Osseointegrated root form implants have been applied successfully in treating fully and partially edentulous patients and patients with single tooth missing. However, the success rate of osseointegrated dental implants was not as good in patients with poor bone quality. The reasons are believed that poor bone quality reduces the initial stability of dental implants and then reduces the success rate. For increasing initial stability of dental implants, some technical modifications are suggested in literature. However, due to lack of an objective method to evaluate bone quality, they are controversial. The purposes of this clinical study are to develop a standard procedure which using cutting resistance measured by Osseocare in surgery to evaluate the bone quality and to compare with the clinical experiences of oral surgeons. The objective outcome, initial stability of dental implant, is measured with Osstell. The analyzed results are also helpful for less experienced surgeons.

Materials & Methods:

1. Patient eligibility: Six implant surgeons will assist the experiment. The subjects are patient who will receive dental implant treatment in Dental department of NTUH. Sixty subjects are offered by six surgeons. They must fully fill the requirements as following

Inclusion Criteria:

• No major systemic diseases
• Mouth opening: > 35 mm
• Missing teeth at anterior or premolar area and willing to restored by implantation

Exclusion Criteria:

• Uncomfortable or other condition occurring in the surgical procedure make the measuring unacceptable