title: Effect of using silorane-based resin composite for restoring conservative cavities on the changes in cuspal deflection.
abstract: OBJECTIVE
  To investigate the effect of using two resin-composite materials for restoring conservative mesio-occluso-distal (MOD) cavities on the changes (incremental and cumulative) in cuspal deflection.
  
  
  METHODS
  Forty extracted sound human maxillary second premolars were subjected to standardized MOD cavity preparation and then divided into two groups (n=20). The first group of teeth was restored with Filtek Z250 (3M ESPE, St Paul, MN, USA), and Filtek P90 (3M ESPE, St Paul, MN, USA) was used in the second group. Incremental cuspal deflection was calculated by measuring the intercuspal distance between the indexed cusp tips before the restoration and at five-minute intervals up to 30 minutes using a stereomicroscope connected to a digital camera. Cumulative cuspal deflection for both materials was also calculated.
  
  
  RESULTS
  Comparing the incremental cuspal deflection of the tested groups at each time interval, it was found that there was no significant difference immediately after curing and at five, 15, 20, and 25 minutes. However, a significant difference was recorded at 10 and 30 minutes. For the cumulative cuspal deflection, Filtek P90 showed significantly lower deflection values than Filtek Z250 only after five minutes.
  
  
  CONCLUSIONS
  Incremental cuspal deflections of both materials over the tested intervals were almost comparable. However, after five minutes of curing, silorane-based resin composite surpassed the methacrylate-based resin composite in controlling the cumulative cuspal deflection.
authors.affiliation: Department of Restorative Dentistry, Faculty of Oral and Dental Medicine, Cairo University, Egypt.
authors.forename: N M
authors.initials: NM
authors.lastname: Shabayek
authors.forename: F M
authors.initials: FM
authors.lastname: Hassan
authors.forename: E H
authors.initials: EH
authors.lastname: Mobarak
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins / Q000737:chemistry / Q000494:pharmacology; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000379:methods*; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D058105:Polymerization; D019279:Resin Cements; D062047:Silorane Resins / Q000737:chemistry / Q000494:pharmacology; D019228:Tooth Crown / Q000187:drug effects
chemical_list: C438313:Clearfil SE Bond; D003188:Composite Resins; C444701:Filtek Z250; D019279:Resin Cements; D062047:Silorane Resins; C544925:filtek P90; C555513:silorane composite resin