title: In vitro retention loss of attachment-retained removable partial denture.
abstract: OBJECTIVE
  To investigate the importance of attachment types on the retention loss of extracoronal attachment-retained removable partial dentures depending on the usage period.
  
  
  METHODS
  In order to observe the retention loss of 5 different attachments (OT Strategy, OT Strategy-metal protected, Vario-stud-snap and Vario-soft 3 and ERA-RV) over time, attachment-retained partial dentures representing Kennedy II mod. I case were placed in a custom-made, retention test machine. For each minute, eight separating and joining movements were performed and retention values (Newton) of the attachments were recorded by computer. The retention tests implemented in 540,1080 and 2160 cycles. The data were evaluated statistically according to the two-way ANOVA and Tukey parametrical tests.
  
  
  RESULTS
  The slide type attachment providing the best retention force was observed to be the most worn out by this process (p < 0.01) while the ball type attachments, which typically have the lesser retention force, showed less retention loss (p < 0.01).
  
  
  CONCLUSIONS
  It can be concluded that the retention attributes of the attachment-retained dentures were affected by the specific type of precision attachment as well as the usage period.
  
  
  CONCLUSIONS
  Precision attachments with ball-type plastic matrices may be recommended for the clinical use due to their retention stability over time.
authors.affiliation: Professor, Department of Prosthodontics, Faculty of Dentistry, Ankara University, Ankara, Turkey.
authors.forename: Gülsen
authors.initials: G
authors.lastname: Can
authors.affiliation: Specialist Prosthodontist, DDS, PhD, Department of Prosthodontics Instanbul İl Özel İdaresi, Ağiz ve Diş Sağliği Hastanesi, Istanbul Turkey.
authors.forename: Baransel
authors.initials: B
authors.lastname: Özmumcu
authors.affiliation: PhD Student, DDS, Department of Prosthodontics, Faculty of Dentistry, Ankara University, Ankara, Turkey, Phone: +905359362373 e-mail: paltinci@hotmail.com.
authors.forename: Pinar
authors.initials: P
authors.lastname: Altinci
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry; D003442:Crowns; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D019554:Dental Restoration Wear; D003799:Dental Stress Analysis / Q000295:instrumentation; D003779:Denture Design; D003834:Denture Precision Attachment / Q000145:classification*; D003781:Denture Retention / Q000295:instrumentation; D003832:Denture, Partial, Removable; D006801:Humans; D008422:Materials Testing; D009757:Nylons / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D003764:Dental Materials; D009757:Nylons