[Clinical application of optimal designed Upcera super transparent zirconia all-ceramic restorations].

PURPOSE: To summarize the clinical application of special designed Upcera ST zirconia all-ceramic restorations in cases with limited occlusal space. METHODS: Twenty-one patients with 23-unit restorations were enrolled in this study. First, the shape of abutment teeth and diagnostic wax-up were captured and digitized by Sirona inEos system. Then, each individually shaped framework to grant a defined ST zirconia base core was created by the reduced program of inLab software. Finally, all restorations were veneered with VITA VM9 and evaluated at placement using modified U.S.Public Health Service Criteria 6 to 12 months after restoration. Patients were inquired with satisfaction questionnaire at the same time. RESULTS: During 6 to 12 months of follow-up visit, except for one of 23 restorations was rated as failure by fractured root, none was replaced due to framework fracture or unrestorable delamination of the ceramic veneer. The shape and colour of all restorations were satisfactory. CONCLUSIONS: To ensure optimum long-term clinical results of all-ceramic crown restorations, one important key is to overcome the fragmentation of dental prosthesis through modifying the shape of restoration. Based on the results of this study, the specially designed processing technology shows sufficient stability for ST zirconia all-ceramic restorations within a short term, which is deserved to be used in selected cases.

Study on the conformation changes of Lysozyme induced by Hypocrellin A: the mechanism investigation.

The interactions between Lysozyme and Hypocrellin A are investigated in details using time-resolved fluorescence, fourier transform infrared spectroscopy (FTIR), circular dichroism spectroscopy (CD), three-dimensional fluorescence spectra, and thermal gravimetric analysis (TGA) techniques. The results of time-resolved fluorescence suggest that the quenching mechanism is static quenching. FTIR and CD spectroscopy provide evidences of the reducing of α-helix after interaction. Hypocrellin A could change the micro-environmental of Lysozyme according to hydrophobic interaction between the aromatic ring and the hydrophobic amino acid residues, and the altered polypeptide backbone structures induce the reduction of α-helical structures. Moreover, TGA study further demonstrates the structure changes of Lysozyme on the effect of Hypocrellin A. This study could provide some important information for the derivatives of HA in pharmacy, pharmacology and biochemistry.

[Clinical evaluation of zirconia all-ceramic crowns and bridges designed and manufactured by computer aided design and computer aided manufacture system].

OBJECTIVE: To evaluate the clinical behavior of zirconia restorations fabricated by computer aided design and computer aided manufacture (CAD-CAM) system. METHODS: One hundred and thirteen patients with 167 unit restorations were enrolled in the study. First, the shape of abutment teeth and occlusion record was captured and digitized by Sirona inEos system. Then, each individually shaped framework was created using the cut-back program of inLab V3.85 software to leave a uniform thickness to the ceramic veneer. All restorations were veneered with Vita-VM9 and evaluated at baseline, 6, 12 months after delivery using the modified U S Public Health Service Criteria (USPHS). RESULTS: During the 6 to 12 months' follow-up visit, the success rate of the restorations was 96.1% (147/153), none was replaced due to framework fracture or unrestorable delamination of the ceramic veneer, and all patients were satisfied with the shape and color of their restorations. CONCLUSIONS: Based on the results of this study, it can be concluded that zirconia frameworks demonstrated sufficient stability for all-ceramic fixed partial denture using individual-design processing technology.

Improved biological performance of microarc-oxidized low-modulus Ti-24Nb-4Zr-7.9Sn alloy.

Ti-24Nb-4Zr-7.9Sn (TNZS) is a newly developed beta-titanium alloy with low modulus and it has been considered as good material for dental or orthopedic implant. The purpose of the current study is to evaluate the effect of micro-arc oxidation (MAO) treatment on the biological performance of TNZS surface. The phases, morphology and chemical composition of the MAO-treated surface were characterized by X-ray diffraction, energy dispersive spectroscope and scanning electron microscopy analysis respectively. Then we tested the biocompatibility by examining the cell morphology and viability of osteoblast cells growing on MAO-TNZS surface. The bone binding strength of the specimens was evaluated by removal torque test after implantation in rabbit tibiae for 6 weeks. Compared with the none-treated titanium and TNZS specimens, MAO treated TNZS specimens showed a significant increase (p<0.05) in hydrophilicity, roughness, cell viability and removal torque forces. In summary, MAO treatment helps to form a porous surface with a biologically active bone-like apatite layer on TNZS specimens, which may improve the biological response of MAO-TNZS implants.

[Experimental study of Ti-24Nb-4Zr-7.9Sn alloy after treated with micro-arc oxidation in vivo].

OBJECTIVE: To study the biocompatibility of Ti-24Nb-4Zr-7.9Sn (TNZS) ahoy treated with micro-arc oxidation (MAO). METHODS: The tibia bones of New Zealand rabbits were used to build the animal model. TNZS and MAO-TNZS samples were implanted into one side of tibia, pure titanium samples were implanted into the other side as control. After 4 and 26 weeks, radiographs and HE staining technique was used to observe the dynamic remodeling process of bone-implant interface. RESULTS: As the cure time increased, it was showed well biocompatibility of all implants. X-ray indicated that there was no permeable area produced around the three different materials at each time point. The density of bone matrix and arrangement of bone trabecula was almost the same as in the host bone. It was revealed by histological examination that the MAO-TNZS greatly prompted the bonding ability between implant and surrounding hard tissues. Four weeks after implantation, fine attachment was found at the bone-implant interface of all the implants and the fibrous tissue at the interface was gradually remodeled to form new bone. Twenty-six weeks later, MAO-TNZS showed that a biological fixation was created between bone and oxidation layer, while a layer of fibers formed between non-coated TNZS and titanium implants surrounding bone. CONCLUSION: The Ti-24Nb-4Zr-7.9Sn after treated with micro-arc oxidation shows good biocompatibility and can stimulate the bone growth in the bone-implant region, which provides support for clinical usage tests of TNZS alloy as implant after treated with micro-arc oxidation.