Alterations to Titanium Surface Depending on the Fluorides and Abrasives in Toothpaste

Fluoride and abrasives in toothpastes may cause corrosion and deterioration of the titanium used for implants and other prostheses. The purpose of this study was to investigate how the presence or absence and types of fluoride and abrasives affected the titanium surface texture. Brushing with toothpastes was performed on pure-titanium discs using an abrasive testing machine. Unprocessed titanium discs without brushing were used as control samples. Surface roughness, color, and gloss of titanium were measured and the differences compared with the control were analyzed. Additionally, titanium surfaces and abrasives in toothpastes were observed using a scanning electron microscope to compare the surface texture of each sample. Some toothpastes (abrasive+) significantly increased the difference in surface roughness, color, and gloss, compared with ultrapure water. Toothpaste (fluoride+/abrasive+) that had many polygonal abrasive particles led to the largest color differences and exhibited notable scratches and a larger number of contaminant- or corrosion-like black spots. In contrast, brushing with toothpaste without fluoride or abrasives (fluoride−/abrasive−) caused little change to the titanium surface. These results suggest that both fluoride and abrasives in toothpaste used for brushing may be factors that affect surface texture and corrosion resistance of titanium.     

Chronic kidney disease stage stratifies short- and long-term outcomes after aortic root replacement

OBJECTIVESChronic kidney disease (CKD) is prevalent in patients undergoing cardiovascular surgery, and it negatively impacts procedural outcomes; however, its influence on the outcomes of aortic surgery has not been well studied. This study aims to elucidate the importance of CKD on the outcomes of aortic root replacement (ARR).Open in a separate windowMETHODSPatients who underwent ARR between 2005 and 2019 were retrospectively reviewed (n = 882). Patients were divided into 3 groups based on the Kidney Disease: Improving Global Outcomes criteria: Group 1 [estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73 m², n = 421); Group 2 (eGFR = 30–59 ml/min/1.73 m², n = 424); and Group 3 (eGFR < 30 ml/min/1.73 m², n = 37). To reduce potential confounding, a propensity score matching was also performed between Group 1 and the combined group of Group 2 and Group 3. The primary end point was 10-year survival. Secondary end points were in-hospital mortality and perioperative morbidity.RESULTSSevere CKD patients presented with more advanced overall chronic and acute illnesses. Kaplan–Meier analysis showed a significant correlation between CKD stage and 10-year survival (log-rank P < 0.001). The number of events for Group 1 was 15, Group 2 was 49 and Group 3 was 11 in 10 years. Group 3 had significantly higher in-hospital mortality (13.5% vs 3.5% in Group 2 vs 0.7% in Group 1, P < 0.001) and stroke (8.1% vs 7.1% vs 1.2%, P < 0.001) as well as introduction to new dialysis (27.0% vs 5.4% vs 1.7%, P < 0.001). eGFR was shown to be an independent predictor of mortality (hazard ratio, 0.98; 95% confidence interval, 0.96–0.99). Comparison between propensity matched groups showed similar postoperative outcomes, and eGFR was still identified as a predictor of mortality (hazard ratio, 0.97; 95% confidence interval, 0.95–0.99).CONCLUSIONSHigher stage in CKD negatively impacts the long-term survival in patients who are undergoing ARR.     

Natural killing activities in chronic liver diseases and hepatocellular carcinoma

Previously we proposed a new analysis of natural killing activity, for comparison, employing an individual effector/ target cell ratio according to the peripheral number of effector cells. Using this analysis, we studied natural killing activities in chronic liver diseases and hepatocellular carcinoma (HCC). The activity in chronic persistent hepatitis remained nearly at the level of the nonactivated state, but that was significantly elevated in chronic active hepatitis. The activity in liver cirrhosis (LC) of Child's A or B grade was at the level of a nonactivated or reduced-activity state, while LC patients with impaired general conditions showed significantly elevated activities. In HCC, each of which was accompanied by LC in our cases, the activity appeared to be associated with the progression of HCC. Thus, natural killing activity showed a close relationship with the condition of chronic liver diseases.     

Bond strength of adhesive resin to three nickel-chromium alloys with varying chromium content

This in vitro study evaluated the influence of chromium content on bond strength and durability between nickel-chromium alloys and an adhesive resin that contained 4-methacryloxyethyl trimellitate anhydride. Three nickel-chromium alloys with different chromium content, as well as pure chromium and pure nickel metals, were bonded and tested for shear strength. After repeated thermocycling, shear bond strength decrease was lower in alloys containing high chromium content. Pure chromium metal demonstrated a 15.2% decrease, whereas pure nickel metal demonstrated the greatest (53.7%) decrease. The results suggest that nickel-chromium alloys with higher chromium content are desirable for 4-methacryloxyethyl trimellitate anhydride resin-bonded restorations.     

Long-term survival after resection of mass-forming type intrahepatic cholangiocarcinoma directly infiltrating the transverse colon and sequential brain metastasis: Report of a case

MUC1 expression in cholangiocarcinoma is considered to be correlated with patient survival. We report a case of mass-forming type intrahepatic cholangiocarcinoma (ICC) with direct infiltration of the transverse colon and sequential brain metastasis. The patient was treated by curative right hepatectomy with right hemicolectomy followed by resection of the brain metastasis; there has been no evidence of recurrence in the 7 years since the hepatic resection. Thus, surgical resection may improve the prognosis of ICC involving the adjacent organs, even with brain metastasis. Immunohistochemical staining was performed for MUC1, MUC2, and MUC5AC. Although MUC1 expression was found in the liver tumor and metastatic brain tumor, the correlation between MUC1 expression and the prognosis of this patient was unclear. To clarify the correlation between immunohistochemical characteristics and prognosis, further studies on a greater number of cases of long-term survival of mass-forming type ICC are needed.