Current options of making implant supported prosthetic restorations to mitigate the impact of occlusal forces

Rezumat. Lipsa ţesutului parodontal pentru un implant dentar poate duce la o concentraţie mare de stres la nivelul osului, atunci când implanturile sunt încărcate protetic. Prezentul articol discută posibilităţile curente ale realizării protezelor cu suport pe implant, pentru a diminua impactul forţelor ocluzale. Stratul de ciment poate servi ca un absorbant pentru tensiune, dar rolul acestuia este redus și există riscul de reţinere al excesului de ciment în ţesutul peri-implantar. Utilizarea materialelor rășinice pentru faţetarea restaurărilor protetice cu suport pe implant a fost sugerată de-a lungul multor ani, dar rolul lor este important în cazul unei proteze ale arcadei totale fixate pe implante, cu canelură distală și mai puţin în restaurările pe un singur implant. În zilele noastre, materiale noi, cum ar fi compozitele armate cu fibră și polimerii de înaltă performanţă ca PEEK pot fi utilizate pentru scheletul restaurărilor cu suport pe implant, dar și pentru realizarea stâlpului restaurărilor protetice cu suport pe implant.Summary. The lack of a periodontium for a dental implant may lead to high stress concentration at the bone level when the implants are prosthetically loaded. The present paper discusses the current possibilities of implant supported prosthesis making in order to mitigate the impact of occlusal forces. The cement layer may serve as an absorber for the strain, but its role is reduced and poses the risk of excess cement retained in the peri-implant tissue. The use of resin materials for the implant supported prosthetic restorations veneering it has been suggested for many years, but their role it is important in the case of full-arch fixed implant-supported prosthesis with cantilever distal extensions and less in single implant restorations. Nowadays, new materials like fiber-reinforced composites and high-performance polymers as PEEK may be used for the framework of the implant supported prosthetic restorations, but also for the implant or the prosthetic abutment realization

A rare complication of acute appendicitis – case presentation

Introduction. Considered by many authors a vestigial structure, the appendix is a small dimensions organ with mostly unknown functions. Acute appendicitis is the most common condition of the ileocecal appendix, having multifaceted clinical manifestations, often masquerading as various unrelated syndromes, but causing increased morbidity, especially when diagnosed late. Although the disease could manifest at any age, there is a progressive increase of its incidence from birth, with a maximum between 10 to 40 years. Case presentation. We report the case of an 84 years-old female patient, who presented with significant abdominal pain in the lower quadrants, mainly in the right iliac fossa and in whom the CT examination was suggestive of a utero-appendicular fistula, a very rare complication in daily practice and even more seldomly encountered in the elderly. Conclusions. Acute appendicitis remains a condition for which surgery is still the optimum treatment, especially in the case of an elderly patient having a radiologically suspected fistula with the uterus that could easily lead to septic gynecological complications and possibly progression to multiple organ failure

Essentials of surgical anatomy and technique in TAPP repair of inguinal hernia

Laparoscopic hernia repair has opened a new era in hernia surgery shifting paradigms from anterior to posterior approaches. This has exposed surgeons to new anatomical perspectives, technical challenges and clinical implications all of which preventing the technique from becoming ubiquitous despite numerous advantages, limited contraindications and low recurrence rates. In order to address the difficult learning curve of the laparoscopic transabdominal preperitoneal hernia repair this paper presents the experience and points of view from a tertiary surgical department on the systematization of anatomical concepts pertinent to the TAPP repair technique, a decalogue of suggestions related to the surgical technique and a short reminder of the most common complications and how to avoid them. Revising the anatomy essentials and proposing a decalogue of the surgical technique and a memento on the most common complications will provide young surgeons with a scaffold of basic knowledge on TAPP hernia repair

Toxic Blood Hydrogen Cyanide Concentration as a Vital Sign of a Deceased Room Fire Victim—Case Report

Carbon monoxide (CO) and hydrogen cyanide (HCN) are two common toxic products of combustion. HCN concentrations of fire victims are not routinely determined in most legal medicine services in Romania. We present the case of a room fire victim in which we evaluated the concentrations of HCN and carboxyhemoglobin (COHb), their contribution to the mechanism of death, and the possibility that HCN concentration can be interpreted as vital sign. COHb was determined by spectrophotometry. HCN was spectrophotometrically determined with ninhydrin in postmortem blood samples after its removal with 20% phosphoric acid and uptake into a solution of potassium carbonate. The presence of ethyl alcohol was determined by gas chromatography. The COHb concentration was 6.15%, while the blood HCN concentration was 1.043 µg × mL−1 and the total HCN was 1.904 µg × ml−1. A blood alcohol content of 4.36 g‰ and a urine alcohol content of 5.88 g‰ were also found. Although the fire produced a considerable amount of soot, and there were signs of inhalation of soot particles, the COHb level cannot be interpreted as a vital sign. Toxic concentrations of HCN and total HCN can be interpreted as a vital sign and indicates a contributive effect of HCN in the mechanism of death

Effect of the Antimicrobial Agents Peppermint Essential Oil and Silver Nanoparticles on Bone Cement Properties

The main problems directly linked with the use of PMMA bone cements in orthopedic surgery are the improper mechanical bond between cement and bone and the absence of antimicrobial properties. Recently, more research has been devoted to new bone cement with antimicrobial properties using mainly antibiotics or other innovative materials with antimicrobial properties. In this paper, we developed modified PMMA bone cement with antimicrobial properties proposing some experimental antimicrobial agents consisting of silver nanoparticles incorporated in ceramic glass and hydroxyapatite impregnated with peppermint oil. The impact of the addition of antimicrobial agents on the structure, mechanical properties, and biocompatibility of new PMMA bone cements was quantified. It has been shown that the addition of antimicrobial agents improves the flexural strength of the traditional PMMA bone cement, while the yield strength values show a decrease, most likely because this agent acts as a discontinuity inside the material rather than as a reinforcing agent. In the case of all samples, the addition of antimicrobial agents had no significant influence on the thermal stability. The new PMMA bone cement showed good biocompatibility and the possibility of osteoblast proliferation (MTT test) along with a low level of cytotoxicity (LDH test)

Laser-evoked synaptic transmission in cultured hippocampal neurons channelrhodopsin-2 delivered by adeno-associated virus

We present a method for studying synaptic transmission in mass cultures of dissociated hippocampal neurons based on patch clamp recording combined with laser stimulation of neurons expressing channelrhodopsin-2 (ChR2). Our goal was to use the high spatial resolution of laser illumination to come as close as possible to the ideal of identifying monosynaptically coupled pairs of neurons, which is conventionally done using microisland rather than mass cultures. Using recombinant adeno-associated virus (rAAV) to deliver the ChR2 gene, we focused on the time period between 14 and 20 days in vitro, during which expression levels are high, and spontaneous bursting activity has not yet started. Stimulation by wide-field illumination is sufficient to make the majority of ChR2-expressing neurons spike. Stimulation with a laser spot at least 10 μm in diameter also produces action potentials, but in a reduced fraction of neurons. We studied synaptic transmission by voltage-clamping a neuron with low expression of ChR2 and scanning a 40 μm laser spot at surrounding locations. Responses were observed to stimulation at a subset of locations in the culture, indicating spatial localization of stimulation. Pharmacological means were used to identify responses that were synaptic. Many responses were of smaller amplitude than those typically found in microisland cultures. We were unable to find an entirely reliable criterion for distinguishing between monosynaptic and polysynaptic responses. However, we propose that postsynaptic currents with small amplitudes, simple shapes, and latencies not much greater than 8 ms are reasonable candidates for monosynaptic interactions.Howard Hughes Medical Institut