*4.4. Patient No.4*

A 46-year-old woman with no known allergies or relevant medical or toxicological history came to the clinic due to discomfort in the upper-anterior area. She presented 12, 11, 21, and 22 with metal-ceramic crowns, endodontics, with apical lesions in all of them, and fistulas in the palatal area (Figure 13A). The patient explained that root canal retreatment had already been carried out on these teeth, so conservative treatment was ruled out and it was decided to extract all of them. A CBCT of the area was requested to assess the possible placement of immediate implants, but after observing the apical lesions (Figures 14 and 15), it was decided to place them in a second surgical phase. The 12, 11, 21, and 22 were extracted and an alveolar preservation with Bond Apatite® was performed according to the manufacturer's protocol, extraction, profuse curettage of the alveolus, placement of a Bond Apatite® syringe, compression with dry and sterile gauze, coverage with collagen sponge and cross stitches (Figure 15A–D). There were no intraoperative complications. Pharmacological recommendations and guidelines were delivered. A week later, the patient came to have the suture removed, reporting pain. On examination, alveolitis and loss of graft material were observed (Figure 15E). Amoxicillin/clavulanic acid 875/125 mg every 8 h × 7 days was prescribed. Periodic monthly check-ups were performed (Figure 13B–E) and at 4 months a new CBCT of the area was requested for implant planning, where good healing and maintenance of bone volume were observed (Figure 16). On the day of surgery, a trephine biopsy was taken in the regenerated area for histopathological analysis (Figure 17) and two 4.2 × 12 mm Microdent® Genius implants were placed in positions 12 and 22 following the drilling protocol for the commercial house (Figure 13F). The same pharmacological regimen was prescribed on the day of the extraction and monthly follow-up visits were scheduled. An immediate provisional screw-retained prosthesis was made and placed. Currently, he must undergo the second surgical phase and subsequent definitive prosthodontic rehabilitation.

**Figure 13.** (**A**) Preoperative IOPA; (**B**) Immediate postoperative IOPA; (**C**) One-week IOPA; (**D**) Onemonth IOPA; (**E**) Two months IOPA; (**F**) IOPA after implant placement.

**Figure 14.** Previous CBCT. (**A**) 12 (**B**) 11 (**C**) 21 (**D**) 22.

**Figure 15.** (**A**) Preoperative occlusal view; (**B**) Dental extractions; (**C**) Placement of Bond Apatite®; (**D**) Suture; (**E**) 7 days' follow-up; (**F**) 15 days' follow-up.

**Figure 16.** Postoperative CBCT after 4 months. (**A**) 12 (**B**) 11 (**C**) 21 (**D**) 22.

**Figure 17.** Few remains of inorganic material and abundant newly formed bone. (**A**) at 50× and (**B**) at 200×. Total bone length 6.63 mm, and clearly newformed bone indistinguishable from the rest 3.53 mm.
