At which location in enamel is the density of enamel crystals is lowest

At which location in enamel is the density of enamel crystals is lowest:

a- Prismless enamel

b- DEJ***

c- Center of enamel Prisms

d- Edge of enamel Prisms

e- Facial enamel

Which is strongest enamel or dentine?

However, judging from the measured hardness values, enamel was considered harder than dentin. Therefore, enamel has higher wear resistance, making it suitable for grinding and crushing foods, and dentin has higher force resistance, making it suitable for absorbing bite forces.

Which is hardest dentine or enamel?

Enamel is the hardest substance of the human body and it is the outer layer of the crown. Dentine is a layer that lies beneath the enamel of the tooth.

What is the rule to find density?

The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre. For example, the density of water is 1 gram per cubic centimetre, and Earth's density is 5.51 grams per cubic centimetre.

What is the densest crystal structure?

There are two simple regular lattices that achieve this highest average density. They are called face-centered cubic (FCC) (also called cubic close packed) and hexagonal close-packed (HCP), based on their symmetry.

Which crystal structure has the highest packing density?

Hexagonal close-packed lattice has the highest packing efficiency of 74%. The packing efficiencies of simple cubic and body-centred cubic lattices are 52.4% and 68% respectively.

Which of the following affect the density of the crystal is affected?

Vacancy and Schottky defect which lead to decrease the density both are the types of a stoichiometric defect.

How is the density of the crystal affected by the defect?

Due to the Schottky defect, the density of the crystal is decreased. This is because ions (both cations and anions) are missing from the crystal.

In which of the following defect the density of the crystal is increased?

Interstitial defect, because in this defect a foreign atom/ions occupy interstitial positions. Hence the overall density of a solid increases.

Which point defect lowers the density of a crystal?

Schottky defect

Due to presence of vacant lattice sites in Schottky defect, there is a decrease in the density of crystal.

Which crystal has low density?

A muonium hydride molecule is a bound state of muonium and hydrogen atoms. It has half the mass of a parahydrogen molecule and very similar electronic properties in its ground state.

What are the zones of enamel caries?

Four zones were identified in the lesions, based on their optical appearance and degree of staining: pink, light pink, transparent, and apparently normal.

Which zone is not always present in enamel caries?

Zone 1: Translucent zone – Represent the advancing front of the lesion – Ten times more porous than sound enamel – Not always present. – Formed due to demineralization.

What area of the tooth is most vulnerable to decay?

Molars and premolars have numerous pits and fissures that are great for grinding food, but also attract bacteria and leftover food bits. It's difficult to brush every nook and cranny, so these teeth are the ones that most often develop cavities and other problems.

What is the difference between primary and secondary dentin?

The key difference between primary and secondary dentin is that primary dentin is a type of dentin formed before tooth eruption, while secondary dentin is a type of dentin formed after tooth eruption. Dentin is a hard, bony tissue that makes up the main structure of a tooth. It is a mineralized connective tissue.

Which is most to the least radiopaque enamel bone dentin?

Enamel, Dentin, Cementum and bone: Enamel: is the most radiopaque structure. Dentin: less radiopaque than enamel, has the same radiopacity as bone. in the mandible they are usually coarse and run in a horizontal pattern and larger bone trabecular spaces than in maxillary bone.

Which tooth structure is hardest most calcified )?

Enamel: The outer layer of a tooth is the enamel. Usually white or creamy ivory in color, enamel is the hardest layer of a tooth. Containing a mineral called hydroxyapatite that is related to calcium phosphate, the enamel is inorganic, meaning it's not a living substance.

Where is dentin found in the tooth?

Dentin. That part of the tooth that is beneath enamel and cementum. It contains microscopic tubules (small hollow tubes or canals). When dentin loses its protective covering (enamel), the tubules allow heat and cold or acidic or sticky foods to stimulate the nerves and cells inside the tooth, causing sensitivity.

Which layer has the least organic content in tooth?

The organic content of enamel is less than that of dentin. The organic content consist of some unique proteins present only in enamel and lipids [5]. The enamel is formed only once before the eruption of the tooth.

How is enamel thickness measured?

By measuring the time interval between the transmission of an ultrasound pulse on the enamel surface and the echo produced by the amelodentinal junction (ADJ), and using data on the mean longitudinal sound velocity in enamel, the thickness of the enamel layer can be calculated.