Radiographic Changes in Immediately Restored Dental Implants, 3 Year Results

Objectives: Radiographic bone loss (BL) around immediately restored implants (R) was compared to submerged (S) and to non submerged non restored implants (NR). Methods: Patients treated for chronic periodontitis, requiring implant therapy were accepted. Periodontal treatment including oral hygiene instructions and reinforcement, scaling and root planning and periodontal surgery as necessary were rendered prior to commencement of the study. Immediately following implant surgery, a provisional fixed restoration was provided for some implants (R). The rest either received healing abutments (NR), or were submerged for a healing period of 6 months (S). 2nd stage surgery was performed at 6 months for the S group and restorations completed thereafter. Radiographs were taken as part of patient treatment and data collection at baseline, 6, and 12 months and then annually. 3 year radiographic BL was compared between the 3 groups, expressed in mm as mean ±SE. Results: 74 implants were inserted in 19 patients, of which 41 in extraction sites. 12 implants failed and were excluded from the analysis. Mean BL between 0-6, 6-12, 0-36 months was 0.947±0.1, 0.484±0.096, 1.503±0.124, respectively. 0-6 month BL of R, NR and S were 0.988±0.127, 0.933±0.253, 0.877±0.214, respectively, p=0.8925. Significantly greater 6-12 month bone loss was observed for S (0.854±0.12) vs. R (0.242±0.13,), p=0.008, (NR 6-12 month BL was 0.352±0.36). 0-36 month BL was significantly higher in S vs. R and S vs. NR. 0-36 month BL of R, NR and S were 1.28±0.14, 0.988±0.326, 2.06±0.21, p=0.0042. BL of extraction site implants did not differ from implants placed in healed sites. Conclusions: Two stage dental implants exhibited greater BL than single stage implants. This phenomenon might be related to the additional 2nd stage surgery performed on these implants.