The objective of this study was to histologically and immunologically analyze the level of bone substitution and the presence of new blood vessels in a nanobiomaterial composed of hydroxyapatite and BTCP in a maxillary sinus lift surgery. A case of a maxillary sinus lift was investigated. The patient had a 1.0 mm bone remnant on the left side and 2 grams of nanobiomaterial (80% hydroxyapatite and 20% β-tricalcium phosphate) were grafted into the pneumatized sinus. After 6 months, during dental implant placement surgery, grafted bone samples were collected with 4 mm trephines.