Yohsuke Taira

Effect of adhesive primers on bonding a prosthetic composite resin to metals

Abstract The effect of three adhesive metal primers on the shear bond strength of a light-cured prosthetic composite resin bonded to cobalt-chromium or silver-palladium-copper-gold casting alloy was evaluated. The adhesive metal primers used were New Metacolor opaque bonding liner, Cesead opaque primer, and 0.5% VBATDT in acetone. A newly prepared light-cured opaque resin was used to bond a light-cured veneering resin to dental alloys. The specimens were thermocycled in water for up to 20,000 cycles between 4 °C and 60 °C, and shear bond strengths were recorded. The light-cured composite resin bonded most strongly to Co-Cr alloy primed with Cesead primer and to Ag-Pd-Cu-Au alloy with the VBATDT primer. These adhesive metal primers may be clinically acceptable for bonding a light-cured prosthetic composite resin to base or precious metal.

Influence of surface oxidation of titanium on adhesion

OBJECTIVES The adhesive bonding of titanium was investigated using a methacrylate-phosphate primer and a luting agent. The present study investigates the influence of heat oxidation as well as a suitable durable bonding method for treating the surface of titanium. METHODS Two groups of disc specimens were fabricated by milling and casting, respectively. Machine-milled specimens were subjected to heat treatment, and three groups of cast metal specimens underwent following respective treatments: (1) as-cast, (2) emery-polishing, (3) alumina-blasting after emery-polishing. The primer contained 10-methacryloyloxydecyl dihydrogen phosphate (MDP); the luting agent was based on methyl methacrylate (MMA), and was initiated with tri-n-butylborane derivative (TBB). Each specimen was primed and bonded to an acrylic rod. Shear bond strengths were determined before and after thermocycling. RESULTS The mean bond strength of the machine-milled emery-polished group was 32.5 MPa after 5000 thermocycles with only a slight decrease in bond strength. A decrease in the bond strength occurred when the heat-treatment temperature was above 400 degrees C. Although both emery-polishing and alumina-blasting were effective, the minimum decrease in bond strength was obtained with alumina-blasting. CONCLUSIONS The excess surface oxide layer may be of great concern as a possible cause of decreased bonding durability. Sufficient bonding durability for clinical use was obtained when the titanium was alumina-blasted.

Primer for bonding resin to metal.

OBJECTIVES The purpose was to examine the effect on the bond strength and durability of a resin bond to metal of modification of a primer consisting of thiophosphoric methacrylate with phosphoric methacrylates and/or benzoyl peroxide. METHODS Acrylic rods were bonded with a luting resin consisting of poly(methyl methacrylate) powder and a mixture of methyl methacrylate and tributylborane initiator to silver-palladium alloy (Ag-Pd), gold-silver alloy (Au-Ag), cobalt-chromium alloy (Co-Cr), and titanium (Ti) surfaces treated with various primers. The bonded samples were thermocycled for 2,000 cycles and the mean bond strengths were compared using one-way ANOVA and Duncans new multiple range test at p < 0.05. RESULTS Using primers of thiophosphoric methacrylate or phosphoric methacrylates alone, the bond strengths of Ag-Pd decreased significantly (p < 0.05) after thermocycling. The durability was significantly improved (p < 0.05) when thiophosphoric methocrylate was used in combination with the phosphate monomers. The additional use of benzoyl peroxide and heat treatment resulted in a significant increase (p < 0.05) in the durability of two groups; the mean bond strengths over 20 MPa and the lowest values remained unchanged even after 2,000 thermocycles. SIGNIFICANCE The highest level of bond strength and durability to dental noble metals was achieved using a mixture of thiophosphoric and phosphoric methacrylates and benzoyl peroxide. These bond strength results are comparable to values obtained for base metals.

Phosphate and thiophosphate primers for bonding prosthodontic luting materials to titanium

STATEMENT OF PROBLEM When resin-bonded prostheses are constructed with titanium, they must be strongly bonded with luting materials for the prostheses to withstand the oral environment over the long term. However, limited information is available about the bond durability between luting materials and titanium. PURPOSE This study determined whether a phosphate and two thiophosphate primers increase bond strength and durability between a commercially available pure titanium and four luting agents. MATERIAL AND METHODS Three primers and four luting agents were divided into three groups according to the type of acidic monomers: carboxylic acid derivatives (4-META, 4-AET, and MAC10), a phosphoric acid derivative (MDP), and a thiophosphoric acid derivative (MEPS). Disk specimens were bonded with 16 combinations of 3 primers and 4 luting agents, including 4 controls. Shear bond strengths were determined after 1-day immersion in water and after thermocycling for 100,000 cycles. RESULTS Bond strengths were influenced by thermocycling, primer, luting agent, and their combinations. After thermocycling, the groups that demonstrated the highest bond strengths were six combinations of two primers (Cesead Opaque Primer and Metal Primer II) and three luting agents (Imperva Dual, Panavia 21, and Super-Bond C&B).

Effects of adhesive primers on bond strength of self-curing resin to cobalt- chromium alloy

PURPOSE This study evaluated the effects of four adhesive primers on the shear bond strength of a self curing resin to cobalt-chromium alloy. MATERIAL AND METHODS The adhesive primers Acryl Bond (AB), Cesead Opaque Primer (COP), Metal Primer II (MPII), and MR Bond (MRB) were used. A brass ring placed over the casting alloy disk surface nonprimed or primed with each primer was filled with the self-curing methyl methacrylate polymethyl methacrylate resin. The specimens were stored in water at 37 degrees C for 24 hours and then alternately immersed in water baths at 4 degrees C and 60 degrees C for 1 minute each for up to 20,000 thermal cycles before shear mode testing at a crosshead speed of 0.5 mm/min. RESULTS All the primers examined improved the shear bond strength between the resin and cobalt chromium alloy compared with nonprimed specimens before thermal cycling. However, after 20,000 thermal cycles, the bond strengths of resin to cobalt chromium alloy primed with COP or MPII primers were significantly greater than those of specimens primed with AB or MRB primers and nonprimed controls. CONCLUSION This study indicated that COP and MPII are effective primers to obtain higher bond strength between resin and cobalt-chromium alloy.

Bonding of a cobalt-chromium alloy with acidic primers and tri-n-butylborane-initiated luting agents

Limited information is available about chemical bonding of cobalt-chromium alloys for resin-retained fixed partial dentures. This study evaluated the effect of acidic primers on the bonding of luting agents joined to a cobalt-chromium alloy. Disk alloy specimens were bonded with eight combinations of five primers and two luting agents. Shear bond strengths were determined before and after thermocycling. The effect of priming on bond strength varied among the combinations of primer and luting agent. In particular, after thermocycling three groups demonstrated greater bond strengths than the other groups did. These were (1) specimens treated with a phosphate-methacrylate primer (Cesead Opaque Primer), (2) specimens bonded with an adhesive resin (Super-Bond Opaque), or (3) a combination of both.

Effects of primers containing sulfur and phosphate monomers on bonding type IV gold alloy.

OBJECTIVE The purpose of the present study was to evaluate the effect of five primers (two sulfur, one phosphate, and two sulfur-phosphate dual-function primers) on the bond strength between a self-curing luting agent and gold-copper-silver (Au-Cu-Ag) alloy. METHODS The primers used were two sulfur primers (V-Primer and Metaltite), one phosphate primer (Epricord), and two primers which contained a sulfur monomer and a phosphate monomer (Alloy Primer and Metaltite/Epricord). The surface of Au-Cu-Ag specimens were blasted with alumina, and then bonded with acrylic rods using a tri-n-butylborane-initiated self-curing luting agent. Shear bond strengths were determined after 5000 thermocycles. An additional alumina-blasted Au-Cu-Ag alloy specimen was subjected to X-ray photoelectron spectroscopy (XPS) analysis. RESULTS The maximum shear bond strengths were obtained with Metaltite/Epricord (29.6+/-2.3 MPa) and Alloy Primer (23.0+/-1.6 MPa), followed by Metaltite (10.3+/-4.2 MPa), V-Primer (8.9+/-0.6 MPa), Epricord (6.4+/-1.5 MPa), and No primer control (2.0+/-0.5 MPa). The XPS analysis detected six chemical elements (Au, Cu, Ag, Al, O, and C) on the Au-Cu-Ag alloy. In addition to pure Au element, the metal oxide-states of Ag2O, AgO, Cu2O, and CuO were suggested. CONCLUSION The combined use of a sulfur monomer and a phosphate monomer significantly improved the bond strength of resin to Au-Cu-Ag alloy which should be especially significant to clinicians.

Effects of primer containing silane and thiophosphate monomers on bonding resin to a leucite-reinforced ceramic

OBJECTIVES Silane primers are commonly used for bonding between resin-based luting agents and ceramic restorations. The purpose of the present study was to evaluate the effects of nine silane primers on the bond strength of resin to a leucite-reinforced ceramic. METHODS The commercially available dental primers used were five silane primers (GC Ceramic Primer, GP; Clearfil Ceramic Primer, CP; Tokuso Ceramic Primer, TP; Porcelain Liner M, PM; and Monobond Plus, MB). Four experimental primers (MDS, MTS, MDS/MPII, and MTS/MPII) and two control primers (MMA and MMA/MPII) were also prepared. The ceramic specimen was ground with silicon carbide paper, primed, and then bonded to a resin composite disc using a dual-curing luting agent. After a 24-h immersion in water, the shear bond strengths were determined. RESULTS Shear bond testing revealed that the bond strength was significantly improved with the use of a MTS/MPII primer when compared to MDS, MTS, MMA, MDS/MPII and MMA/MPII. Although no significant differences were detected between GP, CP, PM, and MB, the primers CP, TP, PM, and MTS/MPII exhibited the highest bond strengths, followed by GP and MB, whilst the no-primer control resulted in the lowest values. CONCLUSION The maximum bond strengths were obtained with CP, TP, PM, and MTS/MPII. It was suggested that the thiophosphate monomer accelerated the role of the silane monomer. When selecting a primer to bond ceramic restorations, clinicians should be aware that not only the silane monomer but also additional components of the primer considerably affect the bond strength.

Silane primers rather than heat treatment contribute to adhesive bonding between tri-n-butylborane resin and a machinable leucite-reinforced ceramic

The purpose of the present study was to evaluate the effects of silane primers with and without heat treatment on bonding between a resin and a leucite-reinforced ceramic (GN-Ceram). Six dental primers (GC Ceramic Primer, GP; Clearfil Ceramic Primer, CP; RelyX Ceramic Primer, RP; Tokuso Ceramic Primer, TP; Shofu Porcelain Primer, SP; and Porcelain Liner M, PM) and five experimental primers (MDS, MTS, MDES, MTES, and ATS) were evaluated. GN-Ceram specimen was primed, heated at 100°C for 60 min (Heat), and then bonded to a resin composite using a self-curing resin. Shear bond testing revealed that GP, GP/Heat, CP, CP/Heat, RP, RP/Heat, TP, TP/Heat, SP, SP/Heat, PM, PM/Heat, MDS/Heat, MTS, MTS/Heat, and ATS/Heat exhibited superior bond strengths. No-primer, No-primer/Heat, MDS, MDES, MTES, and ATS exhibited low bond strengths, while there were no significant differences in bond strength among SP, MDS, MDES/Heat, and MTES/Heat. It seemed that heat treatment improved the bonding performance for MDS, MTES, and ATS only.

Effect of ultrasonic instrumentation on bond strength of three dental cements bonded to nickel-chromium alloy.

This study examined the effect of ultrasonic instrumentation on the bond strength of three types of luting material joined to a nickel-chromium alloy. Disk metal specimens were bonded together with zinc phosphate, glass ionomer, and adhesive resin luting agents. The bonded specimens were immersed in water, then vibrated with an ultrasonic unit for 0 to 5 minutes. The shear bond strength in the 0 or nonvibrated group was 50.1 MPa for adhesive resin, 18.4 MPa for glass ionomer, and 4.7 MPa for zinc phosphate cement. Vibration for a period of 5 minutes significantly diminished the bond strength of adhesive resin and glass ionomer materials, whereas the bond strength of zinc phosphate cement was affected after only 1 minute.