The rabbit tooth model may be useful for experimental in-vivo studies on delayed replantation, subsequent ankylosis, osseous replacement and infraposition.

Removal of PDL prior to delayed replantation may result in some initial protection of the cementum during the first few weeks. However, over longer times there seems to be neither protection of the dentin from ankylosis and osseous replacement, nor any influence on the rate of replacement resorption.

The purpose of this study was to evaluate bone healing in calvarial defects using two bone graft substitute materials; biphasic beta‐tricalcium phosphate/hydroxyapatite in hydrogel (ß‐TCP/HA) versus composite non‐demineralized xenogenic dentin with ß‐TCP/HA mixture. Full thickness critical‐sized defects were created bilaterally in 10 New Zealand male rabbits. Seven defects were left empty, six filled with biphasic tricalcium phosphate putty, and seven were filled with composite non‐demineralized xenogenic dentin with biphasic tricalcium phosphate. Animals were sacrificed at eight weeks postoperatively and the healing of the biomaterial‐filled defects was compared radiographically and by histomorphometry. Micro‐computed tomography (μCT) was utilized to analyze the osteogenesis and healing patterns of the defects. Quantitative analysis of volume fraction (%) of the newly formed bone and remaining graft material (FV=filling volume/TV=tissue volume) and mean intensity [HU] in the defects were evaluated. Defects filled with composite dentin with biphasic tri‐calcium phosphate showed volume fraction (FV/TV) in the order of 55.81% ± 17.72%, whereas defects filled with only biphasic tricalcium phosphate showed a fraction of 39.84% ± 16.06%, which represent the ratio of remaining graft material and new bone formation to the tissue volume. The empty negative control defects showed a volume fraction of 19.14% ± 8.787%. Histological analysis showed significant percentage increase in bone formation and residual graft with the composite Dentin/ß‐TCP group after 8 weeks. The findings suggest that composite xenogenic dentin with biphasic tricalcium phosphate showed improved osteogenesis when compared to biphasic tricalcium phosphate without the addition of non‐demineralized dentin. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 773–782, 2019.