Metal chloride primers for bonding dentine with tri-n-butylborane-initiated luting agents.
OBJECTIVE
The bonding of resin to dentine is dependent largely on surface modifications. The purpose of the present study was to test the hypothesis that a role of the metal chlorides used as primers is to initiate polymerization of resin at the resin-dentine interface, thereby affecting bond strength.


METHODS
Nine primers were evaluated, comprising aqueous 2-hydroxyethyl methacrylate (HEMA) solutions containing AICl3, CeCl3, CoCl2, CuCl2, FeCl3, NiCl2, MgCl2, SnCl2 or ZnCl2, respectively. One of the two luting agents (Super-Bond resin) consisted of methyl methacrylate (MMA), 4-methacryloyloxyethyl trimellitate anhydride (4-META) and tri-n-butylborane (TBB) initiator. The other luting agent (MMA-TBB resin) consisted of MMA and TBB without 4-META. Extracted bovine teeth were ground to expose the dentine, etched with an aqueous solution of 10% phosphoric acid, primed, and then bonded with stainless-steel rods; tensile bond strengths were determined after 1-day immersion in water. Data were analysed by ANOVA and Duncan's new multiple range test (P < 0.05).


RESULTS
Four of the metal chlorides (CuCl2, FeCl3, MgCl2 and ZnCl2) enhanced the bond strengths of MMA-TBB resin to dentine. With Super-Bond resin, maximum bond strengths of 15.6 MPa and 19.0 MPa were recorded with primer containing 2.0 x 10(-5) mol g(-1) FeCl3 and 2.0 x 10(-6) mol g(-1) CuCl2, respectively.


CONCLUSIONS
Bonding techniques, combining the use of either cupric primer or ferric primer with 10% phosphoric acid etchant may be suitable for application in seating resin-bonded prostheses with TBB-initiated luting materials.
Taira
Y
Y
Department of Fixed Prosthodontics, Nagasaki University School of Dentistry, Sakamoto, Japan.
Matsumura
H
H
Yoshida
K
K
Kamada
K
K
Tanaka
T
T
Atsuta
M
M
D000134:Acid Etching, Dental; D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000737:chemistry; D000704:Analysis of Variance; D000818:Animals; D001896:Boron Compounds / Q000737:chemistry*; D002417:Cattle; D002586:Cesium / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry; D007101:Immersion; D015636:Magnesium Chloride / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D020366:Methylmethacrylate / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry; D009532:Nickel / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties; D013718:Tensile Strength; D017971:Tin Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
D017607:Aluminum Compounds; D001896:Boron Compounds; D002712:Chlorides; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D005290:Ferric Compounds; D008670:Metals; D008689:Methacrylates; D008768:Methylmethacrylates; D010756:Phosphoric Acids; D011108:Polymers; D017971:Tin Compounds; D017967:Zinc Compounds; D015636:Magnesium Chloride; D014867:Water; C009523:tri-n-butylborane; D013193:Stainless Steel; D020366:Methylmethacrylate; C023599:stannous chloride; D002586:Cesium; D000077410:Aluminum Chloride; D003035:Cobalt; C022838:nickel chloride; C005044:hydroxyethyl methacrylate; C034139:4-methacryloxyethyltrimellitic acid anhydride; D003300:Copper; D009532:Nickel; C016837:zinc chloride; C049495:Super-bond; C018021:cobaltous chloride; C028019:cesium chloride; C029892:cupric chloride; C024555:ferric chloride