The natural tooth crown is the upper part of the tooth that protrudes from the gum. It is covered with enamel and makes up the visible part of the tooth. In order to maintain tooth function, when it is destroyed, the natural tooth crown must be replaced with an artificial tooth crown.
What is the dental crown?
When people talk about dental crown, they immediately think about artificial crowning of the tooth. However, every tooth also has a natural dental crown. A tooth consists of a tooth root, the tooth neck and the tooth crown. The natural crown is connected to the neck of the tooth and protrudes from the gum. It is surrounded by enamel. The enamel gives the tooth the hardness needed to grind food. When the natural tooth crown is destroyed by caries bacteria, it can be replaced by an artificial crown. The name dental crown comes from the fact that the human molar looks similar to a royal crown when viewed from above.
Anatomy and structure
The natural tooth crown consists of dentin (tooth bone), which surrounds the pulp (tooth pulp), and enamel, which serves as protection for the dentin. The dentin is composed of approximately 65 percent calcium hydroxyapatite, 25 percent connective tissue-like material and 10 percent water. The dental pulp is embedded in the dentin. The pulp consists of nerve fibers and blood vessels that supply the tooth with nutrients and regulate its sensitivity. The enamel surrounding dentin is the hardest substance found anywhere in the body. It is made up of 95 percent calcium hydroxyapatite, some connective tissue and water. Thus, it has the hardness necessary to chew food. However, tooth enamel is sensitive to acid and slowly dissolves at a permanently low pH. This is due to acid-forming bacteria (caries bacteria, streptococci), which form acids as they decompose food residues that have not been removed. If this destroys the natural tooth crown, it must be replaced by an artificial one. The artificial dental crown can be made of full ceramic, gold alloy or gold sleeve for veneering ceramic or plastic. It is built either on the existing tooth stump or around a post fixed in the tooth root. Metal alloy dental crowns are most often used for the molars, which are not visible to the outside. An all-ceramic crown is indistinguishable in appearance from a natural dental crown and is therefore often used for the front teeth.
Function and tasks
Both natural and artificial dental crowns are responsible for the actual function of the tooth. They are used to chew and grind the ingested food. Under the grinding movements and mixing with saliva, the food pulp is prepared for the swallowing process, which allows it to pass through the esophagus into the stomach. Since teeth must last almost the entire life, the natural tooth crown is made of a very resistant material (the enamel) that surrounds the dentine. The enamel is very hard and resistant to ensure the chewing process without restrictions. However, in the course of time, the enamel slowly degrades due to the influence of acid-forming bacteria. However, this process can be significantly delayed by intensive tooth cleaning. In earlier human cultures, the loss of teeth also often led to death because food could no longer be prepared. Today there is the possibility of tooth replacement. In addition to complete dentures, dental crowns made of various materials can be built on the existing remaining tooth. Although the remaining teeth can completely take over the grinding function, it is however advisable to crown the destroyed teeth in order to stop the degradation process in the dental apparatus. In this way, the remaining teeth can be kept alive even longer. Resistant materials that can withstand even acids are also used for the artificial dental crowns. Depending on the application, they are made of precious gold alloys, gold veneers or full ceramics.
Diseases
The natural tooth crown is constantly exposed to attacks from acid-forming bacteria. Even with daily tooth cleaning and immediate removal of food residues on the teeth, the destructive work of caries bacteria (certain types of streptococci) cannot be stopped. It is only delayed.The decomposition of food residues that are particularly rich in carbohydrates produces acidic decomposition products that attack even the hard material of the tooth enamel. Initially, small holes form in the enamel, but they continue to enlarge. One day they reach the dentin and further the pulp. At the latest then there is a severe toothache, because the nerves are directly inflamed. The tooth can be preserved for a long time by killing the bacteria with antibiotics and closing the holes. However, when a degree of destruction is reached that inevitably causes the tooth to die, the tooth body can still continue to be built up with an artificial dental crown. It is true that the materials used are very resistant and acid-proof. Nevertheless, it is possible that the pathological destruction process will continue. Normally, the progressive degradation process should have stopped. Due to errors in the construction of the artificial dental crown or lack of dental hygiene, the inflammation under the crown can continue. This is the case if either the bacteria have not been completely removed or if the distance between the crown and the remaining tooth is too large. In this case, bacteria can always get under the crown and completely destroy the tooth including the root.