Present and Theoretical Applications of Poly-Ether-Ether-Ketone (PEEK) in Orthodontics: A Scoping Review.

Background: During the last decade, there has been an increased demand for non-metallic materials in orthodontics due to allergies, compatibility with medical imaging devices such as MRI, and aesthetic reasons. Monolithic poly-ether-ether-ketone material could address medical issues such as allergies and MRI compatibility. Moreover, nickel-titanium (NiTi) archwires covered in PEEK, either by a tube or electrophoretic deposition, could address esthetic concerns. This scoping review aims to summarize the available evidence in the literature to provide an overview of the applications and material properties of PEEK in orthodontics. Methods: This scoping review was conducted according to the Joanna Briggs Institute Manual for Evidence Synthesis for scoping reviews and the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols extension for Scoping Reviews (PRISMA-ScR). We searched for relevant publications in MEDLINE (via PubMed), Embase, Web of Science, Cochrane Library, CENTRAL, ProQuest, and SCOPUS. A gray literature search was conducted on Google Scholar. Results: Six studies were included. In three studies, the authors investigated the feasibility of developing a composite PEEK-NiTi wire, while in two other studies, the authors investigated the feasibility of monolithic PEEK wires. In the final study, the authors investigated the feasibility of PEEK as a bonded retainer. Conclusions: The included studies show promising results in developing monolithic and composite (PEEK-NiTi) materials. Further research on the robustness of PEEK composites in the oral cavity, the status of cytotoxicity and roughness values, and the (bio)-mechanical behavior of the composites is needed. A homogenously set up comparative study of clinically relevant, evenly sized, monolithic PEEK wires versus conventional orthodontic wires for their biomechanical, mechanical, and material properties would clarify the possibilities of developing monolithic PEEK wires. Missing data in the retainer study suggest more research on the mechanical properties and points of failure of PEEK-bonded retainers, and a comparative study comparing the failure and mechanical properties of PEEK-bonded retainers to flat braided metallic bonded retainers is needed.

Corrosion of orthodontic brackets: qualitative and quantitative surface analysis.

OBJECTIVES: To determine and compare surface characteristics and presence of corrosion in new and used brackets with optical light microscopy (OLM) and scanning electron microscopy (SEM), and with elemental chemical analysis with energy-dispersive X-ray spectroscopy (EDS). MATERIALS AND METHODS: OLM and SEM were used to analyze 24 new and 24 used conventional premolar brackets. EDS analysis was performed in six used brackets and four new brackets with corrosion-suspected spots. RESULTS: OLM and SEM images showed wear/abfraction signs, striations, pits/crevices, and adherent material. Used brackets showed more deterioration than new brackets. SEM images disclosed more morphological features than OLM images. EDS analysis revealed a significantly higher phosphorus (P = .001) and sodium (P < .005) weight fraction and significantly lower amounts of chromium (P < .001) in used brackets. The iron, chromium, and nickel weight fractions did not differ significantly between the clean and corrosion-suspected spots. Of the corrosion-suspected spots analyzed by combined SEM and EDS, 44.14% and 6.90% remained corrosion-suspected on used and new brackets, respectively. CONCLUSIONS: Used brackets showed more signs of corrosion than new ones. Combined assessment of SEM and EDS indicates that the bracket surface is affected during orthodontic treatment as a result of corrosion.

Biocompatible Delivery System for Metformin: Characterization, Radiolabeling and In Vitro Studies.

BACKGROUND: In recent years, the uses of nanotechnology in medicine have an increasing potential as an effective nanocarrier system. These systems are improved with the purpose of maximizing therapeutic activity and minimizing undesirable side-effects. Moreover, radiolabeled nanoparticles can be used as agents for diagnosis and therapeutic purposes in clinical applications. They have three main components: the core, the targeting biomolecule, and the radionuclide. OBJECTIVE: It is aimed to synthesize Metformin (MET) loaded Solid Lipid Nanoparticles (MET-SLN) and radiolabeled with technetium-99m tricarbonyl core. METHODS: The structure of synthesized nanoparticles was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The particle size and morphology of nanoparticles were examined by Dynamic Light Scattering (DLS), and Scanning Electron Microscope (SEM). Quality control studies of radiolabeled MET-SLN [99mTc(CO)3-MET-SLN] were performed by High-Performance Liquid Radiochromatography (HPLRC) and Thin Layer Radiochromatography (TLRC). RESULTS: The radiolabeling yield of [99mTc(CO)3-MET-SLN] was found to be 88%. In vitro studies have been performed on cancer lines(MCF7, MDA-MD-231 breast, and HEPG2 liver cancer cells) to determine the biological behavior of 99mTc(CO)3-MET-SLNs. CONCLUSION: The results showed that higher uptake values were observed on estrogen-positive MCF7 breast cancer cell line according to estrogen negative MDA-MB-231 breast cancer and HEPG2 liver cancer cell lines.

Evaluation of the alignment efficiency of nickel-titanium and copper-nickel-titanium archwires in patients undergoing orthodontic treatment over a 12-week period: A single-center, randomized controlled clinical trial.

OBJECTIVE: The aim of this trial was to compare the alignment efficiency and intermaxillary arch dimension changes of nickel-titanium (NiTi) or copper-nickel-titanium (CuNiTi) round archwires with increasing diameters applied sequentially to the mandibular arch. METHODS: The initial alignment phase of fixed orthodontic treatment with NiTi or CuNiTi round archwires was studied in a randomly allocated sample of 66 patients. The NiTi group comprised 26 women, 10 men, and the CuNiTi (27℃) group comprised 20 women, 10 men. The eligibility criteria were as follows: anterior mandibular crowding of minimum 6 mm according to Little's Irregularity Index (LII), treatment requiring no extraction of premolars, 12 to 18 years of age, permanent dentition, skeletal and dental Class I malocclusion. The main outcome measure was the alignment of the mandibular anterior dentition; the secondary outcome measure was the change in mandibular dental arch dimensions during 12 weeks. Simple randomization (allocation ratio 1:1) was used in this single-blind study. LII and mandibular arch dimensions were measured on three-dimensional digital dental models at 2-week intervals. RESULTS: No statistically significant difference was observed between NiTi and CuNiTi according to LII (p > 0.05). Intercanine and intermolar arch perimeters increased in the CuNiTi group (p < 0.001). Inter-first premolar width showed a statistically significant interaction in week × diameter × application (p < 0.05). CONCLUSIONS: The effects of NiTi and CuNiTi round archwires were similar in terms of their alignment efficiency. However, the intercanine and intermolar arch perimeters, and the inter-first premolar width changes differed between groups.

Comprehension of Idioms in Turkish Aphasic Participants.

Brain damaged participants offer an opportunity to evaluate the cognitive and linguistic processes and make assumptions about how the brain works. Cognitive linguists have been investigating the underlying mechanisms of idiom comprehension to unravel the ongoing debate on hemispheric specialization in figurative language comprehension. The aim of this study is to evaluate and compare the comprehension of idiomatic expressions in left brain damaged (LBD) aphasic, right brain damaged (RBD) and healthy control participants. Idiom comprehension in eleven LBD aphasic participants, ten RBD participants and eleven healthy control participants were assessed with three tasks: String to Picture Matching Task, Literal Sentence Comprehension Task and Oral Idiom Definition Task. The results of the tasks showed that in overall idiom comprehension category, the left brain-damaged aphasic participants interpret idioms more literally compared to right brain-damaged participants. What is more, there is a significant difference in opaque idiom comprehension implying that left brain-damaged aphasic participants perform worse compared to right brain-damaged participants. On the other hand, there is no statistically significant difference in scores of transparent idiom comprehension between the left brain-damaged aphasic and right brain-damaged participants. This result also contribute to the idea that while figurative processing system is damaged in LBD aphasics, the literal comprehension mechanism is spared to some extent. The results of this study support the view that idiom comprehension sites are mainly left lateralized. Furthermore, the results of this study are in consistence with the Giora's Graded Salience Hypothesis.

Comparison of clinical and perinatal outcomes in early- and late-onset preeclampsia.

PURPOSE: To compare the clinical and laboratory findings and maternal-perinatal outcomes between women with early-onset preeclampsia (EO-PE) and late-onset preeclampsia (LO-PE). METHODS: One hundred and fifty-four women with preeclampsia (PE) who delivered in our clinic were included in the study. Perinatal and obstetric outcomes were evaluated. RESULTS: The incidence of abnormal uterine artery (UtA) velocity waveform was significantly higher in the EO-PE group (71.4 vs 30.1 %) (p < 0.001). The incidences of small-for-gestational age, oligohydramnios, Apgar score <7 at 5 min, stillbirth and early neonatal death rates were significantly higher in women with EO-PE compared to LO-PE (p < 0.01). Maternal complications were only recorded in women with severe PE. CONCLUSION: EO-PE, especially with abnormal UtA Doppler findings defines a placentation abnormality with higher perinatal adverse outcomes.

Double Meckel's diverticulum presenting as acute appendicitis: a case report and literature review.

BACKGROUND: Meckel's diverticulum is the most common developmental anomaly of the gastrointestinal tract, affecting 1-3% of the general population. This anomaly is caused by incomplete obliteration of the omphalomesenteric duct during the 7th week of gestation and is located in the last meter of the ileum in 90% of patients. Meckel's diverticulum is often an incidental finding during a laparotomy for other causes, such as acute appendicitis, and occasional complications are bleeding, obstruction, diverticulitis, and perforation. OBJECTIVE: Primary aim of this study was to present and share an extremely rare case of double Meckel's diverticulum. METHODS: A 20-year-old woman who was admitted due to symptoms of right lower quadrant pain, nausea, and vomiting. A laparotomy with a McBurney's incision was performed because of a presumed diagnosis of acute appendicitis. The surgical exploration revealed a double Meckel's diverticulum localized 50 cm proximal to the ileocecal valve, but no acute appendicitis. The operation was finished after a diverticulectomy and appendectomy. No complications occurred during the postoperative follow-up. CONCLUSIONS: We conducted a literature review of studies published in the English language on double Meckel's diverticulum, accessed via PubMed, Medline, and the Google Scholar databases. We found only five case reports of such a Meckel's diverticulum variant.

First-trimester maternal serum metastin, placental growth factor and chitotriosidase levels in pre-eclampsia.

OBJECTIVE: To investigate whether the serum levels of metastin and PIGF and chitotriosidase activity early in pregnancy differ in women who develop pre-eclampsia from those who remain normotensive. STUDY DESIGN: A retrospective case-control study of prospectively collected data. Thirty healthy pregnant women and 31 women with pre-eclampsia were included in the study. Serum samples were collected at 11-14 weeks and stored at -70°C. Levels of metastin, PIGF and chitotriosidase activity were measured in serum from pregnant women with subsequent development of pre-eclampsia and matched controls. RESULTS: Mean maternal serum metastin (1554 ± 385 pmol/L vs 1995 ± 375 pmol/L, p<0.001) and PIGF (111.9 ± 7.0 pg/mL vs 124.9 ± 3.5 pg/mL, p<0.001) levels were significantly lower and chitotriosidase activity was significantly higher (681.6 ± 248.3 nmol/mL/h vs 527.7 ± 223.1 nmol/mL/h, p<0.01) in women who subsequently developed pre-eclampsia than in those who remained normotensive. The areas under the curve equal to 0.797, 0.831 and 0.681 (p<0.001, p<0.001 and p<0.01) for metastin, PIGF, and chitotriosidase respectively were determined for the prediction of pre-eclampsia. CONCLUSIONS: Metastin and PIGF levels and chitotriosidase activity are altered in the first trimester serum of women destined to become pre-eclamptic, reflecting placental dysfunction. Metastin, like PIGF, may have a potential to be used as a first-trimester biomarker of pre-eclampsia.

Case report: gastric carcinoma diagnosed at the second trimester of pregnancy.

We report a rare case of gastric cancer in pregnancy. A 26-year-old woman presented at the 20th week of pregnancy complaining of nausea and vomiting. Although the patient considered the condition to be related with pregnancy and underestimated its importance, her complaints persisted over the following weeks and she was hospitalized for investigation. The diagnostic workup revealed a metastatic gastric cancer. Gastric cancer is very rare in pregnancy, and therefore it may be left out of differential diagnosis by physicians. Diagnosis may be further delayed because of overlapping symptoms occurring during normal pregnancy (nausea, vomiting, and fatigue). All these factors may contribute to a very high mortality of this malignancy during pregnancy.