The effect of magnesium oxide supplementation to aluminum oxide slip on the jointing of aluminum oxide bars

The purpose of this study was to investigate the effect of modifying aluminum oxide slips with magnesium oxide (MgO) tocreate a jointing material for In-CeramR Alumina. Jointed In-CeramR Alumina bars with In-CeramR Alumina slips containing0－1.0 mass％ MgO were examined by a three-point bending test. Joint-free bars were also tested as controls.Fracture surfaces were evaluated by scanning electron microscopy. In addition, linear shrinkage and fracture toughnesswere assessed.　　The 0.3 mass％ MgO group showed the highest flexural strength among the jointed groups, and there were no statisticaldifferences between the joint-free control groups. The fracture surface of 0.3 mass％ MgO group showed increasedsintering densification with reduced micropore size. No linear shrinkage was observed with the addition of MgO to thealumina slip. Added MgO was also effective in boosting fracture toughness. The present findings indicate that the MgOsupplementedbinding material is useful for clinical applications

Bone Formation Ability and Cell Viability Enhancement of MC3T3-E1 Cells by Ferrostatin-1 a Ferroptosis Inhibitor of Cancer Cells

Recently, ferroptosis has gained scientists’ attention as an iron-related regulated necrosis. However, not many reports have investigated the effect of ferroptosis on bone. Therefore, with the present study, we assessed the effect of ferroptosis inhibition using ferrostatin-1 on the MC3T3-E1 pre-osteoblast cell. Cell images, cell viability, alkaline phosphatase activity test, alizarin red staining, and RUNX2 gene expression using real-time PCR were applied to investigate the effects of ferrostatin and erastin on MC3T3-E1 osteoblast cells. Erastin was used as a well-known ferroptosis inducer reagent. Erastin with different concentrations ranging from 0 to 50 µmol/L was used for inducing cell death. The 25 µmol/L erastin led to controllable partial cell death on osteoblast cells. Ferrostatin-1 with 0 to 40 µmol/L was used for cell doping and cell death inhibition effect. Ferrostatin-1 also displayed a recovery effect on the samples, which had already received the partially artificial cell death by erastin. Cell differentiation, alizarin red staining, and RUNX2 gene expression confirmed the promotion of the bone formation ability effect of ferrostatin-1 on osteoblast cells. The objective of this study was to assess ferrostatin-1’s effect on the MC3T3-E1 osteoblast cell line based on its ferroptosis inhibitory property

Bone Formation Ability and Cell Viability Enhancement of MC3T3-E1 Cells by Ferrostatin-1 a Ferroptosis Inhibitor of Cancer Cells

Recently, ferroptosis has gained scientists’ attention as an iron-related regulated necrosis. However, not many reports have investigated the effect of ferroptosis on bone. Therefore, with the present study, we assessed the effect of ferroptosis inhibition using ferrostatin-1 on the MC3T3-E1 pre-osteoblast cell. Cell images, cell viability, alkaline phosphatase activity test, alizarin red staining, and RUNX2 gene expression using real-time PCR were applied to investigate the effects of ferrostatin and erastin on MC3T3-E1 osteoblast cells. Erastin was used as a well-known ferroptosis inducer reagent. Erastin with different concentrations ranging from 0 to 50 µmol/L was used for inducing cell death. The 25 µmol/L erastin led to controllable partial cell death on osteoblast cells. Ferrostatin-1 with 0 to 40 µmol/L was used for cell doping and cell death inhibition effect. Ferrostatin-1 also displayed a recovery effect on the samples, which had already received the partially artificial cell death by erastin. Cell differentiation, alizarin red staining, and RUNX2 gene expression confirmed the promotion of the bone formation ability effect of ferrostatin-1 on osteoblast cells. The objective of this study was to assess ferrostatin-1’s effect on the MC3T3-E1 osteoblast cell line based on its ferroptosis inhibitory property

Effect of polishing and finishing procedures on the surface integrity of restorative ceramics

PURPOSE: To investigate the effect of surface polishing and finishing methods on the surface roughness of restorative ceramics. METHODS: Disk specimens were prepared from feldspar-based, lithium disilicate-based, fluorapatite leucite-based and zirconia ceramics. Four kinds of surface polishing/finishing methods evaluated were: Group 1: Control: carborundum points (CP); Group 2: silicon points (SP); Group 3: diamond paste (DP); Group 4: glazing (GZ). Surface roughness was measured using an interferometer and the parameters of Sa (average height deviation of the surface) and St (maximum peak-to-valley height of the surface) were evaluated. Data were statistically analyzed using two-way ANOVA (P < 0.05) followed by post-hoc test. The mean values were also compared by Student's t-test. Specimen surfaces were evaluated by 3-D images using an interferometer. RESULTS: The zirconia showed the least surface roughness (Sa and St) values after grinding with carborundum points. The significantly lowest Sa values and St values were obtained for lithium disilicate and zirconia ceramics surfaces finished with DP and GZ. The fluorapatite leucite ceramic showed significantly reduced Sa and St values from DP to GZ. The feldspathic porcelain showed the highest surface roughness values among all types of ceramics after all of the polishing/finishing procedures

Effects of cleaning methods for custom abutment surfaces on gene expression of human gingival fibroblasts

The aim of this study was to develop an effective method for cleaning implant abutments made by computer-aided design and computer-aided manufacturing techniques and to investigate the effect of decontamination in vitro. Briefly, a newly developed reagent (PK) and/or vacuum plasma (Plasma) were used to clean the surfaces of zirconia disks, and the effects of this decontamination were evaluated by X-ray photoelectron spectroscopy. Human gingival fibroblasts (HGFs) were cultured on sample disks for 6, 24, and 48 h. We evaluated cell attachment and gene expression of the acute inflammatory cytokines interleukin-6 and vascular endothelial growth factor A, and type 1 collagen. In the PK and PK+Plasma groups, surface contaminants were reduced by washing. In addition, HGF attachments was increased in the PK and PK+Plasma groups. Gene expressions of interleukin-6 and vascular endothelial growth factor A were lower at 6 h. Gene expression of type 1 collagen was increased at all time points after seeding. These results suggest that decontamination of implant abutment surfaces is important in initial HGF attachment and may improve the biological seal of peri-implant soft tissue

Antibacterial Properties of Nano-Ag Coating on Healing Abutment: An In Vitro and Clinical Study

Peri-implantitis is an inflammatory disease with a relevant focus on the long-term success of dental implants and implant-supported prostheses. The present study focuses on the antibacterial effect of the silver nanoparticle and investigated the suppression of dental plaque adhesion on implant abutment and/or superstructure by micro-wave assistant nanosilver coating in vivo and in vitro. Nanosilver coating on pure titanium was prepared by microwave-assisted synthesis, and characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. In vitro studies were conducted to analyze biocompatibility using MTS assay and fluorescence microscopy with human gingival fibroblasts to evaluate antibacterial activity. During the in vivo study, nanosilver coating was applied to the healing abutments, and the prevention of plaque accumulation on nanosilver coating was confirmed by a split-mouth randomized clinical trial. The aggregation of nano-sized particles was found on the titanium surface with an antibacterial effect. The coating had no cytotoxic effect on human gingival fibroblasts. The result of the clinical trial showed that the coating suppressed the dental plaque adhesion on the healing abutments. Nanosilver coating is a promising material with antibacterial properties and can be used for implant abutments and prostheses for preventing peri-implantitis

Retrospective cohort study of rough-surface titanium implants with at least 25 years’ function

Abstract Background The longitudinal clinical outcomes over decades contribute to know potential factors leading to implant failure or complications and help in the decision of treatment alternatives. Methods The cases of all patients who received dental implants treated with titanium plasma-sprayed surfaces and whose prostheses were set in the period 1984–1990 at seven private practices were retrospectively analyzed. The cumulative survival rate, the cumulative incidence of peri-implantitis, and the complication-free prosthesis rate were calculated with Kaplan-Meier survival curves, and the factors’ influence on implant survival rate and the incidence of peri-implantitis were determined by a single factor in univariate analyses and multivariate analyses. Results A total of 223 implants and 106 prostheses were applied to 92 patients, and approx. 62% of the implants and patients dropped out over the 25 years following their treatment. The cumulative survival rates of the implants at 10, 15, and 25 years were 97.4, 95.4, and 89.8%, respectively. A significant difference was observed in the implant position. The cumulative incidences of peri-implantitis at 10, 15, and 25 years were 15.3, 21.0, and 27.9%, respectively. Significant differences were observed in the gender, implant type, and width of keratinized mucosa around the implant. The cumulative survival rates of mechanical complication-free prostheses at 10, 15, and 25 years were 74.9, 68.8, and 56.4%, respectively. The difference in the type of prosthesis resulted in significant differences. Conclusions The high rate of dropout during follow-up indicates the difficulty of determining long-term (> 25 years) prognoses. The gender, location, and width of keratinized mucosa affected the development of peri-implantitis, resulting in late failures. Implant-supported overdentures were frequently repaired. Tooth implant-supported prostheses are not recommended for long-term survival