Evaluation of the effects of three pretreatment conditioners and a surface preparation system on the bonding durability of composite resin adhesive to a gold alloy.

This study aimed to evaluate the effect of three pretreatment conditioners and surface preparations on a composite resin adhesive for a gold alloy. Cast disk specimens were made and bonded with RelyX Unicem luting agent under six surface conditions: 1) polished with No.600 carbide paper, 2) air-abraded with alumina, 3) Alloy Primer metal conditioner was applied after alumina-abrasion, 4) Monobond Plus multipurpose conditioner was applied after alumina-abrasion, 5) M. L. Primer metal conditioner was applied after alumina-abrasion, and 6) Rocatec multipurpose silica-coating system was applied. The bond strengths were determined before and after thermocycling (50,000 cycles). The bond strengths of the alumina-abrasion group were significantly decreased after thermocycling. The Rocatec and M. L. Primer exhibited higher bond strengths than other treatments. The application of metal conditioners and multipurpose surface preparations was recommended for improved bonding between the evaluated adhesive resin and gold alloy.

Bonding durability between acrylic resin adhesives and titanium with surface preparations.

The purpose of the present study was to evaluate the efficacy of pretreatment on the bonding durability between titanium casting and two acrylic adhesives. Cast titanium disk specimens treated with four polymer-metal bonding systems as follow: 1) air-abraded with 50-70 µm alumina, 2) 1)+Alloy Primer, 3) 1)+M.L. Primer and 4) tribochemical silica/silane coating system (Rocatec System). The specimens were bonded with M bond or Super-bond C&B adhesive. The shear bond strengths were determined before and after thermocycling (20,000 cycles). The surface characteristics after polishing, and for the 1) and 4) preparations were determined. The bond strengths for all combinations significantly decreased after thermocycling. The combination of Super-bond C&B adhesive and 2) led to significantly higher bond strength than the other preparations after thermocycling. The maximum height of the profile parameters for the polishing group was lower than other preparations.

Effects of polymerization method on flexural and shear bond strengths of a fiber-reinforced composite resin.

This study investigated the effects of indirect composite polymerization on the postcuring mechanical properties of a fiber-reinforced composite. An indirect composite seated on glass fibers preimpregnated with polymerized monomer was polymerized by 1) photoirradiation using a halogen-fluorescent polymerizing unit for 5 min, 2) method 1 plus secondary heating at 100°C for 15 min, 3) photoirradiation using a metal halide light unit for 60 s, or 4) preliminary polymerization using a halogen light unit for 20 s followed by method 3. After polymerization, the flexural and shear bond strengths of the fiber-reinforced composite were examined, as was the flexural strength of non-fiber-reinforced composite specimens polymerized using the same methods. Among non-fiber-reinforced composite specimens, flexural strength was lower for method 1 than for the other three methods; however, among fiberreinforced composite specimens, the four methods did not significantly differ in flexural strength or shear bond strength. Composite-fiber interface separation without breakage of the fiber after flexural strength testing was not observed in specimens polymerized by methods 2 or 4. In conclusion, use of a conventional unit for high-intensity light irradiation after preliminary irradiation, or light irradiation followed by secondary heating, is recommended for polymerization of composite material seated on polymerized glass fiber.

Factors affecting the bond strength of denture base and reline acrylic resins to base metal materials.

OBJECTIVE: The shear bond strengths of two hard chairside reline resin materials and an auto-polymerizing denture base resin material to cast Ti and a Co-Cr alloy treated using four conditioning methods were investigated. MATERIAL AND METHODS: Disk specimens (diameter 10 mm and thickness 2.5 mm) were cast from pure Ti and Co-Cr alloy. The specimens were wet-ground to a final surface finish of 600 grit, air-dried, and treated with the following bonding systems: 1) air-abraded with 50-70-µm grain alumina (CON); 2) 1) + conditioned with a primer, including an acidic phosphonoacetate monomer (MHPA); 3) 1) + conditioned with a primer including a diphosphate monomer (MDP); 4) treated with a tribochemical system. Three resin materials were applied to each metal specimen. Shear bond strengths were determined before and after 10,000 thermocycles. RESULTS: The strengths decreased after thermocycling for all combinations. Among the resin materials assessed, the denture base material showed significantly (p<0.05) greater shear bond strengths than the two reline materials, except for the CON condition. After 10,000 thermocycles, the bond strengths of two reline materials decreased to less than 10 MPa for both metals. The bond strengths of the denture base material with MDP were sufficient: 34.56 MPa for cast Ti and 38.30 for Co-Cr alloy. CONCLUSION: Bonding of reline resin materials to metals assessed was clinically insufficient, regardless of metal type, surface treatment, and resin composition. For the relining of metal denture frameworks, a denture base material should be used.

Factors affecting the bond strength of denture base and reline acrylic resins to base metal materials

OBJECTIVE: The shear bond strengths of two hard chairside reline resin materials and an auto-polymerizing denture base resin material to cast Ti and a Co-Cr alloy treated using four conditioning methods were investigated. MATERIAL AND METHODS: Disk specimens (diameter 10 mm and thickness 2.5 mm) were cast from pure Ti and Co-Cr alloy. The specimens were wet-ground to a final surface finish of 600 grit, air-dried, and treated with the following bonding systems: 1) air-abraded with 50-70-µm grain alumina (CON); 2) 1) + conditioned with a primer, including an acidic phosphonoacetate monomer (MHPA); 3) 1) + conditioned with a primer including a diphosphate monomer (MDP); 4) treated with a tribochemical system. Three resin materials were applied to each metal specimen. Shear bond strengths were determined before and after 10,000 thermocycles. RESULTS: The strengths decreased after thermocycling for all combinations. Among the resin materials assessed, the denture base material showed significantly (p<0.05) greater shear bond strengths than the two reline materials, except for the CON condition. After 10,000 thermocycles, the bond strengths of two reline materials decreased to less than 10 MPa for both metals. The bond strengths of the denture base material with MDP were sufficient: 34.56 MPa for cast Ti and 38.30 for Co-Cr alloy. CONCLUSION: Bonding of reline resin materials to metals assessed was clinically insufficient, regardless of metal type, surface treatment, and resin composition. For the relining of metal denture frameworks, a denture base material ...

Evaluation of a newly developed polymethyl methacrylate powder for brush-dip technique.

PURPOSE: The aim of this study is to evaluate a newly developed polymethyl methacrylate (PMMA) powder. METHODS: The particle size distribution, surface area, and particle shape of both new and traditional powders were compared. The shear bond strength of the resin cement with the new powder to a silver-palladium-copper-gold alloy was determined and compared to that for a cement with the traditional powder. Also, the weight of mixture held by the brush at one time of both powders was also calculated and compared as an index of mixability. RESULTS: The surface area of the new powder was smaller than that of the traditional powder, while the particles size distributions were similar. The new powder included various-sized spherical particles as well as irregular particles, while the traditional powder consisted of only irregular particles. The new powder showed significantly higher mixability, although its bond strength was not significantly different from that of traditional powder. CONCLUSION: The results of this study show that the interminglement of spherical and irregular particles cannot influence the bond strength to the alloy but is helpful to improve the working properties.

Bond strength of poly(methyl methacrylate) denture base material to cast titanium and cobalt-chromium alloy.

PURPOSE: The shear bond strength of an auto-polymerizing poly(methyl methacrylate) denture base resin material to cast titanium and cobalt-chromium alloy treated with six conditioning methods was investigated. MATERIALS AND METHODS: Disk specimens (10 mm in diameter and 2.5 mm in thickness) were cast from pure titanium and cobalt-chromium alloy. The specimens were wet ground to a final surface finish of 600 grit, air dried, and treated with the following bonding systems: 1) air abraded with 50-70-microm-grain alumina (SAN); 2) air abraded with 50-70-microm-grain alumina + conditioned with Alloy Primer (ALP); 3) air abraded with 50-70-microm-grain alumina + conditioned with AZ Primer (AZP); 4) air abraded with 50-70-microm-grain alumina + conditioned with Estenia Opaque Primer (EOP); 5) air abraded with 50-70-microm-grain alumina + conditioned with Metal Link Primer (MLP), and 6) treated with ROCATEC system (ROC). A denture base material (Palapress Vario) was then applied to each metal specimen. Shear bond strengths were determined before and after 10,000 thermocycles. RESULTS: The strengths decreased after thermocycling in all combinations. Among the treatment methods assessed, groups 2 and 4 showed significantly (p < 0.05) enhanced shear bond strengths for both metals. In group 4, the strength in MPa (n = 7) after thermocycling for cobalt-chromium alloy was 38.3, which was statistically (p < 0.05) higher than that for cast titanium (34.7). CONCLUSION: Air abrasion followed by the application of two primers containing a hydrophobic phosphate monomer (MDP) effectively improved the strength of the bond of denture base material to cast titanium and cobalt-chromium alloy.

Evaluation of two dual-functional primers and a tribochemical surface modification system applied to the bonding of an indirect composite resin to metals.

We evaluated the effects of two dual-functional primers and a tribochemical surface modification system on the bond strength between an indirect composite resin and gold alloy or titanium. Disk specimens (diameter, 10 mm; thickness, 2.5 mm) were cast from type 4 gold alloy and commercially pure titanium. The specimens were wetground to a final surface finish using 600-grit silicone carbide paper. The specimens were then air-dried and treated using the following four bonding systems: (1) air-abrasion with 50-70 mum alumina, (2) system 1 + alloy primer, (3) system 1 + metal link primer, and (4) tribochemical silica/silane coating (Rocatec). A light-polymerizing indirect composite resin (Ceramage) was applied to each metal specimen and polymerized according to the manufacturer's specifications. Shear bond strengths (MPa) were determined both before and after thermocycling (4 degrees C and 60 degrees C for 1 min each for 20 000 cycles). The values were compared using analysis of variance, post hoc Scheffe tests, and Mann-Whitney U tests (alpha = 0.05). The strengths decreased after thermocycling for all combinations. For both gold alloy and titanium, the bond strength with air-abrasion only was statistically lower than that with the other three modification methods after thermocycling. Titanium exhibited a significantly higher value (13.4 MPa) than gold alloy (10.5 MPa) with the air. abrasion and alloy primer system. Treatment with the tribochemical system or air abrasion followed by treatment with dual-functional priming agents was found to be effective for enhancement of the bonding between the indirect composite and gold alloy or titanium.

Bond strength to primed Ti-6Al-7Nb alloy of two acrylic resin adhesives.

This study aimed to evaluate the bonding behavior of two acrylic resin adhesives joined to titanium-aluminum-niobium (Ti-6Al-7Nb) alloy primed with two metal conditioners. Cast Ti-6Al-7Nb alloy disks were air-abraded with alumina and bonded with six combinations of two resin adhesives (Super-Bond C&B and Multi Bond) and three surface conditions (Alloy Primer, M.L. Primer, and unprimed control). Shear bond strengths were determined both before and after 20,000 thermal cycles. The tri-n-butylborane initiated Super-Bond C and B resin exhibited greater bond strength than the BPO-amine initiated Multi-Bond resin. Both the Alloy Primer with a hydrophobic phosphate and the M.L. Primer with a phosphonoacetate effectively improved the 24-hour bond strength of Multi-Bond resin as well as the post-thermocycling bond strength of Super-Bond C and B resin.

Evaluation of 2 thione primers and 3 resin adhesives for silver-palladium-copper-gold alloy bonding.

OBJECTIVE: The purpose of this study was to evaluate 2 thione primers and 3 resin adhesives for enhancement of bonding strength to a silver-palladium-copper-gold alloy. METHOD AND MATERIALS: Two different sized disk specimens (10- and 8-mm diameter by 2.5-mm thick) were prepared from a silver-palladium-copper-gold alloy (Castwell M.C. 12, GC). The specimens were airborne-particle abraded with 50-microm-grain alumina, conditioned either with a thiouracil primer (Metaltite, Tokuyama Dental) or with a triazine dithione primer (V-Primer, Sun Medical), and then bonded with 1 of 3 acrylic resins: a benzoyl peroxide-amine redox-initiated resin adhesive (Multi-Bond, Tokuyama Dental) or a tri-nbutylborane-initiated resin adhesive (Super-Bond C&B and Super-Bond Quick, Sun Medical). For each adhesive, unprimed specimens were prepared as experimental controls. Shear bond strength was determined after thermocycling (100,000 cycles). RESULTS: Use of primers significantly (P < .05) enhanced the bond strength of specimens in all adhesives. Irrespective of the type of primer, the strength of Multi-Bond adhesive was significantly (P < .05) lower than that of Super-Bond C&B and Super-Bond Quick adhesives. The strength of the 2 tri-n-butylborane-initiated adhesives did not differ significantly (P > .05). The mean strength of the Super-Bond C&B adhesive was 40.4 MPa with Metaltite and 37.8 MPa with V-Primer; that of Super-Bond Quick adhesive was 40.9 MPa with Metaltite and 36.5 MPa with V-Primer. CONCLUSION: Use of thione primers effectively enhanced the strength of the bond to the silver-palladium-copper-gold alloy. Furthermore, the combinations of primers and tri-n-butylborane-initiated adhesives were found to be more efficient for bonding.

Influence of centrifugal force on filler loading of resin composites.

This study examined the influence of centrifugal force on the filler loading of composites using a light-polymerizing apparatus combined with a centrifuge. To assess uneven filler particle distribution resulting from specimen rotation, two low-viscosity composites (Palfique Estelite LV and Revolution Formula 2) were placed in test tubes, centrifuged, and subsequently light-polymerized with the apparatus. After each specimen was sliced into four disks (2-mm thickness), the inorganic filler content and Knoop hardness number (KHN) of each disk were determined. The results suggested that filler loading of composites could be increased by application of centrifugal force if the filler and monomer components were properly arranged.

Twenty-four hour bond strength between layers of a highly loaded indirect composite.

This study evaluated the repair bond strength of Estenia composite. Disk specimens of a dentin material were conditioned with varying combinations of silane primer (Add-on Primer, Clearfil Porcelain Bond Activator, Clearfil Porcelain Bond Activator + Clearfil Mega Bond-Primer, Porcelain Liner M, and unprimed) and bonding agent (Clearfil Mega Bond-Bond, Modeling Liquid, Stain Diluent, and no bonding agent). After photopolymerization of the enamel material placed on each surface, the specimens were either wet- or dry-stored at 37 degrees C for 24 hours. Average shear bond strength varied from 24.9 to 61.4 MPa, where the Clearfil Porcelain Bond Activator + Clearfil Mega Bond-Bond group and the Add-on Primer + Modeling Liquid group showed the greatest bond strength for dry and wet conditions respectively. To achieve reliable bond strength between layers of Estenia composite, it is highly recommended to use specific combinations of silane primer and bonding agent.

Effectiveness of bonding systems on bonding durability of a prefabricated porcelain material.

The purpose of the present study was to evaluate the bond strength and durability of four bonding systems joined to a prefabricated porcelain material (Vita Celay Blanks). Two sizes of porcelain block were bonded with one of the following systems: (1) Clapearl Bonding Agent and Clapearl DC; (2) Imperva Porcelain Primer and Imperva Dual; (3) Monobond S and Variolink II; or (4) Tokuso Ceramics Primer and Bistite II. Shear bond strength was measured after 24-hour immersion in water and after subsequent thermocycling. The average pre- and post-thermocycling bond strengths in MPa (n=8) were: 52.5 and 42.5 for bonding system (1), 47.7 and 32.8 for (2), 55.0 and 48.8 for (3), and 51.5 and 25.6 for (4). Although prethermocycling results were not statistically different from each other, Group (3) exhibited the greatest strength after thermocycling.

Color stability of acrylic resin adhesives with different initiation modes.

The purpose of this study was to evaluate the color stability of two acrylic resin adhesives with different activation systems: a benzoyl peroxide (BPO)-amine redox system and a tri-n-butylborane (TBB) derivative system. The colorimetric values of the two resins in different shades (Clear and Ivory) were determined (n=5) 24 hours after polymerization as a baseline using the L*a*b* system of the Commission Internationale de l'Eclairage (CIE). The specimens were thereafter immersed in distilled water, and the color difference (deltaE*) values were calculated. After 24 weeks, the TBB-initiated material showed a significantly (p<0.05) lower color change than the BPO-amine-initiated material. The deltaE* values for the BPO-amine-initiated materials were 6.9 for Clear and 15.8 for Ivory, whereas those for the TBB-initiated materials were 1.3 and 1.8 respectively. Thus, it was concluded that the TBB-initiated material had superior color stability to that of the BPO-amine-initiated material.

Effects of a fluoride etchant on resin bonding to titanium-aluminum-niobium alloy.

This investigation was carried out in order to evaluate ammonium hydrogen fluoride (AHF) and cupric chloride (CC) as components of a metal etchant. The surface of cast titanium-aluminum-niobium (Ti-6Al-7Nb) was air-abraded with alumina, etched for 10 s, and rinsed with water. A phosphate or a thiophosphate primer was applied to the bonding area, and an acrylic rod was bonded to the specimen with a tri-n-butylborane-initiated self-curing luting agent. Shear bond strengths were determined after thermocycling (4 degrees C and 60 degrees C) for 10,000 cycles. The average bond strength was significantly influenced by thermocycling, AHF, and primer, but was not influenced by CC. The maximum average bond strengths were obtained when the etchant consisted of 5mass% AHF, with and without 0.3mass% CC. Microphotographs showed that numerous micropits were created on the etched surface, suggesting increased micromechanical retention. In conclusion, chemical etching with 5mass% AHF significantly improved the durability of resin bonding to Ti-6Al-7Nb.

Effects of a metal etchant and two primers on resin bonding durability to titanium.

The purpose of this study was to investigate the efficacy of an etchant in titanium bonding. The aqueous etchant consisted of 0, 5, or 10 wt% ammonium hydrogen fluoride (AHF) in combination with 0, 0.03, 0.3, or 3 wt% cupric chloride (CC). The two primers used were a phosphate-methacrylate primer and a thiophosphate-methacrylate primer, and two self-curing resins (Super-Bond C&B and MT) were employed as luting agents. Disk specimens were cast with a commercially pure titanium. The surface was air-abraded with 50 microm alumina, etched for 10 s, rinsed with water, and then air-dried. The primer was applied to the bonding area (5 mm in diameter), and an acrylic rod was bonded to the specimen with the luting agent. Shear bond strengths were evaluated after 24 h of water storage and following 10,000 thermocycles (4 degrees C and 60 degrees C). The post-thermocycling bond strength was significantly increased with each of the two primers compared with the unprimed controls. The etchant containing 5 wt% AHF and 0.3 wt% CC further increased their durability, and microscopic observation revealed that innumerable submicron crystals were created on the etched specimen. The present results suggest that the chemical etching improved the resin bonding durability to titanium in combination with the primer used.

Adhesive bonding of titanium-aluminum-niobium alloy with nine surface preparations and three self-curing resins.

The purpose of the current study was to evaluate the adhesive performance of metal conditioners when used for bonding between auto-polymerizing methacrylic resins and a titanium alloy. Disk specimens were cast from a titanium-aluminum-niobium (Ti-6Al-7Nb) alloy, air-abraded with alumina, and bonded with 24 combinations of eight metal conditioners (Acryl Bond, ACB; All-Bond 2 Primer B, ABB; Alloy Primer, ALP; Cesead II Opaque Primer, COP; Metafast Bonding Liner, MBL; Metal Primer II, MPII; MR Bond, MRB; Super-Bond liquid, SBL) and three autopolymerizing methacrylic resins (Repairsin, RE; Super-Bond C & B, SB; Tokuso Rebase; TR). Unprimed specimens were used as controls. Shear bond strengths were determined both before and after thermocycling (4-60 degrees C, 20, 000 cycles). The ALP-SB group recorded the greatest post-thermocycling bond strength (21.8 MPa) followed by the COP-SB group (17.8 MPa) and the MPII-SB group. The post-thermocycling bond strengths of the unprimed-SB group and the ALP-RE group were statistically comparable. No significant differences were found among the nine TR resin groups, and these groups showed the lowest bond strength. In conclusion, the use of one of the three conditioners (ALP, COP, and MPII) in combination with the SB resin is recommended for bonding the Ti-6Al-7Nb alloy.