The aim of this study was to investigate the therapeutic effect of sloped dental implants. It can reduce the need of osteoectomy, reduce discomfort of procedures, and is easier for maintenance.

20 OsseoSpeed ™ Profile EV and 20 OsseoSpeed ™ EV groups will be randomly implanted into the oblique edentulous ridges of subjects, and the treatment response will be monitored for 3 years. The implantation area will be randomly divided into two groups, One group was treated with OsseoSpeed ™ Profile EV (sloped group) and the other group was treated with OsseoSpeed ™ EV (control group). The same patient had the same implant as the same quadrant.

The patient will be followed up regularly for follow-up, followed by clinical attachment level, probing depth, bleeding on probing, keratinized gingival width (Keratinized gingiva), mobility (mobility) and other clinical indicators of the measurement, regular dental radiography, gingival crevicular fluid (GCF) collection and bone integration measurement.

After six months of implantation, prosthesis will delivered and loaded functionally, and regular follow-up will be arranged. In each time of follow-up, examination will be carried out with regards to periodontal pocket depth, clinical attachment height, periodontal bleeding index, keratinized gingival width, and other clinical indicators of the measurement, at the end of the experiment, that is, after three years, and then a dental root film irradiation, GCF collection and osseointegration measurement.

20-80 years old with appropriate oral cleaning ability; the computer tomography shows > 1 mm buccolingual discrepancy of alveolar ridge height; no generalized periodontitis, or had history of periodontitis but has been completed treatment; no major systemic infection or major systemic illness; not taken antibiotics in the past two weeks Not pregnant or breastfeeding