title: Influence of fiber-reinforced composites on the resistance to fracture of vertically fractured and reattached fragments.
abstract: BACKGROUND
  The aim of this in vitro study was to evaluate the fracture type and test the effects of 2 different fibers on fracture strength of roots with reattached fragments. The null hypothesis was that adding suitable fibers to the content of dual-cure adhesive resin cement increases the fracture resistance of reattached fragments under vertical forces.
  
  
  METHODS
  Root canals of 45 teeth were prepared, and the teeth were intentionally fractured into 2 separate fragments. Control groups (n = 7 each) consisted of unfractured teeth with instrumented and obturated or only instrumented root canals. The fractured teeth were divided into 3 groups (n = 15 each), and separated fragments were reattached by using (1) dual-cured resin cement (Clearfil SA), (2) dual-cured resin cement + polyethylene fiber (Construct), or (3) dual-cured resin cement + glass fiber (Stick-Net). Force was applied at a constant speed of 0.5 mm/min to the root until fracture. Mean load was recorded and analyzed statistically by using Kruskal-Wallis and Dunn tests (P = .05). Fracture types were analyzed by using χ(2) analysis with Yates correction.
  
  
  RESULTS
  Stick-Net demonstrated the lowest fracture resistance (P < .05), whereas Construct and Clearfil SA had similar fracture strengths (P > .05). The roots in the control group showed the highest fracture resistance. However, there was no statistically significant difference between the Construct, Clearfil SA, and control groups (P > .05).
  
  
  CONCLUSIONS
  Separated fragments of vertically fractured teeth can be reattached by using a dual-cured resin or by adding polyethylene fiber (Construct).
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ege University, İzmir, Turkey.
authors.forename: Bilge Hakan
authors.initials: BH
authors.lastname: Sen
authors.forename: Senem
authors.initials: S
authors.lastname: Yiğit Özer
authors.forename: Sadullah
authors.initials: S
authors.lastname: Kaya
authors.forename: Ozkan
authors.initials: O
authors.lastname: Adıgüzel
mesh_terms: D000293:Adolescent; D001732:Bite Force; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D020959:Polyethylene / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012008:Recurrence; D019279:Resin Cements / Q000737:chemistry; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000503:physiopathology / Q000628:therapy*; D014092:Tooth Root / Q000293:injuries* / Q000503:physiopathology; D055815:Young Adult
chemical_list: C438313:Clearfil SE Bond; D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements; C485628:Stick resin; C009753:fiberglass; D020959:Polyethylene; D019904:Polymethyl Methacrylate