title: Bond strength of a self-adhesive resinous cement to root dentin irradiated with a 980-nm diode laser.
abstract: OBJECTIVE
  To assess the bond strength of Rely-X Unicem (RX), in comparison with Cement-Post (CP), to the cervical, middle and apical thirds of root canal dentin irradiated with a 980-nm diode laser.
  
  
  METHODS
  Forty maxillary canines were separated into four equal groups according to the cement used and the laser surface treatment: RX/laser irradiation (LI) group; RX/no irradiation (NI) group; CP/LI group; and CP/NI group. Two slices (2-mm thick) of each root third were submitted to a push-out test to assess the bond strength of the cement to the root canal dentin. The data obtained were submitted to two-way ANOVA and fracture analysis was performed by scanning electron microscopy.
  
  
  RESULTS
  The type of cement as well as 980-nm LI at the different root canal thirds significantly affected the bond strength values (p < 0.05). LI promoted an increase in bond strength of RX in all root thirds (p < 0.05). For all groups, bond strength to the cervical third was highest, followed by the middle and apical thirds (p < 0.05). When the cements were compared, RX always presented the highest bond strength in comparison with CP, irrespective of the laser application (p < 0.05). Fracture analysis showed a predominance of mixed failures for RX and of adhesive failure between dentin and cement for CP, irrespective of the laser application.
  
  
  CONCLUSIONS
  The 980-nm LI promoted an increase in bond strength of the self-adhesive resinous cement to root dentin.
authors.affiliation: Department of Restorative Dentistry, Dental Materials Area, Piracicaba School of Dentistry, Campinas State University, Piracicaba, São Paulo, Brazil.
authors.forename: Lucas Da Fonseca Roberti
authors.initials: Lda F
authors.lastname: Garcia
authors.forename: Lucas Zago
authors.initials: LZ
authors.lastname: Naves
authors.forename: Lourenço
authors.initials: L
authors.lastname: Correr-Sobrinho
authors.forename: Simonides
authors.initials: S
authors.lastname: Consani
authors.forename: Fernanda De Carvalho Panzeri
authors.initials: Fde C
authors.lastname: Pires-De-Souza
mesh_terms: D000704:Analysis of Variance; D019245:Compressive Strength; D003481:Cuspid; D001840:Dental Bonding; D003786:Dental Pulp Cavity; D003799:Dental Stress Analysis; D003804:Dentin / Q000528:radiation effects; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005898:Glass; D006801:Humans; D054023:Lasers, Semiconductor; D008422:Materials Testing; D011176:Post and Core Technique; D019279:Resin Cements / Q000737:chemistry; D018709:Statistics, Nonparametric; D014092:Tooth Root; D019553:Tooth, Nonvital
chemical_list: D017220:Dentin-Bonding Agents; C483701:Rely X Unicem; D019279:Resin Cements; C009753:fiberglass