Relationship between bone mineral density and bone stiffness in bone fracture

Objectives Using cancellous bone blocks of racehorses, the relationship between bone mineral density (BMD), which indicates bone strength, and stiffness in bone fracture occurrences was studied.Methods Two groups of cancellous bone blocks were prepared: a fractured group, using the first phalangeal bones of seven racehorses with sagittal fractures; and a nonfractured group, using the first phalangeal bones of nine autopsied racehorses without any fractures. By a peripheral quantitative computed tomography scan, the BMD values were shown as color images and evaluated. In addition, the BMD values obtained from the fractured and nonfractured groups were compared with the stiffness values obtained from a compression test.Results The difference between the average BMD values of the fractured and nonfractured groups was easily observed on the BMD color-conversion display image. The average BMD of the fractured group (472.1 mg/cm³) was significantly higher than that of the nonfractured group (284.5 mg/cm³, P = 0.005). Moreover, the average stiffness of the fractured group (5564.5 N/cm) was significantly higher than that of the nonfractured group (3808.6 N/cm, P = 0.008).Conclusion These results suggest that the occurrence of a fracture does not depend on the BMD or the bone stiffness value.     

Effect of bone loss simulation and periodontal splinting on bone strain: Periodontal splints and bone strain

Objectives

The influence of bone loss and periodontal splinting on strains in supporting bone is still not well understood. The aim of this study was to analyse the effect of bone loss and periodontal splints on strains in an anterior mandible structure.

Methods

Ten anterior mandible models were fabricated using polystyrene resin. Eighty human teeth were divided in 10 groups (right first premolar to left premolar) and embedded in simulated periodontal ligament. Strain gauges were attached to the buccal and lingual mandible surfaces. The models were sequentially tested for 7 conditions: no bone alterations and no splinting; 5 mm of bone loss between canine teeth; bone loss associated with resin splint between canine teeth; bone loss with wire splint; bone loss with wire/resin splint; bone loss with extracoronal fibre–glass/resin splint; and bone loss with intracoronal fibre–glass/resin splint. Oblique loads (50, 100, and 150 N) were applied on the teeth. Data were analysed using 3-way ANOVA and Scheffe's test (α = .05).

Results

Strains on buccal surface were higher than on lingual surface. Bone loss resulted in strain increase at 100 and 150 N loading. Dental splinting with resin resulted in strain values similar to the control levels.

Conclusions

Bone loss increased strain mainly in the buccal region. Dental splints with adhesive system and composite resin produced lower bone strains irrespective of occlusal load.     

A comparison of autogenous bone graft combined with deproteinized bovine bone and autogenous bone graft alone for treatment of alveolar cleft

This study assessed the use of composite autogenous bone and deproteinized bovine bone (DBB) for repairing alveolar cleft compared with autogenous bone alone in terms of clinical outcomes and patient morbidity. 30 patients with a mean age of 10.2 ± 1.7 years were randomly divided into two groups. Group I used autogenous cancellous bone graft harvested from the anterior iliac crests by the conventional trapdoor approach. Group II used a composite of DBB and autogenous cancellous bone harvested by a trephine bone collector; the proportion of 1:1 by volume was used. The bone graft quantities of both groups decreased with time. Their average changes were not statistically different over 24 months after grafting. The canines of both groups could spontaneously or orthodontically erupt through the grafting areas. Patients in group II recovered from uncomfortable walking significantly faster than those in group I (p < 0.05) and their duration of hospital stay was significantly shorter than those in group I (p < 0.05). The average operation time, intra-operative blood loss and postoperative pain were less in group II than in group I (p > 0.05).     

Bio-Oss骨粉联合富血小板纤维蛋白在牙槽骨缺损种植引导骨再生后的骨量变化

目的：探讨Bio-Oss骨粉联合富血小板纤维蛋白在牙槽骨缺损种植引导骨再生后骨量的变化。方法：选择106例单颗前牙缺失伴唇侧骨缺损患者,进行种植体种植同期引导骨再生。按随机数字表法随机分为2组,实验组（53例）采用Bio-Oss骨粉联合富血小板纤维蛋白+生物膜引导骨再生,对照组（53例）采用Bio-Oss骨粉联合生物膜引导骨再生。评价2组种植成功率、术后并发症率、种植体唇侧骨壁厚度、骨缺损再生情况。采用SPSS 25.0软件包对数据进行统计学分析。结果：2组种植体种植成功率差异无统计学意义（96.23%:88.68%,P>0.05）。种植后12个月,实验组种植体唇侧骨壁厚度显著大于对照组[（2.72±0.43） mm:（2.51±0.36） mm,P<0.05],不同位点种植体唇侧骨壁厚度大于对照组（P<0.05）,出血指数[（0.32±0.02）:（0.42±0.03）]、探诊深度[（3.31±0.69） mm:（4.32±0.95） mm]、附着丧失[（3.06±0.52） mm:（5.24±1.35） mm]均显著小于对照组（P<0.05）,植骨高度[（2.61±0.52） mm:（2.31±0.35） mm]、成骨高度[（2.59±0.32） mm:（2.01±0.16） mm] 显著大于对照组（P<0.05）。2组患者并发症发生率相比差异无统计学意义（1.89%:5.66%, P>0.05）。结论：Bio-Oss骨粉联合富血小板纤维蛋白可减少骨缺损种植引导骨再生后骨量丢失,促进骨缺损再生。     

Proportion of deproteinized bovine bone and autogenous bone affects bone formation in the treatment of calvarial defects in rabbits

This study assessed new bone formation generated using three different proportions of autogenous bone (AB) and deproteinized bovine bone (DBB). Thirty bicortical skull defects were prepared in 15 rabbits, divided into 3 groups: Group 1, critical size defect (CSD) versus AB as controls; Group 2, DBB versus a composite of AB and DBB using a proportion of 1:1; and Group 3, a composite of AB and DBB using a proportion of 1:2 versus a proportion of 1:4. After 8 weeks, radiographic evaluation was assessed using densitometry and new bone formation by histomorphometry. The mean optical density of the CSD (0.108 ± 0.238) and AB (0.352 ± 0.161) groups differed significantly from the DBB group (1.044 ± 0.093) and the groups using a proportion of 1:1 (0.905 ± 0.078), 1:2 (0.865 ± 0.294) and 1:4 (0.867 ± 0.304). Histomorphometry revealed a higher percentage of new bone in the AB group (30.223 ± 16.722) than in the groups using proportions of 1:2 (22.639 ± 5.659), 1:1 (20.929 ± 6.169), 1:4 (9.621 ± 2.400), DBB (14.441 ± 2.742) and CSD (10.645 ± 8.868), respectively. The 1:2 group had significantly higher bone content than the 1:4 group. The proportions of 1:1 and 1:2 resulted in greater bone formation than the proportion of 1:4, DBB and CSD.     

Composite autogenous bone and demineralized bone matrices used to repair defects in the parietal bone of rabbits

We compared the amount of new bone produced by endochondral and intramembranous autogenous bone grafts in the presence of demineralized bone matrices (DBMs) prepared from intramembranous bone (DBM(IM)) or endochondral bone (DBM(EC)). Thirty-five bone defects were created in the parietal bone of 20 New Zealand White rabbits. In the experimental groups, 5 defects were grafted with endochondral bone, 5 with endochondral bone mixed with DBM(IM)) (EC-DBM(IM)), 5 with intramembranous bone mixed with DBM(IM)(IM-DBM(IM)) and 6 with endochondral bone mixed with DBM(EC)(EC-DBM(EC)). In the control groups, 10 defects were left alone (passive control) and 4 were grafted with rabbit skin collagen (active control). They were all killed on day 14 and the defects were prepared for histological study. Serial sections were cut across the whole defect. Quantitative analyses were made on 202 sections of the experimental groups by image analysis. A total of 414%, 708%, and 85% more new bone was formed in defects grafted with composite EC-DBM(IM), IM-DBM(IM)and EC-DBM(EC), respectively, than those grafted with endochondral bone alone (P<0.001). No bone was formed in either passive or active controls. In conclusion, demineralized bone matrices, particularly those derived from intramembranous bone, have extremely high osteoinductive properties and greatly improve the integration of autogenous bone grafts in the skull.     

Bone regeneration in sinus lifts: comparing tissue-engineered bone and iliac bone

Lifting of the sinus floor is a standard procedure for bony augmentation that enables dental implantation. Although cultivated skin and mucosal grafts are often used in plastic and maxillofacial surgery, tissue-engineered bone has not achieved the same success. We present the clinical results of dental implants placed after the insertion of periosteum-derived, tissue-engineered bone grafts in sinus lifts. Periosteal cells were isolated from biopsy specimens of periosteum, resuspended and cultured. The cell suspension was soaked in polymer fleeces. The cell–polymer constructs were transplanted by sinus lift 8 weeks after harvesting. The patients (n = 35) had either one or both sides operated on. Seventeen had a one-stage sinus lift with simultaneous implantation (54 implants). In 18 patients the implants were inserted 3 months after augmentation (64 implants). Selected cases were biopsied. A control group (41 patients: one stage = 48 implants, two stage = 135 implants) had augmentation with autologous bone only. They were followed up clinically and radiologically for at least 24 months. Both implants and augmentation were significantly more successful in the control group. Failure of augmentation of the tissue-engineered bone was more common after large areas had been augmented. Eleven implants were lost in the study group and only one in the control group. Lifting the sinus floor with autologous bone is more reliable than with tissue-engineered transplants. Although lamellar bone can be found in periosteum-derived, tissue-engineered transplants, the range of indications must be limited.     

The immediate implant: bone preservation and bone regeneration.

This paper demonstrates that an intact extraction socket is not necessary for the successful integration of a titanium implant fixture. Several case reports are used to describe the immediate placement of fixtures into compromised sockets, some in conjunction with bone grafting and/or guided tissue regeneration techniques to enhance the surgical result. Advantages of immediate implant placement are threefold: (1) treatment time is significantly reduced; (2) ridge contour can be preserved; and (3) it is possible to place the fixture in a more ideal axial position, thus enhancing fabrication, esthetics, and biomechanics of the subsequent restoration.     

Serum bone biomarkers and oral/systemic bone loss in humans

We recently reported that subantimicrobial-dose doxycycline (SDD) significantly reduced serum bone-resorption biomarkers in subgroups of post-menopausal women. We hypothesize that changes in serum bone biomarkers are associated not only with systemic bone mineral density (BMD) changes, but also with alveolar bone changes over time. One hundred twenty-eight eligible post-menopausal women with periodontitis and systemic osteopenia were randomly assigned to receive SDD or placebo tablets twice daily for two years, adjunctive to periodontal maintenance. Sera were analyzed for bone biomarkers. As expected, two-year changes in a serum bone biomarker were significantly associated with systemic BMD loss at the lumbar spine (osteocalcin, bone-turnover biomarker, p = 0.0002) and femoral neck (osteocalcin p = 0.0025). Two-year changes in serum osteocalcin and serum pyridinoline-crosslink fragment of type I collagen (ICTP; bone-resorption biomarker) were also significantly associated with alveolar bone density loss (p < 0.0001) and alveolar bone height loss (p = 0.0008), respectively. Thus, we have shown that serum bone biomarkers are associated with not only systemic BMD loss, but with alveolar bone loss as well. Clinical Trial Registration Information: Protocol registered at ClinicalTrials.gov, NCT00066027.     

Relationship between bone mineral density and 2D and 3D structural parameters of bone trabeculae

Objectives We analyzed the two- (2D) and three-dimensional (3D) structure of trabecular bone using bone mineral density (BMD) values as the standard. Correlations between the 2D and 3D structural parameters and BMD in the same samples of trabecular bone were determined to assess the reliability of 2D radiological morphometric analysis of bone as a method for evaluating BMD. Methods The first phalanxes of racehorses were used. A region of interest (ROI) was specified on computed radiography images of the phalanx. The 2D structural parameters for the ROI were determined by morphometric analysis. Then, a block of trabecular bone corresponding to the ROI was excised from the phalanx, and the 3D structural parameters of this bone sample were determined using microfocus X-ray computed tomography. The BMD of each bone sample was measured using peripheral quantitative computed tomography. Results Most, but not all, of the 3D parameters were correlated with BMD (r = 0.82–0.98), and several 2D parameters (skeletal perimeter, skeletal number, skeletal separation, skeletal spacing, fractal dimension, and skeletal pattern factor) were relatively closely correlated with BMD (r = 0.57–0.65). Conclusions These results suggest that the 2D morphometric analysis of bone is a useful, noninvasive method for assessing bone strength.     

The effcct of eel bone powder on bone mineral density in mouse femoral bone

Improvement in bone mineral density (BMD) in the femur after administration of eel bone powder (EBP) was evaluated in ovariectomized (OVX) mice. Female ICR mice were given ovariectomies or sham operations at 9 weeks of age, then housed for 2 weeks during which they were allowed free access to a normal diet. Subsequently, the mice were divided into 3 groups: sham-operated mice fed a normal diet, OVX mice fed a normal diet, and OVX mice fed a diet containing EBP. After the mice in these 3 groups had been housed for 2 months (during which time they were allowed free access to their respective diets), they were dissected and analyzed. The BMD values in the removed femurs were measured by peripheral quantitative computed tomography (pQCT). Femoral total and femoral cancellous BMD values were higher in the EBP-treated group than in the nontreated group. Total BMD: the value in the EBP-treated group was 573 mg/cm³, and that in the non-treated group was 451 mg/cm³ (p<0.05). Cancellous BMD: the value in the EBP-treated group was 242 mg/cm³, and that in the non-treated group was 143 mg/cm³ (p<0.05). However, cortical BMD values did not significantly differ between the EBP-treated group and the non-treated group. Cortical BMD: The value in the EBP-treated group was 1891 mg/cm³, and that in the non-treated group was 1900 mg/cm³. pQCT was used to measure the cortical and cancellous BMD in the long bones. By use of a color conversion technique to display BMD, regional changes in the long bones can be expressed and easily measured. It has been well documented that EBP is effective for improvement or prevention of BMD reduction associated with OVX.     

Particulated bone grafts--effectiveness of bone cell supply

OBJECTIVE: The objective of this study was to measure the amount of viable bone cells present in different types of bone graft. MATERIAL AND METHODS: Bone chips were harvested from the trabecular or cortical bone of the mandible or the iliac crest and either milled or not. The average size of unmilled bone particles was 5 x 5 x 5 mm and that of milled was 2 x 2 x 2 mm. Drill sludge was obtained using either a ball reamer, a diamond ball or an implant drill (the latter from mandibular bone and of average dimension 1 x 1 x 1 mm). A measure of 0.5 g of each category was cultured in Dulbecco's modified Eagle's medium with additives for four weeks. Cell counts were performed. An analysis of the osteocalcin synthesis, the alkaline phosphatase (ALP) activity, the collagen types and the concentration of bone-specific collagen cross-links in medium supernatants was performed. RESULTS: Cells stained positively for osteocalcin and ALP in all groups. Bone-specific collagen cross-links could be quantified and collagen of types I and V was present with no difference in all groups. Unmilled spongy bone chips revealed greater cell counts than milled (P<0.05). Spongy bone chips revealed greater cell counts than cortical bone chips (P<0.05). Drill sludge obtained by hard alloy ball reamer showed the least amount of viable cells (P<0.05). CONCLUSIONS: Bone milling reduces the quantity of osteoblasts. Bone obtained by the ball reamer supplies a smaller number of cells than bone obtained by other methods. Unmilled spongy bone chips appear to offer the greatest amount of viable osteoblasts.     

Effect of diabetes and metabolic control on de novo bone formation following guided bone regeneration

Objectives: To evaluate histologically and morphometrically the effect of experimental diabetes and metabolic control on de novo bone formation following guided bone regeneration (GBR). Methods: Thirty‐five Wistar rats were allocated in three experimental groups: (a) uncontrolled, streptozotocin‐induced diabetes (D); (b) insulin‐controlled diabetes (CD); (c) healthy (H). A standardised titanium microimplant with sandblasted and acid‐etched surface was placed into the inferior border of the mandible bilaterally. On the test site, the microimplant was covered with a titanium reinforced expanded polytetrafluoroethylene membrane securely fixed in the mandible according to the GBR principle. The contralateral site served as control. Following 90 days of healing, undecalcified sections were prepared and planimetric measurements of the per cent vertical height of newly formed bone and the per cent new bone‐to‐implant contact were performed. Results: In all experimental groups, at the GBR treated sites, significant neo‐osteogenesis was observed. The vertical height of the newly formed bone and per cent bone‐to‐implant contact were not statistically significantly different among the H (51.3±7.2% and 50±6.8%), D (30.5±13.4% and 35±16.8%) and CD (41.6±8.3% and 39.9±6.5%) groups. However, uncontrolled diabetes was related to higher outcome variability and increased rate of infectious complications. In the control sites, marginal bone loss was observed in the D group, whereas, in the H and CD groups, minimal new bone formation was observed. Conclusions: Significant de novo bone formation can be achieved via GBR treatment even in the presence of uncontrolled diabetes, although less predictably compared with the healthy status. Insulin‐mediated metabolic control may reverse these adverse effects. To cite this article: Retzepi M, Lewis MP, Donos N. Effect of diabetes and metabolic control on de novo bone formation following guided bone regeneration.
Clin. Oral Impl. Res. 21 , 2009; 71–79.     

Biphasic calcium phosphate ceramics in small bone defects: potential influence of carrier substances and bone marrow on bone regeneration

Objectives: Synthetic calcium phosphate bone substitutes such as hydroxyapatite (HA), β-tricalcium phosphate (β-TCP) or mixtures are alternatives to autogenous bone grafts. TricOs T^® and Collagraft^® are resorbable bone substitutes consisting of biphasic calcium phosphate and a bioactive matrix. Both products have a similar HA to β-TCP ratio, but differ by their matrix. It was the aim of this study to determine the influence of matrix and autologous bone marrow on bone regeneration in a rabbit femoral condyle model.
Material and methods: A critical-sized bicortical channel with a diameter of 4.5 mm was drilled through the femoral condyles in male New Zealand rabbits. Collagraft^® with bone marrow harvested from the posterior iliac crest or TricOs T^® with and without bone marrow was introduced into the defect. Rabbits were euthanized 8 weeks later. The percentage of newly formed bone was determined by micro-computed tomography.
Results: There was no significant difference between bone ingrowth at 8 weeks. Thus, TricOs T^® without bone marrow showed similar bone ingrowth as Collagraft^® with bone marrow. Furthermore, no increase of bone ingrowth could be achieved by adding bone marrow to TricOs T^® in the present setting.
Conclusion: Both bone substitutes showed similar bone ingrowth in this investigation. Using TricOs T^® without bone marrow could avoid donor site morbidity due to harvesting of bone marrow. Further prospective clinical trials will be needed to investigate this approach.     

纳米羟基磷灰石复合骨髓基质细胞修复兔股骨缺损的实验研究

目的探讨使用纳米羟基磷灰石(Nano-Hydroxyapitite,n-HA)作为骨组织工程支架材料的可行性。方法以成骨条件培养液培养兔骨髓基质细胞(BMSCs)至第3代并以1×106/cm2的密度与n-HA复合培养后回植于骨缺损区(1.0cm×0.8cm×0.5cm)。术后6周、12周处死动物,取缺损区及周围骨质进行肉眼、X线片、免疫组化染色观察及计算机图像分析。结果所有植入物无排除或感染。6周及12周通过肉眼及免疫组化观察实验组修复效果明显优于对照组,新骨面积百分比高于对照组(P<0.05),差异有统计学意义。结论n-HA作为骨组织工程支架材料具有可行性。     

Correlation in the densities of augmented and existing bone in guided bone augmentation

Objectives: Our previous work used a rabbit experimental model to investigate the effectiveness of guided bone augmentation (GBA). Although a density similar to that of existing bone is required for successful bone augmentation, few studies have compared the densities of augmented and existing bone. The purpose of the present study was to investigate the correlation in the densities of existing and augmented bone following GBA in rabbit calvaria. Material and methods: The calvaria of 18 adult male Japanese white rabbits were exposed. A circular groove and nine small holes were drilled into the cortical surface of each left parietal bone. A customized, standardized, hemispherical titanium cap was press‐fitted into each groove. Six animals were sacrificed after each healing period of 1, 3, and 6 months and histomorphometric analyses were conducted. Results: Significant increases were observed in the area of augmented bone between 1 and 6 months (62.7±21.6% vs. 93.4±3.9%). In contrast, no significant differences among healing periods were observed in the density of augmented or existing bone. Regression analysis demonstrated a significant positive correlation between the densities of augmented and existing bone; the strength of this correlation increased with the length of healing (R²=0.97). Conclusions: These results suggest that the area of augmented bone increases significantly with the length of healing, filling the occlusive space after 6 months, and that the density of augmented bone depends on that of the existing bone, such that augmented bone has a density about half that of the existing bone. To cite this article:
Yamada Y, Sato S, Yagi H, Ujiie H, Ezawa S, Ito K. Correlation in the densities of augmented and existing bone in guided bone augmentation. Clin. Oral Impl. Res. 23 , 2012; 837–845
doi: 10.1111/j.1600‐0501.2011.02204.x     

Histomorphometric comparison of maxillary pristine bone and composite bone graft biopsies obtained after sinus augmentation

Introduction: Sinus grafting is a technique oriented to facilitate implant placement in posterior atrophic maxillae. Several modifications of the original technique and a wide variety of materials have been proposed; most of them associated with implant survival rates. However, the quality of the bone obtained after the application of certain grafting materials has not been fully elucidated yet. The aims of this multicenter study were to analyse histomorphometrical samples obtained 6 months after sinus grafting using a composite graft consisting of anorganic bovine bone (ABB)+ autologous bone (AB), and to compare these samples with maxillary pristine bone biopsies. Material and methods: Ninety maxillary sinus augmentations were performed for delayed implant placement (N=90) in 45 consecutive patients (test group). Bone cores were harvested 6 months after grafting for histomorphometric and ultrastructural study. Control pristine bone biopsies were taken from the posterior maxilla of 10 patients (control). Bone radiographic changes were assessed up to 24 months after implant loading. Results: The total mean values after analysis of test cores revealed a proportion of 46.08±16.6% of vital bone, 42.27±15.1% of non‐mineralized connective tissue, and 37.02±25.1% of the remaining ABB particles. Significant bone remodeling activities were noticed in sinus grafting samples when compared with pristine bone. A statistically significant difference was observed in the number of osteoid lines between two groups, with higher values in the test one (15.1±11.48% vs. 2.5±2.2%, P=0.0005). Ultrastructural study showed that vital trabecular bone was in intimal contact with ABB particles. Radiographic analysis revealed that the higher the proportion of remaining ABB, the lower the total vertical resorption of the graft. Conclusion: Sinus grafting constitutes an excellent model for the study of de novo bone formation patterns and graft consolidation, when a combination of different bone substitutes is applied. The combination of ABB+AB yields highly satisfactory outcomes from both a clinical and a histologic perspective. To cite this article:
Galindo‐Moreno P, Moreno‐Riestra I, Ávila G, Fernández‐Barbero JE, Mesa F, Aguilar M, Wang H‐L, O'Valle F. Histomorphometric comparison of maxillary pristine bone and composite bone graft biopsies obtained after sinus augmentation.
Clin. Oral Impl. Res. 21 , 2009; 122–128.     

Effects of magnesium intake deficiency on bone metabolism and bone tissue around osseointegrated implants

Objectives: This study evaluated the effect of magnesium dietary deficiency on bone metabolism and bone tissue around implants with established osseointegration. Materials and methods: For this, 30 rats received an implant in the right tibial metaphysis. After 60 days for healing of the implants, the animals were divided into groups according to the diet received. Control group (CTL) received a standard diet with adequate magnesium content, while test group (Mg) received the same diet except for a 90% reduction of magnesium. The animals were sacrificed after 90 days for evaluation of calcium, magnesium, osteocalcin and parathyroid hormone (PTH) serum levels and the deoxypyridinoline (DPD) level in the urine. The effect of magnesium deficiency on skeletal bone tissue was evaluated by densitometry of the lumbar vertebrae, while the effect of bone tissue around titanium implants was evaluated by radiographic measurement of cortical bone thickness and bone density. The effect on biomechanical characteristics was verified by implant removal torque testing. Results: Magnesium dietary deficiency resulted in a decrease of the magnesium serum level and an increase of PTH and DPD levels (P≤0.05). The Mg group also presented a loss of systemic bone mass, decreased cortical bone thickness and lower values of removal torque of the implants (P≤0.01). Conclusions: The present study concluded that magnesium‐deficient diet had a negative influence on bone metabolism as well as on the bone tissue around the implants. To cite this article:
Belluci MM, Giro G, del Barrio RAL, Pereira RMR, Marcantonio E Jr, Orrico SRP. Effects of magnesium intake deficiency on bone metabolism and bone tissue around osseointegrated implants.

Clin. Oral Impl. Res. 22 , 2011; 716–721
doi: 10.1111/j.1600‐0501.2010.02046.x     

骨形态发生蛋白-2与碱性成纤维细胞生长因子在异位和原位成骨中的作用

目的通过骨髓基质细胞（BMSCs）的体外增殖和分化、异位成骨和原位成骨实验来观察骨形态发生蛋白-2（BMP-2）和碱性成纤维细胞生长因子（bFGF）在成骨过程中的作用。方法分别用含BMP-2、bFGF和BMP-2+bFGF的培养液体外培养Beagle犬的BMSCs,通过甲基噻唑基四唑（MTT）比色法测定细胞增殖水平,通过测定碱性磷酸酶（ALP）活性观察细胞的分化情况。将BMSCs与多孔磷酸钙（CPC）分别在含BMP-2、bFGF和BMP-2+bFGF的培养液中复合培养,制成复合材料,一部分植入裸鼠皮下,观察异位成骨情况,另一部分植入Beagle犬的种植体周围骨缺损区,经过荧光标记观察原位成骨情况。结果含有BMP-2+bFGF的培养液促进BMSCs增殖和分化的能力最强。异位成骨情况：BMP-2+bFGF组的成骨量较其他组明显增加,其新骨形成百分比为48.79%±11.31%,高于单一BMP-2组（30.71%±10.85%）和bFGF组（27.33%±9.67%）以及对照组（10.65%±6.05%）。原位成骨术后12周,BMP-2+bFGF组的矿化沉积率高于其他组,其差异有统计学意义（P<0.01）。结论在促进成骨方面,BMP-2和bFGF共同作用优于单一因子。     

Relation of bone turnover markers to periodontal disease and jaw bone morphology in elderly Japanese subjects

Objective:  The purpose of this study was to evaluate the relation of bone turnover markers such as bone formation and resorption to periodontal disease and jaw bone morphology in elderly Japanese subjects.
Subjects and methods:  We selected 148 subjects for participation in this study. All subjects were aged 77 years. The periodontal examination included the assessment of clinical attachment level (CAL). Biochemical parameters of bone turnover measured included urinary deoxypyridinoline, serum osteocalcin (S-OC), and serum bone-specific alkaline phosphatase. In addition, to evaluate the jawbone, we used the mandibular inferior cortex classification (MIC).
Results:  Serum osteocalcin had significantly higher (males: P  =   0.038, females: P  =   0.041) tendency for MIC Class (ANOVA). Multiple linear regression results showed that the number of remaining teeth and S-OC were negatively associated with the percentage of sites with ≥6 mm CAL ( R ² = 0.322, P  < 0.001). Coefficients and betas were −0.71, −0.46 ( P  <   0.001) and −1.11, −0.28 ( P  =   0.002), respectively.
Conclusion:  In conclusion, this study suggests that there is a significant relation of bone turnover markers to periodontal disease and jaw bone morphology in elderly Japanese subjects.