title: Clinical application of stress-breaking ball attachment for implant overdenture.
abstract: METHODS
  The patient was a 62-year-old partially edentulous woman with missing bilateral premolars and molars in the mandibular jaw. The patient selected implant supported-removable partial denture rehabilitation. Implants were placed bilaterally at the distal extension of the denture base in order to minimize denture displacement. The stress-breaking ball (SBB) attachment consists of a flat-top ball head male and O-ring rubber female. The female was covered by a silicone housing with three amounts of space to allow three kinds of settlement (0.3 mm, 0.5 mm, and 0.7 mm); they were selected by thickness or pressure displacement of the mucosa and occlusal force. After the healing period, the SBB attachments (0.3 mm) were placed on the implants, and the implant-supported removable partial denture was then conventionally fabricated. The delivered denture had sufficient retention and appropriate stress breaking.
  
  
  CONCLUSIONS
  The advantages of SBB attachments over conventional attachments are as follows: (1) they prevent the implant from excessive occlusal force, (2) they are ready-made, (3) they show appropriate retention, and (4) they can be easily mounted on the denture base. The disadvantages of these attachments are as follows: (1) they are approximately 1mm higher than conventional ball attachments and (2) the retentive force cannot be adjusted.
  
  
  CONCLUSIONS
  The use of a stress-breaking attachment for implant overdenture rehabilitation should be considered so that the occlusal force is equally distributed between the alveolar ridge and the implants.
authors.affiliation: Division of Oral and Maxillofacial Implantology, Tsurumi University School of Dental Medicine, Yokohama, Japan. suzuki-ys@tsurumi-u.ac.jp
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Chikahiro
authors.initials: C
authors.lastname: Ohkubo
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Kurtz
mesh_terms: D000539:Alveolar Process; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003832:Denture, Partial, Removable; D005260:Female; D006801:Humans; D008334:Mandible; D008875:Middle Aged