title: Long-term clinical and prosthetic outcomes of soft liner and clip attachments for bar/implant overdentures: a randomised controlled clinical trial.
abstract: Long-term clinical and prosthetic outcomes of soft liner attachments for bar/implant overdentures were not sufficiently investigated. The aim of this trial was to evaluate clinical and prosthetic outcomes of resilient liner and clip attachments for bar/implant-retained mandibular overdenture after 7 years. Thirty edentulous male participants received two implants in the canine areas of the mandible. Three months later, implants were splinted with a resilient bar. Mandibular overdentures were connected to the bars with either clip (CR group, n = 15) or resilient liner (RR group, n = 15) attachments. Plaque index (PI), gingival index (GI), probing depth (PD), vertical bone loss (VBL), horizontal bone loss (HBLO) and prosthetic complications (PCs) were evaluated at denture delivery (T0), 6 (T6m), 12 (T1), 24 (T2), 36 (T3), 48 (T4), 60 (T5), 72 (T6) and 84 (T7) months after insertion. PI and GI increased significantly with time for CR and decreased significantly for RR (P < 0·001). PD increased at T1 (CR) and T6 m (RR) and then decreased thereafter (P < 0·05). VBL increased significantly with time in both groups (P < 0·005). HBLO increased at T2 (CR) and T1 (RR) and then decreased thereafter. CR recorded significant higher PI, GI, PD, VBLO and HBLO compared to RR at all observation times (P < 0·042). The survival rates were 96·6% and 100% for CR and RR after 7 years. The most common PCs for CR and RR were clip wears and separation of the resilient liner from the denture base, respectively. Within the limitations of this study, resilient liner attachments are recommended for bar/implant-retained mandibular overdentures than clip attachments in terms of peri-implant tissue health and prosthetic complications after 7 years.
authors.affiliation: Department of Removable Prosthodontics, Faculty of Dentistry, University of Mansoura, Eldakahlia, Egypt.
authors.forename: M A
authors.identifier: http://orcid.org/0000-0001-9514-6931
authors.initials: MA
authors.lastname: ELsyad
authors.affiliation: Department of Removable Prosthodontics, College of Oral and Dental Surgery, Misr University for Science and Technology, Cairo, Egypt.
authors.forename: N H
authors.initials: NH
authors.lastname: Shaheen
authors.affiliation: Department of Maxillofacial Prosthodontics, National Cancer Institute, Cairo University, Cairo, Egypt.
authors.forename: T M
authors.initials: TM
authors.lastname: Ashmawy
mesh_terms: D016301:Alveolar Bone Loss; D003774:Dental Plaque Index; D019094:Dental Prosthesis, Implant-Supported; D003819:Denture Bases; D003779:Denture Design; D003822:Denture Liners; D003781:Denture Retention; D003828:Denture, Overlay; D006801:Humans; D007575:Jaw, Edentulous / Q000601:surgery*; D008297:Male; D008334:Mandible / Q000601:surgery*; D008875:Middle Aged; D010512:Periodontal Index; D013997:Time Factors; D016896:Treatment Outcome
keywords: attachments; bar; clip; implant; mandibular; overdenture; soft liner