PLGA/PCL/nHA生物支架复合兔BMSCs体外培养的实验研究

目的:研究新型复合支架聚乳酸-聚乙醇酸/聚己内酯/纳米羟基磷灰石(PLGA/PCL/nHA)的生物相容性,探讨其作为细胞培养材料和骨组织工程支架的可行性.方法:将兔骨髓基质细胞(bone marrow stromal cells,BMSCs)接种于PLGA/PCL/nHA复合支架上,体外共同培养后,MTT法检测BMSC...     

新型多孔磷酸钙复合骨髓基质干细胞组织工程实验研究

目的观察新型生物材料多孔磷酸钙的生物相容性及复合骨髓基质干细胞（BMSCs）异位成骨情况。方法体外培养第2代Beagle犬BMSCs,转染绿色荧光蛋白（GFP）后与多孔磷酸钙（CPC）复合培养,获得最佳复合浓度,倒置和荧光显微镜、扫描电镜下观察BMSCs黏附和生长情况,复合体植入裸鼠皮下8周观察异位成骨。结果BMSCs转染GFP与多孔CPC复合培养1 d,细胞从材料中爬出,形态正常,7 d可见细胞伸出伪足,分泌基质;复合体可异位成骨。结论多孔CPC生物相容性好,是一种较理想的骨组织工程支架材料。     

体外培养狗骨髓基质细胞在牙根上生长的超微结构

目的：探讨体外培养的骨髓基质细胞及其与牙根复合后的生长特性，为牙周组织工程载体材料的选择提供实验依据。方法：分离纯化的狗骨髓基质细胞与牙根复合体外培养，分别在相差显微镜和扫描电镜下动态观察细胞及其与牙根复合生长的形态变化。结果：骨髓基质细胞在牙根上贴附生长、增殖良好，功能正常。结论：牙根与骨髓基质细胞具有良好的生物相容性，可能成为牙周组织工程的载体材料选择。     

无机诱导因子复合性骨支架材料的生物相容学研究——兼论人体外复合细胞相容性观察

目的用预制型无机诱导因子复合性骨组织工程支架材料对实验动物山羊的下颌骨角部大型箱状缺损行骨重建，评价其及其降解产物对血液和植入区周围组织的生物相容性反应；和人体外复合细胞培养的生物相容性观察。方法15只雌性山羊作为实验组，术后4，8，12w处死动物对相关重要脏器进行大体解剖学和组织病理观察；另取雌性山羊15只作为对照组；培养人骨髓基质细胞行细胞形态、电镜和MTT观察。结果血液学检测，实验组与对照组均在正常值范围内，两组间差别无统计学意义；实验组重要脏器组织病理学未见形态改变和炎性细胞浸润；支架置入区域病检符合组织工程骨的愈合过程；人体外复合细胞培养的检测中未见明显异常。结论生物相容性观察提示：本支架材料无急慢性毒性反应和超敏反应，对人骨髓基质细胞的形态、生长和增殖无明显抑制作用，具有良好的生物相容性。     

无机诱导因子骨组织工程支架材料体外细胞相容性的实验研究

目的：细胞毒性和细胞相容性是生物材料应用于临床首先必须面对的问题.通过对无机诱导因子骨组织工程支架材料的体外实验,来研究其细胞毒性和细胞相容性,为其临床应用作前期准备.方法：将生长状态良好的人骨髓基质细胞与无机诱导因子支架材料浸提液共同培养,通过镜下观察细胞形态、MTT比色法、流式细胞仪检测法评价生物材料浸提液对人骨髓基质细胞生长和增殖的影响;并将人骨髓基质细胞接种于无机诱导因子支架材料上,扫描电镜观察材料细胞复合物生长状况.结果：人骨髓基质细胞能够在无机诱导因子支架材料上生长,支架材料对体外培养的人骨髓基质细胞的形态不构成损害,对细胞的生长和增殖无明显抑制作用.结论：无机诱导因子支架材料具有良好的细胞生物学相容性,是一良好的组织工程骨构建支架材料.     

气电纺聚羟基丁酸酯支架用于大鼠骨髓基质细胞体外培养的研究

目的研究气电纺聚羟基丁酸酯[poly（3-hydroxybutyrate）,PHB]纳米纤维支架的体外生物相容性。方法实验组用PHB纳米纤维支架接种大鼠骨髓基质细胞进行体外培养,对照组用培养板培养孔接种大鼠骨髓基质细胞进行体外培养,通过扫描电镜、四甲基偶氮唑盐比色法以及碱性磷酸酶（alkaline phosphatase,ALP）检测来评价PHB纳米纤维支架对大鼠骨髓基质细胞粘附、增殖活性以及ALP活性的影响。结果气电纺PHB纳米纤维支架材料对大鼠骨髓基质细胞具有良好的亲和性;与细胞培养板相比,气电纺PHB纳米纤维支架材料上的大鼠骨髓基质细胞具有较高的增殖活性及ALP活性。结论气电纺PHB纳米纤维支架有望用作骨组织工程支架材料。     

新型多孔HA/PDLLA支架体外细胞相容性的实验研究

目的:研究新型多孔羟基磷灰石/聚乳酸(HA/PDLLA)支架材料的体外细胞相容性。方法:贴壁法培养兔骨髓基质细胞(bone marrow stromal cells,BMSCs),经体外矿化诱导培养、扩增后,与实验组 A(含2%HA 的 HA/PDLLA)、实验组 B(含4%HA 的 HA/PDLLA)及对照组(PDLLA)分别进行体外复合培养;并通过定性及定量检测细胞在材料表面的粘附能力、增殖活力,验证细胞材料复合体的成骨活性,比较分析各组支架材料之间的差异。结果:兔 BMSCs在三组支架材料的表面均能生长,经体外诱导后在支架材料的表面形成钙结节,实验组 A 与 B 细胞的粘附及增殖能力均强于对照组(P<0.05)。结论:兔 BMSCs 与新型多孔 HA/PDLLA 支架材料有良好的细胞相容性。     

电纺聚己内酯/Ⅰ型胶原蛋白/纳米锆酸钙复合支架的制备及其生物相容性的研究

目的:制备聚己内酯(PCL)/Ⅰ型胶原(COLI)/纳米锆酸钙(nCZ)复合支架用于骨组织再生,评价其性能及对人牙周膜细胞(PDLCs)生物相容性及成骨分化的影响.方法:用静电纺丝法制备PCL/COLI、PCL/COLI/纳米羟基磷灰石(nHA)和PCL/COLI/nCZ复合支架,通过扫描电子显微镜表征支架形貌,能量色...     

口腔颌面部整复

带颈横血管上斜方肌肌皮瓣即刻修复舌癌术后缺损21例报道;骨髓基质细胞复合三维支架修复犬下颌骨节段性缺损;犬骨髓基质细胞和β-磷酸三钙复合物在裸鼠体内的成骨性能;犬骨髓基质细胞和β-磷酸三钙复合物的体外构建;无机诱导因子支架材料行颌骨重建的放射学评价     

犬骨髓基质细胞和β-磷酸三钙复合物的体外构建

目的：研究犬骨髓基质细胞（bone marrow stromal cells，BMSCs）在体外骨诱导环境下和支架材料β-磷酸三钙（β-TCP）复合的可能性和生物材料的性能。方法：抽取犬骨髓3ml，在DMEM成骨条件培养液条件下贴壁法进行体外培养，将培养的第3代细胞接种于预制的3mm^3大小的β-TCP上进行体外骨诱导条件下培养，于培养第4h、第2d、第5d取细胞材料复合体进行扫捕电镜检查。结果：扫描电镜观察：材料呈多孔三维立体网状结构，平均孔径约450μm，孔内连接径约100μm。细胞接种在材料上4h后可见附着：2d后．细胞呈多角形向外伸展；5d后，细胞和材料表面紧密贴附，细胞充分伸展，分泌基质。结论：β-TCP具有良好的多孔三维立体结构和生物相容性．利于BMSCs的附着和生长，可作为骨组织工程支架材料复合种子细胞进行体内成骨研究。     

Modulation of clinical expression of plaque-induced gingivitis. II. Identification of "high-responder" and "low-responder" subjects

AIM: The aims of this study were to validate a randomized, split-mouth, localized experimental gingivitis model and to identify subjects with different gingivitis susceptibility. MATERIAL AND METHODS: In each of 96 healthy subjects, one maxillary quadrant was randomly assigned as "test" (experimental gingivitis) and the contralateral quadrant as "control". Plaque index (PlI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded in both quadrants at days 0, 7, 14, and 21. Cumulative plaque exposure (CPE), i.e. PlI over time, was calculated. Day-21 GCF was standardized according to CPE, and residuals of GCF on CPE were calculated. Two subpopulations were then defined, based on upper and lower quartiles of GCF-residual distribution and were, respectively, identified as "high-responder" (HR; n=24) and "low-responder" (LR; n=24). RESULTS: At test quadrants, all parameters significantly increased throughout the trial, while in control quadrants, PlI, GI, and AngBS remained low. Significant differences were noted between test and control quadrants on days 7, 14, and 21 for all parameters. Significant increases in GI, AngBS, and GCF were observed in test quadrants over the course of the study in both HR and LR groups. Significant differences were noted between HR and LR groups for all gingivitis parameters on day 21 in test quadrants, without any significant differences in PlI or CPE between the groups. CONCLUSIONS: We identified two subpopulations characterized by significant differences in clinical parameters of plaque-induced gingival inflammation, despite similar amounts of plaque deposits and plaque accumulation rates.     

Recovery of A. actinomycetemcomitans from teeth, tongue, and saliva

The recovery of actinobacillus actinomycetemcomitans simultaneously from subgingival sites around teeth and dorsum of the tongue and/or saliva was examined in 293 subjects at 444 visits; 295 paired samples were available from subgingival sites and tongue, 171 paired samples from subgingival sites and stimulated saliva, and 137 paired samples from subgingival sites and unstimulated saliva. Sixty-one subjects were periodontally healthy (mean age 20.3 years); 55 exhibited localized juvenile periodontitis (mean age 21.8 years); 176 adult periodontitis (mean age 46.7 years); and 1 prepubertal periodontitis (age 10 years). When A. actinomycetemcomitans was recovered from subgingival sites, it was also found in 56.3%, 69.9%, and 35.9% of the paired samples from tongue, and stimulated and unstimulated saliva, respectively. No difference in the detection rate of A. actinomycetemcomitans from tongue or stimulated saliva was seen between the subjects with healthy or diseased periodontium. When A. actinomycetemcomitans was not recovered from subgingival sites, it was cultured in 6.8%, 2.0%, and 1.4% of the paired samples from tongue, and stimulated and unstimulated saliva, respectively. In search for noninvasive, inexpensive, and easily run sampling methods for the recovery of oral A. actinomycetemcomitans samples from stimulated saliva and tongue may prove useful in clinical periodontology.     

Bis-GMA/TEGDMA树脂水解产物分析

目的检测Bis-GMA/TEGDMA树脂片经去离子水浸泡后的水解产物。方法 Bis-GMA/TEGDMA单体加入CQ/DMAEMA后光照聚合制备树脂片,将树脂片经37℃恒温去离子水浸泡24 h,其中在1h、3 h、6 h和24 h四个时间点各取1 mL浸泡液,用乙酸乙酯萃取、旋蒸,通过高效液相色谱质谱法(HPLC/MS)检测分析,确定树脂水解产物。结果树脂片的水解产物为双酚A-二甘油醚(Bis-GMA-2MA)、双酚A-二氧代丙基醚(Bis-GMA-2MA-2H2O)、单甲基丙烯酸二缩三乙二醇酯(TEGDMA-MA)和二缩三乙二醇(TEGDMA-2MA)。结论 Bis-GMA/TEGDMA树脂片经去离子水浸泡后树脂可发生水解,水解产物及残余Bis-GMA/TEGDMA树脂单体可析出并释放到去离子水中。     

Use of antimicrobial agents during supportive periodontal therapy

Individual susceptibility to periodontal breakdown involves an interplay of genes, periodontal pathogens and other modulating factors. Anti-infective treatment, which includes oral hygiene measures, mechanical debridement, pharmacologic intervention and surgery, has been shown to be effective in arresting the progression of periodontal disease. Nevertheless, due to the chronic nature of the disease, susceptible individuals who are not maintained in a supervised recall program subsequent to the active treatment phase, show signs of recurrent destruction. Supportive periodontal therapy (SPT) is an integral part of periodontal treatment for patients with history of periodontitis, and is needed to prevent recurrence of disease in susceptible individuals. To prevent re-infection with periodontal pathogens, SPT includes elimination of dental plaque and bacteria from the oral cavity, thereby preventing the recurrence of pathogens into the gingival area. For individuals at risk of developing periodontitis, SPT should combine self-performed and professional anti-infective therapy, using mechanical and pharmacological means. The existing evidence suggests that the adjunctive use of antimicrobial pharmacologic therapy during SPT may enhance the results of mechanical debridement. The use of antimicrobials varies between patients, and is dependent on risk assessment and longitudinal monitoring of the clinical status of the periodontium.     

Comparative immunohistochemical identification and relative distribution of immunocompetent cells in sections of frozen or formalin-fixed tissue from human periapical inflammatory lesions

Abstract The presence of immunocompetent cells (B, Th/i and Ts/c cells and macrophages) and the ratios of these cell populations in periapical lesions (radicular granulomas, radicular cysts and apical scars) were demonstrated immunohistochemically using paraffin and cryo-sections. Thirty-four human periapical lesions were examined for the presence of immunocompetent cells by monoclonal antibodies and the biotin-avidine-horse-radish peroxidase method. The T/B cell ratio of radicular cysts was significantly higher than that of both radicular granulomas and apical scars, and the average number of Th/i cells was greater than that of Ts/c cells in the radicular granulomas. However, no significant difference was found between radicular cyst and apical scar. The number of macrophages in radicular granulomas was significantly higher than that of the other lesions. These findings suggested that periapical lesions develop as a result of both humoral and cell-mediated immunological response and indicated that the ratios of immunocompetent cells are different in the different types of periapical lesion.     

Clinical and antimicrobial effects of a single episode of subgingival irrigation with tetracycline HCI or chlorhexidine in deep periodontal pockets

Abstract. 15 adults, each providing 4 non-adjacent untreated periodontal pockets with a probing depth (PD) exceeding 6 mm. volunteered for a randomized, split-mouth, double-blind, clinical study evaluating subgingival irrigation with chlorhexidine (CHX) or tetracycline HCl (TTC). The study protocol included oral hygiene instructions followed by scaling and root planing. Experimental and immediately adjacent teeth did not receive instrumentation. The 4 deep periodontal pockets in each patient were assigned to be irrigated with 150 ml CHX (0.12%). TTC (10 or 50 mg/ml; TTC10, TTC50), or sterile saline (control) in a single episode. Post-irrigation mechanical plaque control was supported by 2× daily CHX rinses throughout the 12-week observation interval. Recordings of oral hygiene (PlI), gingival health (GI). bleeding on probing (BoP). probing depth (PD), clinical attachment level (CAL), and microbial morphotypes from subgingival paper point samples were performed pre-irrigation. and at 1, 2, 4, 6, 8, 10, and 12 weeks post-irrigation. Mean post-irrigation PlI was low, fluctuating between 0.0 and 0.4, without significant differences between experimental groups. Mean pre-irrigation GI approximated 1.4 and reached 0.8 at the exit of study without significant differences between experimental groups. All experimental sites exhibited BoP pre-irrigation. BoP was significantly reduced in TTC50 compared to TTC10, CHX and control sites from week 8 post-irrigation. PDs were reduced for the experimental groups with TTC50 exhibiting the strongest reduction. CALs remained unaltered from pre-irrigation for TTC10. CHX and control sites over the 12-week observation interval, whereas TTC50 sites consistently improved to significantly differ from all other groups at week 10 and 12 post-irrigation. The distribution of bacterial morphotypes was significantly altered towards one of periodontal health for all experimental groups with a profound effect for TTC50 sites. Our results suggest that subgingival irrigation with TTC solutions at high concentrations may have a rôle in the management of adult periodontitis.     

Factitious Injury of the Oral Mucosa: A Case Series

Gingival and oral mucosal tissues can be the site of a number of mucocutaneous and ulcerative conditions. Generally, these are not difficult to identify on the basis of clinical characteristics, and diagnosis can be aided by the use of routine histopathological and immunopathological techniques as well as other laboratory investigations. Self-induced or factitious injury (FI) of the oral mucosal tissues may present a confusing clinical picture, and be diagnosed erroneously as a mucocutaneous disorder in spite of the absence of appropriate pathological and immunopathological findings, or a failure to respond to routine treatment. A case series is presented here outlining 4 cases of FI which presented initially as mucocutaneous disease. These cases were investigated to rule out systemic or local causes, in order to establish a diagnosis of FT Treatment of these conditions was facilitated with placebo or sham procedures which were designed primarily to cover the lesions. In most cases, the self injurious behavior could be linked to secondary gain. J Periodontol 1995;66:241–245.     

Centric relation definitions taught in 7 dental schools: Results of faculty and student surveys

PURPOSE: The purpose of this investigation was to assess the level of consensus regarding the definition of centric relation and its clinical use in 7 US dental schools. MATERIALS AND METHODS: The preclinical and clinical faculty in the departments of prosthodontics, operative, and general dentistry (n = 137) at 7 dental schools and a convenience sample of fourth year students (n = 150) at the same schools were invited to complete 2-page surveys regarding the definitions and use of centric relation at their institutions. The faculty and student survey included 6 commonly used centric relation definitions from the 1994 Glossary of Prosthodontic Terms, and provided space for writing in definitions not listed on the form. The participants were asked to identify which definition was used at their school. RESULTS: Return rate was 85% for faculty and 75% for students. Both faculty and students identified a low level of consensus regarding the definition and clinical use of centric relation at their dental school. Numerous definitions are in use at each institution. Extramural practice participation and the number of years since dental school graduation were variables associated with the faculty's choice of definition. The faculty who did not participate in an extramural practice chose older definitions. Dental educators graduating before 1975 selected either the oldest or the most recent centric relation definition, whereas the more recent graduates frequently selected the newer definitions. There were no statistical differences between prosthodontic specialists and nonspecialists in choice of definitions. Three courses identified by the students as having the most influence on their understanding of centric relation were preclinical removable prosthodontics, preclinical occlusion, and clinical removable prosthodontics. CONCLUSION: The results of this survey suggest that the controversy will continue, because to date there is no consensus regarding the definition of centric relation within the 7 dental schools surveyed.     

Removal of Interproximal Subgingival Plaque by Hand and Automatic Toothbrushes

Subgingival plaque removal at interproximal sites by automatic and hand toothbrashes was compared with control sites at which cleansing was not performed. There were 58 patients, 35 to 63 years of age, each with one hopeless tooth requiring extraction. Each patient was randomly assigned to. one of four test groups: hand brash; automatic toothbrush 1; automatic toothbrush 2; and no brushing. The brushing instructions as stated by the manufacturers were demonstrated and the patient brushed the sextant containing the test tooth for 20 seconds. The level of the gingival margin was marked at each interproximal test site. The teeth were extracted and processed for SEM, and subgingival plaque was viewed at X100 and X2000 magnifications. A montage of photomicrographs of the gingival groove to the occlusal margin of the bacterial plaque at XI00 magnification was made and the distance from the groove to the margin was measured. An ANOVA was performed using P = 0.05 level for significance. Due to processing difficulties, only 33 specimens were available for analysis. The average distances from the groove to the subgingival plaque front for the four test groups were 0.514, 0.132, 0.163, and 0.111 mm respectively. The maximum distance (1.5 mm) of plaque removal was greatest for the hand toothbrush. Due to the large standard deviation (0.636 compared to 0.146, 0.250, and 0.124 respectively), the hand brushing group was excluded from ANOVA. There were no statistically significant differences among the automatic toothbrashes and the no brushing control (P = 0.8393). It was concluded that a single session of oral hygiene instruction with an automatic toothbrush did not result in subgingival inteiproximal plaque cleansing. J Periodontol 1995; 66:191–196.     

Modulation of clinical expression of plaque-induced gingivitis. III. Response of "high responders" and "low responders" to therapy

AIM: The aim of the present study was to characterize the subject-based clinical behavior of the gingiva in response to a tooth-cleaning regimen in two subpopulations, "high-responder" (HR) and "low-responder" (LR) groups, presenting a different inflammatory response to plaque accumulation. MATERIAL AND METHODS: The study population comprised of 96 systemically and periodontally healthy subjects, 46 males and 50 females, non-smokers, enrolled in an experimental gingivitis trial. At completion of the experimental gingivitis period (day 21), all subjects were prescribed the same 21-day treatment regimen of amine/stannous fluoride (AmF/SnF(2))-containing toothpaste and mouthrinse. Plaque index (PlI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded on three selected teeth. Treatment efficacy was evaluated in the overall population as well as in HR and LR groups, separately. RESULTS: A statistically significant decrease of PlI was observed after treatment (p<0.001), with PlI reversing to baseline levels. Changes in PlI revealed the same trend in both HR and LR groups, without differences between groups. Treatment also resulted in a significant decrease of all gingivitis parameters (p<0.001 for all comparisons). After treatment, GI, AngBS, and GCF were comparable with baseline condition. However, when the two groups were compared, day 42-GCF was significantly higher in the HR group than the LR group. CONCLUSIONS: A treatment regimen based on mechanical plaque control supplemented with AmF/SnF(2)-containing toothpaste and mouthrinse is effective in reducing plaque accumulation and re-establishing healthy gingival conditions after experimentally induced gingivitis, even in subjects with different inflammatory response to plaque accumulation.