Tooth decay is prevalent, and secondary caries causes restoration failures, both of which are related to demineralization. There is an urgent need to develop new therapeutic materials with remineralization functions. This article represents the first review on the cutting edge research of poly(amido amine) (PAMAM) in combination with nanoparticles of amorphous calcium phosphate (NACP). PAMAM was excellent nucleation template, and could absorb calcium (Ca) and phosphate (P) ions via its functional groups to activate remineralization. NACP composite and adhesive showed acid-neutralization and Ca and P ion release capabilities. PAMAM+NACP together showed synergistic effects and produced triple benefits: excellent nucleation templates, superior acid-neutralization, and ions release. Therefore, the PAMAM+NACP strategy possessed much greater remineralization capacity than using PAMAM or NACP alone. PAMAM+NACP achieved dentin remineralization even in an acidic solution without any initial Ca and P ions. Besides, the long-term remineralization capability of PAMAM+NACP was established. After prolonged fluid challenge, the immersed PAMAM with the recharged NACP still induced effective dentin mineral regeneration. Furthermore, the hardness of pre-demineralized dentin was increased back to that of healthy dentin, indicating a complete remineralization. Therefore, the novel PAMAM+NACP approach is promising to provide long-term therapeutic effects including tooth remineralization, hardness increase, and caries-inhibition capabilities.
Amines ; pharmacology ; Calcium ; Calcium Phosphates ; chemistry ; pharmacology ; Dentin ; chemistry ; Humans ; Nanocomposites ; chemistry ; Nanoparticles ; Tooth Remineralization ; methods

To evaluate the sealing potential of self-designed root canal filling material made of calcium phosphate cement (alpha-TCP/TTCP, CPC), the apices of root canals of six adult dogs were purposely perforated and enlarged up to the No 40 instrument. Then CPC was used to fill the root canal. Mean while either calcium hydroxide (Ca(OH)2) paste or hydroxyapatite (HA) paste was used as control. The animals were killed at 4, 12, 20 weeks postoperatively. The different materials about ways of apical closure, restoration periapocal tissues and adaptability to the dentinal surface were observed by histomorphology and scanning electron microscopic. This study revealed that CPC had excellent biocompatibility and adaptability to the dentinal wall. Its osteoconduction can promote the formation of calcific barriers and healing of periapical tissue. The apex can be closed completely. Compared with the control pastes it has advantages of ease of manipulation and better sealing capability. The results showed that CPC could be used as a root canal filling material for pupless teeth with open apex and destructive periapical tissue.
Animals ; Calcium Phosphates ; pharmacology ; Dogs ; Root Canal Filling Materials ; pharmacology ; Root Canal Therapy

BACKGROUNDBiphasic calcium phosphate (BCP) ceramics has a potential advantage as an osteoconductive matrix and has an optimal resorption rate for bone formation. Using BCP ceramics as a bone graft during spinal fusion requires osteogenesis within the material and subsequent bridging between adjacent vertebrae to provide long-term support. Bisphosphonates have been reported to prolong the process of bone healing. The influence of bisphosphonate treatment on bone formation within BCP ceramics in spinal fusion remains unknown. The aim of this study was to evaluate the influence of alendronate on BCP osteogenesis in posterolateral spinal fusion.

METHODSPosterolateral spinal fusion with pedicle screw fixation was performed at the lumbar spine in twenty-two pigs. BCP ceramics were applied as a bone graft to obtain bone fusion between adjacent transverse processes. Eleven pigs in the treatment group received oral alendronate 10 mg/d for three months postoperatively. Eleven pigs in the control group did not receive treatment with alendronate. All animals underwent posterolateral spinal fusion with BCP ceramics. The fusion rate was evaluated three months after the operation.

RESULTSThe fusion rates evaluated by X-ray were 27.3% in the treatment group and 20% in the control group. The fusion rates using histological evaluation were 18.2% in the treatment group and 20% in the control group. The mean volumes of fusion mass were (3.64 +/- 0.86) cm(3) in the treatment group and (4.26 +/- 0.63) cm(3) in the control group. No significant differences were found in either trabecular bone volume or residual BCP volume between treatment and control groups using histological evaluation. The new bone formation within BCP ceramics was greater in the area adjacent to transverse process (P < 0.01).

CONCLUSIONOral alendronate with a dose of 10 mg daily do not inhibit bone formation within BCP ceramics or affect the fusion rate in posterolateral spinal fusion from porcine models.

Alendronate ; pharmacology ; Animals ; Calcium Phosphates ; chemistry ; Ceramics ; chemistry ; Female ; Osteogenesis ; drug effects ; Spinal Fusion ; Swine

OBJECTIVETo evaluate the feasibility of growing tissue-engineered cartilage using chondrocytes seeded onto a biodegradable porous bioceramic, the beta-tricalcium phosphate (beta-TCP).

METHODSA porous bioceramic template of beta-TCP was created in the shape of a disc. Chondrocytes isolated from rabbit articular cartilage were seeded on the beta-TCP template and then kept in rotatory cell culture system (RCCS) for 1 week prior to subcutaneous transplantation into athymic mice. The three-dimensional structure was well-maintained 16 weeks after implantation. After 4, 8, 16 weeks, the specimens were harvested and examined macroscopically, histologically and immunohistochemically.

RESULTSGross morphological and histological analysis of the specimens from the chondrocyte-beta-TCP complex demonstrated new cartilage construction. The overall configuration of the experimental specimens closely resembled the structure of beta-TCP template.

CONCLUSIONThese findings suggest that porous bioceramic (beta-TCP) is a good "matrix" for chondrocyte, and can be used for cartilage engineering.

Animals ; Calcium Phosphates ; pharmacology ; Cartilage ; growth & development ; transplantation ; DNA ; analysis ; Female ; Glycosaminoglycans ; analysis ; Immunohistochemistry ; Mice ; Mice, Nude ; Tissue Engineering

OBJECTIVETo evaluate the occluding effects of three new calcium desensitizers on dentinal tubules in vitro.

METHODSTwenty-five dentin specimens of 1.00 mm thick from freshly extracted third molars were divided into five groups randomly. After treatment with 6% citric acid, group A was treated with distilled water, and group B-E were treated with NovaMin, Pro-Argin, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and 75% NaF glycerin for 2 min respectively. Then the teeth were vertically cleaved into two sections. The surfaces and cross sections were observed by the scanning electron microscope (SEM) and energy dispersive X-ray (EDX), which were analyzed by the Image-Pro Plus software.

RESULTSThe percentage of dentin tubules sealed were (81.6 ± 6.1)%, (71.5 ± 6.3)%, (43.2 ± 2.6)%, (39.9 ± 4.1)% for groups B, C, D and E respectively, and the occluding depth were (30.33 ± 2.26), (24.55 ± 2.58), (16.10 ± 4.65) and (8.90 ± 1.51) µm respectively. The differences between these groups were statistically significant (P < 0.01) except for group B and C (P > 0.05). However, there was no significant difference between all the groups for the Ca/P ratios (P = 0.342).

CONCLUSIONSNovaMin may have better immediate occluding effects than other desensitizers and could deposit a dentin-like mineral.

Arginine ; pharmacology ; Calcium ; metabolism ; Calcium Carbonate ; pharmacology ; Caseins ; pharmacology ; Dentin ; drug effects ; metabolism ; ultrastructure ; Dentin Desensitizing Agents ; pharmacology ; Dentin Permeability ; drug effects ; Dentin Sensitivity ; Fluorides ; pharmacology ; Glass ; chemistry ; Humans ; Microscopy, Electron, Scanning ; Phosphates ; pharmacology ; Phosphorus ; metabolism ; Spectrometry, X-Ray Emission

This study was designed to assess the feasibility of calcium phosphate cement/amifostine complex as a new material for filling the bone defect caused by tumor resection. Mixed-molding method was used, the mass ratios of 0%, 0.1%, 0.5%, 1%, 2% of amifostine/calcium phosphate cement complex being adopted. The curing time, mechanical strength, porosity, scanning electron micrograph, osteosarcoma cells' vitality and vascular endothelial cells' vitality relevant to the complex in vitro were observed. Calcium phosphate cement being loaded with 0.1% and 0.5% amifostine did not affect the curing time, strength, pore size and porosity of calcium phosphate bone cement. In addition proliferation and differentiation of osteosarcoma cells and vascular endothelial cells were not affected. These data suggest that phosphate cement containing 0.1% and 0.5% amifostine be of significance in the treatment regimen as bone defect filling materials..
Amifostine ; pharmacology ; Bone Cements ; pharmacology ; Calcium Phosphates ; pharmacology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cells, Cultured ; Chemical Phenomena ; Endothelial Cells ; cytology ; drug effects ; Humans ; Osteosarcoma ; pathology

*Absorbable Implants ; Biocompatible Materials/*pharmacology ; Bone Regeneration/*drug effects ; Bone Regeneration/physiology ; Bone Substitutes/*pharmacology ; Calcium Phosphates/*pharmacology ; Structure-Activity Relationship

OBJECTIVE: To investigate the protective effects of procyanidin on periprosthetic osteolysis caused by tricalcium phosphate (TCP) wear particles in the mouse calvaria and its mechanism. METHODS: Forty-eight male ICR mice were randomly divided into sham group, TCP group, and procyanidin (0.2 mg/kg, 1 mg/kg, 5 mg/kg)-treated group (n=12). A periprosthetic osteolysis model in the mouse calvaria was established by implanting 30 mg of TCP wear particles onto the surface of bilateral parietal bones following removal of the periosteum. On the 2 day post-operation, procyanidin (1 mg/kg, 5 mg/kg) was locally injected to the calvaria under the periosteum every other day. After 2 weeks, all the mice were sacrificed to collect the blood samples and the calvaria. Periprosthetic osteolysis and osteoclastogenesis in the mouse calvaria were observed by tartrate resistant acid phosphatase (TRAP) staining and HE staining. mRNA levels of TRAP, capthesin K, c-Fos and NFATc1 in the periprosthestic bone tissue were examined by real-time fluorescence quantitative PCR. Serum contents of total anti-oxidation capacity (T-AOC) and MDA, and superoxide dismutase (SOD) activity were determined by chemical colorimetry. Protein expressions of autophagic biomarkers such as Beclin-1 and LC-3 in periprosthetic bone tissue of the calvaria were examined by Western blot. RESULTS: Compared with sham group, periprosthetic osteolysis, osteoclastogenesis, mRNA levels of TRAP, capthesin K, c-Fos and NFATc1, and serum MDA content were increased significantly in the TCP group (P＜0.05), whereas serum T-AOC level and SOD activity were decreased. The protein expressions of Beclin-1 and LC-3, and the conversion of LC3-II from LC3-I were both up-regulated markedly in the mouse calvaria of TCP group (P＜0.05). Compared with TCP group, osteolysis, osteoclastogenesis, mRNA levels of TRAP, capthesin K, c-Fos and NFATc1 and serum MDA content were decreased obviously in the procyanidine group (P＜0.05), serum T-AOC level and SOD activity were increased, the expressions of Beclin-1 and LC-3, and the conversion of LC3-II from LC3-I were down-regulated obviously in the mouse calvaria of procyanidin group (P＜0.05). CONCLUSION Procyanidin has a protective effect of periprosthetic osteolysis caused by TCP wear particles in the mouse calvaia, its mechanism may be mediated by inhibition of oxidative stress and autophagy.
Animals ; Autophagy ; Biflavonoids ; pharmacology ; Calcium Phosphates ; adverse effects ; Catechin ; pharmacology ; Male ; Mice ; Mice, Inbred ICR ; Osteolysis ; Oxidative Stress ; Proanthocyanidins ; pharmacology ; Prostheses and Implants ; adverse effects ; Random Allocation ; Skull

OBJECTIVESTo construct new type of bone graft material by combining calcium phosphate cement (CPC) with bone morphogenetic protein (BMP), and then to detect its osteogenic activity.

METHODSThe surface of CPC and CPC/BMP composite were observed by scanning electron microscope (SEM). CPC and CPC/BMP pellets were separately implanted into the thigh muscle pouches of mice. Samples obtained at different times were tested by histological analysis, SEM, organic substance detection, and alkaline phosphatase (ALP) measurement to observe the induced ectopic bone formation.

RESULTSUnder SEM, the CPC and CPC/BMP composite was found to consist primarily of platy crystals, granular crystals and some small rod-like crystals with micropores about 10-50 microm in size. BMP about 1-5 microm in size was seen like micro globules distributing evenly in the micropores. Newly formed cartilage or bone was not found in the CPC group. In the CPC/BMP group, mesenchymal cells were proliferated and abundant cartilage was found in one week. Woven bone appeared at 2 weeks. New bone formation increased with bone marrow at 4 weeks. At 8 weeks, the implanted CPC/BMP became heterogeneous and a lot of collapsed granules were observed. At the end of 16 weeks, mature lamellar bone appeared and the volume of the implanted CPC/BMP became smaller. One week after implantation, the ALP increased evidently in the CPC/BMP groups and reached the highest level at the 4th week, which was about 168 U/L. The content of organic substance in specimens increased from 22% to 39% by the end of the 16th week, showing the continuous calcification and formation of new bone. SEM also showed that the CPC/BMP composite had good potentiality of ectopic bone induction, and the new bone formed accompanied by the slow degradation of the material.

CONCLUSIONThe results of this study suggested that the CPC/BMP composite could be used as material for bone graft substitute.

Animals ; Bone Cements ; Bone Morphogenetic Proteins ; pharmacology ; Bone Substitutes ; chemical synthesis ; pharmacology ; Calcium Phosphates ; Male ; Materials Testing ; Mice ; Mice, Inbred Strains ; Osteogenesis ; drug effects ; Prosthesis Implantation

OBJECTIVETo investigate effects of hydroxyapatite (HA) and porous tricalcium phosphate/hydroxyapatite (TCP/HA)-coating titanium on the adhesion behavior of human gingival fibroblasts (HGFs).

METHODSCoatings of HA and duplex phases TCP/HA on titanium (Ti) were formed by ion beam assisted deposition (IBAD) method. Attachment, spreading, extracellular matrix (ECM) production, and focal adhesion plaque formation of HGFs were investigated on commercially pure (CP) titanium, HA-coated CP titanium and porous TCP/HA-coated CP titanium. After incubation of HGFs on these substrates, the number of attached cell, the area of cell spreading, immunostained ECM including fibronectin (FN) and type I collage, and vinculin (presenting the formation of focal adhesion plaque) were quantified by morphometric analysis using immunofluorescence microscope.

RESULTSTCP/HA and HA coatings exhibited that the attached cell number and cell spreading area were greater than those of CP titanium (P < 0.05), and the formation of focal adhesion plaque was earlier than that of uncoated substrate (P < 0.05). The number of attached cell and the formation of type I collagen on TCP/HA were more than those on Ti and HA. After 24-hour incubation on TCP/HA surface, the number of attached cell was 198.1 +/- 27.7 and the fluorescent intensity of type I collagen was 154.10 +/- 31.56. While under the same condition, the corresponding numbers for the CP titanium were 125.1 +/- 29.9 and 132.63 +/- 35.26. The differences between the two groups were significant (P < 0.05).

CONCLUSIONSIn this study, the porous TCP/HA coating significantly facilitated the adherence of human gingival fibroblasts to Ti surface and could improve the biocompatibility of titanium.

Calcium Phosphates ; pharmacology ; Cell Adhesion ; drug effects ; Cells, Cultured ; Coated Materials, Biocompatible ; chemistry ; Durapatite ; pharmacology ; Fibroblasts ; cytology ; drug effects ; Gingiva ; cytology ; Humans ; Materials Testing ; Titanium ; chemistry