title: [Effects of clasp designs of Kennedy Class II RPD on the displacement of alveolar bone around the abutment tooth--an under load hologram study].
abstract: OBJECTIVE
  This article is to investigate the effects of different clasp designs of Kennedy class II RPD on the displacement of alveolar bone around the abutment tooth.
  
  
  METHODS
  This experiment was carried out by using a separate human mandible. Five clasp designs were examined in this experiment, including RPA, RPI, modified RPI (mRPI), three-arm clasps and buccal wrought wired three-arm clasps. Hologramatic measurement was applied to record the different effects of these five designs of clasps on buccal and lingual alveolar bone.
  
  
  RESULTS
  The RPI clasp was found to cause the smallest bone displacement. Generally, the clasps with the mesial occlusal rest (RPA, RPI, mRPI) caused smaller bone displacements than those with distal occlusal rests. The bar clasps brought about evenly spread bony displacements, however, the circumferential clasp caused highly concentrated displacement around apical site of the abutment tooth.
  
  
  CONCLUSIONS
  The results suggest that mesial occlusal rests and bar clasps are preferable designs in this kind of prostheses.
authors.affiliation: College of Stomatology, West China University of Medical Sciences.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Xiao
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: Q
authors.initials: Q
authors.lastname: Fu
mesh_terms: D000539:Alveolar Process; D002508:Cephalometry; D000044:Dental Abutments; D016734:Dental Clasps; D003799:Dental Stress Analysis; D003832:Denture, Partial, Removable; D006801:Humans