The main purpose of the present study is to evaluate the dental implant placement using two different CBCT-derived templates and to study the related factors that affect accuracy so as to support the further clinical application of the technique. Thirty patients with partial edentulous denture are recruited. They are randomized to two groups. A radiographic guide is prepared before CT/CBCT scan. The CT/CBCT scan DICOM files are loaded in a planning program and converted into 3D computer images. A surgical template is fabricated through this virtual planning. After 6 weeks, if the implants are judged stable, the patient has the option of replacing the fixed prosthesis. Patients are recalled for oral hygiene maintenance and prosthetic controls every 6 months for the entire duration of the study.

Inclusion Criteria:

• Partial edentulism
• Missing more than three teeth in succession
• Presence of adjacent teeth
• Systemically healthy
• Good maxillomandibular relation
• Maximal mouth opening>5 mm

Exclusion Criteria:

• Poor oral hygiene
• Severe parafunctional habits, for example, bruxing and clenching
• Presence of clinically active periodontal disease as expressed by probing pocket depths≥4 mm in combination with bleeding on probing
• Maxillary sinus involvement
• Conditions that might lead to a possibly lowered regenerative capacity of the bone, for example, osteoporosis and Paget's disease
• Pregnant or expecting to be pregnant
• History of drug and alcohol abuse
• History of systemic diseases that would contraindicate oral surgical treatment, for example, uncontrolled diabetes (defined as HBA1c level >7%)
• Radiotherapy in the head and neck area
• On certain medications like bisphosphonates or steroids currently or within the past three months
• Unwillingness to return for the follow-up examination
• Smokers (more than20 cigarettes per day). Subjects smoking <20 cigarettes per day were requested to stop smoking before and after surgery