Fracture resistance of weakened roots restored with relined or milled CAD-CAM glass fiber posts

• Published in: Dental Materials Journal Vol. 42; no. 1; pp. 92 - 98
• Main Authors: Belizane das Graças Oliveira MAIA, Thais da Silva Alves SANTOS, CARVALHO, Cláudio Antonio Talge, VERNER, Francielle Silvestre, JUNQUEIRA, Rafael Binato
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society for Dental Materials and Devices 25.01.2023; Japan Science and Technology Agency
• Subjects: Animals; CAD-CAM technology; CAD/CAM; CAM; Cattle; Chi-square test; Composite Resins; Compression; Compressive strength; Computer aided manufacturing; Computer-Aided Design; Dental roots; Dental Stress Analysis; Flared root canal; Fracture resistance; Fracture toughness; Glass; Glass fibers; Incisors; Materials Testing; Post and Core Technique; Resin Cements; Roots; Teeth; Tooth Fractures - prevention & control; Tooth Root; Variance analysis; CAD-CAM technology; Compressive strength; Post and core technique; Flared root canal; Fracture resistance
• ISSN: 0287-4547; 1881-1361
• DOI: 10.4012/dmj.2022-114

This in vitro study compared the fracture resistance of weakened roots restored with milled or relined glass fiber post (GFP). Seventy bovine incisors were divided into seven groups, according to the weakening protocol (none: control; medium-weakened: MW; highly-weakened: HW) and post anatomization technique (non-relined, relined with Bulk Fill or Z350 resin; milled GFP: M). Roots were thermomechanical cycled and submitted to compression. Frequencies and groups were compared by the chi-square test and two-factor ANOVA, Tukey’s, and t-test (α=5%). The HW-M obtained the lowest values, showing significant differences compared to all groups (p<0.001). The highest value was HW-Bulk fill, with significant difference compared to MW-M (p=0.037) and HW-M (p<0.001). The frequency of repairable fractures was 100% in the control, 87%, and 63% in the MW and HW, respectively. Relined or milled GFPs can be considered to rehabilitate weakened teeth since failure patterns were predominantly repairable in all groups.