Title Locators versus bar overdenture attachment systems: insufficient evidence to compare long-term retention
Clinical Question Does an implant-supported overdenture maintain greater long-term retention with a bar or with Locator attachments?
Clinical Bottom Line The currently available data on this subject is both low level and inconclusive as to which type of attachment system maintains superior retention over time. The variable results suggest that not all bar attachment systems are created equal, and that retention may vary greatly based on which system is used. However, all attachment systems tested provided clinically sufficient acceptable levels of retention.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
23566266Kobayashi et al./201410 mandibular models in each group (Locator attachment, and SFI-bar)Laboratory study
Key resultsFollowing cyclic insertion/removal simulating 10 years of wear, the SFI-bar attachment system maintained greater retention than the Locator attachments.
28387994ELsyad et al./ 20171 maxillary denture for each group (Locator attachments, Dolder bar) measured 5 timesLaboratory study
Key resultsFollowing cyclic insertion/removal simulating 6 months of wear, all Locator attachments (clear, pink, and blue) maintained greater retention and stability than the Dolder bar attachment system. The Locator attachments with lower initial retention (clear and pink) showed greater retention loss than those with higher initial retention (blue) following cycling.
Evidence Search ((((("dentures"[MeSH Terms] OR "dentures"[All Fields] OR "denture"[All Fields]) AND (((implant[All Fields] AND supported[All Fields]) OR (implant[All Fields] AND retained[All Fields])) OR (implant[All Fields] AND assisted[All Fields]))) AND ((locator[All Fields] AND attachment[All Fields]) OR locator[All Fields])) AND (((bar[All Fields] AND attachment[All Fields]) OR bar[All Fields]) OR (hader[All Fields] AND bar[All Fields]))) AND (("retention (psychology)"[MeSH Terms] OR ("retention"[All Fields] AND "(psychology)"[All Fields]) OR "retention (psychology)"[All Fields] OR "retention"[All Fields]) OR stability[All Fields])) AND (("Wear"[Journal] OR "wear"[All Fields]) OR (attachment[All Fields] AND ("Wear"[Journal] OR "wear"[All Fields])))
Comments on
The Evidence
Validity: The evidence regarding wear in various overdenture attachment systems is both sparse and of low quality. Included studies were limited to in vitro lab analyses with small sample sizes. Perspective: Larger sample sizes and quantitative in vivo studies are necessary to reliably compare the long-term retention of different overdenture attachment systems.
Applicability Implant-retained overdentures are becoming an increasingly popular treatment option for edentulous patients seeking improved retention, but they require more frequent maintenance due to wear of the attachment systems. Benchtop studies have demonstrated that a variety of attachment systems provide clinically acceptable retention for overdentures over time, but there is insufficient information to demonstrate a definitive retentive advantage of any one system at this time.
Specialty (General Dentistry) (Prosthodontics)
Keywords Dental implant, overdenture, attachment, bar, locator, retention
ID# 3352
Date of submission 10/26/2018
E-mail bergeron@uthscsa.edu
Author Clara Bergeron, DDS
Co-author(s) e-mail
Faculty mentor Dr. E Matthew Lamb
Faculty mentor e-mail LambEM@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available