Here's the conclusion to Debbie Aliya's series on a tooth overlay procedure. Parts 1-3 can be found here.

In Figure 8, we can also see that there are some purple areas. That indicates that the silicon (pink) and oxygen (blue) are, in some cases, being found together. It could be silica (SiO₂), which may be a part of the ceramic being machined. Again, the EDS does not determine the presence of chemical compounds or crystal structures, only the type of atom. Using our other knowledge, we can speculate that it is silica (SiO₂). Likewise, the EDS method does not allow us to determine that the carbon-rich abrasive particles are diamond, only that they are almost entirely carbon. Again, using our other knowledge, we can speculate that it is diamond.

The blue areas are unlikely to be pure oxygen, which is a gas. SEMs operate in a partial or high (in my instrument’s case) vacuum. Therefore, it’s likely that the oxygen is present as an oxide but of an element whose overall concentration is so low that the mapping software did not detect it. Alternatively, I might have told the software to only include the four most concentrated elements in the display.

In any case, note how there are little patches of blue that are pressed into the green (suspected diamond) abrasive particle at the top of the image (just left of center). This may be residue from the ceramic blank that the burr was used to machine. Many common ceramics are oxides.

Closing Summary

My adventure at the dentist allowed me to have a lighthearted look at some specialty technology items from everyday life. We did not formally address the issue of failure versus damage. The tool wear apparently happened at the expected rate, so the burr did not fail; it simply wore out as the manufacturer predicted. I am 62 years old, so I really can’t complain that my tooth failed. My teeth are about the most robust and least demanding part of my physical being. I apparently chew my food preferentially using the right side of my jaw, and the enamel wore out.

The sharp edges of exposed enamel on the left side are limited to a small area, and the edges are not as sharp as the other side before the one tooth chipped and the other was rounded off a bit by the dentist. Looking at the machining and heat-treating processes used to make my new dental prosthetic gave us a chance to explore some industrial heating concepts (preheat to avoid thermal shock) and some lab tools (scanning electron microscope and EDS micro-chemical analysis).

Interpreting EDS data with the new instruments can be quite intuitive (element mapping), but it is also easy to misinterpret the data. I can’t tell you how many analysts think that the carbon peak in an EDS spectrum is calcium. It’s easy to confuse quite a number of atomic pairs because the peaks are so close to each other. As in any field of expertise, it requires knowledge and experience to understand what the data mean. Computers make it easier to get data, but the computer on its own can’t determine the quality of the data.

Here's the conclusion to Debbie Aliya's series on a tooth overlay procedure. Parts 1-3 can be found here.

In Figure 8, we can also see that there are some purple areas. That indicates that the silicon (pink) and oxygen (blue) are, in some cases, being found together. It could be silica (SiO₂), which may be a part of the ceramic being machined. Again, the EDS does not determine the presence of chemical compounds or crystal structures, only the type of atom. Using our other knowledge, we can speculate that it is silica (SiO₂). Likewise, the EDS method does not allow us to determine that the carbon-rich abrasive particles are diamond, only that they are almost entirely carbon. Again, using our other knowledge, we can speculate that it is diamond.

The blue areas are unlikely to be pure oxygen, which is a gas. SEMs operate in a partial or high (in my instrument’s case) vacuum. Therefore, it’s likely that the oxygen is present as an oxide but of an element whose overall concentration is so low that the mapping software did not detect it. Alternatively, I might have told the software to only include the four most concentrated elements in the display.

In any case, note how there are little patches of blue that are pressed into the green (suspected diamond) abrasive particle at the top of the image (just left of center). This may be residue from the ceramic blank that the burr was used to machine. Many common ceramics are oxides.

Closing Summary

My adventure at the dentist allowed me to have a lighthearted look at some specialty technology items from everyday life. We did not formally address the issue of failure versus damage. The tool wear apparently happened at the expected rate, so the burr did not fail; it simply wore out as the manufacturer predicted. I am 62 years old, so I really can’t complain that my tooth failed. My teeth are about the most robust and least demanding part of my physical being. I apparently chew my food preferentially using the right side of my jaw, and the enamel wore out.

The sharp edges of exposed enamel on the left side are limited to a small area, and the edges are not as sharp as the other side before the one tooth chipped and the other was rounded off a bit by the dentist. Looking at the machining and heat-treating processes used to make my new dental prosthetic gave us a chance to explore some industrial heating concepts (preheat to avoid thermal shock) and some lab tools (scanning electron microscope and EDS micro-chemical analysis).

Interpreting EDS data with the new instruments can be quite intuitive (element mapping), but it is also easy to misinterpret the data. I can’t tell you how many analysts think that the carbon peak in an EDS spectrum is calcium. It’s easy to confuse quite a number of atomic pairs because the peaks are so close to each other. As in any field of expertise, it requires knowledge and experience to understand what the data mean. Computers make it easier to get data, but the computer on its own can’t determine the quality of the data.