Hydroxyapatite Pellets Research Articles

Inhibitory effect of bovine milk osteopontin on the initial attachment of Streptococcus mutans

We investigated the effect of bovine milk osteopontin (OPN) on the initial adhesion of Streptococcus mutans to hydroxyapatite. Hydroxyapatite pellets were immersed in 5.4 µM OPN solution at 37°C for 30 min. As a control, Milli-Q water was used. S. mutans were incubated at 37°C for 2 h on the pellets. Crystal violet staining and the quantitation of DNA were evaluated. Violet staining was observed on the hydroxyapatite pellets in the control group, but faint staining was seen in the OPN group. Amount of DNA attached to the hydroxyapatite pellet was significantly lower in the OPN group (P < 0.05). These results suggest that initial adhesion of S. mutans to the hydroxyapatite is inhibited with OPN.

Hydroxyapatite and pore former effects on the microstructure and mechanical strength of porous pellets loaded with Lactobacillus

Porous hydroxyapatite (HAP) pellets were prepared by extrusion/spheronization/sintering and loaded with Lactobacillus (La-5). Micronized (PFm) or coarse size (PFc) microcrystalline cellulose were the pore formers, while HAP grades from Budenheim (Tri-cafos®) and Sigma-Aldrich with different specific surface (Sw) were the substrates. Green pellets were heated to sublime microcrystalline cellulose, followed by sintering to form porous pellets. These were characterized by electron/optical microscopy/image analysis, porosimetry, nitrogen sorption and mechanically. Stronger pellets resulted from the high Sw HAP and PFm, and larger pores from the low Sw HAP and PFc. HAP origin impacted on pellet strength. Two loading methods were applied: (i) immersion of pellets in La-5 suspension and (ii) injection of suspension into pellets under vacuum. The latter gave 3-x higher loading, which was maximum for the Tri-cafos® 250 HAP/PFc pellets with larger pores that allowed entrance of bacteria, but adequate strength to resist disintegration during loading. La-5 viability in 250 HAP/PFc pellets was 1.2 × 108 CFU/g.

Anammox-Mediated Hydroxyapatite Granules: Physicochemical Properties, 3D Hierarchy, and Biofilm Thickness.

Biomineralization inspired the development of simultaneous biological transformations and chemical precipitation for simultaneous nitrogen removal and phosphorus recovery from wastewater, which could compensate for the incapacity of phosphorus management in the new biological route of anaerobic ammonium oxidation (anammox). In this study, we strengthened anammox-mediated biomineralization by long-term feeding of concentrated N, P, and Ca substrates, and a self-assembled matrix of anammox bacteria and hydroxyapatite (HAP) was fabricated in a granular shape, defined as HAP-anammox granules. HAP was identified as the dominant mineral using elemental analysis, X-ray diffraction, and Raman spectroscopy. The intensive precipitation of HAP resulted in a higher inorganic fraction and substantially improved settleability of anammox biomass, which facilitated HAP precipitation by acting as nucleation and metabolically elevated pH. By using X-ray microcomputed tomography, we visually represented the hybrid texture of interwoven HAP pellets and biomass, the core-shell layered architecture of different-sized HAP-anammox granules, and their homogeneously regulated thickness of the outer biofilm (from 118 to 635 μm). This unique architecture endows HAP-anammox granules with outstanding settleability, active biofilm, and tightly bonded biofilm with the carrier, which may explain the excellent performance of these HAP-anammox granules under various challenging operational conditions in previous studies.

Inter-Laboratory Study on Measuring the Surface Charge of Electrically Polarized Hydroxyapatite.

Surface charges on implants improve integration into bone and so require a clear protocol for achieving a surface charge and comparable results from different laboratories. This study sintered hydroxyapatite (HAp) at one laboratory to remove the influence of the microstructure on surface charge and then polarized/depolarized the pellets at two different laboratories (in Tokyo and Riga). Surface charges on HAp pellets induced by electric polarization at 400 °C in a 5 kV/cm DC electric field were measured by the thermally stimulated depolarization current (TSDC) method as 6-9 µC/cm2. The surface charge results were comparable between laboratories and also agreed with previously documented values. Recommendations describe conditions for polarization and depolarization to generate a surface charge and repeatedly achieve a comparable outcome. A visual display of the polarization mechanisms and the contribution to surface charge point to further aspects that need further development.

Reaction of stoichiometric hydroxyapatite with different crystallinity in Mg&lt;sup&gt;2+&lt;/sup&gt; aqueous solution

The reaction of stoichiometric hydroxyapatite (HAp) with different crystallinity in Mg2+ aqueous solution was investigated using X-ray absorption near edge structure (XANES). Crystallinity is one of important factors for the properties of HAp. Therefore, this study aimed to clarify the effect of crystallinity on the behavior of HAp in aqueous solutions. Stoichiometric HAp samples with different crystallinities were prepared using an aqueous solution precipitation method and subsequent calcination. The Mg-K XANES spectra of the HAp pellets after immersing in Mg(NO3)2 aqueous solution were classified into two groups: those of Mg-doped HAp and Mg(OH)2. This difference is caused by the solubility of the HAp pellets in water, owing to their crystallinity. This result provides insights into the reaction mechanism of HAp in the human body and facilitates selection of suitable biomaterials.

Quantitative fluoride imaging of teeth using CaF emission by laser induced breakdown spectroscopy.

In this work, we propose the use of molecular emission of calcium fluoride (CaF) by laser induced breakdown spectroscopy (LIBS) to obtain quantitative fluoride distribution images of teeth. LIBS has proved to be an efficient technique to detect low amounts of fluoride in solids, and human teeth have the advantage being a matrix rich in calcium. We used new calibration material from sintered hydroxyapatite pellets doped with fluoride to determine the optimized LIBS conditions of argon flow at 1 L min-1 and using the green emission bands of CaF in 530 nm, and obtained a calibration curve between 0 and 400 μg g-1, and LOD of 18 μg g-1. This methodology was applied within a rat model of fluoride exposure and showed increasing tooth-fluoride with increased exposure dose. To demonstrate applicability of this method in human teeth, we quantified fluoride distribution in teeth from three children from non-fluorinated and fluorinated water regions. Samples from children living in fluoridated water regions showed higher fluoride concentrations in dentine formed after birth, compared to a child from a non-fluoridated region. Teeth have been used as biomarkers for environmental exposure and this new method opens the opportunity in epidemiology research to study critical windows of early life exposure to fluoride as well.

Preparation, characterization, and in vitro release of microencapsulated essential oil hydroxyapatite pellets filled into multifunctional capsules

Oregano essential oil (EO)–loaded pellets were prepared using calcium phosphate substrates of different specific surface areas (Sw) and as binders EO in water emulsions with low or high EO content, stabilized with polysaccharides (PSC) or a combination of PSC-Eudragit® L100-55 (PSC-PLM) encapsulants. Tri-cafos® 250 with high Sw gave higher EO loading and more spherical pellets with narrow size distribution. These were filled into the following hard-shell capsules: gelatin, hydroxypropyl-methyl cellulose (HPMC) based immediate release (Vcaps® plus), gastro-resistant (DRcaps®) and enteric release (Vcaps® enteric), and pullulan (Plantcaps®). FTIR and Raman spectroscopy showed H-bonding between PSC and EO and between PSC and PLM. Pellet mechanical strength decreased with EO content and pellets made with PSC emulsions were stronger than PSC-PLM pellets proving PSC binder ability. Disintegration and release of EO from capsules filled with immediate release pellets (PSC) or enteric pellets (PSC-PLM) were tested sequentially in pH 1.2 and 6.8. Capsule shell influenced disintegration and release. The release of EO from the PSC pellets within 1 h, at pH 1.2 was from gelatin 82%/85% (for low/high EO emulsions) but from Vcaps® plus and Plantcaps® it was lower, 36%/38% and 45%/70% respectively. DRcaps® and Vcaps® enteric capsules confirmed gastro-resistance. The release of enteric (PCS-PLM) pellets was: from gelatin and Vcaps® plus capsules 21%/23% and 20%/21% respectively, but from Plantcaps® 61%/62%, indicating deactivation of Eudragit® L100-55 functionality in the last case. In all cases, release was complete after 180 min, but release of enteric pellets from Vcaps® plus was slower than from gelatin capsules due to the presence of HPMC.

Microstructure, Corrosion Resistance and Wettability of Hydroxyapatite and Silver-Doped Hydroxyapatite

In recent years, synthesis and characterization of Ag-based materials has become an active area of research due to its application in medical area for having antimicrobial properties useful for prosthetic replacement. Pure HydroxyAPatite (HAP) and 1.5wt% Ag-doped HydroxyAPatite (AgHAP) were prepared by sol-gel process and characterized. Ca(NO3)2.4H2O was used as source of Ca precursor, P2O5 was used as a source of P precursor, and AgNO3 has been used as a source of Ag precursor. Pellets of HAP and AgHAP were made after precipitates were consolidated, dried in oven, grounded and sintered in a muffle furnace. Functional groups were determined using FTIR, and compound formations were investigated using XRD. Microstructural analysis was done using SEM and AFM. Wettability was studied using OCA in distilled water, and corrosion resistance and impedance analyses were carried out using ECA in Ringer solution. It was observed from AFM and XRD that grain size decreased from 7.05 ?m to 1.25 ?m. Improvement in corrosion resistance was observed in AgHAP. Wettability studies showed that AgHAP is more hydrophilic in comparison with pure HAP. A correlation between microstructures and properties of hydroxyapetites are discussed in this paper.

Hydroxyapatite Pellets as Versatile Model Surfaces for Systematic Adhesion Studies on Enamel: A Force Spectroscopy Case Study.

Research into materials for medical application draws inspiration from naturally occurring or synthesized surfaces, just like many other research directions. For medical application of materials, particular attention has to be paid to biocompatibility, osseointegration, and bacterial adhesion behavior. To understand their properties and behavior, experimental studies with natural materials such as teeth are strongly required. The results, however, may be highly case-dependent because natural surfaces have the disadvantage of being subject to wide variations, for instance in their chemical composition, structure, morphology, roughness, and porosity. A synthetic surface which mimics enamel in its performance with respect to bacterial adhesion and biocompatibility would, therefore, facilitate systematic studies much better. In this study, we discuss the possibility of using hydroxyapatite (HAp) pellets to simulate the surfaces of teeth and show the possibility and limitations of using a model surface. We performed single-cell force spectroscopy with single Staphylococcus aureus cells to measure adhesion-related parameters such as adhesion force and rupture length of cell wall proteins binding to HAp and enamel. We also examine the influence of blood plasma and saliva on the adhesion properties of S. aureus. The results of these measurements are matched to water wettability, elemental composition of the samples, and the change in the macromolecules adsorbed over time on the surface. We found that the adhesion properties of S. aureus were similar on HAp and enamel samples under all conditions: Significant decreases in adhesion strength were found equally in the presence of saliva or blood plasma on both surfaces. We therefore conclude that HAp pellets are a good alternative for natural dental material. This is especially true when slight variations in the physicochemical properties of the natural materials may affect the experimental series.

Electrical charging of bioceramics by corona discharge

Hydroxyapatite is applied as a coating on orthopedic and dental implants. It directly bonds with bone tissue, improving the implant integration. In vivo biological studies have shown that charged hydroxyapatite may take half the time to bond with bone tissue, compared to non-charged hydroxyapatite. However, there is a challenge: how to charge the coatings? Conventional thermoelectrical poling is not applicable. In this work, a solution is proposed: the corona triode charging. It is demonstrated the possibility of achieving a large and stable negative charge density on hydroxyapatite pellets. The corona discharge has a promising potential in orthopedics and oral implantology.

해양유래 탄수화물을 이용한 인공뼈 바인더의 개발

Marine organisms such as algae have abundant carbohydrates such as alginate, fucoidan, and so on which have viscous biological properties. Laminaria japonica contains a large amount of alginic acids (alginate: ~20% dry weight and fucoidan : ~5% dry weight). It has been known that alginic acid and fucoidan, laminarin, and mannitol, which are mostly components in L. japonica, have excellent medicinal effects. Herein, in order to increase the binding ability, carbohydrate extracted from L. japonica was selected as a binder in brown algae. An additional component (citric acid) was added for crosslinking of the carbohydrate. It has been known that carboxyl group in citric acid and hydroxyl group in carbohydrates could be coupled, and produced ester group. These crosslinking actions by carbohydrate components extracted from marine organisms are expected to increase the compressive strength of the hydroxyapatite pellet as well as positive effect for bone regeneration.

Shape fidelity and sterility assessment of 3D printed polycaprolactone and hydroxyapatite scaffolds

Polycaprolactone (PCL) and hydroxyapatite (HA) composite are widely used in tissue engineering (TE). They are fit to being processed with three-dimensional (3D) printing technique to create scaffolds with verifiable porosity. The current challenge is to guarantee the reliability and reproducibility of 3D printed scaffolds and to create sterile scaffolds which can be used for in vitro cell cultures. In this context it is important for successful cell culture, to have a protocol in order to evaluate the sterility of the printed scaffolds. We proposed a systematic approach to sterilise 90%PCL-10%HA pellets using a 3D bioprinter before starting the printing process. We evaluated the printability of PCL-HA composite and the shape fidelity of scaffolds printed with and without sterilised pellets varying infill pattern, and the sterility of 3D printed scaffolds following the method established by the United States Pharmacopoeia. Finally, the thermal analyses supported by the Fourier Transform Infrared Spectroscopy were useful to verify the stability of the sterilisation process in the PCL solid state with and without HA. The results show that the use of the 3D printer, according to the proposed protocol, allows to obtain sterile 3D PCL-HA scaffolds suitable for TE applications such as bone or cartilage repair.

Fundamental Study on the Coating Ability of Cyanoacrylate Adhesives to Hydroxyapatite Pellet and Surface of Extracted Teeth

Fundamental Study on the Coating Ability of Cyanoacrylate Adhesives to Hydroxyapatite Pellet and Surface of Extracted Teeth

Influences of biosilica content from Amazonian freshwater sponge on calcium phosphates

In this work, hydroxyapatite (HA) reinforced with biogenic silica from Amazonian freshwater sponge, collected at Negro River, Amazonas, was produced using different percentages of the sponges after a calcination process. These freshwater sponges are composed by silicon dioxide (silica) and an organic matrix. It is known that silicon dioxide, when incorporated to the hydroxyapatite structure, shows a tendency to partially or totally replace the (PO4)3− groups. In the present study, hydroxyapatite (HA) was synthesized by an aqueous solution precipitation method, and freshwater sponges were added after heat treatment. The XRD and FTIR results for the samples with 2 wt% and 4 wt% of silica added to hydroxyapatite presented HA and quartz phases, while the samples containing 8 wt%, 15 wt%, and 25 wt% of added silica presented quartz, cristobalite, and a partial HA partially decomposed into β-TCP, as well as whitlockite. XPS analysis showed bands corresponding to silicon for the samples with 8 wt%, 15 wt%, and 25 wt% of added silicon to HA. The increase in calcium/phosphorous (Ca/P) atomic ratio with increasing silicon content indicated the partial substitution of phosphate by silicate groups. Morphological analyses were also performed and showed the preferential presence of a new phase in grain boundaries, differing from pure HA pellets, which probably occurred due to the addition of silicon from freshwater sponge. The unique nanometric morphology for the sample with 25 wt% of silica in hydroxyapatite matrix, with nanometric porosity on the entire surface of the samples, has never been previously reported.

Development and current use of local antibiotic carriers in spondylodiscitis

The current study situation regarding the duration of systemic antibiotic treatment for spondylodiscitis is inhomogeneous and varies between 4-12weeks. Due to the many undesirable side effects the aim is to achieve complete healing without recurrence or hematogenous scatter within the shortest possible period of time. The present pilot study investigated whether the additional application of alocal antibiotic carrier to the surgically treated intervertebral disc space can contribute to afurther reduction of treatment duration. In the pilot study 20patients with acute spondylodiscitis and indications for surgical intervention were included. Surgical treatment was carried out by dorsal instrumentation, radical debridement of the site of infection, and cage interposition in the affected disc space. The remaining disc space was filled with homologous cancellous bone and antibiotic-loaded calcium sulfate hydroxyapatite pellets. Aclassification into along-term and ashort-term antibiotic group was performed. Both groups initially received a10-day parenteral antibiotic administration. This was followed by oral antibiotics for 2 or 12weeks, depending on the group. During the 12-month follow-up inflammation parameters, the local infection situation as well as the bony fusion and antibiotic tolerance were regularly checked. The average age of the patients was 66.7 ± 11.2years. Intraoperative detection of pathogens was successful in 65%. In 60% the antibiotic carrier was loaded with gentamicin, in 40% with vancomycin. At follow-up, all patients except one in the short-term antibiotic group had inflammation parameters within the normal range after 3months. In the long-term antibiosis group, two patients still showed elevated infection values after 3months, otherwise the values were within the normal range. After 12months acomplete cure of the infection was achieved in all patients. Antibiotic treatment intolerance occurred in 10% of the short-term antibiotic group and in 50% of the long-term group. The results of the present pilot study show that with the additional use of absorbable local antibiotic carriers in the surgical treatment of bacterial spondylodiscitis it is possible to shorten the duration of systemic antibiotic treatment to 3weeks. This can reduce the side effects and incompatibility of treatment and still achieve similar healing results.

Modified toothpaste application using prepared toothpaste delivering technique increases interproximal fluoride toothpaste delivery.

ObjectivesWe devised a “prepared toothpaste delivering technique” (PTD technique), a modified the application of toothpaste method for using fluoride toothpaste more effectively. This study aimed to investigate the change in viscosity and fluoride intake into hydroxyapatite of a toothpaste, and deliverability of fluoride toothpaste to the interproximal site with the PTD technique using an interproximal model.MethodsEight toothpaste samples were prepared at the following concentrations: ×1.00, ×1.25, ×1.50, ×1.75, ×2.00, ×3.00, ×4.00, and ×5.00. Viscosity of the toothpaste was measured by a Type‐B viscometer. Dissolution rate of toothpaste and fluoride uptake into the hydroxy apatite pellet were analyzed by a fluoride selective electrode. Application paste volume and delivery rate was measured using interproximal model and image analysis software during using a finger brush front (FBF), finger brush back (FBB), and toothbrush.ResultsAs the dilution ratio increased, the viscosity of the toothpaste decreased sharply, F uptake decreased, and dissolution rate increased. F uptake was significantly reduced when the toothpaste was diluted more than 1.75 times. Therefore, in order to improve the effectiveness of the fluoride toothpaste, it is important to deliver the toothpaste to interproximal areas and pit clefts at low dilution. It was observed that PTD technique can be effectively implemented by the finger brush.ConclusionsThe use of a FBF surface in the analysis of an acrylic interproximal model could aid in applying pressure while blocking the space of the groove and preventing outflow of the toothpaste. It was considered that the PTD technique would improve the effects of the fluoride toothpaste, especially in the interproximal site.

High-speed microphotography of stone breakage with Holmium:YAG lasers

To better understand physical mechanisms of stone comminution in Holmium:YAG laser lithotripsy, high-speed microphotography was used to study the breakage of dry stones in air and hydrated stones in water. Surgically retrieved urinary calculi and hydroxyapatite pellets were pulsed with a Holmium:YAG laser at 0.2–1 J and recorded at ∼250 000 fps using a high-speed camera (Shimadzu HPV-X2) mounted to a Nikon microscope. In air, direct light–stone interactions were seen to produce photothermal melting, vaporization, and micro-explosions. The most apparent damage to stones was due to the micro-explosions, which erupt the stone surface producing craters and pits. The micro-explosions, however, were observed to progressively diminish with number of laser shots, typically stalling after several shots. Increasing the laser energy or moving the fiber tip to a new position was seen to restore the occurrence of micro-explosions before stalling a second time. In water, the laser produced cavitation bubbles, the collapse of which continued to fragment, pit, and erode the stone after each laser pulse. This study suggests that cavitation bubbles contribute strongly to stone comminution. Cavitation bubbles may have a particularly important role in sustaining micro-explosions after initial laser shots.To better understand physical mechanisms of stone comminution in Holmium:YAG laser lithotripsy, high-speed microphotography was used to study the breakage of dry stones in air and hydrated stones in water. Surgically retrieved urinary calculi and hydroxyapatite pellets were pulsed with a Holmium:YAG laser at 0.2–1 J and recorded at ∼250 000 fps using a high-speed camera (Shimadzu HPV-X2) mounted to a Nikon microscope. In air, direct light–stone interactions were seen to produce photothermal melting, vaporization, and micro-explosions. The most apparent damage to stones was due to the micro-explosions, which erupt the stone surface producing craters and pits. The micro-explosions, however, were observed to progressively diminish with number of laser shots, typically stalling after several shots. Increasing the laser energy or moving the fiber tip to a new position was seen to restore the occurrence of micro-explosions before stalling a second time. In water, the laser produced cavitation bubbles, the colla...

Mechanical properties of natural hydroxyapatite using low cold compaction pressure: Effect of sintering temperature

This study describes the effect of sintering temperature on the microstructural, calcium/phosphorus (Ca/P) ion ratios and mechanical properties of non-separated biowastes processed hydroxyapatite (HAp) prepared through a low cold compaction protocol. The HAp was produced by a sintering temperature of 900 °C. Furthermore, HAp sintered at 900 °C was subjected to sintering temperatures of 1000 and 1100 °C.The structural and morphological evolution of the fabricated biomaterials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with electron dispersive X-ray analysis (EDX) respectively. Uniaxial compaction using a pressure of 500 pa was used to produce rectangular shaped pellets to investigate the influence of sintering temperature on the mechanical properties of the produced pellets. From XRD analysis, it was found that hydroxyapatite derived from the biowastes showed good thermal stability and did not exhibit phase instability with traces of other calcium phosphates. The SEM micrographs showed microporous structure of the biomaterials and an increase in temperature reduced the porosity and enhanced the mechanical properties. It was also noticed that the trend of transformation of the average shape of pores was from strongly flattened to round at higher sintering temperatures. Electron dispersive X-ray analysis (EDX) revealed that the atomic Ca/P ratios of the as-sintered HAp specimens ranged from 1.58 to 1.79 for sintering temperatures of 900–1100 °C. The synthesized hydroxyapatite powder showed inclusion of the fluorapatite phase at sintering temperature of 1000 °C with a reduction in the crystallite size. For both scenarios (sintering temperature and compaction pressure), a consistent trend in mechanical properties (microhardness, fracture toughness and Young's modulus) is noticed at every point of measurement except for compressive strength. The reduction in compressive strength when compaction pressure was applied could be as a result of the stress induced in the HAp powders during compaction which may have made it more susceptible to cracks. The hardness value obtained for the synthesized hydroxyapatite pellets is in the range of that of actual human femoral cortical bone.

Whitening Efficacy of Chewing Gum Containing Sodium Metaphosphate on Coffee Stain: Placebo-controlled, Double-blind In Situ Examination.

This study aimed to evaluate the ability of chewing gum containing sodium metaphosphate (SMP) to remove coffee stains from enamel in situ. This was a double-blind (subjects, evaluators), parallel-group, crossover, randomized clinical trial with 30 healthy adult volunteers. Each participant held an appliance with a hydroxyapatite (HA) pellet on the lower lingual side of his or her mouth for two hours to allow pellicle formation. The appliances were subsequently immersed in coffee solution at 37°C for 48 hours. The color of the HA pellet before and after coffee immersion was measured using a spectrophotometer. The participant set the appliance and chewed two pieces of test gum, which contained 7.5 mg of SMP per piece, or control gum without SMP. Each cycle included five minutes of exposure to chewing gum, after which the appliances were placed in 100% relative humidity at room temperature for a 30-minute incubation. This cycle was repeated five times for each gum type. The color of the HA pellet was measured after each chewing cycle using the spectrophotometer. In addition, ΔE* values, which indicate the change in pellet color after each chewing cycle compared with after coffee immersion, were calculated. Data were analyzed using the paired t-test with Bonferroni adjustment to compare ΔE* values of control and test gum after each chewing cycle. The ΔE* values of test gum were significantly higher than those of control gum after all chewing cycles, excluding the first cycle (p<0.05). This finding indicates that test gum containing SMP was more effective at removing coffee stains from the HA pellet than control gum. We conclude that chewing gum containing SMP can effectively remove coffee stains from HA pellets. Thus, SMP is a promising agent to be further explored in tooth-cleaning studies.

Structure reinforcement of porous hydroxyapatite pellets using sodium carbonate as sintering aid: Microstructure, secondary phases and mechanical properties

Porous HAP pellets suitable for loading therapeutic agents were prepared using microcrystalline cellulose (MCC) as pore former and sodium carbonate as sintering aid (SAID). The effect of sintering temperature on the microstructure, mechanical properties and disintegration of pellets prepared at different SAID content was studied. Pellets were characterized by SEM, image analysis, porosimetry and surface area. Secondary phases were identified by PXRD, ATR-FTIR and Raman spectroscopy. Increasing the sintering temperature decreased the diameter, porosity, surface area and friability of the pellets but increased the pore size, tensile strength and disintegration time. The effect of SAID was dependent on sintering temperature. With 5% SAID, a secondary β-tricalcium phosphate (β-TCP) phase was formed, indicated by FTIR peak at 980 cm−1 and characteristic PXRD reflections, whereas with 10%, a secondary B-type carbonated hydroxyapatite phase (CHA) formed, indicated by FTIR peaks at 878 and 1450 cm−1, a broad Raman peak in the region 1020 to 1050 cm−1 and PXRD reflections. Pellets prepared with SAID showed high strength and also porosity. The biphasic HAP/β-TCP pellets exhibited remarkably great strength (4.39 MPa) at the high sintering temperature, while still retaining 43.9% porosity. Relationships were established between the mechanical properties or disintegration time of the porous pellets and the microstructural parameters.