生物安全柜中不同包装物影响灭菌口腔器械有效期的研究

目的探讨不同包装对灭菌口腔小器械在生物安全柜中的有效期的影响。方法在生物安全柜中,对高压灭菌后玻璃器皿包装和纸塑包装的口腔小器械在不同时间点进行细菌采样培养实验,在第1天打开玻璃器皿包装的灭菌小器械后的4、8、24 h进行采样,以后每间隔24小时采集1次,连续10 d采样观察其细菌生长情况,同时在每一个时间点均采集一次纸塑包装的灭菌器械作为实验对照。结果在生物安全柜相对无污染的情况下,对照组均无细菌生长,实验组在144 h的培养结果开始有菌落生长,168 h后的培养结果有统计学意义(P<0.05)。结论在生物安全柜中相对无污染的条件下,玻璃器皿包装的口腔诊疗中的小器械的有效期远远超过《医疗机构口腔诊疗器械消毒技术操作规范》所规定的包装灭菌物品一经打开不得超过4 h的标准。     

HtrA 对乳牙高致龋性变异链球菌 GTFs 表达及活性的影响

目的：研究乳牙高致龋性变异链球菌（S．mutans）高温需要 A 蛋白（HtrA）基因缺陷株和 HtrA 高毒力株在体外非应激环境中的葡萄糖基转移酶（GTFs）表达能力及其生物学活性的差异。方法：选用前期已获得的乳牙高致龋性 S．mutans HtrA 基因缺陷株和高毒力株（HtrA 高毒力株和 HtrA 基因缺陷株）,在 BHI 培养基培养至指数期第10 h 后。以实时逆转录聚合酶链反应（real-time RT-PCR）方法检测2菌株 gtfB,gtfC,gtfD 的表达情况。提取蛋白,以蒽酮硫酸法检测其生物学活性,以蛋白免疫印迹（Western Blot）检测其表达量。结果：GTFs 蛋白和基因在乳牙 S．mutans HtrA 基因缺陷株中的表达高于 HtrA 高毒力株,但其生物学活性低于高毒力株。结论：HtrA 基因在乳牙 S．mutans GTFs 的分泌过程中起重要的调控作用。     

米诺环素联合康复新液对慢性牙周炎疗效及血清PD-1、PD-L1表达的影响

［摘要］ 目的 探讨米诺环素联合康复新液对慢性牙周炎疗效及血清程序性细胞死亡1（programmed death-1,PD-1）、程序性细胞死亡配体1（programmed death-ligand 1,PD-L1）表达的影响。 方法 192例牙周炎患者,随机数字表法分为2组各96例,观察组采用米诺环素联合康复新液治疗,对照组采用米诺环素治疗,观察2组临床疗效和总有效率,比较组2组菌斑、牙周探诊深度、牙龈出血指数;比较2组治疗前后血清炎症因子变化;比较2组治疗前后血清PD-1和PD-L1水平变化和不良反应。 结果 观察组临床疗效和总有效率均高于对照组（P＜0.05）;观察组菌斑指数、牙周探诊深度、牙龈出血指数均低于对照组（P＜0.05）;治疗后2组血清因子干扰素γ（interferon-γ,IFN-γ）、肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）、白细胞介素8（interleukin-8,IL-8）和超敏C反应蛋白（hypersensitive C-reactive protein,hs-CRP）均较治疗前明显降低（P＜0.05）,IL-10均较治疗前明显升高（P＜0.05）,观察组降低和升高幅度较大,治疗后观察组血清因子IFN-γ、TNF-α、IL-8和hs-CRP低于对照组,（P＜0.05）,2组不良反应发生率差异无统计学意义（P＞0.05）。 结论 米诺环素联合康复新液可有效降低慢性牙周炎患者血清CD4+、CD8+T淋巴细胞上PD-1和PD-L1表达,缓解炎症反应,改善临床症状,提高治疗效果。     

In vitro proliferation of periodontal ligament-like tissue on extracted teeth

ObjectiveTransplantation of autologous teeth is a routine component of orthodontic treatment. The aim of this study was to develop a method for the regeneration of damaged periodontal ligament (PDL) on extracted teeth using a three-dimensional culture system.DesignWe used the maxillary first premolars or third molars extracted from patients for orthodontic treatment. The extracted teeth were stained with toluidine blue to measure the residual PDL area. After confirming damage of the periodontal tissue on the root surface of the extracted teeth, we tried to regenerate the periodontal tissue. Other extracted teeth were inserted into a cell strainer filled with cellulose-based carrier materials to regenerate the periodontal tissue. The strainer was then placed in a 90-mm culture dish filled with culture medium and incubated at 37 °C and 5% CO2 for about 1 month. The cultured teeth were observed under a stereomicroscope and examined by scanning electron microscopy (SEM), and were stained to detect alkaline phosphatase (ALP) activity.ResultToluidine blue staining revealed that the residual periodontal membrane covered an average of 50.4% of the root surface area of each tooth. After culturing extracted teeth with our culture system, globular structures were found on the entire tooth root surface by stereomicroscopy, and PDL-like filamentous tissue was also detected by SEM. The entire tooth root surfaces of the cultured teeth were positive for ALP activity.ConclusionsWe have developed a useful culture method to stimulate the proliferation of cells in PDL-like tissue on the roots of extracted teeth.     

Tomographic and histomorphometric evaluation of socket healing after tooth extraction using leukocyte- and platelet-rich fibrin: A randomized,single-blind,controlled clinical trial

The use of platelet concentrate in alveolar ridge preservation has been broadly studied. However, no randomized clinical trials with histomorphometric analysis and low risk of bias are available in the literature. We conducted a prospective, single-blind, parallel, randomized, controlled clinical trial to evaluate the efficacy of leukocyte- and platelet-rich fibrin (L-PRF) in socket preservation after tooth extraction. Additionally, the effect of L-PRF on bone formation was analyzed histologically using bone biopsy specimens obtained during implant placement.A total of 48 subjects who underwent a non-molar tooth extraction were randomly assigned to the L-PRF group (n = 24) or the control group (n = 24). Cone-beam computed tomographies were performed immediately after tooth extraction and at 3 months after tooth extraction, prior to implant surgery. A significant difference in bone resorption was registered 1 mm below the crest: 0.93 ± 0.9 mm for the L-PRF group and 2.27 ± 1.2 mm for the control group (p = 0.0001). Histomorphometric analysis showed a higher percentage of new bone formation in the L-PRF group compared with the control group. The values were 55.96 ± 11.97% and 39.69 ± 11.13%, respectively (p = 0.00001). These findings indicate that the administration of L-PRF should always be considered when socket preservation is planned (Clinicaltrials.gov NCT03408418).     

股前外侧肌皮瓣及CT血管造影在修复中晚期口底癌术后缺损中的应用

目的 探讨游离股前外侧肌皮瓣在中晚期口底癌术后缺损修复重建中的治疗效果及CT血管造影（CTA）定位股前外侧肌皮瓣穿支血管的应用价值。方法 对16例中晚期口底癌患者在施行口底癌根治性切除术同时运用游离股前外侧肌皮瓣行软组织缺损的修复重建,术前应用CTA定位旋股外侧动脉及穿支血管。结果 16例患者术前CTA定位的穿支血管与术中所见完全吻合,股前外侧肌皮瓣移植手术均获成功。术后随访6~36个月,患者的口底、舌外形恢复良好,张口度理想,吞咽及语言功能满意,供区无明显后遗症,肿瘤局部无复发,其中1例患者（T4N2M0期）在术后10个月因发生远处转移而死亡。结论 CTA能精确定位旋股外侧动脉及穿支血管,游离股前外侧肌皮瓣是修复重建中晚期口底癌术后组织缺损的理想选择。     

不同型号扩锉针旋入离体牙牙根后的拉出力分析

目的 比较不同型号扩锉针旋入离体牙牙根后的拉出力,明确扩锉针微创拔除牙根的力学基础.方法 900颗离体磨牙牙根,随机分组后截根,按牙根长度分为3组:3mm、5mm和7mm组,每组300颗;分别将不同型号的H锉和K锉旋入牙根,使用万能力学试验机进行拉出实验,测试扩锉针的拉出力即扩锉针与牙根之间的最大摩擦力阻力.结果 相同号数的扩锉针,旋入同一长度牙根时,使用H锉拉出力大于K锉,其差异具有统计学意义(P＜0.05).不同号数的同种扩锉针,旋入同一长度牙根时,K锉和H锉的拉出力均为:25#＞30#＞20#,其差异具有统计学意义(P＜0.05).结论 临床上选择扩锉针拔除磨牙牙根时宜优先选择25#H锉,但根管较粗大时可以选用较大型号的H锉.     

A comparative study of the regenerative effect of sinus bone grafting with platelet-rich fibrin-mixed Bio-Oss® and commercial fibrin-mixed Bio-Oss®: An experimental study

Anorganic bovine bone (Bio-Oss^®) particles are one of the most popular grafting materials. The particles are often mixed with platelet-rich fibrin (PRF) or a commercial fibrin (Tisseel^®) to form a mouldable graft material. The objective of this study was to compare the potentials of PRF-mixed Bio-Oss^® and Tisseel^®-mixed Bio-Oss^® to enhance bone regeneration in a canine sinus model. Six mongrel dogs were used in this study. After elevating the sinus membrane in both maxillary sinus cavities, an implant was placed into the sinus cavity. In one of the sinus cavities, the PRF/Bio-Oss^® composite was grafted, and the Tisseel^®/Bio-Oss^® composite was grafted in the other sinus cavity. After a 6 month healing period, bone formation in the graft sites and bone-implant contact were evaluated. The mean osseointegration rate was 43.5 ± 12.4% and new bone formation rate 41.8 ± 5.9% in the PRF/Bio-Oss^® composite sites. In the Tisseel^®/Bio-Oss^® composite sites they were 30.7 ± 7.9% and 31.3 ± 6.4%. There were statistically significant differences between the groups. The findings from this study suggest that when platelet-rich fibrin is used as an adjunct to Bio-Oss^® particles for bone augmentation in the maxillary sinus, bone formation in the graft sites is significantly greater than when Tisseel^® is used.