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Abstract
Progressive bone resorption of the edentulous ridge is a major concern when rehabilitation of the mandible with a complete denture is considered. Complete mandibular dentures seem insufficient in re-establishing oral function, chewing efficacy and bite force [1]. The introduction of implant-retained overdenture prostheses (OVD) has led to a paradigm shift in the management of complete edentulism. Hence, implantretained OVD have been proposed as the gold standard treatment for the fully edentulous mandible [2].
The long-term efficacy, clinical efficiency and patient satisfaction with this type of restorative solution have been successfully established in many retrospective and longitudinal trials [2, 3]. Following the traditional loading protocol, dental implants should be connected to the prosthesis when the process of osseointegration is complete. The recommended healing timelines before loading of maxillary and mandibular implants with OVD are 6 and 3 months, respectively [4]. For a long time, immediate loading of dental implants was considered detrimental for osseointegration. The evolution of implant systems, designs and surfaces has enabled shortened healing times without jeopardizing osseointegration and implant success rate [5]. The utilization of these enhanced surfaces may improve implant success in patients with systemic conditions such as diabetes and osteoporosis, in compromised sites and when an immediate or early loading protocol is considered [6, 7]
The use of immediate loading protocols may offer several advantages when compared to a delayed loading approach. These benefits include a shortened treatment period, improved function, reduced chair time for provisional relining, improved patient acceptance and no need for a second surgical intervention. A recent systematic review reported similar implant success rates with immediate loading protocols versus conventional approaches but the authors advocated for more data based on randomized controlled clinical trials to improve the quality of the evidence [8]. Immediate loading of dental implants using 2 or 4 implants splinted with a bar supporting mandibular OVD has been validated and documented by case series and prospective studies [3]. However, limited evidence exists based on randomized controlled clinical trials comparing 2 unsplinted implants supporting OVD with immediate loading versus a conventional approach.
Therefore, the aim of this single-blind, randomized controlled clinical trial was to clinically and radiographically evaluate the performance of 2 unsplinted implants supporting a Locator™ retained mandibular OVD using either an immediate or delayed loading protocol.
