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1.
J Esthet Restor Dent ; 36(3): 484-493, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37933985

RESUMO

OBJECTIVE: The effects of four toothpastes on the color stability of in-office bleached tooth specimens were determined. MATERIALS AND METHODS: We evaluated an experimental toothpaste (EXP) and three commercially available toothpastes: Colgate Optic White (OPW), Aquafresh White & Protect (AWP), and Crest 3D White (CDW). OPW, AWP, and CDW contained inorganic abrasives, whereas EXP and AWP contained sodium polyphosphate. Forty-eight randomly selected human-extracted maxillary central incisors were bleached and brushed twice daily over 30 days. We analyzed the final color difference (ΔE*ab, ΔE00 , ΔWID ), arithmetic average surface roughness (Ra) of the enamel measured on days 0 and 30, and scanning electron microscopy images of enamel surfaces and toothpastes. ΔE*ab, ΔE00 , ΔWID , and Ra were analyzed using one-way analysis of variance and Tukey's test (α = 0.05). RESULTS: ΔE*ab and ΔE00 values were significantly lower after toothbrushing with EXP, OPW, and CDW than with AWP. OPW induced the greatest positive ΔWID . Ra was significantly increased by OPW and CDW, but slightly increased by AWP, with cube-like particles, and EXP, with no particle-like structures. CONCLUSIONS: Only EXP stabilized the color of bleached teeth without increasing the enamel surface roughness. Sodium polyphosphate with approximately 10 phosphate groups was effective at removing stains. CLINICAL SIGNIFICANCE: The effect of toothpaste on the color stability of bleached teeth depends on the constituting abrasives and chemical components. Polyphosphoric acid has different stain-removal effects depending on its degree of polymerization. Additionally, although certain types of abrasives may be effective for color stability, they also increase the surface roughness of the enamel.


Assuntos
Clareamento Dental , Cremes Dentais , Humanos , Cremes Dentais/farmacologia , Cremes Dentais/análise , Cremes Dentais/química , Corantes/análise , Corantes/farmacologia , Esmalte Dentário/química , Clareamento Dental/métodos , Escovação Dentária/métodos , Polifosfatos/farmacologia , Polifosfatos/análise , Sódio/análise , Sódio/farmacologia , Cor
2.
Am J Dent ; 34(4): 179-185, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34370908

RESUMO

PURPOSE: To compare the effect of the immediate dentin sealing (IDS) and resin cement type on fracture resistance of Class II mesio-occluso-distal (MOD) zirconia inlay restorations. METHODS: 90 Class II MOD cavities on freshly extracted human mandibular third molars, prepared with a high-speed handpiece, were divided into two groups: those with IDS (CR+) and without IDS (CR-). The CEREC system was used to prepare zirconia inlays from Katana super translucent multi-layered blocks. The inlays were cemented with one of three resin cements: RelyX Unicem 2 (RU), Multilink Automix (MA), or Super-Bond (SB). These specimens were stored in water at 37°C for 24 hours and exposed to 5,000 thermal cycles. A vertical load was applied with a metal sphere (Φ 6-mm) on a material testing system, with a crosshead speed of 0.5 mm/minute, until the specimen fractured. Fracture resistance was measured for each tooth, and the fractures were categorized according to Burke's classification. Statistical analyses were conducted using two-way ANOVA and Tukey's honest significant difference tests (P< 0.05). RESULTS: No significant differences in tooth fracture resistance were identified between the CR+ and CR- groups. The SB group had a significantly higher fracture resistance compared to that of the MA group. Fracture morphology showed many mode IV fractures in all groups. IDS did not affect tooth fracture resistance, although there was a significant difference in tooth fracture resistance for different resin cement types used with Class II MOD zirconia inlay restorations. CLINICAL SIGNIFICANCE: Zirconia inlay restorations provide excellent mechanical performance, morphology, and esthetic appearance. In vitro, zirconia inlays cemented with any luting resin cement restored tooth fracture resistance to levels similar to that of intact teeth. Fracture resistance varied among the different resin cements.


Assuntos
Cimentos de Resina , Fraturas dos Dentes , Resinas Compostas , Porcelana Dentária , Análise do Estresse Dentário , Dentina , Humanos , Restaurações Intracoronárias , Teste de Materiais , Zircônio
3.
J Contemp Dent Pract ; 20(3): 395-402, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31204334

RESUMO

AIM: The purpose of this review is to address the smear layer removing the ability of root different canal irrigants including ethylenediaminetetraacetic acid (EDTA), a mixture of tetracycline, acid and detergent (MTAD), tetraclean, citric acid, Q-Mix, maleic acid, and smear clear. BACKGROUND: Smear layer is a layer which is produced during instrumentation. It contains both organic and inorganic materials. It may also contain bacteria and their byproduct considering the root canal situation. This layer may prevent the penetration of the healing material introduced to the canal to the interior of the dentinal tubules. In addition, it can affect the adaptation of sealing materials to the root canal walls. REVIEW RESULTS: The smear layer removal ability of MTAD is superior and faster than EDTA. Tetraclean is similarly composed of an acid, an antibiotic, and a detergent. The presence of doxycycline is believed to help the smear layer removal ability of these irrigants. Antibiotics such as tetracycline had similar smear layer removal ability as even citric acid. EDTA is an amino acid with a chelating ability that sequestrates metal ions. Some believed EDTA smear layer removing ability is better than MTAD, tetraclean, SmearClear, and 20% citric acid which is controversial in case of comparison between MTAD and EDTA. Phosphoric acid is efficient enough to be comparable to EDTA in removing the smear layer. Maleic acid is an organic compound with acid etching smear layer removal. Its ability seems to be similar or even better than EDTA. Citric acid as another organic acid is believed to be used as smear removing agent. HEBP is another chelating agent that can be used in combination with NaOCl; however, HEBP is a weak decalcifying agent compared to EDTA and hence cannot be applied as a mere final rinse. QMiX is a combination of CHX, EDTA, and detergent and should be used at final rinse. It is believed that QMiX is as efficient as EDTA. Smear clear is a 17% EDTA solution including an anionic and cationic (cetrimide) surfactant. The ability of QMiX is similar to EDTA. CONCLUSION: There are different canal irrigation solutions with various smear layer removal ability that some should be used as a mere final rinse and some should not. CLINICAL SIGNIFICANCE: The usage of canal irrigation solutions depends on the clinical situation and preference of the dentists. This study provides a good guide for clinician of the field.


Assuntos
Camada de Esfregaço , Cavidade Pulpar , Ácido Edético , Humanos , Microscopia Eletrônica de Varredura , Polissorbatos , Irrigantes do Canal Radicular , Hipoclorito de Sódio
4.
J Contemp Dent Pract ; 20(7): 873-877, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31597812

RESUMO

AIM: The aim of this study is to report manufacturing a consolidated pulp test system that includes thermometry, flowmetry, and pulse oximetry. BACKGROUND: The ideal method for the evaluation of pulp vitality should be objective, noninvasive, easy to use, reliable, and painless. Currently, the most commonly used tests (such as electricity, heat, and cold tests) depend on patients' sensibility and are highly subjective. They only measure a neural response and do not indicate the actual biologic status of the pulp. It has, therefore, been suggested that vitality tests such as flowmetry, pulse oximetry, thermometry, and photoplethysmography be used. Some research has been done on these systems; however, their high costs and space need to maintain all of them that have been obstacles to their use. TECHNIQUE: This report describes designing and manufacturing a novel system for evaluating pulp vitality involving the use of three methods (flowmetry, pulse oximetry, and thermometry) combined in a single small system using only two probes. CONCLUSION: The consolidated pulp tests system may be accurate in determining the pulp vitality. However, after clinical use, some changes may be necessary for improvement of the system.


Assuntos
Teste da Polpa Dentária , Oximetria , Polpa Dentária , Temperatura Alta , Humanos , Reologia
5.
J Contemp Dent Pract ; 19(12): 1469-1473, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30713175

RESUMO

AIM: Teeth extraction is an important problem in elder patients. Although some of these teeth have been endodontically treated, many of them may be subjected to extraction. The reasons for extraction are important for prevention planning in further patients. The aim of this study was to assess the prevalence and important reasons for extraction of endodontically treated teeth in adult Nigerians. MATERIALS AND METHODS: This study involved a retrospective examination of 2,000 case files in the archives of the University of Nigeria Teaching Hospital. Out of the 2,000 case files, 650 concerned endodontically treated teeth. RESULTS: The prevalence of extractions in the population was 21.5%. This was more often in the mandible (67.9%) than in the maxilla (32.1%). In both jaws, more molars were extracted (57.1%), followed by premolars (27.1%) and anterior teeth (15.7%). Extractions occurred 57.1% of times in females. However, the rate of extraction decreased with age but peaked in the 51-60 year age band. CONCLUSION: The association between age and extraction was proven. Caries, vertical root fracture and endodontic reasons accounted for the commonest cause of extraction in the mandible; while in the maxilla, endodontic reasons and cusp fracture caused extractions most often. CLINICAL SIGNIFICANCE: The reasons for extraction of endodontically treated teeth are different between maxilla and mandible.


Assuntos
Extração Dentária/estatística & dados numéricos , Dente não Vital/cirurgia , Fatores Etários , Cárie Dentária/epidemiologia , Doenças da Polpa Dentária/epidemiologia , Feminino , Humanos , Masculino , Mandíbula , Maxila , Pessoa de Meia-Idade , Nigéria/epidemiologia , Prevalência , Estudos Retrospectivos , Fatores Sexuais , Fraturas dos Dentes/epidemiologia , Raiz Dentária
6.
Acta Biomater ; 171: 193-201, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37669711

RESUMO

A considerable material discontinuity between the enamel and dentin might jeopardize the tooth's mechanical durability over time without the attenuation of the dentin-enamel junction (DEJ). However, the critical loading transmission mechanism at the DEJ remains understudied. This study aimed to define the extent and effective width of the DEJ, along with its mechanical competence. The presence of DEJ interphase layer was identified using a motif analysis based on the ion beam-transmission electron microscopy coupled with nanoindentation modulus mapping. For each region, nanoindentation load-displacement curves were recorded and mathematically analyzed using an appropriate viscoelastic constitutive model. The time-course of indenter penetration (creep) behavior of the tooth tissues can be mathematically approximated by the Kelvin-Voigt model in series, which determined the visco-contribution to the overall mechanical responses. Therefore, the elastic-plastic contribution can be distinguished from the overall mechanical responses of the tooth after subtracting the visco-contributions. During the loading period, the enamel behavior was dominated by elastic-plastic responses, while both the dentin and DEJ showed pronounced viscoelastic responses. The instantaneous modulus of the DEJ, which was measured by eliminating viscoelastic behavior from the raw load-displacement curve, was almost double that of the dentin. The DEJ was stiffer than the dentin, but it exhibited large viscoelastic motion even at the initial loading stage. This study revealed that the load attenuation competence of the DEJ, which involves extra energy expenditure, is mainly associated with its viscoelasticity. The mathematical analysis proposed here, performed on the nanoindentation creep behavior, could potentially augment the existing knowledge on hard-tissue biomechanics. STATEMENT OF SIGNIFICANCE: In this study, we undertake a rigorous mechanical characterization of the dentin-enamel junction (DEJ) using an advanced nanoindentation technique coupled with a pertinent viscoelastic constitutive model. Our approach unveils the substantial viscoelastic contribution of the DEJ during the initial indentation loading phase and offers an elaborate delineation of the DEJ interphase layer through sophisticated image analysis. These insights significantly augment our understanding of tooth durability. Importantly, our innovative mathematical analysis of creep behavior introduces a novel approach with profound implications for future research in the expansive field of hard-tissue biomechanics. The pioneering methodologies and findings presented in this work hold substantial potential to invigorate progress in biomaterials research and fuel further explorations into the functionality of biological tissues.


Assuntos
Dentina , Dente , Dentina/fisiologia , Estresse Mecânico , Fenômenos Biomecânicos , Esmalte Dentário
7.
J Clin Pediatr Dent ; 37(2): 183-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23534327

RESUMO

OBJECTIVE: The purpose of this study was to investigate the adhesion of glass ionomer cements to dentin and the effect of pretreatment using Carisolv. STUDY DESIGN: Forty extracted permanent teeth with caries were used for this study. All lesions were removed using the Carisolv system and teeth were divided into eight groups. Groups 1 to 4 were filled with three types of conventional glass ionomer cements and a resin modified glass ionomer cement. Group 8 was restored with composite resin. In the remaining three groups (Groups 5 to 7), several pretreatment procedures, including EDTA and dentin primer application and a combination of these, were performed before restoring with resin modified glass ionomer cement. All restorations were thermocycled, and microleakage tests were performed on all teeth. RESULTS: There were no statistical differences among Groups 1, 2 and 3 or between Groups 4 and 8. However Groups 1 to 3 had higher microleakage levels than Groups 4 and 8. Groups 5 to 7 showed similar leakage levels as Group 4. CONCLUSION: Pretreatment with EDTA or dentin primer did not improve bonding ability. Combination of caries removal using Carisolv and a resin modified glass ionomer cement restoration without pretreatment seems to be an acceptable method for caries treatment.


Assuntos
Colagem Dentária , Preparo da Cavidade Dentária/métodos , Infiltração Dentária/prevenção & controle , Restauração Dentária Permanente/métodos , Adesivos Dentinários/química , Cimentos de Ionômeros de Vidro/química , Ácido Glutâmico , Leucina , Lisina , Adesividade , Dente Pré-Molar , Cárie Dentária/terapia , Corrosão Dentária , Dentina/efeitos dos fármacos , Ácido Edético , Ácido Glutâmico/farmacologia , Humanos , Leucina/farmacologia , Lisina/farmacologia , Dente Molar , Camada de Esfregaço , Colo do Dente/patologia , Molhabilidade
8.
Cell Tissue Res ; 346(1): 99-109, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21922246

RESUMO

The presence of macrophages in dental pulp is well known. However, whether these macrophages proliferate and differentiate in the dental pulp in situ, or whether they constantly migrate from the blood stream into the dental pulp remains unknown. We have examined and compared the development of dental pulp macrophages in an organ culture system with in vivo tooth organs to clarify the developmental mechanism of these macrophages. The first mandibular molar tooth organs from ICR mice aged between 16 days of gestation (E16) to 5 days postnatally were used for in vivo experiments. Those from E16 were cultured for up to 14 days with or without 10% fetal bovine serum. Dental pulp tissues were analyzed with immunohistochemistry to detect the macrophages and with reverse transcription and the polymerase chain reaction (RT-PCR) for the detection of factors related to macrophage development. The growth curves for the in vivo and in vitro cultured cells revealed similar numbers of F4/80-positive macrophages in the dental pulp. RT-PCR analysis indicated the constant expression of myeloid colony-stimulating factor (M-CSF) in both in-vivo- and in-vitro-cultured dental pulp tissues. Anti-M-CSF antibodies significantly inhibited the increase in the number of macrophages in the dental pulp. These results suggest that (1) most of the dental pulp macrophages proliferate and differentiate in the dental pulp without a supply of precursor cells from the blood stream, (2) M-CSF might be a candidate molecule for dental pulp macrophage development, and (3) serum factors might not directly affect the development of macrophages.


Assuntos
Diferenciação Celular/fisiologia , Proliferação de Células , Macrófagos/citologia , Dente Molar/citologia , Animais , Bovinos , Polpa Dentária , Feminino , Regulação da Expressão Gênica/fisiologia , Fator Estimulador de Colônias de Macrófagos/biossíntese , Macrófagos/metabolismo , Mandíbula/citologia , Mandíbula/embriologia , Mandíbula/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Dente Molar/embriologia , Dente Molar/metabolismo , Técnicas de Cultura de Tecidos
9.
Medicines (Basel) ; 8(6)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204458

RESUMO

Background: Japanese herbal medicine, called Kampo medicine, and acupuncture are mainly used in Japanese traditional medicine. In this experiment, the analgesic effect of Yokukansan (YKS) alone and a combination of YKS and electroacupuncture (EA) on inflammatory pain induced by formalin injection were examined. Methods: Animals were divided into four groups: a control group, formalin injection group (formalin), YKS-treated formalin group (YKS), and YKS- and EA-treated formalin group (YKS + EA). The duration of pain-related behaviors and extracellular signal-regulated protein kinase (ERK) activation in the spinal cord after formalin injection in the right hind paw were determined. Results: The duration of pain-related behaviors was dramatically prolonged in the late phase (10-60 min) in the formalin group. The YKS treatment tended to reduce (p = 0.08), whereas YKS + EA significantly suppressed the pain-related behaviors (p < 0.01). Immunohistochemical and Western blot analyses revealed that the number of phosphorylated ERK1/2 (pERK1/2)-positive cells and the pERK expression level, which were increased by formalin injection, were significantly inhibited by YKS (p < 0.05) and YKS + EA (p < 0.01). Conclusions: The YKS + EA combination therapy elicited an analgesic effect on formalin-induced acute inflammatory pain.

10.
Dent Mater J ; 29(3): 316-23, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20484831

RESUMO

The aim of the present study was to evaluate the bonding durability of resin-based luting cement to partially stabilized tetragonal zirconia (Y-TZP) achieved by combination treatment of tribochemical (TBC) treatment and two different phosphate acid ester monomers. Two phosphate acid ester monomers (EP: Epricord opaque primer, AZ: AZ primer) were applied to each surface modification followed by application of resin-based luting cement (Rely-X ARC). Bonding specimens were placed in deionized water at 37 degrees C and stored for 24 h. The other groups were subjected to 30,000 cycles of a thermal stress for the durability test. Shear bond tests were done using a universal testing machine at 1 mm/min. Shear bond strengths of combination treatments using EP and AZ on TBC treatment after thermal stress showed no significant difference (p>0.05) compared with those of storage after 24 h. Combination treatment using phosphoric acid ester monomer could achieve a durable bond.


Assuntos
Colagem Dentária , Corrosão Dentária/métodos , Porcelana Dentária , Organofosfatos , Cimentos de Resina , Bis-Fenol A-Glicidil Metacrilato , Resinas Compostas , Análise do Estresse Dentário , Fricção , Teste de Materiais , Metacrilatos , Ácido Fosfonoacéticos/análogos & derivados , Polietilenoglicóis , Ácidos Polimetacrílicos , Resistência ao Cisalhamento , Ítrio , Zircônio
11.
Dent Mater J ; 39(6): 1000-1008, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-32684610

RESUMO

The effect of etching for 90 s with low concentrations (0.5, 1.0, 2.0, 3.0, 3.5, and 4.0%) of hydrofluoric acid (HF) on the adhesiveness of computer-aided design/computer-aided manufacturing (CAD/CAM) resin blocks [CERASMART (CS), SHOFU BLOCK HC (HC), KATANA AVENCIA Block(KA), and VITA ENAMIC (EN)] was investigated. Energy dispersive spectroscopy revealed that the silicon content of HC, KA, and EN groups remained almost constant with HF etching of ≤4%. HF etching increased the surface roughness of all blocks. The HF concentration resulting in the highest shear bond strength in each group was as follows: CS (2.0%), HC (3.0%), KA (3.5%) and EN (0.5%). Scanning electron microscopy revealed that the bonding interface of etched surfaces differed significantly from that of airborne-particle abrasion surfaces. Thus, low concentration HF etching is effective for surface treatment of CAD/CAM resin blocks. The etching effect and optimum HF concentration differ with the block composition and structure.


Assuntos
Colagem Dentária , Ácido Fluorídrico , Cerâmica , Desenho Assistido por Computador , Porcelana Dentária , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Propriedades de Superfície
12.
Nutrients ; 12(1)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963184

RESUMO

Ginkgo seed coat is rarely used and is typically discarded, due to its offensive odor and its toxicity. Ginkgo vinegar is a fermented product of ginkgo seed coat, and fermentation removes the bad smell and most of the toxicity. Thus, ginkgo vinegar contains very low concentrations of toxic components. The present study examined the anti-obesity effect of ginkgo vinegar in mice fed a high-fat diet and its inhibition of adipogenesis in 3T3-L1 cells. Ginkgo vinegar suppressed high-fat diet-induced body weight gain and reduced the size of fat cells in mice. Ginkgo vinegar suppressed the expression of C/EBPδ and PPARγ, key proteins in adipogenesis, and inhibited lipid accumulation in 3T3-L1 cells that were induced to become adipocytes. These results suggested that ginkgo vinegar inhibited adipocyte differentiation. On the other hand, a corresponding concentration of acetic acid had significantly less effect on lipid accumulation and virtually no effect on adipogenic gene expression. These results suggested that, similar to Ginkgo biloba extract, ginkgo vinegar might prevent and improve adiposity. Therefore, ginkgo seed coat could be a useful material for medicinal ingredients.


Assuntos
Ácido Acético/farmacologia , Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Fármacos Antiobesidade/farmacologia , Dieta Hiperlipídica , Ginkgo biloba , Obesidade/prevenção & controle , Extratos Vegetais/farmacologia , Sementes , Células 3T3 , Ácido Acético/isolamento & purificação , Adipócitos/metabolismo , Adipogenia/genética , Animais , Fármacos Antiobesidade/isolamento & purificação , Proteína delta de Ligação ao Facilitador CCAAT/genética , Proteína delta de Ligação ao Facilitador CCAAT/metabolismo , Modelos Animais de Doenças , Fermentação , Ginkgo biloba/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/genética , Obesidade/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Extratos Vegetais/isolamento & purificação , Sementes/química , Redução de Peso/efeitos dos fármacos
13.
Dent Mater J ; 28(5): 552-7, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19822985

RESUMO

The purpose of this in vitro investigation was to study the effects on bond strength to primed human enamel stemming from opacity and polymerization inhibition by oxygen due to two coating resins. The coating resins and primers used were White Coat and an experimental material, SIR. The bond strengths on fine-ground enamel were evaluated for three shades of each of these coating resins after 24-hour storage in water. In addition, their degrees of opacity and oxygen inhibition depths were measured. The mild self-etch primer solutions produced very shallow but distinct etching patterns for micromechanical retention of the coating resin. Significant linear relationships between bond strength on the one hand and opacity and oxygen inhibition depth on the other were found for the three shades of each coating resin. Generally, the bond strength mediated on enamel is sufficiently high when these resins are combined with their proprietary adhesives. Therefore, the decrease in bond strength with increasing opacity of the coating resin shades has to be taken into account during application and light-curing.


Assuntos
Resinas Compostas/química , Esmalte Dentário/química , Corrosão Dentária/métodos , Facetas Dentárias , Cura Luminosa de Adesivos Dentários/métodos , Materiais Revestidos Biocompatíveis/química , Materiais Dentários/química , Falha de Restauração Dentária , Análise do Estresse Dentário , Humanos , Incisivo , Maxila , Oxigênio/química , Resistência ao Cisalhamento , Propriedades de Superfície
14.
Dent Mater J ; 28(3): 338-43, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19662733

RESUMO

The purpose of this in vitro investigation was to study the effects of coffee and tea immersion on surface discoloration of one commercial temporary resin coating material, White Coat (WHC; Kuraray Medical Inc., Tokyo, Japan), and an experimental one, SI-R20209 (SIR; Shofu Inc., Kyoto, Japan). Disk-shaped specimens were prepared, their colors were determined at baseline, and after immersion in water (control), tea and coffee solutions for 24, 48, and 72 hours. Very little discoloration was found with the water-stored specimens. Staining response was most pronounced after coffee immersion for White Coat and after tea immersion for the experimental material, exceeding the clinically acceptable discoloration threshold value of deltaE=3.3. However, most of the resin shades tested are likely to be sufficiently safe against heavy discoloration when used for short-term restoration only.


Assuntos
Café , Resinas Compostas/química , Materiais Dentários/química , Chá , Cor , Colorimetria , Facetas Dentárias , Humanos , Imersão , Teste de Materiais , Propriedades de Superfície , Temperatura , Fatores de Tempo , Água/química
15.
Biochem Pharmacol ; 159: 96-105, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30472240

RESUMO

Sepsis is an etiologically complex and often fatal inflammatory process involving a multitude of cytokine signaling pathways. Tumor necrosis factor α (TNFα) acts as a central regulator of the acute-phase inflammatory response by recruiting immune cells, including circulating monocyte/macrophages, to sites of infection or tissue damage. Inorganic polyphosphate (polyP), a linear polymer of orthophosphate residues, has been found in almost all cells and tissues, but its functions in immunity remain largely unknown. In this study, we show that pre- or post-treatment of mice with polyP150 (average chain length of 150 phosphate residues) markedly increases survival from lipopolysaccharide (LPS)-induced shock and inhibits macrophage recruitment to the liver and lungs, resulting in protection against tissue injury. In accord with these in vivo results, pretreatment of cultured peritoneal macrophages with polyP150 inhibited chemotaxis and actin polarization in response to TNFα. PolyP150 also inhibited phosphorylation of stress-activated protein kinases c-Jun N-terminal kinase (JNK) and p38, two downstream signaling molecules of the TNFα cascade, thereby preventing cyclooxygenase-2 gene expression by macrophages. These findings suggest that polyP150 inhibits recruitment of macrophages into organs by regulating the TNFα-JNK/p38 pathway, which may, in turn, protect against multi-organ dysfunction and lethality induced by LPS. Our findings identify polyP regulation as a novel therapeutic target for sepsis.


Assuntos
Lipopolissacarídeos/toxicidade , Macrófagos Peritoneais/efeitos dos fármacos , Polifosfatos/farmacologia , Choque Séptico/tratamento farmacológico , Animais , Quimiotaxia/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/patologia , Masculino , Camundongos Endogâmicos , Óxido Nítrico Sintase Tipo II/genética , Fosfatos/química , Fosfatos/farmacologia , Polifosfatos/química , Choque Séptico/induzido quimicamente , Choque Séptico/mortalidade , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
16.
Dent Mater J ; 38(2): 303-310, 2019 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-30713283

RESUMO

This study aimed to non-destructively analyze the progression of subsurface enamel caries using swept-source optical coherence tomography (SS-OCT), a recently developed imaging analysis modality. Artificial enamel caries at various stages of demineralization were created in bovine tooth enamel using a modified lactic acid gel system. Untreated enamel served as a control. OCT images from cross-sections of enamel were collected. Mineral density, distribution, and histological changes were analyzed using an electron probe microanalyzer, scanning electron microscopy, and contact microradiography. The Raman spectrum and X-ray structural analysis of the enamel surfaces were determined. SS-OCT detected significant differences in mineral loss among the samples. A high-brightness image was confirmed, along with changes in the respective brightness graphs proportionate to the degree of demineralization. SS-OCT can potentially be used to evaluate the progression of incipient enamel carious lesions.


Assuntos
Cárie Dentária , Desmineralização do Dente , Animais , Bovinos , Esmalte Dentário , Microrradiografia , Tomografia de Coerência Óptica
17.
Dent Mater J ; 38(1): 120-126, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30298855

RESUMO

The relationship between performance of caries detector dyes and solvent molecular weight has been reported, but viscosity has not yet been investigated. Therefore, using extracted human teeth, we compared 6 experimental caries detector dyes with different viscosities to clarify the relationship between dye viscosity and staining performance in sclerotic dentin. Carious dentin started showing dentin staining when stained with caries detector dyes with kinematic viscosity≥263 mm2/s, showed no immunoreactivity for Streptococcus mutans on immunohistochemistry, and contained dentinal tubules free of debris on scanning electron microscopy. Samples stained using a caries detector dye with kinematic viscosity of 332 mm2/s contained calcification product-like debris in the dentinal tubules. These findings suggest that the caries detector dye has a threshold kinematic viscosity between 263 and 332 mm2/s at which sclerotic dentin and tissues beyond are not stained. The caries detector dye appears to control tooth dyeability based on solvent viscosity.


Assuntos
Corantes/química , Cárie Dentária/diagnóstico , Propilenoglicóis/química , Rodaminas/química , Descoloração de Dente/induzido quimicamente , Dente Pré-Molar , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Dente Molar , Camada de Esfregaço , Propriedades de Superfície , Viscosidade
18.
J Dent ; 35(12): 923-9, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17935852

RESUMO

OBJECTIVE: Aim of this in vitro study was to investigate the correlation of shear bond strength and marginal cavity adaptation, together with polymerization shrinkage and contraction stress, using the combination of four self-etch adhesives and three resin composites. MATERIALS AND METHODS: Interactions were studied between one two-step and three one-step adhesives, and the hybrid-type resin composites, Beautifil (BEU, Shofu) and Venus (VEN, Heraeus), and an experimental nano-hybrid resin composite NEUN (NEU, Heraeus). For all 12 combinations shear bond strengths (SBS) were determined on human dentin. Marginal adaptation (MGW) was assessed in cylindrical butt-joint dentin cavities. Further, polymerization contraction and contraction stress of the resin restoratives were measured. RESULTS: Significant determinants of SBSs on dentin were time of testing (10min or 24h) and adhesives (p<0.001). Marginal adaptation was best for NEU, followed by VEN and BEU. Only the resin composite used was a highly significant determinant of cavity adaptation. Polymerization shrinkage after 5min was 2.58, 2.74, and 1.53% for BEU, VEN, and NEU, respectively. Polymerization contraction stresses were largest for BEU, less for VEN, and smallest for NEU (p<0.05). CONCLUSIONS: No correlation was found between bond strength and marginal cavity adaptation. In contrast, reduced shrinkage and low polymerization contraction stress of resin composites were identified as important determinants of marginal cavity adaptation.


Assuntos
Resinas Compostas/química , Colagem Dentária , Adesivos Dentinários/química , Bis-Fenol A-Glicidil Metacrilato/química , Preparo da Cavidade Dentária/classificação , Adaptação Marginal Dentária , Dentina/ultraestrutura , Humanos , Teste de Materiais , Metacrilatos/química , Nanoestruturas/química , Polímeros/química , Cimentos de Resina/química , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície
19.
Dent Mater J ; 26(3): 312-5, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17694737

RESUMO

The aim of this study was to evaluate tri-ethylene glycol mono-methacrylate (TEGMA) in terms of dermatological allergic reaction using a Guinea Pig Maximization Test. Skin reaction was evaluated according to the criteria of International Contact Dermatitis Research Group. TEGMA, as a constituent in new primers, has been reported to contribute to a priming ability similar to that of highly purified glyceryl mono-methacrylate (GM). In this study, it was found that its adverse effect was less than that of 2-hydroxy ethyl methacrylate (2-HEMA), but similar to that of highly purified GM. In conclusion, it was anticipated that TEGMA would hereafter replace 2-HEMA as a primer, as it posed a lower risk of triggering dermatological allergic reaction.


Assuntos
Adesivos Dentinários/efeitos adversos , Toxidermias/etiologia , Polietilenoglicóis/efeitos adversos , Ácidos Polimetacrílicos/efeitos adversos , Animais , Glicerídeos/efeitos adversos , Cobaias , Metacrilatos/efeitos adversos
20.
Biomed Mater Eng ; 28(3): 305-314, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28527193

RESUMO

BACKGROUND: The use of dental computer-aided design/computer-aided manufacturing (CAD/CAM) restoration is rapidly increasing. OBJECTIVE: This study was performed to evaluate the marginal and internal cement thickness and the adhesive gap of internal cavities comprising CAD/CAM materials using two digital impression acquisition methods and micro-computed tomography. METHODS: Images obtained by a single-image acquisition system (Bluecam Ver. 4.0) and a full-color video acquisition system (Omnicam Ver. 4.2) were divided into the BL and OM groups, respectively. Silicone impressions were prepared from an ISO-standard metal mold, and CEREC Stone BC and New Fuji Rock IMP were used to create working models (n=20) in the BL and OM groups (n=10 per group), respectively. Individual inlays were designed in a conventional manner using designated software, and all restorations were prepared using CEREC inLab MC XL. These were assembled with the corresponding working models used for measurement, and the level of fit was examined by three-dimensional analysis based on micro-computed tomography. RESULTS: Significant differences in the marginal and internal cement thickness and adhesive gap spacing were found between the OM and BL groups. CONCLUSIONS: The full-color movie capture system appears to be a more optimal restoration system than the single-image capture system.


Assuntos
Desenho Assistido por Computador , Planejamento de Prótese Dentária , Gravação em Vídeo , Microtomografia por Raio-X , Adaptação Marginal Dentária , Porcelana Dentária , Humanos , Propriedades de Superfície
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