Modulation of osteogenic potential by recombinant human bone morphogenic protein-2 in human periodontal ligament cells: effect of serum, culture medium, and osteoinductive medium

BACKGROUND AND OBJECTIVE: Bone morphogenic proteins are known, in animal models, to promote many developmental processes, including osteogenesis. Clinical trials are currently underway to evaluate the potential of bone morphogenic proteins to promote bone and periodontal regeneration in humans. The aim of this study was to establish an optimal cell culture condition for using to study the biological effects of recombinant human bone morphogenic protein-2 on periodontal ligament cells. MATERIAL AND METHODS: The roles of serum concentration, types of culture medium (alpha-modified essential medium or Dulbecco's modified Eagle's medium), the presence of osteoinductive medium (including dexamethasone, ascorbic acid and beta-glycerophosphate), and timing of addition of the osteoinductive medium and recombinant human bone morphogenic protein-2, on the expression of alkaline phosphatase were investigated in cultured periodontal ligament cells. Cytochemical stainings and biological assay of alkaline phosphatase were also demonstrated. RESULTS: Our results suggested that an increased concentration of serum might mask the effect of recombinant human bone morphogenic protein-2 on the expression of alkaline phosphatase in periodontal ligament cells. alpha-Modified essential medium was found to induce a stronger cytochemical staining of the alkaline phosphatase than Dulbecco's modified Eagle's medium under similar culture conditions. Pre-incubation of cells with osteoinductive medium before the addition of various concentrations of recombinant human bone morphogenic protein-2 enhanced greater alkaline phosphatase expression than the simultaneous presence of both osteoinductive medium and recombinant human bone morphogenic protein-2. CONCLUSION: The findings of this study suggest that the effect of recombinant human bone morphogenic protein-2 on periodontal ligament cells could be efficiently investigated after the proper selection of culture variables and temporal sequence of adding bioactive factors. The optimal culture condition identified in this study might be useful in further studies to elucidate the regulatory mechanism of periodontal ligament cells in periodontal regeneration after stimulation with recombinant human bone morphogenic protein-2.     

1354 freshmen's dental investigation]

1354 freshmen have been investigated to discover the relationship between dental diseases and environments,living habits and personal sanitary conditions,because urban young men like sweet foods and snacks,the incidence of caries is greater in the cities than in the country,more people with tetracycline discolored tooth live in urban areas than in the rustic ones,which is due to dense living conditions, vulnerable to respiratory organs disease,medical conditions and convenience of taking tetracycline when ill;on the other hand,gingivitis is more common within the country students than within the city students,for those students from the country are used to brush their tooth after adolescence and usually have more dental calculus which is harmful to the gingiva.More than half of the investigated freshmen are ignorant of correct method of brushing and oral health and that is important factors of high rate of dental disease,according to the above reasons,the effective measures should educated to prevent dental disease.     

The design of a two-part acid-etched resin-bonded fixed partial denture.

A new framework design is presented for resin-bonded, acid-etched, fixed partial dentures. This innovative design divided the restoration into two parts, each with a separate path of insertion. The preparation of abutment teeth required minimal reduction and the pontic could not be displaced during function. Thirty-five patients with missing posterior teeth have been treated with this imaginative approach and after approximately 2 years, there have been no debonding failures.     

免疫化疗与TIUL得率及其杀瘤活性测定

Tumor-infiltrating lymphocyte (TIL) in the primary site of oral SCC treated with S-PVP of PVP therapy was collected respectively and its yield,that is calculating the amount of TIL per tumor tissue.The cytotoxicity of TIL against the target,Tca8113 was detected.The results showed that the yield of TIL in S-PVP group was three times over that in PVP group.At the ratio of 5 to 1 (effector to target) the cytotoxicity was 38% in S-PVP group and 32% in PVP group.There was no significant difference in its cytotoxicity between two groups.The results revealed that immunochemotherapy of S-PVP regimen for treating oral SCC had neither direct damage to tumor cell from the agents nor antitumor immune reactivity with BRM stimulating an increasing in numbers of TIL.     

MRI在口腔颌面部肿块诊断中的应用

作者对38例发生在口腔颌面部肿块患者采用MRI检诊。结合缅针穿吸缅胞学检查，并与CT扫描对比研究。结果提示：对口腔颌面部肿块。管状瘤或临床怀疑肿瘤有颅底、眶尖、翼腭窝、咽侧、颈部大血管神经累及者。MRI扫描成像清晰。软组织分辨率高。能早期发现骨质侵蚀。作者还对MRI在监测颌面部癌瘤切除术后局部是否复发进行初步观察。     

Effect of compounds of Galla chinensis on remineralisation of initial enamel carious lesions in vitro

OBJECTIVE: To evaluate the effect of compounds of Galla chinensis on the remineralisation of initial enamel carious lesions in vitro. METHODS: Sixty bovine enamel blocks with early lesions were prepared and randomly divided into six treatment groups. The lesions were subjected to a pH-cycling regime for 12 days. Each daily cycle included 4x1min applications with one of six treatments; 1000ppm F aq. (as NaF, positive control); deionized water (negative control); or 4000ppm aqueous solutions of four G. chinensis extracts (GCEs); GCE, GCE-B, GCE-B1, or GCE-B2. Surface enamel microhardness was measured on the enamel blocks before and after demineralisation, and after pH-cycling, and percentage surface microhardness recovery (%SMHR) was calculated. The enamel specimens were then sectioned (thickness ca. 80microm) and examined by polarized light microscopy. RESULTS: All samples rehardened significantly compared to baseline. Fluoride had a significantly greater effect than all other treatments. In the GCEs groups, %SMHR was significantly greater than DDW for the GCE, GCE-B and GCE-B1 groups. There was no significant difference between the GCE-B2 group and DDW. Polarized light microscopy showed that the thickness of the surface layer increased obviously in all specimens including NaF group, GCE group, GCE-B group and GCE-B1 group. Negative birefringent band appeared in the lesions body and the depth of the lesions was obviously reduced. CONCLUSION: The present study has demonstrated the potential of three GCEs (GCE, GCE-B and GCE-B1) to effect net rehardening of artificial carious lesions under dynamic pH-cyclic conditions.     

Evaluation of formocresol versus ferric sulphate primary molar pulpotomy: a systematic review and meta-analysis

AIM: To present a systematic review of the effects of formocresol and ferric sulphate when used as medicaments in pulpotomized primary molar teeth. METHODOLOGY: The study list was obtained by using MEDLINE, the Cochrane Library, EMBASE and SCI search. Only those papers which met the inclusion criteria were accepted. The quality of studies used for meta-analysis was assessed by a series of validity criteria according to Jadad's scale. A systematic review and meta-analysis were performed. RESULTS: Eleven clinical studies comprising four randomized-clinical trials (RCTs), four controlled clinical trials (CCTs) and three retrospective studies were included. The results of the meta-analysis of six prospective clinical trials suggested that the two popular pulpotomy medicaments were not significantly different in terms of clinical outcomes, radiographic findings, prevalence of apical and furcal destruction, internal root resorption or pulp canal obliteration. The relative risk (RR) value and 95% CI for those parameters were 0.72 (0.43-1.23), 0.87 (0.59-1.30), 0.67 (0.27-1.66), 1.77 (0.56-5.58) and 1.41 (0.63-3.15), respectively. The overall clinical and radiographic success rates based on the data of treatments with ferric sulphate from the 11 studies included ranged from 78% to 100% (mean 91.6 +/- 8.15%) and from 42% to 97% (mean 73.5 +/- 18.40%), respectively. CONCLUSIONS: In primary molar teeth with exposure of vital pulps by caries or trauma, pulpotomies performed with either formocresol or ferric sulphate have similar clinical and radiographic success. Ferric sulphate may be recommended as a suitable replacement for formocresol.