ABSTRACT
The combinations of alumina particle air abrasion (AA) and a 10-methacryloyloxyidecyl-dihyidrogenphosphate (MDP) primer and a tribochemical silica coating (TSC) and a silane-base primer are contemporary pre-cementation treatments for zirconia restorations for bonding with resin cements. However, the stability of zirconia resists the mechanical or chemical preparations. The purpose of this study was to develop an atmospheric-pressure oxygen plasma (OP)-aided silicatization method to enhance the adhesion of resin cements to zirconia. Zirconia discs were prepared to receive surface treatments of different combinations: (1) AA or TSC (2) with or without OP treatment, and (3) a chemical primer (no primer, silane, or a silane-MDP mixture). The surface morphology, hydrophilicity, and chemical compositions were characterized, and the resin-zirconia bond strengths were examined either after 24 h or a thermocycling test. The results indicated that the OP treatment after the TSC facilitated the homogeneous distribution of silane and crosslinking of silica particles, and effectively improved the hydrophilicity. The OP increased the O and Si and reduced the C elemental contents, while the combination of TSC, OP, and silane induced SiOx generation. Among the groups, only the TSC-OP-silane treatment effectively enhanced the bond strength and maintained the adhesion after thermocycling. With these results, the OP aided the silicatization protocol effectively, generated silane crosslinking, and resulted in superior resin-zirconia bond strength and durability compared to the current treatments.
ABSTRACT
Blue light (BL) curing on dental resin composites results in gradient polymerization. By incorporating upconversion phosphors (UP) in resin composites, near-infrared (NIR) irradiation may activate internal blue emission and a polymerization reaction. This study was aimed to evaluate the competency of the NIR-to-BL upconversion luminance in polymerizing dental composites and to assess the appropriate UP content and curing protocol. NaYF4 (Yb3+/Tm3+ co-doped) powder exhibiting 476-nm blue emission under 980-nm NIR was adapted and ball-milled for 4-8 h to obtain different particles. The bare particles were assessed for their emission intensities, and also added into a base composite Z100 (3M EPSE) to evaluate their ability in enhancing polymerization under NIR irradiation. Experimental composites were prepared by dispensing the selected powder and Z100 at different ratios (0, 5, 10 wt% UP). These composites were irradiated under different protocols (BL, NIR, or their combinations), and the microhardness at the irradiated surface and different depths were determined. The results showed that unground UP (d50 = 1.9 µm) exhibited the highest luminescence, while the incorporation of 0.4-µm particles obtained the highest microhardness. The combined 20-s BL and 20-120-s NIR significantly increased the microhardness on the surface and internal depths compared to BL correspondents. The 5% UP effectively enhanced the microhardness under 80-s NIR irradiation but was surpassed by 10% UP with longer NIR irradiation. The combined BL-NIR curing could be an effective approach to polymerize dental composites, while the intensity of upconversion luminescence was related to specific UP particle size and content. Incorporation of 5-10% UP facilitates NIR upconversion polymerization on dental composites.
ABSTRACT
OBJECTIVE: To evaluate the expression level of LKB1 gene in patients with acute lymphoblastic leukemia (ALL), and analyze its correlation with illness condition of patients. METHODS: The 98 patients with leukemia in our hospital were divided into two groups according to the diagnosis of patients: ALL group (56 cases) and ANLL group (42 cases). The 50 healthy persons subjected to physical examination were selected as control group. The peripheral blood mononuclear cells (PBMNC) were separated from the venous blood samples of three groups, and the expression levels of LKB1 gene were detected by RT-PCR and were compared among three groups. Patients in ALL group were divided into two groups according to the expression level of LKB1 gene: low expression group (39 cases) and high expression group (17 cases). Follow-up 3 years, the curves of OS and DFS in two groups were gained by Kaplan-Meier analysis. The ratios of CR and recurrence were compared between two groups. The related risk factors (all P<0.05) influencing the survival of patients with ALL were confirmed by multivariate logistic analysis. RESULTS: The expression level of LKB1 gene of control group was 1.56(1.38-1.74)>ALL group 1.32(1.22-1.40)>ANLL group 0.89(0.78-1.02). There were statistical differences among the three groups (all P<0.05). Compared with low expression group, the CR rate in high expression group were higher, but the recurrence rate were lower in high expression group (all P<0.05). Follow-up 3 years, the OS and DFS rates in high expression group were higher than those in low expression group (all P<0.05). There was negative relation between expression level of LKB1 gene and clinical risk level of ALL patients (r=-0.712, P=0.039). For standard risk ALL, the patients in LKB1 low expression group was significantey lower than that in high expression group; and for high risk ALL, the patients in LKB1 low expression group was significant higher than that in high expression group. Multivariate logistic analysis showed that the age (OR=2.872, P=0.020), peripheral blood immature cell count (OR=2.268, P=0.028) were independent risk factors for survival of patients with ALL, and the expression level of LKB1 gene (OR=0.426, P=0.016) is protective factor. CONCLUSION: The expression level of LKB1 gene in patients with ALL is low, moreover the more low expression level of LKB1 gene were, the more severe ill condition and more poor prognosis were.
