71 research outputs found
Evaluation of Dental Surface after De-Bonding Orthodontic Bracket Bonded with a Novel Fluorescent Composite: In Vitro Comparative Study
The use of a new fluorescent composite can reduce some of the problems related to procedures of de-bonding orthodontic bracket (enamel damage, dentine lesions, and composite residuals). The aim of the presented study was to compare the effect of fluorescent and conventional non-fluorescent composite on dental surface and composite remnants by in vitro de-bonding tests. De-bonding of florescent composite (DFC) and the de-bonding of standard composite (DSC) were performed by operators on an in vitro sample of 48 teeth under UV light (360–370 nm min 20 mW/cm2). Modified ARI (Adhesive Remnant Index), scored under 5.0×/235 magnification, was used for evaluation of dental surface after the procedure, and the duration required for de-bonding was measured. Significant differences in ARI between the two groups were observed (Pearson two-tailed p = 0.006 1.4 ± 0.1 95% C.I.), and the average duration of de-bonding was 38 s (DFC) and 77 s (DSC) per tooth, respectively (Mann–Whitney test p = 0.015; 57.7 ± 19.9 95% C.I.). The use of fluorescent composite could significantly improve the quality of de-bonding by reducing the quantity of composite residuals and visible enamel damage, while reducing time needed for successful procedure performance
Evolution and architecture of a West Mediterranean upper Pleistocene to Holocene coastal apron-fan system
The Quaternary deposits of tectonically stable areas are a powerful tool to investigate high-frequency climate variations (<10 ka) and to distinguish allogenic and autogenic factors controlling deposition. Therefore, an Upper Pleistocene—Holocene coastal apron-fan system in north—western Sardinia (Porto Palmas, Italy) was studied to investigate the relations between climate changes, sea-level fluctuations and sediment source-supply that controlled its development. The sedimentary sequence records the strong influence of local (wet/dry) and worldwide (sea-level) environmental variations in the sedimentation and preservation of the deposits. A multi-disciplinary approach allowed subdivision of the succession into four major, unconformity-bounded stratigraphic units: U1 U2, U3 and U4. Unit U1, tentatively dated to the warm and humid Marine Isotopic Stage (MIS) 5, consists of sandy, gravelly coastal/beach deposits developed during high sea-level in low-lying areas. Unit U2 consists of debris-flow dominated fan-deposits (ca 74 ka; MIS 4), preserved as partial fills of small valleys and coves. Unit U2 is mainly composed of reddish silty conglomerate to pebbly siltstones sourced from the Palaeozoic metamorphic inland hills (bedrock), superficially disintegrated during the preceding warm, vegetation-rich MIS 5. The cold and semi-arid climate strongly reduced vegetation cover along the valley flanks. Therefore, sediment gravity-flow processes, possibly activated by rainstorms, led to deposition of debris-flow dominated fans. Unit U3 consists of water-flow dominated alluvial-fan deposits (ca 47 to 23 ka; MIS 3), developed on a slightly inclined coastal plain. Unit U3 is composed of sandstone and sandy conglomerate fed from two main sediment sources: metamorphic inland bedrock and Quaternary bioclastic-rich shelf-derived sands. During this cold phase, sea-level dropped sufficiently to expose bioclastic sands accumulated on the shelf. Frequent climate fluctuations favoured inland aeolian transport of sand during dry phases, followed by reworking of the aeolian bodies by flash floods during wet phases. Bedrock-derived fragments mixed with water-reworked, wind-blown sands led to the development of water-flow dominated fans. The Dansgaard—Oeschger events possibly associated with sand landward deflation and main fan formations are Dansgaard—Oeschger 13 (ca 47 ka), Dansgaard—Oeschger 8 (ca 39 ka) and Dansgaard—Oeschger 2 (ca 23 ka). No record of sedimentation during MIS 2 was observed. Finally, bioclastic-rich aeolianites (Unit U4, ca 10 to 5 ka; MIS 1), preserved on a coastal slope, were developed during the Holocene transgression (ca 10 to 5 ka; MIS 1). The studied sequence shows strong similarities with those of other Mediterranean sites; it is, however, one of the few where the main MIS 4 and MIS 3 climatic fluctuations are registered in the sedimentary record
Is Orthodontic Treatment with Microperforations Worth It? A Scoping Review
Malformations of teeth and dental arches can produce functional modifications intermingled
with esthetic alterations. Children’s rehabilitation may be long, requiring multiple interventions.
One of the main challenges of contemporary orthodontics is to reduce treatment time by accelerating
orthodontic tooth movements. Among the currently used methods, micro-osteoperforations
(MOPs) are flapless, minimally invasive perforations that induce a local trauma to the bone,
increase healing capacity, and accelerate dental movements. The use of MOPs in orthodontics is
spreading but there are no definite and recognized protocols for their application. This scoping review
collected the available evidence in the effect of MOPs during orthodontic therapy as compared
to current treatments, to summarize the evidence. The guidelines proposed by PRISMA-ScR were
followed: original clinical studies carried out from 2010 to 2021 were retrieved by medical databases
combining the terms “micro-osteoperforations” and “accelerated orthodontic tooth movement”.
From a total of 965 articles, nine were finally selected. The studies' aims, designs, methods, measurements,
outcomes, and main findings were very heterogenous, with a duration ranging from 4
weeks to 7 months. This included only Class I malocclusion to any malocclusion. It assessed the
effects of MOPs coupled with a variety of orthodontic mechanics on either the retraction of maxillary
canines, the distalization of maxillary molars, or the modifications on premolar roots. Mostly,
variations in the number, location, and timing of MOPs impeded a global assessment. Overall, most
of the studies (six out of nine) reported moderately useful effects of MOPs, one was negative, and
only two found significant advantages of MOPs over conventional treatment. The review synthesized
the available evidence about MOP applications in orthodontics and identified some important
gaps in knowledge that could be starting points for a systematic review of the literature. In conclusion,
even if MOPs can accelerate tooth movements, the variety of aims and methods of the published
research prevents suggestion of their widespread use
Incidental Finding in Pre-Orthodontic Treatment Radiographs of an Aural Foreign Body: A Case Report
The presence of foreign bodies in the external auditory canal of young patients may cause,
if left untreated, severe permanent damage to the adjacent anatomical structures, and infections. A
10‐year‐old patient with an intellectual disability underwent orthodontic evaluation. An aural
radiopaque finding was visible in the lateral cephalogram and in the orthopantomography. The
patient’s mother reported that her son never showed any ear discomfort, except for a mild hearing
impairment that was never investigated. The patient was referred to an ear, nose and throat (ENT)
specialist that removed the foreign body located in the left external auditory meatus. The careful
evaluation of dental radiographs, including pre‐orthodontic and interim orthodontic radiographs,
may help to identify silent incidental findings that may otherwise lead to severe complications if
left untreated
Cone-Beam Computed Tomographic Assessment of the Mandibular Condylar Volume in Different Skeletal Patterns: A Retrospective Study in Adult Patients
The aim of this study was to assess the condylar volume in adult patients with different
skeletal classes and vertical patterns using cone‐beam computed tomography (CBCT). CBCT scans
of 146 condyles from 73 patients (mean age 30 12 years old; 49 female, 24 male) were selected from
the archive of the Department of Dentistry and Maxillofacial Surgery of Fondazione IRCCS Ca’
Granda, Milan, Italy, and retrospectively analyzed. The following inclusion criteria were used: adult
patients; CBCT performed with the same protocol (0.4 mm slice thickness, 16 22 cm field of view,
20 s scan time); no systemic diseases; and no previous orthodontic treatments. Three‐dimensional
cephalometric tracings were performed for each patient, the mandibular condyles were segmented
and the relevant volumes calculated using Mimics Materialize 20.0 software (Materialise, Leuven,
Belgium). Right and left variables were analyzed together using random‐intercept linear regression
models. No significant association between condylar volumes and skeletal class was found. On the
other hand, in relation to vertical patterns, the mean values of the mandibular condyle volumes in
hyperdivergent subjects (688 mm3) with a post‐rotation growth pattern (625 mm3) were smaller than in
hypodivergent patients (812 mm3) with a horizontal growth pattern (900 mm3). Patients with an increased
divergence angle had smaller condylar volumes than subjects with normal or decreased mandibular
plane divergence. This relationship may help the clinician when planning orthodontic treatment
Benefits and Implications of Resveratrol Supplementation on Microbiota Modulations: A Systematic Review of the Literature
Abstract: Resveratrol is a polyphenol that has been shown to possess many applications in different
fields of medicine. This systematic review has drawn attention to the axis between resveratrol and
human microbiota, which plays a key role in maintaining an adequate immune response that can
lead to different diseases when compromised. Resveratrol can also be an asset in new technologies,such as gene therapy. PubMed, Cochrane Library, Scopus, Web of Science, and Google Scholar were
searched to find papers that matched our topic dating from 1 January 2017 up to 18 January 2022,
with English‐language restriction using the following Boolean keywords: (“resveratrol” AND
“microbio*”). Eighteen studies were included as relevant papers matching the purpose of our
investigation. Immune response, prevention of thrombotic complications, microbiota, gene therapy,
and bone regeneration were retrieved as the main topics. The analyzed studies mostly involved
resveratrol supplementation and its effects on human microbiota by trials in vitro, in vivo, and ex
vivo. The beneficial activity of resveratrol is evident by analyzing the changes in the host’s genetic
expression and the gastrointestinal microbial community with its administration. The possibility of
identifying individual microbial families may allow to tailor therapeutic plans with targeted
polyphenolic diets when associated with microbial dysbiosis, such as inflammatory diseases of the
gastrointestinal tract, degenerative diseases, tumors, obesity, diabetes, bone tissue regeneration, and
metabolic syndrome
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
In-vitro dehydration kinetics coefficient of Kalifilcon A and other contact lens materials
Abstract In contact lens (CL) wear, dehydration needs to be tailored to avoid dryness and related symptoms. In this view, this work aims to assess and compare the in-vitro dehydration kinetics of five CL materials, including the newly developed Kalifilcon A CL. At 36 °C and 60% relative humidity, the in-vitro dehydration kinetics of the different CLs were compared using a gravimetric method. CLs were analyzed either after a rinse of a few seconds in preservative-free saline solution or after a 24-h incubation in the same solution. A model based on the Fick diffusion equation was employed to deduce a water kinetics coefficient, providing insights into water diffusion within the polymeric matrix. The study reveals that all materials exhibit a non-Fickian dehydration behavior, with significant differences in dehydration kinetics coefficients and dehydration rate slopes. Etafilcon A and Omafilcon A, both hydrogel CLs, exhibit a similar behavior, different compared to the pattern shown by Senofilcon A and Delefilcon A, silicone-hydrogel CLs. Notably, Kalifilcon A, despite being a silicone-hydrogel, displays a hydration behavior reminiscent of hydrogel CLs
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