Résumé
Abstract Mining is vital for human sustenance and a crucial sector in the state economy. However, its impacts on the environment and biodiversity cannot be underestimated. Which are potent to the attract governments attention. Environment and wildlife are subject to the harmful impacts of mining and its related activities. In this study, districts, namely Mardan and Mohmand have been targeted with respect to mining impacts. The assessment was carried out on wildlife adversely affected by the mining sector. The fauna has been keenly observed to bring the calculated risks and threat perception of the regional wildlife. Total 9 species of mammals, 21 species of birds, were recorded in District Mardan. While in District Mohmand 2 species of mammals, 9 species of birds, and 4 species of reptiles were studied. The Study explored that mining primarily responsible for land degradation. Which lead to food and agriculture losses. Several other factors like blasting, pollution, hunting, deforestation, habitat loss was also observed. Deforestation surfaced one of the major causes for extinction of fauna in the said region. preemptive measures are needed to seize the man-made catastrophe.
Resumo A mineração é vital para o sustento humano e um setor crucial na economia do Estado. No entanto, seus impactos sobre o meio ambiente e a biodiversidade não podem ser subestimados, visto serem potentes para atrair a atenção do governo. O meio ambiente e a vida selvagem estão sujeitos aos impactos prejudiciais da mineração e de suas atividades relacionadas. Neste estudo, os distritos, nomeadamente Mardan e Mohmand, foram selecionados no que diz respeito aos impactos da mineração. A avaliação foi realizada em animais selvagens afetados negativamente pelo setor de mineração. A fauna tem sido observada atentamente para trazer os riscos calculados e a percepção de ameaça à vida selvagem regional. Um total de nove espécies de mamíferos, 21 espécies de pássaros, foi registrado no Distrito Mardan. Enquanto no Distrito Mohmand, duas espécies de mamíferos, nove espécies de pássaros e quatro espécies de répteis foram estudadas. O estudo explorou essa mineração que é principalmente responsável pela degradação do solo, acarretando perdas de alimentos e na agricultura. Vários outros fatores como explosões, poluição, caça, desmatamento, perda de habitat também foram observados. O desmatamento veio à tona como uma das principais causas de extinção da fauna da região, e tem-se que medidas preventivas são necessárias para dimensionar a catástrofe provocada pelo homem.
Résumé
Abstract Mining is vital for human sustenance and a crucial sector in the state economy. However, its impacts on the environment and biodiversity cannot be underestimated. Which are potent to the attract government's attention. Environment and wildlife are subject to the harmful impacts of mining and its related activities. In this study, districts, namely Mardan and Mohmand have been targeted with respect to mining impacts. The assessment was carried out on wildlife adversely affected by the mining sector. The fauna has been keenly observed to bring the calculated risks and threat perception of the regional wildlife. Total 9 species of mammals, 21 species of birds, were recorded in District Mardan. While in District Mohmand 2 species of mammals, 9 species of birds, and 4 species of reptiles were studied. The Study explored that mining primarily responsible for land degradation. Which lead to food and agriculture losses. Several other factors like blasting, pollution, hunting, deforestation, habitat loss was also observed. Deforestation surfaced one of the major causes for extinction of fauna in the said region. preemptive measures are needed to seize the man-made catastrophe.
Resumo A mineração é vital para o sustento humano e um setor crucial na economia do Estado. No entanto, seus impactos sobre o meio ambiente e a biodiversidade não podem ser subestimados, visto serem potentes para atrair a atenção do governo. O meio ambiente e a vida selvagem estão sujeitos aos impactos prejudiciais da mineração e de suas atividades relacionadas. Neste estudo, os distritos, nomeadamente Mardan e Mohmand, foram selecionados no que diz respeito aos impactos da mineração. A avaliação foi realizada em animais selvagens afetados negativamente pelo setor de mineração. A fauna tem sido observada atentamente para trazer os riscos calculados e a percepção de ameaça à vida selvagem regional. Um total de nove espécies de mamíferos, 21 espécies de pássaros, foi registrado no Distrito Mardan. Enquanto no Distrito Mohmand, duas espécies de mamíferos, nove espécies de pássaros e quatro espécies de répteis foram estudadas. O estudo explorou essa mineração que é principalmente responsável pela degradação do solo, acarretando perdas de alimentos e na agricultura. Vários outros fatores como explosões, poluição, caça, desmatamento, perda de habitat também foram observados. O desmatamento veio à tona como uma das principais causas de extinção da fauna da região, e tem-se que medidas preventivas são necessárias para dimensionar a catástrofe provocada pelo homem.
Sujets)
Humains , Animaux , Biodiversité , Animaux sauvages , Mine , PakistanRésumé
BACKGROUND: Any surface treatments should Improve the bond strength of yttria-stabilized tetragonal zlrconia polycrystal ceramics without damaging the original strength. Currently, there is no Information about the influence of glaze technology on the bond strength of yttria-stabilized tetragonal zlrconia polycrystal ceramics, and its Influence on the material strength Is unclear. OBJECTIVE: To evaluate the effect of glaze technology on the mechanical behavior of yttria-stabilized tetragonal zlrconia polycrystal ceramics and on the bond strength with resin cements. METHODS: Yttria-stabilized tetragonal zlrconia polycrystal ceramics specimens were prepared and randomly divided into four groups: group A: the surface was not treated; group B: sandblasting with 110 urn Al203 particles; group C: glaze + hydrofluoric acid etching; group D: glaze + hydrofluoric acid etching + sllanlzation. The surface morphology, surface roughness, phase transformation, elemental composition, shear bond strength and flexural strength of zlrconia specimens after surface treatments were tested. RESULTS AND CONCLUSION: (1) The surface roughness of treatment groups increased obviously, whose descending order was group C (0.62±0.01) um > group D (0.55±0.02) um > group B (0.11±0.02) um > group A (0.05±0.01) urn (p 0.05). (6) The effect of glaze technology on improving the flexural strength of yttria-stabilized tetragonal zirconia polycrystal ceramics is not as obvious as that of sandblasting, but the bond strength between tetragonal zirconia polycrystal ceramics and resin cements can be significantly Improved with hydrofluoric acid etching and silanization after glaze.
Résumé
The objective of this study was to fabricate hydroxyapatite (HA) containing titania layer by HA blasting and anodization method to obtain advantages of both methods and evaluated biocompatibility. To fabricate the HA containing titania layer on titanium, HA blasting treatment was performed followed by microarc oxidation (MAO) using the electrolyte solution of 0.04 M β-glycerol phosphate disodium salt n-hydrate and 0.4 M calcium acetate n-hydrate on the condition of various applied voltages (100, 150, 200, 250 V) for 3 minutes. The experimental group was divided according to the surface treatment procedure: SM (simple machined polishing treatment), HA, MAO, HA+MAO 100, HA+MAO 150, HA+MAO 200, HA+ MAO 250. The wettability of surface was observed by contact angle measurement. Biocompatibility was evaluated by cell adhesion, and cell differentiation including alkaline phosphatase activity and calcium concentration with MC3T3-E1 cells. The porous titanium oxide containing HA was formed at 150 and 200 V. These surfaces had a more hydrophilic characteristic. Biocompatibility was demonstrated that HA·titania composite layer on titanium showed enhanced cell adhesion, and cell differentiation. Therefore, these results suggested that HA containing titania layer on titanium was improved biological properties that could be applied as material for dental implant system.
Sujets)
Phosphatase alcaline , Calcium , Adhérence cellulaire , Différenciation cellulaire , Implants dentaires , Durapatite , Méthodes , Monoamine oxidase , Titane , MouillabilitéRésumé
Context: Bonding procedures are time consuming and debonding of brackets is a common problem encountered in orthodontics. Aims: The purpose of this in vitro study was to evaluate the shear bond strength (SBS) with different enamel pretreatment (acid etching, air abrasion, and bur abrasion) to enhance the bonding performance. Subjects and Methods: A total of 60 extracted premolars for orthodontic purposes were randomly assigned to three groups based on conditioning method: Group I ‑ conventional etching with 37% phosphoric acid; Group II ‑ air abrasion with 50 μm aluminum oxide; and Group III ‑ bur abrasion with diamond fissure (#330, MANI, Dia‑Burs, New Jersey, USA). After storing the specimens for 24 h in distilled water at 37°C, SBS was measured with Universal testing machine (Lloyd Universal testing machine‑Model No. L.R 100K, UK). The shear force at a crosshead speed of 1 mm/min was transmitted to brackets. The adhesive remnant index (ARIs) scores were recorded after bracket failure. Statistical Analysis Used: Descriptive statistics, multiple comparisons of the SBS of different groups, were performed by analysis of variance. The Tukey’s test was used to evaluate differences in ARI scores between groups. All statistical evaluations were calculated using the Statistical Package for Social Sciences Windows, release 10.0.0 (SPSS Inc., Chicago, Illinois, USA). Results: The analysis of SBS variance (P < 0.01) and Chi‑square test of ARIs scores (P < 0.01) revealed significant differences among three groups tested. The SBS in Group I (mean: 8.822 ± 0.92 MPa) and Group III (mean: 6.015 ± 0.87 MPa) was significantly higher than Group II (mean: 3.824 ± 0.57 MPa). The ARI was used to evaluate the residual adhesive on the enamel after bracket removal. The Tukey’s test was used to evaluate differences in the ARI scores among the groups. Conclusions: The current findings indicate that enamel surface preparation using bur abrasion results in a significant higher than air abrasion; within the limitations of this study recommend bur abrasion as a viable alternative to acid etching.
Sujets)
Collage dentaire/méthodes , Émail dentaire/effets des médicaments et des substances chimiques , Mordançage/méthodes , Analyse du stress dentaire , Brackets orthodontiquesRésumé
PURPOSE: This study compares the prognosis (the survival rate and marginal bone loss) of resorbable blasting media (RBM) surface implants and sandblasting with large-grit and acid-etching (SLA) surface implants in the early loading. METHODS: This study targeted 123 patients treated by implants installation from January 2008 to March 2010. The loading was initiated in the maxilla within three to four months and in the mandible within one to two months. The types of restoration were single crown and fixed partial prosthesis. Those functioned over one year. The implants were classified by the surface of implants as Group 1: RBM surface (GS III; OSSTEM, Busan, Korea) and, Group 2: SLA surface (Superline; Dentium, Seoul, Korea). The groups were categorized by maxilla and mandible and compared by survival rate, marginal bone loss through clinical records evaluation, and radiographic measurements. RESULTS: The marginal bone loss in the maxilla was 0.14+/-0.34 mm (Group 1) and 0.30+/-0.37 mm (Group 2), a statistically significant difference (P 0.05). There was no significant difference of marginal bone loss between maxilla and mandible by groups. During observation there was no implant failure, a survival rate of 100%. CONCLUSION: Both surfaces showed an excellent survival rate, and the marginal bone loss was not substantial.
Sujets)
Humains , Études de cohortes , Couronnes , Pose immédiate d'implant dentaire , Mandibule , Maxillaire , Pronostic , Prothèses et implants , Études rétrospectives , Séoul , Taux de survieRésumé
PURPOSE: This study was conducted to evaluate the roughness and surface alternations of three differently blasted titanium discs treated by Nd: YVO4 Laser irradiation in different conditions. MATERIALS AND METHODS: Thirty commercially pure titanium discs were prepared and divided into three groups. Each group was consisted of 10 samples and blasted by ZrO2 (zirconium dioxide), Al2O3 (aluminum oxide), and RBM (resorbable blasted media). All the samples were degreased by ultrasonic cleaner afterward. Nine different conditions were established by changing scanning speed (100, 300, 500 mm/s) and repetition rate (5, 15, 35 kHz) of Nd: YVO4 Laser (Laser Pro D-20, Laserval Korea(R) Seoul, South Korea). After laser irradiation, a scanning electron microscope, X-ray diffraction analysis, energy dispersive X-ray spectroscopic analysis, and surface roughness analysis were used to assess the roughness and surface alternations of the samples. RESULTS: According to a scanning electron microscope (SEM), titanium discs treated with laser irradiation showed characteristic patterns in contrast to the control which showed irregular patterns. According to the X-ray diffraction analysis, only Al2O3 group showed its own peak. The oxidation tendency and surface roughness of titanium were similar to the control in the energy dispersive X-ray spectroscopic analysis. The surface roughness was inversely proportional to the scanning speed, whereas proportional to the repetition rate of Nd: YVO4. CONCLUSION: The surface microstructures and roughness of the test discs were modified by the radiation of Nd: YVO4 laser. Therefore, laser irradiation could be considered one of the methods to modify implant surfaces for the enhancement of osseointegration.
Sujets)
Électrons , Ostéo-intégration , Projets pilotes , Propriétés de surface , Titane , Science des ultrasons , Diffraction des rayons XRésumé
An important parameter for the clinical success of dental implants is the formation of direct contact between the implant and surrounding bone, whose quality is directly influenced by the implant surface roughness. A screw-shaped design and a surface with an average roughness of Sa of 1-2 µm showed a better result. The combination of blasting and etching has been a commonly used surface treatment technique. The versatility of this type of treatment allows for a wide variation in the procedures in order to obtain the desired roughness. OBJECTIVES: To compare the roughness values and morphological characteristics of 04 brands of implants, using the same type of surface treatment. In addition, to compare the results among brands, in order to assess whether the type of treatment determines the values and the characteristics of implant surface roughness. MATERIAL AND METHODS: Three implants were purchased directly from each selected company in the market, i.e., 03 Brazilian companies (Biomet 3i of Brazil, Neodent and Titaniumfix) and 01 Korean company (Oneplant). The quantitative or numerical characterization of the roughness was performed using an interferometer. The qualitative analysis of the surface topography obtained with the treatment was analyzed using scanning electron microscopy images. RESULTS: The evaluated implants showed a significant variation in roughness values: Sa for Oneplant was 1.01 µm; Titaniumfix reached 0.90 µm; implants from Neodent 0.67 µm, and Biomet 3i of Brazil 0.53 µm. Moreover, the SEM images showed very different patterns for the surfaces examined. CONCCLUSIONS: The surface treatment alone is not able to determine the roughness values and characteristics.
Sujets)
Humains , Implants dentaires , Pose d'implant dentaire endo-osseux/méthodes , Titane/composition chimique , Mordançage à l'acide , Analyse de variance , Test de matériaux , Microscopie électronique à balayage , Valeurs de référence , Statistique non paramétrique , Propriétés de surfaceRésumé
OBJECTIVE: Polyaxial pedicle screws are a safe, useful adjunct to transpedicular fixation. However, the large screw head size can cause soft tissue irritation, high rod positioning, and facet joint injury. However, the mechanical resistance provided by small and low profile pedicle screws is very limited. We therefore developed a novel, low profile pedicle screw using grooving and blasting treatment that is able to resist a high compression bending load. METHODS: We evaluated the compression bending force to displacement and yield loads for seven different screw head types that differed with regard to their groove intervals and whether or not they had been blasted. RESULTS: The rank order of screw types that had the greatest compression bending force to displacement was as follows: (1) universal polyaxial, (2) low polyaxial with 0.1mm grooves and blasting, (3) low polyaxial with blasting, (4) low polyaxial with 0.15mm grooves and blasting, (5) low polyaxial with 0.05mm grooves and blasting, (6) low polyaxial with 0.05mm grooves, (7) and low polyaxial. Low polyaxial screws with 0.1mm grooves and blasting had the maximum yield load and highest compression bending force to displacement of all seven polyaxial screw head systems evaluated. CONCLUSION: Blasting and grooving treatment of pedicle screw heads resulted in screw heads with a high yield load and compression bending force relative to displacement because of increased friction. Low polyaxial pedicle screws with 0.1 mm grooves treated by blasting have mechanical characteristics similar to those of universal polyaxial pedicle screws.
Sujets)
Vis orthopédiques , Collodion , Déplacement psychologique , Friction , Tête , Articulation zygapophysaireRésumé
OBJECTIVE: Polyaxial pedicle screws are a safe, useful adjunct to transpedicular fixation. However, the large screw head size can cause soft tissue irritation, high rod positioning, and facet joint injury. However, the mechanical resistance provided by small and low profile pedicle screws is very limited. We therefore developed a novel, low profile pedicle screw using grooving and blasting treatment that is able to resist a high compression bending load. METHODS: We evaluated the compression bending force to displacement and yield loads for seven different screw head types that differed with regard to their groove intervals and whether or not they had been blasted. RESULTS: The rank order of screw types that had the greatest compression bending force to displacement was as follows: (1) universal polyaxial, (2) low polyaxial with 0.1mm grooves and blasting, (3) low polyaxial with blasting, (4) low polyaxial with 0.15mm grooves and blasting, (5) low polyaxial with 0.05mm grooves and blasting, (6) low polyaxial with 0.05mm grooves, (7) and low polyaxial. Low polyaxial screws with 0.1mm grooves and blasting had the maximum yield load and highest compression bending force to displacement of all seven polyaxial screw head systems evaluated. CONCLUSION: Blasting and grooving treatment of pedicle screw heads resulted in screw heads with a high yield load and compression bending force relative to displacement because of increased friction. Low polyaxial pedicle screws with 0.1 mm grooves treated by blasting have mechanical characteristics similar to those of universal polyaxial pedicle screws.
Sujets)
Vis orthopédiques , Collodion , Déplacement psychologique , Friction , Tête , Articulation zygapophysaireRésumé
OBJECTIVE: This study examined the potential of the in vitro osteogenesis of microtopographically modified surfaces, RBM (resorbable blasting media) surfaces, which generate hydroxyapatite grit-blasting. METHODS: RBM surfaces were modified hydroxyapatite grit-blasting to produce microtopographically modified surfaces and the surface morphology, roughness or elements were examined. To investigate the potential of the in vitro osteogenesis, the osteoblastic cell adhesion, proliferation, and differentiation were examined using the human osteoblast-like cell line, MG-63 cells. Osteoblastic cell proliferation was examined as a function of time. In addition, osteoblastic cell differentiation was verified using four different methods of an ALP activity assay, a mineralization assay using alizarin red-s staining, and gene expression of osteoblastic differentiation marker using RT-PCR or ELISA. RESULTS: Osteoblastic cell adhesion, proliferation and ALP activity was elevated on the RBM surfaces compared to the machined group. The cells exhibited a high level of gene expression of the osteoblastic differentiation makers (osteonectin, type I collagen, Runx-2, osterix). imilar data was represented in the ELISA produced similar results in that the RBM surface increased the level of osteocalcin, osteopontin, TGF-beta1 and PGE2 secretion, which was known to stimulate the osteogenesis. Moreover, alizarin red-s staining revealed significantly more mineralized nodules on the RBM surfaces than the machined discs. CONCLUSION: RBM surfaces modified with hydroxyapatite grit-blasting stimulate the in vitro osteogenesis of MG-63 cells and may accelerate bone formation and increase bone-implant contact.
Sujets)
Humains , Anthraquinones , Adhérence cellulaire , Différenciation cellulaire , Lignée cellulaire , Prolifération cellulaire , Collagène de type I , Dinoprostone , Durapatite , Test ELISA , Expression des gènes , Ostéo-intégration , Ostéoblastes , Ostéocalcine , Ostéogenèse , Ostéopontine , Facteur de croissance transformant bêta-1Résumé
PURPOSE: The purpose of this research is to study about initial adhesion, proliferation and activation of osteoblast to titanium surface treated with machined, hydroxyapatite coating, resorbable blast material blasting and anodizing method. MATERIAL AND METHODS: After treating the titanium surface of each block with machined, impurities were removed and sterilized. The number of cells attached from cultured osteoblast of respective experimental groups were measured at 1, 4, 7, and 14day and alkaline phosphatase, calcium, and inorganic phosphate concentration of cultured solution was measured. RESULT: Anodizing group showed the highest rate of cell attachment and proliferation activity. RBM treated group showed the highest increasing on their alkaline phosphatase activity, on the calcium apposition, on inorganic phosphate apposition of 1 and 4 days in cultured osteoblast to compare with other groups. CONCLUSION: On the basis of these findings, we conclude that surface modification of titanium was profoundly effected on the attachment, proliferation and activation of osteoblast in initial stage osseointegration.
Sujets)
Phosphatase alcaline , Calcium , Durapatite , Ostéo-intégration , Ostéoblastes , Caractéristiques de la population , TitaneRésumé
Recently, immediately after losing teeth, implant placement has been greatly attempted. Implant can help restoration of tooth functions within short time. This study was an attempt to examine the extent of osseointergation when the implants will be placed immediately after teeth extraction using domestic implant systems. Implants were inserted in beagle dogs and evaluated the clinical, radiological, histological and histomorphometric assay at 6 weeks and 12 weeks. For experimental materials, STAGE-1(R)(4.1x8mm, Lifecore, USA), SS-III(R)(4.0x8mm, OSSTEM, Korea) and IFI(R)(4.0x8 mm, DIO, Korea) implants treated with RBM were placed. All the placed site showed normal results without fail and inflammation clinically and radiologically. As a result of measurement by periotest, it showed -2 ~ -5 and stable status comprehensively. There was no statistically significant difference among implants(p<0.05). Bone tissue adjacent to implant showed increased marrow tissue at 6 weeks. Nevertheless, osteogenic structure was not observed remarkably. In a 12 weeks opinion, bone tissue composed of osseointegration along implant interface showed significantly decreased marrow tissue containing central vessels unlike a 6 weeks opinion and matured compact bone whose osteogenic structure is well formed. BIC were 42.4%, 32.0% and 34.9%, respectively in 6 weeks and there was no statistically significant difference among groups(p<0.05). In 12 weeks, BIC were 58.8%, 61.9% and 57.5%, respectively and there was no statistically significant difference among groups(p<0.05). It is considered that all 3 implant systems are suitable for immediate implant placement.
Sujets)
Animaux , Chiens , Os et tissu osseux , Moelle osseuse , Inflammation , Ostéo-intégration , DentRésumé
Objective:To study the effects of the modified sandblasting surface treatment on the bone implant interfacial shear strength of titanium dental implant.Methods:Titanium implants with smooth surface or modified sandblasted surface were inserted into femoral medialis condyli of dogs at random.The samples of implant with surrounding bone tissue were prepared in blockes and the shear strength of the interface was measured with Instron electronic pull out tester 2,4 and 12 weeks after operation. The modified sandblasted surface of the implant was observed with SEM and X ray spectroscopy 12 weeks after operation.Results:2 and 12 weeks after implantation the shear strength(MPa) between bone tissue and implants with modified sandblasted surface was 4.28?0.88 and 7.54?0.34 respectively,that between bone tissue and implants with smooth surface 0.09?0.08 and 1.43?0.46 respectively.SEM and X ray spectroscopy observation revealed that the most parts of the sandblasted surface of the implants were covered by bone tissue and bone matrix deposited into the pores created by the acid etching.Conclusion:The rough surface of titanium dental implant created by the modified sandblasting surface treatment can enhance the shear strength between bone tissue and implant.