The indications are very important. However, there are individual differences in patients and doctors' grasp of indications, and there are no absolute boundaries. There are optimal indications, as well as reserved conditional indications, non-indications or contraindications. Doctors should consider in the long run, grasp the scale of the indications, and this scale measures the level of medical technology and knowledge of doctors, and even measure the level of professional ethics of doctors, it should be noted that doctors such as overly relaxed indications, will bring damage and suffering to the patient. This is a rare passage in the years of boring textbooks, but also for the proliferation of porcelain crowns to expand the indications of the status quo of a helpless and pitiful. Therefore, the first step in the production of porcelain crowns is to strictly eliminate contraindications (the previous word is wrong, the word is right) contraindications: the patient's age, clinical crowns are short, the pulp angle is high, large, apical part of the root has not been fully formed
Missing more teeth, the remaining teeth can not withstand the fixed prosthesis jaw force
Missing teeth adjacent to the pulp has been a pathology untreated
Missing teeth adjacent to the teeth have When periodontitis is untreated
The distance from the mucous membrane at the top of the alveolar ridge of the missing tooth to the surface of the opposite jaw is too small.
As can be seen from the above, the teaching has been very despondent, very broadly defined contraindications, these five conditions above, almost all of which can be transformed. Already the contraindications have been expanded much more than in previous years' editions. This is the first step of the porcelain crowns ---- can you do.
The second step: design, to be considered is function, shape, chewing interference, pronunciation. Conditional should first take the model to do preoperative model analysis, to the point of using cosmetic wax on the model to do the expected postoperative recovery. This step is the expected postoperative look, almost like redoing a dress paper pattern. If this step exists, the charge for porcelain crowns should be more than $1,000 each even for nickel-chrome porcelain crowns. Just because many patients can not read the model on the postoperative, spend too much time, generally be erased.
The third step: the patient agrees to prepare, start the nurse to prepare the table, take preoperative photos, anesthesia.
Step 4: This is a more critical step, preparation. Doctors at this time to have a prepared teeth in mind after the form, and strictly in accordance with this projected to sculpt the shape of the abutment. This is to incorporate the gingival process. This is still not used in many places, but it is a necessary step. It is a necessary process to protect the gums from being injured during the preparation process and to more accurately transfer the marginal boundaries of the porcelain crown to the technician.
Step 5: modeling, which seems to be nothing to write home about, is the faithful transfer of the prepared form of the abutment into a plaster model. What is needed is stability, quickness and proper strength. A good quality silicone gel will retain the model negative for 48 hours without the need to instill a positive mold. This saves the nurse time in filling the model. One less step. This one-step savings is more revolutionary.
Step 6:The doctor fills out the design sheet, medical records, and calls the technician's office to come pick up the model.
Step 7: The following are the steps of the processing plant, because they are all assembly line standardized systematic production, we report like a running account. Fill the model, box saw abutment teeth, coated with a separator, do wax-up, take wax-up, stick casting channel, embedding, Maofu furnace baking wax, casting, sand drop, electrolysis, sandblasting, model try on the inner crown, into the porcelain crown oxidation, on the shade layer, the body layer, cut end layer, car porcelain (grinding out the shape of the tooth), model jaw adjustment, go to the casting channel, on the glaze. Of course, in the case of all-porcelain crowns, or CAD crowns, the process is different. But definitely not less than the above steps. Delivery business sent back to the clinic.
Step 8: clinical first wear, strictly speaking, there should be a temporary adhesive material, so that the patient to try on, try to wear satisfactory if there is no need to adjust the jaw, can be directly dry, EDTA to remove the tarnish layer, moisture barrier, adhesive. If it is adjusted, it should theoretically be sent back to the laboratory for glazing. The doctor should also advise the patient on the appropriate precautions to be taken in his/her case. The total number of steps in this way is roughly equal to at least 50. Whether it is an all-ceramic crown or a metal crown, it is not so much the material but the labor, the brain power, the endurance that is involved. It is a fact that dentists understand perfectly well that the procedure for preparing a nickel-chromium crown and a zirconium oxide crown is the same, and the thicknesses are almost the same, but the profit margins in the middle of the process are just as high as the sky. Medicine in the temporary space, is temporarily inseparable. So there is a nickel-chromium crown 400, cobalt-chromium crown 800, silver-palladium crown 1800. zirconia crown 3000 difference.