In this study, we immersed amorphous calcium phosphate (ACP) powder in biochemical buffer solutions and performed analysis of its solubility and phase transformation of the precipitate. After preparing ACP powder that contains no impurities, we used 4-(2-hydroxyethyl)-1-piperazinetethanesulfonic acid (HEPES) buffer, one of the good buffers, as a buffer solution and measured the amount of calcium ions eluted from ACP and other calcium phosphate crystals. ACP was immersed in the buffer solution at 5°C, 20°C, and 37°C, and the amount of eluted calcium ions was measured from 15 min to 24 h thereafter. The precipitated solid phase was analyzed using X-ray diffraction and its morphology was observed using transmission electron microscopy. The precipitation of hydroxyapatite (HAp) was observed after 15 min in HEPES buffer solution. Furthermore, in this experimental group, the precipitates of the sample incubated in HEPES buffer solution at 37°C for 24 h produced the largest HAp crystals. From these results we concluded that ACP immersed in HEPES buffer solution easily releases calcium ions and phosphate ions, and a rapid phase transformation to HAp occurs. Moreover, we assume that, in addition to the thermodynamic effect, the crystal growth of HAp is enhanced by the buffer solution.

The dental panoramic radiographs (PR) and lateral cephalographs (LC) of 140 subjects in the age group between 5 and 24 years were examined to evaluate the mandibular morphology in relation to gender and age. The examined films were divided into seven age groups. The bigonial width (BW), mandibular body height (MBH) and length (MBL), mandibular ramus width (MRW), height (MRH) and length (MRL), and gonial angle were recorded, measured and the data analyzed. Level of significance was set at 0.05. In our study the mean value of BW and MRW increased in both gender with increasing age up to age 17 years, then began decreasing. The anterior and posterior MBH and MBL increased with increasing age for both genders with statistically significant differences between the first and second groups (p< 0.05) and the fourth and fifth groups (p< 0.05) for anterior MBH, and between the third and fourth groups (p< 0.05) for posterior MBH and MBL (p< 0.05). MRH and MRL also increased with increasing age with statistically significant differences between the third and fourth (p< 0.05) and the fourth and fifth (p< 0.05) age groups for MRH and the fourth and fifth (p< 0.05) and fifth and sixth (p< 0.05) age groups for MRL. On the other hand, the gonial angle decreased with increasing age but without significant differences. Knowledge of mandibular growth is important factors for diagnosis and treatment planning in orthodontics as well as community medicine for monitoring the growth of children.

Adipose-derived mesenchymal stem cells (ASCs) have showed advantages in the source of therapeutic cells because of their paracrine function, multi-differentiation capacity, and easy access. Liposuction is an appropriate and safe method for obtaining adipose tissue, but little investigation exists regarding the impact of liposuction on the basic characteristics of ASCs. In this study, human ASCs were successfully isolated from liposuction and resected fat tissue. ASCs obtained via liposuction (Lip-ASCs) exhibited indiscriminate signatures when directly compared with resected fat tissue (Res-ASCs), including morphology, immunophenotype, viability, proliferation, and multi-directional differentiation potential. The comparison of multifaceted characteristics indicated that liposuction is an effective method to obtain and isolate ASCs with high quality, which is suitable for applications in basic research and clinical therapy.

The aim of this study was to identify genes that are prominently expressed in rat bone marrow cell-derived osteoblasts during the initial phase of low-intensity pulsed ultrasound (LIPUS) exposure. Bone marrow cells were obtained from three Sprague-Dawley rats (8-week-old, male), and cell cultures were prepared by suspension in osteogenic medium. After cultures were established, test cultures were exposed to LIPUS from the bottom of the cell culture plate for 15 min/d on days 1–4 (LIPUS group). LIPUS signals were transmitted at a frequency of 3 MHz and a spatial average intensity of 40 mW/cm². The control group was not exposed to LIPUS. On day 14, alizarin red S staining was performed to detect calcification. On day 4, total RNA was extracted from both cultures, hybridized to microarray slides, and the resulting data set was analyzed. Genes exhibiting a fold-change ≥2 and a p-value <0.05 (LIPUS vs. control) were identified as differentially expressed genes. Pathway analysis was performed on genes whose expression increased in the LIPUS group. The cellular areas stained with alizarin red S were significantly larger in the LIPUS group than in the control group on day 14. LIPUS exposure increased the expression of genes related to type II interferon signaling, and endochondral ossification was observed after 4 d of culture. The results demonstrated that LIPUS exposure activated the immune response and promoted osteoblast differentiation.

Patients with diabetes mellitus (DM) are at an increased risk of tooth loss compared to healthy individuals. Although studies human subjects suggest that diabetes control is affected by periodontitis, there is scarce mechanistic evidence supporting its biological plausibility. Therefore, using type 2 DM rat bone marrow mesenchymal stromal cells (BMMSCs) were incubated with four concentrations of glucose (5.5, 8.0, 12.0 or 24.0 mM), the effects of different glucose concentrations on BMMSCs stemness and osteogenesis were evaluated. High glucose concentrations decreased the fluorescence intensity of β-actin, STRO-1, CD73 and CD90. Moreover, cell proliferation decreased at high glucose concentrations. Alkaline phosphatase activity was decreased at 12.0 mM and 24.0 mM. In contrast, osteocalcin production and calcium deposition were considerably increased at 24.0 mM. Differences in the calcium/phosphate ratio associated with various glucose concentrations were similar to calcium deposition. The mRNA expression of Runx2 and inflammatory cytokines increased with increasing glucose concentration. The RANKL/OPG ratio decreased at high glucose concentrations. A high glucose concentration increased hard tissue formation, but the quality and stemness of the mineralized tissue decreased. Thus, hard tissue had a high risk of bone resorption in the case of uncontrolled diabetes even if periodontal treatment stabilized state of periodontitis for a moment.

In 2014, the American Association of Oral and Maxillofacial Surgery (AAOMS) recommended surgical treatment for medication-related osteonecrosis of the jaw (MRONJ) patients classified as Stage 3. In 2016, the Japanese position paper recommended surgical treatment classified as Stage 2. Some systematic review reported effectiveness of surgical treatment for MRONJ. However there is no concerted consciousness on the treatment methods of MRONJ patients in the present. This study aimed to retrospectively elucidate clinical outcomes of the surgical treatment of MRONJ patients under the same criteria. This study included 86 patients in 40 osteoporosis patients (5 men and 35 women, average age: 78.8 years) and 46 cancer patients (18 men and 28 women, average age: 67.7 years). The outcome was classified into two categories: Healing or No healing in each stage. Among 86 patients, MRONJ was found in 91 jaws, of which 69 jaws (75.8%) were surgically operated. Total healing rate of surgical treatment was 85.5%, and total healing rate of conservative treatment was 4.5%. It was suggested that surgical treatment for MRONJ had a high clinical response rate in all stages.

Onlay bone augmentation is a challenging field, especially in esthetic zones. In implant dentistry, labial bone loss is generally recovered through autologous bone and/or biomaterials. Dental pioneers have been applying a patient-own demineralized dentin matrix (DDM) for bone regeneration. The aim of this study was to histologically and radiologically evaluate horizontal bone augmentation on an anterior atrophic maxilla using an autograft of non-vital tooth-derived DDM for implant. A 56-year-old female patient presented with severe labial bone loss. Autologous DDM was immediately prepared for horizontal ridge augmentation. DDM blocks were fixed with titanium screws for lateral augmentation. DDM granules were grafted on the atrophic bone between the DDM blocks. Twelve months postoperatively, bone biopsy was performed from the implant placement point for histological observation. X-ray computed tomography (CT) was performed before and after the DDM graft surgery. Hematoxylin and eosin sections showed that new bones were directly generated on the DDM residue. CT images showed the original buccal bone lines and root-type and wall-type DDM. The grafted DDMs were clearly found on the original bone. The outlines in the 22nd region indicated an 8.11 mm horizontal width after the implant placements compared to 4.95 mm before the augmentation. Additionally, the width at the upper level increased from 3.38 mm to 5.92 mm. DDM scaffolds contributed to the horizontal bony support required to place the implants. The patient experienced therapeutic success with DDM immediate autograft and implant surgery.

Vascularized autologous bone grafts are widely used for mandibular reconstruction. There have also been numerous reports of occlusal reconstruction by placement of implants in the grafted bone following reconstruction of the mandible. However, the histological structure of the bone used for the graft is different from that of healthy mandibular bone, and the osseointegration process of implants placed in grafted bone is not clear. In this study, implants placed in reconstructions using grafted bone were assessed by measuring the implant stability quotient (ISQ), and their values were compared to those from implants in healthy mandibular bone. The subjects were 5 implants placed in the sites of mandibular reconstructions with vascularized fibula flaps. The controls were 54 implants placed in the molar region of healthy mandibles. All implant placements were carried out by a two-stage procedure, and the ISQs were measured at first-stage surgery and at second-stage surgery. The ISQ values thus obtained and the change in ISQ from first-stage surgery to second-stage surgery were examined statistically. There was no significant difference in the ISQ between the two groups at first-stage surgery, but the values of the ISQ and the change in ISQ were significantly greater in the mandibular reconstruction at second-stage surgery. This appears to be the result of histological differences between the reconstruction site and the healthy bone. The ISQ is an objective index of osseointegration of the implant. The present results suggest that observing changes in ISQ over time allows investigation of the usefulness of different types of bone grafts for implant therapy.

We have withdrawn following article.

“Synthesis of a Novel bFGF/nHAP/COL Bone Tissue Engineering Scaffold for Mandibular Defect Regeneration in a Rabbit Model” by Yue Cai, Xuexin Tan, Li Zhao, Ran Zhang, Tong Zhu, Yang Du and Xukai Wang in Journal of Hard Tissue Biology 27(1): 85-94, 2018.

This article has been withdrawn at the request of all the authors. This article reports that a fibroblast growth factor (bFGF) releasing nanometer hydroxyapatite (nHAP)/ collagen (COL) scaffolds promoted osteo-differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro and repaired bone defects in vivo. We have recently repeated the experiments and intended to research the mechanisms deeply. Unexpectedly, the results were opposite to this published article: bFGF releasing nHAP/ COL scaffolds promoted BMSCs proliferating not osteo-differentiating, the scaffolds didn’t significantly promote bone repair in rabbit mandibular defects neither. Similarly, some researches reported that bFGF exhibited no positive even inhibitory effects on bone formation. As these literatures demonstrated, the effects of bFGF in osteo-differentiation are controversial, which were dose and time dependent, and may be related to the variable origins and commitment states of cells in applied in vitro and in vivo models. Low concentration bFGF might have osteostimulative effects, while high concentration had inhibitory effects. Furthermore, bFGF at the same dose exhibited opposite effects when combined with hydroxyapatite or demineralized bone matrix^1-7). Recent researches preferred to apply bFGF together with bone morphogenetic proteins (BMPs) or transforming growth factor beta (TGF-β) to enhance osteogenic efficiency of the latter^8-11). Besides, researchers developed new scaffolds that can alleviate the osteogenesis-inhibitory effects of bFGF¹²⁾. We reviewed our own experiments, the contrary between repeated operations may rise from the instable and uncontrollable release of bFGF from the nHAP/ COL scaffolds. We plan to improve the preparation process to achieve precise release of bFGF, which can realize repeatability of the experiments. Under these circumstances, we believe that the most responsible course of action is to withdraw this current paper. We sincerely apologize to the scientific community for any inconvenience resulted from the publication and withdrawal this article.