title: Furcation groove of maxillary first premolar, thickness, and dentin structures.
abstract: BACKGROUND
  Few studies mention the presence of furcation grooves in the palatal aspect of buccal roots in upper first premolars. Anatomic characteristics like external grooves or root curvatures predispose teeth to weakening during post placement. Roots with a large number of external sulci show more canal variations. Previous research found that the palatal wall is on average less than 1mm. There is a direct relation between the volume of dental structures and the capacity to resist occlusal loads. The purpose of this study was to evaluate the changes in dentin thickness and structures adjacent to the furcal groove.
  
  
  METHODS
  The percentage that represented furcation groove in the buccal root was specified. The sample size selected was n=20. Three horizontal slices were made to the buccal root, coronal, middle, and apical. The angles of the grooves and dentin thickness were measured with a profile projector.
  
  
  RESULTS
  In the coronal third, the depth of the groove was correlative with dentin thickness negatively, ie, while the depth increased, palatal dentin thickness decreased or vice versa. In the coronal and middle thirds, the palatal wall showed average dentin width smaller than the buccal. In some cases, the thickness was less than 1mm. In the apical third, palatal dentin thicknesses showed higher averages than the buccal. Structural changes were observed in dentin adjacent to the furcation groove. These results are discussed in the context of other research. Methodologic differences do not enable comparative studies.
  
  
  CONCLUSIONS
  Dentin thickness corresponding to the furcal groove is variable; it presents structural changes and must be taken into account in endodontic and prosthetic procedures.
authors.affiliation: Department of Endodontics, Fundacion CREO, Cordoba, Argentina. paolammertyn@hotmail.com
authors.forename: Paola A
authors.initials: PA
authors.lastname: Lammertyn
authors.forename: Susana B
authors.initials: SB
authors.lastname: Rodrigo
authors.forename: Mabel
authors.initials: M
authors.lastname: Brunotto
authors.forename: Marta
authors.initials: M
authors.lastname: Crosa
mesh_terms: D001641:Bicuspid / Q000033:anatomy & histology*; D003786:Dental Pulp Cavity / Q000033:anatomy & histology; D003804:Dentin / Q000033:anatomy & histology*; D006801:Humans; D008437:Maxilla; D019237:Tooth Cervix / Q000033:anatomy & histology; D019228:Tooth Crown / Q000033:anatomy & histology; D014092:Tooth Root / Q000033:anatomy & histology*