Analysis of the diametral compressive bond strength between composite resin and amalgam in different stages of oxidation.
OBJECTIVE
Amalcomp is a technique that combines composite resin to amalgam in restorative procedures to improve esthetics and minimize the negative effects of polymerization on dental tissues. The objective of this in vitro study was to measure the diametral compressive bond strength between Fill Magic composite (Vigodent) versus Permite (DFL) or Velvalloy (SS White) amalgams in different oxidation stages.


METHODS
Twenty-four cylinders of each amalgam brand were fabricated using a Teflon matrix and divided into 3 groups according to the immersion period in artificial saliva for oxidation: A (1 day), B (7 days) and C (30 days). After immersion, the amalgam cylinders were bonded to the composite specimens using the Scotch Bond Multi Use Plus (3M) bonding system. Diametral compression assays were then carried out in an EMIC-MEM 2000 universal testing machine set to 0.5 mm/min. Statistical analysis was performed using ANOVA and Tukey's test.


RESULTS
The mean recorded strength (MPa) for each oxidation group was: A=9.71, B=8.21 and C=6.98 (A>B = C; P<0.01). Permite (7.24) provided significantly less adhesion to the composite than Velvalloy (9.36; P<0.05). There was no interaction between the factors alloy, resin and time.


CONCLUSIONS
Under the conditions of this study, the less oxidized amalgam showed the greatest diametral compressive strength values.
Benitez Catirse
A B E
AB
Dental Materials Unit, Ribeirão Preto College of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
Oliveira Pagnano
V
V
Da Silva Mello
A S
AS
Do Nascimento
C
C
Mardegan Issa
J P
JP
D003188:Composite Resins / Q000737:chemistry*; D019245:Compressive Strength; D003300:Copper / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D003723:Dental Amalgam / Q000737:chemistry*; D001840:Dental Bonding; D008422:Materials Testing; D010084:Oxidation-Reduction; D012464:Saliva, Artificial / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013997:Time Factors
D003188:Composite Resins; D003722:Dental Alloys; C481898:Fill Magic; D012464:Saliva, Artificial; C075189:Velvalloy; D012834:Silver; D003300:Copper; D003723:Dental Amalgam; C092423:Permite C