Depth and distribution of the cure in a resin-based composite cured in a simulated Class II cavity.
OBJECTIVE
To examine the effect that a stainless steel (SS) matrix band has on the depth and distribution of cure of a resin-based composite (RBC) in a simulated Class II cavity.


METHODS
RBC was cured for 20 seconds in a simulated Class II cavity with and without a SS matrix band, and after 24 hours the specimens were scraped back and ground to expose a vertical central plane where Knoop micro-hardness (KHN) mapping was conducted from 0.05-1.5 mm from the band and in 0.5 mm intervals from the top of the specimens. The effect of different angles of the light guide on the distribution of hardness was also examined.


RESULTS
KHN values near the SS matrix band were significantly lower (P < 0.05) than within the bulk of the specimen and were lower than those found without the matrix band. Angles of incidence for the curing light-guide produced changes in the distribution of KHN within the specimens, but particularly near the matrix band, and with a 35° angle of incidence, the depth of cure was significantly different from that of normal incidence of the light.
Robert L
RL
Erickson
Wayne W
WW
Barkmeier
D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental / Q000145:classification; D003722:Dental Alloys / Q000737:chemistry; D003737:Dental Cavity Preparation / Q000145:classification* / Q000295:instrumentation; D003764:Dental Materials / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation; D008422:Materials Testing; D008434:Matrix Bands; D058105:Polymerization; D011829:Radiation Dosage; D012031:Refractometry; D012822:Silicon Dioxide / Q000737:chemistry; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D015040:Zirconium / Q000737:chemistry
D003188:Composite Resins; D003722:Dental Alloys; D003764:Dental Materials; C083568:Z100 composite resin; D013193:Stainless Steel; D012822:Silicon Dioxide; D015040:Zirconium