Depth-force-patterns in periodontal probing

This investigation was undertaken to study penetration-depth and simultaneous force development during the insertion of a standard periodontal probe tip into a pocket to gain information about the tissue resistance to probing and its relation to the accuracy of depth determination. A piezoelectric force transducer and a linear position transducer were incorporated into a periodontal probe. Depth-force diagrams were obtained on an x-y plotter. In 5 patients requiring treatment for chronic periodontitis, 50 sites were selected and measured 3 times before and 3 times after a treatment phase consisting of hygiene instruction, systematic deep scaling and root planing. The minimal required probing force for reproducible values within a limit of 0.5 mm up to a force of 1.2 N was determined for each record ("b-value") and correlated in a multiple linear regression analysis with a number of clinical parameters of the sites. Depth-force diagrams recorded with the probe showed the characteristics of saturation curves flattening off in the range of 1 N and more. When the probing force was increased from 0.41 N up to 1.2 N, 50% of all measurements showed an increase in depth of more than 0.5 mm. However, increasing from 0.9 to 1.2 N resulted in a change of more than 0.5 mm in only 5% of the measurements. Differences in b-values before and after the treatment were significant (p less than 0.01). Differences related to tooth type (M, PM, I) and conventional pocket depth before treatment were also significant (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults

The aim of this study was to determine the presence or absence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults and to examine the A. actinomycetemcomitans isolates from positive subjects with regard to the serotype distribution, presence of the leukotoxin gene lktA and the promoter for the leukotoxin operon as well as the incidence of phage Aa phi 23. Sixty subjects, working in a knitting factory in the Province of Guangzhou, People's Republic of China, were investigated. Subgingival microbial samples were taken from both upper first molars. They were cultured both anaerobically and in 5% CO2. P. gingivalis was found in 33 subjects. On average, it constituted 7% of the total anaerobic cultivable counts. A. actinomycetemcomitans was detected in 37 subjects of which seven yielded counts > 10(5). Twenty-one subjects were positive for both organisms. A. actinomycetemcomitans serotype a was found in 9 subjects, serotype c was found in 23 and serotype e in 5. A. actinomycetemcomitans serotypes b and d were not detected in any subjects. Presence of the leukotoxin gene lktA was demonstrated for all A. actinomycetemcomitans isolates; however, none of the A. actinomycetemcomitans strains from the present study had a deletion in the promoter region of the leukotoxin operon. The results of this investigation show a high frequency of the putative periodontal pathogens P. gingivalis and A. actinomycetemcomitans and corroborate the concept that there is variation in virulence and pathogenic potential among isolates from different subjects.     

Burden,epidemiology, and outcomes of microbiologically confirmed respiratory viral infections in solid organ transplant recipients: a nationwide,multi-season prospective cohort study

Solid organ transplant (SOT) recipients are exposed to respiratory viral infection (RVI) during seasonal epidemics; however, the associated burden of disease has not been fully characterized. We describe the epidemiology and outcomes of RVI in a cohort enrolling 3294 consecutive patients undergoing SOT from May 2008 to December 2015 in Switzerland. Patient and allograft outcomes, and RVI diagnosed during routine clinical practice were prospectively collected. Median follow-up was 3.4 years (interquartile range 1.61–5.56). Six hundred ninety-six RVIs were diagnosed in 151/334 (45%) lung and 265/2960 (9%) non-lung transplant recipients. Cumulative incidence was 60% (95% confidence interval [CI] 53%-69%) in lung and 12% (95% CI 11%-14%) in non-lung transplant recipients. RVI led to 17.9 (95% CI 15.7–20.5) hospital admissions per 1000 patient-years. Intensive care unit admission was required in 4% (27/691) of cases. Thirty-day all-cause case fatality rate was 0.9% (6/696). Using proportional hazard models we found that RVI (adjusted hazard ratio [aHR] 2.45; 95% CI 1.62–3.73), lower respiratory tract RVI (aHR 3.45; 95% CI 2.15–5.52), and influenza (aHR 3.57; 95% CI 1.75–7.26) were associated with graft failure or death. In this cohort of SOT recipients, RVI caused important morbidity and may affect long-term outcomes, underlying the need for improved preventive strategies.     

Anti-infective treatment of peri-implant mucositis: a randomised controlled clinical trial

Aim: To compare the effectiveness of two anti‐infective protocols for the treatment of peri‐implant mucositis. Materials and methods: Twenty‐nine patients with one implant diagnosed with peri‐implant mucositis (bleeding on probing [BOP] with no loss of supporting bone) were randomly assigned to a control or test group. Following an assessment of baseline parameters (probing depth, BOP, suppuration, presence of plaque), all patients received non‐surgical mechanical debridement at the implant sites and were instructed to brush around the implant twice daily using a gel provided for a period of 4 weeks. The test group (15 patients) received a chlorhexidine gel (0.5%), and the control group (14 patients) received a placebo gel. The study was performed double blind. After 4 weeks, patients were instructed to discontinue using the gel and to continue with routine oral hygiene at the implant sites. Baseline parameters were repeated at 1 and 3 months. Results: At 1 month, there was a statistically significant reduction in the mean number of sites with BOP and mean probing depth measurements at implants in both groups. There were also some statistically significant changes in these parameters from 1 to 3 months. However, there were no statistically significant differences between test and control groups. One month following treatment, 76% of implants had a reduction in BOP. Complete resolution of BOP at 3 months was achieved in 38% of the treated implants. The presence of a submucosal restoration margin resulted in significantly lower reductions in probing depth following treatment. Conclusions: Non‐surgical debridement and oral hygiene were effective in reducing peri‐implant mucositis, but did not always result in complete resolution of inflammation. Adjunctive chlorhexidine gel application did not enhance the results compared with mechanical cleansing alone. Implants with supramucosal restoration margins showed greater therapeutic improvement compared with those with submucosal restoration margins. To cite this article:
Heitz‐Mayfield LJA, Salvi GE, Botticelli D, Mombelli A, Faddy M, Lang NP, On Behalf of the Implant Complication Research Group (ICRG). Anti‐infective treatment of peri‐implant mucositis: a randomised controlled clinical trial.
Clin. Oral Impl. Res. 22 , 2011; 237–241.
doi: 10.1111/j.1600‐0501.2010.02078.x     

Clinical response to statins: mechanism(s) of variable activity and adverse effects

Statins represent a major advance in the treatment of hypercholesterolemia, a significant risk factor for atherosclerosis. There is, however, notable interindividual variation in the cholesterolemic response to statins, and the origin of this variability is poorly understood; pharmacogenetics has attempted to determine the role of genetic factors. Myopathy, further, has been reported in a considerable percentage of patients, but the mechanisms underlying muscle injury have yet to be fully characterized. Most statins are the substrates of several cytochrome P450s (CYP). CYP polymorphisms may be responsible for variations in hypolipidemic activity; inhibitors of CYPs, e.g. of CYP3A4, can significantly raise plasma concentrations of several statins, but consequences in terms of clinical efficacy are not uniform. Pravastatin and rosuvastatin are not susceptible to CYP inhibition but are substrates of the organic anion-transporting polypeptide (OATP) 1B1, encoded by the SLCO1B1 gene. Essentially all statins are, in fact, substrates of membrane transporters: SLCO1B1 polymorphisms can decrease the liver uptake, as well as the therapeutic potential of these agents, and may be linked to their muscular side-effects. A better understanding of the mechanisms of statin handling will help to minimize adverse effects and interactions, as well as to improve their lipid-lowering efficiency.     

Hepatitis C virus and GBV-C virus prevalence among patients with B-cell lymphoma in different European regions: a case-control study of the International Extranodal Lymphoma Study Group

Hepatitis C virus (HCV) infection is associated with some B‐cell non‐Hodgkin lymphoma (B cell‐NHLs). Patients with HCV infection frequently show co‐infections with GB virus C (GBV‐C, formerly known as hepatitis G virus), and some studies have suggested a higher incidence of GBV‐C infection in patients with B cell‐NHLs. The aim of this study was to prospectively evaluate the association between HCV and/or GBV‐C infection and B cell‐NHLs in different geographic areas. One hundred thirty‐seven lymphoma cases and 125 non‐lymphoma matched controls were enrolled in an international case‐control study conducted in Switzerland (Bellinzona), Spain (Barcelona) and England (Southampton) on samples collected from 2001 to 2002. In Bellinzona (41 cases and 81 controls), the overall prevalence of HCV was 3.3% (4.9% in NHLs), and the overall prevalence of GBV‐C was 24% (22% in NHLs). In Barcelona (46 cases and 44 controls), the prevalence of HCV was 10% (8.7% in NHLs) and the prevalence of GBV‐C 20% (13% in NHLs). There was no statistically significant difference in the frequency of both infections between patients with NHL and controls. In Southampton, 50 NHL cases were analysed, none of them was found to be HCV‐positive; therefore, no control group was analysed and GBV‐C analysis was not performed, too. Both in Bellinzona and in Barcelona, the seropositivity rate was significantly lower for HCV than for GBV‐C, suggesting that their transmission can be independent. The incidence of HCV was significantly higher in Barcelona than that in Bellinzona. This study confirmed the existence of marked geographic differences in the prevalence of HCV in NHL but cannot provide any significant evidence for an association between HCV and/or GBV‐C and B‐cell NHLs. Copyright © 2011 John Wiley & Sons, Ltd.