▎ 摘　　要

NOVELTY - Treating bone defect or injury or reconstructing new bone involves using handheld three-dimensional (3D) printer to directly deposit filament or printing material into bone defect of subject, where the filament or printing material comprises polymer having a melting point of 70degrees Celsius or lower. USE - Method for treating bone defect or injury or reconstructing new bone for use in cosmetic or non-cosmetic purpose in subject need treating is performed as a portion of neurosurgical craniotomy, a cranio-maxillofacial (CMF) surgery reconstruction, reconstruction of extremities such as a hand or other extremity surgery, an adult or pediatric orthopedic surgery, treatment of a facial fracture, or a spinal surgery (claimed). ADVANTAGE - The treated bone defect or injury or reconstructing new bone has heat flowable, absorbable, biodegradable material with no drilling or screw type hardware for bone flap fixation of craniotomy, and can easily be extended for the delivery of biological materials, such as cell, growth factor, and autograft into bone defect. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: 1. a filament or printing material for 3D printing, which compises: polycaprolactone (PCL), zinc oxide particle, and hydroxyapatite particle; 2. a scaffold, which comprises: a filament or printing material and cell deposited on or in the filament or printing material; 3. a method of fixing, adhering, or gluing a bone fracture, a bone flap, a bone graft and/or pieces of bone in a subject, which involves: using a handheld 3D printer to directly deposit a filament or printing material inside, over and/or around the bone fracture, bone flap, or bone graft and/or at an interface of a flap and a bone within the subject, where the filament or printing material comprises a polymer having a melting point of 70degrees Celsius or lower; and 4. a method for retaining a bone graft and/or a bone graft substitute in a bone defect of a subject in need, which involves: using a handheld 3D printer to directly deposit a filament or printing material into the bone defect of the subject, where the filament or printing material is deposited so as to print a graft cage in the defect, the graft cage is sized to retain the bone graft and/or bone graft substitute in a specific location in the defect, and allowing subject to heal while bone graft and/or bone graft substitute is retained at desired location using the graft cage.