Epistaxis as a marker of the unfavorable course of hypertension

The aim of this research was to study changes in the nasal mucosa vessels in hypertensive patients suffering from recurrent epistaxis. Patients and methods. 78 hypertensive patients aged between 50 and 70, admitted due to epistaxis, were studied. Diabetic, coagulopathic patients and those taking anticoagulants were excluded from the research. All the patients were divided into 2 groups: group 1 (46 people) with a single epistaxis, group 2 (32 people) with a recurrent epistaxis. At the admission, all the patients showed elevated blood pressure, yet the differences between the patients of group 1 and group 2 were not significant. 14 patients of group 2 did not reveal any source of hemorrhage due to a severely deviated septum. These patients underwent septoplasty followed by mucoperichondrium biopsy. Histological study of the samples showed multiple erosions within the epithelial layer, as well as necrotic patches spreading to the deeper mucous coat layers. The microvasculature showed dystrophic changes in the endothelium, its focal desquamation with basal membrane exposure and thrombocytes and erythrocytes adhesion at such places, erythrocyte aggregation, plasma separation, erythrocyte and fibrinous thrombi formation. Thus, the cause of epistaxis is not high blood pressure, but those changes in the nasal mucosa vessels promoted by long-term arterial hypertension.

Augmentation Stability of Guided Bone Regeneration for Peri-Implant Dehiscence Defects with L-shaped Porcine-Derived Block Bone Substitute

Block bone substitutes have better augmentation stability for guided bone regeneration (GBR) than particulate bone substitutes. This study sought to determine whether GBR with an L-shaped porcine block bone (DPBM-C) differs from GBR with an L-shaped bovine block bone (DBBM-C) based on clinical, radiographic, and volumetric outcomes for peri-implant dehiscence defects. A total of 42 peri-implant defects were grafted with 20 L-shaped DPBM-C and 22 DBBM-C groups. The horizontal and vertical thicknesses of the augmented hard tissue were measured using sagittal cone-beam computed tomography, and the volumetric tissue change was evaluated by stereolithography image superimposition. Postoperative discomfort, early wound healing outcomes, and implant stability were also assessed. Among the clinical (subjective pain and swelling, wound dehiscence, membrane exposure, and periotest values), radiographic (changes in horizontal and vertical hard tissue thickness), and volumetric parameters of the L-shaped DPBM-C and DBBM-C groups during the healing period, only the periotest values showed a statistically significant difference (0.67 ± 1.19, p = 0.042). Within the limitations of this study, an L-shaped DPBM-C is not inferior to an L-shaped DBBM-C based on their clinical, radiographic, and volumetric outcomes for GBR of peri-implant dehiscence defects.

Rehabilitation of Atrophic Posterior Mandible with Vertical Ridge Augmentation with Resorbable Membrane: Case Report with 3-Year Follow-up

Background: The placement of implants in the posterior mandible with the vertical bone defect can be associated with inadequate crown height space. Therefore, the vertical bone reconstruction of these defects is often necessary, although this procedure is technically challenging. Methods: A 49-year-old patient attended a private dental office for rehabilitation of an atrophic posterior mandible. The clinical and tomographic findings show absence of teeth #36, #37, #46, #47, and #48 with severe atrophy. Vertical bone augmentation was performed by using the guided bone regeneration technique with pericardium resorbable membrane followed by placement of short implants. The free gingival graft was performed, and after three months, screw-retained lithium disilicate single ceramic crowns were manufactured. Results: After a 3-years follow-up, bone loss around the implants or presence of gingival inflammation was not observed, and the prosthesis adaptation was found to have no alteration either. Therefore, aesthetics, as well as masticatory and speech functions, were preserved. Conclusion: There was no bone loss around the implants. The association between vertically guided bone regeneration using pericardium resorbable membrane is an alternative technique, and it avoids complications related to non-resorbable membrane exposure. It was shown to be viable after a 3-year follow-up.

Effects of Heparin and Bivalirudin on Thrombin-Induced Platelet Activation: Differential Modulation of PAR Signaling Drives Divergent Prothrombotic Responses

Heparin and bivalirudin are widely used as anticoagulants in the setting of acute thrombosis. In this study, we investigated how these drugs affect the ability of thrombin to generate a prothrombotic platelet response via activation of the protease-activated receptors (PARs) 1 and 4. We examined the effects of heparin/antithrombin and bivalirudin on PAR1- and PAR4-mediated intracellular calcium mobilization, aggregation, α-granule release, and procoagulant membrane exposure in platelets exposed to thrombin concentrations likely to be encountered in the thrombus microenvironment during thrombosis. At physiological antithrombin levels, heparin treatment resulted in complete and sustained inhibition of thrombin-induced PAR4-mediated platelet activation, but transient PAR1 signaling was sufficient to elicit significant α-granule release and platelet aggregation. In contrast, bivalirudin treatment resulted in rapid and profound inhibition of signaling from both PAR receptors, followed by a delayed phase of PAR4-mediated platelet activation, resulting in a robust prothrombotic response. Combination treatment with bivalirudin and subtherapeutic concentrations of heparin completely inhibited the residual platelet activation observed with single drug treatment at all time-points. Our results show that heparin and bivalirudin have different and complementary inhibitory effects on the activation of PAR1 and PAR4 by thrombin.

Comparing the Efficacy of a Microperforated Titanium Membrane for Guided Bone Regeneration with an Existing Mesh Retainer in Dog Mandibles

Acute-type lateral ridge defects (25 mm × 6 mm × 5 mm) were bilaterally created in the mandibles of four dogs (two defects per animal). The defects were reconstructed with particulate autologous bone and covered with a microperforated titanium membrane (Ti-honeycomb membrane, TiHM) or an existing conventional titanium mesh as control. The samples were dissected after 16 weeks postoperatively and processed for radiographic, histologic, and histomorphometric analyses. Regenerated tissue and bone volume were significantly larger in the TiHM group than in the control group (p = 0.05; p = 0.049). In contrast, bone mineral density was similar between the two groups. Histomorphometric analysis revealed that the regenerated bone area and calcific osseous area were larger in the TiHM group than in the control group; however, the differences were not significant. The efficacy of TiHM was generally satisfactory with the potential to become a standard tool for the GBR procedure; however, early membrane exposure will be a major problem to overcome.

A Simple Technique for Descemet Membrane Exposure in Deep Anterior Lamellar Keratoplasty Using the Transconjunctival Single-plane Sclerocorneal Incision

Background: To describe a simple technique for Descemet membrane exposure during deep anterior lamellar keratoplasty (DALK).Methods: As a prospective interventional case series, consecutive patients who underwent DALK were enrolled. The technique involved the separation of the Descemet membrane by injecting air and ophthalmic viscosurgical devices from the point where transconjunctival single-plane sclerocorneal incision with the slit knife is terminated prior to perforation using a mirror image. Descemet membrane exposure success rates and the incidence of intra- and postoperative complications were analyzed. Outcomes of successful DALK procedures, which were not converted to penetrating keratoplasty, were analyzed by evaluating best corrected visual acuity (BCVA; converted to logarithm of the minimum angle of resolution [logMAR]) and graft survival.Results: We included 11 eyes from 11 patients (seven males and four females; 53.6 ± 16.1 years; mean follow-up duration, 26.1 weeks [6–51 weeks]). Ten surgeries were successful in Descemet membrane exposure without rupture, eight were successful in big-bubble formation, and two were finally successful in Descemet membrane exposure after a failed big-bubble. The DALK procedure for only one eye was converted to a penetrating keratoplasty owing to a tear in the Descemet membrane. BCVA improved from 0.83 ± 0.38 logMAR preoperatively to 0.24 ± 0.12 logMAR postoperatively (n=10, p < 0.001). There was no primary graft failure.Conclusion: This simple technique of transconjunctival single-plane sclerocorneal incision could be very useful for exposing the Descemet membrane during DALK.

In vitro degradation, biocompatibility and antibacterial property of pure Zinc: Assessing the potential of Zn as a guided bone regeneration membrane

Membrane exposure is a common complication after guided bone regeneration (GBR) procedure and has a detrimental influence on the bone regeneration outcomes, while the commercially available GBR membranes show limited...

Management of Membrane Exposure Utilizing Concentrated Growth Factor (CFG) in Guided Bone Regeneration: A Clinical Report

Introduction: This is a clinical case of a healthy woman with a missing upper right central incisor (#8) who requested a permanent prosthetic replacement due to endodontic failure. Clinically, she was presented with thin edentulous ridges and fibrous gingival tissue and minimal or compromised alveolar bone segment on the buccal profile as detected on cone-beam computed tomography (CBCT). Case Report: The conventional treatment approach is to add pink porcelain; however, rarely does the prosthetic gingiva substitute blend well with the existing oral profile. Therefore,Guided Bone Regeneration (GBR) was done instead on #8 using the allograft [RegenOss, Neobiotech] and PTFE membrane. Upon examination, membrane exposure was detected, and the size was found to be increased in follow-up visits. The membrane was replaced with a Concentrated Growth Factor [CGF] and sutured at the site of the defect. After 12 months, a vertical and horizontal bone with adequate soft tissue emergence profile was achieved clinically, radiographically, and digitally. The delayed removal of the exposed membrane provided more time for initial bone regeneration in GBR. The replacement barrier of an exposed membrane using CGF is considered an innovative procedure with the cellular content providing vascularization and regeneration. Conclusion: This case concludes that CGF can be a viable alternative material to enhance GBR outcome in replacing exposed membranes.

Comparison of the Efficiency of Two Novel Guided Bone Regeneration Devices in the Rabbit Calvarial Model

Background. Creating a secluded large space using guided bone regeneration (GBR) is a novel osteogenesis technique used in the prevention of premature membrane exposure complications. However, this technique is not considered clinically feasible. Objectives. This study aimed to compare the outcome of the insertion of two novel GBR devices in a rabbit calvarial model in terms of mode of action, simplicity, and amount of new space and bone gained. Materials and Methods. The expansible GBR (EGBR) device, composed mainly of a titanium plate, silicone membrane, and activation screw, was inserted beneath the periosteum in the calvarial area of eight rabbits. The smart GBR (SGBR) device, composed of silicone sheets and Nitinol strips, were inserted beneath the periosteum in the calvarial area of another 10 rabbits. Half of each group was sacrificed 2 months after surgery, and the other half was sacrificed after 4 months. Results. Histological and microradiographical analysis showed that, at 2 months, the EGBR device achieved a mean space gain of 207.2 mm3, a mean bone volume of 68.2 mm3, and a mean maximum bone height of 1.9 mm. Values for the same parameters at 4 months were 202.1 mm3, 70.3 mm3, and 1.6 mm, respectively. The SGBR device had significantly higher P < 0.05 mean space gain (238.2 mm3; 239.5 mm3), bone volume (112.9 mm3, 107.7 mm3), and bone height (2.7 mm; 2.6 mm) than the EGBR device at 2 and 4 months, respectively. Conclusion. Both devices proved to be effective in augmenting bone vertically through the application of GBR and soft tissue expansion processes. However, the SGBR device was more efficient in terms of mode of action, simplicity, and amount of bone created in the new space.