A model for assisted ion transfer across liquid ∣ liquid interfaces

Ion transfer through a liquid ∣ liquid interface can be enhanced considerably by complexation with a suitable ionophore. Here we consider the case in which this complexation occurs at the interface. From a simple lattice-gas model we calculate the potential of mean force and the density profiles for the particles involved in the reaction. A change in the potential difference between the two phases affects the concentration of the ions at the interface, but does not change the driving force for the complexation. The rate of ion transfer depends roughly exponentially on the potential.     

A non‐staining chlorhexidine mouthwash? Probably not: a study in vitro

Background and aim: Tooth staining is a common side effect of chlorhexidine mouth rinses and caused by the interaction of the di‐cationic antiseptic with dietary chromogens. A product is now available, which claims an anti‐discolouration system (ADS) with one clinical study in support. This study in vitro aims to determine whether two ADS rinses do or do not bind dietary chromogens. Method and materials: Optically clear acrylic specimens were cycled through human saliva (2 min), one of the three chlorhexidine rinses (two ADS and a positive control) (2 min) or water and then soaked in tea (60 min). After each cycle the optical density (OD) of specimens were read on a UV/visible spectrophotometer. The exit point was the cycle at which OD was >2.0. Results: All three rinses exceeded OD 2 at 11 cycles and there was no significant difference in staining for the ADS rinses compared with the positive control rinse. Conclusion: Based on extensive literature for the correlation of this test in vitro with chlorhexidine anti‐plaque activity and propensity to stain in vivo these ADS rinses will have the same anti‐plaque efficacy and potential to cause stain as established chlorhexidine rinse products.     

Dental erosion – changing prevalence? A review of British national childrens’ surveys

Summary. Objectives. To investigate the change in the prevalence of dental erosion, over time, by a review of the data from the published national dental surveys of young people in the UK. A subsidiary objective was to investigate the relationship between erosion and possible associated risk factors. Design. The review was based on cross‐sectional prevalence studies incorporating a clinical dental examination and structured interviews. Sample. The data were collated from the 1993 UK childrens’ dental health survey and the dental report of the two National Diet and Nutrition Surveys (NDNS) of children aged 1½?4½ in 1992/3 and 4–18 years in 1996/7. The criteria used for data collection were comparable between the three different studies. Results. Comparing the data from the different studies, the prevalence of erosion was seen to increase from the time of the childrens’ dental health survey in 1993 and the NDNS study of 4–18‐year‐olds in 1996/7. There was a trend towards a higher prevalence of erosion in children aged between 3½ and 4½ and in those who consumed carbonated drinks on most days compared with toddlers consuming these drinks less often. Drinks overnight were associated with an increased prevalence of erosion. More 4–6‐year‐olds with reported symptoms of gastro‐oesophageal reflux had erosion compared with symptom‐free children. On multivariate analysis, the strongest independent association with erosion was geography, with children living in the North having twice the odds of having erosion compared with those in London and the South‐east. Conclusions. Comparing prevalence data from cross‐sectional national studies indicates that dental erosion increases between different age cohorts of young people over time. Dietary associations with erosion are present but weak. Similarly, there is an association apparent between erosion, symptoms of gastro‐oesophageal reflux and socio‐demographic variables such as region of domicile, social class, and receipt of social benefits.     

Can Peri‐Implant Crevicular Fluid Assist in the Diagnosis of Peri‐Implantitis? A Systematic Review and Meta‐Analysis

Background: A broader understanding of the immune inflammatory profile of peri‐implant diseases could be helpful in the development of host‐targeted preventive and therapeutic strategies. The aim of this study is to answer two clinical questions: 1) whether patients with peri‐implantitis (PP) present higher prevalence of any specific inflammatory cytokine in peri‐implant crevicular fluid (PICF) compared with healthy patients; and 2) whether local inflammation measured in PICF can be used as a predictor for incipient PP. Methods: A systematic review of the literature on the most common cytokines released in PICF in healthy and PP‐affected sites was conducted from 1996 up to and including October 2013 using predefined search strategies. Cross‐sectional and prospective longitudinal studies were considered. Meta‐analyses were done separately for healthy, mucositis (MU), and PP outcomes. Results: Interleukin (IL)‐1β was the most studied cytokine (n = 12), followed by tumor necrosis factor (TNF)‐α (n = 10). Other cytokines were also linked to PP, such as IL‐4, IL‐6, IL‐8, IL‐10, IL‐12, and IL‐17. Statistical differences were revealed when IL‐1β release was compared between healthy implant sites and PP (P = 0.001) or MU sites (P = 0.002), respectively; when PP and MU were compared, no statistical differences could be detected (P = 0.80). For TNF‐α release, significant differences were found between healthy and PP implants (P = 0.02). Conclusions: PICF containing inflammatory mediators, such as IL‐1β and TNF‐α, can be used as additional criteria for a more robust diagnosis of peri‐implant infection. Additionally, once the inflammatory process is installed, no differences were found between peri‐implant MU and PP.     

嵌合体SBR-CT~(ΔA1)植物表达质粒的构建

目的　构建含编码嵌合体SBR-CTΔA1基因的植物表达质粒。方法　用PCR扩增的含编码嵌合体 SBR-CTΔA1基因的P2片段(3 498~5 378 bp),经TA克隆与pGEM-easy载体结合得到pTSC质粒,pTSC质粒经BamHⅠ 和KpnⅠ双酶切后得到P2片段,P2片段与BamHⅠ和KpnⅠ双酶切后的植物高效表达质粒pPOKⅡ定向克隆,构建 pROSC表达质粒;且将此质粒与bar基因(抗除草剂基因)连接,构建重组质粒pROSB,并经酶切电泳及DNA序列测定鉴定。结果　含编码嵌合体SBR-CTΔA1基因的P2片段整合到pPOKⅡ的适当部位,插入相位正确,未改变目的基因的阅读框架;从pBARGUS分离出的bar基因整合到pROSC,构成重组质粒pROSB。结论　本实验成功构建了携带编码嵌合体SBR-CTΔA1基因的植物表达质粒pROSC和pROSB。     

A survey of oral surgeons’ tobacco-use-related knowledge and intervention behaviors

Objectives: To evaluate whether oral surgeons are aware of tobacco’s role in oral health. Moreover, we wanted to know professionals’ attitudes towards smoker patients and physicians’ involvement in detecting and eradicating this habit in patients. Study Design: We conducted a survey to determine the awareness of the members of the Spanish Society of Oral Surgery about tobacco’s damage on oral health and the role of dentists in the prevention and elimination of the smoking habit. Results: 450 surveys were distributed during the Seventh National Congress of the Spanish Society of Oral Surgery, of which 224 (49.8%) were answered. Seventy-six point eight percent of oral surgeons said that they have a good knowledge of the effects of snuff on oral health. However, only 42.9% admitted they had received specific training regarding how to deal with patients who want to give up smoking. Sixty-three point four percent had explained to smoker patients the risk of this habit for the oral and general health. However, 17% admitted they do not advise their patients to give up smoking for fear of upsetting them, while 15.2% expressed lack of time, and 3.6% think it is not their competence. As to the relationship between oral cancer and smoking, 83% of oral surgeons recognize a direct relationship. In addition, 85.7% of professionals believe that dentists have a primary role in oral cancer prevention. Conclusions: These results indicate that most oral surgeons are concerned about the smoking habit of their patients. However, it is necessary to increase the specific training of dentists by providing tobacco treatment programs as part of their professional responsibility. Oral surgeons recognize the direct relationship between the smoking habit and oral cancer and regard as very important the role of dentists in the prevention of this disease. Key words:Smoking habit, oral surgery, oral cancer.     

Are Short Dental Implants (<10 mm) Effective? A Meta‐Analysis on Prospective Clinical Trials

Background: This study aims to compare the survival rate of short (<10 mm) and standard (≥10 mm) rough‐surface dental implants under functional loading. Methods: An electronic literature search using PubMed and Medline databases was conducted. Prospective clinical human trials, published in English from January 1997 to July 2011, that examined dental implants of <10 mm with a 12‐month follow‐up were included in this meta‐analysis. The following data were retrieved from the included articles: the number of implants, implant dimensions, implant locations, types of prostheses, follow‐up periods, and implant survival rates. Kaplan‐Meier survival estimates and the hazard rates were analyzed and compared between short and standard implants. Results: Thirteen studies were selected, examining 1,955 dental implants, of which 914 were short implants. Short dental implants had an estimated survival rate of 88.1% at 168 months, when standard dental implants had a similar estimated survival rate of 86.7% (P = 0.254). The peak failure rate of short dental implants was found to occur between 4 and 6 years of function. This occurred at an earlier time point compared with standard dental implants, where the peak failure rate occurred between 6 and 8 years of function. Conclusions: This study shows that in the long term, implants of <10 mm are as predictable as longer implants. However, they fail at an earlier stage compared with standard implants.     

L’analyse morphologique céphalométrique : que peut-elle nous enseigner ?

Cephalometric analysis is an invaluable tool for orthodontists in the diagnosis and treatment planning of their patients. This article discusses the history, development and application of the Björk cephalometric analysis. The advantages and disadvantages of the conventional analysis are discussed and the benefits of using a limited number of parameters are emphasized.