Background: Horizontal bone augmentation may be required previously to implants placement. Guided Bone Regeneration (GBR) may be performed, using a mix of particulate allograft (DFDBA 300-500 and 500-1000 μm), platelet concentrates (A-PRF) and tent-screws (1.2 mm diameter) in combination with a tension-free muco-periosteal flap closure technique may be used.

Aim/Hypothesis: To evaluate bone gain obtained with this surgical technique, in order to find out if this technique allows a satisfying bone gain, as compared to other techniques of bone augmentation.

Materials and Methods: A prospective clinical study was conducted. 23 patients were included. Exclusion criteria were: minor patients, pregnant women, smokers, infectious or uncontrolled systemic diseases, radiotherapy or chemotherapy, treatment altering bone quality. A total of 33 grafts were performed. Qualitative variables were collected: location according to the dental arch (maxillary or mandibular), quadrant (1 to 4), extent of the edentation (multiple or 1), type of the edentation (terminal or intercalate), use of a collagen membrane or not. Clinical complications were recorded. Measurements were made on the pre-operative (T0) and the post-operative (T1) scanners. The gain was obtained by calculating the difference between the measures made on T0 and T1. A test of concordance between the two sets of measures was conducted. A Student T-test and a Bartlett test were used to determine the significance of the difference between means and variances. For qualitative variables, a Mann-Whitney test was used.

Results: The correlation coefficient (r = 0.690) proved a strong relationship between the two series of measurements. The Student T-test (P = 0.91) and the Bartlett test (P = 0.59) determined respectively the equality of means and variances between operators. For the 33 grafted sites, mean bone gain was 3.78 ± 1.12 mm. No mucosa dehiscence was observed. Only 1 local infection of the grafted site were observed, which was solved by antibiotherapy. Bone gain was higher when the graft was located on the maxilla (3.79 ± 1.01 mm) compared to the mandible (2.90 ± 1.20 mm). This result was statistically significant (P-value = 0.034). Bone gain was also significantly higher when edentulous sites were intercalated (3.83 ± 0.942 mm) compared to the distal edentulous sites (2.97 ± 1.24 mm), (P-value = 0.047). The analysis of the other variables (quadrant, extent of the edentation, use of a collagen membrane) did not show any statistically significant difference in term of bone gain.

Conclusions and Clinical Implications: Guided Bone Regeneration (GBR) using a mix of particulate allograft (DFDBA 300-500 and 500-1000 μm), platelet concentrates (A-PRF) and tent-screws (1.2 mm diameter) in combination with a tension-free muco-periosteal flap closure technique is a safe procedure that can achieve a horizontal bone gain of 3.78 ± 1.12 mm on average.

Keywords: Alveolar Ridge Augmentation, Guided bone regeneration, Particulate allograft, Platelet concentrates, Tent-screws