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


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).


CONCLUSIONS
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.
Department of Applied Prosthodontics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
Yasuhiro
Y
Matsuda
Hiroaki
H
Yanagida
Takako
T
Ide
Hideo
H
Matsumura
Naomi
N
Tanoue
D000180:Acrylic Resins / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis; D003819:Denture Bases; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D010316:Particle Size; D010746:Phosphonoacetic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013871:Thiones / Q000737:chemistry; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
C546895:6-methacryloyloxyhexyl phosphonoacetate; D000180:Acrylic Resins; C521707:Alloy Primer; D002858:Chromium Alloys; D003738:Dental Cements; D003764:Dental Materials; C521708:Estenia Opaque Primer; D008689:Methacrylates; C507521:Palapress Vario; C076811:Rocatec; D013871:Thiones; C100646:Metal Primer; C069749:methacryloyloxydecyl dihydrogen phosphate; D019904:Polymethyl Methacrylate; D014025:Titanium; D000537:Aluminum Oxide; D010746:Phosphonoacetic Acid