Reinforcement of photosensitive material for bases of orthodontic appliances

Conductor, resistor, and dielectric patterns of microelectronic device are usually defined by exposure of a photosensitive material through a mask onto the device with subsequent development of the photoresist and chemical removal of the undesired materials. Standard optical techniques are limited and electron lithography provides several important advantages, including the ability to expose features as small as 1,000 Å, and direct exposure on the wafer with no intermediate mask. This presentation is intended to report how electron lithography was used to define the permalloy patterns which are used to manipulate domains in magnetic bubble memory devices.The electron optical system used in our experiment as shown in Fig. 1 consisted of a high resolution scanning electron microscope, a computer, and a high precision motorized specimen stage. The computer is appropriately interfaced to address the electron beam, control beam exposure, and move the specimen stage.

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Accuracy Evaluation of Additively and Subtractively Fabricated Palatal Plate Orthodontic Appliances for Newborns and Infants–An In Vitro Study

Materials ◽

10.3390/ma14154103 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4103

Author(s):

Maite Aretxabaleta ◽

Alexey Unkovskiy ◽

Bernd Koos ◽

Sebastian Spintzyk ◽

Alexander B. Xepapadeas

Keyword(s):

Layer Thickness ◽

In Vitro Study ◽

Orthodontic Appliances ◽

Accuracy Evaluation ◽

Palatal Plate ◽

Cad Cam ◽

Subtractive Manufacturing ◽

Palatal Stimulation ◽

Manufacturing Time

Different approaches for digital workflows have already been presented for their use in palatal plates for newborns and infants. However, there is no evidence on the accuracy of CAD/CAM manufactured orthodontic appliances for this kind of application. This study evaluates trueness and precision provided by different CAM technologies and materials for these appliances. Samples of a standard palatal stimulation plate were manufactured using stereolithography (SLA), direct light processing (DLP) and subtractive manufacturing (SM). The effect of material (for SM) and layer thickness (for DLP) were also investigated. Specimens were digitized with a laboratory scanner (D2000, 3Shape) and analyzed with a 3D inspection software (Geomagic Control X, 3D systems). For quantitative analysis, differences between 3D datasets were measured using root mean square (RMS) error values for trueness and precision. For qualitative analysis, color maps were generated to detect locations of deviations within each sample. SM showed higher trueness and precision than AM technologies. Reducing layer thickness in DLP did not significantly increase accuracy, but prolonged manufacturing time. All materials and technologies met the clinically acceptable range and are appropriate for their use. DLP with 100 µm layer thickness showed the highest efficiency, obtaining high trueness and precision within the lowest manufacturing time.

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Comparative Analysis of Periodontal Pain According to the Type of Precision Orthodontic Appliances: Vestibular, Lingual and Aligners. A Prospective Clinical Study

Biology ◽

10.3390/biology10050379 ◽

2021 ◽

Vol 10 (5) ◽

pp. 379

Author(s):

Laura Antonio-Zancajo ◽

Javier Montero ◽

Daniele Garcovich ◽

Mario Alvarado-Lorenzo ◽

Alberto Albaladejo ◽

...

Keyword(s):

Clinical Study ◽

Pain Intensity ◽

Short Form ◽

Study Groups ◽

Mcgill Pain Questionnaire ◽

Prospective Clinical Study ◽

Orthodontic Appliances ◽

Low Friction ◽

Different Types ◽

Lower Arch

The objective of this prospective clinical study was to analyze the pain (intensity, location and type) that patients presented after the placement of different types of orthodontic appliances: conventional, low friction, lingual and aligners. The sample consisted of 120 patients divided into four groups: conventional (CON), low friction (LF), lingual (LO) and aligners (INV). The participants were given the Short-Form McGill Pain Questionnaire (Ortho-SF-MPQ), where they had to record the pain intensity (no pain, mild, moderate or intense) and the periodontal location at different time points, from the first 4 h to 7 days after the start of treatment. In all the study groups, the most frequent location was both anterior arches, with maximum values between 56.7% (CON group at 24 h) and 30% (LO group at 4 h). The “whole mouth” and “complete lower arch” locations were indicated only by the patients in the lingual group. Regarding pain intensity, the patients reported a higher percentage of mild–moderate pain during the first 3 days of treatment (96.7% in LO at 4 h, 86.7% in CON, 83.3% in LF and 90% in INV at 24 h); later, the reported pain decreased to no pain/mild pain, especially in the lingual group, until reaching values close to zero at 7 days post-treatment. The most frequent type of pain was acute in the low friction and lingual groups (with maxima of 60% and 46.7% at 24 h, respectively). On the contrary, in the conventional (36.7% at 4 h) and Invisalign (40% at 24 h) groups, the sensitive type was the most frequent. There are differences regarding periodontal pain in its intensity, location and type according to the use of different orthodontic techniques.

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In Vitro Ion Release of Wires in Removable Orthodontic Appliances

Materials ◽

10.3390/ma14123402 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3402

Author(s):

Lena Wepner ◽

Harald Andreas Färber ◽

Andreas Jaensch ◽

Anna Weber ◽

Florian Heuser ◽

...

Keyword(s):

Mechanical Loading ◽

Corrosive Medium ◽

Inductively Coupled Plasma ◽

Petri Dish ◽

Orthodontic Appliances ◽

Testing Time ◽

Ion Release ◽

Inductively Coupled ◽

Corrosive Solution

Various orthodontic wire compositions and configurations are present on the market for removable appliances; however, there have still been only few studies focusing on the effect of resin color and additives such as glitter on corrosion of metallic wires under different conditions. Thus, the aim of the study was to compare concentrations of released ions (aluminium, chromium, nickel) in a corrosive medium under three different conditions: non-loaded wires, loaded wires, and non-loaded wires treated with Kukis® cleaning tablets. Six different wires made of three types of steel alloy were embedded in PMMA resin leaving one centimetre of each wire emerging from the resin to come into contact with the corrosive medium. Glitter particles were added to half of the produced test specimens. For the unloaded test series, five specimens of each group were covered in a petri dish with 50 mL of corrosive medium (pH 2.3) following EN-ISO 10271 for seven days at 37 °C. The wires for the mechanically loaded test specimens overlapped the resin by 5 cm and were clamped into a time-switched electric drive for a defined period of time before the samples were taken after a testing time of 7 days. In the third group, unloaded test specimens were transferred from their petri dishes into the prepared Kukis® solution every 24 h before being stored in the corrosive medium. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the specific ions in the corrosive solution. Statistical analysis showed that the mechanical loading of all wires could significantly raise the diffusion of ions into the corrosive medium. The colour of the resin did not affect the concentration of the released ions. The Kukis® cleaning tabs could not lower the corrosion of the tested metals, as some of the wires were corroded even more using the brace cleanser. Glitter-containing test specimens showed significantly higher amounts of aluminium. Mechanical loading as well as the presence of glitter particles in the resin significantly affected ion concentrations.

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The impact of fixed orthodontic appliances on oral microbiome dynamics in Japanese patients

Scientific Reports ◽

10.1038/s41598-020-78971-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Isamu Kado ◽

Junzo Hisatsune ◽

Keiko Tsuruda ◽

Kotaro Tanimoto ◽

Motoyuki Sugai

Keyword(s):

Relative Abundance ◽

Japanese Patients ◽

Oral Microbiome ◽

Orthodontic Appliances ◽

Periodontal Pathogens ◽

Supragingival Plaque ◽

Fixed Orthodontic Appliances ◽

Microbial Dna ◽

The Impact ◽

Level Analysis

AbstractFixed orthodontic appliances are common and effective tools to treat malocclusion. Adverse effects of these appliances, such as dental caries and periodontitis, may be associated with alteration of the microbiome. This study investigated the impact of these appliances on the dynamics of the oral microbiome. Seventy-one patients were selected. Supragingival plaque samples were collected before placement (T0) and six months after placement (T1). Saliva samples were collected at T0 and T1, and then when appliance removal (T2). Microbial DNA was analyzed by 16S rRNA meta-sequencing. The diversity analysis indicated dynamic changes in the structure of the oral microbiome. Taxonomic analysis at phylum level showed a significant increase in Bacteroidetes and Saccharibacteria (formally TM7) and decrease in Proteobacteria and Actinobacteria over time, in both plaque and saliva. Genus level analysis of relative abundance indicated a significant increase in anaerobic and facultative anaerobes in both plaque and saliva. Fixed orthodontic appliances induced measurable changes in the oral microbiome. This was characterized by an increase in relative abundance of obligate anaerobes, including periodontal pathogens. It can be concluded that this dysbiosis induced by fixed orthodontic appliances is likely to represent a transitional stage in the shift in microbiome from healthy to periodontitis.

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Real-time characterization of gelatin doped with potassium dichromate as a photosensitive material

Optik ◽

10.1016/j.ijleo.2021.167310 ◽

2021 ◽

pp. 167310

Author(s):

Yenisey Ponce de León ◽

Beatriz Montaño Flores ◽

Mauricio Ortiz-Gutiérrez ◽

Juan Carlos Ibarra Torres ◽

Mario Pérez Cortés

Keyword(s):

Real Time ◽

Potassium Dichromate ◽

Photosensitive Material

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Nanomaterials Application in Orthodontics

Nanomaterials ◽

10.3390/nano11020337 ◽

2021 ◽

Vol 11 (2) ◽

pp. 337

Author(s):

Wojciech Zakrzewski ◽

Maciej Dobrzynski ◽

Wojciech Dobrzynski ◽

Anna Zawadzka-Knefel ◽

Mateusz Janecki ◽

...

Keyword(s):

Friction Force ◽

Material Properties ◽

Orthodontic Treatment ◽

Mechanical Characteristics ◽

Current Knowledge ◽

Scientific Work ◽

Orthodontic Appliances ◽

Orthodontic Movement ◽

Enamel Demineralization

Nanotechnology has gained importance in recent years due to its ability to enhance material properties, including antimicrobial characteristics. Nanotechnology is applicable in various aspects of orthodontics. This scientific work focuses on the concept of nanotechnology and its applications in the field of orthodontics, including, among others, enhancement of antimicrobial characteristics of orthodontic resins, leading to reduction of enamel demineralization or control of friction force during orthodontic movement. The latter one enables effective orthodontic treatment while using less force. Emphasis is put on antimicrobial and mechanical characteristics of nanomaterials during orthodontic treatment. The manuscript sums up the current knowledge about nanomaterials’ influence on orthodontic appliances.

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Functionalized Chitosan Nanomaterials: A Jammer for Quorum Sensing

Polymers ◽

10.3390/polym13152533 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2533

Author(s):

Moupriya Nag ◽

Dibyajit Lahiri ◽

Dipro Mukherjee ◽

Ritwik Banerjee ◽

Sayantani Garai ◽

...

Keyword(s):

Drug Resistance ◽

Quorum Sensing ◽

Targeted Delivery ◽

Direct Interaction ◽

Orthodontic Appliances ◽

Chronic Infections ◽

Functionalized Nanomaterials ◽

Low Toxicity ◽

Novel Target ◽

Positively Charged

The biggest challenge in the present-day healthcare scenario is the rapid emergence and spread of antimicrobial resistance due to the rampant use of antibiotics in daily therapeutics. Such drug resistance is associated with the enhancement of microbial virulence and the acquisition of the ability to evade the host’s immune response under the shelter of a biofilm. Quorum sensing (QS) is the mechanism by which the microbial colonies in a biofilm modulate and intercept communication without direct interaction. Hence, the eradication of biofilms through hindering this communication will lead to the successful management of drug resistance and may be a novel target for antimicrobial chemotherapy. Chitosan shows microbicidal activities by acting electrostatically with its positively charged amino groups, which interact with anionic moieties on microbial species, causing enhanced membrane permeability and eventual cell death. Therefore, nanoparticles (NPs) prepared with chitosan possess a positive surface charge and mucoadhesive properties that can adhere to microbial mucus membranes and release their drug load in a constant release manner. As the success in therapeutics depends on the targeted delivery of drugs, chitosan nanomaterial, which displays low toxicity, can be safely used for eradicating a biofilm through attenuating the quorum sensing (QS). Since the anti-biofilm potential of chitosan and its nano-derivatives are reported for various microorganisms, these can be used as attractive tools for combating chronic infections and for the preparation of functionalized nanomaterials for different medical devices, such as orthodontic appliances. This mini-review focuses on the mechanism of the downregulation of quorum sensing using functionalized chitosan nanomaterials and the future prospects of its applications.

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Duration of orthodontic treatment with fixed appliances in adolescents and adults: a systematic review with meta-analysis

Progress in Orthodontics ◽

10.1186/s40510-020-00334-4 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Allen Abbing ◽

Vasiliki Koretsi ◽

Theodore Eliades ◽

Spyridon N. Papageorgiou

Keyword(s):

Treatment Duration ◽

Meta Analysis ◽

Risk Of Bias ◽

Adult Patients ◽

Comprehensive Treatment ◽

Orthodontic Appliances ◽

Duration Of Treatment ◽

Quality Of Evidence ◽

Fixed Appliances

Abstract Objectives Adults with fixed orthodontic appliances are increasing nowadays. Compared with adolescents, adults present biological differences that might influence treatment duration. Therefore, the aim of the study was to compare duration of treatment with fixed appliances between adults and adolescents. Materials and methods Eight databases were searched up to September 2019 for randomized and non-randomized clinical studies comparing treatment duration with fixed appliances in adolescents and adult patients. After duplicate study selection, data extraction, and risk of bias assessment with the Cochrane ROBINS-I tool, random effects meta-analyses of mean differences (MD) and their 95% confidence intervals (CIs) were performed, followed by assessment of the quality of evidence with GRADE. Results A total of 11 unique studies (one prospective and 10 retrospective non-randomized) with 2969 adolescents and 1380 adult patients were finally included. Meta-analysis of 7 studies found no significant difference in the duration of comprehensive treatment with fixed appliances (MD = − 0.8 month; 95% CI = − 4.2 to 2.6 months; P = 0.65; I2 = 92%) between adults and adolescents. Similarly, both distalization of upper first molars with skeletal anchorage for class II correction and the retraction of canines into the premolar extraction spaces lasted similarly long among adults and adolescents. On the other hand, alignment of palatally displaced canines lasted considerably longer in adults compared to adolescents (1 study; MD = 3.8 months; 95% CI = 1.4 to 6.2 months; P = 0.002). The quality of evidence for the meta-analysis was low due to the inclusion of non-randomized studies with considerable risk of bias. Conclusions While existing evidence does not indicate a difference in the overall duration of treatment with fixed appliances between adults and adolescents, the alignment of palatally displaced canines lasted significantly longer in adults. However, our confidence in these estimates is low due to the risk of bias in the included studies. Trial registration PROSPERO: (CRD42019148169)

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Orthodontic Aligner Incorporating Eucommia ulmoides Exerts Low Continuous Force: In Vitro Study

Materials ◽

10.3390/ma13184085 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4085

Author(s):

Sayuri Inoue ◽

Satoshi Yamaguchi ◽

Hiroshi Uyama ◽

Takashi Yamashiro ◽

Satoshi Imazato

Keyword(s):

Water Immersion ◽

In Vitro Study ◽

Nickel Titanium ◽

Orthodontic Appliances ◽

Orthodontic Appliance ◽

Measuring Device ◽

Orthodontic Force ◽

Custom Made ◽

Titanium Wire

The aim of this study was to investigate the orthodontic force exerted by thermoplastic orthodontic appliances incorporating Eucommiaulmoides in terms of usefulness as the aligner-type orthodontic device. Erkodur, Essix C+®, Eucommia elastomer, and edgewise brackets were used (n = 3, each; thickness = 1.0 mm, each). The orthodontic force on the upper right incisor was measured every 24 h for two weeks using a custom-made measuring device. The force of the Eucommia elastomer (4.25 ± 0.274 N) and multi bracket system (5.32 ± 0.338 N) did not change from the beginning to the end (p > 0.01). The orthodontic force exerted by the Eucommia elastomer was lower than that of the multi-bracket orthodontic appliance from the beginning to the end. The force of Erkodur significantly decreased from the beginning to 24 h (6.47 ± 1.40 N) and 48 h (3.30 ± 0.536 N) (p < 0.01). The force of Essix C+® significantly decreased from the beginning (13.2 ± 0.845 N) to 24 h (8.77 ± 0.231 N) (p < 0.01). The thermoplastic orthodontic appliance made of Eucommia elastomer continuously exerted a constant orthodontic force for two weeks under water immersion conditions. The orthodontic force of Eucommia elastomer was found to be similar to the orthodontic force exerted by the multi-bracket orthodontic appliance with 0.019 × 0.025 in nickel–titanium wire. These results suggest that the Eucommia elastomer has possibly become one of the more useful materials to form thermoplastic orthodontic appliance exerting low continues orthodontic force.

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