Fennis Willem M M, Wolke Joop G C, Machado Camilo, Creugers Nico H J, Kreulen Cees M
Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
Am J Dent. 2013 Feb;26(1):39-43.
To assess whether dentin pins increase shear resistance of extensive composite restorations and to compare performance of mini fiber-reinforced composite (FRC) anchors with metal dentin pins in the laboratory.
30 extracted sound molars were randomly divided into three groups. Occlusal surfaces were ground flat with a standard surface area and resin composite restorations were made in Group A. In Groups B and C similar restorations were made, with additionally four metal pins placed in Group B and four FRC pins in Group C. Specimens were statically loaded until failure occurred. Failure modes were characterized as intact remaining tooth substrate (adhesive or cohesive failure of restoration) or fractured remaining tooth substrate.
Mean failure stresses were 6.5 MPa (SD 3.2 MPa) for Group A, 9.7 MPa (SD 2.6 MPa) for Group B and 9.2 MPa (SD 2.6 MPa) for Group C. Difference in mean failure stresses between Group A and Groups B and C was statistically significant (P = 0.01), while the difference between Groups B and C was not (P = 0.63). Failures of the restoration without fracture of tooth substrate were seen for 80% of specimens in Group A and 20% in Groups B and C (P = 0.04).
评估牙本质钉是否能提高大面积复合树脂修复体的抗剪切力，并在实验室中比较微型纤维增强复合材料（FRC）锚钉与金属牙本质钉的性能。
将30颗拔除的健康磨牙随机分为三组。将咬合面磨平至标准表面积，并在A组制作树脂复合材料修复体。在B组和C组制作类似的修复体，B组额外放置4颗金属钉，C组额外放置4颗FRC钉。对试件进行静态加载直至发生破坏。破坏模式分为剩余牙齿基质完整（修复体的粘结或内聚破坏）或剩余牙齿基质断裂。
A组的平均破坏应力为6.5MPa（标准差3.2MPa），B组为9.7MPa（标准差2.6MPa），C组为9.2MPa（标准差2.6MPa）。A组与B组和C组之间的平均破坏应力差异具有统计学意义（P = 0.01），而B组和C组之间的差异无统计学意义（P = 0.63）。A组80%的试件修复体发生破坏而牙齿基质未断裂，B组和C组为20%（P = 0.04）。
