Effect of silica coating on fracture strength of glass-infiltrated alumina ceramic cemented to dentin.
OBJECTIVE
To examine the availability of sol-gel processed silica coating for alumina-based ceramic bonding, and determine which silica sol concentration was appropriate for silica coating.


METHODS
Sixty disks of In-Ceram alumina ceramic were fabricated and randomly divided into 5 main groups. The disks received 5 different surface conditioning treatments: Group Al, sandblasted; Group AlC, sandblasted + silane coupling agent applied; Groups Al20C, Al30C, and Al40C, sandblasted, silica coating via sol-gel process prepared using 20 wt%, 30 wt%, and 40 wt% silica sols, and then silane coupling agent applied. Before bonding, one-step adhesives were applied on pre-prepared ceramic surfaces of all groups. Then, 60 dentin specimens were prepared and conditioned with phosphoric acid and one-step adhesive. Ceramic disks of all groups were cemented to dentin specimens with dual-curing resin cements. Fracture strength was determined at 24 h and after 20 days of storage in water.


RESULTS
Groups Al20C, Al30C, and Al40C revealed significantly higher fracture strength than groups Al and AlC. No statistically significant difference in fracture strength was found between groups Al and AlC, or among groups Al20C, Al30C, and Al40C. Fracture strength values of all the groups did not change after 20 days of water storage.


CONCLUSIONS
Sol-gel processed silica coating can enhance fracture strength of In-Ceram alumina ceramic after bonding to dentin, and different silica sol concentrations produced the same effects. Twenty days of water storage did not decrease the fracture strength.
Department of Prosthodontics, Nanjing Medical University, Nanjing, China,
Haifeng
H
Xie
Ye
Y
Zhu
Chen
C
Chen
Ning
N
Gu
Feimin
F
Zhang
D000134:Acid Etching, Dental / Q000379:methods; D000537:Aluminum Oxide / Q000737:chemistry*; D002484:Cementation / Q000379:methods*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D044367:Phase Transition; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D055116:Self-Curing of Dental Resins; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; C086628:Choice resin cement; D020099:Coated Materials, Biocompatible; D017220:Dentin-Bonding Agents; C483026:In-Ceram Alumina; D008689:Methacrylates; D010756:Phosphoric Acids; D019279:Resin Cements; D012821:Silanes; D014867:Water; D003776:Dental Porcelain; D012822:Silicon Dioxide; C030242:phosphoric acid; D000537:Aluminum Oxide