title: Capacity of coronal dentin to increase fiberglass post retention: a pull-out test.
abstract: OBJECTIVE
  To evaluate the capacity of residual dentin in the coronal part of the root canal to increase the retention of serrated fiberglass posts (Extra-glass P-6%).
  
  
  METHODS
  40 freshly-extracted maxillary central incisors were randomly and evenly divided into four test groups (TGs) with no (TG0), one (TG1), two (TG2) and three (TG3) coronal walls, respectively. After shaping, the canals were filled with gutta-percha and prepared to receive fiberglass posts. Coronal wall dentin was etched with 38% phosphoric acid for 60 seconds, rinsed, and dried. Dentin bonding agent (Prime & Bond NT) was applied, and fiberglass posts were luted for 8 mm into the post space using a self-cure composite (ResiLute). All samples were then subjected to tensile forces in a universal testing machine. Data were analyzed with ANOVA and Student t-tests (P< 0.01).
  
  
  RESULTS
  The samples with residual coronal dentin showed higher bond strength than the samples without residual crown walls (TG0=100.30N; TG1=201.83N; TG2=263.54N; TG3=278.86N). The differences between the groups were all statistically significant at P< 0.01, except for the difference in tensile strength between TG2 and TG3, which was not statistically significant. Residual crown walls significantly increased the tensile load required to displace the posts.
authors.affiliation: Unit of Restorative Dentistry and Endodontics, Department of Oral Sciences, Dental School, University G. D'Annunzio, Chieti, Italy.
authors.forename: Camillo
authors.initials: C
authors.lastname: D'Arcangelo
authors.forename: Gianni Domenico
authors.initials: GD
authors.lastname: Prosperi
authors.forename: Paola
authors.initials: P
authors.lastname: Passariello
authors.forename: Sergio
authors.initials: S
authors.lastname: Caputi
authors.forename: Vito Antonio
authors.initials: VA
authors.lastname: Malagnino
mesh_terms: D000704:Analysis of Variance; D017268:Dental Prosthesis Retention / Q000379:methods*; D003804:Dentin / Q000737:chemistry*; D006801:Humans; D011176:Post and Core Technique; D013718:Tensile Strength; D019228:Tooth Crown