A survey on iodine nutrition status of pregnant women in Wuhan from 2016 to 2020 / 中华地方病学杂志

Objective:To understand the iodine nutrition status of pregnant women in Wuhan, and to provide a basis for guiding pregnant women to supplement iodine scientifically and adjust the prevention and control strategy of iodine deficiency disorders.Methods:From May 2016 to September 2020, each district of 13 administrative districts in Wuhan was divided into 5 areas according to east, west, south, north and middle. One township (street) was selected from each area, and 20 pregnant women were selected from each township (street). Edible salt and urine samples were collected to detect the contents of salt iodine and urinary iodine. Salt iodine was determined by direct titration, Sichuan salt and other fortified edible salt by arbitration method; urinary iodine was detected by arsenic-cerium catalytic spectrophotometry. Salt iodine and urinary iodine were analyzed according to different years, regions (central and far urban areas), age [low age (< 25 years old), appropriate age (25 - 34 years old), old age (≥35 years old)], and pregnancy [early pregnancy (< 13 weeks), middle pregnancy (13 - 27 weeks), and late pregnancy (28 - 40 weeks)].Results:A total of 5 200 edible salt samples from pregnant women's homes were collected, and the median salt iodine was 24.41 mg/kg. Among them, there were 32 non-iodized salts, 4 962 qualified iodized salts, and 206 unqualified iodized salts. The coverage rate of iodized salt was 99.38% (5 168/5 200), and the consumption rate of qualified iodized salt was 95.42% (4 962/5 200). A total of 5 200 pregnant women's urine samples were tested, and the median urinary iodine was 161.24 μg/L. Urinary iodine < 150 μg/L was found in central urban area, early pregnancy, middle pregnancy, low age and old age pregnant women in 2016 (141.74, 149.00, 132.34, 135.17, 121.00 μg/L); in early pregnancy, middle pregnancy and old age pregnant women in 2017 (128.00, 149.00, 141.41 μg/L); and in middle pregnancy and old age pregnant women in 2020 (148.95, 138.00 μg/L), which was at iodine deficiency level.Conclusions:Pregnant women in Wuhan are generally at iodine appropriate level, but close to the lower limit of the appropriate value, some pregnant women are at risk of iodine deficiency. It is still necessary to pay close attention to iodine nutrition status of pregnant women, and advocate pregnant women to eat qualified iodized salt actively.

Bone morphogenetic protein 7 mediates stem cells migration and angiogenesis: therapeutic potential for endogenous pulp regeneration / 国际口腔科学杂志·英文版

Pulp loss is accompanied by the functional impairment of defense, sensory, and nutrition supply. The approach based on endogenous stem cells is a potential strategy for pulp regeneration. However, endogenous stem cell sources, exogenous regenerative signals, and neovascularization are major difficulties for pulp regeneration based on endogenous stem cells. Therefore, the purpose of our research is to seek an effective cytokines delivery strategy and bioactive materials to reestablish an ideal regenerative microenvironment for pulp regeneration. In in vitro study, we investigated the effects of Wnt3a, transforming growth factor-beta 1, and bone morphogenetic protein 7 (BMP7) on human dental pulp stem cells (h-DPSCs) and human umbilical vein endothelial cells. 2D and 3D culture systems based on collagen gel, matrigel, and gelatin methacryloyl were fabricated to evaluate the morphology and viability of h-DPSCs. In in vivo study, an ectopic nude mouse model and an in situ beagle dog model were established to investigate the possibility of pulp regeneration by implanting collagen gel loading BMP7. We concluded that BMP7 promoted the migration and odontogenic differentiation of h-DPSCs and vessel formation. Collagen gel maintained the cell adhesion, cell spreading, and cell viability of h-DPSCs in 2D or 3D culture. The transplantation of collagen gel loading BMP7 induced vascularized pulp-like tissue regeneration in vivo. The injectable approach based on collagen gel loading BMP7 might exert promising therapeutic application in endogenous pulp regeneration.

Development of new technology in periodontal tissue engineering / 中华口腔医学杂志

The loss of periodontal support tissues might cause movement or finally loss of the teeth affected, impair furthermore the pronunciation and mastication functions, and even result in a series of physiological and psychological problems. Tissue engineering, as a technology to remodel missing tissues or organs and functional reconstruction, has achieved gratifying progress in regeneration of periodontal tissues. However, conventional construction methods have some deficiencies for functional periodontal reconstruction. In recent years, with the progress of tissue engineering technology, a series of new techniques and methods, such as cell sheet technology, decellular technology, electrospinning technology and three-dimensional printing, has been applied in tissue engineering bringing new hope for the regeneration of periodontal tissues. In this review article, the recent progress achieved in the field of periodontal tissue engineering and application of modern technology are summarized to make a brief exposition and to explore the future development of periodontal regeneration.

Tooth and its supporting tissues regeneration using functional tooth modules / 中华口腔医学杂志

Stem cell based generation of functional tissue modules is becoming a hotspot in the field of tissue regeneration. These functional tissue modules, which can be prepared through a variety of ways, including self-organization of stem cells, cell sheets, electrospinning and bio-printing, can serve as the basic unit and be assembled to form larger tissues and organs. This new technology can be a break-through to address current issues in tissue regeneration and further promote the translational use of regenerated tissues/organs. Construction of functional tooth modules is still in its early stage, where the stem cell source, preparing method and strategy of translational use are not clearly defined yet. How to construct the functional tissue module through the existing technology still needs further study. Here, we would like to share our current understanding and thoughts on constructing strategies and potential clinical application of functional tooth modules including dental pulp, periodontal tissue and tooth root, and hope it could shed new lights on the regeneration of tooth.

Treated dentin matrix enhances proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The effect of treated dentin matrix (TDM) to the proliferation and osteogenesis differentiation of bone marrow mesenchymal stem cells (BMSCs) is evaluated in vitro.</p><p><b>METHODS</b>TDM leaching solution was prepared by dentine particles suffering from gradient demineralization. Human BMSCs were isolated and cultivated, and subsequently cultivated in the TDM leaching solution. The proliferation of BMSCs was detected by CCK-8. The osteogenesis-related proteins, including collagen type I (Col I) and runt-related transcription factor-2 (Runx2), were extracted and detected by Western blot after a 7-day culture.</p><p><b>RESULTS</b>Compared with the control group and hydroxyapatite (HA)/β-tricalcium phosphate (βTCP) group, the proliferation of BMSCs cultivated in TDM leaching solution was significantly improved. The expression of Col I and Runx2 obviously increased after the 7-day cultivation in TDM leaching solution.</p><p><b>CONCLUSION</b>TDM can promote the proliferation and osteogenesis differentiation of BMSCs, implying the feasibility of the application in bone tissue engineering.</p>

Corrosion resistant properties of different anodized microtopographies on titanium surfaces / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies.</p><p><b>METHODS</b>Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid.</p><p><b>RESULTS</b>Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr.</p><p><b>CONCLUSION</b>Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.</p>

Effects of different fibrin glue combination modes on the proliferation and viability of dental follicle cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study explores the effects of different fibrin glue combination modes on the survival, proliferation, and apoptosis of dental follicle cells (DFCs), as well as to evaluate the feasibility and effectiveness of fibrin glue as transplantation material.</p><p><b>METHODS</b>The membranes of surviving DFCs were marked using 3,3'-dioctadecyloxa carbocyanine perchlorate (DIO), and the cell number was counted by using ImageJ2x software. The apoptotic cells were marked with prodium iodide (PI).</p><p><b>RESULTS</b>Compared with that of the 3D-2 and 2D-1 groups, the degradation speed of the 3D-1 group was the slowest. DFCs could survive and grow well in fibrinogen with a concentration of 15 mg · mL⁻¹ supplemented with thrombin with a concentration of 2 U · mL⁻¹. In particular, the 3D-1 combination mode was significantly conducive to cell proliferation and stretching.</p><p><b>CONCLUSION</b>Fibrin glue can be used as an effective cell transplantation material. The different combination modes have certain effects on cell proliferation. The 3D-1 combination mode is more conducive to the survival and proliferation of DFCs than other modes.</p>

Biomechanical evaluation and optimal design of two parameters of dental implant with arbitrarily adjusted angles / 中国组织工程研究

BACKGROUND:Oversize stress of a dental implant and its surrounding tissue is the main factor to affect the long-term use of dental implants. So, the reasonable and precise design of implant shape is one of the important methods of prolonging the life span of dental implants. OBJECTIVE:To make the optimal analysis and design of the diameters of connector screw and central screw of the adjustable-angle dental implant invented in the earlier stage. METHODS: The finite element analysis model of the edentulous mandible with adjustable-angle dental implant was established by software Pro/E 5.0, Mimics 10.0 and ANSYS Workbench 14.5. The maximum equivalent stress of dental implant-edentulous mandibular model was analyzed. RESULTS AND CONCLUSION:The maximum equivalent stress of dental implant-edentulous mandibular model

Platelet-rich plasma effects on grainy fat transplantation / 中国组织工程研究

BACKGROUND:The higher long-term absorption rate greatly influence the widely application of fat transplantation. Platelet-rich plasma contains a high concentration of growth factors, which benefits to the tissue healing and regeneration. OBJECTIVE:To observe the effects of platelet-rich plasma on grainy fat transplantation and to investigate the mechanisms preliminarily. METHODS:Ten 6-week-old nude mice were prepared. The right or left dorsal subcutaneous tissues were randomly selected as the platelet-rich plasma group (0.5 mL fat granule+0.1 mL platelet-rich plasma), and the contralateral side was regarded as the control group (0.5 mL fat granule+0.1 mL phosphate-buffered saline). At 10 and 90 days after implantation, five nude mice were selected from each group, and then the mice were sacrificed to obtain the grafts in each group for general appearance observation, volume determination and histological detection. Furthermore, we isolated adipose-derived stem cells from human subcutaneous fat tissue during the in vitro experiment. Cel counting kit-8 and real-time PCR were used to evaluate the influence of platelet-rich plasma on adipose-derived stem cel proliferation and adipogenic differentiation in vitro, respectively. RESULTS AND CONCLUSION:Comparison of the grafts obtained at 10 and 90 days after implantation, the residual volume in the platelet-rich plasma group was significantly larger than that in the control group (P<0.05), Moreover, more normal adipocytes and capil ary formation were observed in the platelet-rich plasma group (P<0.05). For in vitro experiment, platelet-rich plasma could significantly improve adipose-derived stem cel proliferation, and the expressions of adipogenic-related genes were up-regulated in platelet-rich plasma-induced adipose-derived stem cells. Al results demonstrate that platelet-rich plasma can improve the survival of fat grafts,which might be closely related to that platelet-rich plasma can promote the proliferation and adipogenic differentiation of adipose-derived stem cells and the revascularization in grafted fat tissue.

Quality assessment on reports of randomized controlled trials of oral and maxillofacial surgery in China / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the report quality of randomized controlled trials (RCT) of oral and maxillofacial surgery in China during 2000-2009.</p><p><b>METHODS</b>A comprehensive electronic search was carried out through Chinese Biomedical Literature Database (CBM), VIP Database for Chinese Technical Periodicals (VIP) and China National Knowledge Infrastructure (CNKI), and 19 kinds of journals of stomatology in China were also hand-searched. We identified RCT published between 2000 and 2009, and classified into oral and maxillofacial surgery and labeled "random" and assessed the quality of these reports using the consolidated standards of reporting trials (CONSORT) statement.</p><p><b>RESULTS</b>53 RCT articles were included. Reporting quality of the 53 articles was not high and the CONSORT score was 8.2 +/- 2.5.</p><p><b>CONCLUSION</b>The reporting quality of RCT of oral and maxillofacial surgery in China is poor. The CONSORT statement should be used to standardize the reporting of RCT.</p>

Effect of insulin-like growth factor Ⅰ and basic fibroblast growth factor on proliferation and differentiation of human dental papilla mesenchymal cells / 中国组织工程研究

BACKGROUND: Previous research has indicated that both insulin-like growth factor Ⅰ (IGF-Ⅰ) and basic fibroblast growth factor (bFGF) play an important role in cell proliferation and differentiation. However, the effect on biological characteristics of human dental papilla mesenchymal cells (hDPMCs) still remains unclear. OBJECTIVE: To research the effect of IGF-Ⅰ and bFGF on the proliferation and differentiation of hDPMCs.METHODS: hDPMCs were isolated and cultured in DMEM/F12 culture media containing 1% or 10% fetal bovine serum. The fourth-passaged hDPMCs were incubated in culture media containing 0, 0.1, 1, 10 and 100 μg/L bFGF and 0, 25, 50, 75 and 100 μg/L IGF-Ⅰ(0 μg/L as control group), respectively. At 96 hours after culture, proliferative activity was measured with MTT assay. The corresponding growth factor culture media were used in 10 μg/L bFGF group, 100 μg/L IGF-Ⅰgroup, bFGF + IGF-Ⅰ group, and control group, respectively. At days 1, 3, 5, and 7 after culture, the proliferative activity was detected using MTT assay, and alkaline phosphatase (ALP) activity was measured using modified enzyme kinetics method. RESULTS AND CONCLUSION: At the 0-100 μg/L mass concentration scope, both bFGF and IGF-Ⅰcould accelerate proliferation of hDPMCs, and the proliferation ability of bFGF was superior to that of IGF-Ⅰ; moreover, the combination of bFGF and IGF-Ⅰcaused a synergetic action to proliferation of hDPMCs. The maximal valid concentration of bFGF was 10 μg/L, and the maximal action concentration of IGF-Ⅰwas 100 μg/L. At 0-7 days, the effect of bFGF on the ALP activity of hDPMCs was not obvious, but the effect of IGF-Ⅰon ALP activity of hDPMCs became greater with the time passing; furthermore, the combination of bFGF and IGF-Ⅰcould generate a synergetic action on increasing the ALP activity.

Effects on the expression of NF-kappaBp65 of osteoblast-like cell under stretch load with different daily loading times / 生物医学工程学杂志

The purpose of this study was to investigate the effect on the expression of NF-kappaBp65 of osteoblast-like cell under stretch load with the same amplitude but different daily loading times. The osteoblast-like cells MG-63 were passage cultured and stretched by the four-point-bend loading device; based on the daily loading times, the osteoblast-like cells were randomly divided into four groups. The first was the control, the others were stretched with mechanical tension with the same amplitude of 2,000 mu strain and at the same frequency of 0.5 Hz., but the daily loading times were 1 time/d, 2 times/d, 4 times/d differently for each group, the periods of mechanical tension applied to the cells of the three groups were all 60 min/d and lasted for 2d total. After the cells being streteched, the expression levels of NF-kappaBp65 of the osteoblast-like cells of the three groups and control group were investigated by using the techniques of immunohistochemistry, and were compared with each other. The results showed that the positive expression ratios of the four groups were different significantly; the positive expression ratio of the control was lower than those of the other three groups; the positive expression ratio of the 4 times/d group was higher than those of the other two stretched groups; the positive expression ratio of the 2 times/d group was higher than that of the 1 time/d group. The results suggested that when the osteoblast-like cell was under the stretch load with different daily loading times but the same amplitude, the expression ratio of NF-kappaBp65 in the cell increased with the rising of the stimulating times. It means that the mechanical strain with high daily loading times could promote the transcriptional level of osteoblast-like cell more effectively.

Progress in the materials, design and related technique clinical application of temporomandibular joint prosthesis / 中国组织工程研究

OBJECTIVE:To summarize the materials, design, fit-shape and fixation techniques and clinical application of temporomandibular joint (TMJ) prosthesis.DATA SOURCES: An online search was undertaken to identify English articles about TMJ prosthesis published in Pubmed database from January 1998 to December 2006 using the key words of "temporomandibular joint, joint prosthesis".STUDY SELECTION: The collected literatures about TMJ prosthesis were sorted, and those with good pertinence were selected. For the literatures of the same field, those published recently or in authorized journals were selected.DATA EXTRACTION: Totally 69 literatures were collected, 28 were enrolled, and the other 41 were excluded, including 23 were irrelative with the aim of this study, and 18 were repetitive studies.DATA SYNTHESIS: Joint prosthesis is one of the fields that develop the fastest in orthopedic surgery in recent 30 years.TMJ replacement aims to enhance the function of TMJ, alleviate pain, and prevent serious complication. With the rapid developments of material science, tissue engineering, joint biomechanics and other related subjects, TMJ prosthesis has been significantly improved in the materials, design, fit-shape and fixation techniques. People have developed from simply imitating the outline form and mechanical motor of TMJ to pay more attention to its pathological function. It is very significant to trace the new progress in hip prosthesis and knee joint, and apply the good outcomes in the design and manufacture of TMJ prosthesis.CONCLUSION: Prosthetic material plays leading and promoting roles in the development of joint prosthesis, good design,fit-shape and fixation are the necessary conditions for prosthesis to act its role, and it is also necessary to investigate joint biomechanics. TMJ prosthesis should be further investigated, and it has good prospect.

Cultivation and morphological characteristics of rat adipose tissue-derived vascular endothelial cells in vitro / 生物医学工程学杂志

The subcutaneous adipose tissue from the inguen of four Sprague-Dawley rats was obtained, then digested with one volume of collagenase type I and cultured with BGJb medium. The obtained adipose stromal cells were induced in human endothelial-SFM for 7 d. The cells were observed under inverted microscope every day and identified by transmission electron microscope and immunocytochemical staining with factor VIII antigen. The results showed the induced cells uniformly had characteristic cobblestone morphology of endothelial cells. Factor VIII antigen staining was positive in cytoplasm. Under transmission electron microscope, the cells displayed many finger like microvilli and numerous lysosomes, mitochondria, a few coarse endoplasmic reticulum and Weibel-Palade bodies. The characteristics of the rat adipose tissue-derived endothelial cells were consistent with those of vascular endothelial cells derived from other tissues. It seems that subcutaneous adipose tissue may represent a new alternative source of endogenous vascular endothelial cells.

The reconstruction of bioengineer active corneal stroma and its biocompatibility study / 生物医学工程学杂志

This paper aims to explore the biocompatibility of bioengineer active corneal stroma (BACS), as the biological carrier for cornea reconstruction, to provide the basis for future study on clinic application. The cells and immunogenic components of cornea stroma were removed through different extract methods. A complex of functional corneal stroma cells and acellular corneal stroma was used to reconstruct BACS. Their morphological characteristics and ultrastructures were observed with transmission electron microscope. The complex was grafted into interlamellar stromal pockets. Cells were labeled by BrdU to examine the survival and conversion after grafting. The cells could survive and proliferate in acellular corneal stroma. All the nuclei of the corneal stromal cells showed positive labeling with BrdU in the BACS. After 4 weeks, BACS became transparent; after 8 weeks, the bioengineer active cornea stroma was fully reconstructed.

Development of a functional mandibular model / 生物医学工程学杂志

This study was conducted to establish a functional mandibular biomechanical model for use in the follow-up biomechanical study of the integrated and fractured mandible. The integrated and dry human mandible was used, and the corresponding maxilla and cranial base was duplicated by resin and plaster. 2-mm silicon rubber was used for simulation of the temporomandibular joint (TMJ) disc. A simulated TMJ and physiological mandibular model was developed by four pairs of muscular loadings (Masseter= 180 N, Temporalis = 190 N, Medial Pterygoideus = 120 N, Lateral Pterygoideus = 40 N) in each muscular center, and the functional loading corresponding with physiological condition was reflected and simulated more realistically when compared with that of the previously reported mandibular models which were developed by occlusion loading or by only one pair of muscles loading. In summary, we have established a functional mandibular model which can be used to analyze the biomechanical behavior in various functional conditions.

The effect of fluid shear stress on the NO synthesis of rat osteoblast-like cells / 生物医学工程学杂志

This study sought to elucidate the function of NO during the signal transduction wherein fluid shear stress regulates the proliferation and differentiation of osteoblast cells. The isolated rat osteoblast-like cells were exposed to fluid shear stress 12 dyn/cm2 for 5, 10, 15, 30, 60 and 120 min respectively with the use of a flow chamber. The NO release was examined. After the exposure to fluid shear stress, the NO synthesis of rat primary osteoblast-like cells increased significantly (P<0.05) when compared with the control. After 60 minutes of exposure, the release of NO began to increase significantly (P<0.05), but no significant increase as such was seen in the control (P>0.05). NO synthesis may be one of the signal transduction pathways which transduce the fluid shear stress into osteoblast cells. In early stage, it may be induced by cNOS and in late stage by iNOS.

Experimental study on the fabrication of bioactive membrane for inducing bone regeneration / 生物医学工程学杂志

The aim of this study was to develop a bioactive membrane for inducing bone regeneration. The membrane was composed of polylactic acid, collagen, recombinant human bone morphogenetic protein-2 (rhBMP-2). The PLA + collagen + rhBMP-2 membrane was fabricated by solvent-casting and cool-drying. The mechanic properties of this compound membrane were tested. The two surfaces of membrane were observed by SEM. Degradability of PLA was evaluated by SEM observation and molecular weight measure in vitro and in vivo. The compound membranes were implanted in rabbit muscles. The samples were obtained when animals were sacrificed at different periods: 2 weeks, 1, 2, 3, 6 months after surgery. The biodegradability and biocompatibility of the membrane were evaluated. The heterotopic bone inducing activity of BMP was identified. The results indicated that the strength at extension to failure of the compound membrane was 36.4MPa at 2.3% strain. The compound membrane was found bearing active factor on its coarse side, which can induce bone regeneration. After implantation in vivo, the membrane maintained the structure for three months and degraded in 6 months. Based on histological analysis, there was no obvious inflammation. Heterotopic bone was induced. We could conclude that the PLA + collagen + rhBMP-2 membrane is an absorbable compound membrane that possesses good biocompatibility, adequate mechanic properties and excellent property of bone induction. It could be applied as an ideal membrane for inducing bone regeneration.

A study on puncturing the temporomandibular joint cavity of rabbits and withdrawing synovia / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to study the methods of how to puncture the temporomandibular joint (TMJ) cavity of rabbits and get the synovia.</p><p><b>METHODS</b>The authors punctured joint cavity and withdrew the synovia from bilateral TMJ cavities of 12 New Zealand rabbits with different methods, such as the traditional puncture method, improved puncture, puncture under X ray, puncture guided by ultrasonography and spiral CT, and withdrawing synovia by micropump.</p><p><b>RESULTS</b>Only one cavity was successfully punctured using the traditional puncture method. A total of 4 cases were successfully punctured using the improved method. X ray and ultrasonography did not locate the TMJ cavity precisely. The spiral CT helped observation and puncture. However, the above methods did not work in collecting synovia. The method of micropump withdrew synovia successfully.</p><p><b>CONCLUSION</b>The improved method and spiral CT are efficient methods to precisely puncture TMJ cavity. The technique of micropump successfully resolves the problem of withdrawing synovia.</p>

Effect of distraction osteogenesis on circadian rhythm of proliferation index of mandibular osteoblast in goat / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The study was to investigate the circadian rhythm of the proliferation index (PI) of the mandibular osteoblast after distraction osteogenesis (DO) by a comparative study to explain the different rhythm characteristics.</p><p><b>METHODS</b>Forty-eight healthy goats were employed and divided randomly into DO group and control. Four weeks after the right side mandible of DO group was distracted, animals of the both groups were killed at 0:00, 4:00, 8:00, 12:00, 16:00, 20:00 time point subsequently. Samples of 2 cm x 2 cm x 0.5 cm bone tissue were excised from distracted zone of DO group and the right mental foramen zone of the control. Primary cell culture method was employed to isolate the osteoblast from bone tissue and a flow cytometric analysis was used to detect the PI of osteoblast. The data was analyzed with cosinor rhythmometry method and the different rhythm between the two groups were investigated.</p><p><b>RESULTS</b>The PI in the two groups demonstrated cosinor waves. The mesor and amplitude in DO group were significant higher compared with the control(P < 0.05), but there was no significant difference for the acrophase between the two groups (P > 0.05).</p><p><b>CONCLUSION</b>The PI of osteoblast after DO showed significant circadian rhythm. It is suggested that DO is helpful to promote osteoblast proliferation and bone regeneration.</p>