• Case Title: Simultaneous Extraction and Transcrestal Hydraulic Sinus Floor Elevation in Severely Deficient Residual Bone Height: A Case Report
• Academic Presentation: Presented as a poster at the 2026 Joint Sichuan-Chongqing Dental Implantology Annual Conference, the 2026 Academic Annual Meeting of the Oral Implantology Committee of the Sichuan Stomatological Association, and the 5th Chongqing Dental Implantology Conference. (Figure: Dr. Bai Ruqiang presenting his poster on transcrestal hydraulic sinus floor elevation at the conference).
  
• Lead Specialist: Dr. Bai Ruqiang (Chengdu Anyu Dental Implant Hospital)
• Patient Profile: 44-year-old female presenting with residual roots and periapical periodontitis at the maxillary left first molar.
• Anatomical Challenge: CBCT imaging revealed marked sinus pneumatization with a residual bone height (RBH) of approximately 2.5 mm and a partial buccal bone wall defect.
• Treatment Approach: Tooth Extraction + Transcrestal Hydraulic Sinus Elevation (performed concurrently in the same session) + Viscous Bone Grafting (CGF + Allograft) + Delayed Implant Placement

Case Summary:

When upper posterior teeth require extraction, severe bone deficiency beneath the sinus cavity often necessitates a second-stage or lateral window sinus elevation, which is frequently associated with increased postoperative reactions. In this clinical case, Dr. Bai Ruqiang performed a transcrestal hydraulic sinus elevation concurrently with tooth extraction in the same session. By utilizing Concentrated Growth Factors (CGF) combined with an allograft bone substitute to form a viscous bone graft (sticky bone), the residual bone height (RBH) at the surgical site increased to approximately 12.0 mm at 10 months postoperatively, avoiding the need for a secondary lateral window procedure in this patient. Following bone healing, a dental implant was placed with good primary stability, satisfactory three-dimensional positioning, and stable osseointegration. Final restoration was completed 7 months after implant placement. At the 1-year post-restoration follow-up, the patient exhibited healthy peri-implant soft tissue, normal masticatory function, and no sinus complications or other adverse events.

• Note: Written informed consent was obtained from the patient for the publication of this clinical case report and accompanying imaging.

• Diagnostic Assessment: CBCT sagittal analysis confirmed residual roots of the maxillary left first molar with periapical periodontitis, marked sinus pneumatization, a residual bone height (RBH) of approximately 2.5 mm, and a partial defect of the buccal bone wall.
• Atraumatic Extraction & Hydraulic Elevation: The tooth was sectioned and extracted atraumatically. Through the furcation area of the alveolar crest, the sinus floor was penetrated, and a dedicated hydraulic elevation instrument was used to perform transcrestal hydraulic sinus elevation in a controlled manner without tension on the membrane.
• Grafting & Closure Protocol: A viscous bone graft (sticky bone)—prepared by blending an allograft bone substitute with Concentrated Growth Factors (CGF)—was packed into the elevated sinus cavity. CGF membranes were placed over the extraction socket, and the wound was closed with tension-free sutures to promote soft-tissue healing and seal the surgical site.
• Bone Healing & Implant Placement: At 10 months postoperatively, CBCT confirmed favorable bone formation, with the residual bone height (RBH) at the surgical site increasing to approximately 12.0 mm. After bone healing, a dental implant was inserted, achieving good primary stability, satisfactory three-dimensional positioning, and subsequent stable osseointegration.
• Restoration & Longitudinal Follow-Up: The final restoration was completed 7 months after implant placement. At the 1-year post-restoration follow-up, the patient showed stable peri-implant bone levels, healthy soft tissue, and normal masticatory function; no sinus complications or other adverse events were observed.

In this case, anticipating insufficient residual bone height (RBH) prior to tooth extraction allowed the surgical team to perform a transcrestal hydraulic sinus elevation concurrently with extraction. In this patient, this approach avoided a second-stage lateral window sinus elevation and reduced postoperative reactions associated with external sinus lifts, while potentially making the procedure less technique-sensitive. This case provides a new perspective on the timing of transcrestal sinus floor elevation.