Melvin L. Munar
Kyushu University
Ultimate tensile strengthCeramicBrittlenessFabricationSolubilityArtificial boneComposite materialMaterials scienceMineralogyCancellous bonePhosphateSinteringPolyurethanePLGACarbonate apatiteMechanical strengthBone regenerationHydrothermal treatmentMechanical propertyBone substituteCompressive strengthChemical engineeringCrystallinityCalciumMagnesiumPorosity
30Publications
11H-index
284Citations
Publications 30
Newest
#1Bang Thi Le (HUST: Hanoi University of Science and Technology)
#2S. Ramesh (UM: University of Malaya)
Last. Xingling Shi (Jiangsu University)H-Index: 8
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The effect of 1 wt% magnesium oxide (MgO) as sintering additive on the sintering behaviour, microstructure, mechanical properties and cell activities of 0.4 and 1.6 wt% silicon-substituted hydroxyapatite (MgO-0.4Si-HA and MgO-1.6Si-HA) was investigated. The powders were synthesized by the wet-chemical neutralization method and the compacts were pressureless sintered in air between 1150 and 1250 °C for 2 h. The results showed that MgO-0.4Si-HA promoted the formation of the secondary phase of β-TC...
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#1Koichiro Hayashi (Kyushu University)H-Index: 24
#2Melvin L. Munar (Kyushu University)H-Index: 11
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Abstract The pore architecture of scaffolds is a critical factor for angiogenesis and bone regeneration. Although the effects of scaffold macropore size have been investigated, most scaffolds feature macropores with poor uniformity and interconnectivity, and other parameters (e.g., microporosity, chemical composition, and strut thickness) differ among scaffolds. To clarify the threshold of effective macropore size, we fabricated honeycomb scaffolds (HCSs) with distinct macropore (i.e., channel) ...
9 CitationsSource
#1Koichiro Hayashi (Kyushu University)H-Index: 24
#2Melvin L. Munar (Kyushu University)H-Index: 11
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Abstract Artificial bone substitutes that can solve the problems associated with autogenous bone grafts are essential. In this study, macroporous carbonate apatite (CO3Ap) granules with the same composition as natural bone were implanted into distal epiphysis defects in rabbit femurs. Material resorption and bone regeneration were then evaluated. The macroporous granules were obtained by extruding honeycomb (HC) structure rods containing calcium hydroxide, pulverizing the rods to granules, carbo...
4 CitationsSource
#1Kunio Ishikawa (Kyushu University)H-Index: 53
#2Melvin L. Munar (Kyushu University)H-Index: 11
Last. Youji Miyamoto (University of Tokushima)H-Index: 29
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: Carbonate apatite (CO3 Ap) block can be used as a bone substitute because it can be remodeled to new natural bone in a manner conforming with the bone remodeling process. Among the many porous structures available, honeycomb (HC) structure is advantageous for rapid replacement of CO3 Ap to bone. In this study, the feasibility to fabricate a CO3 Ap HC was studied, along with its initial tissue response in rabbit femur bone defect. First, a mixture of Ca(OH)2 and a wax-based binder was extruded ...
6 CitationsSource
#1Yuki Sugiura (AIST: National Institute of Advanced Industrial Science and Technology)H-Index: 7
#2Melvin L. Munar (Kyushu University)H-Index: 11
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Although octacalcium phosphate (OCP) powder and a collagen/gelatin composite demonstrate good potential as bone substitutes, an OCP block has not been fabricated to date. In this study, the feasibility of fabricating an OCP block was evaluated through a dissolution-precipitation reaction using a calcium sulfate hemihydrate (CSH) block as a precursor. When the block was immersed in a phosphate salt solution, its composition changed to that of OCP, while its structure was maintained. The diametral...
9 CitationsSource
#1Yuki Sugiura (Kyushu University)H-Index: 7
#2Melvin L. Munar (Kyushu University)H-Index: 11
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Abstract Octacalcium phosphate (OCP) foam with an interconnected porous structure was fabricated through phase conversion via a dissolution–precipitation reaction using calcium sulfate hemihydrate (CSH: CaSO 4 ·1/2H 2 O) granules as precursors in a sodium dihydrogen phosphate (NaDP: NaH 2 PO 4 ) solution. The diametral tensile strength and porosity of the OCP foam were 0.15 ± 0.04 MPa and 69.4% ± 0.04%, respectively. When the OCP foam was implanted into bone defects in a rabbit femur, the OCP fo...
9 CitationsSource
#1Tya Indah Arifta (Kyushu University)H-Index: 2
#2Melvin L. Munar (Kyushu University)H-Index: 11
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Abstract Interconnected porous calcium-deficient hydroxyapatite (cdHAp) blocks may be an ideal biomaterial to repair bone defects because of their greater similarity to human bone than that of sintered hydroxyapatite (HAp) with respect to calcium content and crystallinity. In particular, the interconnected pores in cdHAp may provide pathways for cell migration and tissue ingrowth. In this study, the feasibility of fabricating interconnected porous cdHAp blocks through the setting reaction of alp...
17 CitationsSource
#1Tya Indah Arifta (Kyushu University)H-Index: 2
#2Melvin L. Munar (Kyushu University)H-Index: 11
Last. Kunio IshikawaH-Index: 53
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The aim of present study was to fabricate porous a-tricalcium phosphate (a-TCP) with adequate mechanical strength and pore interconnectivity. First step, a-TCP spheres were exposed to acidic calcium phosphate solution to allow growth and interlocking of dicalcium phosphate dihydrate (DCPD) crystals precipitated on the surface of the a-TCP spheres. Then, the DCPD-coated a-TCP spheres were sintered at 1,500°C for 6h, which resulted in the fusion of spheres to form the interconnected porous block. ...
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#1Taro Nikaido (Kyushu University)H-Index: 3
#2Kanji Tsuru (Kyushu University)H-Index: 32
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Abstract Porous β-tricalcium phosphate (β-TCP) has attracted attention as an artificial bone substitute. α-TCP foam that mimics the fully interconnected porous structure of the cancellous bone can be fabricated by a ceramics foam method, which requires sintering at high temperature. However, β-TCP foam could not be fabricated by the ceramics foam method since the sintering temperature required is above the αβ transition temperature. To fabricate the β-TCP foam that mimics the fully interconnecte...
13 CitationsSource
#1Xingling Shi (Jiangsu University)H-Index: 8
#2Lingli Xu (Jiangsu University)H-Index: 7
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Abstract Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant–gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study,...
26 CitationsSource