Clinical observation of autologous platelet rich fibrin assisted revascularization of mature permanent teeth.

OBJECTIVE: To investigate the clinical observation of autologous platelet-rich fibrin (PRF) assisting the revascularization of mature permanent teeth. METHODS: Twenty patients with mature permanent teeth were divided into experimental group and control group. The control group was treated with classic revascularization, and the experimental group was treated with PRF-assisted mature permanent tooth revascularization. RESULTS: After treatment, the total effective rate of the experimental group (100.00%) was higher than that of the control group (50.00%); the thickness of the root canal wall of the experimental group was higher than that of the control group, and the crown root length was lower than that of the control group; The bite degree, chewing function, color, overall aesthetic score, and satisfaction rate of the patients were higher, and the difference was statistically significant (P < 0.05). CONCLUSION: Autologous PRF assists in revascularization of mature permanent teeth, which can achieve ideal results, and promote pulp regeneration.

Cr(VI) immobilization in soil using lignin hydrogel supported nZVI: Immobilization mechanisms and long-term simulation.

A novel nanocomposite, named as nZVI@LH, was prepared by nanoscale zero-valent iron (nZVI) supported on lignin hydrogel and was used in the remediation of Cr(VI)-contaminated soil collected from an industrial site. Meanwhile, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and X-ray diffractometry (XRD) results determined that nZVI nanoparticles disperse uniformly on hydrogel. After the 14 days remediation, the immobilization efficiency of Cr(VI) could reach over 87% in the treatment of 3% (w/w%) nZVI@LH and 26% in the treatment of bare-nZVI. Leaching experiment results showed that the treatment group with 3% (w/w%) nZVI@LH was up to the national leaching toxicity identification standard, and there was no threat in simulation of acid rain over the long term. The water-soluble (WS) fraction in 3# nZVI@LH treatment decreased 31.1%, while the Fe-Mn oxide bound (OX) fraction and organic matter-bound (OM) fraction increased 10.9% and 13.4%, respectively. Moreover, nZVI@LH had limited impact on soil properties and the capability to immobilize Cr over a long period exposure to acid rain. This work prove that nZVI@LH has the potential to remediate Cr contaminated soil. Furthermore, details of possible mechanistic insight into the Cr remediation were carefully discussed.

[Effects of tooth whitening agents and acidic drinks on the surface properties of dental enamel].

OBJECTIVE: Using tooth whitening agents (bleaching clip) in vitro and acidic drinks, we conducted a comparative study of the changes in enamel surface morphology, Ca/P content, and hardness. METHODS: Tooth whitening glue pieces, cola, and orange juice were used to soak teeth in artificial saliva in vitro. Physiological saline was used as a control treatment. The morphology of the four groups was observed under a scanning electron microscope (SEM) immediately after the teeth were soaked for 7 and 14 d. The changes in Ca/P content and microhardness were analyzed. RESULTS: The enamel surfaces of the teeth in the three test groups were demineralized. The Ca/P ratio and the average microhardness were significantly lower than those of the control group immediately after the teeth were soaked (P < 0.05). The Ca/P ratio and microhardness gradually increased after 7 d. No significant difference was observed between the control group and the test groups after 14 d (P > 0.05). CONCLUSION: Bleaching agents caused transient demineralization of human enamel, but these agents could induce re-mineralization and repair of enamel over time. Demineralization caused by bleaching covered a relatively normal range compared with acidic drinks and daily drinking.