Introduction: After maxillectomy, patients suffer a substantial loss, not only of soft tissue but also of bone, resulting in ailing retention of conventional obturators. Therefore, implant-retained obturator can be a better treatment option for maxillectomy patients achieving sufficient retention and restoring oral function. For retaining obturators, splinted or non-splinted attachment systems can be used; each having unique stress transmission pattern in alveolar bone surrounding implants under load of mastication and functional forces.
Objectives: This study was done to compare stress distribution in peri-implant tissues of implant-retained obturators using two different attachment designs; ball and socket (non-splinted) attachment and Hader bar and clip (splinted) attachment.
Materials and Methods: An epoxy resin maxillary model of completely edentulous patient with unilateral maxillary defect (Brown's class IIA) was used in which two parallel dental implants were placed at the canine and second premolar regions on the intact side. Thirty obturators were constructed representing two groups; each using distinct attachment system. Group I received 15 pair of ball (non-splinted) attachment and Group II received 15 Hader bar-clip (splinted) attachment. Using the universal testing machine, vertical and oblique loads (30⁰ and 45⁰) of 50 and 100 N were applied bilaterally on the central occlusal fossae of maxillary first molars, and stress distribution was computed using strain gauges and compared between the two groups.