Elimination of microbes in the root canal system is crucial for achieving long-term success in endodontic treatment. Further efforts in study design and standardization are needed in order to improve ...the validity and comparability of in vitro results on endodontic disinfection procedures, in turn improving clinical outcomes. This study optimizes two models at all steps: tooth selection, pretreatment, inoculation method (by growth or centrifugation), and confocal laser scanning microscopy (CLSM)-guided imaging of LIVE/DEAD-stained specimens. Individual anatomical conditions lead to substantial differences in penetration depth. Sclerosis grading (SCG), a classification system introduced in this study, provides information about the sclerosis status of the dentine and is helpful for careful, specific, and comparable tooth selection in in vitro studies. Sonically activated EDTA for the pretreatment of roots, inoculation of
in an overflow model, 3-4 weeks of incubation, as well as polishing of dentine slices before staining, led to advances in the visualization of bacterial penetration and irrigation depths. In contrast, NaOCl pretreatment negatively affected performance reproducibility and should be avoided in any pretreatment. Nonsclerotized teeth (SCG0) can be used for microbial semilunar-shaped inoculation by centrifugation as a "quick-and-dirty" model for initial orientation. In conclusion, CLSM-guided imaging for quantifying endodontic infection/disinfection is a very powerful method after the fine-tuning of materials and methods.
•Diode lasers are used for antimicrobial photodynamic therapy (aPDT) in dentistry.•A decrease of effective laser energy has to be expected during transgingival irradiation.•Feasibility of ...transgingival laser irradiation during aPDT.•Transgingival photosensitizer activation affords higher energy settings than conventional intrapocket irradiation.
Diode lasers are commonly used for antimicrobial photodynamic therapy (aPDT). This study aimed to assess the feasibility of transgingival laser irradiation during aPDT and evaluate whether the photosensitizer can be activated.
Four diode laser settings were assessed for transgingival irradiation: 120 mW, 80 mW, 60 mW, and 40 mW. Fifteen soft-tissue pieces from a pig’s lower jaw were prepared. The specimens’ thickness was measured and transgingival laser irradiation was performed. A digital power meter measured laser power on the other side of the tissue. The power outcome after staining of the nonbuccal aspect of the tissue with photosensitizer dye was assessed similarly.
Transgingival laser irradiation (average soft-tissue thickness: 0.84 ± 0.06 mm) resulted in different power transmission depending on the power settings and photosensitizer. The lowest values were observed with the 40 mW setting and photosensitizer (median 3.3 mW, max. 5.0 mW, min. 2.3 mW, interquartile range 1.2), and the highest at 120 mW without photosensitizer (median 41.3 mW, max. 42.7 mW, min. 38.0 mW; interquartile range 1.5).
This study indicates that transgingival irradiation may be suitable for aPDT, since power transmission through the gingival tissue was observed in all specimens. However, the decrease in laser power caused by both the soft tissue and the photosensitizer has to be taken into account.
Subgingival air-polishing devices (SAPD) can reduce bacterial biofilms and thus support periodontal healing. The authors of this study evaluated the effectiveness of the glycine-based and ...trehalose-based air-polishing powders in removing pathogenic bacteria in a subgingival biofilm model. We treated 56 subgingival pockets in porcine jaws with SAPD. Subgingival air polishing was performed in three groups of 13 pockets each: I, glycine-based powder; II, trehalose-based powder; and III, water alone. Another group (IV) served as untreated controls. Prior to air polishing, inoculated titanium bars were inserted into the pockets containing periopathogenic bacteria such as
and
. Remaining bacteria were evaluated using real-time PCR. The numbers of remaining bacteria depended on the treatment procedure, with the lowest number of total bacteria in group I (median: 1.96 × 10
CFU; min: 1.46 × 10
; max: 9.30 × 10
). Both polishing powders in groups I and II (median: 1.36 × 10
CFU; min: 5.22 × 10
; max: 7.50 × 10
) showed a statistically significantly lower total bacterial load in comparison to both group IV (median: 2.02 × 10
CFU; min: 5.14 × 10
; max: 4.51 × 10
;
< 0.05) and group III (median: 4.58 × 10
CFU; min: 2.00 × 10
; max: 3.06 × 10
;
< 0.05). Both subgingival air-polishing powders investigated can reduce periopathogenic bacteria and thus support antimicrobial therapy approaches in periodontal treatment regimens.
IMPORTANCE: Surgical site infections frequently occur after open abdominal surgery. Intraoperative wound irrigation as a preventive measure is a common practice worldwide, although evidence ...supporting this practice is lacking. OBJECTIVE: To evaluate the preventive effect of intraoperative wound irrigation with polyhexanide solution. DESIGN, SETTING, AND PARTICIPANTS: The Intraoperative Wound Irrigation to Prevent Surgical Site Infection After Laparotomy (IOWISI) trial was a multicenter, 3-armed, randomized clinical trial. Patients and outcome assessors were blinded to the intervention. The clinical trial was conducted in 12 university and general hospitals in Germany from September 2017 to December 2021 with 30-day follow-up. Adult patients undergoing laparotomy were eligible for inclusion. The main exclusion criteria were clean laparoscopic procedures and the inability to provide consent. Of 11 700 screened, 689 were included and 557 completed the trial; 689 were included in the intention-to-treat and safety analysis. INTERVENTIONS: Randomization was performed online (3:3:1 allocation) to polyhexanide 0.04%, saline, or no irrigation (control) of the operative wound before closure. MAIN OUTCOME AND MEASURES: The primary end point was surgical site infection within 30 postoperative days according to the US Centers for Disease Control and Prevention definition. RESULTS: Among the 689 patients included, 402 were male and 287 were female. The median (range) age was 65.9 (18.5-94.9) years. Participants were randomized to either wound irrigation with polyhexanide (n = 292), saline (n = 295), or no irrigation (n = 102). The procedures were classified as clean contaminated in 92 cases (8%). The surgical site infection incidence was 11.8% overall (81 of 689), 10.6% in the polyhexanide arm (31 of 292), 12.5% in the saline arm (37 of 295), and 12.8% in the no irrigation arm (13 of 102). Irrigation with polyhexanide was not statistically superior to no irrigation or saline irrigation (hazard ratio HR, 1.23; 95% CI, 0.64-2.36 vs HR, 1.19; 95% CI, 0.74-1.94; P = .47). The incidence of serious adverse events did not differ among the 3 groups. CONCLUSIONS AND RELEVANCE: In this study, intraoperative wound irrigation with polyhexanide solution did not reduce surgical site infection incidence in clean-contaminated open abdominal surgical procedures compared to saline or no irrigation. More clinical trials are warranted to evaluate the potential benefit in contaminated and septic procedures, including the emergency setting. TRIAL REGISTRATION: drks.de Identifier: DRKS00012251
A growing body of literature suggests the important role of the thalamus in cognition and neurodegenerative diseases. This study aims to elucidate whether the preoperative thalamic volume is ...associated with preoperative cognitive impairment (preCI) and whether it is predictive for postoperative cognitive dysfunction at 3 months (POCD). We enrolled 301 patients aged 65 or older and without signs of dementia who were undergoing elective surgery. Magnetic resonance imaging was conducted prior to surgery. Freesurfer (version 5.3.) was used to automatically segment the thalamus volume. A neuropsychological test battery was administered before surgery and at a 3 month follow-up. It included the computerized tests Paired Associate Learning (PAL), Verbal Recognition Memory (VRM), Spatial Span Length (SSP), Simple Reaction Time (SRT), the pen-and-paper Trail-Making-Test (TMT) and the manual Grooved Pegboard Test (GPT). Using a reliable change index, preCI and POCD were defined as total Z-score > 1.96 (sum score over all tests) and/or Z-scores > 1.96 in ≥ 2 individual cognitive test parameters. For statistical analyses, multivariable logistic regression models were applied. Age, sex and intracranial volume were covariates in the models. Of 301 patients who received a presurgical neuropsychological testing and MRI, 34 (11.3%) had preCI. 89 patients (29.5%) were lost to follow-up. The remaining 212 patients received a follow-up cognitive test after 3 months, of whom 25 (8.3%) presented with POCD. Independently of age, sex and intracranial volume, neither preCI (OR per cm
increment 0.81 95% CI 0.60-1.07 p = 0.14) nor POCD (OR 1.02 per cm
increment 95% CI 0.75-1.40 p = 0.87) were statistically significantly associated with patients' preoperative thalamus volume. In this cohort we could not show an association of presurgical thalamus volume with preCI or POCD.Clinical Trial Number: NCT02265263 ( https://clinicaltrials.gov/ct2/show/results/NCT02265263 ).
BACKGROUND
Structural disconnectivity was found to precede dementia. Global white matter abnormalities might also be associated with postoperative delirium (POD).
METHODS
We recruited older patients ...(≥65 years) without dementia that were scheduled for major surgery. Diffusion kurtosis imaging metrics were obtained preoperatively, after 3 and 12 months postoperatively. We calculated fractional anisotropy (FA), mean diffusivity (MD), mean kurtosis (MK), and free water (FW). A structured and validated delirium assessment was performed twice daily.
RESULTS
Of 325 patients, 53 patients developed POD (16.3%). Preoperative global MD (standardized beta 0.27 95% confidence interval CI 0.21–0.32 p < 0.001) was higher in patients with POD. Preoperative global MK (−0.07 95% CI −0.11 to (−0.04) p < 0.001) and FA (0.07 95% CI −0.10 to (−0.04) p < 0.001) were lower. When correcting for baseline diffusion, postoperative MD was lower after 3 months (0.05 95% CI −0.08 to (−0.03) p < 0.001; n = 183) and higher after 12 months (0.28 95% CI 0.20–0.35 p < 0.001; n = 45) among patients with POD.
DISCUSSION
Preoperative structural disconnectivity was associated with POD. POD might lead to white matter depletion 3 and 12 months after surgery.
Formylmethanofuran dehydrogenases, which are found in methanogenic Archaea, are molybdenum or tungsten iron‐sulfur proteins containing a pterin cofactor. We report here on differences in substrate ...specificity, EPR properties and susceptibility towards cyanide inactivation of the enzymes from Methanosarcina barkeri, Methanobacterium thermoautotrophicum and Methanobacterium wolfei.
The molybdenum enzyme from M. barkeri (relative activity with N‐formylmethanofuran = 100%) was found to catalyze, albeit at considerably reduced apparent Vmax, the dehydrogenation of N‐furfurylformamide (11%), N‐methylformamide (0.2%), formamide (0.1%) and formate (1%). The molybdenum enzyme from M. Wolfei could only use N‐furfurylformamide (1%) and formate (3%) as pseudosubstrates. The molybdenum enzyme from M. thermoautotrophicum and the tungsten enzymes from M. thermoautotrophicum and M. wolfei were specific for N‐formylmethanofuran.
The molybdenum formylmethanofuran dehydrogenases exhibited at 77 K two rhombic EPR signals, designated FMDred and FMDox, both derived from Mo as shown by isotopic substitution with 97Mo. The FMDred signal was only displayed by the active enzyme in the reduced form and was lost upon enzyme oxidation; the FMDox signal was displayed by an inactive form and was not quenched by O2. The tungsten isoenzymes were EPR silent.
The molybdenum formylmethanofuran dehydrogenases were found to be inactivated by cyanide whereas the tungsten isoenzymes, under the same conditions, were not inactivated. Inactivation was associated with a characteristic change in the molybdenum‐derived EPR signal. Reactivation was possible in the presence of sulfide.
Einsatz von Lasern in der Endodontie Wenzler, Johannes-Simon; Krause, Felix; Braun, Andreas ...
Der Freie Zahnarzt,
2021/11, Letnik:
65, Številka:
11
Magazine Article
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