#2 What I Learned Today

Biochemistry

Did an introduction lecture into carbohydrates, specifically the differing forms (D- versus L-isomers). Will post more on this later when I get some clarification on some of the work.

Principles of Dental Materials

We spent most of the class talking about electectrical properties, classes of solids, and internal structures of materials.

Two major electrical properties experienced in dental materials include galvanism and electrochemical corrosion. This can occur due to the fact that you can have metals (amalgam, gold) coming into contact with dissimilar metals (see prior), and electrolytes through saliva, salt water, etc. This allows for currents to be generated, which can cause pain and corrosion.

Solid materials is broken down into three different categories: metals, nonmetals and polymers. Typical metals include steel, aluminum, brass, titanium, gold and silver. They have metalliac lusters, are opaque, have thermal and chemical conductivities, and tend to be strong, ductile, tough and stiff. Ceramics are compounds of metals and nonmetals, with common examples being porcelain, glass, concrete and abraisives. They tend to be translucent, non-conductive, and are hard, brittle and stiff. Polymers are organic-based compounds, such as plastics, rubbers and waxes. They tend to be transparent or opaque, and are soft, weak, flexible and lightweight.

Chemical bonding in compounds occurs by covalent bonding, metallic bonding, ionic bonding, and Van Der Waals bonding (in order from highest to lowest bond strength).

Finally, we started into studying the nanostructure, microstructure and macrostructure of materials. Nanostructures form lattices, with the lattice being made up of repeated unit cells (types include cuboidal, face-centered, body-centered and hexgonal close packed). Materials are often defined and identified by compostion and structure. This can be determined in relation to temperature through the use of phase diagrams (google for an example image).

Dental Anatomy

The focus of today's lecture was the mandibular central and lateral incisors. We looked at them from all aspects, including the labial, lingual, mesial, distal and incisal surfaces.

Mandibular Centrals

From the labial view, you typically find that the lateral incisors are slightly bigger mesiodistally than the central incisors (note, this is flipped from the maxillary). The both the mesioincisal and distoincisal line angles are very sharp (almost 90 degrees) with very straight surfaces running to the cervical.

From the mesial and distal view, both sides have height of contours in the incisal third of the tooth. The cemento-enamel junction on the distal side tends to curve much more gradually to the incisal than the mesial.

From the lingual view, you typically find not very distinct features (mesial and distal ridges, fossa). The cingulum is slightly angled to the distal.

The root is obviously single, and you may find fossa on the distal (I think?).

Mandibular Laterals

Obviously, very similar to the Centrals with some few exceptions. One, the distoincisal angle is more rounded, and the incisal edge itself is twisted towards the distolingual. Also, the height of contour on the distal of the lateral drops towards the cervical a little more (though it's still considered to be in the incisal third) and is larger.

Thanks for reading.