Observations on the Life Cycle of the Gingival Epithelial Cells of Mice as Revealed by Autoradiography

Abstract

Objective. This study tested the hypothesis that the benefit of fluoride-releasing restorative materials continues even after their reserve of fluoride has been depleted. Materials and methods. Pits in perspex blocks simulating cavities were filled with either a fluoride-releasing or a non-fluoride-releasing restorative material and a dentin single-section was placed 1 mm from the edge of the filled pit. These combinations were exposed to an acid gel system. Each demineralized dentin section was separated from the adjacent material and immersed in fresh demineralizing solutions. Transversal microradiographs were taken following the two experimental periods. This study defined ΔΔZ as the increase of integrated mineral loss (ΔZ) during the second acid attack. Results. The first acid attack substantially demineralized the near-surface region (depth < 40 μm) in all samples. The second acid attack, however, did not cause further demineralization in this near-surface region. Instead, it demineralized dentin deeper than 40–60 μm. The ΔΔZ of the material that did not release fluoride was significantly greater than that of fluoride-releasing materials. Negative correlations were found between ΔΔZ and the mineral volume% of the near-surface region and lesion body of the initial lesions. These results indicate that the dentin mineral in the near-surface region is chemically altered to become acid-resistant fluorapatite. In addition, lesion progression during the second period of demineralization, which was fluoride-free, may have been affected for the materials that have high mineral content of the surface layer and lesion body. Conclusions. It is concluded that dentin surrounding fluoride-releasing materials is protected against demineralization even after the fluoride release has diminished.     

Long‐Term Follow‐Up of Turned Single Implants Placed in Periodontally Healthy Patients After 16 to 22 Years: Microbiologic Outcome

Background: Survival rates in implant dentistry today are high, although late failures do occur for many reasons, including peri‐implant infections. The primary objective of this study is to investigate microbiota around single turned implants after 16 to 22 years. Secondary objectives are to compare teeth and implants and to correlate microbiologic, radiographic, and clinical parameters. Methods: A total of 46 patients with single implants were invited for a clinical examination. Clinical data were collected from implants and contralateral natural teeth. Radiographic bone level was measured around implants. Microbiologic samples were taken from implants, contralateral teeth, and the deepest pocket per quadrant. Samples were analyzed with DNA‐DNA hybridization including 40 species. Statistical analysis was performed using Wilcoxon signed‐rank tests, McNemar tests, and Spearman correlation coefficients with a 0.05 significance level. Results: Mean follow‐up was 18.5 years (range 16 to 22 years). Tannerella forsythia (1.5 × 10⁵) and Veillonella parvula (1.02 × 10⁵) showed the highest concentrations around implants and teeth, respectively. Porphyromonas gingivalis, Prevotella intermedia, and T. forsythia were significantly more present around implants than teeth. Mean counts were significantly higher around implants than teeth for Parvimonas micra, P. gingivalis, P. intermedia, T. forsythia, and Treponema denticola. Total DNA count was correlated to interproximal bleeding index (r = 0.409) and interproximal probing depth (r = 0.307). No correlations were present with plaque index or radiographic bone level. Conclusions: In the present study, bacterial counts around single implants in periodontally healthy patients are rather low. Although pathogenic bacteria are present, some in higher numbers around implants than teeth (five of 40), the majority of implants present with healthy peri‐implant tissues without progressive bone loss.     

Effect of Flapless Surgery on Single‐Tooth Implants in the Esthetic Zone: A Randomized Clinical Trial

Background: Implant therapy is a highly predictable treatment option; however, insufficient data exist to show whether flapless implant surgery provides better esthetic outcomes and less bone loss than implant surgery with a flap approach. Methods: In this randomized, controlled study comparing the flapless and traditional flap protocol for implant placement, 24 patients received a single implant in the anterior maxillary region. A cone beam computed tomography–aided surgical guide was used for implant placement surgery for both groups. Implants were restored using a one‐piece, screw‐retained ceramic crown at 3 months. Radiographic and clinical measurements were assessed at baseline (implant placement) and at 3 (crown placement), 6, 9, and 15 months. Clinical parameters evaluated were plaque index, gingival index, papillary index (PPI) (0 = no papilla, 1 = less than half, 2 = more than half but not complete, 3 = complete fill, and 4 = overfill), marginal tissue levels, biotype, width of keratinized tissue, and soft tissue thickness. Results: Implant success rate was 92% in both groups. Mean PPI values for the flap control group and flapless test group were 2.38 ± 0.51 versus 2.31 ± 0.48 at crown placement (P = 0.68) and 2.52 ± 0.52 versus 2.64 ± 0.54 at 15 months (P = 0.42), respectively. PPI increased over time in both groups, although the flapless group had a significantly larger change in PPI from crown placement to 6 and 9 months (P <0.01). Crestal bone levels in the flap group were more apical in relation to the implant platform than those in the flapless group for the duration of the study. No differences among groups were noted for all other measurements. Conclusions: Both flapless and flap implant placement protocols resulted in high success rates. A flapless protocol may provide a better short‐term esthetic result, although there appears to be no long‐term advantage.     

临时冠单体释出对颊黏膜上皮细胞DNA损伤的影响

目的研究4种临时冠桥材料戴用后的单体释出对颊黏膜上皮细胞DNA损伤的影响。方法给狗的右侧后牙进行全冠牙体预备后,分别选用4种临时冠桥材料(自凝塑料、热凝塑料、DMG-TEMP树脂、松风SWIFT-TEMP树脂)进行临时冠修复。在牙备前、戴冠时及戴冠后1周、2周、1个月5个时期,收集临时冠对应区域的颊黏膜上皮细胞,应用单细胞凝胶电泳(彗星实验)检测颊黏膜上皮细胞的DNA损伤程度。结果自凝塑料组及热凝塑料组临时冠戴用后,颊黏膜上皮细胞的彗星百分率在戴冠1周>戴冠2周>戴冠1月>牙备前和戴冠时,存在显著性差异(P<0.01)。空白对照组、DMG-TEMP树脂组及松风SWIFT-TEMP树脂组的颊黏膜上皮细胞的彗星百分率在戴冠前、后均维持较低水平,无统计学差异(P>0.05)。颊黏膜上皮细胞的DNA损伤程度(以彗星百分率反应)与临时冠材料中的有机叔胺及MMA单体的释出量呈正相关性。结论自凝塑料及热凝塑料临时冠在戴冠后的早期均有残余单体释出,并导致对应区域颊黏膜上皮细胞的DNA损伤。DMG-TEMP树脂及松风SWIFT-TEMP树脂临时冠戴用后,未有显著的颊黏膜上皮细胞的DNA损伤。     

CAD/CAM氧化锆及Empress全瓷冠修复三年临床效果比较

目的:比较CAD/CAM氧化锆及Empress全瓷冠修复3年的临床效果。方法:选择350例患者共838个全冠修复体(其中CAD/CAM氧化锆全冠428颗、Empress铸瓷全冠410颗),平均观察期36.2±5月,随访检查基牙和修复体情况,分别对两组全瓷冠的存留率和修复成功率进行统计学分析。结果:观察期内共有41颗全瓷冠(19颗为氧化锆,22颗为Empress铸瓷)完全失败,需重新制作。氧化锆全瓷冠和Empress铸瓷全冠的存留率分别为95.1%和95.8%,成功率分别为90.7%和91.2%,其差异均无统计学意义。结论:CAD/CAM氧化锆和Empres铸瓷全冠均能满足临床需要,有较好的修复效果。     

Orthodontic parotitis: a rare complication from an orthodontic appliance

Abstract

A case is presented of a 14-year-old female undergoing orthodontic fixed appliance treatment who presented with right facial swelling in the parotid region. An initial diagnosis of acute infective parotitis was made by her primary care clinician. However, after clinical examination and ultrasonographic imaging, a diagnosis of salivary stasis secondary to inflammatory occlusion of Stensen’s ductal orifice was made. The ductal orifice had been traumatized by the adjacent orthodontic appliance. This has not been described before in the literature. The differential diagnosis of parotid enlargement in children is discussed.     

COMTval158met基因多态性对患者术前焦虑和疼痛敏感性的影响

目的 探讨COMTval158met基因多态性对患者术前焦虑和疼痛敏感性的影响.方法 择期手术患者284例,性别不限,年龄20～ 50岁,体重指数在正常范围,ASA分级Ⅰ或Ⅱ级;另取健康志愿者28名,年龄18 ～ 25岁,体重指数在正常范围.采用苯酚-氯仿萃取法提取DNA.采用聚合酶链式反应-限制性片段长度多态性法进行COMTval158met基因多态性检测.根据患者和健康志愿者基因型分组:野生型纯合子组(G/G组)、突变型杂合子组(G/A组)和突变型纯合子组(A/A组).手术或试验前1d进行焦虑状态评分(SAI评分)和焦虑特质评分(TAI评分);患者或健康志愿者入室后平静10 min,采用电刺激仪测定痛阈与耐痛阈.结果 患者G/G组132例,G/A组110例,A/A组42例.健康志愿者G/G组12名,G/A组11名,A/A组5名.COMTval158met等位基因A突变频率为34.5％.健康志愿者3个基因组痛阈、耐痛阈、SAI评分和TAI评分比较差异无统计学意义(P＞0.05);与G/G组比较,患者A/A组痛阈、耐痛阈降低,SAI评分和TAI评分升高(P＜0.05),G/A组上述指标差异无统计学意义(P＞0.05);与健康志愿者比较,患者G/G组和G/A组SAI评分升高,A/A组痛阈、耐痛阈降低,SAI评分升高(P＜0.05).患者COMTval158met等位基因A与耐痛阈、痛阈呈负相关,与术前SAI评分呈正相关(P＜0.05).结论 COMT val158 met基因多态性与患者术前焦虑程度显著相关,以致引起患者疼痛敏感性增强.     

非HLA基因单核苷酸多态性对造血干细胞移植后巨细胞病毒感染的影响

目的 探讨非HLA基因单核苷酸多态性(SNP)对造血干细胞移植后巨细胞病毒(CMV)感染的影响.方法 对2008年7月至2011年12月接受异基因造血干细胞移植的受者及其相应供者64例进行研究.采用聚合酶链反应-序列特异性寡核苷酸探针和测序方法检测髓过氧化物酶基因(MPO)、甘露糖结合凝集素基因(MBL)、CD14基因和血管紧张素转换酶(ACE)基因的SNP,结合CMV pp65检测结果,比较CMV阳性组和CMV阴性组ACE、CD14、MPO、MBL基因SNP的差异.结果 ACE 16内含子基因多态性分布:DD型14例(10.9％),ID型72例(56.3％),Ⅱ型42例(38.8％);CD14-159位基因多态性分布:CC型18例(14.1％),CT型81例(63.3％),TT型29例(22.7％);MPO-463位点基因多态性分布:G型100例(78.1％),A型2例(1.6％),GA型26例(20.3％);MBL启动子-550位基因多态性分布:H型28例(21.9％),HL型73例(57.0％),L型27例(21.1％);MBL启动子-221位基因多态性分布:Y型87例(68.0％),YX型38例(29.7％),X型3例(2.3％);MBL外显子1区基因多态性分布:A型94例(73.4％),AB型32例(25.0％),B型2例(1.6％).CMV阳性组和CMV阴性组供、受者ACE、CD14-159位点、MPO-463位点、MBL启动子-221以及外显子1区基因单核苷酸多态性相比较,差异均无统计学意义;但CMV阳性组供者MBL-550位点HL基因频率明显增高,与阴性组比较,差异有统计学意义.结论 供者MBL的单核苷酸多态性对造血干细胞移植后CMV感染有影响.     

Prevention of mother-to-child transmission of human immunodeficiency virus among pregnant women using injecting drugs in Ukraine, 2000-10

Aims To compare clinical status, mother‐to‐child transmission (MTCT) rates, use of prevention of (PMTCT) interventions and pregnancy outcomes between HIV‐infected injecting drug users (IDUs) and non‐IDUs. Design and setting Prospective cohort study conducted in seven human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) Centres in Ukraine, 2000–10. Participants Pregnant HIV‐infected women, identified before/during pregnancy or intrapartum, and their live‐born infants (n = 6200); 1028 women followed post‐partum. Measurements Maternal and delivery characteristics, PMTCT prophylaxis, MTCT rates, preterm delivery (PTD) and low birth weight (LBW). Findings Of 6200 women, 1111 (18%) reported current/previous IDU. The proportion of IDUs diagnosed with HIV before conception increased from 31% in 2000/01 to 60% in 2008/09 (P < 0.01). Among women with undiagnosed HIV at conception, 20% of IDUs were diagnosed intrapartum versus 4% of non‐IDUs (P < 0.01). At enrolment, 14% of IDUs had severe/advanced HIV symptoms versus 6% of non‐IDUs (P < 0.001). IDUs had higher rates of PTD and LBW infants than non‐IDUs, respectively, 16% versus 7% and 22% versus 10% (P < 0.001). IDUs were more likely to receive no neonatal or intrapartum PMTCT prophylaxis compared with non‐IDUs (OR 2.81, p < 0.001). MTCT rates were 10.8% in IDUs versus 5.9% in non‐IDUs; IDUs had increased MTCT risk (adjusted odds ratio 1.32, P = 0.049). Fewer IDUs with treatment indications received HAART compared with non‐IDUs (58% versus 68%, P = 0.03). Conclusions Pregnant human immunodeficiency virus‐infected injecting drug users in Ukraine have worse clinical status, poorer access to prevention of mother‐to‐child transmission prophylaxis and highly active antiretroviral therapy, more adverse pregnancy outcomes and higher risk of mother‐to‐child transmission than non‐injecting drug user women.