The aim of this qualitative study was to gain a deeper understanding of patient perceptions of wearing implant-retained overdentures with ball-shaped or cylindrical attachment systems. Twenty-two wearers of implant-supported overdentures participated in this qualitative study based on a randomized crossover clinical trial that aimed to compare a cylindrical attachment and a ball attachment. In phase I of the study, group A experienced ball attachments (n = 11) and group B Locator attachments (n = 11) for 1 year. Afterward, in phase II, the attachments were changed; group A received Locator attachments and group B received ball attachments. One week after the attachment's replacement, semistructured individual interviews were conducted. All interviews were audiotaped and transcribed. The analysis was guided by thematic content analysis. Most of the patients from both groups preferred the attachment they received in phase II, regardless the type. A major theme raised by the participants to justify their preference between the attachment types was prosthesis retention/stability, sometimes considered as a positive and other times as a negative factor. Other themes were also explored: oral function, pain, hygiene, previous experiences, confidence on the dentist's work, and esthetic. Aspects related to the retention/stability of the overdentures are the main concerns associated with the perceptions of most patients treated with implant overdentures regardless of the type of attachment. Adequate retention level should be identified and adjusted on an individual basis and maintained overtime as possible. Therefore, follow-up appointments should be planned for readjustment of the attachment's retention. Overretention should be avoided.
Keywords: dental implants; edentulous mandible; overdentures; precision attachment; qualitative research.