Influence of curing tip distance on resin composite Knoop hardness number, using three different light curing units.
This in vitro study evaluated the influence of curing tip distance on the Knoop Hardness Number (KHN) of a resin composite when using three different light curing units: (1) a halogen light (XL 1500 curing unit-3M), (2) a "softstart-polymerization" (Elipar Trilight curing in an exponential mode-ESPE) and (3) a PAC (Apolo 95E curing unit-DMD). The resin composite, Filtek Z250 (3M), was cured by these curing units at three light-tip distances from the resin composite: 0 mm, 6 mm and 12 mm. The resin composite specimens were flattened to their middle portion and submitted to 18 KHN measurements perspecimen. The results showed that for the Elipar Trilight unit, the hardness of the resin composite decreased as the light tip distance increased. The XL 1500 unit presented a significant decrease in hardness as the depth of cure of the resin composite increased. Apolo 95E caused a decrease in the resin composite hardness values when the depth of cure and light tip distance increased.
Caldas
Danilo Biazzetto de Menezes
DB
Piracicaba Dental School, Piracicaba-São Paulo, Brazil.
de Almeida
Janaina Bertoncelo
JB
Correr-Sobrinho
Lourenço
L
Sinhoreti
Mário Alexandre Coelho
MA
Consani
Simonides
S
D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D004867:Equipment Design; D006244:Hardness; D006801:Humans; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry; D013499:Surface Properties
D003188:Composite Resins; D003764:Dental Materials; C444701:Filtek Z250; D011108:Polymers