The aim of the present study is to compare the histological aspects of bone formation in atrophic posterior mandibles augmented by autologous bone block from chin area with corticocancellous bone block allograft used as inlays with the sandwich technique.Materials and Methods. Sixteen patients with bilateral partial edentulism in the posterior mandible were selected. The residual bone height, preliminarily measured by computed tomography scans, ranged between 5 and 7 mm from the inferior alveolar nerve. All patients required regeneration procedure with autologous bone block from chin area (control group) versus bone block allograft Puros (Zimmer Dental, 1900 Aston Avenue, Carlsbad, CA, USA) (test group). Histological and histomorphometric samples were collected at the time of implant positioning in order to analyze the percentage of newly formed bone, the residual graft material, and marrow spaces/soft tissue.Results. No statistically significant differences between the two groups were found regarding the percentage of newly formed bone. The percentage of residual grafted material was significantly higher in the test group, whilst the percentage of marrow spaces was higher in control group.Conclusions. In conclusion, both procedures supported good results, although the use of bone blocks allograft was less invasive and preferable than harvesting bone from the mental symphysis.

Background. The “root membrane” (RM) is a technique that has become popular among implantologists for placement of immediate implants in the anterior maxilla. Purpose. To present histologic evidence of an immediate implant placed in the human anterior maxilla, according to the RM technique, and retrieved after five years. Methods. A fixture, along with the surrounding tissues, was retrieved from the anterior maxilla of a 68-year-old patient, who had been treated five years earlier with immediate implant placement and RM technique. The specimen was processed for histologic/histomorphometric evaluation. Results. The buccal bone plate was maintained without any resorption; a healthy periodontal ligament was evidenced. The implant showed osseointegration, with a high percentage of bone-to-implant contact (BIC = 76.2%). With regard to the space between the RM and the implant, the apical and medial thirds were filled with compact, mature bone; the coronal third was colonized by noninfiltrated connective tissue. Conclusions. The RM technique appears to be effective in preventing bone resorption of the buccal bone plate of the human anterior maxilla, five years after the placement of an immediate implant.

Background: The aim of the present review was to assess the histological and histomorphometrical data from the paper published by our Laboratory on peri-implant bone in dental implants in different loading conditions. Methods: The papers published in different implant loading conditions, in dental implants retrieved from humans, and in the Hard Tissues Research Center of the University of Chieti-Pescara, Italy, were screened on MEDLINE/PubMed, Embase, Scopus, and other electronic databases until 31 December 2018. Only articles that reported the histological and histomorphometrical values of the Bone-Implant Contact (BIC) were selected. Results: The system selection provided a total of 155 papers. The manuscripts included for the narrative review were 57. These papers provided histological and histomorphometrical data. Conclusions: The bone remodeling around dental implants was found to be a dynamic process; loading changed the microstructure of the peri-implant bone; and implants were found to provide a successful function, over several decades, with different range of degrees of BIC in vivo (varying from a little more than 30% to a little more than 90%). Loaded implants presented a 10%–12% higher BIC values when compared to submerged, unloaded implants, and rougher surfaces had, on average, about a 10% higher BIC than machined surfaces.

Background: Little is known about the healing pattern and the osseointegration processes at the interface of implants placed into different grafting materials in man. Anorganic bovine bone (ABB) is a xenogenic material with a high biocompatibility and osteoconductivity. Methods: A 47‐year‐old patient underwent a monolateral sinus‐augmentation procedure using 100% ABB. Two titanium dental implants were inserted at the same time as the grafting procedure. After 6 months, a fixed prosthetic restoration was placed. After a 5‐year loading period, the distal implant fractured, and the implant was removed with a 5‐mm trephine bur. Results: At low magnification, in the peri‐implant bone in the grafted area, many particles of ABB were still present. Bone was always interposed between the ABB particles and the metal surface, and in no case were the graft particles in contact with the implant. No acute or chronic inflammatory cell infiltrate or foreign body reactions were present around the particles or at the bone–implant interface. The tissues around the implant were composed of 40% ± 2.4% bone, 12% ± 2.9% ABB particles, and 50% ± 6.2% marrow spaces. The percentage of bone‐to‐implant contact was 48.6% ± 3.7%. Conclusions: A high percentage (∼50%) of direct contact between bone and implant, without the interposition of graft material particles, was present. ABB had enabled implant integration to take place, which had remained stable for 5 years.