scholarly journals Soft Lithography and Minimally Human Invasive Technique for Rapid Screening of Oral Biofilm Formation on New Microfabricated Dental Material Surfaces

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Marta Alvarez-Escobar ◽  
Sidónio C. Freitas ◽  
Derek Hansford ◽  
Fernando J. Monteiro ◽  
Alejandro Pelaez-Vargas
Keyword(s):  
Bacterial Adhesion ◽  
Soft Lithography ◽  
Dental Materials ◽  
Rapid Screening ◽  
Invasive Technique ◽  
Oral Biofilm ◽  
Pdms Surface ◽  
Flat Surfaces ◽  
The University ◽  
Present Pilot Study

Introduction. Microfabrication offers opportunities to study surface concepts focused to reduce bacterial adhesion on implants using human minimally invasive rapid screening (hMIRS). Wide information is available about cell/biomaterial interactions using eukaryotic and prokaryotic cells on surfaces of dental materials with different topographies, but studies using human being are still limited. Objective. To evaluate a synergy of microfabrication and hMIRS to study the bacterial adhesion on micropatterned surfaces for dental materials. Materials and Methods. Micropatterned and flat surfaces on biomedical PDMS disks were produced by soft lithography. The hMIRS approach was used to evaluate the total oral bacterial adhesion on PDMS surfaces placed in the oral cavity of five volunteers (the study was approved by the University Ethical Committee). After 24 h, the disks were analyzed using MTT assay and light microscopy. Results. In the present pilot study, microwell structures were microfabricated on the PDMS surface via soft lithography with a spacing of 5 µm. Overall, bacterial adhesion did not significantly differ between the flat and micropatterned surfaces. However, individual analysis of two subjects showed greater bacterial adhesion on the micropatterned surfaces than on the flat surfaces. Significance. Microfabrication and hMIRS might be implemented to study the cell/biomaterial interactions for dental materials.

scholarly journals A Concise Review of Silver Diamine Fluoride on Oral Biofilm

2021 ◽  
Vol 11 (7) ◽  
pp. 3232
Author(s):  
Jingyang Zhang ◽  
Sofiya-Roksolana Got ◽  
Iris Xiaoxue Yin ◽  
Edward Chin-Man Lo ◽  
Chun-Hung Chu
Keyword(s):  
Clinical Study ◽  
Streptococcus Mutans ◽  
Bacterial Adhesion ◽  
Clinical Studies ◽  
Antibacterial Properties ◽  
Tooth Surface ◽  
Original Research ◽  
Laboratory Studies ◽  
Oral Biofilm ◽  
Silver Diamine Fluoride

Studies have shown that silver diamine fluoride (SDF) is an effective agent to arrest and prevent dental caries due to its mineralizing and antibacterial properties. While plenty of studies have investigated the mineralizing properties, there are few papers that have examined its antibacterial effect on oral biofilm. The objective of this study was to identify the effect of silver diamine fluoride on oral biofilm. Method: The keywords used were (silver diamine fluoride OR silver diammine fluoride OR SDF OR silver fluoride OR AgF AND biofilm OR plaque). Two reviewers screened the titles and abstracts and then retrieved the full text of the potentially eligible publications. Publications of original research investigating the effect of SDF on oral biofilm were selected for this review. Results: This review included 15 laboratory studies and six clinical studies among the 540 papers identified. The laboratory studies found that SDF could prevent bacterial adhesion to the tooth surface. SDF also inhibited the growth of cariogenic bacteria, including Streptococcus mutans, Lactobacillus acidophilus, Streptococcus sobrinus, Lactobacillus rhamnosus, Actinomyces naeslundii, and Enterococcus faecalis, thus contributing to its success in caries arrest. One clinical study reported a decrease in Streptococcus mutans and Lactobacillus sp. in arrested caries after SDF treatment, and another clinical study found that SDF inhibited the growth of periodontitis microbiota, including Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia/nigrescens. However, three clinical studies reported no significant change in the microbial diversity of the plaque on the tooth after SDF treatment. Moreover, one laboratory study and one clinical research study reported that SDF inhibited the growth of Candida albicans. Conclusion: Not many research studies have investigated the effects of SDF on oral biofilm, although SDF has been used as a caries-arresting agent with antibacterial properties. However, a few publications have reported that SDF prevented bacterial adhesion to the teeth, inhibited the growth of cariogenic and periodontal bacteria, and possessed antifungal properties.

Non-invasive Prenatal Determination of Fetal Maturity

2016 ◽  
Vol 70 (3) ◽  
pp. 153-157
Author(s):  
Elena Dzikova ◽  
Goran Dimitrov ◽  
Olivera Stojceva-Taneva
Keyword(s):  
Gestational Age ◽  
Lamellar Body ◽  
Invasive Technique ◽  
Non Invasive ◽  
Gynecology And Obstetrics ◽  
Fetal Maturity ◽  
Invasive Method ◽  
The University ◽  
Body Count

Abstract Aims. The prenatal prediction of fetal maturity is very important, since neonatal respiratory distress syndrome (RDS) is one of the biggest causes of neonatal mortality. Our aim was to investigate a new non-invasive method for prediction of fetal maturity and to determine in which group according to gestational age of the fetus, the treatment works the best and in which cases it is necessary to be repeated. Methods. We examined 60 patients (30 with impending preterm delivery, divided in 3 groups: 28-30, 30-32, and 32-34 gestational weeks and 30 controls), at the University Clinic for Gynecology and Obstetrics, Medical Faculty, University “Ss. Cyril and Methodius”, Skopje, R. Macedonia. Fetal maturity was examined using ultrasound histogram from fetal lungs and liver, correlated with gestational age and postpartum RDS. Where possible, we performed amniocentesis for lamellar body count (LBC) to correlate our results with the current invasive method for prediction of fetal maturity. Results. Pre-therapy investigation showed a strong fetal immaturity in 28-32 weeks of gestation and less evident fetal immaturity in 32-34 weeks of gestation. Seventy-two hours post-treatment, fetal maturation was low in the first group, higher in the second and the highest in the third group. Amniocentesis for LBC showed correlation with the ultrasound results. Postpartum results were correlated with pre-delivery ultrasound and showed significance of p <0.05. Conclusion. The results obtained in our study were with high significance, and they were in correlation with other similar studies. However, more extensive investigations should be made to replace the current invasive technique.

Fabrication of Rough Polymer Surfaces Exhibiting Anti-reflective Properties

2015 ◽  
Vol 1728 ◽  
Author(s):  
Srinadh Mattaparthi ◽  
Chandra S. Sharma
Keyword(s):  
Solar Cells ◽  
Soft Lithography ◽  
Electrospun Nanofibers ◽  
Polymer Surfaces ◽  
Large Area ◽  
Engineering Applications ◽  
Pdms Surface ◽  
Hierarchical Roughness ◽  
Vis Spectroscopy ◽  
Wide Range

ABSTRACTWe have demonstrated some facile ways to fabricate the large area polymer surfaces with varying roughness followed by studying their anti-reflective properties. One of the approaches is based on electrospun nanofibers deposited on a substrate in an uneven non-woven matrix. This electrospun fabric was used as a master template to fabricate the negative replica of the fibers by soft lithography generating the roughness in polydimethylsiloxane (PDMS) surfaces. The second approach is based on biomimicking of flower petals. Petals are used as a master template to transfer surface features with hierarchical roughness over PDMS surface using replica moulding. As fabricated polymer surfaces with varied roughness have then tested for their anti-reflective properties using UV-VIS spectroscopy over a wide range of wavelengths and angles of incidence of light. These measurements show near zero reflection of patterned PDMS surfaces as compared to planar PDMS. This omnidirectional broadband anti-reflection behaviour of polymer surfaces can be used in wide variety of engineering applications including in solar cells.

scholarly journals You can run, but you can’t hide - A bitemark analysis

2021 ◽  
Vol 76 (3) ◽  
pp. 138-141
Author(s):  
Liam Robinson ◽  
Herman Bernitz
Keyword(s):  
Dental Materials ◽  
Forensic Odontology ◽  
Forensic Analysis ◽  
Blood Group Antigen ◽  
Abo Blood Group ◽  
Police Station ◽  
University Of Pretoria ◽  
Materials Used ◽  
The University ◽  
Plaster Models

All names and places have been changed to protect innocent victims in this case report. A young woman was returning home after work when she was accosted by a man wielding a knife. She was dragged into a nearby bush where the suspect attempted to rape her. She put up a substantial fight and was able to flee the scene. She went directly to the nearest police station to report the case. She was asked by the police to accompany them in the hope that she might recognise the suspect at the local taxi rank, which was near the scene of the crime. She did in fact recognise the suspect who was duly arrested. He denied any knowledge of the crime for which he was being apprehended. The victim informed the police that she had remembered biting the suspect on his right shoulder during the attack and ensuing struggle. The suspect was asked to roll up his right sleeve where a possible bitemark wound was observed. The suspect was taken into custody for further investigations. Fortunately, the police officer in charge of the case had attended a lecture on bitemarks given by the second author some weeks before the incident and was therefore well-versed in the protocol for the collection of evidence in a bitemark case. The officer arranged that photographs and impressions of the possible bitemark were taken for forensic analysis. Unfortunately, swobs of the bitemark were not conducted, therefore DNA and ABO blood group antigen analysis could not be performed. Impressions of the victim’s dentition were also taken from which plaster models were constructed. All dental materials used in this case were mixed according to the manufacturer’s instructions and were within their expiry dates. This evidence was submitted to the forensic odontology unit at the University of Pretoria for examination and comparative analysis

scholarly journals Classification and Properties of Dental Zirconia as Implant Fixtures and Superstructures

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4879
Author(s):  
Seiji Ban
Keyword(s):  
Mechanical Strength ◽  
Bacterial Adhesion ◽  
Contact Region ◽  
Dental Materials ◽  
Occlusal Contact ◽  
Suitable Material ◽  
Yttria Content ◽  
Occlusal Wear ◽  
Alumina Composites ◽  
Oral Condition

Various types of zirconia are widely used for the fabrication of dental implant superstructures and fixtures. Zirconia–alumina composites, such as ATZ and NanoZR, are adequate for implant fixtures because they have excellent mechanical strength in spite of insufficient esthetic properties. On the other hand, yttria-stabilized zirconia has been used for implant superstructures because of sufficient esthetic properties. They are classified to 12 types with yttria content, monochromatic/polychromatic, uniform/hybrid composition, and monolayer/multilayer. Zirconia with a higher yttria content has higher translucency and lower mechanical strength. Fracture strength of superstructures strongly depends on the strength on the occlusal contact region. It suggests that adequate zirconia should be selected as the superstructure crown, depending on whether strength or esthetics is prioritized. Low temperature degradation of zirconia decreases with yttria content, but even 3Y zirconia has a sufficient durability in oral condition. Although zirconia is the hardest dental materials, zirconia restorative rarely subjects the antagonist teeth to occlusal wear when it is mirror polished. Furthermore, zirconia has less bacterial adhesion and better soft tissue adhesion when it is mirror polished. This indicates that zirconia has advantageous for implant superstructures. As implant fixtures, zirconia is required for surface modification to obtain osseointegration to bone. Various surface treatments, such as roughening, surface activation, and coating, has been developed and improved. It is concluded that an adequately selected zirconia is a suitable material as implant superstructures and fixtures because of mechanically, esthetically, and biologically excellent properties.

scholarly journals Surface Modification by Combination of Dip-Pen Nanolithography and Soft Lithography for Reduction of Bacterial Adhesion

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Santiago Arango-Santander ◽  
Alejandro Pelaez-Vargas ◽  
Sidónio C. Freitas ◽  
Claudia García
Keyword(s):  
Stainless Steel ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Soft Lithography ◽  
Patterned Surfaces ◽  
Stainless Steel 316L ◽  
Viability Assay ◽  
Model Surfaces ◽  
Order Of Magnitude ◽  
Dip Pen Nanolithography

Dip-pen nanolithography (DPN) and soft lithography are techniques suitable to modify the surface of biomaterials. Modified surfaces might play a role in modulating cells and reducing bacterial adhesion and biofilm formation. The main objective of this study was threefold: first, to create patterns at microscale on model surfaces using DPN; second, to duplicate and transfer these patterns to a real biomaterial surface using a microstamping technique; and finally, to assess bacterial adhesion to these developed patterned surfaces using the cariogenic species Streptococcus mutans. DPN was used with a polymeric adhesive to create dot patterns on model surfaces. Elastomeric polydimethylsiloxane was used to duplicate the patterns and silica sol to transfer them to the medical grade stainless steel 316L surface by microstamping. Optical microscopy and atomic force microscopy (AFM) were used to characterize the patterns. S. mutans adhesion was assessed by colony-forming units (CFUs), MTT viability assay, and scanning electron microscopy (SEM). DPN allowed creating microarrays from 1 to 5 µm in diameter on model surfaces that were successfully transferred to the stainless steel 316L surface via microstamping. A significant reduction up to one order of magnitude in bacterial adhesion to micropatterned surfaces was observed. The presented experimental approach may be used to create patterns at microscale on a surface and transfer them to other surfaces of interest. A reduction in bacterial adhesion to patterned surfaces might have a major impact since adhesion is a key step in biofilm formation and development of biomaterial-related infections.

Management of Spacing in Mandibular Anterior Teeth by Minimally Invasive Technique Using Laminates: A Case Report

2019 ◽  
Vol 2 (2) ◽  
pp. 92-96
Author(s):  
Hema Agrawal ◽  
RK Singh ◽  
P Suwal ◽  
P Parajuli ◽  
IK Limbu ◽  
...  
Keyword(s):  
Case Report ◽  
Minimally Invasive ◽  
Dental Treatment ◽  
Dental Materials ◽  
Invasive Technique ◽  
Facial Appearance ◽  
Anterior Teeth ◽  
Personal Appearance ◽  
Laminate Veneers

People have become increasingly concerned about esthetics as a perfect smile gives patients more confidence and make them feel comfortable in social circumstances. Esthetic dental treatment plays an important role in improving personal appearance. Advances in dental materials have led to innovations in porcelain laminate veneers and bonding materials which has improved the overall quality of the esthetic restorations. This case report describes the rehabilitation of a patient with spacing in mandibularanterior teeth, who was concerned with his facial appearance, with ceramic laminate veneers.

scholarly journals Micro- and nano-surface structures based on vapor-deposited polymers

2017 ◽  
Vol 8 ◽  
pp. 1366-1374 ◽  
Author(s):  
Hsien-Yeh Chen
Keyword(s):  
Soft Lithography ◽  
Substrate Surface ◽  
Polymer Coatings ◽  
Substrate Material ◽  
Direct Writing ◽  
Selective Deposition ◽  
Flat Surfaces ◽  
Patterned Structures ◽  
Surface Patterns ◽  
Deposition Processes

Vapor-deposition processes and the resulting thin polymer films provide consistent coatings that decouple the underlying substrate surface properties and can be applied for surface modification regardless of the substrate material and geometry. Here, various ways to structure these vapor-deposited polymer thin films are described. Well-established and available photolithography and soft lithography techniques are widely performed for the creation of surface patterns and microstructures on coated substrates. However, because of the requirements for applying a photomask or an elastomeric stamp, these techniques are mostly limited to flat substrates. Attempts are also conducted to produce patterned structures on non-flat surfaces with various maskless methods such as light-directed patterning and direct-writing approaches. The limitations for patterning on non-flat surfaces are resolution and cost. With the requirement of chemical control and/or precise accessibility to the linkage with functional molecules, chemically and topographically defined interfaces have recently attracted considerable attention. The multifunctional, gradient, and/or synergistic activities of using such interfaces are also discussed. Finally, an emerging discovery of selective deposition of polymer coatings and the bottom-up patterning approach by using the selective deposition technology is demonstrated.

scholarly journals Molecular Interactions between Saliva and Dental Composites Resins: A Way Forward

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2537
Author(s):  
Veaceslav Șaramet ◽  
Marina Meleșcanu-Imre ◽  
Ana Maria Cristina Țâncu ◽  
Crenguța Cristina Albu ◽  
Alexandra Ripszky-Totan ◽  
...  
Keyword(s):  
Dental Materials ◽  
Composite Resins ◽  
Dental Composite ◽  
Dental Composites ◽  
Oral Biofilm ◽  
Oxidative Stress Biomarkers ◽  
Cytotoxic Effects ◽  
Stress Biomarkers ◽  
Dental Composite Resins ◽  
Molecular Landscape

Dentin and enamel loss related to trauma or especially caries is one of the most common pathological issues in dentistry that requires restoration of the teeth by using materials with appropriate properties. The composite resins represent dental materials with significant importance in today’s dentistry, presenting important qualities, including their mechanical behavior and excellent aesthetics. This paper focuses on the saliva interactions with these materials and on their biocompatibility, which is continuously improved in the new generations of resin-based composites. Starting from the elements involved on the molecular landscape of the dental caries process, the paper presents certain strategies for obtaining more advanced new dental composite resins, as follows: suppression of oral biofilm acids formation, promotion of remineralization process, counteraction of the proteolytic attack, and avoidance of cytotoxic effects; the relation between dental composite resins and salivary oxidative stress biomarkers is also presented in this context.

scholarly journals Fabrication and Hydrodynamic Characterization of a Microfluidic Device for Cell Adhesion Tests in Polymeric Surfaces

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 303 ◽  
Author(s):  
J. Ponmozhi ◽  
J. M. R. Moreira ◽  
F. J. Mergulhão ◽  
J. B. L. M. Campos ◽  
J. M. Miranda
Keyword(s):  
Cell Adhesion ◽  
Microfluidic Device ◽  
Bacterial Adhesion ◽  
Soft Lithography ◽  
Region Of Interest ◽  
Polymeric Materials ◽  
Fabrication Method ◽  
Major Drawback ◽  
Polymeric Surfaces ◽  
Rectangular Channels

A fabrication method is developed to produce a microfluidic device to test cell adhesion to polymeric materials. The process is able to produce channels with walls of any spin coatable polymer. The method is a modification of the existing poly-dimethylsiloxane soft lithography method and, therefore, it is compatible with sealing methods and equipment of most microfluidic laboratories. The molds are produced by xurography, simplifying the fabrication in laboratories without sophisticated equipment for photolithography. The fabrication method is tested by determining the effective differences in bacterial adhesion in five different materials. These materials have different surface hydrophobicities and charges. The major drawback of the method is the location of the region of interest in a lowered surface. It is demonstrated by bacterial adhesion experiments that this drawback has a negligible effect on adhesion. The flow in the device was characterized by computational fluid dynamics and it was shown that shear stress in the region of interest can be calculated by numerical methods and by an analytical equation for rectangular channels. The device is therefore validated for adhesion tests.

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