水激光与超声洁治对中度慢性牙周炎的疗效对比

目的:探讨水激光与超声洁治对中度慢性牙周炎的疗效。方法:选取81例中度慢性牙周炎患者,年龄27-62岁,随机分为两组:激光组(41例)采用水激光治疗,超声组(40例)采用超声洁治法治疗。通过患者治疗后1个月,3个月的菌斑指数(plaque index,PLI),牙龈指数(gingival index,GI),牙周袋深度(probing depth,PD),牙周附着水平(clinical attachment level,CAL),治疗过程中的VAS评分等观察指标,对水激光与超声洁治进行疗效对比。结果:与基线各项牙周指数相比,激光组和超声组治疗后1个月,3个月的各项牙周指数均明显降低(P0.05)。与超声组相比,激光组治疗后1个月的GI值明显低于超声组,治疗后1个月和3个月的PD值和CAL值均低于超声组(P0.05)。治疗前,两组VAS评分相比,差异没有统计学意义(P0.05),治疗后,激光组的VAS评分明显低于超声组(P0.05)。结论:水激光治疗中度慢性牙周炎,治疗过程痛觉感受轻微,能轻易清除引起炎症的牙石及菌斑,促进牙周组织愈合。     

Impaired neutrophil extracellular trap formation: a novel defect in the innate immune system of aged individuals

Neutrophil extracellular traps (NETs) are a recently discovered addition to the defensive armamentarium of neutrophils, assisting in the immune response against rapidly dividing bacteria. Although older adults are more susceptible to such infections, no study has examined whether aging in humans influences NET formation. We report that TNF‐α‐primed neutrophils generate significantly more NETs than unprimed neutrophils and that lipopolysaccharide (LPS)‐ and interleukin‐8 (IL‐8)‐induced NET formation exhibits a significant age‐related decline. NET formation requires generation of reactive oxygen species (ROS), and this was also reduced in neutrophils from older donors identifying a mechanism for reduced NET formation. Expression of IL‐8 receptors (CXCR1 and CXCR2) and the LPS receptor TLR4 was similar on neutrophils from young and old subjects, and neutrophils challenged with phorbol‐12‐myristate‐13‐acetate (PMA) showed no age‐associated differences in ROS or NET production. Taken together, these data suggest a defect in proximal signalling underlies the age‐related decline in NET and ROS generation. TNF‐α priming involves signalling through p38 MAP kinase, but activation kinetics were comparable in neutrophils from young and old donors. In a clinical setting, we assessed the capacity of neutrophils from young and older patients with chronic periodontitis to generate NETs in response to PMA and hypochlorous acid (HOCL). Neutrophil extracellular trap generation to HOCL, but not PMA, was lower in older periodontitis patients but not in comparison with age‐matched controls. Impaired NET formation is thus a novel defect of innate immunity in older adults but does not appear to contribute to the increased incidence of periodontitis in older adults.     

牙周基础治疗和牙周再生术联合正畸治疗对广泛型侵袭性牙周炎合并牙槽骨缺损患者的临床研究

摘要 目的：观察牙周基础治疗和牙周再生术联合正畸治疗对广泛型侵袭性牙周炎合并牙槽骨缺损患者的临床疗效及对血清炎症因子和牙龈沟细菌微生态的影响。方法：分析我院2017年8月~2018年8月期间接收的83例广泛型侵袭性牙周炎合并牙槽骨缺损患者的临床资料。根据治疗方式的不同将患者分为A组（40例,牙周基础治疗和牙周再生术治疗）和B组（43例,牙周基础治疗和牙周再生术联合正畸治疗）。观察两组疗效、血清炎症因子、牙龈沟细菌微生态、牙周指标及牙槽骨密度、牙槽骨缺损高度。结果：B组的临床总有效率高于A组（P<0.05）。B组治疗结束后龈沟出血指数（SBI）、牙周探诊深度（PD）、临床附着丧失（AL）、牙菌斑指数（PLI）、牙龈指数（GI）低于A组（P<0.05）。B组治疗结束后牙槽骨缺损高度低于A组,牙槽骨密度高于A组（P<0.05）。B组治疗结束后血清白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、白介素-8（IL-8）水平低于A组（P<0.05）。B组治疗结束后杆菌、球菌、丝状菌、弯曲菌检出率低于A组,梭状菌、螺旋体检出率高于A组（P<0.05）。结论：广泛型侵袭性牙周炎合并牙槽骨缺损患者采用牙周再生术、牙周基础治疗联合正畸治疗,疗效显著,可有效改善牙周状况及牙槽骨缺损情况,降低血清炎症因子水平,但该联合治疗方案会对口腔的细菌微生态产生破坏作用。因此,在接受该方案治疗时,应注意口腔清洁,尽量减轻对牙龈沟细菌微生态的影响。     

Single nucleotide polymorphisms associated with aggressive periodontitis and severe chronic periodontitis in Japanese

Periodontitis is a common inflammatory disease causing destruction of periodontal tissues. It is a multifactor disease involving genetic factors and oral environmental factors. To determine genetic risk factors associated with aggressive periodontitis or severe chronic periodontitis, single nucleotide polymorphisms (SNPs) in multiple candidate genes were investigated in Japanese. We studied 134 patients with aggressive periodontitis, 117 patients with severe chronic periodontitis, and 125 healthy volunteers without periodontitis, under case-control setting, and 310 SNPs in 125 candidate genes were genotyped. Association evaluation by Fisher's exact test (p < 0.01) revealed statistically significant SNPs in multiple genes, not only in inflammatory mediators (IL6ST and PTGDS, associated with aggressive periodontitis; and CTSD, associated with severe chronic periodontitis), but also in structural factors of periodontal tissues (COL4A1, COL1A1, and KRT23, associated with aggressive periodontitis; and HSPG2, COL17A1, and EGF, associated with severe chronic periodontitis). These appear to be good candidates as genetic factors for future study.     

Reduced ELANE and SLPI expression compromises dental pulp cell activity

BackgroundPatients with ELANE variants and severe congenital neutropenia (SCN) commonly develop oral complications. Whether they are caused only by low neutrophil count or the combination of neutropenia and aberrant dental cells is unknown.MethodsGenetic variant was identified with exome sequencing. Dental pulp cells isolated from the SCN patient with an ELANE mutation were investigated for gene expression, enzyme activity, proliferation, colony formation, wound healing, apoptosis, ROS, attachment, spreading and response to lipopolysaccharide.ResultsELANE cells had diminished expression of ELANE and SLPI and reduced neutrophil elastase activity. Moreover, ELANE cells exhibited impaired proliferation, colony forming, migration, attachment and spreading; and significantly increased ROS formation and apoptosis, corresponding with increased Cyclin D1 and MMP2 levels. The intrinsic levels of TGF‐β1 and TNF‐α were significantly increased; however, IL‐6, IL‐8 and NF‐kB1 were significantly decreased in ELANE cells compared with those in controls. After exposure to lipopolysaccharide, ELANE cells grew larger, progressed to more advanced cell spreading stages and showed significantly increased SLPI, TNF‐α and NF‐kB1 and tremendously increased IL‐6 and IL‐8 expression, compared with controls.ConclusionThis study, for the first time, suggests that in addition to neutropenia, the aberrant levels and functions of ELANE, SLPI and their downstream molecules in pulp cells play an important role in oral complications in SCN patients. In addition, pulp cells with diminished neutrophil elastase and SLPI are highly responsive to inflammation.     

Isolation of bacteriophages from the oral cavity

AIMS: To isolate bacteriophages lytic for oral pathogens from human saliva, dental plaque and mature biofilms constituted from saliva-derived bacteria. METHODS AND RESULTS: Saliva and dental plaque samples from healthy volunteers and from patients with gingivitis and periodontitis were examined for the presence of lytic bacteriophage using a panel of oral pathogens and bacteria isolated from the samples. Samples were also enriched for bacteriophage using static culture techniques and mature biofilms. A limited number of samples contained bacteriophage particles that were visualized using electron microscopy. Cultures yielded phage infecting non-oral bacteria (Proteus mirabilis) but no bacteriophage specific for recognized oral pathogens were found. Some micro-organisms from the oral microflora elaborated antibacterial substances that inhibited growth of other residents of the oral cavity. CONCLUSIONS: Unlike other ecosystems, the composition of the oral cavity does not appear to be heavily influenced by interactions between bacteriophages and their hosts. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriophage for control of oral infections may need to be obtained from other sources. Antibacterial substances derived from some members of the oral microflora warrant investigation as potential antibiotics.     

Detection of Tannerella forsythia and/or Prevotella intermedia might be useful for microbial predictive markers for the outcome of initial periodontal treatment in Koreans

A proportion of diseased sites in periodontal disease do not respond to the initial treatment, which might be due in part to the presence of specific microbial pathogens. The aim of this study was to clarify the value of microbial screening for predicting the outcome of periodontal treatment in Koreans using a polymerase chain reaction (PCR). This study enrolled 32 adults with periodontal disease. Microbial and clinical examinations were performed at the baseline and after the initial treatment (professional toothbrushing, scaling, and root planing). Subgingival plaque samples were taken from four sites in each subject (total 128 samples). PCR was used to detect the four putative pathogenic bacteria. There was an improvement in the average of each clinical measurement after the initial treatment. However, approximately half of the sites exhibiting bleeding upon probing (BOP) at the baseline still exhibited bleeding after treatment. There was a close association between the presence of BOP and the presence of Tannerella forsythia (formerly Bacteroides forsythus) and/or Prevotella intermedia. Furthermore, the sites harboring both T. forsythia and P. intermedia at the baseline had a poorer response to treatment than the sites where these two species were not detected. Therefore, microbial screening for T. forsythia and P. intermedia might be useful for predicting the treatment outcome in Koreans.     

Existence of natural mouse IgG mAbs recognising epitopes shared by malondialdehyde acetaldehyde adducts and Porphyromonas gingivalis

Natural Abs are produced by B lymphocytes in the absence of external Ag stimulation. They recognise self, altered self and foreign Ags, comprising an important first-line defence against invading pathogens and serving as innate recognition receptors for tissue homeostasis. Natural IgG Abs have been found in newborns and uninfected individuals. Yet, their physiological role remains unclear. Previously, no natural IgG Abs to oxidation-specific epitopes have been reported. Here, we show the cloning and characterisation of mouse IgG mAbs against malondialdehyde acetaldehyde (MAA)-modified low-density lipoprotein. Sequence analysis reveals high homology with germline genes, suggesting that they are natural. Further investigation shows that the MAA-specific natural IgG Abs cross-react with the major periodontal pathogen Porphyromonas gingivalis and recognise its principle virulence factors gingipain Kgp and long fimbriae. The study provides evidence that natural IgGs may play an important role in innate immune defence and in regulation of tissue homeostasis by recognising and removing invading pathogens and/or modified self-Ags, thus being involved in the development of periodontitis and atherosclerosis.     

Quorum sensing in biofilms--how to destroy the bacterial citadels or their cohesion/power?

Biofilms or microbial communities formed by adherent and cohesive cells on cellular or inert substrata (like medical devices), are involved in ∼60% of all infections and characterized by moderate intensity symptoms, chronic evolution and resistance to antibiotics. Biofilms’ pathogenicity, even of those formed by opportunistic microorganisms, is amplified by two major biofilm characteristics: 1) the increased resistance to antimicrobials; 2) the protection of cells against the host’s defence mechanisms. The studies at the molecular level shown that the biofilms formation is controlled by cell-to-cell signalling mechanisms and the gene regulation during biofilm growth is due to the accumulation of signal molecules. In this regard, quorum sensing mechanism (QS) is defined as a cell-density dependent bacterial intercellular communication, involved in gene expression (e.g. virulence genes for exoenzymes, exopolysaccharides) and the consequent changed behaviour of biofilm’s cells, including the resistance to stress conditions; this resistance is different of well known antibioresistance, being named phenotypical resistance or tolerance. Considering the differences in physiology and susceptibility to antibiotics of biofilm embedded bacteria, as well as their increased power against the host defence responses, there are necessary new strategies for prevention and therapy of biofilm associated infections. The dental plaque is a typical example of biofilm, involved in the ethiology of cariogenesis and periodontal diseases associated with local chronic inflammation and cytokines production. The genetical and phenotypical versatility of the biofilm’s cells represent a challenge for discovering new methods of treatment and prevention of biofilm associated infections. A novel class of antibiofilm and antipathogenic therapeutics which are interfering with a new target – the QS pathway, not based on growth inhibition and called QS inhibitors, natural, with different origins or artificial, are now developing as an alternative to antibiotherapy.