Immediate Loading of Unsplinted Implant Retained Mandibular Overdenture: A Randomized Controlled Clinical Study
This clinical study aimed to clinically and radiographically compare the implant survival rate and peri-implant tissue response between immediate and delayed loading protocols for unsplinted implant retained mandibular overdentures. Twenty patients were enrolled to participate in this study. Each subject was randomly assigned to 1 of 2 treatment groups: test group patients' implants (n = 10), which were immediately loaded, and control group patients' implants (n = 10), which were conventionally loaded. Locator abutments were torqued to 15 Ncm at delivery. Attachments were picked up intraorally immediately after implant placement for the test group and at 3 months for the control group, and 3-lb retention inserts were placed. Marginal bone levels based on cone beam computed tomography fixed reference points were recorded at baseline and 12 months. Modified plaque index, gingival index, and implant stability quotients were recorded at baseline, 3 months, and 12 months. After 12 months, implant survival rate was 100% in both groups. Marginal bone levels, keratinized mucosa, modified plaque index, and gingival index were significantly different among the groups at 3- and 12-month intervals, whereas no significant differences were found in implant stability quotients between the groups. The fact that implant survival rate was 100% in both treatment groups suggests that, within the limitations of this study, immediate loading protocol for unsplinted implant retained mandibular complete overdenture is as predictable, safe, and successful as the delayed loading protocol. Implementing the immediate loading protocol for mandibular implant retained overdentures could shorten treatment time, which could lead to better patient's satisfaction.
Figure 1. Treatment protocol for test group. (a) Preoperative edentulous ridge. (b) Locator abutments delivered immediately after implant placement and 3-0 Vicryl interrupted sutures to secure the flaps. (c) Three-month follow-up visit to evaluate healing. (d) Locator attachments picked up into the intaglio surface of the mandibular denture and medium attachments were used for immediate function. Figure 2. Treatment protocol for control group. (a) Preoperative edentulous ridge. (b) Cover screws placed and flap secured with 3-0 Vicryl interrupted sutures. (c) Locator abutments delivered at 3 months. (d) Locator attachments picked up into the intaglio surface of the mandibular denture and medium attachments were used for immediate function.
Cone beam computerized tomography for control group made immediately after implant placement at baseline and at 12-month follow-up visit to measure the crestal bone changes around the platform of each implant at 4 sites (mesial [M], distal [D], buccal [B], and lingual [L]). (a) B and L crestal bone level measured from the most inferior point of the mandible at the implant site at baseline. (b) M and D crestal bone level measured from the most inferior point of the mandible at the implant site at baseline. (c) B and L crestal bone level measured from the most inferior point of the mandible at the implant site at 12 months. (d) M and D crestal bone level measured from the most inferior point of the mandible at the implant site at 12 months.
Cone beam computerized tomography for test group made immediately after implant placement at baseline and at 12-month follow-up visit to measure the crestal bone changes around the platform of each implant at 4 sites (mesial [M], distal [D], buccal [B], and lingual [L]). (a) B and L crestal bone level measured from the most inferior point of the mandible at the implant site at baseline. (b) M and D crestal bone level measured from the most inferior point of the mandible at the implant site at baseline. (c) B and L crestal bone level measured from the most inferior point of the mandible at the implant site at 12 months. (d) M and D crestal bone level measured from the most inferior point of the mandible at the implant site at 12 months.
Figure 5. Chart showing comparison between mean keratinized mucosa measurements at baseline, 3 months, and 1 year. Figure 6. Chart showing comparison between mean crestal bone loss around buccal (site B), distal (site D), lingual (site L), and mesial (site M) surfaces of implants in the test and control groups. Figure 7. Chart showing comparison between mean Osstell ISQ values of the test and control groups.
Contributor Notes