Transcrestal sinus floor augmentation applied for severely atrophic maxilla sinus floor augmentation is frequently performed because of posterior maxilla resorption and low bone density. The traditional perspective is that the residual bone height is a main factor influencing the selection of the augmentation technique and the transcrestal technique can only be used when the residual bone height is more than 4-5 mm. However, many researchers have used this technique with lower bone heights because of the development of better surgical instruments and clinical skills. Based on the review of the literature in recent years and the author′s understanding of clinical operation, this paper reviews the improvement progress and operation skills of the application of transalveolar ridge top maxillary sinus lift in the severely absorbed maxillary posterior tooth area.

Currently, computer-aided implant surgeries include implant placement surgery under the guidance of a dynamic navigation system. With the use of software inherent in the navigation system, doctors can make a preoperative plan including the ideal position of the implant. Then the plan can be accurately transferred to the surgery, during which the real-time condition of the drill and its relationship with the surgical region will be visualized by the surgeon and the drill can be adjusted in a timely manner. Currently the dynamic navigation system is increasingly widely utilized, especially in cases of esthetic zones or surgical sites with important anatomical structures. However, the clinical workflow of the navigation system is complicated, including CBCT taken after the registration device placement, prosthetic-driven 3D design, calibration, registration, navigated borehole preparation and implant placement surgery. Many details should be considered when the device is applied, including implant position design, fixation of the tracking device, registration, and stable borehole preparation under the guidance of dynamic navigation. Therefore, this article introduces the dynamic navigation system into the clinical workflow and evaluates, the effects of the application and the clinical features. The new progress of the navigation system in the field of implantology is demonstrated at the same time, including navigated surgery in fully edentulous arches and in the zygomatic zone. Further improvements in the navigation system in terms of the accuracy and simplification of the workflow are needed in the future.

Chronic periodontitis is a prevalent disease; if left untreated, it is a main indication for tooth extraction and can lead to tooth loss. The reactive soft tissue, formed as a result of the immune response to chronic inflammation, is left in the compromised socket. The major concern is how to deal with the residual reactive soft tissue. Conservative thought states that the reactive soft tissue should be completely debrided. In addition, novel practices concerning the reactive soft tissue were proposed in recent trials, which demonstrated that there might be merits for soft and hard tissue regeneration with preservation of the reactive soft tissue. Studies have shown that mesenchymal stem cells exist in inflammatory reactive soft tissue, stressing their potential in tissue regeneration. Although the therapeutic value is highly promising, the specific components of the reactive soft tissue and the standard on whether it should be preserved need further investigation.