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1.
Biomed Mater Eng ; 35(4): 365-375, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38578877

RESUMO

BACKGROUND: ß-tricalcium phosphate (ß-TCP) has been successfully utilized as a 3D printed ceramic scaffold in the repair of non-healing bone defects; however, it requires the addition of growth factors to augment its regenerative capacity. Synthetic bone mineral (SBM) is a novel and extrudable carbonate hydroxyapatite with ionic substitutions known to facilitate bone healing. However, its efficacy as a 3D printed scaffold for hard tissue defect repair has not been explored. OBJECTIVE: To evaluate the biocompatibility and cell viability of human osteoprecursor (hOP) cells seeded on 3D printed SBM scaffolds via in vitro analysis. METHODS: SBM and ß-TCP scaffolds were fabricated via 3D printing and sintered at various temperatures. Scaffolds were then subject to qualitative cytotoxicity testing and cell proliferation experiments utilizing (hOP) cells. RESULTS: SBM scaffolds sintered at lower temperatures (600 °C and 700 °C) induced greater levels of acute cellular stress. At higher sintering temperatures (1100 °C), SBM scaffolds showed inferior cellular viability relative to ß-TCP scaffolds sintered to the same temperature (1100 °C). However, qualitative analysis suggested that ß-TCP presented no evidence of morphological change, while SBM 1100 °C showed few instances of acute cellular stress. CONCLUSION: Results demonstrate SBM may be a promising alternative to ß-TCP for potential applications in bone tissue engineering.


Assuntos
Fosfatos de Cálcio , Proliferação de Células , Sobrevivência Celular , Teste de Materiais , Impressão Tridimensional , Alicerces Teciduais , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Alicerces Teciduais/química , Humanos , Sobrevivência Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Engenharia Tecidual/métodos , Células Cultivadas
2.
J Biomed Mater Res B Appl Biomater ; 112(1): e35347, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38247237

RESUMO

Bone tissue has the capacity to regenerate under healthy conditions, but complex cases like critically sized defects hinder natural bone regeneration, necessitating surgery, and use of a grafting material for rehabilitation. The field of bone tissue engineering (BTE) has pioneered ways to address such issues utilizing different biomaterials to create a platform for cell migration and tissue formation, leading to improved bone reconstruction. One such approach involves 3D-printed patient-specific scaffolds designed to aid in regeneration of boney defects. This study aimed to develop and characterize 3D printed scaffolds composed of type I collagen augmented with ß-tricalcium phosphate (COL/ß-TCP). A custom-built direct inkjet write (DIW) printer was used to fabricate ß-TCP, COL, and COL/ß-TCP scaffolds using synthesized colloidal gels. After chemical crosslinking, the scaffolds were lyophilized and subjected to several characterization techniques, including light microscopy, scanning electron microscopy, and x-ray diffraction to evaluate morphological and chemical properties. In vitro evaluation was performed using human osteoprogenitor cells to assess cytotoxicity and proliferative capacity of the different scaffold types. Characterization results confirmed the presence of ß-TCP in the 3D printed COL/ß-TCP scaffolds, which exhibited crystals that were attributed to ß-TCP due to the presence of calcium and phosphorus, detected through energy dispersive x-ray spectroscopy. In vitro studies showed that the COL/ß-TCP scaffolds yielded more favorable results in terms of cell viability and proliferation compared to ß-TCP and COL scaffolds. The novel COL/ß-TCP scaffold constructs hold promise for improving BTE applications and may offer a superior environment for bone regeneration compared with conventional COL and ß-TCP scaffolds.


Assuntos
Fosfatos de Cálcio , Colágeno Tipo I , Bovinos , Animais , Humanos , Fosfatos de Cálcio/farmacologia , Regeneração Óssea , Microscopia Eletrônica de Varredura
3.
Gels ; 9(8)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37623094

RESUMO

Collagen, an abundant extracellular matrix protein, has shown hemostatic, chemotactic, and cell adhesive characteristics, making it an attractive choice for the fabrication of tissue engineering scaffolds. The aim of this study was to synthesize a fibrillar colloidal gel from Type 1 bovine collagen, as well as three dimensionally (3D) print scaffolds with engineered pore architectures. 3D-printed scaffolds were also subjected to post-processing through chemical crosslinking (in N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide) and lyophilization. The scaffolds were physicochemically characterized through Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis, Differential Scanning Calorimetry, and mechanical (tensile) testing. In vitro experiments using Presto Blue and Alkaline Phosphatase assays were conducted to assess cellular viability and the scaffolds' ability to promote cellular proliferation and differentiation. Rheological analysis indicated shear thinning capabilities in the collagen gels. Crosslinked and lyophilized 3D-printed scaffolds were thermally stable at 37 °C and did not show signs of denaturation, although crosslinking resulted in poor mechanical strength. PB and ALP assays showed no signs of cytotoxicity as a result of crosslinking. Fibrillar collagen was successfully formulated into a colloidal gel for extrusion through a direct inkjet writing printer. 3D-printed scaffolds promoted cellular attachment and proliferation, making them a promising material for customized, patient-specific tissue regenerative applications.

4.
Geroscience ; 45(3): 1933-1951, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37166526

RESUMO

Sodium glucose cotransporter-2 inhibitors (SGLT2is) promote urinary glucose excretion and decrease plasma glucose levels independent of insulin. Canagliflozin (CANA) is an SGLT2i, which is widely prescribed, to reduce cardiovascular complications, and as a second-line therapy after metformin in the treatment of type 2 diabetes mellitus. Despite the robust metabolic benefits, reductions in bone mineral density (BMD) and cortical fractures were reported for CANA-treated subjects. In collaboration with the National Institute on Aging (NIA)-sponsored Interventions Testing Program (ITP), we tested skeletal integrity of UM-HET3 mice fed control (137 mice) or CANA-containing diet (180 ppm, 156 mice) from 7 to 22 months of age. Micro-computed tomography (micro-CT) revealed that CANA treatment caused significant thinning of the femur mid-diaphyseal cortex in both male and female mice, did not affect trabecular bone architecture in the distal femur or the lumbar vertebra-5 in male mice, but was associated with thinning of the trabeculae at the distal femur in CANA-treated female mice. In male mice, CANA treatment is associated with significant reductions in cortical bone volumetric BMD by micro-CT, and by quantitative backscattered scanning electron microscopy. Raman microspectroscopy, taken at the femur mid-diaphyseal posterior cortex, showed significant reductions in the mineral/matrix ratio and an increased carbonate/phosphate ratio in CANA-treated male mice. These data were supported by thermogravimetric assay (TGA) showing significantly decreased mineral and increased carbonate content in CANA-treated male mice. Finally, the sintered remains of TGA were subjected to X-ray diffraction and showed significantly higher fraction of whitlockite, a calcium orthophosphate mineral, which has higher resorbability than hydroxyapatite. Overall, long-term CANA treatment compromised bone morphology and mineral composition of bones, which likely contribute to increased fracture risk seen with this drug.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Masculino , Feminino , Animais , Camundongos , Canagliflozina/farmacologia , Canagliflozina/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Microtomografia por Raio-X , Esqueleto
5.
Biomed Mater Eng ; 34(5): 439-458, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36744331

RESUMO

BACKGROUND: While autografts to date remain the "gold standard" for bone void fillers, synthetic bone grafts have garnered attention due to their favorable advantages such as ability to be tailored in terms of their physical and chemical properties. Bioactive glass (BG), an inorganic material, has the capacity to form a strong bond with bone by forming a bone-like apatite surface, enhancing osteogenesis. Coupled with additive manufacturing (3D printing) it is possible to maximize bone regenerative properties of the BG. OBJECTIVE: The objective of this study was to synthesize and characterize 3D printed mesoporous bioactive glass (MBG), BG 45S5, and compare to ß-Tricalcium phosphate (ß-TCP) based scaffolds; test cell viability and osteogenic differentiation on human osteoprogenitor cells in vitro. METHODS: MBG, BG 45S5, and ß-TCP were fabricated into colloidal gel suspensions, tested with a rheometer, and manufactured into scaffolds using a 3D direct-write micro-printer. The materials were characterized in terms of microstructure and composition with Thermogravimetric Analyzer/Differential Scanning Calorimeter (TGA/DSC), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Micro-Computed Tomography (µ-CT), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Mattauch-Herzog-Inductively Coupled Plasma-Mass Spectrometry (MH-ICP-MS). RESULTS: Scaffolds were tested for cell proliferation and osteogenic differentiation using human osteoprogenitor cells. Osteogenic media was used for differentiation, and immunocytochemistry for osteogenic markers Runx-2, Collagen-I, and Osteocalcin. The cell viability results after 7 days of culture yielded significantly higher (p < 0.05) results in ß-TCP scaffolds compared to BG 45S5 and MBG groups. CONCLUSION: All materials expressed osteogenic markers after 21 days of culture in expansion and osteogenic media.


Assuntos
Osteogênese , Alicerces Teciduais , Humanos , Alicerces Teciduais/química , Medicina Regenerativa , Microtomografia por Raio-X , Vidro/química , Cerâmica/química , Impressão Tridimensional
6.
Int J Esthet Dent ; 15(3): 344-354, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760928

RESUMO

AIM: Die silicone materials are used to build chairside composite restorations. The purpose of this study was to compare the flowability, dimension accuracy, and tear strength of four elastomeric die materials. MATERIAL AND METHODS: Materials were divided into four groups: Mach-2 (M2), Scan Die (SD), GrandioSO Inlay System (GIS), and Impregum-F (IM). Flowability analysis was carried out using the shark fin test (SFT). For dimension accuracy, impressions were taken from a premolar Class I preparation and an elastomeric model was cast. Composite resin restorations were built and positioned into the premolar for gap measurement. The mean gap length was divided into three levels: acceptable (A), not acceptable (NA), and misfit (M). For tear strength, strip specimens were made with a V-shaped notch (n = 6). The specimens were tested in a universal machine until tear. All data were analyzed statistically with a confidence interval of 95%. RESULTS: GIS showed the lowest flowability values, with no differences between IM, M2, and SD. For dimension accuracy, IM showed 100% 'A' gap values, followed by M2 (80%), SD (60%), and GIS (60%). For tear strength, IM showed the highest values, followed by M2, GIS, and SD. CONCLUSIONS: M2, SD, and IM had similar flowability, while GIS had the lowest. IM presented higher tear strength than M2, followed by GIS and SD. IM showed the highest degrees of acceptable gap filling, followed by M2.


Assuntos
Resinas Compostas , Restaurações Intracoronárias , Análise do Estresse Dentário , Teste de Materiais
7.
J Biomed Mater Res B Appl Biomater ; 108(5): 1868-1878, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31840930

RESUMO

Osteopenia and osteoporosis affect over 40 million US adults 50 years and older. Both diseases are strongly influenced by estrogen and nutritional-mineral deficiencies. This study investigates the efficacy of orally delivered synthetic-bone-mineral (SBM), a newly developed calcium phosphate based biomaterial, on reversing bone loss induced by these two critical deficiencies. Thirty 3-month-old female rats were randomly allocated to either control-sham surgery on normal diet; or one of the four experimental groups: Sham surgery on a low mineral diet (LMD), ovariectomized (OVX) on LMD, OVX on LMD with SBM with/without fluoride (F). The rats were sacrificed after 6 months, at 9-month-old. After 6 months, although all groups lost bone mineral density relative to controls, the supplemented OVX rats showed higher bone mineral density than their unsupplemented counterparts. The 2 SBM supplemented groups improved bone loading capacity by 28.1 and 35.4% compared to the OVX LMD group. Bones from supplemented rats exhibited higher inorganic/organic ratios. The addition of F did not have a significant influence on bone loss. Our findings suggest that SBM supplement is effective in maintaining bone health and offsetting the deleterious effects of estrogen and/or mineral deficiencies on bone density, microarchitecture, and strength.


Assuntos
Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/metabolismo , Osso e Ossos/efeitos dos fármacos , Fosfatos de Cálcio/metabolismo , Estrogênios/farmacologia , Minerais/farmacologia , Animais , Osso e Ossos/metabolismo , Dieta , Dietoterapia , Feminino , Humanos , Testes Mecânicos , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
8.
Mater Sci Eng C Mater Biol Appl ; 70(Pt 1): 408-417, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27770910

RESUMO

In this work, two solutions were developed: the first, rich in Ca2+, PO43- ions and the second, rich in Ca2+, PO43- and Mg2+, defined as Mg-modified precursor solution. For each Mg-modified precursor solution, the concentrations of Mg2+ ions were progressively increased by 5%, 10% and 15%wt. The aims of this research were to investigate the influence of magnesium ions substitution in calcium phosphate coatings on titanium surface and to evaluate these coatings by bioactivity assay in McCoy culture medium. The obtained coatings were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis, and the presence of Mg ions was confirmed by the inductively coupled plasma atomic emission spectroscopy (ICP) analysis. In vitro bioactivity assay in McCoy culture medium showed bioactivity after 14days in incubation for the HA and 10% Mg-monetite coatings. The high chemical stability of Mg-HA coatings was verified by the bioactivity assays, and no bone-like apatite deposition, characteristic of bioactivity, was observed for Mg-HA coatings, for the time period used in this study.


Assuntos
Álcalis/química , Apatitas/química , Fosfatos de Cálcio/química , Materiais Revestidos Biocompatíveis/química , Magnésio/química , Ácidos/química , Íons , Peso Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
J Biomed Mater Res A ; 104(7): 1622-32, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26914814

RESUMO

Calcium and other trace mineral supplements have previously demonstrated to safely improve bone quality. We hypothesize that our novel calcium-phosphate based biomaterial (SBM) preserves and promotes mandibular bone formation in male and female rats on mineral deficient diet (MD). Sixty Sprague-Dawley rats were randomly assigned to receive one of three diets (n = 10): basic diet (BD), MD or mineral deficient diet with 2% SBM. Rats were sacrificed after 6 months. Micro-computed tomography (µCT) was used to evaluate bone volume and 3D-microarchitecture while microradiography (Faxitron) was used to measure bone mineral density from different sections of the mandible. Results showed that bone quality varied with region, gender and diet. MD reduced bone mineral density (BMD) and volume and increased porosity. SBM preserved BMD and bone mineral content (BMC) in the alveolar bone and condyle in both genders. In the alveolar crest and mandibular body, while preserving more bone in males, SBM also significantly supplemented female bone. Results indicate that mineral deficiency leads to low bone mass in skeletally immature rats, comparatively more in males. Furthermore, SBM administered as a dietary supplement was effective in preventing mandibular bone loss in all subjects. This study suggests that the SBM preparation has potential use in minimizing low peak bone mass induced by mineral deficiency and related bone loss irrespective of gender. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1622-1632, 2016.


Assuntos
Materiais Biocompatíveis/farmacologia , Densidade Óssea/efeitos dos fármacos , Mandíbula/efeitos dos fármacos , Mandíbula/crescimento & desenvolvimento , Osteogênese/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Fosfatos de Cálcio/farmacologia , Cristalização , Dieta , Feminino , Masculino , Mandíbula/diagnóstico por imagem , Tamanho do Órgão/efeitos dos fármacos , Ratos Sprague-Dawley , Microtomografia por Raio-X
10.
J Prosthodont Res ; 60(2): 131-7, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26787534

RESUMO

PURPOSE: Osteoporosis contributes to impaired bone regeneration and remodeling through an imbalance of osteoblastic and osteoclastic activity, and can delay peri-implant bone formation after dental implant surgery, resulting in a prolonged treatment period. It poses several difficulties for individuals with large edentulous areas, and decreases their quality of life. Consequently, prompt postoperative placement of the final prosthesis is very important clinically. Peri-implant bone formation may be enhanced by systemic approaches, such as the use of osteoporosis supplements, to promote bone metabolism. We aimed to confirm whether intake of synthetic bone mineral (SBM), a supplement developed for osteoporosis, could effectively accelerate peri-implant bone formation in a rat model of osteoporosis. METHODS: Thirty-six 7-week-old ovariectomized female Wistar rats were randomly assigned to receive a standardized diet with or without SBM (Diet with SBM group and Diet without SBM group, respectively; n=18 for both). The rats underwent implant surgery at 9 weeks of age under general anesthesia. The main outcome measures, bone mineral density (BMD) and pull-out strength of the implant from the femur, were compared at 2 and 4 weeks after implantation using the Mann-Whitney U test. RESULTS: Pull-out strength and BMD in the Diet with SBM group were significantly greater than those in the Diet without SBM group at 2 and 4 weeks after implantation. CONCLUSIONS: This study demonstrated that SBM could be effective in accelerating peri-implant bone formation in osteoporosis.


Assuntos
Suplementos Nutricionais , Minerais/administração & dosagem , Osteogênese , Osteoporose/metabolismo , Animais , Densidade Óssea , Implantação Dentária , Modelos Animais de Doenças , Feminino , Ratos , Ratos Wistar
11.
J Hard Tissue Biol ; 25(3): 257-262, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28133434

RESUMO

The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improves peri-implant bone formation and bone micro architecture (BMA). SBM was used as an intervention experimental diet and AIN-93M was used as a control. The SBM was prepared by mixing dicalcium phosphate dihydrate (CaHPO4·2H2O) and magnesium and zinc chlorides (MgCl2 and ZnCl2, respectively), and hydrolyzed in double-distilled water containing dissolved potassium carbonate and sodium fluoride. All rats were randomly allocated into one of two groups: a control group was fed without SBM (n = 18) or an experimental group was fed with SBM (n = 18), at seven weeks old. At 9 weeks old, all rats underwent implant surgery on their femurs under general anesthesia. The implant was inserted into the insertion socket prepared at rats' femur to a depth of 2.5 mm by using a drill at 500 rpm. Nine rats in each group were randomly selected and euthanized at 2 weeks after implantation. The remaining nine rats in each group continued their diets, and were euthanized in the same manner at 4 weeks after implantation. The femur, including the implant, was removed from the body and implant was pulled out by an Instron universal testing machine. After the implant removal, BMA was evaluated by bone surface ratio (BS/BV), bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN), trabecular star volume (Vtr), and micro-CT images. BS/BV, BV/TV, TbTh and Vtr were significantly greater in the rats were fed with SBM than those were fed without SBM at 2 and 4 weeks after implantation (P < 0.05). The present results revealed that SBM improves the peri-implant formation and BMA, prominent with trabecular bone structure. The effect of SBM to improve secondary stability of the implant, and shortening the treatment period should be investigated in the future study.

12.
Acta Biomater ; 18: 9-20, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25575855

RESUMO

Various calcium phosphate based coatings have been evaluated for better bony integration of metallic implants and are currently being investigated to improve the surface bioactivity of polymeric scaffolds. The aim of this study was to evaluate the role of calcium phosphate coating and simultaneous delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the in vivo bone regeneration capacity of biodegradable, porous poly(propylene fumarate) (PPF) scaffolds. PPF scaffolds were coated with three different calcium phosphate formulations: magnesium-substituted ß-tricalcium phosphate (ß-TCMP), carbonated hydroxyapatite (synthetic bone mineral, SBM) and biphasic calcium phosphate (BCP). In vivo bone regeneration was evaluated by implantation of scaffolds in a critical-sized rabbit calvarial defect loaded with different doses of rhBMP-2. Our data demonstrated that scaffolds with each of the calcium phosphate coatings were capable of sustaining rhBMP-2 release and retained an open porous structure. After 6weeks of implantation, micro-computed tomography revealed that the rhBMP-2 dose had a significant effect on bone formation within the scaffolds and that the SBM-coated scaffolds regenerated significantly greater bone than BCP-coated scaffolds. Mechanical testing of the defects also indicated restoration of strength in the SBM and ß-TCMP with rhBMP-2 delivery. Histology results demonstrated bone growth immediately adjacent to the scaffold surface, indicating good osteointegration and osteoconductivity for coated scaffolds. The results obtained in this study suggest that the coated scaffold platform demonstrated a synergistic effect between calcium phosphate coatings and rhBMP-2 delivery and may provide a promising platform for the functional restoration of large bone defects.


Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Regeneração Óssea/efeitos dos fármacos , Fosfatos de Cálcio/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Fumaratos/farmacologia , Polipropilenos/farmacologia , Crânio/efeitos dos fármacos , Alicerces Teciduais/química , Fator de Crescimento Transformador beta/farmacologia , Animais , Preparações de Ação Retardada , Feminino , Humanos , Imageamento Tridimensional , Cinética , Porosidade , Coelhos , Proteínas Recombinantes/farmacologia , Crânio/diagnóstico por imagem , Espectrometria por Raios X , Microtomografia por Raio-X
13.
J Biomater Appl ; 27(7): 783-90, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22071355

RESUMO

OBJECTIVES: This study aimed to determine the efficacy of experimental calcium phosphate-based solutions (sCaP) containing fluoride (F), with and without zinc (Zn) ions on reducing susceptibility to acid dissolution and Streptococcus mutans (S. mutans) colonization of dentin surfaces. METHODS: Dentin sections were treated with double distilled water (control) and with sCaP solutions differing in pH and in F(-) and/or Zn(2+) ion concentrations. Solutions A (pH 7); B, C, and D (pH 5.5); solution C, twice Zn(2+) and F(-) ion concentration compared to B; solution D is similar to C but without Zn(2+). The dentin surfaces were characterized using scanning electron microscopy (SEM), x-ray diffraction, and Fourier Transform Infrared spectroscopy. Dissolution was determined in acidic buffer. Bacterial (S. mutans) attachment and growth were evaluated using SEM and Bioquant. Statistical analyses applied analysis of variance (ANOVA) and Duncan's multiple Range test. RESULTS: Compared to control, dentin surfaces treated with sCaP solutions showed: (a) occluded dentin tubules; (b)reduced susceptibility to acid dissolution; and (c) Zn(2+) ions were more effective than F(-) ions in inhibiting bacterial colonization. SIGNIFICANCE: Acidic sCaP containing both F and Zn ions have mineralizing, acid resistance, and antibacterial effects and may be potentially useful as a strategy against dentin caries formation and progression.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Dentina/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Ácidos/química , Aderência Bacteriana/efeitos dos fármacos , Dentina/química , Dentina/microbiologia , Dentina/ultraestrutura , Fluoretos/química , Fluoretos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Streptococcus mutans/crescimento & desenvolvimento , Propriedades de Superfície/efeitos dos fármacos , Zinco/química , Zinco/farmacologia
14.
Arch Oral Biol ; 57(9): 1264-73, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22424637

RESUMO

UNLABELLED: Osteoporosis affects the craniofacial and oral structures and has been associated with periodontal bone loss, tooth loss and reduced jaw bone mass. OBJECTIVE: This study aimed to test the therapeutic efficacy of synthetic bone mineral (SBM) in minimizing alveolar bone loss induced by mineral deficiency in a rat model. SBM consists of a calcium carbonate apatite (similar to bone apatite) matrix incorporating magnesium, zinc, and fluoride ions. DESIGN: Thirty female Sprague Dawley rats (2 months old) were randomly distributed into 3 groups (10 rats per group): GA (control), on basic diet; GB, on mineral deficient (MD) diet; and GC, on MD+SBM. The rats were sacrificed after 3 months, the jawbones were isolated and the soft tissues removed. Bone density was determined using X-ray radiography (Faxitron); mandibular cortical width, panoramic mandibular index, and alveolar resorption degree (M/M ratio) using BioquantOsteo; and bone micro-architecture micro-computed tomography and scanning electron microscopy. RESULTS: Compared to control (GA), the rats on MD diet (GB) experienced significant mandibular bone loss while the rats on MD+SBM diet (GC) experienced significantly less bone loss compared to the GB group. CONCLUSION: SBM, administered orally, may have the potential as an osteoporosis therapeutic agent in minimizing or preventing alveolar bone loss induced by mineral deficiency.


Assuntos
Perda do Osso Alveolar/etiologia , Apatitas/uso terapêutico , Conservadores da Densidade Óssea/uso terapêutico , Carbonato de Cálcio/uso terapêutico , Deficiências Nutricionais/complicações , Minerais , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/tratamento farmacológico , Animais , Densidade Óssea/efeitos dos fármacos , Fosfatos de Cálcio/uso terapêutico , Carbonatos/uso terapêutico , Cloretos/uso terapêutico , Modelos Animais de Doenças , Feminino , Imageamento Tridimensional/métodos , Cloreto de Magnésio/uso terapêutico , Doenças Mandibulares/diagnóstico por imagem , Doenças Mandibulares/tratamento farmacológico , Doenças Mandibulares/etiologia , Microrradiografia , Microscopia Eletrônica de Varredura , Osteoporose/etiologia , Potássio/uso terapêutico , Radiografia Panorâmica , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Fluoreto de Sódio/uso terapêutico , Microtomografia por Raio-X/métodos , Compostos de Zinco/uso terapêutico
15.
Tissue Eng Part A ; 15(3): 635-43, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18759673

RESUMO

The use of biomaterials to replace lost bone has been a common practice for decades. More recently, the demands for bone repair and regeneration have pushed research into the use of cultured cells and growth factors in association with these materials. Here we report a novel approach to engineer new bone using a transient cartilage scaffold to induce endochondral ossification. Chondrocyte/chitosan scaffolds (both a transient cartilage scaffold-experimental-and a permanent cartilage scaffold-control) were prepared and implanted subcutaneously in nude mice. Bone formation was evaluated over a period of 5 months. Mineralization was assessed by Faxitron, micro computed tomography, backscatter electrons, and Fourier transform infrared spectroscopy analyses. Histological analysis provided further information on tissue changes in and around the implanted scaffolds. The deposition of ectopic bone was detected in the surface of the experimental implants as early as 1 month after implantation. After 3 months, bone trabeculae and bone marrow cavities were formed inside the scaffolds. The bone deposited was similar to the bone of the mice vertebra. Interestingly, no bone formation was observed in control implants. In conclusion, an engineered transient cartilage template carries all the signals necessary to induce endochondral bone formation in vivo.


Assuntos
Osso e Ossos/fisiologia , Cartilagem/fisiologia , Engenharia Tecidual/métodos , Animais , Osso e Ossos/efeitos dos fármacos , Calcificação Fisiológica/efeitos dos fármacos , Cartilagem/efeitos dos fármacos , Embrião de Galinha , Quitosana/farmacologia , Condrócitos/citologia , Condrócitos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Nus , Microscopia Eletrônica de Varredura , Minerais/metabolismo , Implantação de Prótese , Espectroscopia de Infravermelho com Transformada de Fourier , Alicerces Teciduais
16.
Am J Dent ; 16(3): 155-60, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12967067

RESUMO

PURPOSE: To test the hypothesis that anticalculus agents cannot completely inhibit calculus formation but can influence the types of calcium phosphate which form, i.e., they can influence the composition of the inorganic component of human dental calculus (HDC). MATERIALS AND METHODS: The composition of HDC specimens obtained from a 16-week multi-center clinical study using three regimens were analyzed, investigators blinded. The treatment regimens were: (a) standard dentifrice (SD), (b) pyrophosphate antitartar dentifrice, and (c) SD with Tartar Control Listerine Antiseptic mouthrinse (containing essential oils and 0.09% zinc chloride). 25 individual samples and eight pooled samples from each group were analyzed using X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. RESULTS: (1) relative frequency of occurrence for: (a) bacteria: Group A = 100%, Group B = 60%, and Group C = 25%; (b) Carbonate hydroxyapatite (CHA): Groups A, B, and C = 100%; (c) dicalcium phosphate dihydrate (DCPD): Group A = 55%; Group B = 45%; Group C = 80%; (2) The relative amount of DCPD is inversely proportional to that of CHA in HDC: the higher the amount of DCPD, the lower the amount of CHA. Group C regimen with essential oil/ZnCl2 mouthrinse and standard dentifrice showed a significant anti-microbial effect and favored the formation of DCPD, the most soluble Ca-P.


Assuntos
Cloretos/uso terapêutico , Cálculos Dentários/química , Antissépticos Bucais/uso terapêutico , Óleos Voláteis/uso terapêutico , Compostos de Zinco/uso terapêutico , Anti-Infecciosos Locais/uso terapêutico , Bactérias/ultraestrutura , Fosfatos de Cálcio/análise , Fosfatos de Cálcio/classificação , Dentifrícios/uso terapêutico , Difosfatos/uso terapêutico , Método Duplo-Cego , Durapatita/análise , Humanos , Microscopia Eletrônica de Varredura , Compostos Orgânicos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
17.
Dent Clin North Am ; 47(1): 57-65, viii-ix, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12519005

RESUMO

According to available limited epidemiology studies, the prevalence of oral disease is much greater in American minorities (Blacks, Hisoanics, Asians, Native Americans) than in the majority population. The purpose of this article is to describe the oral health status and current treatment needs of a group of African-American (AA) adults in New York City. The convenience sample consisted of 951 AA adults (M = 662, F = 289) recruited through community- or faith-based institutions, and the in-house screening conducted by the Research Center for Minority Oral Health in dedicated dental clinics at the New York University College of Dentistry. The age of participants ranged from 18 to 64 years, (mean age 42, SD = 11.04). Calibrated examiners performed the clinical examinations utilizing National Institute of Dental and Craniofacial Research (NIDCR) diagnostic criteria. The DMFT, DMFS, DFS, and %D/DFS indices were obtained and results indicated the following. For the 18 to 34 age group (n = 246), the mean DMFT was 8.83, the mean DMFS was 21.36, the mean DFS was 12.10, and the mean %D/DFS was 30. For the 35 to 49 age group (n = 523), the mean DMFT was 14.03, the mean DMFS was 48.21, the mean DFS was 18.76, and the mean %D/DFS was 29. For the 50 to 64 age group (n = 182), the mean DMFT was 15.38, the mean DMFS was 64.48, the mean DFS was 17.98, and the mean %D/DFS was 29. For all age groups, the findings indicated a high prevalence of dental decay and greater number of filled surfaces compared with the United States national surveys.


Assuntos
População Negra , Cárie Dentária/etnologia , Adolescente , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Distribuição por Idade , Índice CPO , Feminino , Humanos , Masculino , Má Oclusão/etnologia , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Índice de Higiene Oral , Doenças Periodontais/etnologia , Prevalência , Distribuição por Sexo , Fatores Socioeconômicos
18.
Dent Clin North Am ; 47(1): 103-14, x, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12519008

RESUMO

Disparities in the prevalence and severity of destructive periodontal diseases have been reported for American minority populations and have raised the following questions. Are differences in destructive periodontal disease prevalence and severity due to genetic or other confounding variables associated with ethnicity race? Do risk factors for destructive periodontal diseases differ among American minority populations or differ from the population at large? Answers to these questions will have profound impact on the direction of future research and the allocation of resources to address disparities in destructive periodontal diseases in American minority populations. Risk assessment studies that examined a set of clinical, demographic, immunologic, and microbiologic parameters of Asian Americans, African Americans, and Hispanic Americans resident in the greater New York City region suggest that occupational status, monitored as a surrogate variable for socioeconomic status, may be a more robust risk factor than ethnicity/race for destructive periodontal diseases in these populations.


Assuntos
Grupos Minoritários/estatística & dados numéricos , Doenças Periodontais/etnologia , Adulto , Idoso , Progressão da Doença , Feminino , Humanos , Incidência , Masculino , Doenças Periodontais/microbiologia , Prevalência , Fatores de Risco , Fatores Socioeconômicos , Estados Unidos/epidemiologia
19.
J Clin Periodontol ; 30(12): 1075-83, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15002894

RESUMO

BACKGROUND, AIMS: Differences in prevalence, severity and risk factors for destructive periodontal diseases have been reported for ethnic/racial groups. However, it is not certain whether this disparity is due to ethnicity/race or factors associated with ethnicity/race. Therefore, the present study addressed whether the rates of disease progression and clinical and demographic factors associated with disease progression varied among three ethnic/racial groups. METHODS: The study population consisted of 53 Asian-, 69 African- and 62 Hispanic-Americans. Clinical measurements included probing depth, attachment level, gingival erythema, bleeding upon probing, suppuration and plaque. Disease progression was defined as a > 2 mm loss of attachment 2 months post baseline. The demographic variables examined included occupational status, report of a private dentist, years resident in the United States and smoking history. RESULTS: The rate of attachment loss for the entire population was 0.04 mm or 0.24 mm/year. No significant differences were found among the three ethnic/racial groups. Variables associated with subsequent attachment loss for the entire population were age, male gender, mean whole-mouth plaque, erythema, bleeding upon probing, suppuration, attachment loss and probing depth, and belonging to the "unskilled" occupational group. No differences in risk profiles were found among the 3 ethnic/racial groups. Using stepwise logistic regression analysis, a model was developed to relate the clinical and demographic variables examined with subsequent attachment loss. The model indicated that prior attachment loss, gingival erythema, suppuration, being a current smoker and belonging to the "unskilled" occupational group conferred high risk of > 1 site of attachment loss of > 2 mm. CONCLUSIONS: The results of this study suggest that variables associated with ethnicity/race, such as occupational status, are largely responsible for the observed disparity in destructive periodontal disease progression in these populations.


Assuntos
Etnicidade , Grupos Minoritários , Doenças Periodontais/fisiopatologia , Saúde da População Urbana , Adulto , Negro ou Afro-Americano , Fatores Etários , Idoso , Asiático , Progressão da Doença , Feminino , Seguimentos , Hemorragia Gengival/fisiopatologia , Gengivite/fisiopatologia , Hispânico ou Latino , Humanos , Masculino , Pessoa de Meia-Idade , Ocupações , Perda da Inserção Periodontal/fisiopatologia , Bolsa Periodontal/fisiopatologia , Fatores Sexuais , Fumar , Estados Unidos
20.
J Periodontal Res ; 37(2): 132-46, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12009183

RESUMO

Differences in periodontal disease prevalence, severity, subgingival microflora and host immune response have been reported for various ethnic/racial groups, which implies that risk factors for destructive periodontal disease progression may also vary in these populations. As it is possible that these differences may be due to confounding variables other than ethnicity/race, we have measured serum IgG antibody response to six periodontal pathogens, and compared these data with microbiological, clinical and demographic parameters in three urban minority populations. The study population consisted of 23 Asiatic, 48 African-American and 37 Hispanic subjects, who were resident in the greater New York region. Clinical indices that were recorded included pocket depth, attachment level, gingival erythema, bleeding upon probing, suppuration and supragingival plaque. Attachment level measurements were taken twice at each visit, and the difference between the means of pairs of measurements taken at baseline and two months later was used to determine disease progression. Subgingival microbiological species were identified and enumerated using DNA-DNA checkerboard hybridization. Serum IgG antibody levels to Actinobacillus actinomycetemcomitans serotyopes a and b, Bacteroides forsythus, Campylobacter rectus, Porphyromonas gingivalis and Prevotella intermedia were measured by enzyme-linked immunosorbant assay (ELISA). Mean serum IgG antibody to P. gingivalis was found to be higher in the African-American group, while IgG antibody to B. forsythus was lower in the Hispanic group. However, the African-American group also had greater mean probing depth, attachment loss, number of missing teeth and numbers of individuals within the unskilled occupational group. When the data were analyzed by occupational status, mean serum IgG antibody to P. gingivalis increased from professional to skilled to unskilled groups. For the entire study population, prior disease and subsequent attachment loss were associated with elevated serum IgG antibody to P. gingivalis. Increasing pocket depth, attachment level, gingival erythema and age were also positively correlated with serum IgG antibody to P. gingivalis, but not with serum IgG antibody to the other five subgingival species. No correlation was found between whole-mouth bacterial levels and homologous serum IgG antibody levels. These results suggest that elevated serum IgG antibody to P. gingivalis reflects destructive periodontal disease status, and may be considered a risk factor for disease progression in these ethnic/racial populations. In addition, although differences in serum IgG antibody profiles to subgingival species were found among the three ethnic/racial groups, environmental and socioeconomic variables may have a greater influence on serum IgG antibody levels in these populations.


Assuntos
Anticorpos Antibacterianos/sangue , Imunoglobulina G/sangue , Grupos Minoritários , Doenças Periodontais/microbiologia , Adulto , Negro ou Afro-Americano , Fatores Etários , Idoso , Aggregatibacter actinomycetemcomitans/imunologia , Asiático , Bacteroides/imunologia , Campylobacter/imunologia , Distribuição de Qui-Quadrado , Índice de Placa Dentária , Progressão da Doença , Feminino , Seguimentos , Hemorragia Gengival/classificação , Gengivite/classificação , Hispânico ou Latino , Humanos , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque , Ocupações , Razão de Chances , Perda da Inserção Periodontal/classificação , Doenças Periodontais/classificação , Bolsa Periodontal/classificação , Porphyromonas gingivalis/imunologia , Prevotella intermedia/imunologia , Fatores de Risco , Estatísticas não Paramétricas
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