Tensile bond strength of an adhesive resin cement to different alloys having various surface treatments.
BACKGROUND
The ability of a resin cement to bond to a restorative alloy is critical for maximal crown retention to nonideal preparations. Surface treatment and metal type may have an important role in optimizing resin-to-metal strength.


OBJECTIVE
The purpose of this study was to examine the effect of surface pretreatment on the tensile strength of base and noble metals bonded using a conventional resin cement.


METHODS
Cylindrical plastic rods (9.5 mm in diameter), cast in base (Rexillium NBF) or noble metal (IPS d.SIGN 53), were divided into rods 10 mm in length (n=10-12). Specimens were heated in a porcelain furnace to create an oxide layer. Test specimens were further subjected to airborne-particle abrasion (50-microm Al(2)O(3) particles) alone or with the application of a metal primer (Alloy Primer). Similarly treated rod ends were joined using resin cement (RelyX ARC), thermocycled (x500, 5 degrees -55 degrees C) and stored (24 hours, 37 degrees C) before debonding using a universal testing machine. Debond strength and failure site were recorded. Rank-based ANOVA for unbalanced designs was used to test for significant interaction (alpha=.050). Each pair of treatments was compared separately for each metal (Bonferroni-adjusted significance level of .0083, overall error rate for comparisons, .05). The 2 metals were compared separately for each of the 3 treatments using an adjusted significance level of .017, maintaining an overall error rate of .05. A multinomial logit model was used to describe the effect of metal type and surface pretreatment on failure site location (alpha=.05).


RESULTS
Interaction between metal type and surface pretreatment was significant for stress values (P=.019). Metal type did not significantly affect tensile bond strength for any of the compared surface pretreatments. Metal primer significantly improved tensile bond strength for each metal type. Most failures tended to occur as either adhesive or mixed in nature.


CONCLUSIONS
Metal primer application significantly enhanced tensile bond strength to base and noble metal. No significant differences in tensile strength were found between alloys. Differences in failure site incidence were found to be related to metal type and surface pretreatment.
Abreu
Amara
A
Department of Oral Rehabilitation, School of Dentistry, Medical College of Georgia, Augusta, GA 30912, USA. aabreu@mcg.edu
Loza
Maria A
MA
Elias
Augusto
A
Mukhopadhyay
Siuli
S
Looney
Stephen
S
Rueggeberg
Frederick A
FA
D020906:Air Abrasion, Dental; D017438:Bisphenol A-Glycidyl Methacrylate; D002858:Chromium Alloys; D003442:Crowns; D003722:Dental Alloys; D001840:Dental Bonding; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D016015:Logistic Models; D016876:Metal Ceramic Alloys; D008689:Methacrylates; D010087:Oxides; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D019279:Resin Cements; D013499:Surface Properties; D013718:Tensile Strength; D013871:Thiones
C521707:Alloy Primer; D002858:Chromium Alloys; D003722:Dental Alloys; D016876:Metal Ceramic Alloys; D008689:Methacrylates; D010087:Oxides; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; D013871:Thiones; C051993:palladium-silver alloy W1; D003776:Dental Porcelain; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate