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1.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(5): 931-937, 2020 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-33047732

RESUMO

OBJECTIVE: To study the effect of bioactive glass (BG) on the dentin bond strength and the microleakage of hybrid layer. METHODS: In the study, 30 dentin planes were prepared from the third molars with no caries and equally assigned to the control group, BG group, and sodium trimetaphosphate (STMP)-polyacrylic acid (PAA)-BG group (S-P-BG group), randomly. After etched with 35% phosphoric acid, the dentin planes of BG group were pretreated with 0.5 g/L BG, and the dentin planes of S-P-BG group were pretreated with 5% STMP, 5% PAA and 0.5 g/L BG. No additional pretreatment was done to the dentin planes of control group. Then the dentin planes were bonded using 3M Single Bond 2 adhesive to 3M Z350XT composite resin, and cut into 0.9 mm×0.9 mm column samples, which were stored at 37 ℃ artificial saliva (AS). After 24 hours, 1 month, and 3 months, the microtensile bond strength test was performed. The data were analyzed using one-way ANOVA and LSD method. The morphology of the bond fracture interface was observed with scanning electron microscope. Other 27 teeth were collected and the enamel layer and roots cut off, with the pulp chamber exposed. 0.1% rhodamine B was added to the 3M Single Bond 2 adhesive, and then the adhesive was applied to complete the bonding procedures as above. The teeth were stored in 37 ℃ AS for 24 hours, 1 month, 3 months, and then 0.1% sodium fluorescein solution was placed in the chambers and stained for 1 hour. Confocal laser scanning microscopy was used to observe the interface morphology and microleakage of the hybrid layer. RESULTS: At the end of 24 hours and 1 month, there was no significant difference in the microtensile bond strength among the three groups (P>0.05). After 3 months of soaking, the S-P-BG group [(36.91±7.07) MPa] had significantly higher microtensile bond strength than the control group [(32.73±8.06) MPa] (P=0.026); For the control group and the BG group, the microtensile bond strength significantly decreased at the end of 3 months compared with 24 hours (control group: P=0.017, BG group: P=0.01); The microtensile bond strength of S-P-BG group af the end of 3 months had no significant difference in compared with 24 hours [(37.99±7.98) MPa] (P>0.05). Observation of the fracture surface at the 24 hours showed no obvious mineralization in all the three groups. After 1 and 3 months, mineral formation was observed in BG group and S-P-BG group, and no obvious collagen exposure was observed in S-P-BG group. Confocal laser scanning microscopy revealed no obvious differences in the morphology and quantity of the resin tag in the control group, BG group and S-P-BG group. At the end of 24 hours, leakage was found in all the three groups. The microleakage of the control group increased at the end of 3 months, while the microleakage of the BG and S-P-BG groups decreased. CONCLUSION: BG pretreatment of dentin bonding interface can induce mineralization at the bonding interface and reduce the microleakage of the hybrid layer; pretreating the dentin bonding interface with STMP, PAA and BG may enhance the maintaining of the dentin bonding durability.


Assuntos
Adesivos Dentinários , Cimentos de Resina , Dentina , Vidro , Resistência à Tração
2.
Shanghai Kou Qiang Yi Xue ; 29(3): 325-328, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-33043354

RESUMO

PURPOSE: To analyze the effect and long-term success rate of using glass fiber post or metal post in restoration of anterior tooth defect. METHODS: One hundred and fifty cases with anterior tooth defects were chosen after root canal therapy in our hospital. According to different material being chosen, the patients were divided into fiber post group and metal post group with 75 cases in each group. Local gingival sulcus fluid (GCF) levels and alkaline phosphatase (ALP) level in gingival sulcus liquid were measured and compared 4 weeks, 6 months, 1 year, 2 years and 3 years after restoration. Restoration integrity, edge fitness and color matching of two groups were compared after follow-up for 3 years. The data were analyzed with SPSS 19.0 software package. RESULTS: Four weeks, 6 months, and 1 year after restoration, local GCF, ALP levels significantly elevated in both groups. The fiber post group showed more significant elevated levels of GCF and ALP than the metal post group (P<0.05). After 2 and 3 years, the difference between the two groups was not significant. The gingival color matching degrees were significantly better in the glass fiber post group after 1 year compared with that in the metal post group(P<0.05). The success rate of metal post group was significantly higher than that of fiber post group 3 years after restoration(P<0.05). CONCLUSIONS: Fiber post and metal post both have satisfactory restoration result for tooth defect in anterior teeth area. However, the use of precious metal alloy post may reduce the possibility of microleakage between tooth-prosthesis surfaces.


Assuntos
Técnica para Retentor Intrarradicular , Vidro , Humanos , Metais , Tratamento do Canal Radicular
3.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(8): 1018-1019, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32912422

RESUMO

Ampoule bottle is a small glass container for liquid medicine, with a capacity of 1-20 mL. It is often used to contain all kinds of liquid medicine for injection, vaccines, etc. Medical ampoules are related to all aspects of clinical work. In the process of operation, the opened ampoule bottle is often placed directly on the operating table. There are many shortcomings and deficiencies, for example, ampoules are easily to be overturned, causing environmental pollution, residual drug pollution, medical personnel exposure damage from their sharp ends, etc. For this reason, the medical staff from Northern Jiangsu People's Hospital designed a return box for ampoule bottle placement and obained a national utility model patent. The utility model has the advantages of being simple structured, convenient, safe and clean in the use process. The box can separate the opened ampoule bottles, reduce the waste of liquid medicine and drug pollution, effectively protect the ampoule bottle and avoid the injury of the medical staff. This new device is worth popularizing in clinical work.


Assuntos
Embalagem de Medicamentos , Vidro , Humanos , Injeções
4.
Quintessence Int ; 51(10): 844-852, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32901239

RESUMO

OBJECTIVE: To evaluate the clinical performance of the fiberglass "Figaro" crowns compared to preformed metal crowns (PMCs) in pulpotomized primary molars in children. METHOD AND MATERIALS: This split-mouth controlled randomized clinical study was performed on ten childrens, aged from 4 to 6 years, who needed complete oral rehabilitation under general anesthesia and had one pair or two pairs of their primary molars requiring pulpotomy. After pulp therapy, the teeth were randomly assigned to Figaro or PMC crown groups. Modified United States Public Health Service (USPHS) criteria were used to evaluate crown retention, marginal integration, crown discoloration, secondary caries, and gingival status, at 3 and 6 months. The data were analyzed using the chi-square test with Monte Carlo (MC) correction and McNemar (McN) test at a significance level of .05. RESULTS: Ten patients (three boys, 30%; seven girls, 70%) with a mean age of 4.65 ± 0.709 years participated in this study. At 3 months follow-up, there was no significant difference between the groups, but at 6 months follow-up, Figaro crowns showed significant changes from intact crown to either chipped or large loss, whereas all PMCs were found intact (χ2 = 14.545, P[MC] = 0.000). There was also significant deterioration in Figaro crowns' color after 6 months (χ2[McN] = 8.1, P = .004). CONCLUSION: PMCs were more durable than Figaro crowns, which showed significant deterioration after the 6-month follow-up period.


Assuntos
Coroas , Dente Decíduo , Criança , Pré-Escolar , Feminino , Vidro , Humanos , Masculino , Metais , Dente Molar
5.
Bone Joint J ; 102-B(10): 1405-1411, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32993326

RESUMO

AIMS: This exploratory randomized controlled trial (RCT) aimed to determine the splint-related outcomes when using the novel biodegradable wood-composite splint (Woodcast) compared to standard synthetic fibreglass (Dynacast) for the immobilization of undisplaced upper limb fractures in children. METHODS: An exploratory RCT was performed at a tertiary paediatric referral hospital between 1 June 2018 and 30 September 2019. The intention-to-treat population consisted of 170 patients (mean age 8.42 years (SD 3.42); Woodcast (WCG), n = 84, 57 male (67.9%); Dynacast (DNG), n = 86, 58 male (67.4%)). Patients with undisplaced upper limb fractures were randomly assigned to WCG or DNG treatment groups. Primary outcome was the stress stability of the splint material, defined as absence of any deformations or fractures within the splint during study period. Secondary outcomes included patient satisfaction and medical staff opinion. Additionally, biomechanical and chemical analysis of the splint samples was carried out. RESULTS: Of the initial 170 patients, 168 (98.8%) completed at least one follow-up, and were included for analysis of the primary endpoint. Both treatment groups were well-matched regarding to age, sex, and type and localization of the fracture. Splint breakage occurred in three patients (3.6%; 95% confidence interval (CI), 0.007% to 0.102%) in the WCG and in three children (3.5%, 95% CI 0.007% to 0.09%) in the DNG (p > 0.99). The incidence of splint-related adverse events did not differ between the WCG (n = 21; 25.0%) and DNG (n = 24; 27.9%; p = 0.720). Under experimental conditions, the maximal tensile strength of Dynacast samples was higher than those deriving from Woodcast (mean 15.37 N/mm² (SD 1.37) vs 10.75 N/mm² (SD 1.20); p = 0.002). Chemical analysis revealed detection of polyisocyanate-prepolymer in Dynacast and polyester in Woodcast samples. CONCLUSION: Splint-related adverse events appear similar between WCG and DNG treatment groups during the treatment of undisplaced forearm fractures. Cite this article: Bone Joint J 2020;102-B(10):1405-1411.


Assuntos
Traumatismos do Braço/terapia , Fraturas Ósseas/terapia , Contenções , Adolescente , Criança , Pré-Escolar , Feminino , Vidro , Humanos , Imobilização , Lactente , Análise de Intenção de Tratamento , Masculino , Desenho de Prótese , Madeira
6.
Am J Dent ; 33(4): 201-205, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32794395

RESUMO

PURPOSE: To evaluate the effect of bacterial exposure on the marginal integrity of dentin-resin interfaces for composites with and without bioactive glass (BAG). METHODS: Cavity preparations of 5 mm width and 1.5 mm depth were machined into dentin disks by means of a computer controlled milling system. After applying the bonding agent, cavity preparations (n=3-5) were restored by incremental technique with experimental resin composites (50:50 BisGMA/TEGDMA: 72wt% filler) with different filler compositions: control - 67 wt% silanated strontium glass and 5wt% aerosol-silica filler and BAG - 57 wt% silanated strontium glass and 15 wt% BAG-65 wt% silica. Samples were then stored in sterile Todd-Hewitt media or co-incubated with Streptococcus mutans (UA 159), at 37°C, 5% CO2 for 1-2 weeks. For samples co-incubated with a living biofilm, a luciferase assay was performed in order to assess its viability. Surfaces were impressed before and after each storage condition and replicas examined in a scanning electron microscope. Using image analysis software (Image J), the discontinuous margins percentage (%DM) was quantitatively assessed. Data were analyzed using two-way ANOVA followed by Tukey's test (α= 0.05). RESULTS: Gap size ranged between 7-23 µm. The bacterial exposure significantly increased the %DM in both groups predominantly due to the formation of new gap regions. There was no difference between control and BAG composites regarding %DM and the biofilm viability. Bacterial exposure promoted degradation of composite restoration marginal integrity, with no difference between composites with and without BAG. CLINICAL SIGNIFICANCE: The samples incubated with living biofilm had a higher gap percentage in the margins, confirming the negative effect of cariogenic bacteria on margin degradation. The parameters defined for such synergy can help to understand the multi-factorial aspect of marginal discontinuity and therefore, predict the behavior of composite restorations subjected to the challenging oral environment.


Assuntos
Resinas Compostas , Preparo da Cavidade Dentária , Biofilmes , Adaptação Marginal Dentária , Restauração Dentária Permanente , Vidro , Microscopia Eletrônica de Varredura , Streptococcus mutans
7.
PLoS One ; 15(8): e0237726, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813737

RESUMO

In this in vitro study, spherical mesoporous bioactive glass nanoparticle (MBGN) and non-porous bioactive glass nanoparticle (BGN) were fabricated. The impact of mesopores on dentinal tubule occlusion and bioactivity was compared to examine the potential of these materials in alleviating dentine hypersensitivity (DH). MBGN, dense BGN were synthesized by sol-gel methods and characterized. Bioactivity and ion dissolution ability were analyzed. Twenty-four simulated sensitive dentin discs were prepared and randomly divided into three groups (n = 8 each); Group 1, no treatment; Group 2, Dense BGN; Group 3, MBGN. Then, four discs per group were treated with 6wt.% citric acid challenge to determine the acidic resistance. The effects on dentinal tubule occlusion were observed by FESEM. The microtensile bond strength (MTBS) was also measured. Cytotoxicity was examined using the MTT assay. According to the results, dense BGN without mesopore and MBGN with mesopore were successfully fabricated. Dense BGN and MBGN occluded the dentinal tubule before and after acid challenge. However, only MBGN formed a membrane-like layer and showed hydroxyapatite formation after soaking SBF solution. There were no significant differences in MTBS among dense BGN, MBGN (P>0.05). The cell viability was above 72% of both materials. The higher bioactivity of MBGN compared with that of dense BGN arises from the structural difference and it is anticipated to facilitate dentin remineralization by inducing hydroxyapatite deposition within the dentinal tubule.


Assuntos
Dessensibilizantes Dentinários/administração & dosagem , Sensibilidade da Dentina/terapia , Dentina/efeitos dos fármacos , Vidro/química , Nanopartículas/administração & dosagem , Dente Pré-Molar , Dentina/metabolismo , Dessensibilizantes Dentinários/química , Dessensibilizantes Dentinários/farmacocinética , Permeabilidade da Dentina/efeitos dos fármacos , Sensibilidade da Dentina/patologia , Liberação Controlada de Fármacos , Durapatita/metabolismo , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanopartículas/química , Nanopartículas/ultraestrutura , Porosidade , Propriedades de Superfície , Resistência à Tração , Remineralização Dentária/métodos , Difração de Raios X
8.
PLoS One ; 15(8): e0237612, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790731

RESUMO

Seventeen glass vessels and twenty glass beads recovered from the excavations at the ancient city of Malindi and the archaeological site of Mambrui in Kenya, east Africa were analysed using electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results show that all of the glass samples are soda-lime-silica glass. They belong to the high alumina -plant ash glass type, characterised by high alumina and relatively low calcium contents, widely distributed in eastern (10th- 16th centuries AD) and southern Africa (13th - 15th centuries AD), Central Asia (9th- 14th centuries AD) and southeast Asia (12th- 13th centuries AD), made with plant ashes and sands. This is an understudied glass type for which previous research has indicated there were three types. When compared with published research on such glasses using Zr, Ti, Ba, Cr, La, Li, Cs, Na2O, MgO and CaO we have identified at least four different compositional groups of v-Na-Al glass: Types A, B, C and D. By comparing the results with contemporary v-Na-Al glass vessels and beads from Central Asia, Africa, and southeast Asia we show that most of the Malindi and Mambrui glass share similar characteristics to the compositions of Mapungubwe Oblate and some of the Madagascar glass beads from southern Africa. They belong to Type A v-Na-Al glass which is characterised by an elevated level of Ti and Ba and a relatively high ratios of Cr/La, relatively low Zr concentrations and low ratios of Zr/Ti. Differences in Zr, Li, MgO and Na2O concentrations in Type A glass indicates that there are subgroups which might derive from different glass workshop(s) specialising in Type A v-Na-Al glass production. Comparison with the chemical compositions of glass from Ghazni, Afghanistan and Termez, Uzbekistan, and by using lead isotope analysis, we suggest v-Na-Al glass was manufactured in Central Asia and possibly worked into vessels and beads there.


Assuntos
Compostos de Cálcio/química , Vidro/química , Óxidos/química , Plantas/química , Dióxido de Silício/química , Hidróxido de Sódio/química , Oligoelementos/análise , Oligoelementos/história , África Oriental , Óxido de Alumínio , Arqueologia , História do Século XV , História do Século XVI , Oceano Índico , Marcação por Isótopo/métodos , Quênia , Espectrometria de Massas
9.
Niger J Clin Pract ; 23(7): 950-956, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620724

RESUMO

Background: During post restoration, different root structures require several types of posts to increase duration of their clinical use. Several materials have been investigated to enhance their quality and optimize their length according to the available root canal. Aims: The aim of this study was to determine the effect of zirconia, fiber, and ceromer posts with 3- and 6-mm post sizes on the bonding strength of them to root canal dentinal wall with the means of pull-out bond strength test. Methods: Forty-eight single-rooted mandibular human premolar teeth were collected and prepared for this in vitro study. With resin cement, 3- and 6-mm study posts including zirconia, fiber, and ceromer were luted to prepare teeth. For the retention testing, the pull-out force was applied to each specimen parallel to longitudinal axis of both the post and tooth. Results: Both type of materials and size of posts changed the value of bonding strength. In all the post types, 6-mm ones performed better. Overall, the best bonding strength was obtained with fiber posts and the better bonding strength was obtained with zirconia; however, ceromer provided the least bonding strength. Conclusion: Current experiments supported that 6-mm post size can increase the bonding between root canal dentin and studied posts. When considering post materials, fiber provided the best bonding strength in current laboratory setup. Second, zirconia had meaningfully acceptable bonding strength; however, the bonding strength of ceromer posts was not favorable. Further studies optimizing post fabrication techniques of root materials may increase the bonding strength of posts to human dentin to an acceptable clinical degree.


Assuntos
Colagem Dentária , Cavidade Pulpar , Dentina , Técnica para Retentor Intrarradicular , Cimentos de Resina/química , Tratamento do Canal Radicular/métodos , Raiz Dentária/cirurgia , Cerâmica , Resinas Compostas , Vidro/química , Humanos , Teste de Materiais , Zircônio
10.
Phys Eng Sci Med ; 43(3): 765-779, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32662037

RESUMO

The COVID-19 pandemic in 2020 has led to preparations within our hospital for an expected surge of patients. This included developing a technique to perform mobile chest X-ray imaging through glass, allowing the X-ray unit to remain outside of the patient's room, effectively reducing the cleaning time associated with disinfecting equipment. The technique also reduced the infection risk of radiographers. We assessed the attenuation of different types of glass in the hospital and the technique parameters required to account for the glass filtration and additional source to image distance (SID). Radiation measurements were undertaken in a simulated set-up to determine the appropriate position for staff inside and outside the room to ensure occupational doses were kept as low as reasonably achievable. Image quality was scored and technical parameter information collated. The alternative to imaging through glass is the standard portable chest X-ray within the room. The radiation safety requirements for this standard technique were also assessed. Image quality was found to be acceptable or borderline in 90% of the images taken through glass and the average patient dose was 0.02 millisieverts (mSv) per image. The majority (67%) of images were acquired at 110 kV, with an average 5.5 mAs and with SID ranging from 180 to 300 cm. With staff positioned at greater than 1 m from the patient and at more than 1 m laterally from the tube head outside the room to minimise scatter exposure, air kerma values did not exceed 0.5 microgray (µGy) per image. This method has been implemented successfully.


Assuntos
Infecções por Coronavirus , Controle de Infecções , Pandemias , Pneumonia Viral , Radiografia Torácica , Betacoronavirus , Infecções por Coronavirus/diagnóstico por imagem , Infecções por Coronavirus/prevenção & controle , Vidro , Humanos , Controle de Infecções/instrumentação , Controle de Infecções/métodos , Controle de Infecções/normas , Saúde do Trabalhador/normas , Pandemias/prevenção & controle , Pneumonia Viral/diagnóstico por imagem , Pneumonia Viral/prevenção & controle , Radiografia Torácica/instrumentação , Radiografia Torácica/métodos , Radiografia Torácica/normas , Serviço Hospitalar de Radiologia/organização & administração , Serviço Hospitalar de Radiologia/normas
11.
PLoS One ; 15(7): e0227395, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32628681

RESUMO

The FluidFM enables the immobilization of single cells on a hollow cantilever using relative underpressure. In this study, we systematically optimize versatile measurement parameters (setpoint, z-speed, z-length, pause time, and relative underpressure) to improve the quality of force-distance curves recorded with a FluidFM. Using single bacterial cells (here the gram negative seawater bacterium Paracoccus seriniphilus and the gram positive bacterium Lactococcus lactis), we show that Single Cell Force Spectroscopy experiments with the FluidFM lead to comparable results to a conventional Single Cell Force Spectroscopy approach using polydopamine for chemical fixation of a bacterial cell on a tipless cantilever. Even for the bacterium Lactococcus lactis, which is difficult to immobilze chemically (like seen in an earlier study), immobilization and the measurement of force-distance curves are possible by using the FluidFM technology.


Assuntos
Aderência Bacteriana , Lactococcus lactis/fisiologia , Microscopia de Força Atômica/métodos , Paracoccus/fisiologia , Células Imobilizadas/fisiologia , Vidro/química , Indóis/química , Polímeros/química , Água do Mar/microbiologia , Análise de Célula Única , Propriedades de Superfície , Titânio/química
12.
J Adhes Dent ; 22(4): 353-363, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32666061

RESUMO

PURPOSE: To evaluate the influence of type and viscosity of composite resins used for root reinforcement in the adhesion of glass-fiber posts to flared root canals. MATERIALS AND METHODS: The crowns of 78 uniradicular permanent teeth were removed and the teeth were endodontically treated. After one week, the roots were prepared for root reinforcement and randomly divided into 6 groups (n = 13): positive control group ([PCG] the root canals were not enlarged), negative control group ([NCG] root canals were enlarged, no reinforcement), and in the remaining 4 groups, root canals were enlarged to receive root reinforcement according to a combination of the factors composite resin type (bulk-fill or conventional) and viscosity (flowable or regular). After fiber post cementation, six slices were obtained from each root (2 each from the cervical, middle, and apical thirds). For each group, 7 teeth underwent push-out bond strength testing, and 6 teeth were evaluated for nanoleakage and Vickers microhardness. Bond strength and nanoleakage data were submitted to two-way ANOVA and Tukey's test (α = 0.05), and microhardness data to one-way ANOVA and Tukey's test (α = 0.05). RESULTS: The root reinforcement groups with regular and flowable bulk-fill composite resins showed statistically superior adhesion results (higher bond strength and less nanoleakage) compared to the negative control in all root regions. Microhardness values were higher in the cervical third followed by the middle third. CONCLUSION: Regular or flowable bulk-fill composite resins should be chosen for root reinforcement of flared root canals prior to fiber post cementation.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Resinas Compostas , Cavidade Pulpar , Análise do Estresse Dentário , Vidro , Teste de Materiais , Cimentos de Resina
13.
J Contemp Dent Pract ; 21(5): 515-520, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32690833

RESUMO

AIM: To evaluate in vitro effect of apical root canal perforation size on push-out bond strength of glass fiber dowels cemented to sound or perforated root canals using two different adhesive systems. MATERIALS AND METHODS: A total of 120 human-extracted intact upper central incisors were selected. Teeth were sectioned 3 mm coronal to cement enamel junction, and the remaining root received endodontic root canal therapy. The roots were divided into two experimental groups according to the root condition: either sound (n = 40) or apically perforated (n = 80). Dowel spaces were prepared for all specimens to a depth of 10 mm. Roots were restored with glass fiber dowels. The experimental group was further subdivided into four subgroups (n = 20) according to the adhesive system used and apical perforation size: group I, perforated root 2 mm apically, dowel cemented using total-etch adhesive cement; group II, perforated root 2 mm apically, dowel cemented using self-etch adhesive cement; group III, perforated root 4 mm apically, dowel cemented using total-etch adhesive cement; and group IV, perforated root 4 mm apically, dowel cemented using self-etch adhesive cement. The control group, sound root, was divided into two subgroups: group I, sound root, dowel cemented using total-etch adhesive cement, and group II, sound root, dowel cemented using self-etch or total-etch adhesive cement. Each root was then cut horizontally, and root segments were prepared to be tested. The bond strength between dowel and dentin was measured with universal testing machine using a push-out test. The two-way analysis of variance (ANOVA) was used to analyze the data and post hoc Tukey's test (α = 0.05). RESULTS: Root canal perforation and the type of adhesive system used resulted in significant differences in push-out bond strength (p < 0.05). Regardless of root canal perforation size, glass fiber dowels in normal root canals had significantly higher mean bond strength values (9.2 ± 1.4 MPa) compared with perforated root canals (6.1 ± 1.4 MPa). Also, self-etch protocol had significantly higher mean bond strength values (9.1 ± 1.3 MPa) compared with total-etch protocol (6.2 ± 2.1 MPa). CONCLUSION: The apical root perforation size caused a direct effect on the bond strength of the glass fiber dowels cemented to dentin by reducing the bond strength values to the root dentin regardless of the adhesive system used. CLINICAL SIGNIFICANCE: Prior to perforation repair, dentist or endodontist should evaluate the perforation size to predict the treatment outcome.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Cavidade Pulpar , Dentina , Vidro , Humanos , Teste de Materiais , Cimentos de Resina , Tratamento do Canal Radicular
14.
Waste Manag ; 114: 53-61, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32659687

RESUMO

Spent liquid crystal displays (LCDs) are a secondary source of precious/strategic metals, including indium (In). The present study involved optimizing the solubilization of this strategic element from samples of indium tin oxide (ITO) glass prepared from LCD screens of computer monitors and laptop screens. The influence of operating conditions on In solubilization, as well as optimum conditions for sulfuric acid leaching were defined by a Box-Behnken-type experimental design methodology. Optimum operating conditions include a leaching step for 30 min at a temperature of 70 °C in the presence of 0.4 N H2SO4 and a pulp density of 50% (w/v). Under these conditions, the quadratic model established to predict the solubilization of In from ITO glass samples provided an In solubilization efficiency of 89.7%, which was validated experimentally (99.5%). The analysis of direct operating costs and capital costs for the implementation of such a leaching process revealed that the process is conceivable for a high-capacity plant processing ~100 t/day of ITO glass.


Assuntos
Resíduo Eletrônico/análise , Cristais Líquidos , Vidro , Índio , Reciclagem
15.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(7): 461-465, 2020 Jul 09.
Artigo em Chinês | MEDLINE | ID: mdl-32634884

RESUMO

Fiber-reinforced resin composite posts (fiber posts) are used extensively for the restoration of root-treated teeth with excessive loss of coronal structure. However, the longevity of a fiber post restoration still needs to be improved because of the various confounding factors that affect bonding procedures. Operational specification for clinical use of dental intraradicular fiber post was established based on the in-depth discussions by a panel of experts from Society of Prosthodontics, Chinese Stomatological Association. This specification should be helpful in standardizing the clinical technique of fiber post placement and improving the clinical longevity of a fiber post restoration.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Cimentação , Resinas Compostas , Análise do Estresse Dentário , Vidro , Teste de Materiais , Cimentos de Resina , Raiz Dentária
16.
Emerg Infect Dis ; 26(9)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32579874

RESUMO

We spotted severe acute respiratory syndrome coronavirus 2 on polystyrene plastic, aluminum, and glass for 96 hours with and without bovine serum albumin (3 g/L). We observed a steady infectivity (<1 log10 drop) on plastic, a 3.5 log10 decrease on glass, and a 6 log10 drop on aluminum. The presence of proteins noticeably prolonged infectivity.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/transmissão , Transmissão de Doença Infecciosa , Fômites/virologia , Pneumonia Viral/transmissão , Alumínio/análise , Infecções por Coronavirus/virologia , Vidro/análise , Humanos , Pandemias , Plásticos/análise , Pneumonia Viral/virologia , Fatores de Tempo
17.
J Appl Oral Sci ; 28: e20190384, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520077

RESUMO

OBJECTIVES: This study evaluated if the use of a bioactive glass-ceramic-based gel, named Biosilicate (BS), before, after or mixed with bleaching gel, could influence the inflammation of the dental pulp tissue of rats' molars undergoing dental bleaching with hydrogen peroxide (H2O2). METHODOLOGY: The upper molars of Wistar rats (Rattus norvegicus, albinus) were divided into Ble: bleached (35% H2O2, 30-min); Ble-BS: bleached and followed by BS-based gel application (20 min); BS-Ble: BS-based gel application and then bleaching; BS/7d-Ble: BS-based gel applications for 7 days and then bleaching; Ble+BS: blend of H2O2 with BS-based gel (1:1, 30-min); and control: placebo gel. After 2 and 30 days (n=10), the rats were euthanized for histological evaluation. The Kruskal-Wallis and Dunn statistical tests were performed (P<0.05). RESULTS: At 2 days, the Ble and Ble-BS groups had significant alterations in the pulp tissue, with an area of necrosis. The groups with the application of BS-based gel before H2O2 had moderate inflammation and partial disorganization in the occlusal third of the coronary pulp and were significantly different from the Ble in the middle and cervical thirds (P<0.05). The most favorable results were observed in the Ble+BS, which was similar to the control in all thirds of the coronary pulp (P>0.05). At 30 days, the pulp tissue was organized and the bleached groups presented tertiary dentin deposition. The Ble group had the highest deposition of tertiary dentin, followed by the Ble-BS, and both were different from control (P<0.05). CONCLUSION: A single BS-based gel application beforehand or BS-based gel blended with a bleaching gel minimize the pulp damage induced by dental bleaching.


Assuntos
Polpa Dentária/efeitos dos fármacos , Vidro/química , Peróxido de Hidrogênio/química , Pulpite/prevenção & controle , Clareadores Dentários/química , Clareamento Dental/métodos , Animais , Polpa Dentária/patologia , Peróxido de Hidrogênio/efeitos adversos , Masculino , Dente Molar , Pulpite/induzido quimicamente , Pulpite/patologia , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo , Clareamento Dental/efeitos adversos , Clareadores Dentários/efeitos adversos , Resultado do Tratamento
18.
Geobiology ; 18(5): 525-543, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32542902

RESUMO

Microtextures of titanite (CaTiSiO5 ) in exceptionally preserved Archean pillow lavas have been proposed as the earliest examples of microbial ichnofossils. An origin from microbial tunneling of seafloor volcanic glass that is subsequently chloritized and the tunnels infilled by titanite has been argued to record the activities of subseafloor microbes. We investigate the evidence in pillow lavas of the 3.35 Ga Euro Basalt from the Pilbara Craton, Western Australia, to evaluate the biogenicity of the microtextures. We employ a combination of light microscopy and chlorite mineral chemical analysis by EPMA (electron probe micro-analysis) to document the environment of formation and analyze their ultrastructure using FIB-TEM (focussed ion beam combined with transmission electron microscopy) to investigate their mode of growth. Petrographic study of the original and re-collected material identified an expanded range of titanite morphotypes along with early anatase growth forming chains and aggregates of coalesced crystallites in a sub-greenschist facies assemblage. High-sensitivity mapping of FIB lamellae cut across the microtextures confirm that they are discontinuous chains of coalesced crystallites that are highly variable in cross section and contain abundant chlorite inclusions, excluding an origin from the mineralization of previously hollow microtunnels. Comparison of chlorite mineral compositions to DSDP/IODP data reveals that the Euro Basalt chlorites are similar to recent seafloor chlorites. We advance an abiotic origin for the Euro Basalt microtextures formed by spontaneous nucleation and growth of titanite and/anatase during seafloor-hydrothermal metamorphism. Our findings reveal that the Euro Basalt microtextures are not comparable to microbial ichnofossils from the recent oceanic crust, and we question the evidence for life in these Archean lavas. The metamorphic reactions that give rise to the growth of the Euro Basalt microtextures could be commonplace in Archean pillow lavas and need to be excluded when seeking traces of life in the subseafloor on the early Earth.


Assuntos
Planeta Terra , Austrália , Vidro , Minerais , Austrália Ocidental
19.
Oral Health Prev Dent ; 18(1): 529-536, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32515424

RESUMO

PURPOSE: To evaluate the effect of pre-treatment air abrasion of surfaces using bioactive glass 45S5 on the progression of erosion in bovine enamel induced by a common soft drink. MATERIALS AND METHODS: Twelve intact bovine incisors were selected and 24 enamel samples were prepared and randomly assigned to two groups (n = 12): 1. control group, no anti-erosive treatment; 2. experimental group: samples were air abraded with bioglass 45S5 before the erosive challenge. The enamel samples were submitted to erosive cycling using a common soft drink. Enamel surface loss was evaluated using optical profilometry; surface microhardness and roughness changes were determined using Vickers method and Vertical Scanning Interferometry, respectively. In addition, SEM observations and EDS analysis were performed to detect any alterations in surface morphology and mineral content. The data were statistically analysed using one-way ANOVA and Tukey's post-hoc test at a significance level of α = 0.05. RESULTS: The experimental group exhibited less (18.7%) surface loss than did the control group (p < 0.05), while also presenting a statistically significantly smaller decrease in surface microhardness compared to the control group after erosive cycling (p < 0.05). However, neither group showed a statistically significant change in surface roughness (p > 0.05). After the treatments, changes in surface morphology and mineral content of enamel were observed. CONCLUSIONS: Surface pre-treatment using air abrasion bioglass 45S5 may help prevent enamel erosion induced by excessive consumption of soft drinks. Further clinical trials are needed to confirm the effectiveness of this method and its clinical significance.


Assuntos
Erosão Dentária , Abrasão Dental por Ar , Animais , Bovinos , Cerâmica , Esmalte Dentário , Vidro , Propriedades de Superfície
20.
World Neurosurg ; 141: 402-405, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32561491

RESUMO

BACKGROUND: Nonmissile penetrating injuries to the craniocervical junction caused by a glass fragment are rare, and a standard management strategy has not been established. CASE DESCRIPTION: A 75-year-old Japanese man was brought into our emergency department after receiving a left retroauricular stab wound by broken glass fragments. After spinal immobilization, a computed tomography (CT) scan revealed glass fragments penetrating at the right craniocervical junction to the interatlantooccipital subarachnoid space. CT angiography showed that both vertebral arteries were not injured. Magnetic resonance imaging demonstrated that the glass fragments did not penetrate the cervical cord or medulla oblongata. These glass fragments were removed via a midline incision from the external occipital protuberance to the C7 and with laminectomy without suboccipital craniectomy. Five of the glass fragments were found and removed in total. The dural defect was patched with a free fascia autograft. His postoperative course was uneventful. Postoperative CT angiography showed that both vertebral arteries were intact and the glass fragments had been removed completely. CONCLUSIONS: CT graphical diagnosis is useful for the management of penetrating craniocervical junction trauma, and it should be considered in the evaluation of patients who have suffered craniocervical penetrating injury even in the absence of major wounds or bleeding. Spinal immobilization of patients with craniocervical penetrating injuries is crucial to avoid not only secondary neurologic damage but also secondary critical vascular damage. Incomplete or inadequate assessment of craniocervical stab wounds results in unexpected hazards that are preventable.


Assuntos
Articulação Atlantoccipital/lesões , Infecções por Coronavirus , Vidro , Pandemias , Pneumonia Viral , Espaço Subaracnóideo/lesões , Traumatismos do Sistema Nervoso/complicações , Traumatismos do Sistema Nervoso/cirurgia , Idoso , Articulação Atlantoccipital/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética , Masculino , Espaço Subaracnóideo/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Traumatismos do Sistema Nervoso/diagnóstico por imagem , Ferimentos Penetrantes/complicações , Ferimentos Penetrantes/cirurgia , Ferimentos Perfurantes/terapia
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