title: Fracture resistance of fragmented incisal edges restored with fiber-reinforced composite.
abstract: OBJECTIVE
  The aim of this study was to determine the static load-bearing capacity of fractured incisors restored with the conventional adhesive-composite technique or by using fiber-reinforced composites (FRC).
  
  
  METHODS
  Twelve extracted sound maxillary incisors per group were prepared by cutting the incisal (one-third) part of the crown horizontally. Restorations were made using three techniques. Group A (control group) was restored by reattaching the original incisal edge to the tooth. Group B was restored using particulate filler composite (PFC). Group C was restored with PFC and FRC by adding a thin layer of FRC on the palatal surface of tooth. The bonding system used was the conventional etch system with primer and adhesive. All restored teeth were stored in water at room temperature for 24 h before they were statically loaded until fracture in a universal testing machine. Data were analyzed using ANOVA (p = 0.05). Failure modes were visually examined.
  
  
  RESULTS
  Group A (reattaching fractured incisal edge) revealed the lowest load-bearing values, whereas preparation of the new incisal part with PFC revealed 148% higher load-bearing values compared to Group A. Group C (teeth restored with FRC) revealed a 254% higher load-bearing capacity than the control group. ANOVA revealed that the restoration technique significantly affected load-bearing capacity (p < 0.001). The failure mode in Groups A and B was debonding of the restoration from the adhesive interface, while in group C, 50% of the teeth fractured below the cementoenamel junction.
  
  
  CONCLUSIONS
  These results suggest that an incisally fractured tooth restored with a combination of PFC and FRC provide the highest load-bearing capacity.
authors.affiliation: Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku, Finland. sufgar@utu.fi
authors.forename: Sufyan K
authors.initials: SK
authors.lastname: Garoushi
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Ballo
authors.forename: Lippo V J
authors.initials: LV
authors.lastname: Lassila
authors.forename: Pekka K
authors.initials: PK
authors.lastname: Vallittu
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis / Q000295:instrumentation; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006801:Humans; D007180:Incisor / Q000293:injuries* / Q000503:physiopathology; D008422:Materials Testing; D019904:Polymethyl Methacrylate / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D019237:Tooth Cervix / Q000503:physiopathology; D014082:Tooth Fractures / Q000503:physiopathology*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C485628:Stick resin; C496140:everStick; C009753:fiberglass; D019904:Polymethyl Methacrylate