title: Influence of adhesion promoters and curing-light sources on the shear bond strength of orthodontic brackets.
abstract: BACKGROUND
  The effect of different curing units on bond strength of orthodontic brackets is still unclear when utilizing nanofilled composites in comparison with traditional Transbond-XT.
  
  
  OBJECTIVE
  To evaluate the influence of two adhesive promoters and two curing-light units on the shear bond strength (SBS) of orthodontic brackets.
  
  
  METHODS
  The factors under study were adhesive promoters (nanofilled composite - Filtek-Z350 flowable restorative and conventional orthodontic adhesive - Transbond XT) and curing-light units (halogen lamp - Ultralux and LED device - Radii-Call).
  
  
  METHODS
  Forty lower bovine incisors were utilized. The teeth were distributed in four groups (n = 10) according to the combination between adhesive promoters and curing-light units. Scotchbond Multipurpose-Plus and Transbond-XT primer were used to bond Filtek-Z350 Flowable Restorative and Transbond-XT, respectively. After storage in distilled water for 24 h, the brackets were subjected to SBS test at a speed of 0.5 mm/min until bracket debonding. The Adhesive Remnant Index (ARI) was assigned at fractured specimens.
  
  
  METHODS
  Analysis of variance and Tukey test were utilized. The Kruskal-Wallis test was used to compare ARI scores between the groups (p<0.05).
  
  
  RESULTS
  There was statistically significant difference between the adhesive promoters tested. Transbond-XT showed higher SBS means than Filtek-Z350. There was no statistically significant difference between both curing-light units tested in this study, neither between ARI scores.
  
  
  CONCLUSIONS
  The conventional orthodontic adhesive presented higher bond strength than the nanofilled composite, although both materials interacted similarly to the teeth. The curing-light devices tested did not influence on bond strength of orthodontic brackets.
authors: Department of Dentistry at Potiguar University (Laureate International Universities), Natal, RN, Brazil.
authors: Claudia Tavares
authors: CT
authors: Machado
authors: Boniek Castillo Dutra
authors: BC
authors: Borges
authors: Gustavo Jales Rodrigues
authors: GJ
authors: Araujo
authors: Alex Jose Souza
authors: AJ
authors: dos Santos
authors: Fabio Roberto
authors: FR
authors: Dametto
authors: Fabio Henrique de Sa Leitao
authors: FH
authors: Pinheiro
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental / Q000145:classification*; D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation; D053761:Nanocomposites / Q000737:chemistry; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D058105:Polymerization; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; D010756:Phosphoric Acids; D019279:Resin Cements; C425844:Scotchbond Multi-Purpose Plus; C477790:Transbond XT; C516047:Transbond XT Light Cure Adhesive Primer; C533204:filtek Z350; D014867:Water; C030242:phosphoric acid