title: Effect of flowable composite liner and glass ionomer liner on class II gingival marginal adaptation of direct composite restorations with different bonding strategies.
abstract: OBJECTIVE
  The purpose of the present study was to comparatively evaluate the effect of flowable composite resin liner and resin modified glass ionomer liner on gingival marginal adaptation of class II cavities restored using three bonding agents (Single Bond 3M ESPE, One Coat Self Etching Bond Coltene Whaledent; Adper Easy Bond Self-Etch Adhesive 3M ESPE) and respective composite resins, under cyclic loading. The marginal adaptation was evaluated in terms of 'continuous margin' (CM) at the gingival margin.
  
  
  METHODS
  Ninety class II cavities with margins extending 1mm below the cement-enamel junction were prepared in extracted mandibular third molars. The samples were divided into three groups: no liner placement; 0.5-1mm thick flowable resin liner placement (Filtek Z350 XT flowable resin) on gingival floor and; light cure glass ionomer (Ketac N100) liner. The groups were further subdivided into three sub-groups on the basis of the bonding agents used. Cavities were restored with composite resins (Z350 for Single Bond and Adper Easy Bond; and Synergy D6 Universal, for One Coat Self Etching Bond) in 2mm increments and the samples were mechanically loaded (60N, 1,50,000 cycles). Marginal adaptation was evaluated using a low vacuum scanning electron microscope. Statistical analysis was done with two way ANOVA with Holm-Sidak's correction for multiple comparisons.
  
  
  RESULTS
  Placement of flowable composite liner significantly improved the CM values of Single Bond (78±11%) and One Coat Self Etching Bond (77±9%) compared with no liner group, but the values of CM of Adper Easy Bond were not improved (61±12%). Placement of glass ionomer liner significantly improved the values of CM in all the sub-groups (78±9%, 72±10% and 77±10% for Single Bond, One Coat Self Etching Bond & Adper Easy Bond respectively) compared with no liner group.
  
  
  CONCLUSIONS
  Placement of liners improved the values of 'continuous margin' in the gingival floor of the proximal cavities restored with composite resins using different bonding agent.
  
  
  CONCLUSIONS
  Placement of flowable composite liner or glass ionomer liner will improve the marginal integrity of composite restorations using etch-and-rinse and two bottle-two step self etch adhesives. To improve the marginal integrity of a single bottle adhesive, glass ionomer liner should be applied.
authors.affiliation: Department of Conservative Dentistry & Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India. Electronic address: drvivekaggarwal@gmail.com.
authors.forename: Vivek
authors.initials: V
authors.lastname: Aggarwal
authors.affiliation: Department of Conservative Dentistry & Endodontics, SGT Dental College, Gurgaon, India.
authors.forename: Mamta
authors.initials: M
authors.lastname: Singla
authors.affiliation: Department of Conservative Dentistry & Endodontics, SGT Dental College, Gurgaon, India.
authors.forename: Suman
authors.initials: S
authors.lastname: Yadav
authors.affiliation: Department of Conservative Dentistry & Endodontics, SGT Dental College, Gurgaon, India.
authors.forename: Harish
authors.initials: H
authors.lastname: Yadav
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003736:Dental Cavity Lining / Q000379:methods*; D003737:Dental Cavity Preparation / Q000145:classification*; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000145:classification*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D005899:Glass Ionomer Cements; D008689:Methacrylates; C426984:One Coat Bond; D019279:Resin Cements; C452441:Synergy composite resin; C584661:easy bond; C533204:filtek Z350; C115612:single bond; C061499:Ketac-Bond; D017438:Bisphenol A-Glycidyl Methacrylate
keywords: Dentine bonding agent; Etch-and-rinse adhesives; Marginal adaptation; Self etch