The purpose of this study is to evaluate an ability of a moldable autogenous tooth bone graft material (M-AutoBT), which is made of demineralized dentin matrix (DDM) and hydroxypropylmethyl cellulose (HPMC) to repair sinus-related defects in the implant dentistry. Sinus-related alveolar defects were classified into three types depending on the remnant of socket wall as follows; Class I: Only alveolar bone repair is required even if sinus cavity is involved (remained socket wall > 5mm). Class II: Both alveolar bone and sinus repair are required (3mm < remained socket wall < 5mm). Class III: Only sinus repair is required without any alveolar bone (remained socket wall < 3mm). Sinus cavity should always be involved during the implant placement regardless of defect types. The histological examination of three case reports, which represented class I, II and III defect respectively, showed osteoconductive and osteoinductive functions of M-AutoBT that is similar to the effect of the conventional AutoBT. Therefore, HPMC might be the suitable base material for AutoBT.