Nanoporous Titanium Enriched with Calcium and Phosphorus Promotes Human Oral Osteoblast Bioactivity.

Implant surfaces are known to influence the osseointegration process; therefore, their modifications represent an important subject of investigation. On this basis, the purpose of this study was to evaluate the response of human oral osteoblasts (hOBs) to three different GR4 titanium discs: Machined, double-etched (Osteopore), and double-etched, surface-enriched with calcium and phosphorus (CaP) (Nanopore). The superficial topography was investigated with scanning electron microscopy (SEM) and the sessile drop technique. To test cellular response and osteoinductive properties, the following points were evaluated: (i) proliferation by MTS assay after 2 and 5 days; (ii) adhesion by multiphoton microscopy at day 2; (iii) the interaction with Ti discs by blue toluidine staining at day 5; (iv) alkaline phosphatase (ALP) activity by ALP assay after 14 days; (v) calcium deposition by alizarin red staining and by cetylpyridinium chloride after 14 days. The SEM analysis showed that Nanopore and Osteopore surfaces were characterized by the same micro-topography. Nanopore and Osteopore discs, compared to Machined, stimulated higher osteoblast proliferation and showed more osteoinductive properties by promoting the ALP activity and calcium deposition. In conclusion, the CaP treatment on DAE surfaces seemed to favor the oral osteoblast response, encouraging their use for in vivo applications.

Implant Placement in Patients under Treatment with Rivaroxaban: A Retrospective Clinical Study.

The management of patients under treatment with Direct Oral Anticoagulants (DOACs) has led clinicians to deal with two clinical issues, such as the hemorrhagic risk in case of non-interruption or the risk of thromboembolism in case of suspension of the treatment. The primary aim of this retrospective study was to evaluate the incidence of perioperative bleeding events and healing complications in patients who were under treatment with Rivaroxaban and who received dental implants and immediate prosthetic restoration. Patients treated with Rivaroxaban (Xarelto 20 mg daily) and who needed implant rehabilitation were selected. Four to six implants were placed in mandibular healed sites or fresh extraction sockets. All patients, in agreement with their physicians, interrupted the medication for 24 h and received implants and immediate restorations. Twelve patients and 57 implants were analyzed in the study. No major postoperative bleeding events were reported. Three patients (25%) presented slight immediate postoperative bleeding controlled with compression only. The implant and prosthetic survival rate were both 100% after 1 year. Within the limitations of this study, multiple implant placement with an immediate loading can be performed without any significant complication with a 24 h discontinuation of Rivaroxaban, in conjunction with the patient's physician.

Osteo-regeneration personalized for children by rapid maxillary expansion: an imaging study based on synchrotron radiation microtomography.

BACKGROUND: Personalized maxillary expansion procedure has been proposed to correct maxillary transversal deficiency; different protocols of stem cell activation have been suggested and rapid maxillary expansion (RME) is the most commonly used among clinicians. The present study aimed to quantify in three-dimensions (3D) the osteo-regeneration of the midpalatal suture in children submitted to RME. METHODS: Three patients (mean age 8.3 ± 0.9 years) were enrolled in the study to preform biopsy of midpalatal suture. Two patients (subjects 1 and 2) were subjected to RME before biopsy. The third patient did not need maxillary expansion treatment and was enrolled as control (subject 3). Midpalatal suture samples were harvested 7 days after RME in subject 1, and 30 days after RME in subject 2. The samples were harvested with the clinical aim to remove bone for the supernumerary tooth extraction. When possible, maxillary suture and bone margins were both included in the sample. All the biopsies were evaluated by complementary imaging techniques, namely Synchrotron Radiation-based X-ray microtomography (microCT) and comparative light and electron microscopy. RESULTS: In agreement with microscopy, it was detected by microCT a relevant amount of newly formed bone both 7 days and 30 days after RME, with bone growth and a progressive mineralization, even if still immature respect to the control, also 30 days after RME. Interestingly, the microCT showed that the new bone was strongly connected and cross-linked, without a preferential orientation perpendicular to the suture's long axis (previously hypothesized by histology), but with well-organized and rather isotropic 3D trabeculae. CONCLUSIONS: The microCT imaging revealed, for the first time to the authors' knowledge, the 3D bone regeneration in children submitted to RME.

Hemostasis control in endodontic surgery: a comparative study of calcium sulfate versus gauzes and versus ferric sulfate.

INTRODUCTION: Calcium sulfate (CaS) is a simple, biocompatible material with a long history of safe use in different fields of medicine. CaS is a rapidly resorbing material that leaves behind a calcium phosphate lattice, which promotes bone regeneration and hemostasis. The aim of this study was a clinical evaluation of the hemostatic effect of CaS hemi-hydrate (CaSO4), commonly known as plaster of Paris, in endodontic surgery. METHODS: Twenty-four patients with 31 periradicular lesions were enrolled in this study. The apical roots were exposed, and the bleeding would have made it difficult to correctly fill the root-end cavities. To avoid such an inconvenience, the teeth were divided into 3 groups. Hemostasis was attempted by using CaS in 11 teeth (group I), gauze tamponade in another 10 teeth (group II), or 20% ferric sulfate in the last 10 teeth (group III). RESULTS: Control of the bleeding was achieved in all teeth of group I, whereas in group II adequate hemostasis was achieved in 3 of 10 cases and in group III in 6 of 10 cases. CONCLUSIONS: The use of CaS completely eliminated the bleeding, with a very good level of hemostasis.

Peri-implant bone regeneration with calcium sulfate: a light and transmission electron microscopy case report.

BACKGROUND: Calcium sulfate is a simple, biocompatible material with a very long, safe clinical history in several different fields of medicine. It is a rapidly resorbing material that leaves behind calcium phosphate lattice, which promotes bone regeneration. OBJECTIVE: The aim of this study was a histological and ultrastructural evaluation of the tissues in a peri-implant site regenerated with calcium sulfate. MATERIALS AND METHODS: The specimens were processed for observation under light and transmission electron microscopes. RESULTS: In light microscopy, trabecular bone was present. No remnants of calcium sulfate were present. Transmission electron microscopy showed, in the areas of the interface with the implant surface, features of mature bone with many osteocytes. An amorphous layer and/or osteoid seam separated this mature bone from the metal surface. CONCLUSION: The results confirm the high biocompatibility and rapid resorption of calcium sulfate.

Histologic evaluation of a provisional implant retrieved from man 7 months after placement in a sinus augmented with calcium sulphate: a case report.

Little is known about the in vivo healing processes at the interface of implants placed in different grafting materials. For optimal sinus augmentation, a bone graft substitute that can regenerate high-quality bone and enable the osseointegration of load-bearing titanium implants is needed in clinical practice. Calcium sulphate (CaS) is one of the oldest biomaterials used in medicine, but few studies have addressed its use as a sinus augmentation material in conjunction with simultaneous implant placement. The aim of the present study was to histologically evaluate an immediately loaded provisional implant retrieved 7 months after simultaneous placement in a human sinus grafted with CaS. During retrieval bone detached partially from one of the implants which precluded its use for histologic analysis. The second implant was completely surrounded by native and newly formed bone, and it underwent histologic evaluation. Lamellar bone, with small osteocyte lacunae, was present and in contact with the implant surface. No gaps, epithelial cells, or connective tissues were present at the bone-implant interface. No residual CaS was present. Bone-implant contact percentage was 55% +/- 8%. Of this percentage, 40% was represented by native bone and 15% by newly formed bone. CaS showed complete resorption and new bone formation in the maxillary sinus; this bone was found to be in close contact with the implant surface after immediate loading.

Bone regeneration with calcium sulfate: evidence for increased angiogenesis in rabbits.

Autologous bone is the preferred bone graft material because it carries proteins as bone-enhancing substrates, minerals, and vital bone cells. Calcium sulfate (CS) is a well-tolerated, biodegradable, osteoconductive bone graft substitute and is a reasonable alternative to autogenous bone graft. Blood vessels are an important component of bone formation and maintenance. The process of vascular induction is called angiogenesis, and it plays a key role in all regenerative processes. Bone tissue differentiation is related to the local presence of blood vessels. One method to evaluate the presence of blood vessels in a tissue is to count the microvessels to evaluate microvessel density (MVD). The aim of the present study was to conduct a comparative evaluation of microvessel density in sites treated with CS and autologous bone in rabbits, with or without e-PTFE nonresorbable membranes (Gore-Tex, Flagstaff, Ariz). Nine New Zealand rabbits, each weighing about 2.5 kg, were used in this experiment. Three 6-mm wide defects were created in each tibial metaphysis. The defects were filled in a random way. The defects of group 1 (3 rabbits) were filled with CS granules (Surgiplaster, Classimplant, Rome, Italy) and covered with e-PTFE membranes. The defects in group 2 (3 rabbits) were filled with CS granules (Surgiplaster). The defects in group 3 (3 rabbits) were filled with autologous bone. A total of 54 defects were filled (18 with CS and e-PTFE membranes, 18 with CS alone, and 18 with autologous bone). No postoperative deaths or complications occurred. All nine animals were sacrificed at 4 weeks. MVD results were as follows: in the first group, 9.88 +/- 4.613; in the second group, 7.92 +/- 1.998; and in the third group, 5.56 +/- 1.895. P = .000 was highly significant. Statistically significant differences were found between groups 1 and 3, 1 and 2, and 2 and 3. The presence of more blood vessels in the sites treated with CS could help to explain the good results reported in the literature with the use of CS.