title: Fiber-reinforced composite fixed dental prostheses with various pontics.
abstract: OBJECTIVE
  To evaluate the load-bearing capacities of fiber-reinforced composite (FRC) fixed dental prostheses (FDP) with pontics of various materials and thicknesses.
  
  
  METHODS
  Inlay preparations for retaining FDPs were made in a polymer phantom model. Seventy-two FDPs with frameworks made of continuous unidirectional glass fibers (everStick C&B) were fabricated. Three different pontic materials were used: glass ceramics, polymer denture teeth, and composite resin. The FDPs were divided into 3 categories based on the occlusal thicknesses of the pontics (2.5 mm, 3.2 mm, and 4.0 mm). The framework's vertical positioning varied respectively. Each pontic material category contained 3 groups (n = 8/group). In group 1, pontics were fabricated conventionally with composite resin (G-ӕnial, GC) with one additional transversal fiber reinforcement. In group 2, the pontics were polymer denture teeth (Heraeus- Kulzer). Group 3 had an IPS-Empress CAD pontic (Ivoclar Vivadent) milled using a Cerec CAD/CAM unit. Groups 1 and 2 served as controls. Each FDP was statically loaded from the pontic until initial fracture (IF) and final fracture (FF). Initial-fracture data were collected from the load-deflection graph.
  
  
  RESULTS
  ANOVA indicated statistically significant differences between the materials and occlusal thicknesses (p < 0.001). Quadratic analysis demonstrated the highest correlation between the thickness of the pontic and IF and FF values with ceramic pontics (IF: p < 0.001; R2 = 0.880; FF: p < 0.001; R2 = 0.953).
  
  
  CONCLUSIONS
  By increasing the occlusal thickness of the pontic, the load-bearing capacity of the FRC FDPs may be increased. The highest load-bearing capacity was obtained with 4.0 mm thickness in the ceramic pontic. However, with thinner pontics, polymer denture teeth and composite pontics resulted in higher load-bearing values.
authors.forename: Leila
authors.initials: L
authors.lastname: Perea
authors.forename: Jukka P
authors.initials: JP
authors.lastname: Matinlinna
authors.forename: Mimmi
authors.initials: M
authors.lastname: Tolvanen
authors.forename: Lippo V
authors.initials: LV
authors.lastname: Lassila
authors.forename: Pekka K
authors.initials: PK
authors.lastname: Vallittu
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D017076:Computer-Aided Design; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry; D003779:Denture Design; D003834:Denture Precision Attachment; D003830:Denture, Partial, Fixed; D005898:Glass / Q000737:chemistry*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D003765:Models, Dental; D019904:Polymethyl Methacrylate / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic / Q000379:methods; D014093:Tooth, Artificial
chemical_list: D000538:Aluminum Silicates; D003188:Composite Resins; D003764:Dental Materials; C520133:IPS e.max CAD LT; D019279:Resin Cements; C496140:everStick; C009753:fiberglass; D003776:Dental Porcelain; C078519:leucite; C023506:Glass ceramics; D019904:Polymethyl Methacrylate