Do you know how dentists design your teeth?

For dentists, washing teeth, filling teeth and extracting wisdom teeth are not problems. Real top dentists are trying to design millimeter-level teeth to make a rotten tooth look brand-new.

The progress of the dental industry is largely driven by the entertainment industry. In order to improve the image of actors at all costs, Los Angeles, where Hollywood is located, has become the most developed dental area in the world.

But in China, the mainstream solution to bad teeth is crown-wear metal or ceramic braces after grinding teeth. Besides ugliness and durability, the irreversible wear of worn teeth will cause more problems in the future.

The job of top dentists is to constantly challenge these two aspects-optimizing appearance and reducing wear.

A common solution is called digital smile design, or DSD for short, which is called digital smile design in Chinese.

DSD was first developed and realized by Brazilian dental expert Christian Coachman. Through the digitalization of oral model, pre-tooth design, veneer making and fine tooth preparation, the aesthetic restoration of teeth can be accurately realized on the order of millimeters.

The first step of digitalization is accurate oral photography.

Through 13 chair photos, 13 studio photos and two videos, dentists can analyze the convexity, texture, color band, occlusal relationship of patients' teeth and the relationship between teeth, gums and lips.

These conclusions will support their digital design in keynote.

We found Dr. Yang Chen, the head of the digital dental center of Gade. The following is Dr. Chen's demonstration:

The first thing to determine is the smile line, which is the ideal position of the teeth when the patient smiles. According to the relationship between teeth and laugh lines, we can design every tooth that needs to be restored.

First determine the length of the central incisor, and then determine the width of the central incisor according to the proportion. The ideal ratio is 75%-85% of the length.

After determining the length and width of the central incisor, the golden scale is usually used to determine the width of other teeth. That is, when the width of lateral incisors is 1, the central incisors with the width of 1.6 18 and the canines with the width of 0.6 18 are considered as the most standard tooth ratio.

Of course, dentists will also make adjustments according to patients' own characteristics. For example, Asians tend to want smaller central incisors than Europeans and Americans.

After that, you can use electronic vernier caliper to measure the tooth data, and calibrate the ruler in keynote to measure the tooth value that needs to be repaired.

These images and parameters will help dentists to make porcelain veneers accurately.

The first step in making veneers is to obtain the customer's tooth model. The common impression material is silica gel, and the abutment model can be obtained by pouring gypsum into the silica gel impression. Cutting the abutment model to make the impression, then casting the impression with refractory materials and sintering to obtain working models of different materials.

Covering the surface of the working model with porcelain powder, and then sintering the porcelain powder layer to form a porcelain tooth veneer.

The key to veneer is thinness.

At present, the thickness of veneer can be controlled at about 0.5 mm, and the thinner the veneer attached to the teeth, the less the wear on the teeth. In addition, the color, luster and texture of veneer also need to be fine-tuned to get close to the real texture.

The standardization of porcelain veneers is low, which requires high personal skills of technicians. In China, the veneering needs of most stomatological hospitals can only be outsourced to factories, and only a few private hospitals can afford full-time technicians.

The edge of porcelain veneer is often only a few tenths of a millimeter. In order to make these tenths of a millimeter fit the teeth perfectly, the dentist needs to complete extremely fine tooth preparation.

Lycra oral microscope, which can be magnified 40 times, can help dentists realize this millimeter-scale micro-sculpture and complete the last step of aesthetic restoration.

DSD scheme doesn't sound too difficult, but in practice, the accuracy of any link, such as photography position, image alignment, calibration, veneering, tooth preparation and bonding, will lead to bad results.

This is why the DSD program can only be implemented in private hospitals in big cities in China.

If every link has an error of several thousandths, the final error may be several percent. If every link is compromised by a few tenths of a millimeter, the final compromise may be a few millimeters.

The job of top dentists is to accurately control this natural occurrence.