Adhesive bonding of resin composite to various Ni-Cr alloy surfaces using different metal conditioners and a surface modification system.
OBJECTIVE
This study evaluated the effect of three metal conditioners [Metal Photo Primer (MPP), Cesead II Opaque Primer (OP), Targis Link (TL)], and one surface modification system [Siloc (S)] on the shear bond strength (SBS) of a prosthetic composite material to Ni-Cr alloy.


METHODS
Rivet-shaped specimens were cast, and three surface treatments were evaluated: Polishing (P); sandblasting with either 50 microm (50SB) or 250 microm (250SB) Al(2)O(3). All products were applied to half of the specimens, while the other half remained without the materials. Veneering resin composite (8-mm diameter, 2-mm thick) was applied and light-exposed for 90 seconds in a laboratory light-curing unit. The specimens were stored in water at 37 degrees C for 24 hours, and half were subjected to 500 thermal cycles consisting of water baths at 4 degrees C and 60 degrees C. All specimens were submitted to SBS test (0.5 mm/min) until failure. Failure patterns were determined using optical and scanning electron microscope (SEM) analysis. Data were analyzed by ANOVA and post hoc Tukey's test (preset alpha of 5%).


RESULTS
The SBS values of OP and TL groups were higher than those of MPP and S within the 50SB treatment (p < 0.05). No significant difference in SBS was noted between OP and TL as well as between MPP and S. On the other hand, no significant differences were found among conditioners within the 250SB group (p > 0.05). The SBS values of MPP, OP, and S from the 250SB group were higher than those from 50SB (p < 0.05). No significant difference in SBS was noted among most groups with conditioners after thermocycling. The only exception was observed for MPP, which showed an increase in SBS after thermocycling (p < 0.05). Differences in SBS were noted among the groups with conditioners (p < 0.05), and no significant difference in SBS was noted between TL and OP groups, which showed the highest values among all within the P group. No significant difference was noted between MPP and S. Debonded surfaces showed adhesive failures predominantly located between metal surface and opaque resin.


CONCLUSIONS
The OP and TL conditioners and surface sandblasting with 250 microm Al(2)O(3) promoted the highest SBS between resin and the Ni-Cr metal surface.
Almilhatti
Hercules Jorge
HJ
Department of Restorative Dentistry, Federal University of Paraná, UFPR, Curitiba, Brazil. almilhatti@ufpr.br
Giampaolo
Eunice Teresinha
ET
Vergani
Carlos Eduardo
CE
Machado
Ana Lucia
AL
Pavarina
Ana Claudia
AC
Betiol
Ederson Aureo Goncalves
EA
D000179:Acrylates / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D045662:Dental Etching / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D003801:Dental Veneers; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012821:Silanes / Q000737:chemistry; D012823:Silicate Cement / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014233:Tricarboxylic Acids / Q000737:chemistry; D014867:Water / Q000737:chemistry
C546896:4-acryloyloxyethyltrimellitic acid; D000179:Acrylates; D017554:Carbon Compounds, Inorganic; D002858:Chromium Alloys; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D005899:Glass Ionomer Cements; D008689:Methacrylates; D019279:Resin Cements; D012821:Silanes; D017655:Silicon Compounds; C465121:Siloc; D014233:Tricarboxylic Acids; C111282:dental polyglass; D014867:Water; D012823:Silicate Cement; C100646:Metal Primer; C017492:methacryloxypropyltrimethoxysilane; D009532:Nickel; C069749:methacryloyloxydecyl dihydrogen phosphate; D000537:Aluminum Oxide; C022088:silicon carbide