title: Comparison of ball and telescopic crown attachments in implant-retained mandibular overdentures: a 5-year prospective study.
abstract: OBJECTIVE
  Implant success, peri-implant conditions, and prosthodontic maintenance requirements were evaluated and compared for mandibular overdentures supported by two implants and retained with ball or resilient telescopic crown attachments during a 5-year period.
  
  
  METHODS
  Twenty-five patients with an edentulous mandible each received two root-form dental implants in the mandibular interforaminal (canine) region. The type of denture attachment was chosen randomly; 13 patients received ball attachments and 12 patients received resilient telescopic crowns. Implant success and peri-implant conditions (bone resorption, pocket depth, Plaque Index, Gingival Index, Bleeding Index) as well as prosthodontic maintenance and patient satisfaction were evaluated annually during a 5-year follow-up period and compared with respect to the two retention modalities used.
  
  
  RESULTS
  Implant success, peri-implant conditions, and subjective patient satisfaction scores did not differ between the two retention modalities used. However, during the 5-year observation period, significantly more postinsertion complications/interventions for maintenance purposes were registered in the ball group (87 interventions, 61.1%) than in the telescopic crown group (53 interventions, 37.9%; P < .01). Differences in prosthodontic maintenance efforts were most significant in the second and third years (P < .05) of the follow-up period but were similar at the end of the study for both anchorage systems.
  
  
  CONCLUSIONS
  Both ball attachments and resilient telescopic crowns on isolated implants in the atrophic mandible are viable treatment options for implant-supported overdentures. No implant losses, good peri-implant conditions, and general patient satisfaction were noted. Although the frequency of technical complications was initially higher with ball attachments than with resilient telescopic crowns over a 5-year period, similar frequencies of maintenance efforts may be anticipated for both retention modalities.
authors.affiliation: Department of Prosthodontics, Medical University of Vienna, Austria. krennmair@aon.at
authors.forename: Gerald
authors.initials: G
authors.lastname: Krennmair
authors.forename: Rudolf
authors.initials: R
authors.lastname: Seemann
authors.forename: Michael
authors.initials: M
authors.lastname: Weinländer
authors.forename: Eva
authors.initials: E
authors.lastname: Piehslinger
mesh_terms: D000328:Adult; D000368:Aged; D000044:Dental Abutments; D003753:Dental Health Surveys; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000295:instrumentation; D019094:Dental Prosthesis, Implant-Supported / Q000295:instrumentation / Q000379:methods; D019232:Dental Restoration Failure; D003781:Denture Retention / Q000295:instrumentation* / Q000379:methods; D003826:Denture, Complete, Lower; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation* / Q000601:surgery; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible / Q000601:surgery; D008875:Middle Aged; D013516:Oral Surgical Procedures, Preprosthetic / Q000379:methods; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D016474:Weight-Bearing
chemical_list: D015921:Dental Implants