Core Ossification of Bone Morphogenetic Protein-2-Loaded Collagenated Bone Mineral in the Sinus

Effects of Polydeoxyribonucleotide (PDRN) on Endosinus Bone Regeneration Following Sinus Floor Elevation: An Experimental In Vivo Pilot Study

OBJECTIVE

To determine the effect of polydeoxyribonucleotide (PDRN) on endosinus bone regeneration in a rabbit sinus model at sequential healing time points.

MATERIALS AND METHODS

Eighteen New Zealand white rabbits were used. Bilateral sinus floor elevation (SFE) was performed. Two groups were randomly assigned to each sinus: (1) test group, in which SFE was performed using collagenated bone substitute material soaked with PDRN (concentration 2.0 mg/mL, dose 0.5 mL), and (2) control group, in which SFE was performed using collagenated bone substitute material only. The experimental animals were sacrificed at 2, 4, and 8 weeks (n = 6 at each healing time point). Microcomputed tomography (micro-CT), histologic, and histomorphometric analyses were performed.

RESULTS

The micro-CT analysis revealed statistically significant increases in the mineralized tissue volume between 4 and 8 weeks (p < 0.05). Histologically, no specific intergroup difference was found in the pattern of new bone formation. Histomorphometrically, the area of newly formed bone (NB) was larger in the test group than in the control group at all healing time points (1.4 vs. 1.2 mm2 at 2 weeks, 3.4 vs. 1.9 mm2 at 4 weeks, and 5.7 vs. 4.5 mm2 at 8 weeks; median value), but the difference was statistically significant only at 4 weeks (p < 0.05). NB in set regions of interest (ROI_C, ROI_W, and ROI_M) tended to be greater in the test group than in the control group without statistical significance (p > 0.05).

CONCLUSIONS

PDRN appeared to enhance new bone formation at all healing time points, but the improvement was statistically significant only at 4 weeks.

Vertical bone augmentation using collagenated or non-collagenated bone substitute materials with or without recombinant human bone morphogenetic protein-2 in a rabbit calvarial model

PURPOSE

The aim of this study was to determine 1) the bone-regenerative effect of porcine bone block materials with or without collagen matrix incorporation, 2) the effect of a collagen barrier, and 3) the effect of adding recombinant human bone morphogenetic protein-2 (rhBMP-2) to the experimental groups.

METHODS

Four treatment modalities were applied to rabbit calvaria: 1) deproteinized bovine bone mineral blocks (DBBM), 2) porcine bone blocks with collagen matrix incorporation (PBC), 3) porcine bone blocks alone without collagen matrix incorporation (PB), and 4) PBC blocks covered by a collagen membrane (PBC+M). The experiments were repeated with the addition of rhBMP-2. The animals were sacrificed after either 2 or 12 weeks of healing. Micro-computed tomography (micro-CT), histologic, and histomorphometric analyses were performed.

RESULTS

Micro-CT indicated adequate volume stability in all block materials. Histologically, the addition of rhBMP-2 increased the amount of newly formed bone (NB) in all the blocks. At 2 weeks, minimal differences were noted among the NB of groups with or without rhBMP-2. At 12 weeks, the PBC+M group with rhBMP-2 presented the greatest NB (P<0.05 vs. the DBBM group with rhBMP-2), and the PBC and PB groups had greater NB than the DBBM group (P>0.05 without rhBMP-2, P<0.05 with rhBMP-2).

CONCLUSIONS

The addition of rhBMP-2 enhanced NB formation in vertical augmentation using bone blocks, and a collagen barrier may augment the effect of rhBMP-2.