title: Effect of LED curing modes on the microleakage of a pit and fissure sealant.
abstract: OBJECTIVE
  To evaluate in vitro the curing effect of a very high intensity light-emitting diode (LED) unit and a conventional LED unit (including "soft-start" modes) on the microleakage of a pit and fissure sealant.
  
  
  METHODS
  120 intact caries-free human molars were randomly divided into six groups (n=20), sealed with Fissurit-F and polymerized using either a conventional halogen unit (Optilux) (Control group) in standard mode (40 seconds @ 600 mW/cm2); a very high intensity LED unit (Mini LED) in fast (10 seconds @ 1,100 mW/cm2) or soft-start mode (pulse mode: ten 1-second flashes @ 1,100 mW/cm2; exponential mode: exponential increase from 0 to 1,100 mW/cm2 within 10 seconds followed by 10 seconds @1,100 mW/cm2); or a conventional LED unit (Elipar Freelight) in standard (40 seconds @ 400 mW/cm2) or exponential mode (exponential increase from 0 to 400mW/cm2 within 12 seconds followed by 28 seconds @ 400 mW/cm2). Restored specimens were stored in distilled water at 37 degrees C for 24 hours. Specimens were then immersed in a 0.5% fuchsin dye solution for 24 hours, with half of the specimens from each group subjected to thermocycling (5/55 degrees C; x 1000) prior to dye immersion. After removal from the dye solution, specimens were sectioned and the degree of dye penetration scored. Data was statistically analyzed using the Kruskal-Wallis H test and the Mann-Whitney U-test (P< 0.05).
  
  
  RESULTS
  There was no statistically significant difference in microleakage of pit and fissure sealant polymerized using various curing techniques. Thermocycling regimens had no effect on either LED- or halogen-cured specimens.
authors: Department of Restorative Dentistry, Faculty of Dentistry, Ankara University, Turkey. analcaci@dentistry.ankara.edu.tr
authors: Adil
authors: A
authors: Nalçaci
authors: Nuran
authors: N
authors: Ulusoy
authors: Ciğem
authors: C
authors: Küçükeşmen
mesh_terms: D000180:Acrylic Resins / Q000627:therapeutic use; D003188:Composite Resins / Q000627:therapeutic use; D003763:Dental Leakage; D006219:Halogens; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008963:Molar / Q000528:radiation effects; D010895:Pit and Fissure Sealants / Q000737:chemistry / Q000528:radiation effects*; D011140:Polyurethanes / Q000627:therapeutic use; D018709:Statistics, Nonparametric
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D006219:Halogens; D010895:Pit and Fissure Sealants; D011140:Polyurethanes