BACKGROUND:As the latest generation of ultrahigh molecular weight polyethylene, vitamin E-stabilized ultrahigh molecular weight polyethylene has been widely put into use of various kinds of joint replacement. However, wear debris and osteolysis caused by that are stil the vital factor influencing the clinical curative effect. OBJECTIVE:To discuss and summarize the material characteristics and application progress of vitamin E-stabilized ultrahigh molecular weight polyethylene, and to seek the theoretical basis which can guide us to launch vitamin E-stabilized ultrahigh molecular weight polyethylene clinical y. METHODS:The first author retrieved the CNKI and Medline databases by computer. The keywords were“ultra-high molecular weight polyethylene, vitamin E-stabilized, joint replacement, application”in English. RESULTS AND CONCLUSION:Total y 92 articles were retrieved. According to the inclusion and exclusion criteria, 46 articles were included in result analysis. The results show that vitamin E-stabilized ultrahigh molecular weight polyethylene can not only enhance the physicochemical property of prosthesis, but also can integrate with free radicals to increase antioxidant rate of prothesis in order to prolong the long-term curative effect of prosthesis. However, it is stil lack of vast of clinical cases and fol ow-up as evidence. In case of that, long-term clinical efficacy remains to be assessed.

BACKGROUND: As a minimally invasive technology, percutaneous vertebroplasty is a safe and effective treatment for osteoporotic vertebral compression fractures.OBJECTIVE: To overview the research progress concerning the biomechanical properties, bone strength maintenance, bone absorption and degradation of bone filling materials used in percutaneous vertebroplasty.METHODS: The first author conducted a computer-based retrieval of CNKI, PubMed and Medline databases for relevant articles published from January 2005 to May 2016. The keywords were bone cement, bone filling materials, percutaneous vertebroplasty in English and Chinese, respectively.RESULTS AND CONCLUSION: Polymethyl methacrylate is not an ideal material for osteoporotic vertebral compression fractures. Calcium phosphate cement and calcium sulfate cement can replace the traditional polymethyl methacrylate; however, some problems still exist, such as poor effect of venography, incontrollable biological degradation rate, and lack of the evidence-based medicine about its long-term effect. Composite bone cement, as a good bone repair material, holds the advantages of various bone cements. As the composite bone cement has just been introduced in clinical practice, its long-term curative efficacy needs to be further studied.

Objective To investigate the treatment mechanism and effect of platelet-rich plasma(PRP) in treating rabbit knee osteoarthosis(KOA).Methods Thirty-two New Zealand adult clean class rabbits were randomly divided into the blank control group(A),model control group(B),PRP treatment group(C) and sodium hyaluronate treatment group(D).The group A conducted the simulated model construction,while the group B,C and D established the KOA rabbit model by using the Hulth method.After establishing the animal model,the group C was given PRP 0.5mLl by knee articular cavity injection,once every 3 weeks,twice in total;the group D was given sodium hyaluronate by knee articular cavity injection,once per week for 5 continuous weeks.The group A and B were injected with equal amount of normal saline at the same time point in the group C.The histological structure of articular cartilage,cell number,integrity of tidal line,and toluidine blue staining were observed by common optical microscope.The differences of Mankin′s scores were compared among various groups.The proper amount of knee joint fluid was collected for measuring the arachidonic acid expression in each group.Results The structure and morphology of articular cartilage in the group A were normal without obvious damage,while which in the group B,C and D had different degrees of damage,especially the cartilage structure in the group B had greater changes.Although the group B and C had the morphological and structure change of articular cartilage,but which was close to the cartilage structure in the group A.The Mankin′s score in the group A was lowest,while which in the group B was highest,which in the group C and D was significantly decreased after intervention treatment;the difference between the group B with the group C and D had statistical significance(P<0.05).The difference between the group C and D had statistical significance(P<0.05).The arachidonic acid level in the group A was lowest and which in the group B was highest,which in the group C and group D ranged between the group A and B,moreover the group C was lower than the group D (P<0.05).Conclusion PRP has obvious therapeutic and alleviated effect in treating KOA.

BACKGROUND:Platelet-rich plasma (PRP) containing high levels of platelet-derived growth factor for knee osteoarthritis has achieved good clinical results;however, the effects of RPR on the repair of damaged articular cartilage are stil controversial.
OBJECTIVE:To study the effects of RPR on the repair of damaged articular cartilage in a rabbit model of knee osteoarthritis.
METHODS:The model of osteoarthritis in the rabbit right knee was established by Hulth’s method. Autologous PRP (0.5 mL) (PRP group), sodium hyaluronate (0.5 mL) (sodium hyaluronate group), and normal saline (model group) were injected into the right knee joint cavity, respectively. The morphology of articular surface and nitric oxide contents in knee joint fluid were observed and determined at 8 weeks after surgery.
RESULTS AND CONCLUSION:The morphology of articular cartilage in the PRP group was better than that in the other three groups. Mankin scores of articular cartilage and nitric oxide contents of knee joint fluid in the PRP group were significantly decreased compared with the model and sodium hyaluronate groups that in (P<0.05), while increased compared with the sham-operation group (P<0.05). Our results suggest that repair effects of PRP on the damaged articular cartilage are superior to sodium hyaluronate treatment.

OBJECTIVEThis study aims to assess and compare the prevalence of Porphyromonas endodontalis (P. endodontalis) in root canals associated with primary and secondary endodontic infections by using 16s rDNA PCR and real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR).

METHODSA total of 120 adult patients with one radiographically documented periapical lesion were included. Sixty teeth presented with primary endodontic infections and 60 with secondary endodontic infections requiring retreatment. P. endodontalis was identified by using 16s rDNA PCR techniques. The positive DNA expression of P. endodontalis in two types of infected root canals were quantitatively compared by using SYBR GREEN I RTFQ-PCR.

RESULTSThe prevalence of P. endodontalis in the root canals with primary endodontic infections was significantly higher than that in root canals with secondary endodontic infections (P = 0.001). However, RTFQ-PCR results showed no significant difference in DNA expression quantities between the primary and secondary endodontic infections root canals (P = 0.303).

CONCLUSIONP. endodontalis is more highly associated with root canals having primary endodontic infections, although P. endodontalis colonize in both root canals with primary and secondary chronic apical periodontitis.

BACKGROUND:More recently, the focus has been on searching for a compound Chinese medicine for reinforcing kidney, which cannot only inhibit bone absorption, but also promote osteogenesis to protect against osteoporosis. OBJECTIVE:To explore effects of drug serum of Jianbuhuqian pil s on proliferation and function of osteoblast-like cel s in vitro. METHODS:Twenty-four adult female Sprague-Dawley rats were randomly divided into low-dose, medium-dose, high-dose and normal saline groups, and given intragastric administration of 1.5, 3.0, and 6 g/kg Jianbuhuqian pills and equal volume of normal saline, respectively twice daily for 1 week. At 1 hour after final gavage, rats were decapitated to prepare drug sera used for culturing osteoblast-like cells. At 24, 48 and 72 hours of culture, the cellular morphology was observed, as well as the cell proliferation and alkaline phosphatase activity was detected by MTT assay and alkaline phosphatase staining, respectively. RESULTS AND CONCLUSION:Compared with the normal saline group, the cel density began to increase significantly in three Jianbuhuqian groups at 24 hours after culture, mitotic figures were easy to be observed, cel s were in overlapping growth, much secretions and matrix accumulation appeared, especial y in the high-dose group. The obsorbance values in Jianbuhuqian groups were significantly higher than that in the normal saline group. After 24 hours of culture, the obsorbance values in the medium-dose and high-dose groups were significantly increased compared with the low-dose group, and the values showed significant differences among three Jianbuhuqian groups after 48 and 72-hour culture. In addition, the alkaline phosphatase activity presented overt increase in the Jianbuhuqian groups compared with the normal saline group, and significant differences could be found among Jianbuhuqian groups. To conclude, the drug serum of Jianbuhuqian pil s can promote the activity of osteoblast-like cel s in a time-and concentration-dependent manner.

Objective To study the prevalence of Parvimonas micra(Pm) and the associations between Pm and pulp dominant pathogens in order to reflect the colonization of Pm in the infected root canals with chronic periradicular periodontitis.Methods A total of 120 teeth diagnosed as chronic periradicular periodontitis from 104 patients were included into the study.The teeth were allocated into untreated (primary infectious) and root-canal-treated (secondary infectious) groups with 60 in either group.Samples were collected from the root canals using sterile files and paper points,and subsequent extraction of bacterial DNA was undertaken.The Pm 16S rDNA level was evaluated using 16S rDNA PCR.The prevalence of Pm in chronic periradicular periodontitis was determined accordingly.Then,the associations of Pm and Enterococcus faecalis(Ef),Porphyromonas endodontalis(Pe) as well as Porphyromonas gingivalis (Pg) were analysed.Results Pm was detected in 40％ (24/60) of the samples from the primary infectious group,5％ (3/60) from the secondary infectious group.The prevalences of Pm from the two groups were different significantly (x2=21.06,P＜0.05).Significant correlations (untreated group OR=5.98,root-canaltreated group OR=33.50) between Pm and Pe were identified in both groups,while the correlations between Pm and Pg as well as Ef were not of significance,respectively.Conclusions A significantly higher relevance ratio of Pm was estimated in the primary infectious group than the secondary infectious one.Pm and Pe were correlated significantly in the infected root canals,suggesting a symbiotic relation between these two bacteria.

Objective This study aims to assess and compare the prevalence of Porphyromonas endodontalis (P. endo-dontalis) in root canals associated with primary and secondary endodontic infections by using 16s rDNA PCR and real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR). Methods A total of 120 adult patients with one radio-graphically documented periapical lesion were included. Sixty teeth presented with primary endodontic infections and 60 with secondary endodontic infections requiring retreatment. P. endodontalis was identified by using 16s rDNA PCR techni-ques. The positive DNA expression of P. endodontalis in two types of infected root canals were quantitatively compared by using SYBR GREEN Ⅰ RTFQ-PCR. Results The prevalence of P. endodontalis in the root canals with primary endodontic infections was significantly higher than that in root canals with secondary endodontic infections (P=0.001). However, RTFQ-PCR results showed no significant difference in DNA expression quantities between the primary and secondary endodontic infections root canals (P=0.303). Conclusion P. endodontalis is more highly associated with root canals having primary endodontic infections, although P. endodontalis colonize in both root canals with primary and secondary chronic apical periodontitis.

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment.However,irrigant selection or irrigation procedures are far from clear.The vapor lock effect in the apical region has yet to be solved,impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.Additionally,ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified.Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes.Indeed,clinicians have been aware of these concerns for years.Based on the current evidence of studies,this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions.The evolution of different kinetic irrigation methods,their effects,limitations,the paradigm shift,current indications,and effective operational procedures regarding intracanal medication are also discussed.This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication,thus facilitating a better understanding of infection control,standardizing clinical practice,and ultimately improving the success of endodontic therapy.