Document Type : Original Article

Authors

1 Dept. of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran

2 Dentist

Abstract

Statement of Problem: About one out of every four individuals under the age of 18 will sustain a traumatic dental injury in the form of anterior incisal fracture. Development of fiber reinforced composite has provided new persp­ectives in the treatment of anterior fractured teeth.Purpose: The aim of this in vitro study was to investigate the effect and position of the fiber on the load bearing capacity of composite restorations on fragmented incisal edge of the upper central incisors.Materials and Methods: Eleven extracted maxillary incisors per group were prepared by cutting 3mm of the incisal edges horizontally. Group 1 was rest­ored with particulate filler composite (PFC), group 2 with PFC and fiber in the mid-palatal surface, and group 3 was restored with PFC and fibers in the two sides of the palatal surface with the distance of 0.5-1mm. All the restored teeth were stored in distilled water for 7 days before they were statically load­ed until they fractured in a universal testing machine. The data were analyzed using one way ANOVA and Tukey statistics. p 0.05 was considered as significant. Failure mode was visually examined.Results: The statistical analysis showed a significant decrease of fracture load from group 2 to the other two groups ( p =0.05). There was statistically significant differences between groups 1 and 2 ( p =0.0 19) and 2 and 3 ( p =0.036). No significant differences were founded between groups 1 and 3. The failure mode in group 1 was debonding of the restoration from the adhesive interface, while in group 2, more than 75% of the teeth fractured below the cementoenamel junction (CEJ) or other parts of teeth. In group 3, the fractures occurred in restoration.Conclusion: These results suggest that the incisally fractured tooth restored with fiber in the mid-palatal surface provide the highest load bearing capacity.KEY WORDS: Load bearing capacity; Anterior tooth; Fiber reinforced composite