What is the biological range?

The biological space is defined as the soft tissue that adheres to the tooth root above the alveolar crest. The biological space acts as a protective barrier that prevents bacteria from entering important periodontal structures such as the alveolar bone and periodontal ligament. When the completion line of the porcelain tooth invades the biological space, it means that bacteria have moved closer to the alveolar crest and will cause persistent gingivitis.

Treatment guidelines for periodontitis caused by biological disturbances

If the smile line is low and the patient does not care about aesthetics, a periodontal flap surgery can be performed to clean the area and re-establish the biological space, adjusting the bone to match the position of the finishing line. Usually, the alveolar bone edge is about 3 mm from the finishing line. After surgery, the finishing line is often exposed, affecting aesthetics.

If the aesthetic requirement is to remove the dental bridge, lengthen the crown to change the position of the biological space. The commonly used method is tooth lengthening surgery (in addition, orthodontic treatment can be combined with or without surgery). After the tooth lengthening surgery, the patient should wear a temporary restoration with a completion line position suitable for the biological space for a minimum period of 3 months. Some opinions suggest waiting from 6 months to 1 year. In some urgent cases, the restoration can be done after 6 weeks, however, there may be changes in the gum line, causing the completion line to be exposed.