Garoushi SK, Lassila LV, Vallittu PK.
Institute of Dentistry, University of Turku, Turku, Finland. firstname.lastname@example.org
J Contemp Dent Pract. 2007 Feb 1;8(2):9-16.
AIM: The aim of this study was to determine the compressive fatigue limits (CFLs) of fractured incisor teeth restored using either a conventional adhesive-composite technique or using fiber-reinforced composites (FRCs). METHODS AND MATERIALS: Fifteen extracted sound upper incisor teeth were prepared by cutting away the incisal one-third part of their crowns horizontally. The teeth were restored 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 to the palatal surface of the teeth. The bonding system used was a conventional etch system with primer and adhesive. All restored teeth were stored in water at room temperature for 24 h before they were loaded under a cyclic load with a maximum controlled regimen using a universal testing machine. The test employed a staircase approach with a maximum of 103 cycles or until failure occurred. Data were analyzed using analysis of variance (ANOVA) (p=0.05). Failure modes were visually examined. RESULTS: Group A (reattaching fractured incisal edge) revealed the lowest CFL values, whereas the creation of a new incisal edge with PFC revealed a 152% higher CFL value compared to Group A. Group C (teeth restored with FRC) revealed a 352% higher CFL than the control group. ANOVA revealed the restoration technique significantly affected the compressive fatigue limit (p<0.001). The failure mode in Group A and B was debonding of the restoration from the adhesive interface. While in Group C, the sample teeth fractured below their cemento-enamel junctions. CONCLUSION: These results suggested an incisally fractured tooth restored with the combination of PFC and FRC-structure provided the highest CFL. Keywords: Fiber-reinforced composite, FRC, compressive fatigue limit, CFL, incisal edge fracture, particulate filler composite resin, PFC resin Link/DOI: http://www.thejcdp.com/issue031/garoushi/index_nlm.htm