Guided bone regeneration on peri-implant dehiscence defects with particulated and soft-type block bone substitutes- a randomized controlled clinical trial

15543 ORAL COMMUNICATION CLINICAL INNOVATIONS

Background

The application of particulated bone substitutes covered with resorbable collagen membrane is, currently, the most widely used for resolving peri-implant dehiscence defects, however, low volume stability of particulated graft materials has been one of the concerns for clinicians. The use of soft-type blocks of bone substitute materials may be an effective alternative to particulated substitutes, in terms of higher volume stability and mechnical properties.

Aim/Hypothesis

The aim of the study was to test whether particulated bone substitute used for guided bone regeneration (GBR) on peri-implant dehiscence defects renders different results from soft-type block bone substitute in the aspect of hard tissue augmentation.

Material and Methods

Forty subjects, requiring GBR on dehiscence defect (≥3 mm in height) at implant 1st surgery were enrolled, and the patients were randomly assigned to either one of two groups- GBR with particulated, synthetic bone substitiute (particle group) or GBR with L-shaped soft-type block, synthetic bone substitute (block group). Clinical measurements of the defects (defect height and width) were performed at 1st surgery and 2nd surgery, and cone-beam computed tomographies (CBCT) were taken two times, immediately and at 6 months after the 1st surgery, for horizontal, vertical and oblique measurements of the grafted site. The operating time spent for GBR procedure was also measured.

Results

Complete defect coverage was found in 57.9% of block group (11 19) and 55.0% of particulated group (11 20), at 6 months. In clinical measuring, defect height significantly decreased at 6 months comparing to the baseline in both groups (P < 0.05), however, there was no significant difference between two groups (3.84 ± 2.45 mm decrease in block group vs. 3.78 ± 3.05 mm decrease in particle group). In radiographic assessment, both group demonstrated similar amount of horizontal bone gain at the level of implant shoulder at 6 months (P > 0.05). Mean operating time spent for GBR procedure in particle group was 12.9% longer compared to that of block group; nonetheless, the difference between two groups was not significant.

Conclusion and clinical implications

Within the limitation of this study, using L-shaped soft-type block, synthetic bone substitute in GBR showed comparable performance in peri-implant dehiscence defect resolution, compared to using particulated, synthetic bone substitute.