A comparative study of the bond strengths of amalgam and alloy-glass ionomer cores.
The purpose of this study was to compare the bond strengths of dental amalgam cores and dental alloy-glass ionomer cores that were luted to cast gold crowns with glass ionomer cement. Seventy-two human extracted molars were sectioned horizontally and four regular thread mate system pins were inserted into a flat pulpal floor. The teeth were restored with amalgam or alloy-glass ionomer admixture and prepared for crown preparations. Castings were produced with type III gold and cemented to the cores with Fuji type I glass ionomer cement. Thirty-six of the specimens were subjected to thermal fatigue by cycling between 4 and 50 degrees C for periods of 1, 5 and 10 weeks. The remainder of the specimens were retained in deionized water at 37 degrees C. Bond strengths of the cores, in tension, were measured with a universal testing machine. The alloy-glass ionomer cores exhibited higher bond strengths than the amalgam cores for virtually all time periods, particularly the thermocycled samples. The alloy-glass ionomer cores exclusively displayed core fractures and pin/tooth insufficiencies while the amalgam cores failed because of a deterioration of the glass ionomer luting cement.
Arcoria
C J
CJ
Department of Operative Dentistry, Baylor College of Dentistry, Dallas, Texas 75246.
DeWald
J P
JP
Moody
C R
CR
Ferracane
J L
JL
D003442:Crowns; D003722:Dental Alloys; D003723:Dental Amalgam; D001840:Dental Bonding; D003738:Dental Cements; D003781:Denture Retention; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique; D013314:Stress, Mechanical
D003722:Dental Alloys; D003738:Dental Cements; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D003723:Dental Amalgam