Evaluation of the Prevalence Rate and Related Risk Factors of Ridge Preservation

Treated by dental implant is a well document and popular therapy nowadays. Placement of a dental implant in an ideal three-dimensional position is critical in achieving a predictable long-term success. However, healing of an extraction socket involves bone remodeling, which inevitably leads to atrophic changes of the alveolar ridge. Studies have shown that most of the resorption occurs during the first 3 months of healing, although dimensional changes can be observed up to 1 year after tooth extraction, resulting in approximately 50% reduction of the bucco-lingual dimension of the alveolar ridge, mainly due to the resorption of the bundle bone plate. Therefore, the timing of implant placement in extraction sockets can influence the surgery operability and treatment period of time. The classifications of timing of implant placement in extraction sockets as following: Type I: immediate implant placement: implant placement immediately following tooth extraction and as part of the same surgical procedure. Type II: early implant placement: surgery after complete soft tissue coverage of the socket (typically 4\~8 weeks). Type III: early implant placement: implant surgery after substantial clinical and/or radiographic bone fill of the socket (typically 12\~16 weeks). Type IV: late implant placement: surgery at healed site (typically more than 16 weeks). Considering of technique sensitivity and treatment time consuming, early implant placement is the most acceptable clinically. Many techniques have been developed to maintain the architecture of residual alveolar ridges and regenerative techniques for socket preservation is one of them. This procedure has been widely tested in controlled and uncontrolled studies with various materials and clinical approaches. However, this procedure may require longer treatment period compare to conventional or early implant placement protocol. Meanwhile, there is no study revealed how often and when does socket preservation need to preve