Stress distribution of one-piece and two-piece mini-Implant overdentures with various attachment systems and diameters: A finite element analysis

Abstract

Implant overdentures have become a reliable treatment option for edentulous patients because of their enhanced retention, stability, masticatory performance, and higher patient satisfaction compared to conventional complete dentures [1,2]. Mini-implants have a reduced diameter of <3.0 mm and are manufactured using biocompatible materials used for manufacturing standard-sized implants [3]. Mini-implant overdentures are beneficial alternatives for elderly patients with severely resorbed mandibles or physical conditions that hinder advanced surgeries such as bone reshaping or grafting when using standard-sized implants [4]. They are also associated with a reduced cost, as the relatively high cost of standard-sized implant overdentures could limit patients' willingness to accept treatment [5]. In addition, they require minimal intervention and lower operative time compared to standard-sized implants[6] and demonstrate adequate survival rates [7]. Despite these advantages, mini-implants reportedly have lower mechanical strength and increased risks of implant fractures and peri-implant bone damage [4,8]. Clinical studies have highlighted the threat of fatigue fractures in implants with diameters <3.5 mm. In addition, mini-implants showed considerably low strength in in vitro monotonic loading tests, indicating a risk of fracture [9,10]. Therefore, while determining the applications of implants with a diameter ≤3 mm, practitioners should exercise extreme caution, particularly in selecting implant designs that have been proven to affect the mechanical response of implants. The optimal mini-implant J Prosthodont Res. 2022; **(**):

Implant survival/success and peri‐implant outcomes of titanium‐zirconium mini implants for mandibular overdentures: Results from a 1‐year randomized clinical trial

“…In addition, the monolithic structure of one-piece mini-implants also avoids the risk of bacterial microleakage at the abutment-implant interface, which improves the maintenance of bone levels around implants in the long term (do Nascimento et al, 2012). It was also reported that onepiece mini implants show lower levels of biomechanical stress compared to two-piece mini-implants (Trang et al, 2022).…”