Abstract: For molars that need to be extracted due to severe periodontitis or periodontal-endodontic combined lesions, the bone wall of the extraction socket is often seriously damaged. After natural healing, there will be problems such as insufficiency of soft and hard tissues at the implant site, which will make the implant placement more difficult. Minimally invasive tooth extraction and ridge preservation can achieve a certain degree of bone augmentation and maintain soft tissue contour, thus create good soft and hard tissue conditions for implant therapy. However, for mandibular molar sites with complete loss of buccal and lingual bone wall, the technical difficulty of ridge preservation increases. This article illustrates a case of ridge preservation in mandibular molars with severe bone defect to facilitate implant treatment and demonstrates the clinical management to achieve predictable clinical outcome.

Key words: Minimally invasive extraction, Extraction site preservation, Mandibular molars, Dental implantation