title: Comparing orthodontic bond failures of light-cured composite resin with chemical-cured composite resin: A 12-month clinical trial.
abstract: BACKGROUND
  In this clinical trial, we evaluated and compared bond failure rates of light-cured composite resin vs chemical-cured composite resin for 12 months.
  
  
  METHODS
  Twenty-two subjects (356 stainless steel brackets) were included in this study, and a split-mouth design was used to randomly allocate diagonally opposite quadrants to either chemical-cured (178 brackets) or light-cured (178 brackets) composite resin; the brackets came from the same manufacturer. The survival and failure rates of the brackets were evaluated by the mode of polymerization. The overall bracket survival rates were estimated using the Kaplan-Meier product limit estimate.
  
  
  RESULTS
  There were no significant differences in the bond failure rates between the chemical-cured and the light-cured composites (P = 0.52). Bond failures were greater in posterior teeth (6.7%) than in anterior teeth (1.2%). The highest failure rate was observed in the second premolars (7.7%).
  
  
  CONCLUSIONS
  The overall failure rate of brackets with the 2 bonding systems was 2.8%, which is acceptable for clinical use. The polymerization mode did not influence the bracket survival rate significantly.
authors.affiliation: Postgraduate resident, Division of Orthodontics, Faculty of Dentistry, University of Khartoum, Khartoum, Sudan.
authors.forename: Rufaida E
authors.initials: RE
authors.lastname: Mohammed
authors.affiliation: Associate professor, Division of Orthodontics, Faculty of Dentistry, University of Khartoum, Khartoum, Sudan. Electronic address: skabbas@hotmail.com.
authors.forename: Shaza
authors.initials: S
authors.lastname: Abass
authors.affiliation: Professor of restorative dentistry and vice dean for Research and Postgraduate Studies, College of Dentistry, Princess Nourah Bint Abdelrahman University, Riyadh, Saudi Arabia.
authors.forename: Neamat H
authors.initials: NH
authors.lastname: Abubakr
authors.affiliation: Assistant professor of statistics, Faculty of Mathematical Science, University of Khartoum, Khartoum, Sudan; assistant professor of statistics, Faculty of Science, Northern Border University, Arar, Saudi Arabia.
authors.forename: Zakariya M S
authors.initials: ZM
authors.lastname: Mohammed
mesh_terms: D000293:Adolescent; D000328:Adult; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003799:Dental Stress Analysis; D004868:Equipment Failure; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D055115:Light-Curing of Dental Adhesives; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008422:Materials Testing; D016910:Orthodontic Brackets; D009971:Orthodontics, Corrective / Q000379:methods*; D058105:Polymerization; D011446:Prospective Studies; D013193:Stainless Steel; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D013193:Stainless Steel