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The present study aimed to investigate whether bone morphogenetic protein-2 (BMP-2) was involved in the repair of mandibular defects using polyether-ether-ketone biphasic bioceramic (PEEK-BBC) composites in rabbits. PEEK-BBC composites with abundant and interconnected pores were prepared by calcination and characterized by scanning electron microscope. A mandibular defect model in rabbits was established using dental grinder to produce a square hole. A total of 60 rabbits were divided into four groups: Control, sham, surgery, and PEEK. In the PEEK group, the holes were filled with the PEEK-BBC composite stents. In the surgery group, the holes were produced but not filled with the composite stents. In the sham group, only the molar grooves were exposed and grinding was not performed. Animals without any treatment served as the control group. The success rate of model establishment was 100%. At 4, 8, and 16 weeks after the model was established, samples were collected from the molding sites. Bone repair was evaluated by H&E staining and Goldner trichrome staining. Bone structures in both control and sham groups were intact. A small number of osteocytes were observed in the surgery group. However, in the PEEK group, osteocytes were already evidently present in the composites at 4 weeks after surgery. At 8 and 16 weeks, there were large numbers of osteocytes in the pores of the composites. The mRNA and protein expression levels of BMP-2 were determined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. The mRNA and protein expression levels of BMP-2 between the control and sham groups were similar and were continuously stable. However, following defect treatment, BMP-2 mRNA and protein expression was upregulated, which was enhanced by the PEEK-BBC composites. In conclusion, PEEK-BBC composites promoted the growth of osteocytes and repaired mandibular defects in rabbits, potentially via the upregulation of BMP-2 expression.

BackgroundAssociations between interleukin-8 (IL-8) gene polymorphisms and periodontitis susceptibility have been investigated in many published studies, but the conclusions are still inconsistent. Therefore, we performed this systematic review and meta-analysis to review which polymorphisms have been researched and to obtain a precise result of the same polymorphism from different studies.ResultsFinally 10 publications involving 1938 patients and 1569 controls were yielded, including 12 polymorphisms. Six studies investigated rs4073 polymorphism; two focused on rs2227306 and rs2227307; two referred to rs2227532 and T-738A; one detected rs2230054, rs1126579 and rs1126580; one inspected A2767T, T11722T2 and C1633T, and one for rs2234671 polymorphism. Of them, IL-8 C1633T and rs1126580 polymorphisms showed positive association while the other ten polymorphisms revealed negative results.Materials and methodsA comprehensive literature search from PubMed, Web of Science, and Chinese National Knowledge Infrastructure was conducted for all potentially relevant studies published before January 2, 2017. Two authors selected the studies and extracted data. The pooled analysis was conducted using the RevMan 5.1 software if a polymorphism was reported by two or more studies.ConclusionsBased on current evidence, the IL-8 rs4073, A2767T, T11722T2, rs2234671, rs2230054, rs1126579, rs2227306, rs2227307, rs2227532, and T-738A polymorphisms were not associated with periodontitis susceptibility; the IL-8 C1633T and rs1126580 polymorphisms were associated with increased risk of periodontitis.