Computational Analysis of Polymeric Biodegradable and Customizable Airway Stent Designs.

The placement of endotracheal prostheses is a procedure used to treat tracheal lesions when no other surgical options are available. Unfortunately, this technique remains controversial. Both silicon and metallic stents are used with unpredictable success rates, as they have advantages but also disadvantages. Typical side effects include restenosis due to epithelial hyperplasia, obstruction and granuloma formation. Repeat interventions are often required. Biodegradable stents are promising in the field of cardiovascular biomechanics but are not yet approved for use in the respiratory system. The aim of the present study is to summarize important information and to evaluate the role of different geometrical features for the fabrication of a new tracheo-bronchial prosthesis prototype, which should be biodegradable, adaptable to the patient's lesion and producible by 3D printing. A parametric design and subsequent computational analysis using the finite element method is carried out. Two different stent designs are parameterized and analyzed. The biodegradable material chosen for simulations is polylactic acid. Experimental tests are conducted for assessing its mechanical properties. The role of the key design parameters on the radial force of the biodegradable prosthesis is investigated. The computational results allow us to elucidate the role of the pitch angle, the wire thickness and the number of cells or units, among other parameters, on the radial force. This work may be useful for the design of ad hoc airway stents according to the patient and type of lesion.

Primary stability and PES/WES evaluation for immediate implants in the aesthetic zone: a pilot clinical double-blind randomized study.

The use of immediate implants in the aesthetic area is a technique widely used in modern implantology. The characteristics of the patient, the implant, and the surgical procedure used may influence the final results. The aim was to assess whether the implant design affects primary (P.S.) and secondary stability (S.S.), bone level (B.L.), and PES/WES evaluation. Twenty implants with two different designs (n = 10) were immediately placed and randomly located in the upper anterior maxilla with no grafting material. Implant-Stability-Quotient (ISQ), B.L., and Pink-Esthetic-Score/White-Esthetic-Score (PES/WES) were evaluated. Shapiro-Wilk normality test was performed to determine the sample normality, as the data did not follow a normal distribution, the Wilcoxon-Mann-Whitney test was applied (p < 0.05). ISQ was determined at placement (PS): control 59.1 (C.I.54.8-63.3); experimental 62.2(C.I.60.1-64.2) and three months after placement (SS): control 62.2.1 (C.I.53.3-71.0); experimental 67.2(C.I.65.8-68.5). The BL was measured at three months after placement: control 0.38 mm (C.I.- 0.06 to + 0.83); experimental 0.76 mm (C.I.0.33-1.19) and at 12 months post-loading: control 0.07 mm (C.I.- 0.50-0.65); experimental 0.90 mm (C.I.0.38-1.42). PES/WES values were evaluated for the control group: 15 (C.I.12.68-17.32), and for the experimental group 15.20 (C.I.11.99-18.41). No significant differences were shown between both implant designs. A good grade of osseointegration and primary/secondary stability was achieved, as well as proper maintenance of crestal bone and adequate PES/WES scores. The criteria for selection for the ideal patient for immediate implant placement is essential.ClinicalTrials Protocol ID: NCT04343833.

Tratamiento del aspergiloma pulmonar en paciente de alto riesgo quirúrgico: cavernostomía / Cavernostomy in the Treatment of Pulmonary Aspergilloma in a High Surgical Risk Patient

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Abordaje toracoscópico de perforación iatrogénica de vena cava superior por catéter de diálisis / Thoracoscopic approach of iatrogenic superior vena cava perforation after dialysis catheter placement

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Control of Peri-Implant Mucous Inflammation by Using Chlorhexidine or Ultraviolet C Radiation for Cleaning Healing Abutments. Double-Blind Randomized Clinical Trial.

Two-phase implants must be exposed to the external environment after the period of osteointegration has elapsed. For this purpose, a healing abutment is placed passing through the mucosa while forming the emergence profile. The continuous connection and disconnection can lead to an alteration in the tissue maturation, both because of the contact of bacterial plaque and because of the mechanical trauma that involves its manipulation, manifesting with different degrees of erythema or bleeding. To assess whether this epithelium disruption can be counteracted, a blinded study design was developed on 150 unitary implant patients divided into three groups (n = 50), applying chlorhexidine (group 1), ultraviolet C (UV-C) at a wavelength of 254 nm (group 2)and no treatment as a control group (group 3), during each of the disconnections and connections during the prosthodontic treatment (1 time per week for four weeks). All groups showed a better epithelium aspect at the end of the evaluation. Although there were no statistically significant differences in the degree of inflammation, the UV-C treated group had the lowest plaque accumulation, and the highest was for the chlorhexidine-treated group.

Effects of Ultraviolet Photoactivation on Osseointegration of Commercial Pure Titanium Dental Implant After 8 Weeks in a Rabbit Model.

This study investigated whether a 6-Watt ultraviolet C-lamp was capable of producing photofunctionalization on commercial implants during a medium observation term of 8 weeks. A total of 20 implants were inserted in 5 New Zealand rabbits, with each animal receiving 2 implants per tibia (one photofunctionalized and one untreated), according to a previously established randomization sequence. All implants were inserted by a single surgeon following the manufacturer's instructions. Histological analysis was performed by an evaluator who was blinded to the treatment condition. After 8 weeks of healing, the 2 groups showed no statistically significant differences in terms of bone-to-implant contact. Compared to control implants, the photofunctionalized implants showed improved wettability and more homogenous results. Within the limits of the present study, the use of this 6-W ultraviolet C-lamp, for an irradiation time of 15 minutes at a distance of 15 cm, did not improve the percentages of bone-to-implant contact in rabbits at an osseointegration time of 8 weeks.

Effects of the Preoperative Administration of Dexketoprofen Trometamol on Pain and Swelling After Implant Surgery: A Randomized, Double-Blind Controlled Trial.

The fear of postoperative pain is often mentioned by patients as one of the factors that is most frequently associated with dental implants. To reduce this factor, a single oral dose of 25 mg dexketoprofen trometamol (DKT) or placebo was administered 15 minutes before implant surgery. One hundred patients who required single-implant treatments were randomly assigned to 1 of 2 blinded groups. The patients in the test group were given 25 mg DKT (DKT group), and those in the control group were given 500 mg vitamin C as a placebo (PLACEBO group). A subjective visual analogue scale of 100 mm in length was used to evaluate pain. Inflammation and complications were assessed using a 5-point Likert scale. An analysis of variance, t-tests, and a Mann-Whitney U test were performed. Among the 100 patients, 83 completed the study (there were 8 dropouts in the PLACEBO group and 9 in the DKT group). The patients who received DKT reported a lower pain intensity during the immediate postoperative period. The inflammatory response was weaker in the DKT group than the control group at 48 hours, but bleeding was greater. There were no other complications in either of the groups. In conclusion, the preemptive use of 25 mg soluble DKT administered orally 15 minutes before implant surgery can reduce the severity of immediate postoperative pain.