Dicalcium Phosphate Dihydrate Research Articles

Impact of the Applied Electrode System on Properties of Electrodeposited Calcium Phosphate Coatings

The morphology and physicochemical properties of electrochemically deposited CaP coatings depend on the applied process parameters; however, the influence of different electrode systems has not been studied so far. In this work, the possibility of electrochemical deposition of CaP coatings on Ti6Al7Nb alloy using different electrode systems (two-electrode and three-electrode) and the influence of the electrode system and selected ranges of deposition parameters on the properties of the deposited CaP coatings were investigated. The morphology and physicochemical properties of the CaP coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, X-ray diffraction (XRD), and corrosion studies. The results confirmed the effective electrodeposition of CaP coatings using both electrode systems. The applied electrode system and deposition parameters cause changes in the morphology of the obtained coatings. Chemical structure analysis confirmed the presence of mainly hydroxyapatite in the deposited CaP coatings. With the change in voltage/potential in a more cathodic direction, in addition to hydroxyapatite, a dicalcium phosphate dihydrate (DCPD) structure appears. The corrosion tests have shown that the applied deposition parameters have an impact on corrosion resistance and the deposited coatings exhibited protective properties against corrosion under physiological conditions. The CaP coatings with optimal properties for biomedical applications were deposited at a voltage of −4 V in the two-electrode system and a potential of −4 VSCE in the three-electrode system.

A collagen-based laboratory model to mimic sex-specific features of calcific aortic valve disease.

Calcific aortic valve disease (CAVD) shows in the deposition of calcium phosphates in the collagen-rich layer of the valve leaflets. This stiffens the leaflets and eventually leads to heart failure. Recent research suggests that CAVD follows sex-specific pathways: at the same severity of the disease, women tend to have fewer and less crystalline calcifications, and the phases of their calcifications are decidedly different than those of men; namely, dicalcium phosphate dihydrate (DCPD) - one of the mineral phases in CAVD - occurs almost exclusively in females. Furthermore, the morphologies of heart valve calcifications might be sex specific, but the sex-dependence of the morphologies has not been systematically investigated. Herein, we first show that male CAVD patients have more compact and less fibrous calcifications than females, establishing sex-dependent morphological features of heart valve calcification. We then build a model that recapitulates the sex differences of the calcifications in CAVD, which is based on a collagen gel that we calcify in simulated body fluid with varying fetuin A concentrations. With increasing fetuin A concentration, the calcifications become less crystalline and more fibrous, and more DCPD deposits in the collagen matrix, resembling the physicochemical characteristics of the calcifications in female valves. Lower fetuin A concentrations give rise to a model that replicates male-specific mineral characteristics. The models could be used to develop sex-specific detection and treatment methods for CAVD. STATEMENT OF SIGNIFICANCE: Although calcific aortic valve disease (CAVD) affects ∼10 million people globally, researchers have only discovered recently that the disease follows sex-specific pathways, and many of its sex-specific features remain unknown. To further our understanding of sex differences in CAVD and to develop better detection and treatment methods, there is an urgent need to establish models for CAVD that account for its sex-specific manifestations. In this study, we first show that CAVD calcifications in men and women take on different morphologies. Second, we present a model that can replicate physicochemical calcification characteristics of male or female valves, including morphology, and that can help to develop sex-specific detection and treatment methods for CAVD.

Synthesis and characterization of nano dicalcium phosphate dihydrate from biogenic sources

Synthesis and characterization of nano dicalcium phosphate dihydrate from biogenic sources

Comparative Evaluation of Mathematical Model and In Vivo Study of Calcium Phosphate Bone Grafts.

One of the key factors of the interaction 'osteoplastic material-organism' is the state of the implant surface. Taking into account the fact that the equilibrium in regeneration conditions is reached only after the reparative histogenesis process is completed, the implant surface is constantly modified. This work is devoted to the numerical description of the dynamic bilateral material-medium interaction under close to physiological conditions, as well as to the assessment of the comparability of the model with in vitro and in vivo experimental results. The semi-empirical model obtained on the basis of chemical kinetics allows us to describe numerically the processes occurring in the in vitro systems and extrapolates well to assess the behavior of dicalcium phosphate dihydrate (DCPD) material under conditions of ectopic (subcutaneous) implantation in Wistar rats. It is shown that an experiment conducted using a perfusion-diffusion bioreactor in a cell culture medium with the addition of fetal bovine serum (FBS) allows for achieving morphologically and chemically identical changes in the surface of the material in comparison with the real organism. This fact opens up wide possibilities for the creation of an analog of a 'laboratory-on-a-chip' and the transition from classical in vivo models to more controlled and mathematically based in vitro systems.

Dentin remineralization induced by experimental composites containing calcium orthophosphate particles.

This study aimed to verify if composites containing dicalcium phosphate dihydrate particles (DCPD) are able to induce dentin remineralization in vitro. Additionally, the mechanical properties of the materials were tested. Four composites with 50 vol% inorganic content and 1 BisGMA: 1 TEGDMA (mols) were prepared, with different DCPD:glass ratios (50:0, 40:10, 30:20 and 0:50). Ca2 + release in water was monitored for 8 weeks using inductively coupled plasma optical emission spectrometry (n = 3). Composites were applied to artificial lesions (180 μm in depth) prepared in dentin discs and the specimens were kept in simulated body fluid for 8 weeks (n = 8-10). Dentin elastic modulus (EM) and hardness (H) across the lesion were determined by nanoindentation (5 mN, 5 s). Mineral density was determined by microCT. Composite degree of conversion (DC) was determined by near-FTIR spectroscopy (n = 3). Fracture strength and elastic modulus were determined using biaxial flexural test (n = 10). Data were analysed by ANOVA/Tukey test, except for mineral density (Kruskal-Wallis, alpha:0.05). Ca2+ release increase linearly with DCPD fraction in the composite (p < 0.001). Lesions kept in contact with composites containing 40 % and 50 % DCPD presented significant increases in EM and H in the outer region (0-90 μm) and in EM in the inner region (90-180 μm) compared to the negative control. MicroCT was not able to differentiate among treatments. DCPD-containing composites presented DC higher than the control (p < 0.01). Flexural strength and modulus were inversely related to DCPD content (p < 0.001). The composite containing 40 vol% DCPD presented the best compromise between mechanical properties and remineralization potential.

Strategically designed bioactive dual-layer coating of octacalcium phosphate and dicalcium phosphate dihydrate for enhancement of the corrosion resistance of pure magnesium for orthopaedic applications

The application of biodegradable implants manufactured from magnesium (Mg) has gained traction in clinical applications despite concerns about their corrosion behaviour hindering widespread acceptance. This study aims to advance the field by focussing on developing calcium phosphate (CaP) coatings on pure Mg, with the overall objective of modulating the corrosion rate of Mg-based orthopaedic implants to facilitate effective bone remodelling. In this work, different configurations of bioactive CaP-based coatings, including dicalcium phosphate dehydrate (DCPD), octacalcium phosphate (OCP), and dual-layer DCPD-OCP coatings, were applied to control the corrosion behaviour of Mg. XRD and SEM results confirmed the formation of hydroxyapatite (HA) after 14 days of immersion in Hank's solution. The adhesion force results demonstrated that the DCPD coating provided a higher adhesion force than the OCP coating, indicating its potential to enhance the interface stability between the implant and tissue. The results from the potentiodynamic polarisation tests demonstrated a five-fold reduction in corrosion rate for DCPD-OCP-coated Mg compared to uncoated Mg. The incorporation of dual-layer CaP coatings leverages the synergistic advantages of each constituent, enhancing coating adhesion via the compact structure of the DCPD base layer and providing a hydrophilic surface (contact angle ≤15°) via the OCP layer. This dual-layer architecture results in superior corrosion resistance for Mg-based orthopaedic implants, thereby potentially addressing a critical bottleneck in their clinical application.

Comparative Evaluation of Ion Release and Uptake of Fluoride Varnish Containing Dicalcium Phosphate Dihydrate and Casein Phosphopeptide-Amorphous Calcium Phosphate – An Experimental Approach.

The effectiveness of fluoride varnish may be restricted due to inadequate bioavailability of phosphate and calcium ions in the oral cavity. Dicalcium phosphate dihydrate and Casein phosphopeptide–amorphous calcium phosphate have exhibited ability to enhance absorption of calcium and fluoride. The present study aims to compare the remineralization potential of fluoride varnishes containing DCPD and CPP-ACP. Materials and Method: The ion release, precipitation and surface microhardness of enamel blocks were compared following topical application of various Floride varnishes. Thirty enamel blocks were divided into 3 groups following randomization that included: NaF varnish (Group A), CPP-ACP NaF varnish (Group B) and DCPD- NaF varnish (Group C). Pre- and post-treatment microhardness was evaluated using Vickers Microhardness Tester. UV-Vis Spectroscopy assessed the fluoride release at 2 hrs, 4 hrs and 6 hrs. The uptake of fluoride, calcium and phosphates were determined using SEM-EDX. The statistical significance was tested with One-way ANOVA variance for normality followed by post-hoc tests (p ≤ 0.05). Results: All the groups showed statistically significant increase in microhardness post-treatment (Group A: p=0.03, Group B, C: p=0.00). The mean increase in VHN was Group B (53.67) &gt; Group C (34.75) &gt; Group A (27.40). No significant difference in the F release was noted over time (p=0.00). The fluoride release over all three time intervals was Group C &gt; Group B &gt; Group C. Fluoride, Calcium and Phosphates showed highly significant differences between groups (p=0.00) with Group C &gt; Group A&gt; Group B. Conclusion: The novel NaF-DCPD Varnish displayed a promising remineralization potential, however it cannot be conclusively considered to be superior to the commercially available NaF-CPP ACP Varnish. Further in-vivo investigations need to be undertaken to determine the efficacy of NaF-DCPD varnish to determine its feasibility in clinical practice.

Delivery of sodium fusidate from alginate-reinforced, carbonated apatite cement: Physicochemical properties, release behavior, antibacterial and cytotoxicity properties

The present work focuses on the development of composite cements based on dicalcium phosphate dihydrate (DCPD), calcium carbonate CaCO3, sodium alginate (AG), and sodium fusidate (FS). The effect of AG, setting accelerator (0.5 M of Na2HPO4), and antibacterial agent (FS) on the features (setting ability, injectability, cohesion, and compressive strength) of DCPD-CaCO3-based cement was investigated. The reference and composite cements are composed of a nanocrystalline carbonated apatite, similar to bone mineral, and an excess of unreacted vaterite (CaCO3). The incorporation of AG increased the composite cement's total porosity compared to the reference cement (CR). The evaluation of the injectability and cohesion properties showed that adding 10 wt % of AG resulted in a total extrusion of the paste with an improvement in the cohesion of the cement paste. The compressive strength of the cements raised from 3.2 for CR up to 7 MPa with the addition of 10 % of AG and Na2HPO4 . The setting time is significantly reduced by introducing Na2HPO4, resulting in appropriate values (≤ 30 min) for clinical use. Moreover, incorporating 3 wt % of FS in the composite cements had no significant effect on their features. The release study of FS-loaded composites showed sustained and controlled release profiles, with daily released amounts at the therapeutic level. The antibacterial activity of the designed FS-loaded composites demonstrated the effectiveness of the specimens in inhibiting the growth of S. Aureus. Furthermore, the in vitro biological tests did not show any toxicity of the tested cements towards hPBMCs, thereby confirming their biocompatibility.

Comparative histomorphological assessment of the osteoinductive capacity of a nanofibrillated cellulose-based composite and autologous blood clot.

The present study aimed to evaluate and compare the effect of nanofibrillated cellulose (NFC)-based composite with dicalcium phosphate dihydrate and an autologous blood clot (ABC) on the formation of new bone tissue in vivo by histological and histomorphometric assessment. A total of 72 rats with created femoral defects (2 mm) were used. The rats were divided into three groups: (1) with filling of the defect with an ABC, (2) NFC-1-with filling of both the cortical plate and intramedullary space in the defect area, and (3) NFC-2-with filling of only the intramedullary space in the defect area. Histological and histomorphometric analysis was performed to assess the healing of the bone defect after 14, 30 and 60 days. Complete closure of the cortical plate defect was detected in the NFC-2 group on Day 30 (p < 0.0001). Moreover, in both NFC groups on the 30th and 60th days, ongoing osteogenesis was observed, characterized by a large volume of newly formed circular pattern bone tissue in the intramedullary space. This study demonstrated that the NFC-based composite, which is located below the level of the cortical plate, tamponing only the intramedullary space (NFC-2), improves bone tissue repair at the site of a bone defect of the cortical plate and has the potential of prolonged osteoinductivity. Not applicable.

Enhancing corrosion resistance of biodegradable magnesium with dicalcium phosphate dihydrate and Chlorella sp. biomass

Magnesium shows promise as a material for temporary fixation, yet its rapid corrosion poses health risks due to metal ion release. To mitigate these concerns, a biofunctionalization approach involving dicalcium phosphate dihydrate (DCPD) compounds and Chlorella sp. biomass was employed via electrodeposition, silanization, and dip-coating. Surface characterization using XRD, FTIR, and SEM confirmed successful deposition and immobilization. Corrosion behavior was assessed through electrochemical, immersion, and atomic absorption tests, revealing improved resistance and reduced Mg2+ ion release. The coatings demonstrated significant enhancement in corrosion resistance, guarding against pitting and cracks. The findings suggest the potential of Mg/DCPD and Mg/DCPD/microalgae coatings in addressing corrosion-related risks in temporary fixation applications, promising improved biocompatibility and longevity for medical implants.

The corrosion resistance, biocompatibility and antibacterial properties of the silver-doped dicalcium phosphate dihydrate coating on the surface of the additively manufactured NiTi alloy

Additive manufacturing (AM) of NiTi alloys has attracted significant attention for its exceptional forming precision and suitability for processing complex medical implant structures. However, challenges such as the excessive release of Ni2+, bioinertness, and insufficient antibacterial ability have emerged as primary factors impeding the application of NiTi alloy in the medical field. To address these issues, the silver-doped dicalcium phosphate dihydrate (Ag-DCPD) coating is electrochemically deposited on the LPBF-NiTi alloy surface for the first time. The study investigates the effects of varying Ag doping content (2 %, 4 %, and 6 %) on morphology, corrosion resistance, biomineralization, and long-term stability of DCPD coating using scanning electron microscopy (SEM), electrochemical analysis, and immersion tests. Results show that the 4Ag-DCPD coating exhibits the most uniform and dense surface morphology, excellent corrosion resistance, and biomineralization. The corrosion current density (Icorr) is two orders of magnitude lower than that of the LPBF-NiTi alloy matrix (from 1.1 × 10−6 to 1.4 × 10−8), and a dense hydroxyapatite (HA) layer forms after immersion testing. In vitro cell experiments indicate that the 4Ag-DCPD coating maintains high cell viability, favorable cell morphology, and excellent biocompatibility. Additionally, the 4Ag-DCPD coating demonstrates effective antibacterial activity against Escherichia coli (79.75 %) and Staphylococcus aureus (69.33 %), which reduces the risk of implantation infection. Overall, the 4Ag-DCPD coated LPBF-NiTi alloy shows promising clinical application potential as a medical implant.

In vivo evaluation of bioactivity of alginate/chitosan based osteoplastic nanocomposites loaded with inorganic nanoparticles

The influence of two nanostructured osteoplastic materials with different compositions: i) alginate (Alg) matrix, loaded with Zn2+ ions and nanostructured hydroxyapatite (HA) - S1/HA-Zn, and ii) chitosan (CS) matrix loaded with brushite nanoparticles (NPs, dicalcium phosphate dihydrate, DCPD) - S2/DCPD on the healing of an experimental femoral diaphysis defect was investigated. The structure of cellular elements and the lacunar tubular system of the regenerated bone tissue were studied by electron microscopy. Osteogenic cells on the surface and inside S1/HA-Zn formed bone tissue. On the 30th day, the latter had a reticulofibrous and later lamellar structure. On the 30th day, the S2/DCPD biomaterial was integrated mainly into connective tissue and, starting from the 90th day, into the bone tissue, which was formed only on its outer surface. Thus, it has been proven that both biomaterials contribute to the healing of bone wounds. The regenerative potential of the new bone tissue formation of S1/HA-Zn prevails over that of S2/DCPD.

Anti-adhesive effect of naturally obtained dicalcium phosphate dihydrate nanoparticles in the rat uterine wound model

Anti-adhesive effect of naturally obtained dicalcium phosphate dihydrate nanoparticles in the rat uterine wound model

Smart gradient coating suitable for bone growth prepared on plasma-electrolytically oxidised Mg and its sequential degradation behaviour

A gradient coating containing collagen and inorganic strontium/calcium phosphate (Sr/CaP) was fabricated on plasma-electrolytically oxidised magnesium via one-step cathodic electrodeposition. First, Sr-doped dicalcium phosphate dihydrate and hydroxyapatite (DCPD and HA) was deposited, followed by a collagen/CaP layer. The morphological evolution, sequential degradation behaviour, and in vitro bio-properties of the coatings were investigated. The incorporation of collagen remarkably refined the morphology of the CaP, and a more aggregated nano-spherical morphology was observed with increasing collagen concentration. Sr could partially replace Ca in the CaP crystals. Collagen combined with CaP formed a relatively stable skeletal frame, which provided sufficient barrier properties and more sites for the re-precipitation of bone tissue, as well as a more promising proliferation and differentiation ability of osteoblasts. A gradient coating that matches the requirements of bone growth at various periods is suggested for implantation.

Ecofriendly solidification of sand using microbially induced calcium phosphate precipitation

This study introduces microbiologically induced calcium phosphate precipitation (MICPP) as a novel and environmentally sustainable method of soil stabilization. Using Limosilactobacillus sp., especially NBRC 14511 and fish bone solution (FBS) extracted from Tuna fish bones, the study was aimed at testing the feasibility of calcium phosphate compounds (CPCs) deposition and sand stabilization. Dynamic changes in pH and calcium ion (Ca2+) concentration during the precipitation experiments affected the precipitation and sequential conversion of dicalcium phosphate dihydrate (DCPD) to hydroxyapatite (HAp), which was confirmed by XRD and SEM analysis. Sand solidification experiments demonstrated improvements in unconfined compressive strength (UCS), especially at higher Urea/Ca2+ ratios. The UCS values obtained were 10.35 MPa at a ratio of 2.0, 3.34 MPa at a ratio of 1.0, and 0.43 MPa at a ratio of 0.5, highlighting the advantages of MICPP over traditional methods. Microstructural analysis further clarified the mineral composition, demonstrating the potential of MICPP in environmentally friendly soil engineering. The study highlights the promise of MICPP for sustainable soil stabilization, offering improved mechanical properties and reducing environmental impact, paving the way for novel geotechnical practices.

Porous Chitosan/Hydroxyapatite Composite Microspheres for Vancomycin Loading and Releasing.

Porous chitosan/hydroxyapatite (Chi-HAp) composite microspheres were prepared in an aqueous solution containing chitosan, calcium nitrate, and ammonium dihydrogen phosphate by using a hydrothermal method at various temperatures. The investigation indicated that temperature significantly impacted the final product's appearance. Hydroxyapatite (HAp) coupled with dicalcium phosphate dihydrate (DCPD) flakes were obviously found at 65 and 70 °C, while the latter gradually disappeared at higher temperatures. Conversely, synthesis at 90 °C led to smaller particle sizes due to the broken chitosan chains. The microspheres synthesized at 75 °C were selected for further analysis, revealing porous structures with specific surface areas of 36.66 m2/g, pores ranging from 3 to 100 nm, and pore volumes of 0.58 cm3/g. Vancomycin (VCM), an antibiotic, was then absorbed on and released from the microspheres derived at 75 °C, with a drug entrapment efficiency of 20% and a release duration exceeding 20 days. The bacteriostatic activity of the VCM/composite microspheres against Staphylococcus aureus increased with the VCM concentration and immersion time, revealing a stable inhibition zone diameter of approximately 4.3 mm from 24 to 96 h, and this indicated the retained stability and efficacy of the VCM during the encapsulating process.

Synthesis, characterization and antimicrobial analysis of metal-doped (Zn2+ and Ag+) brushite powder for bone regeneration

Brushite, or Dicalcium phosphate dihydrate (CaHPO4·2H2O), is a well-known calcium phosphate (CaP) found in mineralized tissues and is utilized in medical treatment, particularly in bone powder for bone repair. Brushites with Zn2+ and Ag + ions concentration were synthesized in an aqueous solution using the conventional precipitation procedure. The synthesized brushites were characterized using techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Powder X-ray diffraction (PXRD), Scanning Electron Microscopy (SEM), and bioassays were carried out to evaluate their antibacterial and antifungal activities. The alterations in PXRD and FTIR peak locations demonstrated that zinc and silver ions were effectively inserted into the brushite crystals. Initial tests revealed that the powders were innocuous, which make them potentially beneficial for mineralized tissue engineering. These brushites exhibited remarkable antimicrobial activities. Zn-doped brushite completely controlled the growth of fungi namely Macrophomina phaseolina and Sclerotium rolfsii at a concentration of 0.0039 mg mL−1 while Ag-doped brushite completely arrested the growth of these fungi at 0.0312 and 0.0039 mg mL−1, respectively. Likewise, both the brushite exhibited remarkable antibacterial activity against Bacillus thuringiensis and moderate activity against Escherichia coli. Brushite compounds coupled with active metal ions, notably Ag+ and Zn2+, demonstrated promise as a distinct class of reactive materials for bone-related applications.

Synthesis of Chitosan and Ferric-Ion (Fe3+)-Doped Brushite Mineral Cancellous Bone Scaffolds.

Biodegradable scaffolds are needed to repair bone defects. To promote the resorption of scaffolds, a large surface area is required to encourage neo-osteogenesis. Herein, we describe the synthesis and freeze-drying methodologies of ferric-ion (Fe3+) doped Dicalcium Phosphate Dihydrate mineral (DCPD), also known as brushite, which has been known to favour the in situ condition for osteogenesis. In this investigation, the role of chitosan during the synthesis of DCPD was explored to enhance the antimicrobial, scaffold pore distribution, and mechanical properties post freeze-drying. During the synthesis of DCPD, the calcium nitrate solution was hydrolysed with a predetermined stoichiometric concentration of ammonium phosphate. During the hydrolysis reaction, 10 (mol)% iron (Fe3+) nitrate (Fe(NO3)3) was incorporated, and the DCPD minerals were precipitated (Fe3+-DCPD). Chitosan stir-mixed with Fe3+-DCPD minerals was freeze-dried to create scaffolds. The structural, microstructural, and mechanical properties of freeze-dried materials were characterized.

Ion release mechanisms in composites containing CaP particles and hydrophilic monomers

ObjectiveTo investigate the effect of hydrophilic/permeable polymer matrices on water sorption/solubility (WS/SL), Ca2+ release, mechanical properties and hydrolytic degradation of composites containing dicalcium phosphate dihydrate (DCPD) particles. MethodsSix composites were tested, all with 10 vol% of glass particles and either 30 vol% or 40 vol% DCPD. Composites containing 1BisGMA:1TEGDMA in mols (at both inorganic levels) were considered controls. Four materials were formulated where 0.25 or 0.5 of the BisGMA/TEGDMA was replaced by pyromellitic dianhydride glycerol dimethacrylate (PMGDM)/ polyethylene glycol dimethacrylate (PEGDMA). Composites were tested for degree of conversion (FTIR spectroscopy), WS/SL (ISO 4049) and Ca2+ release (inductively coupled plasma optical emission spectroscopy). Fracture toughness (FT) and biaxial flexural strength/modulus (BFS/FM) were determined after 24 h and 60 days in water. The contributions of diffusional and relaxational mechanisms to Ca2+ release kinetics were analyzed using the semi-empirical Salim-Peppas model. Data were analysed by ANOVA/Tukey test (alpha: 0.05). ResultsWS/SL was higher for composites containing PMGDM/PEGDMA compared to the controls (p < 0.001). Only at 40% DCPD the 0.5 PMGDM/PEGDMA composite showed statistically higher Ca2+ release than the control. Relaxation diffusion was the main release mechanism. Initial FT was not negatively affected by matrix composition. BFS (both DCPD fractions) and FM (30% DCPD) were lower for composites with hydrophilic/permeable networks (p < 0.01). After 60 days in water, composites with PMGDM/PEGDMA presented significant reductions in FT, while all composites had reductions in BFS/FM. SignificanceIncreasing matrix hydrophilicity/permeability significantly increased Ca2+ release only at a high DCPD fraction.

Electron paramagnetic resonance and luminescence spectroscopy of transition metal ion impurities and X-ray-induced radicals in brushite

Calcium phosphates hold paramount importance as the constituents of hard tissue of living organisms. Among them, brushite (CaHPO4·2H2O), also known as dicalcium phosphate dihydrate (DCPD), is a common precursor in phosphate synthesis and is becoming increasingly appealing as a biomaterial for bone regeneration applications. This study presents a comparative analysis of structural, morphological, thermal, and spectroscopic properties of synthetic brushite prepared by the wet precipitation method with several brushite products available from commercial vendors. Electron paramagnetic resonance (EPR) spectroscopy revealed that Mn2+ and Fe3+ ions are common trace impurities in commercial products. Following exposure to X-rays, EPR signals of several phosphorous-related radicals emerge. The annealing of the irradiated samples gives rise to broad thermally stimulated luminescence (TSL) signals in the 40–120 °C range, which correlates with the annealing kinetics of the radicals. The stability of radiation-induced EPR and TSL signals is limited by the phase transformation temperature from brushite to monetite (CaHPO4). The results of this study provide novel insights into the formation and stability of phosphorous-related radicals and demonstrate how minuscule amounts of impurity ions can strongly influence the spectroscopic properties of brushite.