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1.
Oper Dent ; 49(6): 673-681, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39407435

RESUMEN

OBJECTIVE: To evaluate the influence of battery level on power (mW), emission spectrum (mW/cm2/ nm), and light distribution on the active tip (mW/ cm2) of certified (FDA/ANVISA) and low-cost uncertified light-curing units (LCUs) purchased through e-commerce. METHODS: Seven LCUs, three certified: VALO Grand (Ultradent); Radii Xpert (SDI); and LED.B (Woodpecker); and four uncertified: 1 Sec; BS 300; LED curing light; and VAFU (VRN, AZDENT), were used. The LCUs were evaluated by calculating the power (mW) after each sequential five exposure cycles of 20 seconds and the emission spectrum (mW/cm2/nm) in the initial and final cycles, using an integrating sphere during three battery charging cycles. Beam profiling was used to check the light distribution on the LCU tip after every 50 exposure cycles until the battery fully discharged. Data were analyzed by linear regression between power and the number of exposure times (R2). RESULTS: The certified LCUs VALO Grand (R2=0.005), LED.B (R2=0.02), and Radii Xpert (R2=0.09) and the uncertified LCU VAFU (R2=0.002) had no significant power reduction during the three battery charging cycles. The uncertified LCUs BS 300 (R2=0.87), 1 Sec (R2=0.60), and LED curing light (R2=0.83) showed significant power reduction, decreasing the emission spectrum (mW/cm2/nm) at the end of the battery charging cycle. The light distribution on the active tip across the level battery was modified significantly with successive exposure times. CONCLUSIONS: The certified LCUs (VALO Grand, Radii Xpert, and LED.B) and uncertified LCU (VAFU), maintained power, emission spectrum, and light distributions during the tested battery life cycles. Low-cost certified LCU LED.B exhibited inhomogeneous light concentrated at the center of the tip. Low-cost uncertified LCUs-BS 300, 1 Sec, and LED curing light-had significant power reductions during the battery cycles and increased inhomogeneous light distribution along the successive exposure times.


Asunto(s)
Luces de Curación Dental , Suministros de Energía Eléctrica , Diseño de Equipo , Humanos
2.
Oper Dent ; 49(6): 704-713, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39407441

RESUMEN

OBJECTIVES: This study aimed to evaluate the impact of battery levels on the emission of a multi-peak cordless LED light-curing unit (LCU) and the effect on the degree of conversion (DC) and Knoop hardness (KH) of a light-cure resin luting agent activated through varying lithium disilicate (LiS2) ceramic thicknesses and translucencies. METHODS: High and low translucency LiS2 discs (IPS e.max Press HT and LT, respectively; shade A1) with thickness of 0.5, 1.0, 1.5, and 2.0 mm were fabricated. Resin luting agent specimens (Variolink Esthetic LC) were prepared and cured using a Bluephase G2 LCU at different battery levels (100%, 50%, and 10%) through the LiS2 ceramics. The transmitted irradiance was evaluated using USB4000 MARC, while FTIR and a microhardness tester assessed DC and KH, respectively. After ensuring homoscedasticity, the data wee analyzed using analysis of variance and Tukey HSD test (α=0.05). RESULTS: The study found strong positive correlations between battery levels and irradiance, particularly with no ceramic interposition and through HT ceramics (R2=0.9471), although this correlation diminished with thicker HT (R2=0.7907) and LT ceramics (R2<0.2980). Both battery levels and ceramic thickness significantly influenced transmitted irradiance (p<0.0001), resulting in lower values with decreased battery levels and increased ceramic thicknesses (p<0.0001). LT ceramics showed lower transmittance than HT. DC was significantly affected by both battery levels and ceramic thicknesses, with generally lower DC values except for LT ceramics at a 10% battery level (p<0.0001). No significant differences in DC were observed between HT and LT translucencies (p=0.548). KH was higher in HT than LT ceramics at 100% and 50% battery levels, with thicker ceramics showing lower KH values at 10% battery level (p<0.0001). Conclusion: Reduced battery levels in cordless LED curing units significantly affect the irradiance, degree of conversion, and hardness of light-curable resin luting agents. Maintaining battery levels above 50% is recommended for optimal performance. Thicker and more opaque ceramics significantly impacted incident irradiance. However, preserving radiant energy could potentially mitigate these limitations.


Asunto(s)
Luces de Curación Dental , Porcelana Dental , Ensayo de Materiales , Cementos de Resina , Suministros de Energía Eléctrica , Dureza , Curación por Luz de Adhesivos Dentales/métodos , Cerámica , Humanos , Espectroscopía Infrarroja por Transformada de Fourier
3.
Oper Dent ; 49(5): 540-550, 2024 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-39135205

RESUMEN

PURPOSE: This study aimed to assess the impact of battery levels in single-peak and multi-peak light-curing units (LCUs) on irradiance, and their effects on glass fiber post push-out bond strength to root dentin and the degree of conversion of dual-cure universal resin cement. METHODS AND MATERIALS: Sixty bovine roots underwent endodontic treatment and were randomly distributed into 6 groups (n=10), formed by combining two LCUs (single-peak and multipeak) and three battery levels (100%, 50%, and 10%). A spectrophotometer measured irradiance (mW/ cm2) and spectral irradiance (mW/cm2/nm). Push-out bond strength (PBS) tests occurred at three root regions (cervical, middle, and apical), with optical and scanning electron microscopy for failure mode analysis. Degree of conversion (DC) was evaluated across the root regions. Data were analyzed using two-way repeated measures ANOVA and the Tukey HSD test. The Fisher exact test verified failure modes (α=0.05). RESULTS: As multipeak LCU battery levels decreased, emitted irradiance also diminished, with notable PBS reductions in the apical thirds. Failure modes were influenced by different conditions, primarily exhibiting mixed modes. Battery levels significantly impacted DC in the multipeak LCU, particularly in the cervical region, while the single-peak LCU exhibited DC reduction at the 10% battery level in the cervical region. CONCLUSIONS: Emitted irradiance, resin cement DC, and glass fiber post bond strength to root dentin may be influenced by varying cordless LCUs and battery levels.


Asunto(s)
Luces de Curación Dental , Vidrio , Técnica de Perno Muñón , Cementos de Resina , Cementos de Resina/química , Bovinos , Técnica de Perno Muñón/instrumentación , Animales , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Recubrimiento Dental Adhesivo/métodos , Análisis del Estrés Dental , Curación por Luz de Adhesivos Dentales/métodos , Técnicas In Vitro , Dentina
4.
Med Oral Patol Oral Cir Bucal ; 29(6): e734-e741, 2024 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-39088720

RESUMEN

BACKGROUND: This study aimed to explore the clinical, histopathologic, and immunohistochemical characteristics of myofibromas (MFs) affecting the head and neck region. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded tissue blocks of patients diagnosed with MFs in the head and neck were retrieved from the archives of three oral and maxillofacial pathology laboratories. Data including clinical, radiographic, microscopic and immunohistochemical findings, treatment employed, and follow-up status were retrieved from the patient's medical records or pathology reports. RESULTS: Sixteen cases were included in the study. Females were slightly more affected than males. The first and second decades of life were more prevalent. The most common locations were the alveolar ridge and cheek. Although rare, some of the patients were presented with intraosseous lesions. Microscopically, tumors consisted of plump, spindle-shaped myofibroblasts arranged in whorls or fascicles with varying degrees of differentiation. Immunohistochemically, diffuse positivity for vimentin and α-SMA was observed, while Ki-67 mostly showed low immunoreactivity (<5%). Treatment primarily involved complete excision. CONCLUSIONS: MFs in the head and neck region are rare and predominantly affect female patients during the second decade of life. Despite their rarity, central MFs should be considered in the differential diagnosis of intraosseous lesions in infants.


Asunto(s)
Neoplasias de Cabeza y Cuello , Miofibroma , Humanos , Femenino , Masculino , Miofibroma/patología , Miofibroma/diagnóstico , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/diagnóstico , Niño , Adulto , Preescolar , Adolescente , Adulto Joven , Lactante , Persona de Mediana Edad , Estudios Retrospectivos
5.
Oper Dent ; 49(4): 421-431, 2024 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-38978305

RESUMEN

OBJECTIVES: This study evaluated the depth of cure (DoC) of eight resin-based composites (RBCs) photocured using one multipeak light-curing unit (LCU) on the standard output setting for the manufacturer's RBC recommended exposure time and at a higher irradiance for 3 seconds. METHODS: Three conventional RBCs: Tetric EvoCeram (Evo), Tetric N-Ceram (Cer), Tetric Prime (Pri); and five bulk-fill: Tetric N-Ceram Bulk Fill (CerBF), Opus Bulk Fill APS (OpusBF), Opus Bulk Fill Flow APS (OpusF), Tetric PowerFill (PFill) and Tetric PowerFlow (PFlow) were examined. Only PFill and PFlow are formulated to be photocured in 3 seconds. The RBCs were packed into a metal mold and photocured using a Bluephase PowerCure LCU for the RBC manufacturer's recommended exposure time on the standard mode and using the 3-second high irradiance mode. After photocuring, the specimens were immersed in a solvent for 1 hour. The length of the remaining RBC was measured and divided by 2. Data were analyzed using two-way analysis of variance (ANOVA) followed by the Tukey post hoc multiple comparison test (α=0.05). RESULTS: There was no significant difference in the DoC values for PFill and PFlow when photocured using the 3-second high irradiance protocol compared to the lower irradiance standard mode protocol. All other RBCs had significantly lower DoC values (p<0.001) when photocured off-label using the 3-second high irradiance mode. CONCLUSION: Of the eight RBCs tested, only PFill and PFlow achieved the same DoC when the high irradiance 3-second curing method was used compared to when their longer lower irradiance protocol was used.


Asunto(s)
Resinas Compuestas , Luces de Curación Dental , Ensayo de Materiales , Resinas Compuestas/uso terapéutico , Humanos , Factores de Tiempo , Polimerizacion , Curación por Luz de Adhesivos Dentales/métodos , Materiales Dentales/uso terapéutico , Materiales Dentales/química , Metacrilatos , Propiedades de Superficie
6.
Oper Dent ; 49(2): 210-221, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38349816

RESUMEN

OBJECTIVES: This study aimed to evaluate the optical and mechanical performance of two single-shade resin-based composites (RBCs) compared to those of a conventional RBC for restoring posterior teeth. METHODS: Two single-shade RBCs, Omnichroma (Tukoyama) and Vittra Unique APS (FGM), and a conventional RBC, Filtek Z350XT shade A2 (3M Oral Care), were evaluated in this study. The optical shade-matching performance was measured using a spectrophotometer. The light emitted by VALO Grand (Ultradent) and transmitted through the 2.0-mm RBC specimens was evaluated using beam profiling. Knoop hardness (KH, N/mm2), degree of conversion (DC, %) at the top and bottom, flexural strength (FS, MPa), elastic modulus (E, GPa), postgel shrinkage (Shr, %), and shrinkage stress (MPa) were evaluated. Scanning electron microscopy (SEM) was used to characterize the filler. Data for FS, E, and Shr were analyzed by one-way analysis of variance (ANOVA) and KH and DC by repeated one-way ANOVA measurement followed by Tukey test (α=0.05). The modified von Mises stress values, light transmission, and SEM images were analyzed qualitatively. RESULTS: All single-shade RBCs exhibited higher chromatic adaptation than the Filtek Z350XT (p<0.001). Omnichroma exhibited less color difference than Vittra Unique APS, irrespective of the shade. The light transmitted through Omnichroma and Vittra Unique APS increased during polymerization. KH and DC values were significantly reduced from the top to the bottom of the specimens for all RBCs (p<0.001); however, the ratio values were always higher than 80%. In general, all RBCs demonstrated similar mechanical properties. All RBCs exhibited a similar FS (p=0.083) and Shr value (p=0.144). Filtek Z350XT exhibited significantly higher E (p<0.001) than both single-shade RBCs. All RBCs exhibited similar shrinkage stress during restoration and similar residual stress during occlusal loading. CONCLUSIONS: Single-shade Omnichroma and Vittra Unique APS increased light transmission during light-activation, demonstrating better chromatic adaptation than conventional Filtek Z350XT. In general, Omnichroma and Vittra Unique APS exhibited similar mechanical properties and shrinkage stress distributions as Filtek Z350XT during light-activation and occlusal loading.


Asunto(s)
Resinas Compuestas , Materiales Dentales , Estrés Mecánico , Resinas Compuestas/uso terapéutico , Módulo de Elasticidad , Dureza , Ensayo de Materiales , Polimerizacion
7.
Oper Dent ; 49(2): 157-165, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38349817

RESUMEN

OBJECTIVES: To evaluate the volume and depth of enamel loss promoted by 37.5% and 7.5% hydrogen peroxide (HP) gels, and quantify the loss of calcium (Ca) and phosphate (P) ions by using ion chromatography (IC) analysis after bleaching. METHODS: Sixty bovine enamel specimens were randomly divided into three groups: Control - no bleaching gel; HP37.5%, application of HP 37.5% for 45 minutes for 14 days; and HP7.5%, application of HP 7.5% for 3 applications of 8 minutes. The surface analysis (n=5) was performed using a scanning electron microscope (SEM) and dispersive energy system (EDS) to calcium and phosphorus dosage. The micro-CT was used for the enamel loss analysis (n=5). IC was used to analyze extracted Ca and P (n=10). Data were analyzed by one-way ANOVA and two-way repeated measures ANOVA, followed by Tukey and Dunnett's tests (α=0.05). RESULTS: Significantly higher volume and depth of enamel loss were found for bleached groups compared with the control group. HP7.5% had significantly higher enamel change than HP37.5%. SEM showed higher enamel porosity for HP37.5% and HP7.5% compared to control. The IC demonstrated a significant increase of Ca incorporated into the gel, however, only HP7.5% had a higher P presence than the control group. The HP7.5% showed higher Ca and P ion exchange than HP37.5% (p<0.001). CONCLUSION: HP37.5% and HP7.5%, caused enamel mineral changes compared with the control group. The IC method was demonstrated to be an effective methodology for detecting enamel mineral loss by the bleaching gel.


Asunto(s)
Blanqueadores Dentales , Blanqueamiento de Dientes , Animales , Bovinos , Calcio , Blanqueamiento de Dientes/métodos , Esmalte Dental , Microtomografía por Rayos X , Peróxido de Hidrógeno/química , Minerales , Fosfatos , Geles
8.
Oper Dent ; 49(2): 136-156, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38349819

RESUMEN

OBJECTIVES: To evaluate the effect of the different radiant exposures from a multipeak light curing unit on the physical and mechanical properties of flowable and high-viscosity bulk-fill resin-based composites (RBC). METHODS: Five flowable bulk-fill RBCs (Tetric N-Flow Bulk-fill, Ivoclar Vivadent; Filtek Bulk Fill Flow, 3M Oral Care; Opus Bulk Fill Flow APS, FGM; Admira Fusion x-base, Voco and; and SDR Plus Bulk Fill Flowable, Dentsply Sirona) and five high-viscosity bulk-fill RBCs (Tetric N-Ceram Bulk-fill, Ivoclar Vivadent; Filtek One Bulk Fill, 3M Oral Care; Opus Bulk Fill APS, FGM; Admira Fusion x-tra, Voco; and SonicFill 2, Kerr) were photo-cured using a VALO Cordless light (Ultradent) for 10, 20, and 40 seconds at an irradiance of 1200, 800, or 400 mW/cm2, resulting in the delivery of 4, 8, 12, 16, 24, 32, or 48 J/cm2. Post-gel shrinkage (Shr) was calculated using strain-gauge test. The degree of conversion (DC, %) was calculated using FTIR. Knoop hardness (KH, N/mm2) and elastic modulus (E, MPa) were measured at the top and bottom surfaces. Logarithmic regressions between the radiant exposures and mechanical properties were calculated. Radiodensity was calculated using digital radiographs. Data of Shr and radiodensity were analyzed using two-way analysis of variance (ANOVA), and the DC, KH, and E data were analyzed with two-way ANOVA using split-plot repeated measurement tests followed by the Tukey test (a = 0.05). RESULTS: Delivering higher radiant exposures produced higher Shr values (p<0.001) and higher DC values (R2=0.808-0.922; R2=0.648-0.914, p<0.001), KH (R2=0.707-0.952; R2=0.738-0.919; p<0.001), and E (R2=0.501-0.925; R2=0.823-0.919; p<0.001) values for the flowable and high-viscosity RBCs respectively. Lower KH, E and Shr were observed for the flowable bulk-fill RBCs. All bulk-fill RBCs had a radiopacity level greater than the 4-mm thick aluminum step wedge. The radiant exposure did not affect the radiopacity. CONCLUSION: The Shr, DC, KH, and E values were highly correlated to the radiant exposure delivered to the RBCs. The combination of the higher irradiance for longer exposure time that resulted in radiant exposure between 24 J/cm2 to 48 J/cm2 produced better results than delivering 400 mW/cm2 for 40 s (16 J/cm2), and 800 mW/cm2 for 20 seconds (16 J/cm2) or 1200 mW/cm2 for 10 seconds (12 J/cm2). All the bulk-fill RBCs were sufficiently radiopaque compared to 4 mm of aluminum.


Asunto(s)
Resinas Acrílicas , Aluminio , Resinas Compuestas , Metacrilatos , Poliuretanos , Siloxanos , Viscosidad , Ensayo de Materiales , Polimerizacion , Materiales Dentales , Propiedades de Superficie
9.
Med Oral Patol Oral Cir Bucal ; 29(1): e78-e86, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37471301

RESUMEN

BACKGROUND: Lymphomas affecting the submandibular glands are very uncommon and few reports are currently available in the literature. Therefore, the aim of the current study is to describe the clinical and microscopic features of an original series of lymphomas affecting the submandibular glands. MATERIAL AND METHODS: The pathology files of two institutions were searched for lymphoma cases affecting the submandibular glands. The original hematoxylin and eosin, and immunohistochemical slides were revised by a pathologist for diagnosis confirmation following the revised 4th edition of the World Health Organization classification of tumours of haematopoietic and lymphoid tissues. Clinical data regarding age, sex, clinical manifestation, treatment, follow-up and status at last appointment were retrieved from the patients' medical charts. RESULTS: During the period investigated, 16 cases were included in the study. Females predominated (10:6) with a mean age of 57.8 years-old. Tumors usually presented as asymptomatic swellings. MALT lymphoma represented the most common subtype, followed by diffuse large B cell lymphoma and follicular lymphoma. Three patients died, one of them affected by plasmablastic lymphoma, one by DLBCL and one by MALT lymphoma. CONCLUSIONS: Low-grade B cell lymphomas predominate in the submandibular glands, but DLBCL and other subtypes may also be rarely diagnosed in this salivary gland.


Asunto(s)
Linfoma de Células B de la Zona Marginal , Linfoma de Células B Grandes Difuso , Femenino , Humanos , Persona de Mediana Edad , Linfoma de Células B de la Zona Marginal/diagnóstico , Linfoma de Células B de la Zona Marginal/patología , Linfoma de Células B de la Zona Marginal/terapia , Glándula Submandibular/patología , Glándulas Salivales , Linfoma de Células B Grandes Difuso/patología
11.
Oper Dent ; 2023 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-37881034

RESUMEN

OBJECTIVES: This study evaluated the Knoop hardness (KH, N/mm2) and degree of conversion (DC, %) on the margins of light-cured resin cements with different photoinitiators using a single light-curing unit (LCU) with two heads (mono- and multiwave). METHODS AND MATERIALS: Three types of resin cements were used with different photoinitiators: Megalink Esthetic (Odontomega, São Paulo, Brazil) with a camphorquinone photoinitiator; Allcem Veneer (FGM, Joinville, Brazil) with the Advanced Polymerization system (APS), and Variolink Esthetic LC (Ivoclar Vivadent, Schaan, Liechtenstein). Thirty samples were collected and divided into six groups (n=5 each). The resin cement samples were made into the shape of a maxillary right central incisor and photoactivated under a 0.5-mm-thick ceramic sheet. A single LCU (Radii Xpert, SDI) with two heads (mono- and multiwave) was used. The tip of the LCU was positioned at the center of the sample in a standardized manner. Raman spectroscopy was performed to evaluate the DC, and KH was evaluated through the Knoop microhardness test. Five regions were evaluated: cervical, mesial, buccal (center), distal, and incisal. RESULTS: There was a significant difference in the DC only for the type of cement (p<0.001), indicating that the cement with the APS photoinitiator presented excellent results. There were significant differences in the type of cement (p<0.001), type of light (p<0.001), region (p<0.001), and the interaction between the type of cement and type of light (p<0.001). The resin cement with the APS photoinitiator cured with monowave light showed the highest KH values. The beam profiles of all groups, with and without the interposition of ceramic and resin cement, were examined by light transmission. CONCLUSIONS: The cement with the APS photoinitiator presented the best results with respect to the DC and KH. In comparison with mono- and multiwaves, the LCU may not be a determining factor for the properties of light-cured resin cements. The buccal region showed the best results for DC and KH, indicating the need for a greater amount of light-curing at the cementation margins.

12.
Oper Dent ; 48(3): 304-316, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-36917633

RESUMEN

OBJECTIVES: To analyze the effect of using the resin-based composite manufacturer's recommended exposure time on the degree of conversion (DC), Knoop hardness (KH), and elastic modulus (E) of conventional and bulk-fill resin-based composites (RBCs). METHODS: Three resin-based composites (RBCs) were tested: Tetric EvoCeram Bulk Fill (TET), Opus Bulk Fill APS (OPU), and RBC Vittra APS (VIT). They were photo-activated in 2 mm deep, 6 mm diameter molds for their recommended exposure times of 10 seconds, 20 seconds, or 40 seconds from four light-curing units (LCUs). Two delivered a single emission peak in the blue light region (Optilight Max and Radii-Cal) and two delivered multiple emission peaks in the violet and blue region (VALO Cordless and Bluephase G2). After 24 hours of dry storage at 37°C in the dark, the KH (Kgf/mm2), E (MPa) and DC (%) at the top and bottom surfaces of specimens (n=5) were measured and the results analyzed by 2-way analysis of variance (ANOVA) followed by a Tukey test (α=0.05). RESULTS: The irradiance (mW/cm2) and spectral irradiance (mW/cm2/nm) from the LCUs were reduced significantly (8-35%) after passing through 2.0 mm of RBC (p<0.001). The DC at the bottom of VIT and TET was less than at the top surface (p<0.001). OPU had the same DC at the top and bottom surface (p=0.341). The KH and E values at the top surface of VIT and TET were substantially higher than at the bottom (p<0.001). OPU exposed for 40 seconds achieved higher mechanical properties than TET that was photo-activated for 10 seconds (p<0.001). The opacity of different bulk-fill RBCs changed differently during the polymerization; OPU became more opaque, whereas TET became more transparent. When exposed for their recommended times, the 2 mm thick RBCs that used Ivocerin or the APS photoinitiator system were adequately photo-activated using either the single or multiple emission peak LCUs (p=0.341). CONCLUSION: After 24 hours' storage, all the 2 mm thick RBCs photo-cured in 6 mm diameter molds achieved a bottom-to-top hardness ratio of at least 80% when their recommended exposure times were used. TET, when photo-activated for 10 seconds, achieved lower mechanical properties than OPU that had been photo-activated for 40 seconds. The change in opacity of the RBCs was different during photo-activation.


Asunto(s)
Luces de Curación Dental , Curación por Luz de Adhesivos Dentales , Curación por Luz de Adhesivos Dentales/métodos , Ensayo de Materiales , Materiales Dentales , Resinas Compuestas , Dureza , Polimerizacion , Propiedades de Superficie
13.
Oper Dent ; 48(2): 226-235, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36786761

RESUMEN

OBJECTIVES: This study evaluated the influence of the thickness of disilicate ceramic on the light attenuation (mW/cm2), degree of conversion (DC, %), Knoop hardness (KH, N/mm2) and the elastic modulus (E, MPa) of four luting resins. METHODS: Three resin cements: RelyX Veneer (RV, 3M Oral Care, Monrovia, CA USA); Allcem Veneer APS (AC, FGM); Variolink Esthetic LC (VE, Ivoclar Vivadent, Schaan, Liechtenstein) and one flowable resin composite Tetric N-Flow (TF, Ivoclar Vivadent) were photocured for 20 seconds. The irradiance (mW/cm2) and emission spectrum (mW/cm2/nm) from a broad-spectrum LED light unit (Bluephase G2, Ivoclar Vivadent) were measured over the luting material (control) and through 0.3 mm, 0.7 mm, and 1.0 mm thick ceramic discs (e.max CAD, Ivoclar Vivadent). RESULTS: The LED light delivered 26.1 J/cm2 to the surface and 6.2 J/cm2 through the 1.0 mm thick ceramic. The distribution of violet and blue light across the light tip of the light-curing unit (LCU) was relatively homogeneous, but there was less violet range. The irradiance and spectral radiant power decreased significantly as the ceramic thicknesses increased (p<0.001). The luting material type had significant effect on KH and E values (p<0.001). The RV had the greatest KH and E values, and VE had the lowest. Ceramic thickness had no significant effect on KH (p=0.213) and E (p=0.130). The KH (p=0.265) and E (p=0.165) were also not influenced by the location where these measurements were made across the specimens. No significant reduction of the DC was observed as the ceramic thickness increased (p=0.311). CONCLUSION: Increasing the ceramic thickness exponentially reduced the irradiance. This reduction was more pronounced at the shorter wavelengths (violet) of light, with an 82% decrease for 1 mm-thick ceramic. Increasing the ceramic thickness did not affect the DC, irrespective of photoinitiators used in the tested resins. The position of the violet and blue LEDs within the body of the LCU did not influence KH or E in any of the resins tested. The KH and E of VE were significantly lower than the other 3 luting materials tested.


Asunto(s)
Resinas Compuestas , Porcelana Dental , Módulo de Elasticidad , Dureza , Cerámica , Cementos de Resina , Ensayo de Materiales , Propiedades de Superficie
14.
Braz J Biol ; 83: e264875, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36651450

RESUMEN

This study aimed to analyze the phytochemical profile of essential oil obtained from the leaves of Coriandrum sativum L., and its antifungal activity against Candida spp. The research consisted of an in vitro study including collecting the vegetable product, analysis of its macronutrients, extraction, and chemical analysis of the essential oil, and assaying antifungal activity through minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), with growth inhibition kinetics, and the product's effects on multi-species Candida biofilm. Nitrogen (47.08 g Kg-1), phosphorus (5.3 g Kg-1) and potassium (50.46 g Kg-1) levels were within the normal range. The major constituents were octanal, decanal, dec-(2E)-enal, and dodecanal. The MIC and MFC of the product evaluated against 11 tested Candida strains ranged from 31.25 to 250 µg/mL. There was inhibition of fungal growth during 24 hours of exposure at the 3 concentrations tested (250, 125, and 62.5 µg/mL). The concentration of 80 mg/mL promoted the greatest reduction in multispecies biofilm (70% reduction in biofilm). Coriandrum sativum L. essential oil extract is principally constituted of alcohols and aldehydes and presents fungicidal activity against Candida spp. in its in planktonic and biofilm forms.


Asunto(s)
Coriandrum , Aceites Volátiles , Antifúngicos/farmacología , Candida , Plancton , Aceites Volátiles/farmacología , Biopelículas , Pruebas de Sensibilidad Microbiana
15.
Oper Dent ; 48(2): 207-217, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36656320

RESUMEN

OBJECTIVE: This study aimed to evaluate the effect of activated charcoal toothpaste on the color stability of teeth subjected to tooth bleaching and pigmenting agents. METHODS: A total of 120 bovine crowns were randomly divided into 12 groups (n=10) according to two study factors: staining solutions (three levels): saliva (control), coffee, and red wine; and toothpaste (four levels): BPC, Bianco Pro Clinical (Bianco Oral Care) (Control); BIW, Black is White (Curaprox); BCA, Bianco Carbon (Bianco Oral Care); and NAT, Natural Suavetex (Suavetex). The samples were subjected to office bleaching with a 35% hydrogen peroxide-based gel (Whiteness HP Blue, FGM), followed by immersion in the solution for 45 minutes per day and daily toothbrushing for 7 days. The color (ΔE) and luminosity changes (ΔL*) were measured using reflectance spectroscopy (Vita EasyShade). The CIE values (L*, a*, b*) were measured at baseline after bleaching (T0) and immediately after immersion in solution each day (Ti1-Ti7) and after all toothbrushing cycles (Tb1-Tb7). ΔE and ΔL were analyzed using a two-way analysis of variance and Tukey's test (α=0.05). The clinically unacceptable level of ΔE > 3.3 was used to evaluate the color change. RESULTS: The color change was significantly influenced by the staining solutions and toothpastes (p<0.001). The color change (ΔE) was significantly higher when immersed in wine than in coffee, and lower ΔE values were observed for artificial saliva (control), irrespective of the toothpaste used. In artificial saliva, BPC, BIW, and BCA resulted in significantly lower ΔE values than NAT, which presented a clinically unacceptable level of dental color change (ΔE>3.3). Coffee resulted in a lower (L*) reduction than wine, irrespective of the toothpaste used. CONCLUSION: Charcoal toothpastes resulted in a color change on the surface of the tooth enamel (ΔE). The bleaching effect of the charcoal toothpastes and control evaluated in this study partially reduced the color changes on the surface of the tooth enamel caused by staining solutions but was unable to reestablish the measured values to the baseline. For teeth immersed in artificial saliva, the color change was not noticeable in BCA, BIW, and control-BPC (ΔE≥3.3), except for NAT, which showed a significant color change.


Asunto(s)
Blanqueamiento de Dientes , Animales , Bovinos , Carbón Orgánico , Café , Color , Saliva Artificial , Blanqueamiento de Dientes/métodos , Pastas de Dientes/química
16.
Arq. bras. med. vet. zootec. (Online) ; 75(3): 535-543, 2023. tab, graf
Artículo en Inglés | VETINDEX | ID: biblio-1436957

RESUMEN

O presente estudo avaliou o potencial probiótico in vitro de bactérias ácido-láticas (BAL) isoladas de queijo artesanal da Serra Geral (MG), com 14 e 21 dias de maturação, leite cru e pingo, utilizados em sua elaboração, e de bancadas de produção. As bactérias foram submetidas aos testes de antibiograma, à tolerância a ácido gástrico artificial e a sais biliares e ao antagonismo contra micro-organismos indicadores. Levilactobacillus brevis (Q521) e Lactococcus lactis (LLSG) apresentaram os melhores resultados e foram selecionados para a produção de leite fermentado. Apenas LLSG foi capaz de fermentar o leite. O produto apresentou qualidade microbiológica e físico-química adequada, exceto para os teores de proteína, segundo a legislação vigente para leites fermentados, demonstrando potencial tecnológico. A partir dos resultados apresentados, sugere-se que testes in vivo sejam realizados para que LLSG possa vir a ser utilizado como probiótico.


Asunto(s)
Técnicas In Vitro , Queso/microbiología , Probióticos , Alimentos Funcionales
17.
Braz. j. biol ; 83: e264875, 2023. tab, graf
Artículo en Inglés | VETINDEX | ID: biblio-1417538

RESUMEN

This study aimed to analyze the phytochemical profile of essential oil obtained from the leaves of Coriandrum sativum L., and its antifungal activity against Candida spp. The research consisted of an in vitro study including collecting the vegetable product, analysis of its macronutrients, extraction, and chemical analysis of the essential oil, and assaying antifungal activity through minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), with growth inhibition kinetics, and the product's effects on multi-species Candida biofilm. Nitrogen (47.08 g Kg-1), phosphorus (5.3 g Kg-1) and potassium (50.46 g Kg-1) levels were within the normal range. The major constituents were octanal, decanal, dec-(2E)-enal, and dodecanal. The MIC and MFC of the product evaluated against 11 tested Candida strains ranged from 31.25 to 250 µg/mL. There was inhibition of fungal growth during 24 hours of exposure at the 3 concentrations tested (250, 125, and 62.5 µg/mL). The concentration of 80 mg/mL promoted the greatest reduction in multispecies biofilm (70% reduction in biofilm). Coriandrum sativum L. essential oil extract is principally constituted of alcohols and aldehydes and presents fungicidal activity against Candida spp. in its in planktonic and biofilm forms.


Este trabalho teve como objetivo analisar o perfil fitoquímico do óleo essencial obtido das folhas de Coriandrum sativum L., e sua atividade antifúngica contra Candida spp. A pesquisa consistiu em um estudo in vitro incluindo a coleta do produto vegetal, análise de seus macronutrientes, extração e análise química do óleo essencial e ensaio da atividade antifúngica por meio da concentração inibitória mínima (CIM) e concentração fungicida mínima (MFC), com crescimento cinética de inibição e os efeitos do produto no biofilme de Candida multi-espécies. Os níveis de nitrogênio (47,08 g Kg-1), fósforo (5,3 g Kg-1) e potássio (50,46 g Kg-1) estavam dentro da normalidade. Os principais constituintes foram octanal, decanal, dec-(2E)-enal e dodecanal. A CIM e CFM do produto avaliado contra 11 cepas de Candida testadas variaram de 31,25 a 250 µg/mL. Houve inibição do crescimento fúngico durante 24 horas de exposição nas 3 concentrações testadas (250, 125 e 62,5 µg/mL). A concentração de 80 mg/mL promoveu a maior redução no biofilme multiespécies (redução de 70% no biofilme). O extrato do óleo essencial de Coriandrum sativum L. é constituído principalmente por álcoois e aldeídos e apresenta atividade fungicida contra Candida spp. em suas formas planctônicas e biofilme.


Asunto(s)
Candida , Candidiasis/tratamiento farmacológico , Aceites Volátiles/análisis , Coriandrum/química , Antifúngicos/análisis , Plantas Medicinales/química , Biopelículas
19.
Oper Dent ; 47(4): 412-424, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35917253

RESUMEN

OBJECTIVES: This study evaluated the influence of irradiance/exposure time on the Knoop hardness (KHN) and polymer cross-linking density (PCLD), as well as microtensile bond strength (µTBS), nanoleakage (NL), and in situ degree of conversion (DC) of universal adhesives. METHODS AND MATERIALS: Two universal adhesive systems, Clearfil Universal Bond Quick (CUQ) and Scotchbond Universal Adhesive (SBU), were light-cured using various irradiance/exposure times: 1400 mW/cm2 for 5 s (1400*5); 1400 mW/cm2 for 10 s (1400*10); 3200 mW/cm2 for 5 s (3200*5); and 3200 mW/cm2 for 10 s (3200*10). Adhesive disks from each group were used to measure PCLD by KHN. One hundred and twenty-eight human molars were randomly assigned to 16 groups according to the following variables: adhesive system vs adhesive strategies vs radiance/exposure times. After restoration, specimens were sectioned into resin-dentin sticks and tested for µTBS, NL, and DC. The data from PCLD (%), KHN, µTBS (MPa), NL (%), and DC (%) data were subjected to ANOVA and Tukey's test (α=0.05). RESULTS: Significant reductions in KHN, µTBS, and DC (p=0.00001) values and an increase in NL and PCLD (p=0.00001) values were observed for 3200*10 when compared with other groups. Higher KHN, µTBS, and DC (p=0.000001) values were observed for 3200*5 in comparison with the other groups. The 1400*5 (7 J/cm2) and 1400*10 (14 J/cm2) groups showed intermediate values (p=0.000001). CONCLUSION: Although similar results in terms of hardness, polymer cross-linking density and nanoleakage were observed when 5 seconds at 3200 mW/cm2 and 10 seconds at 1400 mW/cm2 groups were compared, the use of higher irradiance (3200 mW/cm2) for only 5 seconds showed better results in terms of bond strength and degree of conversion for both universal adhesives to dentin. The prolonged exposure time (10 seconds) at the higher irradiance (3200 mW/cm2) showed the worst results.


Asunto(s)
Recubrimiento Dental Adhesivo , Filtración Dental , Adhesivos , Resinas Compuestas/química , Cementos Dentales/química , Dentina , Recubrimientos Dentinarios/química , Humanos , Ensayo de Materiales , Cementos de Resina/química , Resistencia a la Tracción
20.
Oper Dent ; 47(2): 163-172, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35604828

RESUMEN

OBJECTIVE: To evaluate the effect of the sample preparation and light-curing units (LCUs) on the Knoop hardness (KH, N/mm2) and degree of conversion (DC, %) of bulk-fill resin-based composite restorations. METHODS: Two molds were made using human molar teeth embedded in acrylic resin. One was a conventional tooth mold where the molar received a mesio-occluso-distal (MOD) preparation. In the other, the tooth was sectioned in three slices (buccal, middle, and lingual). The center slice received a MOD preparation similar to the conventional mold. Both tooth molds were placed in the second mandibular molar position in a Dentoform with a 44-mm interincisal opening. Restorations were made using Opus Bulk Fill (FGM) high viscosity bulk-fill resin-based composite (RBC) and light cured using two different lights: VALO Cordless (Ultradent) and Bluephase G2 (Ivoclar Vivadent). The RBC was placed in one increment that was light-cured for a total of 80 seconds (40 seconds at the occluso-mesial and occluso-distal locations). The RBC specimens were then prepared as follows: EmbPol - tooth mold specimen was embedded in polystyrene resin and polished before testing; Pol - tooth mold specimen was not embedded, but was polished before testing; NotPol - sectioned tooth mold, specimen not embedded nor polished before testing. The KH was measured in different depths and regions of the specimens, and the DC was measured using Raman spectroscopy. RESULTS: The results were analyzed using a 2-way analysis of variance (ANOVA) or repeated measures followed by the Tukey post-hoc test (α=0.05). The preparation method (p<0.001), depth of restoration (p<0.001), and the interaction between method and depth (p=0.003) all influenced the KH values. Preparation method (p<0.001), tooth region (p<0.001), and the interaction between method and tooth region (p=0.002) all influenced DC values. The KH values were reduced significantly from the top to the bottom of the restorations and also at the proximal box when compared with the occlusal region. This outcome was most significant in the proximal boxes. The NotPol method was the most effective method to detect the effect of differences in KH or DC within the restoration. A lower DC and KH were found at the gingival regions of the proximal boxes of the restorations. When the KH and DC values were compared, there were no significant differences between the LCUs (KH p=0.4 and DC p=0.317). CONCLUSION: Preparation methods that embedded the samples in polystyrene resin and polished the specimens reduced the differences between the KH and DC values obtained by different preparation techniques. The NotPol method was better able to detect differences produced by light activation in deeper areas.


Asunto(s)
Luces de Curación Dental , Curación por Luz de Adhesivos Dentales , Resinas Compuestas/química , Materiales Dentales/química , Dureza , Humanos , Ensayo de Materiales , Polimerizacion , Poliestirenos
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