Three-dimensional finite element analysis of metal and FRC adhesive fixed dental prostheses.
OBJECTIVE
The aim of this study was to evaluate stress distribution in anterior adhesive fixed dental prostheses (FDP) and at the tooth/framework interface. Metal (M-FDP) and glass fiber-reinforced composite (FRC-FDP) frameworks were compared.


METHODS
The design of the FDP consisted of retainers on a maxillary central incisor and canine with a pontic of a lateral incisor. Two different framework materials were compared: isotropic Au-Pd alloy and anisotropic continuous unidirectional E-glass FRC. Veneers in both cases were made of isotropic veneering hybrid composite. A 3-dimensional finite element model of a 3-unit FDP loaded with 154 N (at a 45-degree angle to the incisal edge of the pontic) was used to analyze stress distribution in the FDP and at the adhesive interface. A finite element analysis was used in calculation of the maximum principal stress and displacement.


RESULTS
The maximum displacement of FRC-FDP was higher than that of M-FDP. Stress concentrations were located equally in the connectors and at the occluding contact points in both framework types. Maximum principal stress of FRC-FDP was lower than that of M-FDP. Stress analysis further indicated that the maximum stress in the luting cement interface of FRC-FDP was located at the middle part of the retainers, whereas in the M-FDP, the maximum stress was located at the marginal edge of the retainers.


CONCLUSIONS
The FE model revealed differences in displacement and stress distribution between metal and FRC frameworks of FDP. The general observation was that FRC-FDP provided more even stress distribution from the occluding contact point to the cement interface than did M-FDP.
Shinya
Akikazu
A
Deptartment of Crowns and Bridges, Schood of Life Dentistry at Tokyo, The Nippon Dental University, Chiyoda-ku, Tokyo, Japan. akikazu.shinya@utu.fi
Yokoyama
Daiichiro
D
Lassila
Lippo V J
LV
Shinya
Akiyoshi
A
Vallittu
Pekka K
PK
D016880:Anisotropy; D001896:Boron Compounds / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003481:Cuspid / Q000502:physiology; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D003801:Dental Veneers; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation; D016379:Denture, Partial, Fixed, Resin-Bonded; D020342:Finite Element Analysis; D005898:Glass / Q000737:chemistry*; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D021621:Imaging, Three-Dimensional; D007180:Incisor / Q000502:physiology; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties
D001896:Boron Compounds; D003188:Composite Resins; D003722:Dental Alloys; D003764:Dental Materials; D006047:Gold Alloys; D008689:Methacrylates; D008768:Methylmethacrylates; D019279:Resin Cements; C496140:everStick; C009753:fiberglass; D010165:Palladium; C049495:Super-bond