Light transmittance and depth of cure of a bulk fill composite based on the exposure reciprocity law

Abstract The objective of this study was to evaluate the effect of the exposure reciprocity law of a multi-wave light-emitting diode (LED) on the light transmittance (LT), depth of cure (DOC) and degree of conversion in-depth (DC) of a bulk fill composite. A bulk fill composite (EvoCeram® bulk fill, Ivoclar Vivadent) was photoactivated using the multi-wave LED (VALO™ Cordless, Ultradent). The LED was previously characterized using a spectrophotometer to standardize the time of exposure when using the Standard or Xtra-Power modes with the same radiant exposure of 20J/cm2. LT was evaluated through samples of the bulk fill composite every millimeter till 4 mm in-depth. DOC was evaluated according to the ISO 4049. DC of the central longitudinal cross-section from each sample of the DOC test was mapped using FT-NIR microscopy. Data were statistically analyzed according to the experimental design (α=0.05; ß=0.2). The radiant exposure in the violet wavelength range for Standard and Xtra-Power was 4.5 and 5.0 J/cm2, respectively; for the blue wavelength range the radiant exposure for Standard and Xtra-Power was 15.5 and 15.0 J/cm2, respectively. There was no statistical difference in the DOC using Standard or Xtra-Power light-curing modes, but the DOC was lower than the claimed by the manufacturer (4 mm). The DC was not significantly affected by the light-curing mode up to 4 mm in depth (p>0.05). According to exposure reciprocity law, the reduction in exposure time using the same radiant exposure did not affect the depth of cure of the bulk fill composite.

Resumo O objetivo deste estudo foi avaliar o efeito da lei de reciprocidade de um diodo emissor de luz (LED) multi-wave na transmitância de luz (LT), profundidade de cura (DOC) e grau de conversão em profundidade (DC) de um compósito bulk fill. Material e Métodos: Um compósito bulk fill (EvoCeram®, Ivoclar Vivadent) foi fotoativado utilizando um LED multi-wave (VALO ™ Cordless, Ultradent). O LED foi previamente caracterizado usando um espectrofotômetro para padronizar o tempo de exposição utilizando os modos Standard ou Xtra-Power com a mesma dose de energia de 20 J/cm 2. A LT foi avaliada através de amostras do compósito bulk fill a cada milímetro até 4 mm de profundidade. O DOC foi avaliado de acordo com a ISO 4049. O DC foi realizado em forma de mapeamento da seção transversal longitudinal central de cada amostra do teste de DOC utilizando microscopia FT-NIR. Os dados foram analisados estatisticamente de acordo com o delineamento experimental (α=0,05; ß=0,2). A exposição radiante na faixa de comprimento de onda violeta para os modos Standard e Xtra-Power foi de 4,5 e 5,0 J/cm2, respectivamente; e para a faixa de comprimento de onda azul, a exposição radiante para os modos Standard e Xtra-Power foi de 15,5 e 15,0 J/cm2, respectivamente. Não houve diferença estatística no DOC utilizando os modos de fotopolimerização Standard ou Xtra-Power, mas o DOC foi menor do que o reivindicado pelo fabricante (4 mm). O DC não foi afetado significativamente pelo modo de fotopolimerização até 4 mm de profundidade (p>0,05). De acordo com a lei de reciprocidade da exposição, a redução no tempo de exposição utilizando a mesma exposição radiante não afetou a profundidade de cura do compósito bulk fill.

Tubeimoside-1 induces TFEB-dependent lysosomal degradation of PD-L1 and promotes antitumor immunity by targeting mTOR

Programmed cell death ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) cascade is an effective therapeutic target for immune checkpoint blockade (ICB) therapy. Targeting PD-L1/PD-1 axis by small-molecule drug is an attractive approach to enhance antitumor immunity. Using flow cytometry-based assay, we identify tubeimoside-1 (TBM-1) as a promising antitumor immune modulator that negatively regulates PD-L1 level. TBM-1 disrupts PD-1/PD-L1 interaction and enhances the cytotoxicity of T cells toward cancer cells through decreasing the abundance of PD-L1. Furthermore, TBM-1 exerts its antitumor effect in mice bearing Lewis lung carcinoma (LLC) and B16 melanoma tumor xenograft

Analgesic effect and central mechanisms of CQ prescription on cancer invasion induced mirror image pain in model mice / 中国中药杂志

This study aimed to analyze the analgesic effect and related central mechanisms of CQ prescription on cancer invasion induced mirror image pain (CIIMIP)in model mice.In the study, male BALB/c mice were randomly divided into normal group, operation control group (injected with 0.2 mL inactivated S180 sarcoma cell sap), model group (injected with 0.2 mL S180 sarcoma cell sap on the right leg near the greater trochanter of femur) and CQ prescription low dose group (intraperitoneally injected with CQ prescription 100 mg•kg⁻¹ on the basis of model mice), CQ prescription middle dose group (intraperitoneally injected with CQ prescription 150 mg•kg⁻¹ on the basis of model mice), and CQ prescription high dose group (intraperitoneally injected with CQ prescription 200 mg•kg⁻¹ on the basis of model mice). Mechanical withdraw threshold (MWT) of the mirror image lateral hind paws were evaluated by Von Frey hairs before modeling and after surgery. The levels of glutamate (Glu), gamma aminobutyric acid (GABA), glycine (Gly), and taurine (Tau) in the L3-L5 spinal cord were measured by the high performance liquid chromatography-fluorescence detector (HPLC-FLD); AimPlex detection technology with multiple factors was used to detect the levels of regulated on activation in normal T-cell expressed and secreted (RANTES), monocyte chemoattractant protein (MCP-3) in the L3-L5 spinal cord. Then we observed the influence of GABAa receptor antagonist (Bicuculline) on analgesic effect of CQ prescription.The results indicated that CQ prescription could remarkably increase MWT of model mice(P<0.01, P<0.05), decrease the level of Glu(P<0.01, P<0.05), improve the levels of GABA, Gly, Tau(P<0.01, P<0.05), lower the ratio of Glu/GABA(P<0.01, P<0.05), and reduce the levels of RANTES, MCP-3(P<0.05) in the L3-L5 spinal cord, and GABAa receptor antagonist significantly blocked the analgesic effect of CQ prescription at two time points(P<0.05).This study showed that CQ prescription had significant analgesic effect on CIIMIP model mice, and its mechanism was associated with regulating the balance between excitability amino acid(EAA) and inhibitory amino acid (IAA) transmitters in central nervous system, partially activating GABAa receptor, and reducing the release of RANTES and MCP-3 in the spinal cord.

Effect of CQ-amine ratio on the degree of conversion in resin monomers with binary and ternary photoinitiation systems

OBJECTIVES: This study evaluated the effect of camphorquinone (CQ)-amine ratio on the C=C double bond conversion of resins with binary and ternary photoinitiation systems. MATERIALS AND METHODS: Two monomer mixtures (37.5 Bis-GMA/37.5 Bis-EMA/25 TEGDMA) with binary systems (CQ/DMAEMA in weight ratio, group A [0.5/1.0] and B [1.0/0.5]) and four mixtures with ternary system (CQ/OPPI/DMAEMA, group C [0.1/1.0/0.1], D [0.1/1.0/0.2], E [0.2/1.0/0.1] and F [0.2/1.0/0.2]) were tested: 1 : 2 or 2 : 1 CQ-amine ratio in binary system, while 1 : 1 ratio was added in ternary system. The monomer mixture was cured for 5, 20, 40, and 300 sec with a Demetron 400 curing unit (Demetron). After each exposure time, degree of conversion (DC) was estimated using Fourier transform infrared (FTIR) spectrophotometer (Nicolet 520, Nicolet Instrument Corp.). The results were analyzed by ANOVA followed by Scheffe test, with p = 0.05 as the level of significance. RESULTS: DC (%) was expressed in the order of curing time (5, 20, 40, and 300 sec). Group A (14.63 +/- 10.42, 25.23 +/- 6.32, 51.62 +/- 2.69, 68.52 +/- 2.77); Group B (4.04 +/- 6.23, 16.56 +/- 3.38, 37.95 +/- 2.79, 64.48 +/- 1.21); Group C (16.87 +/- 5.72, 55.47 +/- 2.75, 60.83 +/- 2.07, 68.32 +/- 3.31); Group D (23.77 +/- 1.64, 61.05 +/- 1.82, 65.13 +/- 2.09, 71.87 +/- 1.17); Group E (28.66 +/- 2.92, 56.68 +/- 1.33, 60.66 +/- 1.17, 68.78 +/- 1.30); Group F (39.74 +/- 6.31, 61.07 +/- 2.58, 64.22 +/- 2.29, 69.94 +/- 2.15). CONCLUSION: All the monomers with ternary photoinitiation system showed higher DC than the ones with binary system, until 40 sec. Concerning about the effect of CQ-amine ratio on the DC, group A converted into polymer more than group B in binary system. However, there was no significant difference among groups with ternary system, except group C when cured for 5 sec only.

Optical characteristics of resin composite before and after polymerization / 대한치과보존학회지

OBJECTIVES: The aim of this study was to evaluate the optical characteristics such as color and translucency changes before and after light curing, to quantify the CQ and to measure refractive indices of body and opaque shade of resin composites materials. MATERIALS AND METHODS: Resin composites used in this study were A2 body and A2 opaque shade of Esthet-X, Filtek supreme, Gradia Direct, Clearfil Majesty and Beautifil?? Color and translucency changes before and after light curing were evaluated by colorimeter, the CQ was quantified by GC-MS and refractive index changes were measured by spectroscopic ellipsometer. RESULTS: Translucency parameter (TP) was significantly increased after curing. The CQ content of body shades are higher than that of opaque shades in all resin composites. Refractive index increased after polymerization in all materials and significant difference in Deltarefractive index was found between body and opaque shade (significance level 0.05). CONCLUSIONS: For an accurate shade match, direct shade matching of resin composite should be performed by using the cured material.