Schneiden oder nicht schneiden: (medizin-)rechtliche Verantwortung des Arztes bei einem Patienten,bei dem eine Amputation unterhalb des Knies ohne seine Zustimmung geplant ist

Die Anaesthesiologie -     

Impaired semen parameters in patients with confirmed SARS-CoV-2 infection: A prospective cohort study

In this prospective study, we investigated the impact of SARS-CoV-2 infection on semen parameters in a cohort of men who had recently recovered from COVID-19. A total of 24 men who had recently recovered from mild COVID-19 were included in the study. Their semen parameters were normal before COVID-19 according to the World Health Organization 2010 reference values. Semen samples were collected from these participants in the recovery phases of COVID-19. To determine the effect of SARS-CoV-2 infection on semen parameters, the patients' pre-COVID-19 and post-COVID-19 semen analyses were compared. The mean age of the participants was 34.7 ± 6.4 years. The median interval between the positive nasopharyngeal swab test and obtaining semen samples was 111.5 (158) days. There was no significant difference in semen parameters before and after COVID-19 in terms of semen volume (p = .56), sperm concentration (p = .06), and progressive motility (p = .14). Total motility (p = .01) and total motile sperm count (p = .02) decreased significantly after SARS-CoV-2 infection compared to the pre-infection values. This study demonstrated that sperm motility and total motile sperm count were the semen parameters which showed a significant reduction in cases with a history of mild COVID-19.     

Effects of sunitinib and bevacizumab on VEGF and miRNA levels on corneal neovascularization

Aim: To evaluate the effects of sunitinib (0.5?mg/ml) and bevacizumab (5?mg/ml) on VEGF-A, VEGFR-2 and microRNA (miRNA) levels on corneal neovascularization (CNV).

Methods: In this study, CNV was induced by silver nitrate application to the cornea, and 40 Albino male rats were equally divided into four subgroups:

Group 1 (sunitinib): After silver nitrate application to the cornea, 0.5?mg/ml sunitinib eyedrop was administered twice daily for two weeks (n?=?10).

Group 2 (bevacizumab): After silver nitrate application to the cornea, 5?mg/ml bevacizumab eyedrop was administered twice daily for two weeks (n?=?10).

Group 3 (control): After silver nitrate application to the cornea, normal saline eyedrop was administered twice daily for two weeks (n?=?10).

Group 4 (vehicle): After silver nitrate application to the cornea, 1% DMSO eyedrop was administered twice daily for two weeks (n?=?10).

After two weeks from the silver nitrate application, corneas were evaluated by hand-held biomicroscope for their vascularization status. Then, corneas were excised and the expression levels of VEGFR-2, VEGF-A and the common miRNA markers for neovascularization (miR-15?b, miR-16, miR-23a, miR-126, miR-188, miR-210, miR-221, miR-222, miR-410 and miR-423) were evaluated by real-time PCR.

Results: It was seen that the CNV was decreased in sunitinib- and bevacizumab-administered groups compared to the control and DMSO groups. Also, in comparison with the control group; VEGF-A expression was downregulated by nearly 0.75 times in sunitinib group and nearly 0.52 times in bevacizumab group. VEGFR-2 expression was downregulated by 0.89 times in sunitinib group and 0.68 times in bevacizumab group, compared to the control group. miR-15?b, miR-16 and miR-126 levels were statistically lower in sunitinib and bevacizumab groups, but miR-188 and miR-410 levels were two-fold higher compared to the control group. The miR-210 level was found higher only in sunitinib group compared to the control group. There were no statistically significant changes in miR-23a, miR-221, miR-222 and miR-423 levels among the groups.

Conclusion: Topical application of bevacizumab (5?mg/ml) and sunitinib (0.5?mg/ml) decreases the levels of VEGFR-2 and VEGF-A in CNV. Further studies are needed for detailed analysis of genes which are targeted by up- or downregulated miRNAs in this study.     

A complication of nasotracheal intubation after mandibular subcondylar fracture

Among the potential risks of nasotracheal intubation are nasal bleeding, sinusitis, bacteremia, accidental turbinectomy, and some other structural damages. Retropharyngeal dissection is reported as a very rare complication of nasotracheal intubation, mostly encountered in elective surgery patients. A case with traumatic subcondylar fracture of the mandible is presented here, which is suspected to be the cause of the nasopharyngeal dissection that was observed during attempted nasotracheal intubation.     

Analysis of the potential association of implant stability, laboratory, and image-based measures used to assess osteotomy sites: early versus delayed loading

BACKGROUND: During the assessments made at presurgical, surgical, and follow-up phases, the clinician may benefit from a wide array of clinical and/or image-based measures. Because analysis of the potential associations among the various measures could improve the evaluation process for dental implants, this study attempted to determine the potential correlations among peri-implant sulcus fluid (PISF) volume, implant stability, nitric oxide content of PISF, and marginal bone loss. METHODS: Seventeen completely edentulous patients seeking prosthetic rehabilitation were included. Two ball attachment mandibular overdentures were given to all patients, and early- (N = 18) and delayed-loaded (N = 16) dental implants were compared during 24-weeks of follow-up. Resonance frequency analysis (RFA), marginal bone level, and PISF samples were taken for all dental implants. RESULTS: A consistent and negative correlation was observed between RFA measurements and marginal bone level, whereas some correlations also existed between RFA and PISF volume. The pattern of loading seemed to affect the relationship between RFA measurements and marginal bone level and, to a limited extent, the association between PISF volume and nitrite levels. CONCLUSIONS: Where the potential associations among various implant-related measures are concerned, the factors that may affect such associations (e.g., healing and loading) need to be considered. Data arising from the analysis of the associations between the wide arrays of available implant-related measures may improve dental practitioners' assessment concerning endosseous dental implants.     

Effects of surface-conditioning methods on shear bond strength of brackets bonded to different all-ceramic materials

The aims of this study were to investigate the effects of two surface-conditioning methods on the shear bond strength (SBS) of metal brackets bonded to three different all-ceramic materials, and to evaluate the mode of failure after debonding. Twenty feldspathic, 20 fluoro-apatite, and 20 leucite-reinforced ceramic specimens were examined following two surface-conditioning methods: air-particle abrasion (APA) with 25 μm Al(2)O(3) and silica coating with 30 μm Al(2)O(3) particles modified by silica. After silane application, metal brackets were bonded with light cure composite and then stored in distilled water for 1 week and thermocycled (×1000 at 5-55°C for 30 seconds). The SBS of the brackets was measured on a universal testing machine. The ceramic surfaces were examined with a stereomicroscope to determine the amount of composite resin remaining using the adhesive remnant index. Two-way analysis of variance, Tukey's multiple comparison test, and Weibull analysis were used for evaluation of SBS. The lowest SBS was with APA for the fluoro-apatite ceramic (11.82 MPa), which was not significantly different from APA for the feldspathic ceramic (13.58 MPa). The SBS for the fluoro-apatite ceramic was significantly lower than that of leucite-reinforced ceramic with APA (14.82 MPa). The highest SBS value was obtained with silica coating of the leucite-reinforced ceramic (24.17 MPa), but this was not significantly different from the SBS for feldspathic and fluoro-apatite ceramic (23.51 and 22.18 MPa, respectively). The SBS values with silica coating showed significant differences from those of APA. For all samples, the adhesive failures were between the ceramic and composite resin. No ceramic fractures or cracks were observed. Chairside tribochemical silica coating significantly increased the mean bond strength values.     

Effects of various finishing procedures on the staining of provisional restorative materials

STATEMENT OF PROBLEM: The color stability of tooth-colored restorative materials for provisional restorations is of primary importance when provisional prostheses are worn long term. However, the effect of different polishing methods on the color difference of provisional restorative (PR) materials has not been completely clarified. PURPOSE: The purpose of this study was to investigate the effect of different polishing methods on color stability of 2- and 3-component autopolymerized bis-acrylic composites, a light polymerized composite, and a methyl methacrylate-based PR material upon exposure to a staining agent. Material and methods Sixty cylindrical specimens (15 x 2 mm) were prepared for each of bis-acryl composites (Protemp II and Luxatemp), a light-polymerized composite (Revotek LC), and a methyl methacrylate-based (TemDent) PR material by using a brass mold. The specimens were divided into 6 groups (n=10), and different polishing procedures were used, including pumice (P), diamond polishing paste (Dpp), polishing discs (Pd), and combinations of these. Unpolished specimens served as the control. The specimens were stored for 48 hours at 37 degrees C in a coffee solution. The color of all specimens was measured with a colorimeter (Minolta CR-300) before and after exposure, and color changes (DeltaE) were calculated. The data were analyzed with a 2-way analysis of variance, and mean values were compared by the Tukey Honestly Significant Difference test (alpha=.05). RESULTS: The provisional materials, surface polishing procedures, and interaction were significant (P <.05). In the light-polymerized composite group, the lowest color difference (DeltaE) was observed in Group P-Dpp (4.9) and Group P (5.3), which were not significantly different from each other. In the autopolymerized bis-acryl composites and the methyl methacrylate-based provisional materials, the lowest color difference (DeltaE) was observed in Group P-Dpp. The largest color difference for the light-polymerized and autopolymerized composites was observed in Group Pd-Dpp and Group Pd, which were not significantly different from each other. In the methyl methacrylate-based material group, the largest color difference was observed in Group Pd. When comparing the 4 different PR materials, the methyl methacrylate-based material group demonstrated statistically significantly less color change than the other provisional material tested. CONCLUSION: The methyl methacrylate-based PR material (TemDent) was found to be more color stable than the autopolymerized (Protemp II and Luxatemp) and light-polymerized (Revotek LC) composites tested. The use of diamond polishing paste after polishing with pumice significantly decreased the staining of methyl metacrylate and bis-acryl composites tested. The highest color-change values were obtained in the groups polished with polishing discs, which were found to be significantly different compared to values obtained with other polishing techniques.     

The effect of food simulants on porcelain-composite bonding.

PURPOSE: The purpose of this study was to evaluate the in vitro effects of food simulants on the bond strength of brackets to porcelain surfaces. MATERIALS AND METHODS: One hundred and eighty porcelain-fused to metal specimens were fabricated. Samples were divided into 3 groups including 60 specimens each. Different surface treatment methods were applied to each group and these were: sandblasting (SB), etching with orthophosphoric acid (OPA) and etching with hydrofluoric acid (HFA). After the surface treatments, the brackets were bonded to the center of each sample with a light-curing orthodontic composite adhesive. Then each group was divided into five test subgroups and one control subgroup each consisting of 10 specimens. The test groups were conditioned for 90 days at 37 degrees C as follows: water, 0.02N citric acid, heptane, 8% ethanol aqueous solution and 50% ethanol aqueous solution. The control specimens were stored at room temperature in air. Shear force was applied to the porcelain-bracket interface by using a universal testing machine with a crosshead speed of 1 mm/min until debonding occurred. The shear bond strength was calculated by dividing the maximum load by the cross-sectional area of the bracket to give the results in megapascals (MPa). The statistical evaluations were made by using analysis of variance. Whenever a significance was detected, Bonferroni tests were performed for post hoc analyses. RESULTS: Fifty percent ethanol conditioned specimens for all surface treatment groups showed lower shear bond strength values. HFA group showed significantly higher shear bond strength values when compared with other groups (P < 0.05). For all porcelain surface treatment groups, control groups showed statistically significant higher shear bond strength values (P < 0.05). CONCLUSION: The results of this in vitro study show that food simulants significantly decrease the bond strength between bracket and porcelain surface.