OBJECTIVE: This study aimed to compare osseointegration and osteogenesis after single-stage maxillary sinus augmentation with the lateral window using particulate deproteinized porcine bone mineral (PDPBM) and collagenated block deproteinized porcine bone mineral (BDPBM).
METHODS: Bi-maxillary premolars of six beagle dogs were extracted. Eight weeks later, an implant was placed into each augmented sinus with PDPBM or BDPBM according to a split-mouth design. Eight weeks later, all specimens were harvested. Each specimen was separated into the region of interest with the implant (ROI-I) and region of interest with sinus augmented area (ROI-S) 5 mm away from ROI-I. ROI-I and ROI-S were evaluated through micro-computed tomography and histomorphometry.
RESULTS: Bone substitute insertion took longer for the PDPBM group than for the BDPBM group (P = 0.002). In ROI-I, three-dimensional bone-to-implant contact (BIC) did not show statistically significant differences between the groups. Two-dimensional BIC also showed comparable values for both groups. In ROI-S, the graft material volume/tissue volume, trabecular bone pattern factor, and structural model index were higher in the BDPBM group than in the PDPBM group (P < 0.05). The proportions of new bone, graft material, and connective tissue were not significantly statistically different between groups. Less new bone was found in the apical area than in the coronal or middle areas in the BCPBM group (P < 0.05).
CONCLUSIONS: BDPBM may save time in inserting bone substitutes and provide comparable osteogenesis and osseointegration to PDPBM.
CONCLUSIONS: When performing sinus augmentation, BDPBM might improve operator\'s convenience with comparable biological results compared to PDPBM.

A Co-Cr-Mo-C biomedical alloy was processed by investment casting, and its surface was modified using pulsed laser melting. The modified surface underwent rapid solidification, and the exhibited microstructure as well as its corrosion properties were investigated. It was found that the laser surface modified (LSM) Co-Cr-Mo-C alloy possesses enhanced corrosion resistance when compared with the same alloy in the as-cast condition. Microstructural determinations indicated that the LSM Co-Cr-Mo-C alloy exhibited a lack significant solute segregation and a predominantly cellular morphology as a result of the development of a cellular solid-liquid front. The cellular morphology was characterized by a fine distribution of nano-scale M23 C6 carbides at the intercellular regions. Moreover, the austenite (γ) to athermal ε-martensite transformation was totally suppressed in the cellular solidified regions. In contrast, the as-cast alloy develops a coarse dendritic microstructure with coarse carbides in the interdendritic regions. Solute segregation is also present, as well as athermal ε-martensite (13 pct). It was found that the corrosion resistance of the LSM alloy in the Ringer solution exhibits improved corrosion potential and a reduced corrosion current density (-281 mV and 0.032 μA/cm2 , respectively),when compared with the same alloy in the investment as-cast condition (-356 mV and 0.150 μA/cm2 ).

The aim of this study was to evaluate the effects of three different chemotherapeutic agents, following air-abrasive debridement, on surface chemical properties and cytocompatibility. Disks contaminated with Streptococcus gordonii biofilm were treated with air-abrasion and immersion in either 0.9% NaCl (Air + NaCl), 0.05% alkaline electrolyzed water (AEW) (Air + AEW), or 3% H2 O2 (Air + H2 O2 ). Noncontaminated and untreated titanium disks served as a control (As-polished). The efficacy of biofilm removal, magnitude of initial cytocompatibility toward human bone marrow mesenchymal stem cells, and surface chemical properties were determined. In all treatment groups, biofilms containing microorganisms were observed to be completely removed. The data showed discrepancies for cell affinities among treatment groups, whereby: (1) the number of cells attached to the Air + AEW treated surfaces was approximately two times greater than that to the Air + NaCl treated surfaces; and (2) cell spreading was significantly enhanced on the Air + AEW treated surfaces compared with the Air + NaCl or Air + H2 O2 treated surfaces. X-ray photoelectron spectroscopy data showed that the mean relative concentrations of nitrogen to titanium on the As-polished, Air + NaCl, Air + AEW, and Air + H2 O2 surfaces were 0.0079, 0.0237, 0.0071, and 0.0210, respectively, which would provide a clear understanding that these discrepancies could be attributed to sufficient removals of organic-nitrogen deposits at the same magnitude as the As-polished following the Air + AEW treatment. This study clarifies that chemical surface treatment with AEW, as an adjunctive to air-abrasive debridement may be beneficial in restoring surface properties for tissue integration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:183-191, 2020.

Microcrystalline cellulose (MCC) is proposed in this study as an additive in polycaprolactone (PCL) matrices to obtain three-dimensional (3D) printed scaffolds with improved mechanical and biological properties. Improving the mechanical behavior and the biological performance of polycaprolactone-based scaffolds allows to increase the potential of these structures for bone tissue engineering. Different groups of samples were evaluated in order to analyze the effect of the additive in the properties of the PCL matrix. The concentrations of MCC in the groups of samples were 0, 2, 5, and 10% (w/w). These combinations were subjected to a thermogravimetric analysis in order to evaluate the influence of the additive in the thermal properties of the composites. 3D printed scaffolds were manufactured with a commercial 3D printer based on fused deposition modelling. The operation conditions have been established in order to obtain scaffolds with a 0/90° pattern with pore sizes between 450 and 500 µm and porosity values between 50 and 60%. The mechanical properties of these structures were measured in the compression and flexural modes. The scaffolds containing 2 and 5% MCC have higher flexural and compression elastic modulus, although those containing 10% do not show this reinforcement effect. On the other hand, the proliferation of sheep bone marrow cells on the proposed scaffolds was evaluated over 8 days. The results show that the proliferation is significantly better (p < 0.05) on the group of samples containing 2% MCC. Therefore, these scaffolds (PCL:MCC 98:2) have suitable properties to be further evaluated for bone tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 521-528, 2019.

Adverse events have been reported with acrylic bone cements. However, current test standards for acrylic materials fail to characterize the potentially harmful monomers released during the curing stage. In clinical applications, materials are implanted into the human body during this phase. Silicone may be a safer alternative to acrylic cements. Silicone is used in medical applications for its biocompatibility and stability characteristics. Previously, no study has been completed which compares silicone to acrylic cements. In this study, both materials were injected into the cell medium during the curing process which more accurately reflects clinical use of material. Initially, cell cultures followed ASTM standard F813-07 which fails to capture the effects of monomer released during curing. Subsequently, a modified cell culture method was employed which evaluated cytotoxicity while the materials cured. The objective of this study was to capture toxicity data during curing phase. Thus, the test method employed measured and excluded the impact of the exothermic reaction temperature of polymethyl methacrylate (PMMA) on cell growth. The concentration of PMMA monomer was measured at 1 and 24 h after injecting PMMA into culture plates in a manner consistent with established cell growth methodologies. Our results indicate current in vitro cytotoxicity assays recommended by ASTM standards are unable to reveal the real cytotoxic effect caused by methyl methacrylate monomers during polymerization. Our modified experiment can more accurately illustrate the true nature of the toxicity of materials and improve assay results. In these tests, silicone based elastomeric polymers showed excellent cytocompatibility. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2693-2699, 2018.

Borate glasses have shown promising potential as bioactive materials. With recent research demonstrating that glass properties may be modulated by appropriate compositional design. This may provide for indication specific material characteristics and controlled release of therapeutic inorganic ions (i.e., strontium); controlling such release is critical in order to harness the therapeutic potential. Within this sub-chronic pilot study, a rabbit long-bone model was utilized to explore the safety and efficacy of a high borate glass (LB102: 70B2 O3 -20SrO-6Na2 O-4La2 O3 ) particulate (90 - 710 μm) for bone regeneration. Six bilateral full-thickness defects (Ø = 3.5 mm; L = 8 mm) were created in three white New Zealand rabbits. Longitudinal non-decalcified sections of each defect site were produced and stained with Goldner\'s Trichrome. Histopathological examination revealed that LB102 demonstrated osteoconductive and osseointegrative properties with greater new bone being formed within and surrounding LB102 particles, when compared to the sham control. The inflammatory cell infiltration was observed to be slightly higher in the control when compared to LB102 defect sites, while no significant difference in fibrosis and neovascularization was determined, indicating that healing was occurring in a normal fashion. These data further suggest the possible utility of high borate glasses with appropriate compositional design for medical applications, such as bone augmentation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1818-1827, 2017.

Magnesium (Mg) has a long history of investigation as a degradable biomaterial. Physicians first began using Mg for biomedical applications in the late 19th century. Experimentation continued with varying levels of success until the mid-20th century when interest in the metal waned. In recent years the field of Mg-based biomaterials has once again become popular, likely due to advancements in technology allowing improved control of corrosion. Although this has led to success in vascular applications, continued difficulties in predicting and controlling the corrosion rate of Mg in an intraosseous environment has impeded the development of Mg-based biomaterials for orthopedic applications. In this review, an initial summary of the basic properties and the physiological role of Mg are followed by a discussion of the physical characteristics of the metal which lend it to use as a degradable biomaterial. A description of the historical and modern applications for Mg in the medical field is followed by a discussion of the methods used to control and assess Mg corrosion, with an emphasis on alloying. The second part of this review concentrates on the methods used to assess the corrosion and biocompatibility of Mg-based orthopedic biomaterials. This review provides a summary of Mg as a biomaterial from a biological perspective.

Hydroxyapatite with different characteristics in terms of morphology and chemistry were prepared via conventional sintering and low temperature biomimetic mineralization methods. The biomineralization route introduced nanocrystalline carbonate-substituted hydroxyapatite (n-CHA) with needle-like crystals ranging 20-30 nm whereas sintered HA (S-HA) comprised of polygonal grains ranging 2-5 μm. The response of fibroblastic cells was investigated using the extract of the samples whereas Wistar rat-derived mesenchymal stem cells (MSCs) were evaluated on top of each sample while maintaining in an osteogenic-free medium. The proliferation, activity, and morphology of adherent MSCs were determined at different culturing periods. The osteogenic differentiation of MSCs was also assayed by determining expression of runx2, osteonectin, osteopontin, and osteocalcin genes using real time-PCR analysis. The fibroblastic cells exhibited better proliferation rate at the presence of n-CHA compared to S-HA. Furthermore, the MSCs attached and spread well on both n-CHA and S-HA with better proliferation rate and alkaline phosphatase activity on n-CHA. Interestingly, the osteogenic differentiation of MSCs on n-CHA was confirmed by the expression of bone specific proteins whereas poor expression of these proteins was detected for the cells on S-HA. The results showed that the role of morphology, crystallinity, and chemistry of hydroxyapatite is crucial for osteogenesis differentiation of MSCs. The results predict osteoinductivity of n-CHA, because MSCs differentiation occurred at the absence of osteogenic medium. However, in vivo data are also required to support this suggestion.