scholarly journals Micromechanical and Structural Analysis of Compromised Dental Tissues

2005 ◽  
Vol 898 ◽  
Author(s):  
Erin Mahoney ◽  
Nicky Kilpatrick ◽  
Michael Swain
Keyword(s):  
Structural Analysis ◽  
Clinical Outcomes ◽  
Traditional Method ◽  
Dental Materials ◽  
Clinical Approach ◽  
Treatment Technique ◽  
Dental Tissues ◽  
Treatment Techniques ◽  
Materials Research

AbstractWith the continual development of new dental materials and treatment techniques, dental materials research is now more important than ever. Although the traditional method of materials and treatment technique assessment was laboratory based, there is a need for investigations into the clinical outcomes of in-vitro research. The aim of this paper is to discuss the micromechanical and structural analysis of compromised dental tissues that affect young children, using a biomaterial and clinical approach.

Evaluation of Fluoride-Releasing Dental Materials by Means of in Vitro and in Vivo Demineralization Models: Reaction Paper

1995 ◽  
Vol 9 (3) ◽  
pp. 324-331 ◽  
Author(s):  
H. Ralph Rawls
Keyword(s):  
Clinical Efficacy ◽  
Dental Materials ◽  
Model Systems ◽  
Intimate Contact ◽  
Minimum Concentration ◽  
Dental Tissues ◽  
Caries Model ◽  
Target Values

It is essential that we understand the dose-response mechanisms of fluoride delivered intra-orally at sites in intimate contact with dental tissues. Many studies show that extremely low levels of fluoride can inhibit caries. However, few of these studies provide a direct comparison between fluoride release and the inhibition of secondary caries. For this, laboratory, animal, and in situ caries models are required which can predict clinical efficacy. This paper supplements Dr. Erickson's presentation (Erickson and Glasspoole, 1995) by illustrating the adaptation of currently used demineralization and caries models to the development and evaluation of fluoride-containing resin materials. As representative of this class of material, those which release by ion-exchange are reviewed. It is concluded that model systems designed for topical fluorides and non-fluoride dental materials can be adapted for use with fluoride-releasing materials. Further, the use of materials with a long history of clinical efficacy as inhibitors of marginal caries, such as the silicates, is a useful means of determining target values for developing new fluoride-releasing materials. The minimum concentration of F- that must be maintained in the immediate vicinity of a material to provide caries protection at localized sites is not yet known. Nor is it known what combination of release rate, pattern of release, and duration of release is needed to optimize either localized or full-mouth protection. These issues deserve closer examination to aid our understanding of F- action when delivered from dental materials, so that improved caries model systems can be designed for use with dental materials.

scholarly journals Intelligent automation of dental material analysis using robotic arm with Jerk optimized trajectory

2020 ◽  
Vol 11 (12) ◽  
pp. 6223-6234 ◽  
Author(s):  
Robertas Damaševičius ◽  
Rytis Maskeliūnas ◽  
Gintautas Narvydas ◽  
Rūta Narbutaitė ◽  
Dawid Połap ◽  
...  
Keyword(s):  
Dental Materials ◽  
Robotic Arm ◽  
Medium Size ◽  
Robot Arm ◽  
Robotic Platform ◽  
Nsga Ii ◽  
Dental Tissues ◽  
Pareto Optimal Set ◽  
Thermal Wear

AbstractMany types of biomaterial analysis require numerous repetition of the same operations. We suggest applying the principles of Total Laboratory Automation (TLA) for analysis of dental tissues in in-vitro conditions. We propose an innovative robotic platform with ABB high precision industrial robotic arm. We programmed the robot to achieve 3000 cycles of submerging for analysis of the stability and thermal wear of dental adhesive materials. We address the problem of robot trajectory planning to achieve smooth and precise trajectory while minimizing jerk. We generate different variants of trajectory using natural cubic splines and adopt the NSGA II multiobjective evolutionary algorithm to find a Pareto-optimal set of robot arm trajectories. The results demonstrate the applicability of the developed robotic platform for in-vitro experiments with dental materials. The platform is suitable for small or medium size dental laboratories.

scholarly journals Stereomicroscopic analysis of dental materials employed in endodontic exposed to high temperatures

2017 ◽  
Vol 19 (2) ◽  
Author(s):  
Johanna Aramburo ◽  
Angela Zapata ◽  
Sugey Zúñiga ◽  
Freddy Moreno
Keyword(s):  
High Temperatures ◽  
Dental Materials ◽  
In Vitro Study ◽  
Human Teeth ◽  
Great Resistance ◽  
Dental Tissues ◽  
Specific Rank ◽  
Hard Dental Tissues ◽  
Physical Changes

Objective: To describe the physical estereomicroscopical changes that occur in dental tissues and materials employed in a conventional endodontic treatment after application of high temperatures. Materials and methods: An in Vitro study was carried out to observe microscopic, structural and physical changes on hard dental tissues (enamel, dentine and cement) and on endodontic materials (gutta-percha Maillefer Dentsply®, endodontical cement based on oxide of zinc-eugenol Eufar®, cement based on epoxic resin Top Seal® Dentsply®, glass ionomer Fuji I® GC America®, silver amalgam GS80® SDI® and composite Point 4® Kerr®) in 124 human teeth, submitted to five temperature ranks (200ºC, 400ºC, 600ºC, 800ºC, 1000ºC). Results: The studied tissues and dental materials presented great resistance to the high temperatures without varying considerably their micro structure, such as that the physical changes (dimensional stability, cracks, pits, fractures, texture, color, carbonization and incineration) can be observed through estereomicrophotographies and can be associated to each specific rank of temperature. Conclusions: Some macrostructural changes of dental tissues and the dental materials occur of specific form in each rank of temperature, and for this reason they can be employed in the comparison before and postmortem during the process of identification of burned or charred corpse and human remains. Key words: Forensic dentistry, human identification, stereomicroscopy, dental materials, high temperatures.

scholarly journals Macroscopic in vitro analysis of titanium and fiberglass posts cemented in human premolars subjected to high temperatures for forensic purposes

2017 ◽  
Vol 21 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Johanna Aramburo ◽  
Herney Garzón ◽  
Juán Camilo Rivera ◽  
Sebastián Medina ◽  
Freddy Moreno
Keyword(s):  
High Temperatures ◽  
Dental Materials ◽  
Human Teeth ◽  
Dental Tissues ◽  
Gutta Percha ◽  
Vitro Analysis ◽  
Physical Changes ◽  
Study Offer ◽  
In Vitro Analysis

SUMMARYObjective: To describe the macroscopicchanges of titanium and fiberglass postscemented in human premolars subjectedto high temperatures for forensic purposes.Materials and methods: An in Vitro experimentalstudy was conducted to observethe macroscopic physical changes of dentaltissues (enamel, dentine and cement), ofmaterials of conventional endodontic use(gutta-percha Wave One® Maillefer Dentsply®, endodontic cement with epoxic resinTop Seal® Maillefer Dentsply®), postscement Relyx TM ARC 3M ESPE®) andof the titanium posts (Tenax® EndodonticPost System Coltene®) and fiberglassposts (Tenax® Fiber Trans Coltene®) in124 human teeth, exposed to five ranks oftemperature 200ºC, 400ºC, 600ºC, 800ºC,1000ºC (three teeth at each temperature).Results: The studied tissues and dentalmaterials used in this study, offer greatresistance to high temperatures, exhibitingconsiderably variation of their macrostructure,in a way that the physical changes(dimensional stability, fissures, cracks,fractures, texture, color, carbonization andincineration) can serve to identify them andto associate such changes to each rank ofspecific temperature.Conclusion: The titanium and fiberglassposts cemented in human premolars offergreat resistance to the action of high tem-peratures. In the same way, they presentspecific changes associated to the dentaltissues that can contribute with the processof identification and medico-legal necropsyof a corpse or burned, incinerated or carbonizedhuman rests.Key words: Forensic dentistry, humanidentification, dental tissues, dental materials,endodontics, high temperatures.

scholarly journals Disulfide HMGB1 acts via TLR2/4 receptors to reduce the numbers of oligodendrocyte progenitor cells after traumatic injury in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Ved ◽  
F. Sharouf ◽  
B. Harari ◽  
M. Muzaffar ◽  
S. Manivannan ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Culture Medium ◽  
Traumatic Injury ◽  
High Mobility ◽  
Oligodendrocyte Progenitor Cells ◽  
Therapeutic Approaches ◽  
Mature Oligodendrocyte ◽  
Oligodendrocyte Progenitor ◽  
Tlr Signalling

AbstractTraumatic brain injury (TBI) is associated with poor clinical outcomes; autopsy studies of TBI victims demonstrate significant oligodendrocyte progenitor cell (OPC) death post TBI; an observation, which may explain the lack of meaningful repair of injured axons. Whilst high-mobility group box-1 (HMGB1) and its key receptors TLR2/4 are identified as key initiators of neuroinflammation post-TBI, they have been identified as attractive targets for development of novel therapeutic approaches to improve post-TBI clinical outcomes. In this report we establish unequivocal evidence that HMGB1 released in vitro impairs OPC response to mechanical injury; an effect that is pharmacologically reversible. We show that needle scratch injury hyper-acutely induced microglial HMGB1 nucleus-to-cytoplasm translocation and subsequent release into culture medium. Application of injury-conditioned media resulted in significant decreases in OPC number through anti-proliferative effects. This effect was reversed by co-treatment with the TLR2/4 receptor antagonist BoxA. Furthermore, whilst injury conditioned medium drove OPCs towards an activated reactive morphology, this was also abolished after BoxA co-treatment. We conclude that HMGB1, through TLR2/4 dependant mechanisms, may be detrimental to OPC proliferation following injury in vitro, negatively affecting the potential for restoring a mature oligodendrocyte population, and subsequent axonal remyelination. Further study is required to assess how HMGB1-TLR signalling influences OPC maturation and myelination capacity.

scholarly journals Removal of Toxic Elements and Microbial Contaminants from Groundwater Using Low-Cost Treatment Options

2021 ◽  
Author(s):  
Dana A. Da’ana ◽  
Nabil Zouari ◽  
Mohammad Y. Ashfaq ◽  
Mohammed Abu-Dieyeh ◽  
Majeda Khraisheh ◽  
...  
Keyword(s):  
Cost Analysis ◽  
Toxic Elements ◽  
Low Cost ◽  
Treatment Technique ◽  
Groundwater Treatment ◽  
Efficient Treatment ◽  
Treatment Techniques ◽  
Cost Treatment ◽  
Treatment Technologies ◽  
Microbial Contaminants

Abstract Purpose of Review This paper reviews various low-cost treatment techniques such as adsorption, permeable reactive barrier, and biological techniques for the simultaneous removal of chemical and microbial contaminants from groundwater and discusses treatment mechanisms of different treatment techniques. This paper also discusses the challenges of groundwater treatment, how to choose the appropriate treatment technique, and cost analysis of groundwater treatment. Recent Findings Various treatment technologies have been used for the treatment of groundwater: physical, chemical, and biological technologies with different success rates. In the literature, various adsorbents have been successfully synthesized from low-cost and environmentally friendly materials. Adsorption is considered an efficient treatment technique for the removal of both toxic elements and pathogens by utilizing different adsorbents. For example, the nanostructures of MgO with a BET surface area of up to 171 m2/g obtained a very high adsorption capacity of 29,131 mg/g for fluoride ions in water, while the incorporation of iron in activated carbon has improved its adsorption capacity to 51.3 mg/g for arsenic. Moreover, certain adsorbents have shown the capability to remove 99% of the rotavirus and adenovirus from groundwater. Summary Groundwater resources are contaminated with toxic metals and pathogens. Therefore, water treatment technologies should be evaluated for their efficiency to remove such contaminants. Determination of the most cost-effective and efficient treatment technique is not an easy task and requires the understanding of various aspects such as the contaminants present in water, the reuse options considered, and cost analysis of the treatment technique.

scholarly journals In Silico Structural Modeling and Analysis of Interactions of Tremellomycetes Cytochrome P450 Monooxygenases CYP51s with Substrates and Azoles

2021 ◽  
Vol 22 (15) ◽  
pp. 7811
Author(s):  
Olufunmilayo Olukemi Akapo ◽  
Joanna M. Macnar ◽  
Justyna D. Kryś ◽  
Puleng Rosinah Syed ◽  
Khajamohiddin Syed ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Structural Analysis ◽  
In Silico ◽  
Web Application ◽  
Cytochrome P450 Monooxygenases ◽  
Agglomerative Clustering ◽  
Ligand Complex ◽  
P450 Monooxygenase ◽  
Study Results

Cytochrome P450 monooxygenase CYP51 (sterol 14α-demethylase) is a well-known target of the azole drug fluconazole for treating cryptococcosis, a life-threatening fungal infection in immune-compromised patients in poor countries. Studies indicate that mutations in CYP51 confer fluconazole resistance on cryptococcal species. Despite the importance of CYP51 in these species, few studies on the structural analysis of CYP51 and its interactions with different azole drugs have been reported. We therefore performed in silico structural analysis of 11 CYP51s from cryptococcal species and other Tremellomycetes. Interactions of 11 CYP51s with nine ligands (three substrates and six azoles) performed by Rosetta docking using 10,000 combinations for each of the CYP51-ligand complex (11 CYP51s × 9 ligands = 99 complexes) and hierarchical agglomerative clustering were used for selecting the complexes. A web application for visualization of CYP51s’ interactions with ligands was developed (http://bioshell.pl/azoledocking/). The study results indicated that Tremellomycetes CYP51s have a high preference for itraconazole, corroborating the in vitro effectiveness of itraconazole compared to fluconazole. Amino acids interacting with different ligands were found to be conserved across CYP51s, indicating that the procedure employed in this study is accurate and can be automated for studying P450-ligand interactions to cater for the growing number of P450s.

The Toxic Effects of Two Dental Materials on Human Buccal Epithelium In Vitro and Monkey Buccal Epithelium In Vivo

1987 ◽  
Vol 14 (3) ◽  
pp. 166-167
Author(s):  
D. Arenholt-Bindslev ◽  
P. Hørsted-Bindslev ◽  
H.P. Philipsen
Keyword(s):  
Dental Materials ◽  
Microscopical Examination ◽  
Buccal Epithelium ◽  
Cytotoxic Effects ◽  
Buccal Epithelial Cells ◽  
Toxicity In Vitro ◽  
Toxic Reactions ◽  
Light Microscopical Examination

The aim of the present study was to compare the toxicity in vitro with the toxicity in vivo of two commercial chemicals marketed for use in the oral cavity (GLUMA BondR and 3M Etching LiquidR). Confluent cultures of human buccal epithelial cells were exposed to graded concentrations of GLUMA Bond or 3M Etching Liquid for 5 minutes. The cytotoxic effects induced by this treatment were observed (cytomorphology, proliferation rate). In vivo, monkey buccal epithelium was exposed to GLUMA Bond or 3M Etching Liquid for 5 minutes. Biopsies were taken after 24 hours, and the buccal epithelium processed for light microscopical examination. In both models, the toxic reactions to GLUMA Bond were far more extensive than those caused by 3M Etching Liquid.

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