Molecular, Cellular and Pharmaceutical Aspects of Bone Grafting Materials and Membranes During Maxillary Sinus-lift Procedures. Part 1: A General Overview.

Sinus augmentation procedure has been demonstrated to be a highly predictable treatment in posterior maxilla atrophy. All the surgical interventions in the maxillary region require deep knowledge of anatomy and possible anatomical variations. In this article, pre-operative and post- operative assessments of sinus cavity as well as novel approaches to deepen our knowledge of the behavior of bone substitute materials are described. The awareness of the patient's morphologic conditions enables exact planning of invasive surgery and aids to avoid complications. Pre- operative radiologic evaluation of the region before sinus lift is advisable both for a planning of the sinus augmentation and for selection and alignment of the optimum placement of implants. On the orthopantomography it is possible to measure the vertical dimension of graft, but not the volume and 3D changes. Cone-beam computed tomography (CBCT) has become the "gold standard" to plan a comprehensive implant treatment and to achieve a post-operative assessment. A computer-aided design/computer-aided manufacturing (CAD/CAM) technique is proposed to produce custom-made block grafts for sinus lift procedure, and a customized cutting guide to accurately place the lateral wall and ease membrane elevation. This procedure allows to reduce intervention time, to precisely adapt the scaffold, to reduce risk of complications and to improve operation quality. Recently, a novel approach has been used to deepen our knowledge of the behavior of BSBs: by means of synchrotron micro-tomography (SCT). It is a 3-D analyzing method, suitable to examine the dynamic and spatial arrangement of regenerative phenomena in complex anatomical structures such as bone, where tissues with several morphologies (alveolar process, unmineralized extracellular matrix, regenerated vessels, etc.) compete to achieve the final goal of bone regeneration.

Bisphosphonate therapy and osteonecrosis of the jaw complicated with a temporal abscess in an elderly woman with rheumatoid arthritis: a case report.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an adverse drug reaction described as the progressive destruction and death of bone tissue of the mandible or maxilla, in the course of bisphosphonate therapy. Orally administered bisphosphonates, widely used for the treatment of osteoporosis, are rarely associated with BRONJ. Instead, the risk greatly increases whether the patient is concomitantly taking steroid and/or immunosuppressant agents. The aims of this paper are to briefly discuss the evidence of the associations between bisphosphonate therapy and BRONJ, and the effects of co-occurring factors such as the presence of rheumatoid arthritis, dental surgery, and concomitant corticosteroid therapy. In particular, we present the case of an elderly woman with BRONJ suffering from rheumatoid arthritis, with a recent dental extraction and with a very unusual complication: a temporal abscess, who was successfully treated.

High temperature-treated bovine porous hydroxyapatite in sinus augmentation procedures: a case report.

Among the graft materials that can be used clinically, xenografts are the most common. Xenografts are of bovine, porcine, or equine origin and require the complete removal of proteins to avoid immunologic problems and the risk of transmission of prions, viruses, etc. Protein destruction can be achieved by a chemical procedure using organic solvents and heat treatment. After this process, a carbonated hydroxyapatite similar to human bone remains. The aim of this case report is to investigate the bone formation in a sinus augmentation procedure using a high temperature-treated bovine porous hydroxyapatite. A 58-year-old woman underwent bilateral sinus augmentation using this biomaterial. After 9 months, during stage-two surgery, two core biopsy specimens were retrieved and treated to obtain thin ground undecalcified sections. Microscopically, newly formed bone was present at the interface with most particles. The major portion of the particles appeared to be completely lined and surrounded by bone. No obvious signs of resorption were present on the biomaterial surface. No gaps or connective tissue were present at the bone-biomaterial interface. No inflammatory infiltrate or fibrous encapsulation of the particles was present. Histomorphometry showed that the percentages of newly formed bone, residual grafted particles, and marrow spaces were 25.1% ± 2.3%, 37.3% ± 1.1%, and 38.5% ± 3.1%, respectively. The excellent properties demonstrated by Endobon are probably a result of its particular hydroxyapatite porous microstructure with a high percentage of interconnected micropores that promote the ingrowth of osteogenic cells and vessels, making graft integration easier and faster.