Effects of resinous monomers used in restorative dental modeling on the cohesive strength of composite resin.
OBJECTIVE
The purpose of this study was to evaluate the cohesive strength of the composite using different resinous monomers to lubricate instruments used in the Restorative Dental Modeling Insertion Technique (RDMIT).


METHODS
The composite specimens were made by usinga prefabricated Teflon device. Different resinous monomers were used at the interface to lubricate the instruments, for a total of 72 specimens divided into 6 groups: (1) control group, no resinous monomer was used; (2) Composite Wetting Resin; (3) C & B Liquid; (4) Scotchbond Multi-Purpose Adhesive; (5) Adper Single Bond Adhesive; (6) Prime & Bond NT. Specimens were submitted to the circular area tensile test to evaluate the cohesive strength at the composite interfaces. Data were analyzed using ANOVA and Tukey's test (alpha = 0.05).


RESULTS
ANOVA showed a value of p < 0.0001, which indicated thatthere were significant differences amongthe groups. The means (SD) for the different groups were: Adper Single Bond Adhesive: 26 (12) a; control group: 28 (3) ab; Prime & Bond NT: 32 (12) ab; Composite Wetting Resin: 36 (9) abc; C&B Liquid: 38 (7) bc; Scotchbond Multi-Purpose Adhesive: 46 (10) c. Groups denoted with the same letters were not significantly different. Only Scotchbond Multi-Purpose Adhesive, used for direct restorations, had a statistically significantly higher bond strength than the control group, Adper Single Bond Adhesive, and Prime & Bond NT. Adper Single Bond with Adhesive showed a statistically significantly lower mean value than C & B Liquid.


CONCLUSIONS
The results of this study indicate that the resinous monomers used for lubricating the instruments in the RDMIT did not alter the mechanical properties of the composite, and therefore did not reduce the cohesive bond strength at the composite interfaces.
Barcellos
Daphne Camara
DC
Department of Restorative Dentistry and Endodontics, School of Dentistry, Sao Jose of Campos, State University Julio of Mesquita Filho, SP, Brazil.
Pucci
Cesar Rogerio
CR
Torres
Carlos Rocha Gomes
CR
Goto
Edson Hidenobu
EH
Inocencio
Aline Cassia
AC
D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003793:Dental Restoration, Permanent / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008153:Lubrication; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
D001896:Boron Compounds; D003188:Composite Resins; D008689:Methacrylates; D008768:Methylmethacrylates; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D019279:Resin Cements; C425844:Scotchbond Multi-Purpose Plus; C115612:single bond; D014867:Water; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C049495:Super-bond