Bulk-fill composite resin are simple to operate, and they reduce polymerization shrinkage and microleakage compare to traditional resin-based composites. However, their clinical application could be affected by numerous factors, such as the material itself, light curing, placement techniques, storage condition, and preheating. This review aimed to summarize the definitions, classifications, indications, clinical properties, and influencing factors of the clinical application of bulk-fill resin-based composites and discuss the ways to improve their clinical effectiveness.
Composite Resins ; Dental Materials ; Materials Testing ; Polymerization ; Surface Properties

The restorative procedure in posterior teeth involves clinical steps related to professional skill, especially when using the incremental technique, which may fail in the long term. A recent alternative is bulk-fill resins, which can reduce polymerization shrinkage, decreasing clinical problems such as marginal leakage, secondary caries, and fracture. This scientific study aims to report a clinical case using bulk-fill resin with an occlusal matrix. As determined in the treatment plan, an acrylic resin matrix was produced to establish an improved oral and aesthetic rehabilitation of the right mandibular first molar, which presented a carious lesion with dentin involvement. The occlusal matrix is a simple technique that maintains the original dental anatomy, showing satisfactory results regarding function and aesthetic rehabilitation.
Composite Resins ; Dental Caries ; Dentin ; Esthetics ; Molar ; Polymerization ; Polymers ; Rehabilitation ; Tooth

In patients with fully edentulous jaw, treatment of complete dentures should be carried out in many stages when following the conventional methods. Therefore there were disadvantages such as multiple visits to dental clinic is inevitable. In addition, errors caused by polymerization shrinkage, which happens during the fabrication of denture, and difficulties in reproduction of damaged or lost denture were considered as disadvantages. But nowadays, computer-aided design and computer-aided manufacturing (CAD/CAM) system is widely used in dentistry and it has begun to expand its spectrum in manufacturing complete dentures. Using CAD/CAM system to fabricate complete dentures can reduce the number of patient's visit and clinical chair time, since taking impression, recording jaw relation, and selection of artificial teeth are performed at the same time during the first visit, and delivering of dentures during the second visit is possible. In addition, because 3D-Printing technology is used, errors by polymerization shrinkage can be reduced. Among the companies that fabricate complete dentures using CAD/CAM system, DENTCA CAD/CAM denture (DENTCA Inc., Los Angeles, CA, USA) is the most commercialized company. In this case, we treated patients of complete dentures using conventional complete denture method and DENTCA CAD/CAM denture system in the same patient. We would like to report this case because we have achieved good results not only in functional aspects of pronunciation, chewing, and swallowing but also in aesthetic aspects.
Computer-Aided Design ; Deglutition ; Dental Clinics ; Dentistry ; Denture, Complete ; Dentures ; Humans ; Jaw ; Jaw, Edentulous ; Mastication ; Methods ; Polymerization ; Polymers ; Reproduction ; Tooth, Artificial

To determine the chemopreventive potential of alyssin and iberin, the in vitro anticancer activities and molecular targets of isothiocyanates (ITCs) were measured and compared to sulforaphane in hepatocellular carcinoma cell HepG2. The SR-FTIR spectra observed a similar pattern vis-à-vis the biomolecular alteration amongst the ITCs-treated cells suggesting a similar mode of action. All of the ITCs in this study cause cancer cell death through both apoptosis and necrosis in concentration dependent manner (20–80 μM). We found no interactions of any of the ITCs studied with DNA. Notwithstanding, all of the ITCs studied increased intracellular reactive oxygen species (ROS) and suppressed tubulin polymerization, which led to cell-cycle arrest in the S and G₂/M phase. Alyssin possessed the most potent anticancer ability; possibly due to its ability to increase intracellular ROS rather than tubulin depolymerization. Nevertheless, the structural influence of alkyl chain length on anticancer capabilities of ITCs remains inconclusive. The results of this study indicate an optional, potent ITC (viz., alyssin) because of its underlying mechanisms against hepatic cancer. As a consequence, further selection and development of effective chemotherapeutic ITCs is recommended.
Apoptosis ; Carcinoma, Hepatocellular ; Cell Death ; DNA ; In Vitro Techniques ; Isothiocyanates ; Liver Neoplasms ; Necrosis ; Polymerization ; Polymers ; Reactive Oxygen Species ; Tubulin ; Vegetables

Conventional dental resins for crown and bridge fulfill ISO 10477 and ISO 10993 before clinical application. Although 3D printing or rapid prototyping (RP) for the fabrication of temporary crown and bridge have been proposed, a little studies were reported for 3D printing resin for temporary crown and bridge. The purpose of this study was to evaluate the physical properties (such as water sorption and solubility, color stability and flexural strength) of the various 3D printing temporary crown and bridge resin following the ISO 10477:2018 and estimate the effect of chemical composition of resin on the physical properties. Four resins approved by KFDA and 4 experimental resins developed by different manufacturer were tested in this study. Samples were prepared with DLP typed 3D Printer (G-Printer) and post-cured using UV-light Cure Unit (Cure M). Proper 3D printing and post-curing conditions were selected for different 3D printing resins. Each test was performed according to the ISO 10477 and results were statistically analyzed using Tukey-multiple comparison test (p=0.05). Only group-B did not satisfied the ISO requirement (< 40 µg/ mm³) in water sorption test, but 3 groups (C, E and F) showed high solubility which exceeds the ISO requirement (< 7.5 µg/mm³). For color stability, the color difference were detected at 5 groups (A, E, F, G and H). Group-D and F showed the low flexural strength and some building direction did not satisfied the ISO requirement (> 60 MPa). Resin components may affect the flexural strength, then user should check the components of 3D printing resin. Deficient degree of polymerization may lead to large water sorption, water solubility and color changes. Further study should be done comparison between specimens printed with specific 3D printer recommended by manufacturer and specimens used in this study.
Crowns ; Polymerization ; Polymers ; Printing, Three-Dimensional ; Resins, Synthetic ; Solubility ; Water

OBJECTIVES: The aim of this study was to evaluate the influence of different concentrations of nanofillers on the chemical and physical properties of ethanol-solvated and non-solvated dental adhesives. MATERIALS AND METHODS: Eight experimental adhesives were prepared with different nanofiller concentrations (0, 1, 2, and 4 wt%) and 2 solvent concentrations (0% and 10% ethanol). Several properties of the experimental adhesives were evaluated, such as water sorption and solubility (n = 5, 20 seconds light activation), real-time degree of conversion (DC; n = 3, 20 and 40 seconds light activation), and stability of cohesive strength at 6 months (CS; n = 20, 20 seconds light activation) using the microtensile test. A light-emitting diode (Bluephase 20i, Ivoclar Vivadent) with an average light emittance of 1,200 mW/cm2 was used. RESULTS: The presence of solvent reduced the DC after 20 seconds of curing, but increased the final DC, water sorption, and solubility of the adhesives. Storage in water reduced the strength of the adhesives. The addition of 1 wt% and 2 wt% nanofillers increased the polymerization rate of the adhesives. CONCLUSIONS: The presence of nanofillers and ethanol improved the final DC, although the DC of the solvated adhesives at 20 seconds was lower than that of the non-solvated adhesives. The presence of ethanol reduced the strength of the adhesives and increased their water sorption and solubility. However, nanofillers did not affect the water sorption and strength of the tested adhesives.
Adhesives ; Dental Cements ; Ethanol ; Longevity ; Polymerization ; Polymers ; Solubility ; Solvents ; Water

BACKGROUND: Light-emitting diodes curing unit (LCU), which emit blue light, is used for polymerization of composite resins in many dentistry. Although the use of LCU for light-cured composite resin polymerization is considered safe, it is still controversial whether it can directly or indirectly have harmful biological influences on oral tissues. The aim of this study was to elucidate the biological effects of LCU in wavelengths ranging from 440 to 490 nm, on the cell viability and secretion of inflammatory cytokines in MDPC-23 odontoblastic cells and inflammatory-induced MDPC-23 cells by lipopolysaccharide (LPS). METHODS: The MTT assay and observation using microscope were performed on MDPC-23 cells to investigate the cell viability and cytotoxic effects on LCU irradiation. RESULTS: MDPC-23 cells and LPS stimulated MDPC-23 cells were found to have no effects on cell viability and cell morphology in the LCU irradiation. Nitric oxide (NO) and prostaglandin E2 which are the pro-inflammatory mediators, and interleukin-1β and tumor necrosis factor-α (TNF-α) which are the proinflammatory cytokines were significantly increased in MCPD-23 cells after LCU irradiation as time increased in comparison with the control. LCU irradiation has the potential to induce inflammation or biological damages in normal dental tissues, including MDPC-23 cells. CONCLUSION: Therefore, it is necessary to limit the use of LCU except for the appropriate dose and irradiation time. In addition, LCU irradiation of inflammatory-induced MDPC-23 cells by LPS was reduced the secretion of NO compared to the LPS alone treatment group and was significantly reduced the secretion of TNF-α in all the time groups. Therefore, LCU application in LPS stimulated MDPC-23 odontoblastic cells has a photodynamic therapy like effect as well as inflammation relief.
Cell Survival ; Composite Resins ; Cytokines ; Dentistry ; Dinoprostone ; Inflammation ; Necrosis ; Nitric Oxide ; Odontoblasts ; Photochemotherapy ; Polymerization ; Polymers

BACKGROUND: The light-emitting diode (LED) curing light used is presumed to be safe. However, the scientific basis for this is unclear, and the safety of LED curing light is still controversial. The purpose of this study was to investigate the effect of LED curing light irradiation according to the conditions applied for the polymerization of composite resins in dental clinic on the cell viability and inflammatory response in Raw264.7 macrophages and to confirm the stability of LED curing light. METHODS: Cell viability and cell morphology of Raw264.7 macrophages treated with 100 ng/ml of lipopolysaccharide (LPS) or/and LED curing light with a wavelength of 440~490 nm for 20 seconds were confirmed by methylthiazolydiphenyl-tetrazolium bromide assay and microscopic observation. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) was confirmed by NO assay and PGE2 enzyme-linked immunosorbent assay kit. Expression of interleukin (IL)-1β and tumor necrosis factor (TNF)-α in total RNA and protein was confirmed by reverse transcription polymerase chain reaction and Western blot analysis. RESULTS: The LED curing light did not affect the viability and morphology of normal Raw264.7 cells but affected the cell viability and induced cytotoxicity in the inflammation-induced Raw264.7 cells by LPS. The irradiation of the LED curing light did not progress to the inflammatory state in the inflammation-induced Raw264.7 macrophage. However, LED curing light irradiation in normal Raw264.7 cells induced an increase in NO and PGE2 production and mRNA and protein expression of IL-1β and TNF-α, indicating that it is possible to induce the inflammatory state. CONCLUSION: The irradiation of LED curing light in RAW264.7 macrophage may induce an excessive inflammatory reaction and damage oral tissues. Therefore, it is necessary to limit the long-term irradiation which is inappropriate when applying LED curing light in a dental clinic.
Blotting, Western ; Cell Survival ; Composite Resins ; Dental Clinics ; Dinoprostone ; Enzyme-Linked Immunosorbent Assay ; Interleukins ; Macrophages ; Nitric Oxide ; Polymerase Chain Reaction ; Polymerization ; Polymers ; Reverse Transcription ; RNA ; RNA, Messenger ; Tumor Necrosis Factor-alpha

BACKGROUND: Mesenchymal stem cells (MSCs) have strong self-renewal ability and multiple differentiation potential. Some studies confirmed that spreading shape and area of single MSCs influence cell differentiation, but few studies focused on the effect of the circularity of cell shape on the osteogenic differentiation of MSCs with a confined area during osteogenic process.METHODS: In the present study, MSCs were seeded on a micropatterned island with a spreading area lower than that of a freely spreading area. The patterns had circularities of 1.0 or 0.4, respectively, and areas of 314, 628, or 1256 µm² . After the cells were grown on a micropatterned surface for 1 or 3 days, cell apoptosis and F-actin were stained and analyzed. In addition, the expression of β-catenin and three osteogenic differentiation markers were immunofluorescently stained and analyzed, respectively.RESULTS: Of these MSCs, the ones with star-like shapes and large areas promoted the expression of osteogenic differentiation markers and the survival of cells. The expression of F-actin and its cytosolic distribution or orientation also correlated with the spreading shape and area. When actin polymerization was inhibited by cytochalasin D, the shape-regulated differentiation and apoptosis of MSCs with the confined spreading area were abolished.CONCLUSION: This study demonstrated that a spreading shape of low circularity and a larger spreading area are beneficial to the survival and osteogenic differentiation of individual MSCs, which may be regulated through the cytosolic expression and distribution of F-actin.
Actins ; Antigens, Differentiation ; Apoptosis ; Cell Differentiation ; Cell Shape ; Cytochalasin D ; Cytosol ; Mesenchymal Stromal Cells ; Osteogenesis ; Polymerization ; Polymers

This study aimed to determine whether the curing times of Xtra Power and High Power modes of high-power light emitting diode (LED) curing light are sufficient for polymerization of resin sealants. The specimens were prepared and their microhardness values were measured and compared with those of specimens polymerized under conventional LED curing light.The filled sealant polymerized for 8 seconds in the High Power mode and for 3 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000). The unfilled sealant polymerized for 8, 12 seconds in the High Power mode and for 6 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000).The results of this study suggest that the short curing time with the Xtra Power and High Power modes of highpower LED curing light are not sufficient for adequate polymerization of sealants under specific conditions, taking into account the curing times and the type of sealant.
Polymerization ; Polymers