Fracture load of long span fiber-reinforced acrylic resin provisional fixed partial denture

• Main Authors: Yu-Chiun Huang, 黃俞群
• Other Authors: Jen-Chyan Wang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/09222880717199329646

碩士 === 高雄醫學大學 === 牙醫學研究所碩士班 === 93 === Provisional fixed partial dentures of traditional PMMA resin often get fractured in areas of force concentration and cause clinical inconvenience. The purpose of this study was to evaluate the fracture load and fracture pattern of different fibers reinforced long span acrylic resin provisional restoration, and the relationships among fiber type, reinforced position/length and fracture load of samples. In the experiment, 80 standardized 4-unit bridge specimens over mandibular posterior region were fabricated with PMMA resin from a metal jig. Next, they were divided into 8 groups evenly. Positive control group were intact acrylic resin specimens, and negative control group were acrylic resin samples reinforced with 0.016×0.022 stainless wire. The experiment groups were acrylic resin samples reinforced with different length (4,18,30mm) of glass fiber (FibreKor) / polyethylene fibers (Construct), and were reinforced in connector between two pontics、extended to both side of the abutments and extended to the occlusal surface of both abutments respectively. All samples were under thermocycling (600×5℃/55℃, 2min/cycle). After that, the load was applied to the middle fossa of the molar pontics of fixed partial dentures by a 6 mm steel ball mounted in a universal testing machine. Finally the fracture load and fracture pattern of all specimens were recorded and the fracture surfaces of selective specimens were observed under SEM. The results revealed that specimens reinforced with 30mm glass fiber (676�b66.4 N) showed the highest fracture load, followed by 18mm glass fiber (661.9�b68.2 N), 18mm polyethylene fiber (651.4�b46.5 N), 30mm polyethylene fiber (612.0�b81.7 N), 4mm glass fiber (610.8�b63.2 N), 4mm polyethylene fiber (607.4�b75.8 N), Control group (413.2�b63.5 N), and the specimens with 4mm stainless wire exhibited the lowest values (382.6�b77.6 N). One-way ANOVA indicated significant differences between fiber reinforced groups and control groups/stainless wire reinforced group (P<0.001). Two-way ANOVA revealed that the fracture load are not statistically significant in the fiber reinforced groups no matter the fiber type or reinforced fiber length (P>0.05). As for the fracture pattern, all specimens are displayed “partial” fractures no matter with reinforcement or not. The results of this study indicate that fiber-reinforcement of FibreKor/Construct indeed enhances the fracture resistance of long span provisional fixed partial denture. Increase fiber reinforced length is not relatively significant increase the fracture load of long span fixed partial denture.