In vivo study of strontium-doped calcium phosphate cement for biological properties / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the biocompatibility and osteogenic effect of new calcium phosphate cement (CPC) in vivo and to provide experimental basis for its further clinical application.@*METHODS@#Thirty New Zealand white rabbits were randomly divided into four groups: CPC group, CPC+Bio-Oss group, Bio-Oss group and blank control group. Bone defect models of 6 mm in diameter and 7 mm in depth were made on the lateral condyle of bilateral hind legs of the rabbits. CPC, Bio-Oss and CPC+Bio-Oss mixture were implanted into the bone defect according to the group, and the mass ratio of CPC and Bio-Oss was 4 ∶ 1. The experimental animals were sacrificed the 4th, 12th and 24th week after operation. The tissue around the bone defect was taken for histological evaluation by H&E staining. Bone ingrowth fraction (BIF) was calculated. The expression of BMP-2 and COL-Ⅰ was detected by immunohis- tochemical staining by calculating the mean optical density (MOD) of the positive area the 4th week after operation, and the bone healing of each group was evaluated at different time points. The measurement data were analyzed by one-way ANOVA and LSD test was used for multiple comparison of the differences between the means by SPSS 19.0. P < 0.05 was considered to be statistically significant.@*RESULTS@#The results of H&E staining showed that the BIF values of CPC group, CPC + Bio-Oss group and Bio-Oss group were significantly higher than those of blank control group at the same time point (P < 0.01). The BIF values of CPC group were lower than those of Bio-Oss group and CPC + Bio-Oss group (P < 0.01). There was no significant difference between CPC + Bio-Oss group and Bio-Oss group. Immunohistochemical staining showed that the MOD values of BMP-2 and COL-Ⅰ in CPC group were higher than those in blank control group, but lower than those in Bio-Oss group and CPC+Bio-Oss group (P < 0.01). There was no significant difference between BMP-2 and COL-Ⅰ in CPC+Bio-Oss group and Bio-Oss group.@*CONCLUSION@#The new calcium phosphate cement has good biocompatibility and can promote early osteogenesis with stable and long-term effect.

Mechanical properties and effect on osteodifferentiation of induced pluripotent stem cells of chitosan/whisker/calcium phosphate cement composite biomaterial / 中国修复重建外科杂志

Objective: To investigate the mechanical properties of the novel compound calcium phosphate cement (CPC) biological material as well as the biological activity and osteogenesis effects of induced pluripotent stem cells (iPS) seeding on scaffold and compare their bone regeneration efficacy in cranial defects in rats. Methods: Ac- cording to the different scaffold materials, the experiment was divided into 4 groups: pure CPC scaffold group (group A), CPC∶10% wt chitosan as 2∶1 ratio mixed scaffold group (group B), CPC∶10% wt chitosan∶whisker as 2∶1∶1 ratio mixed scaffold group (group C), and CPC∶10% wt chitosan∶whisker as 2∶1∶2 ratio mixed scaffold group (group D). Mechanical properties (bending strength, work-of-fracture, hardness, and modulus of elasticity) of each scaffold were detected. The scaffolds were cultured with fifth generation iPS-mesenchymal stem cells (MSCs), and the absorbance ( A) values of each group were detected at 1, 3, 7, and 14 days by cell counting kit 8 (CCK-8) method; the alkaline phosphatase (ALP) activity, Live/Dead fluorescence staining and quantitative detection, ALP, Runx2, collagen typeⅠ, osteocalcin (OC), and bone morphogenetic protein 2 (BMP-2) gene expressions by RT-PCR were detected at 1, 7, and 14 days; and the alizarin red staining were detected at 1, 7, 14, and 21 days. Twenty-four 3-month-old male Sprague Dawley rats were used to establish the 8 mm-long skull bone defect model, and were randomly divided into 4 groups ( n=6); 4 kinds of scaffold materials were implanted respectively. After 8 weeks, HE staining was used to observe the repair of bone defects and to detect the percentage of new bone volume and the density of neovascularization. Results: The bending strength, work-of-fracture, hardness, and modulus of elasticity in groups B, C, and D were significantly higher than those in group A, and in groups C, D than in group B, and in group D than in group C ( P0.05). Live/Dead fluorescence staining showed that the proportion of living cells in groups B, C, and D at 7 and 14 days was significantly higher than that in group A ( P0.05). RT-PCR showed that the relative expressions of genes in groups B, C, and D at 7 and 14 days were significantly higher than those in group A, and in groups C, D than in group B ( P0.05). Alizarin red staining showed that the red calcium deposition on the surface of scaffolds gradually deepened and thickened with the prolongation of culture time; the A values in groups B, C, and D at 14 and 21 days were significantly higher than those in group A ( P0.05). In vivo repair experiments in animals showed that the new bone in each group was mainly filled with the space of scaffold material. Osteoblasts and neovascularization were surrounded by new bone tissue in the matrix, and osteoblasts were arranged on the new bone boundary. The new bone in groups B, C, and D increased significantly when compared with group A, and the new bone in groups C and D was significantly higher than that in group B. The percentage of new bone volume and the density of neovascularization in groups B, C, and D were significantly higher than those in group A, and in groups C and D than in group B ( P0.05). Conclusion: The mechanical properties of the new reinforced composite scaffold made from composite chitosan, whisker, and CPC are obviously better than that of pure CPC scaffold material, which can meet the mechanical properties of cortical bone and cancellous bone. iPS-MSCs is attaching and proliferating on the new reinforced composite scaffold material, and the repair effect of bone tissue is good. It can meet the biological and osteogenic activity requirements of the implant materials in the bone defect repair.

Mechanical Reinforcement Strategy of Calcium Phosphate Cements by Loading Polymers / 中国医疗器械杂志

Calcium phosphate cement (CPC) is well known for the excellent bioactivity and biocompatibility, however, CPC has been used only for the repair of non-load bearing bone defects due to its brittle nature and low flexural strength. Polymer reinforced CPC has been considered as one of the most effective strategies for mechanical reinforcement. This paper summarizes various kinds of polymers loaded CPC:fiber reinforcement, microsphere reinforcement and dual setting cements. It is aimed to analyze the advantages, disadvantages and principles of the polymers reinforced CPC, and so as to lay a foundation for the further research of improving and manufacturing the CPC with ideal mechanical properties.

Long term effect of calcium carbonate bone cement combined with bFGF in repairing pulp chamber perforation / 国际生物医学工程杂志

Objective To investigate the long-term efficacy of calcium phosphate cement combined with bFGF in repairing pulp chamber perforation and to analyze the correlation between the diameter of the perforation and the curative effect.Methods 75 patients with pulp chamber perforation (82 teeth) were enrolled and divided into the observation group and the control group according to the repair material and method.A series of subgroups were also modeled according to the diameter of the perforation,which include the control group A (≤ 1.5 mm),control group B (1.6～3 mm) and control group C (＞3 mm),as well as the observation group A (≤ 1.5 mm),observation group B (1.6～3 rmm) and observation group C (＞3 mm).The observation group was treated with calcium phosphate cement combined with bFGF,and the control group was treated with calcium phosphate cement alone.Results The total effective rate of the observation group was 97.8％,which was significant higher than 80.6％ in the control group (P＜0.05).The cure rate of the observation group A was 100％,which was significant higher than 73.3％ in the observation group B and 41.7％ in the observation group C (all P＜0.05).The total effective rates of the observation group A and B were significantly higher than 91.7％ in the observation group C (all P＜0.05).The cure rate of the control group A was 92.9％,which was significant higher than 60.0％ in the control group B and 25.0％ in the control group C (all P＜0.05).The total effective rates of the control group A (100％) and B (90.0％) were significantly higher than 91.7％ in the control group C (all P＜0.05).Conclusions Calcium phosphate cement combined with bFGF in repairing the pulp chamber perforation was significantly better than calcium phosphate cement alone.The cure rate of perforation repairing is closely related to the perforation size.The perforation with small diameter may achieve a better repairing effect.

Experimental research about the copolymers of DR-PLGA microcapsule and CPC on the treatment of rabbit femoral defect model / 国际外科学杂志

Objective To study the effects about rhizoma drynariae poly (lactic-co-glycolic acid) (DR-PLGA) /Calcium phosphate cement (CPC) composite scaffold on treating rabbit femoral bone defect.Methods Eight Newzealand rabbits were randomly divided into experiment group(n =4) and control group (n =4).The preparation of rabbit femoral bone defect model,separately implanted DR-PLGA/CPC scaffold and PLGA/CPC scaffold.After 4,8 weeks,we took out the materials,observed with X-ray,gross anatomy,histology observation to evaluate the osteogenetic activity,the effect of accelerating the healing of bone defect.Resuits At the 4th week and 8th week after implantation,the effect of promoting fracture healing and osteogenic activity of the experiment group were greater than those in the control group.Conclusions DR-PLGA combined with CPC could induce new bone formation,promote the healing of rabbit femoral defect.

Research progress on biological characteristics of calcium phosphate cement and its application in stomatology / 医学研究生学报

Being a new non-ceramic hydroxyapatite artificial bone substitute with biological activity , calcium phosphate cement is widely applied in clinical therapy due to its biocompatibility , osteoconductivity , degradability and possibility of being drug carriers . In addition, it also has a good performance in root canal filling , apexification, plerosis of pulp floor perforation and alveolar defects . However , it is necessary to resolve the issues , such as selecting appropriate hardening time and how to enhance compressive strength . This article presents a review of the research progress on the biological properties and clinical application of calcium phosphate cement in stomatology .

Periapical tissue reaction to calcium phosphate root canal sealer in porcine model.

Background: Calcium phosphate cements (CPC) are a group of biomaterials possessing wide scope of use in various branches of medical science. These materials have been proposed to be highly biocompatible and osteoconductive. This study is based on a newly developed CPC formulation (Chitra-CPC) and is aimed at the evaluation of its biocompatibility through an Endodontic Usage Test in a porcine study model. Objective: To evaluate the periapical tissue reaction to Chitra-CPC when used as a root canal sealer/filler material in comparison with a resin sealer, AH Plus (Dentsply). Materials and Methods: The procedure was done on porcine animal model following the ISO 7405 criteria. The material was implanted intentionally into the periapical area of 36 teeth through a root canal procedure carried out in six animals which were divided equally among 1-month and 3-month time periods. Results were based on the histological evaluation of the autopsied specimens after the prescribed time periods. Results: Mild to moderate periapical tissue reaction was found in Chitra-CPC samples belonging to the 1-month time period, whereas majority of the 3-month CPC samples showed an absence of inflammation. Samples of AH Plus in 1-month period showed severe to moderate inflammation, whereas 3-month AH Plus samples had a mild to moderate inflammation. Conclusions: Chitra-CPC is a biocompatible material.

Calcium phosphate cement as an alternative for formocresol in primary teeth pulpotomies.

Background: Formocresol remains to be the preferred medicament in pulpotomy, despite the concerns regarding tissue devitalization and systemic toxicity. Several materials were used as alternatives, but none proved significantly advantageous. Of recent, calcium phosphate cement (CPC) has been projected as an ideal pulpotomy material considering its tissue compatibility and dentinogenic properties. This study explores the suitability of a CPC formulation for pulpotomy, in comparison with formocresol. Materials and Methods: This comparative case study included 10 children (8-12 age group) having a pair of non-carious primary canines (both maxillary and mandibular) posted for extraction. Pulpotomy was performed with CPC in the right canines and formocresol in the left and sealed with IRM® (Dentsply). The teeth were extracted at 70 ± 5 days and sectioned and stained for the histopathological evaluation. Parameters such as pulpal inflammation, tissue reaction to material, dentine bridge formation, location of dentine bridge, quality of dentine formation in bridge, and connective tissue in bridge etc. were evaluated. Results: The histological assessment after 70 days showed no statistically significant difference between the two groups in any of the parameters. However, CPC gave more favorable results in pulpal inflammation, with a lower score of 1.6 against 2.6 for formocresol. CPC samples showed better formation of dentine bridge in quantity and quality. The mean scores for CPC for the extent of dentine bridge formation, quality of dentine bridge and connective tissue in the bridge, were 2.0, 1.4, and 1.2 respectively, whereas the corresponding values for formocresol were 0.8, 0.2, and 1.0. Conclusion: CPC is more compatible to pulp tissues than formocresol and it shows good healing potential. CPC is capable of inducing dentine formation without an area of necrosis.

Vertebroplasty Using Calcium Phosphate Cement for Osteoporotic Vertebral Fractures: Study of Outcomes at a Minimum Follow-up of Two Years

STUDY DESIGN: A case-series study. PURPOSE: To assess the long-term clinical and radiographic outcomes after vertebroplasty using calcium phosphate cement (CPC) for treatment of osteoporotic vertebral fractures (OVF). OVERVIEW OF LITERATURE: Vertebroplasty has become common for the treatment of OVF. However, few studies have reported the clinical application of CPC to vertebroplasty. METHODS: We reviewed 86 consecutive patients undergoing 99 vertebroplasties using CPC. Following repositioning and curettage of the pathological soft tissue of the vertebral body (VB), vertebroplasty using CPC was performed in patients with osteoporotic burst fracture and pseudoarthrosis (procedure A). Vertebroplasty was also performed in patients with osteoporotic compression fractures (procedure B). Back pain and lower back pain were evaluated using the visual analogue scale (VAS). The VB deformity index was measured in a lateral radiograph as the ratio of the VB's height to its longitudinal diameter. RESULTS: The mean age at time of surgery was 77 years old. The mean duration of follow-up was forty-four months. All patients reported decreased pain according to the VAS immediately after vertebroplasty, and pain relief was maintained at the last follow-up in all patients without new OVFs. Complete bone union was observed in all cases by six months after surgery. The mean recovery rate of deformity index was 5.9% in procedure A and 0.02% in procedure B at the final follow-up visit. CONCLUSIONS: Vertebroplasty using CPC gave a satisfactory outcome and no delayed complications in elderly patients with osteoporotic vertebral fractures at follow-up times of at least two years.

Related research on a novel macropores calcium phosphate cement as bone tissue engineering scaffold / 国际生物医学工程杂志

ObjectiveTo investigate the cell toxicity of a novel macropores calcium phosphate cement (CPC) scaffold and its influence on cell adhesion,growth and proliferation.MethodsA novel CPC material was synthesized by means of adding mannitol porogens and applying sodium solution as the cement liquid.The cell growth and proliferation in the novel CPC material extraction was observed by CCK8 assay.Scanning electron microscopy was used to observe hole diameter of the material,cell adhesion and growth in the material.The experiment of three point bending was used to test the biomechanic performance of the CPC material.ResultsThe novel CPC material reached hole diameter value of (267.43±118.01)μm,microporosity of (66.15±6.91)％.Maximum load,flexural strength and toughness of the novel CPC material was increased about one time compared to the traditional CPC(P＜0.05).CCK8 assay showed there were no significant difference of the light absorption value of cells in the CPC extraction in the 4th,6th,8th day compare to the control group (P＞0.05).ConclusionThe novel CPC material has the strong biomechanics performance,macropores,high microporosity and excellent biocompatibility,which is promising for ideal bone tissue engineering scaffold.

Development of chitosan/nanosized apatite composites for bone cements.

Background: Calcium phosphate cements (CPC) is a promising materials for bone defect repair. Nanosized apatite or calcium orthophosphate has a better bioactivity than coarser crystals. Chitosan is produced commercially from chitin that is the structural element in the exoskeleton of crustaceans such as crabs and shrimp. The mixing of nanosized apatite and chitosan may provide the consistency cement, improving mechanical properties of the set bone cement. Objective: Develop nanosized apatite powder with chitosan for bone composite cement. Materials and method: Nanosized apatite was synthesized by chemical method at low temperature and used as the single-component for bone cement. The nanosized apatite powder was characterized using X-ray diffraction method, Fourier transform infrared spectroscopy, and transmission electron microscopy. CPCs were developed based on chitosan/nanosized apatite and calcium sulfate hemihydrate. The compressive strength of the set cement was measured after one to four weeks. The phase composition and the morphology of the set cements were investigated. Results: Calcium sulfate hemihydrate was effective in increasing the compressive strength after setting in a simulated body fluid for seven days. The compressive strength of chitosan/nanosized apatite composite was about 18 MPa after soaking. Conclusion: The workability and setting time of this composite were suitable to handling for bone cement. These composite cements had a significant clinical advantage for substitution of the regenerated bone.

Application of Calcium Phosphate Cement in Bone Defect Repair (review) / 中国康复理论与实践

@#In recent years, more and more biological materials are used in bone defect repair. The ideal materials should not only have good biocompatibility, but also have the right space structure, surface morphology and the physical and chemical properties, to adapt the growth of osteoblasts. Calcium phosphate cement was used more widely among biological materials in bone defect repair with its good biocompatibility, degradability, osteoconductivity, injection, plasticity and other advantages. This paper introduced the experimental research and progress of the calcium phosphate cement application in bone defect repair.

Response of Odontoblast to the Bio-Calcium Phosphate Cement

O efeito da BMP-2 sobre as propriedades osteocondutoras do beta-tricálcio fosfato em defeitos de calvária de ratos / The effect of BMP-2 on the osteoconductive properties of beta-tricalcium phosphate in rat calvaria defects

A neoformação óssea em defeitos críticos em calvária de ratos depende fortemente das propriedades osteocondutoras dos enxertos e biomateriais. Ainda é controverso se os biomateriais podem substituir os enxertos de osso autógeno e se a suplementação dos biomateriais com Proteínas Ósseas Morfogenéticas (BMPs) é necessária para melhorar a formação óssea. Examinamos defeitos críticos em calvária de ratos (5 mm de diâmetro) tratados com β-tricálcio fosfato (TCP; Cerasorb ® M), gel de ácido polilático e poliglicólico (PLA/PGA; Fisiograft®) e cimento de fosfato de cálcio (CPC; Norian® CRS®), isoladamente ou na presença de 5μg de BMP-2 após 45 dias. Defeitos tratados com enxerto de osso autógeno particulado e defeitos não tratados serviram como controle. A formação óssea foi avaliada com base na análise de μCT, análise histomorfométrica e análise de fluorescência. Nós relatamos que o TCP apoia a formação óssea de forma mais eficiente do que o enxerto de osso autógeno particulado. A formação óssea na presença de TCP sozinho atingiu um nível máximo de neoformação óssea, enquanto que a suplementação de BMP-2 falhou em melhorar a neoformação óssea. Em contrapartida, não houve diferença significativa na formação óssea quando o PLA / PGA e o CPC foram comparados ao enxerto autógeno. Além disso, a presença de BMP-2 não alterou substancialmente as propriedades osteocondutoras de PLA/PGA ou de CPC. Conclui-se que as propriedades osteocondutoras do TCP são superiores aos dos enxertos autógenos e que o TCP não exige suplementação de BMP-2. Nossos resultados também mostram que a diminuição da capacidade osteocondutora do PLA/PGA e do CPC não podem ser superadas pela suplementação de BMP-2 em defeitos de calvária de ratos

Bone formation in critical-sized calvaria defects is strongly dependent on the osteoconductive properties of grafts. It remains a matter of controversy whether biomaterials can replace autografts and whether the supplementation of biomaterials with Bone Morphogenetic Proteins (BMPs) is necessary to enhance bone formation. We examined rat calvaria critical-sized defects (5mm diameter) treated with β-tricalcium phosphate (TCP; Cerasorb® M), polylactic and polyglycolic acid gel (PLA/PGA; Fisiograft®) and calcium phosphate cement (CPC; Norian® CRS®), either alone or in the presence of 5μg of BMP-2 after 45 days. Autografts and untreated defects served as controls. Bone formation was evaluated based on μCT analysis, histomorphometric analysis and fluorescence analysis. We report that TCP supported bone formation more efficiently than did autografts. Bone formation in the presence of TCP alone reached a maximal level, as BMP-2 supplementation failed to enhance bone formation. By contrast, no significant difference in bone formation was observed when PLA/PGA and CPC were compared to autografts. Moreover, the presence of BMP-2 did not substantially change the osteoconductive properties of PLA/PGA or CPC. We conclude that the osteoconductive properties of TCP are superior to those of autografts and that TCP does not require BMP-2 supplementation. Our findings also show that the decreased osteoconductive properties of PLA/PGA and CPC cannot be overcome by BMP-2 supplementation in rat calvaria defects

Successful Bone Union Following Calcium Phosphate Cement-Assisted Percutaneous Transpedicular Balloon Kyphoplasty of a Large Interbody Cleft on Long-term Hemodialysis Patient

A 68-year-old diabetic man, who had been on dialysis for 3 years, suffered a five week history of severe back pain that was unresponsive to bed rest, analgesics, and bracing. The vertebral cleft formed by an injury gradually increased in size on sequential plain films. Hence, he underwent calcium phosphate cement-assisted percutaneous transpedicular balloon kyphoplasty to treat a painful interbody vacuum cleft. Immediate pain relief and firm bone union were obtained.

Interaction between odontoblast and bio-calcium phosphate cement reinforced with chitosan

PURPOSE: Calcium phosphate cement (CPC) is one of many useful materials for restoring tooth defects, periodontium and maxillofacial area. Chitosan is a biodegradable material that has been shown to promote the growth and differentiation of osteoblasts in culture. This study examined the interaction between odontoblasts and bio-calcium phosphate cement reinforced with chitosan. MATERIALS AND METHODS: 5x10(3) odontoblastic cells were seeded into each well. Various concentrations of bio-calcium phosphate cement reinforced with chitosan (10, 20, 50, 100, 200, 500 microg/ml, 1, 2, 4 mg/ml) were diluted and added to the wells. The well was incubated for 24 h, 48 h and 72 h. After incubation, the number of cells was assessed to determine the cell viability. A cytokinesis-block micronucleus assay and chromosomal aberration test were carried out to estimate the extent of chromosomal abnormalities. Microscopic photographs and RT-PCR were performed to examine the adhesion potential of bio-calcium phosphate cement reinforced with chitosan. RESULTS: Bio-CPC-reinforced chitosan did not show significant cytotoxicity. The number of damaged chromosomes in the cells treated with Bio-CPC-reinforced chitosan was similar to that in the control cells. There was no significant increase in the number of chromosomal aberrations in the Bio-CPC reinforced chitosan exposed cells. Microscopic photographs and RT-PCR confirmed the adhesive potential of bio-CPC reinforced chitosan to odontoblasts. CONCLUSION: Bio-CPC-reinforced chitosan did not affect the odontoblastic cell viability, and had no significant cytotoxic effect. Bio-CPC-reinforced chitosan showed adhesive potential to odontoblasts. These results are expected form the basis of future studies on the effectiveness of dental restorative materials in Bio-CPC reinforced with chitosan.

The Effect of Cefazolin on Mechanical Properties and Antibacterial Reactions of Calcium Phosphate Cement / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to evaluate the change of mechanical properties and the effect of antibacterial reactions in calcium phosphate cement (CPC) mixed with cefazolin. MATERIALS AND METHODS: We made CPC and a sodium alginate solution and we mixed in variable dosages of cefazolin and then we made a standard sized cement mold. With that we performed compression stress tests, drug releasing tests and antibacterial tests. RESULTS: We found the typical appearance of hydroxyapatite (HA) in the cement mixed with cefazolin. The compressive strength of the cement mixed with cefazolin was higher than that of the cement not mixed with cefazolin and the higher strength cement had a smaller pore size and less porosity. The sodium alginate solution showed the maximum compressive strength at 2 & 4 wt%, but this was decreased at 6 wt%. Cefazolin was released in proportion to the concentration for the first 8 days on the drug releasing test and then a similar amount was released until the tenth day. An antibacterial effect was detected at all dosages of cefazolin on the antibacterial test. CONCLUSION: The compressive strength of the cement mixed with cefazolin was higher than that of the cement not mixed with cefazolin. The drug was released from the cement in a proper fashion and the antibacterial effect was preserved.

Projeto, fabricação e avaliação de implantes craniofaciais personalizados: proposta de utilização de materiais combinados / Design, production and evaluation of customized craniofacial implants: an approach on the use of different materials

Um material adequado para a reconstrução óssea craniofacial deve ser simples de implantar, possuir forma adequada, resistência à fratura e à deformação similares ao osso original, ser eventualmente substituído por osso natural, ser largamente disponível e não possuir um custo muito elevado. Baseado no fato de que um material com todas estas características ainda não está disponível atualmente, torna-se importante buscar novos materiais, novas composições e novas conformações. Diferentes biomateriais são utilizados atualmente para cirurgias de reconstrução craniofacial, cada um apresentando suas vantagens e limitações. Entre eles destacam-se o titânio, o polimetilmetacrilato e os cimentos de fosfato de cálcio. O titânio apresenta difícil conformação; o polimetilmetacrilato polimeriza-se por meio de uma reação exotérmica, podendo causar necrose de tecidos adjacentes ao implante; o cimento de fosfato de cálcio, por sua vez apresenta certa fragilidade, característica de alguns materiais cerâmicos. Neste sentido, este estudo examinou diferentes materiais utilizados para reconstrução craniofacial e suas propriedades mecânicas quando submetidos a ensaios de flexão, como o polimetilmetacrilato, o cimento de fosfato de cálcio e o cimento de fosfato de cálcio reforçado com titânio. Foi verificada a melhoria de propriedades mecânicas do cimento de fosfato de cálcio quando reforçado com malha de titânio. Além disso, este estudo apresenta uma técnica para o projeto e fabricação de implantes craniofaciais personalizados utilizando cimento de fosfato de cálcio reforçado com titânio, validada através de quatro casos de indicação cirúrgica de reconstrução craniofacial.

A material suitable for craniofacial reconstruction must be easy to implant, have the appropriate shape, have the strength and deformation similar to the original bone, be eventually substituted for natural bone, be widely available and present affordable costs. As such as material, with all theses characteristics is still not available, it is important to search for new materials, new compositions and new design. Different biomaterials are used nowadays for craniofacial reconstruction surgeries, each one presenting its advantages and limitations. Among these materials are the titanium, the poli(methilmetacrilate) and the calcium phosphate cements. Titanium presents hard conformation; poli(methilmetacrilate)’s polymerization reaction is exothermic, which may cause necrosis of the adjacent tissues; calcium phosphate cement is brittle, an usual characteristic of ceramic materials. In this way, this study evaluated different materials used for craniofacial reconstruction and its mechanical properties when submitted to bending test, such as poli(methilmetacrilate), calcium phosphate cement and calcium phosphate cement reinforced with titanium. It was verified the improvement in the mechanical properties of the calcium phosphate cement when reinforced with titanium mesh. In addition, this study presents a method for design and manufacturing of customized craniofacial implants using calcium phosphate cement reinforced with titanium mesh, validated through four cases of craniofacial reconstruction surgery indication.

Clinical Experience of the Brushite Calcium Phosphate Cement for the Repair and Augmentation of Surgically Induced Cranial Defects Following the Pterional Craniotomy

OBJECTIVE: To prevent temporal depression after the pterional craniotomy, this study was designed to examine the safety and aesthetic efficacy of the brushite calcium phosphate cement (CPC) in the repair and augmentation of bone defects following the pterional craniotomy. METHODS: The brushite CPC was used for the repair of surgically induced cranial defects, with or without augmentation, in 17 cases of pterional approach between March, 2005 and December, 2006. The average follow-up month was 20 with range of 12-36 months. In the first 5 cases, bone defects were repaired with only brushite CPC following the contour of the original bone. In the next 12 cases, bone defects were augmented with the brushite CPC rather than original bone contour. For a stability monitoring of the implanted brushite CPC, post-implantation evaluations including serial X-ray, repeated physical examination for aesthetic efficacy, and three-dimensional computed tomography (3D-CT) were taken 1 year after the implantation. RESULTS: The brushite CPC paste provided precise and easy contouring in restoration of the bony defect site. No adverse effects such as infection or inflammation were noticed during the follow-up periods from all patients. 3D-CT was taken 1 year subsequent to implantation showed good preservation of the brushite CPC restoration material. In the cases of the augmentation group, aesthetic outcomes were superior compared to the simple repair group. CONCLUSION: The results of this clinical study indicate that the brushite CPC is a biocompatible alloplastic material, which is useful for prevention of temporal depression after pterional craniotomy. Additional study is required to determine the long-term stability and effectiveness of the brushite calcium phosphate cement for the replacement of bone.

Calcium phosphate cement as a "barrier-graft" for the treatment of human periodontal intraosseous defects.

Background : Calcium phosphate cements (CPC) are apparently good candidates for periodontal treatment by virtue of their biocompatibility, mouldability and osteoconductivity. However, the clinical efficacy in this regard has not been established. This study is aimed at the evaluation of the efficacy of a formulation of CPC in healing human periodontal intraosseous defects in comparison with hydroxyapatite ceramic granules. Materials and Methods : In this clinical study, 60 patients with periodontal defects were divided into 2 test groups and 1 control group. The defect sites in the test groups were repaired with CPC and hydroxyapatite ceramic granules (HAG). Debridement alone was given in the control group. The progress was assessed at 3, 6, 9 and 12 months observation intervals through soft tissue parameters (probing depth, attachment level and gingival recession). Results: CPC showed significantly better outcome. Probing depth reduction values of CPC, HAG and Control at 6 months were 5.40 ± 1.43, 3.75 ± 1.71 and 2.90 ± 1.48, and those at 12 months were 6.20 ± 1.80, 4.5 ± 1.91 and 2.95 ± 1.73. Clinical attachment gain values of CPC, HAG and Control at 6 months were 5.15 ± 1.50, 3.45 ± 1.96 and 2.25 ± 1.52, and those at 12 months were 5.80 ± 2.02, 3.55 ± 2.06 and 2.30 ± 1.78, In both cases the P value was <0.001 showing high significance. The gingival recession over 12 months, for the CPC group is lesser than that in the HAG group and the value for the control group is marginally higher than both. Soft-tissue measurements were appended by postoperative radiographs and surgical re-entry in selected cases. Conclusions: Calcium phosphate cement is found to be significantly better than hydroxyapatite ceramic granules. The material could be considered as a "barrier-graft".