Questions related to Enamel
Like carbon isotope from fossil tooth enamel, is oxygen isotope also have some specific values to define humid or arid areas?
I would like to know why mostly of dentists doesn't use an adhesive system to their sealants, because when asked they just answer with "because that’s not the protocol" but in fact they’re plenty of studies like by Feigal in the late 2000 reporting the elasticity of the bonding agents serving as a long-term stress-breaker for these sealants. Moreover McCafferty & O’Connell reported the statistical significant improvement in the retention of a bonded sealant at 12 months over conventional sealants, and there's at least 10 more studies showing the benefits of bonding sealants. Is it time to switch the paradigm about bonding our sealants?
In 1834, Charles Wheatstone measured the velocity of electricity along two long wires, whereby he found a velocity of about 463,500 km/s, over 1.5 times the speed of light. In 1905, Nikola Tesla also measured a propagation speed for the telluric currents he transmitted trough the earth's surface of 471,240 km/s, remarkably close to Wheatsone's result and within 0.1% of pi/2 times the speed of light.
In order to validate the possibility of transmitting superluminal signals along a wire, we setup an experiment, similar in design to Wheatstone's, consisting of two relatively long wires which were excited by a capacitive discharge. Hereby, a mercury wetted relay was used as a switching element in order to obtain as fast a signal rise time as possible.
Quite surprisingly, the superluminal signal was detected and found to propagate at more than 1.8 times the speed of light. This is quite a lot faster than the theoretical pi/2 (1.57), which may be caused by the use of enamelled wire rather than unshielded wire.
I still need to work things further out, but you can take a look at the scope shots and setup to draw your own conclusions:
Besides this experiment, I've also worked on a new aether theory, whereby the electromagnetic domain is fully integrated with the fluid dynamics domain and whereby all units of measurement are expressed in just three fundamental ones: mass, length and time, which would explain the existence of superluminal longitudinal "sound" waves in the aether:
In this work, there are 18 references to papers wherein superluminal signals were detected with various methods, such as microwave experiments as well as experiments with optical fibers.
So, the question is: is this actual additional evidence of the existence of Tesla's superluminal longitudinal waves, or did I measure an artifact?
Update: The measurement presented above (even though preliminary), together with the 18 references around detection of superluminal signals in my paper as well as the recent work of Steffen Kühn leave little doubt that the actual propagation speed of the electric field is superluminal rather than that it propagates at c:
So, now we have two independent measurements of superluminal signal transmission along a transmission line. He has also pointed to the exact same problem in Maxwell's equations via a different path:
Taking all of this together, there simply is no escape to the conclusion that Maxwell's equations are indeed wrong. One cannot get away with violating the fundamental theorem of vector calculus, which is undoubtedly called fundamental for a reason, and it seems to me that after 120+ years of attempting to correct this obvious flaw by extending the model, i.e. make it "complete" by trying to find additional equations (including multi-dimensional ones), maybe it's time to try something else, like simply fixing the actual problem and revise Maxwell's equations.
Working on my master thesis, I've created and eroded 1 sample (Vertex exterior with enamel sample on the middle) and now need to measure the volume difference between before and after erosion? Any tutorial I can follow please?
1. if a person had an orthodontic treatment, would one could understand it, after the treathment? if Yes, what are the implications or traces to say so? Another question is, by looking an individual's cephalometric radiograph or bitewing , panoramic etc. Can one understand this?
2. Are those materials (archwire, ligature, springs etc.) used for orthodontic treatment leave behind a trace or any deformation on tooth enamel?
3. can we understand this macroscopicly? And, after the orthodontic treatment, does it occur a shift in size and morphology of teeth that has been to this treatment?
I am looking for articles for anisotropic mechanical properties of jawbones (maxilla and mandible).
I am looking for mechanical properties (modulus of elasticity, poisson ratio, compressive strength, shear modulus, density) of various sites of jawbones ( for maxilla- palate, premaxilla, pterygoid maxilla, zigomatic maxi and for mandible- symphisis, body, ramus and condylar areas.
also I am looking for same mechanical properties for enamel, dentine, pulp, pdl, and cementum.
please anyone having articles related send it to me.
I would be grateful
Thanks and regards
When we are evaluating the remineralization in the interface layer between the sealant and enamel using scanning electron microscopy (SEM)could we assess in the same time the mineral content in a quantitative way of the interface enamel?
Is there a fluoride home application compliance test, that would tell the use of fluoride in past week or month? Something similar to the glycated hemoglobin test that tells you your average level of blood sugar over the past 2 to 3 months.
We are evaluating telephone interventions to increase fluoride compliance for post -radiation caries patients. We would like to use something more objective than just self reported yes or no.
There is an old and semi-invasive method, but has not been used much in recent research:
van der Merwe, E. H., Retief, D. H., Barbakow, F. H., & Friedman, M. (1974). An evaluation of an in vivo enamel acid etch biopsy technique for fluoride determination. The Journal of the Dental Association of South Africa = Die Tydskrif van Die Tandheelkundige Vereniging van Suid-Afrika, 29(2), 81–87.
Brudevold, F., Reda, A., Aasenden, R., & Bakhos, Y. (1975). Determination of trace elements in surface enamel of human teeth by a new biopsy procedure. Archives of Oral Biology, 20(10), 667–673. https://doi.org/10.1016/0003-9969(75)90135-1
I am studying inhibitors effect on LDH activity in Streptococcus mutans and I want to study enamel Demineralization Test in vitro, is there any test to study enamel Demineralization in vitro??
I am working on lead-free glass enamels and I would like to know if anyone has any idea about what materials can help the glass enamels to become hide?
Thanks in advance
Is it possible for a dentist to use a product that highlights enamel or dentin ? It should have a real interest in the bonding procedures to apply. Of course it should not color the tissues or it should be removed very easily. Thank you for your help.
I want to know if interstitial fluid is also acidic in dental caries patients . which when flow in dentinal lymph and along rod sheath and cause demineralization.
Hi I am preparing enamel paint from alkyd of medium oil length. I found that the first coat of paint is getting tack free in 7-8 hours whereas the second coat is tack free in 5-6 hours. Can anyone explain this phenomenon of fast drying of second coat over the first one.
I need to perform AFM analysis on the labial surfaces of human teeth to evaluate enamel erosion. The reference articles suggest wet polishing to produce flat enamel surfaces. I need to know if this is mandatory. If yes, will it not change the original surface morphology of the tooth, thereby giving a wrong measurement on AFM?
In some paper, I found AmeloD as an inner enamel epithelial marker but pig AmeloD primer sequences is not available at NCBI. So i need to look for some other possible markers.
Please suggest me any Non toxic material for tooth enamel products.
want make make product for tooth which look like nail lacquer.
mainly fast drying material and which can make film on tooth easily.
I'm still confuse about the etching pattern on enamel based on the type of etching acid that been used and so on about the width of the pores that created by it? still confuse too about identifying which one is the tail nor enamel rod. can anyone suggest me a journal nor a book that worth to read to help me to understand about this? thank you so much for your help! its mean a lot to me. have a good day everyone!
Is there any clinical or in vitro evidence to suggesta benefit from restoring the full buccal surface of abfracted teeth with an indirect restoration?
In other words, if a tooth needs cuspal coverage for structural reasons, and there is a buccal abfraction, is there any reason to prepare the buccal surface other than esthetics? Could the effect of bonding the cervical area to the occlusal possibly outweigh the loss of stiffness related to removing the buccal enamel?
I have been on the hunt for an article or just some general advice about FT-IR spectra for human tooth enamel, particularly what is considered an "acceptable" range for C.I. values? I know there is some debate in the literature if C.I. values actually tell us anything about the diagenetic processes of human bone/tooth enamel, but I would like to get some opinions from other researchers about how they interpret sample spectra in their own projects.
Tooth enamel plays a critcal role in the function of teeth by providing a hard surfavce layer for wear and sometimes impact resistance. But it is a hard and brittle material that one would presume would readily crack. Although the DEJ provides an effective barrier for cracks in the enamel from reaching the dentin, thereby causing the whole tooth to fracture, are there mechanisms for the enamel to heal its cracks?
Discoloration of demineralized or cavitated surface of tooth is a major drawback of SDF (Silver Diamine Fluoride). This agent permanently blackens carious enamel and dentinal lesions.
Since, it is not mandatory to excavate the infected dentin before SDF application,and there is no tooth preparation also how would the longevity and aesthetics of such restorations be?
Any studies reporting the same?
I am working on my M.Sc. thesis about silver enameling. I have done some research in enameling on metal field, But unfortunately, I couldn't find any paper having to do with my thesis. Silver enameling is categorized in metal enameling. based on my research, the paper titled "Electrical Insulating Properties of Porcelain Enamels on Clopper " is the only reference which is close to my study.
F.Y.I.: you can find the mentioned paper by
This molar was assigned to M. primigenius, but looks very unusual.
First of all, the structure of the enamel is very unusual: very many tiny plates, and very parallel.
Besides the enamel structure, another issue is represented by the type of fang is presented in the images.
How could you describe this tooth ?
Could this molar be assigend wrong to M. primigenius ? What is the right identification ?
I would like to know if it's possible to prepare this surfaces by the most minimally invasive technique, so I have been thinking in air abrasion.
Do you think that the amount of tissue removed would be minus with air abrasion? Or it would be less with a fine-grained (polishing) high-speed burr?
Also it is important to find out if air abrasion is able to remove all the demineralized layer (0.2 y 3 µm). The dephts of the demineralized layer are described by Amaechi and Higham, 2001; Eisenburger et al., 2001; Wiegand et al., 2007; Cheng et al., 2009; Voronets and Lussi, 2009.
Which laboratory methods can be used to compare abrasive effect of toothpaste formulations on teeth (enamel and dentin)
From available studies Relative dentin abrasivity index for common abrasives is available. But I have not found any laboratory in India which carry out Relative dentin abrasivity tests.
Is there any alternative testing method which can be used to determine erosive effect or the abrasiveness of toothpaste formulation on teeth.
If possible please suggests laboratories in India that could be helpful in carrying out these tests. (possibly with no conflict of interests)
I'm curious if anyone has looked at the difference in enamel band thickness between the upper and lower teeth of any mammal, but more specifically ungulates.
Caries has conventionally been treated with drlling and fillling keeping GV Black's rule of extension for prevention in mind. Contemporarily, caries is recommended to be treated with minimal intervention (MID) keeping prevention of extension in mind.In near future, caries will be treated without drill or any other method which involves loss of tooth structure as protien has been synthesized which replaces enamel. I will appreciate if someone elaborate on it in this forum.
Is there any material or information onto what exactly is the mechanism of fluoride on developing enamel and timing at which this exposure should occur for fluorosis to develop.
Does bleaching, especially home bleaching either with Carbamyl or Hydrogen Peroxide cause calcium loss or degradation in tooth enamel?
There is some debate about whether to bevel or not the cavosurface margins in the occlusal box of a class II preparation for resin restoration in a primary molar in order to remove the aprismatic enamel and increase the surface area for bonding.
I am searching for a high-temperature resistant enamel or glassceramic to coat a stainless steel. It should be stable until 1000°C. The thermal expansion coefficient should be between 130-180 * 10-7 K-1. If anybody has an idea, please help me.
I was following a discussion on how lower pH (acidification) causes demineralization of tooth enamel, increasing risk for caries. This ties together with Bardow, A. et al (2000) - Archives of Oral Biology, where they found that an unstimulated low salivary flow rate was the best variable for predicting demineralization (bicarbonate, calcium, phosphate).
Therefore, low pH and low salivary flow -> demineralization -> leading to increased caries risk.
So what is causing the change in pH and the change in salivary flow?
I have been looking if stress, critical illness, hospitalization may affect the salivary pH. And in turn, this would increase the bacterial colonization and microorganisms that could lead to a hospital acquired aspiration pneumonia. There is a lot of info out there on oral flora changing in critically ill and oral flora associated with ventilator acquired pneumonia, but I want to know more about how and when the pH is affected. Is a change in pH the first causal factor that gets the ball rolling?
In the recent past agents like cpp-app , bio active glass, xylitol and other agents have shown to effectively counter initial carious lesions in tooth enamel, there have been many invitro studies supporting the same, though long term animal or invivo studies are required , never the less these agents have shown promising results to replace fluorides as the major agent for countering tooth caries.