Aim: This study aimed to assess the effect of two resilient attachments used for retention of mandibular over-denture supported by an implant and a natural tooth on the supporting structures throughout a one-year follow-up period.

Materials and methods: Fourteen patients with maxillary completely edentulous arches and only one standing natural mandibular canine were selected. Each patient received a dental implant with 10.5 mm length and 3.8 mm diameter at the canine region of the contralateral side of the mandible. The patients were divided into two groups according to the type of attachment used (n=7); BC group included patients who received mandibular over-dentures retained by bar clip attachment supported by an implant on one side and a natural tooth on the other side. BS group involved patients who received a mandibular implant splinted to the natural canine by bar joint attachment utilizing soft liner material. The patients of both groups were rehabilitated with conventional maxillary complete dentures. Clinical and radiographic assessment were performed immediately after over-denture delivery, six and twelve months from denture insertion. Clinical evaluation involved gingival index. Radiographic evaluation included measuring mesial, distal, buccal and lingual bone height differences.
Results: BC group recorded significantly higher bone loss compared to BS group around both dental implants and natural teeth.
Conclusion: Considering the limitations of this study, it could be concluded that soft liner retained over-dentures are more effective in decreasing bone resorption around the implants and natural teeth compared to clip retained over-dentures.