The Chairside Instructor 48 An impaction is when a tooth is unable to erupt into the mouth because the tooth is blocked by another tooth or by bone or gum tissue. Bony Impaction — part or all of the tooth is covered by bone Tissue Impaction — biting surface of the tooth is covered by soft tissue (gums) Extraction of Impacted Tooth Different Types of Impactions Impacted third molar After the molar is extracted, the site is sutured closed. Over time, new bone will grow in and fill the site. Inflamed area Wisdom Teeth Other Oral Conditions