Bone regeneration in the presence of a synthetic hydroxyapatite/silica oxide-based and a xenogenic hydroxyapatite-based bone substitute material

Objectives A comparison of synthetic hydroxyapatite/silica oxide, xenogenic hydroxyapatite-based bone substitute materials with empty control sites in terms of bone regeneration enhancement in a rabbit calvarial four non-critical-sized defect model. Methods In each of six rabbits, four bicortical calvarial bone defects were generated. The following four treatment modalities were randomly allocated: (1) empty control site, (2) synthetic hydroxyapatite/silica oxide-based (HA/SiO) test granules, (3) xenogenic hydroxyapatite -based granules, (4) synthetic hydroxyapatite/silica oxide -based (HA/SiO) test two granules. The results of the latter granules have not been reported due to their size being three times bigger than the other two granule types. After 4 weeks, the animals were sacrificed and un-decalcified sections were obtained for histological analyses. For statistical analysis, the Kruskal-Wallis test was applied (P < 0.05). Results Histomorphometric analysis showed an average area fraction of newly formed bone of 12.32 +/- 10.36% for the empty control, 17.47 +/- 6.42% for the xenogenic hydroxyapatite -based granules group, and 21.2 +/- 5.32% for the group treated with synthetic hydroxyapatite/silica oxide -based granules. Based on the middle section, newly formed bone bridged the defect to 38.33 +/- 37.55% in the empty control group, 54.33 +/- 22.12% in the xenogenic hydroxyapatite -based granules group, and to 79 +/- 13.31% in the synthetic hydroxyapatite/silica oxide -based granules group. The bone-to-bone substitute contact was 46.38 +/- 18.98% for the xenogenic and 59.86 +/- 14.92% for the synthetic hydroxyapatite/silica oxide-based granules group. No significant difference in terms of bone formation and defect bridging could be detected between the two bone substitute materials or the empty defect. Conclusion There is evidence that the synthetic hydroxyapatite/silica oxide granules provide comparable results with a standard xenogenic bovine mineral in terms of bone formation and defect bridging in non-critical size defects. To cite this article:Kruse A, Jung RE, Nicholls F, Zwahlen RA, Hammerle CHF, Weber FE. Bone regeneration in the presence of a synthetic hydroxyapatite/silica oxide -based and a xenogenic hydroxyapatite -based bone substitute material.Clin. Oral Impl. Res. 22, 2011; 506-511doi: 10.1111/j.1600-0501.2010.02039.x.