the shear rebond strength of Rexillium III to enamel using various resin composite luting systems (Panavia, Imperva Dual, ABC Enhanced, C&B Metabond, Optibond, and Comspan). Cast Rexillium III cylinders (3.9 x 6.0 mm) were bonded to human molar buccal enamel surfaces (n = 8) with each cement type after etching with 37% phosphoric acid for 30 seconds. Bonded specimens were stored in distilled water for 7 days at 37 degrees C +/- 2 degrees C and thermocycled (1,500 cycles) in 5 degrees C and 55 degrees C water baths (1 minute dwell time). Specimens were randomly tested in shear mode on an Instron Testing Machine at a crosshead speed of 0.5 mm per minute. Debonded specimens were then rebonded after appropriate metal conditioning and re-etching the enamel surface for 30 seconds. Analysis of variance (P < 0.001) and the Ryan-Einot-Gabriel-Welsh multiple range test showed significant differences between several of the resin cements (P < 0.05). Panavia exhibited significantly higher shear rebond strength than any of the other cements tested. Only Imperva Dual exhibited a significantly lower shear rebond strength compared to its initial shear bond strength.

Acid Etching, Dental↗
PubMedDate not supplied

Shear bond strength of composite resin to amalgam: an experiment in vitro using different bonding systems.

The shear bond strength between amalgam and composite resin with and without the use of adhesive systems was evaluated. It was found that the application of Cover-Up II or Prisma Universal Bond prior to placement of composite resin enhanced the shear bond strength between amalgam and composite resin more than five times; and a shear strength of 4.34 and 4.30 MPa was measured respectively. Acid-etching of the roughened amalgam surface prior to application of Prisma Universal Bond decreased the bond strength by nearly 45%.

Adhesiveness↗
PubMed2003

Shear bond strength of aesthetic materials bonded to Ni-Cr alloy.

OBJECTIVES: This study was undertaken to evaluate the shear bond strength of four materials used as aesthetic material bonded to Ni-Cr alloy. METHODS: Sixty-eight alloy discs were prepared and divided equally into four groups, and received four treatments for veneering: conventional feldspathic porcelain (Noritake EX-3) and three light-cured prosthodontic composite resins (Artglass, Solidex and Targis). The aesthetic materials were applied after metal structure conditioning in accordance with the manufacturers' recommendations. The specimens were stored in distilled water at 37 degrees C for 7 days. A universal testing machine was used to measure the shear bond strength of the specimens at a cross head speed of 0.5 mm/min. Fractured specimens were examined by using both optical and scanning electron microscope. RESULTS: The analysis of variance and Tukey's test showed that the strongest mean shear bond was obtained with Noritake EX-3 (mean shear bond strength 42.90+/-7.82 MPa). For composites, the highest mean shear bond strength was observed for Targis (12.30+/-1.57 MPa); followed by Solidex (11.94+/-1.04 MPa) and Artglass (10.04+/-0.75 MPa). Optical analysis of the fractured surfaces indicated that for Targis and Noritake EX-3 all failures were a mixture of both cohesive and adhesive patterns. As for Artglass and Solidex, the fractures were mainly adhesive in nature. CONCLUSIONS: The Solidex system was equivalent to the Targis system in bond strength and exhibited greater strength than the Artglass system. The porcelain fused-to-metal showed considerably higher shear bond strength than the three metal-resin bonding techniques.

Chromium Alloys↗
PubMed1990

[Shear bond strength between composite inlay and luting composite resin].

The shear bond strength between composite inlay materials and luting composite resins was measured under different storage conditions and using different finishing techniques. The initial shear bond strength was distinctly higher with light-cured composites subjected to secondary light and heat cure (56.7-81.1 MPa) than with a heat- and pressure-cured material, where appreciable bond strength was achieved only after sandblasting of the composite surface (18.8 MPa). In general, water storage of the samples for 30 days with intermittent thermocycling adversely affected the bond strength. The influence of secondary light and heat curing on the bond strength of primarily light-cured composites was highly dependent on the material used.

Composite Resins↗
PubMed1999

Shear bond strengths of two resin-modified glass ionomer cements to porcelain.

Shear bond strength of a composite resin adhesive (Concise) and two resin-modified glass ionomer cements (Fuji Ortho LC and Geristore) bonded to porcelain surface was tested. Orthodontic brackets were bonded to 120 porcelain disks (Finesse) etched with 9% HF. Samples were divided into six groups: (1) Concise, (2) Concise/silane, (3) Geristore, (4) Geristore/silane, (5) Fuji, (6) Fuji/silane. No statistical difference in mean shear bond strength was found between silanated Concise (15.8 MPa), Geristore (19.4 MPa), and Fuji (18.5 MPa) groups, which were significantly higher than nonsilanated groups. Porcelain fracture was observed in all silanated groups and nonsilanated Geristore group. We conclude that (1) silane increases bond strength to porcelain significantly for composite resin and resin-modified glass ionomer cement, (2) Concise, Geristore, and Fuji Ortho LC provide comparable shear bond strength to porcelain.

Acrylic Resins↗
PubMed2004

A comparison of shear bond strength and debonding characteristics of conventional, moisture-insensitive, and self-etching primers in vitro.

Bond failure is often attributed to moisture contamination. To overcome this commonly encountered problem, materials have been developed that are hydrophilic and that are believed to offer better bond strength in moisture-contaminated environment. Shear bond strength was compared among three materials: conventional Transbond XT primer (3M Unitek), moisture-insensitive primer (MIP, 3M Unitek), and self-etch primer (Transbond plus, 3M Unitek). Bond strength was tested under laboratory conditions with brackets bonded on both dry enamel and enamel contaminated with natural saliva. Self-etch primer showed maximum bond strength under both dry and wet conditions. Conventional primer was comparable with the former under dry conditions but did not offer clinically adequate bond strength in cases of moisture contamination. Both MIP and self-etch primer showed adequate bond strength superior to that of conventional primer in case of moisture contamination. All primers showed typical debonding characteristics of separation at the bracket-adhesive interface or within the adhesive itself, with the exception of the conventional primer used with moisture-contaminated enamel.

Acid Etching, Dental↗
PubMed2006

Shear bond strength of new and recycled brackets to enamel.

The purpose of this study was to evaluate in vitro the shear bond strength of recycled orthodontic brackets. S2C-03Z brackets (Dental Morelli, Brazil) were bonded to the buccal surfaces of 50 extracted human premolars using Concise Orthodontic chemically cured composite resin (3M, USA). The teeth were randomly assigned to 5 groups (n=10), as follows. In group I (control), the bonded brackets remained attached until shear testing (i.e., no debonding/rebonding). In groups II, III and IV, the bonded brackets were detached and rebonded after recycling by 90-microm particle aluminum oxide blasting, silicon carbide stone grinding or an industrial process at a specialized contractor company (Abzil-Lancer, Brazil), respectively. In group V, the bonded brackets were removed and new brackets were bonded to the enamel surface. Shear bond strength was tested in an Instron machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. There was no statistically significant difference (p>0.05) between the control brackets (0.52 kgf/mm2), brackets recycled by aluminum oxide blasting (0.34 kgf/mm2) and new brackets attached to previously bonded teeth (0.43 kgf/mm2). Brackets recycled by the specialized company (0.28 kgf/mm2) and those recycled by silicon carbide stone grinding (0.14 kgf/mm2) showed the lowest shear strength means and differed statistically from control brackets (0.52 kgf/mm2) (p<0.05). In conclusion, the outcomes of this study showed that bracket recycling using 90-microm aluminum oxide particle air-abrasion was efficient and technically simple, and might provide cost reduction for orthodontists and patients alike.

Analysis of Variance↗
PubMed2000

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.

Analysis of Variance↗