title: Microleakage under orthodontic brackets using high-intensity curing lights.
abstract: OBJECTIVE
  To compare the microleakage of the enamel-adhesive-bracket complex at the occlusal and gingival margins of brackets bonded with high-intensity light curing lights and conventional halogen lights.
  
  
  METHODS
  Forty-five freshly extracted human maxillary premolar teeth were randomly separated into three groups of 15 teeth each. Stainless steel brackets were bonded in all groups according to the manufacturer's recommendations. Specimens (15 per group) were cured for 40 seconds with a conventional halogen light, 20 seconds with light-emitting diode (LED), and 6 seconds with plasma arc curing light (PAC). After curing, the specimens were further sealed with nail varnish, stained with 0.5% basic-fuchsine for 24 hours, sectioned and examined under a stereomicroscope, and scored for microleakage for the enamel-adhesive and bracket-adhesive interfaces from both the occlusal and gingival margins. Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney U-tests with a Bonferroni correction.
  
  
  RESULTS
  The type of light curing unit did not significantly affect the amount of microleakage at the gingival or occlusal margins of investigated interfaces (P >.05). The gingival sides in the LED and PAC groups exhibited higher microleakage scores compared with those observed on occlusal sides for the enamel-adhesive and adhesive-bracket interfaces. The halogen light source showed similar microleakage at the gingival and occlusal sides between both adhesive interfaces.
  
  
  CONCLUSIONS
  High-intensity curing units did not cause more microleakage than conventional halogen lights. This supports the use of all these curing units in routine orthodontic practice.
authors.affiliation: Department of Conservative Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ulker
authors.forename: Tancan
authors.initials: T
authors.lastname: Uysal
authors.forename: Sabri Ilhan
authors.initials: SI
authors.lastname: Ramoglu
authors.forename: Huseyin
authors.initials: H
authors.lastname: Ertas
mesh_terms: D001641:Bicuspid; D055117:Curing Lights, Dental; D003763:Dental Leakage / Q000209:etiology*; D006219:Halogens; D006801:Humans; D055115:Light-Curing of Dental Adhesives / Q000009:adverse effects* / Q000295:instrumentation; D016910:Orthodontic Brackets / Q000009:adverse effects*; D019279:Resin Cements; D012666:Semiconductors; D013193:Stainless Steel; D014978:Xenon
chemical_list: D006219:Halogens; D019279:Resin Cements; C477790:Transbond XT; D013193:Stainless Steel; D014978:Xenon