Analysis of peri-implant bone tissue between hydrophilic and rough implant surfaces in spontaneously hypertensive rats treated with losartan.

OBJECTIVES: to evaluate the morphological and functional characteristics of the peri-implant bone tissue that was formed during the healing process by the placement implants using two different surface treatments: hydrophilic Acqua™ (ACQ) and rough NeoPoros™ (NEO), in spontaneously hypertensive (SHR) and normotensive rats (Wistar) whether or not treated with losartan. METHODOLOGY: In total, 96 male rats (48 Wistar and 48 SHR) were divided into eight subgroups: absolute control rough (COA NEO), absolute control hydrophilic (COA ACQ), losartan control rough (COL NEO), losartan control hydrophilic (COL ACQ), SHR absolute rough (SHR NEO), SHR absolute hydrophilic (SHR ACQ), SHR losartan rough (SHRL NEO), and SHR losartan hydrophilic (SHRL ACQ). The rats medicated with losartan received daily doses of the medication. NeoPoros™ and Acqua™ implants were installed in the tibiae of the rats. After 14 and 42 days of the surgery, the fluorochromes calcein and alizarin were injected in the rats. The animals were euthanized 67 days after treatment. The collected samples were analyzed by immunohistochemistry, biomechanics, microcomputerized tomography, and laser confocal scanning microscopy analysis. RESULTS: The osteocalcin (OC) and vascular endothelium growth factor (VEGF) proteins had moderate expression in the SHRL ACQ subgroup. The same subgroup also had the highest implant removal torque. Regarding microarchitectural characteristics, a greater number of trabeculae was noted in the control animals that were treated with losartan. In the bone mineralization activity, it was observed that the Acqua™ surface triggered higher values of MAR (mineral apposition rate) in the COA, COL, and SHRL groups (p<0.05). CONCLUSION: the two implant surface types showed similar responses regarding the characteristics of the peri-implant bone tissue, even though the ACQ surface seems to improve the early stages of osseointegration.

One-Stage Approach to Rehabilitate a Hopeless Tooth in the Maxilla by Means of Immediate Dentoalveolar Restoration: Surgical and Prosthetic Considerations.

Contemporary dentistry has increased the demand for predictable functional and esthetic results in a short period of time without compromising the long-term success of rehabilitation. Recent advances in surgical techniques have provided alternatives that allow the prosthetic rehabilitation of complex implant-supported cases through minimally invasive techniques. In this context, immediate dentoalveolar restoration (IDR) was described aiming at restoring function and esthetics through the reconstruction of lost periodontal tissues followed by immediate implant placement in order to minimize treatment time and surgical morbidity in a one-stage approach. Therefore, the aim of this clinical case is to describe the reconstruction and rehabilitation of a hopeless tooth in the maxillary region in a one-stage approach by means of IDR. The proposed steps to rehabilitate the case involved atraumatic dental extraction, immediate implant placement, and hard tissue augmentation by means of cortical-medullary bone graft harvested from the maxillary tuberosity. Afterwards, a provisional restoration was manufactured and installed to the implant allowing immediate prosthesis provisionalization and function in the same operatory time. Six months after the surgical procedure, the final prosthesis was manufactured and installed. The follow-up of nine years demonstrated the preservation of hard and soft tissue without tissue alteration and a successful esthetic outcome. The surgical protocol used allowed the ideal three-dimensional placement of the implant with the restoration of the bone buccal wall, favoring the esthetic and functional outcome of the case with harmony between white and pink esthetics. In conclusion, the employed treatment validated immediate implant-supported restoration of the missing tooth with high predictability. Furthermore, this protocol resulted in fewer surgical interventions, regeneration, and preservation of peri-implant tissues reaching the patient's expectations.

Comparison of different bone substitutes in the repair of rat calvaria critical size defects: questioning the need for alveolar ridge presentation.

OBJECTIVE: This study aimed to evaluate the effectiveness of biomaterials in bone healing of critical bone defects created by piezoelectric surgery in rat calvaria. METHOD AND MATERIALS: Histomorphologic analysis was performed to assess bone regeneration and tissue response. Fifty animals were randomized into five groups with one of the following treatments: Control group (n = 10), spontaneous blood clot formation with no bone fill; BO group (Bio-Oss, Geistlich Pharma; n = 10), defects were filled with bovine medullary bone substitute; BF group (Bonefill, Bionnovation; n = 10), defects were filled with bovine cortical bone substitute; hydroxyapatite group (n = 10), defects were filled with hydroxyapatite; calcium sulfate group (n = 10), defects were filled with calcium sulfate. Five animals from each group were euthanized at 30 and 45 days. The histomorphometry calculated the percentage of the new bone formation in the bone defect. RESULTS: All data obtained were evaluated statistically considering P < .05 as statistically significant. The results demonstrated the potential of all biomaterials for enhancing bone regeneration. The findings showed no statistical differences between all the biomaterials at 30 and 45 days including the control group without bone grafting. CONCLUSION: In conclusion, the tested biomaterials presented an estimated capacity of osteoconduction, statistically nonsignificant between them. In addition, the selection of biomaterial should consider the specific clinical aspect, resorption rates, size of the particle, and desired bone healing responses. It is important to emphasize that in some cases, using no bone filler might provide comparable results with reduced cost and possible complications questioning the very frequent use of ridge presentation procedures.

Analysis of peri-implant bone tissue between hydrophilic and rough implant surfaces in spontaneously hypertensive rats treated with losartan

Abstract Hypertensive individuals present alterations in their calcium metabolism that consequently decrease the concentration of this mineral in the bone tissue. Objectives to evaluate the morphological and functional characteristics of the peri-implant bone tissue that was formed during the healing process by the placement implants using two different surface treatments: hydrophilic Acqua™ (ACQ) and rough NeoPoros™ (NEO), in spontaneously hypertensive (SHR) and normotensive rats (Wistar) whether or not treated with losartan. Methodology In total, 96 male rats (48 Wistar and 48 SHR) were divided into eight subgroups: absolute control rough (COA NEO), absolute control hydrophilic (COA ACQ), losartan control rough (COL NEO), losartan control hydrophilic (COL ACQ), SHR absolute rough (SHR NEO), SHR absolute hydrophilic (SHR ACQ), SHR losartan rough (SHRL NEO), and SHR losartan hydrophilic (SHRL ACQ). The rats medicated with losartan received daily doses of the medication. NeoPoros™ and Acqua™ implants were installed in the tibiae of the rats. After 14 and 42 days of the surgery, the fluorochromes calcein and alizarin were injected in the rats. The animals were euthanized 67 days after treatment. The collected samples were analyzed by immunohistochemistry, biomechanics, microcomputerized tomography, and laser confocal scanning microscopy analysis. Results The osteocalcin (OC) and vascular endothelium growth factor (VEGF) proteins had moderate expression in the SHRL ACQ subgroup. The same subgroup also had the highest implant removal torque. Regarding microarchitectural characteristics, a greater number of trabeculae was noted in the control animals that were treated with losartan. In the bone mineralization activity, it was observed that the Acqua™ surface triggered higher values of MAR (mineral apposition rate) in the COA, COL, and SHRL groups (p<0.05). Conclusion the two implant surface types showed similar responses regarding the characteristics of the peri-implant bone tissue, even though the ACQ surface seems to improve the early stages of osseointegration.

Estrogen Deficiency Impairs Osseointegration in Hypertensive Rats Even Treated with Alendronate Coated on the Implant Surface.

Hypertension and estrogen deficiency can affect bone metabolism and therefore increase the risk of osseointegration. Antihypertensive drugs such as losartan not only control blood pressure but also enhance bone healing. In addition, alendronate sodium is widely used to treat postmenopausal osteoporosis. Hence, we evaluated the effect of systemic antihypertensive and local alendronate coted on implants on osseointegration under hypertensive and estrogen-deficiency conditions. A total of 64 spontaneously hypertensive rats (SHRs) treated with losartan were randomly divided according to the estrogen-deficiency induction by ovariectomy (OVX) or not (SHAM), and whether the implant surface was coated with sodium alendronate (ALE) or not, resulting in four groups: SHR SHAM, SHR SHAM ALE, SHR OVX, and SHR OVX ALE. The removal torque, microcomputed tomography, and epifluorescence microscopy were the adopted analyses. The hypertensive and estrogen-deficiency animals presented a lower removal torque even when treated with alendronate on implant surface. The microcomputed tomography revealed a higher bone volume and bone-to-implant contact in the SHRs than the SHR OVX rats. Epifluorescence showed a decreased mineral apposition ratio in the SHR OVX ALE group. The data presented indicate that estrogen deficiency impairs osseointegration in hypertensive rats; in addition, alendronate coated on the implant surface does not fully reverse this impaired condition caused by estrogen deficiency.

The Relationship between Hypertension and Periodontitis: A Cross-Sectional Study.

Recent evidence suggests an association between hypertension and periodontitis, although the pathways and implications underlying both chronic conditions are still poorly understood. Therefore, the aim of this study was to evaluate the relationship between hypertension and periodontitis through an observational clinical study using periodontal, physical, and biochemical analyses in hypertensive and non-hypertensive individuals with periodontitis. A total of one hundred patients were divided into two groups. The first group was hypertensive patients with periodontitis. The second group was non-hypertensive patients with periodontitis. Periodontal parameters of probing depth, bleeding on probing, and clinical attachment level were evaluated. The systolic, diastolic, mean, and differential blood pressure were measured in the physical examination. In addition, body mass index and waist-hip ratio were verified. Biochemical tests for glycated hemoglobin, fasting blood glucose, estimated blood glucose, total cholesterol, high-density lipoprotein, creatinine, glutamate pyruvate transaminase, glutamic oxaloacetic transaminase, and C-reactive protein were evaluated. The data were submitted for statistical analysis (α = 0.05%). The results of this study demonstrated that patients with cardiovascular disease did not present with worse periodontal clinical parameters in the conditions studied. However, it is important to bear in mind that this cross-sectional study has some inherent limitations to its design; therefore, to study the relationship between hypertension and periodontitis further, an interventional randomized clinical trial should be conducted.

A randomised trial of the bone formation after maxillary sinus floor augmentation with bovine hydroxyapatite (Cerabone®) and Photobiomodulation: histomorphometric and immunohistochemical analysis.

Background: The use of non-autogenous biomaterial to increase bone height in the maxillary sinus has been shown to be effective, but the results are still inconclusive. Material and Methods: Eight participants were selected and included in the research. After surgical access with osteotomy on the lateral wall of both maxillary sinuses, these were filled with Cerabone®. Then, by blind randomization, they received one of the following treatments: Filling with Cerabone® (Control group); treatment with Photobiomodulation (PBM), filling with Cerabone® and treatment with low-power laser (PBM group). Biopsies were obtained 30 days after the surgery, using a 2.8 mm internal diameter trephine bur. Qualitative and quantitative histological analyzes were performed and immunohistochemical analyzes of osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) were performed with scores for each of the biological events. Results: The Cerabone® biomaterial demonstrated a high degree of biocompatibility. New bone formation was observed in both groups. In the PBM group, there was greater bone formation and newly formed tissue in an advanced state of bone maturation. The immunostaining of OCN was greater at 30 days in the PBM group than in the control. There was no significant difference in TRAP immunostaining at 30 days between the groups. Conclusions: Low-power laser-mediated by PBM promoted greater bone formation; the newly formed tissue showed a more advanced state of bone maturation in maxillary sinuses filled with Cerabone® biomaterial and treatment with PBM, within the 30-day evaluation period. Key words:Sinus floor augmentation, dental implants, bone and bones, low-level light therapy.

The Risk of Osseointegration in the Coronavirus Disease 19 Pandemic.

ABSTRACT: Coronavirus disease 19 (COVID-19) is associated with respiratory complications but also with alterations on bone metabolism. Coronavirus disease 19, therefore, might be a risk factor for osseointegration. Recent studies suggest that severe acute respiratory syndrome coronavirus 2 is related with bone abnormalities mainly for act via renin-angiotensin system. This report aims to list the bone alterations caused by coronavirus disease 19 and the possible consequences on the peri-implant bone healing. The current data add to the accumulating knowledge that coronavirus disease 19 may negatively impact the osseointegration and it requires further research.

Different Stages of Alveolar Bone Repair Process Are Compromised in the Type 2 Diabetes Condition: An Experimental Study in Rats.

The aim of this study was to analyze the stages of the alveolar bone repair in type 2 diabetic rats evaluating the mechanism of mineralization and bone remodeling processes after dental extraction. Forty-eight rats were divided into normoglycemic (NG) and type 2 diabetes (T2D) groups. The upper right incisor was extracted and after 3, 7, 14 and 42 days the animals were euthanized. The following analyses were performed: immunolabeling against antibodies TNFα, TGFß, IL6, WNT, OCN and TRAP, collagen fibers maturation, microtomography and confocal microscopy. Data were submitted to statistical analysis. The immunolabeling analysis showed that the T2D presented a more pronounced alveolar inflammation than NG. Labeling of proteins responsible for bone formation and mineralization was higher in NG than T2D, which presented greater resorptive activity characterized by TRAP labeling. Also, T2D group showed a decrease in the amount of collagen fibers. Micro-CT analysis showed that T2D causes a decrease in bone volume percentage due to deficient trabecular parameters and higher porosity. The T2D bone dynamics show a loss in bone remodeling process. T2D prolongs the local inflammatory process, which impairs the organization and maturation of collagen fibers, delaying bone formation that generates impact on mineralization and bone turnover.

Technical Strategy of Bone Graft Augmentation in the Anterior Maxilla.

Bone graft augmentation in the anterior maxilla has a high successful rate. However, suture dehiscence and consequent bone graft exposure can compromise and fail this procedure. Therefore, this article presents a new strategy of closure technique to guarantee the bone graft augmentation. The sutures occur in muscular and mucous planes to avoid suture tension, thus decreasing complications of bone graft augmentation in the anterior maxilla.

Losartan improves alveolar bone dynamics in normotensive rats but not in hypertensive rats.

OBJECTIVES: Hypertension is one of the main causes of premature death in the world; also, it is associated with several bone alterations. Preclinical studies have demonstrated delayed alveolar bone healing in hypertensive rats. However, losartan has been favorable for consolidation of bone grafts and reduction in active periodontitis. Therefore, losartan is suggested to be effective in bone formation stages, as well as in the synthesis of matrix proteins and mineralization. To evaluate the alveolar bone dynamics in hypertensive rats treated with losartan by laser confocal microscopy and histological analysis. METHODOLOGY: Thirty-two rats, 16 spontaneously hypertensive rats (SHR) and 16 Wistar albinus rats, treated or not with losartan (30 mg/kg/day) were used. Calcein fluorochrome at 21 days and alizarin red fluorochrome at 49 days were injected in rats (both 20 mg/kg). The animals were submitted to euthanasia 67 days after treatment, and then the right maxilla was removed for laser confocal microscopy analysis and the left maxilla for histological analysis. RESULTS: This study showed a greater calcium marking in normotensive animals treated with losartan in relation to the other groups. Laser confocal microscopy parameters showed higher values of bone volume formed, mineralized surface, active surface of mineralization and bone formation rate in normotensive animals treated with losartan. However, a smaller mineralized surface was observed in all hypertensive animals. CONCLUSION: Losartan can improve bone mineralization parameters under normal physiological conditions, but the same anabolic effect does not occur under hypertension.

Strategy of Mandibular Central Arch Reconstruction After Firearm Injury.

Gunshot wounds can cause extensive destruction of soft tissue and bone, and the maxillofacial region is often affected. The reconstructive treatment is complex due to the difficulty to reestablish the central arch mandibular contour and volume. Moreover, the goal is to avoid postoperative infections and obtain bone graft neovascularization. Therefore, this report shows a clinical case of a patient presenting mandibular deformity with a mandibular central arch discontinuity caused by a firearm injury. The strategy to the reconstructive treatment as performed with a condensed and stabilized particulate autogenous bone graft was essential and effectiveness. After 1 year, it was obtained a satisfactory result to the patient.

Losartan improves alveolar bone dynamics in normotensive rats but not in hypertensive rats

Abstract Hypertension is one of the main causes of premature death in the world; also, it is associated with several bone alterations. Preclinical studies have demonstrated delayed alveolar bone healing in hypertensive rats. However, losartan has been favorable for consolidation of bone grafts and reduction in active periodontitis. Therefore, losartan is suggested to be effective in bone formation stages, as well as in the synthesis of matrix proteins and mineralization. Objectives: To evaluate the alveolar bone dynamics in hypertensive rats treated with losartan by laser confocal microscopy and histological analysis. Methodology: Thirty-two rats, 16 spontaneously hypertensive rats (SHR) and 16 Wistar albinus rats, treated or not with losartan (30 mg/kg/day) were used. Calcein fluorochrome at 21 days and alizarin red fluorochrome at 49 days were injected in rats (both 20 mg/kg). The animals were submitted to euthanasia 67 days after treatment, and then the right maxilla was removed for laser confocal microscopy analysis and the left maxilla for histological analysis. Results: This study showed a greater calcium marking in normotensive animals treated with losartan in relation to the other groups. Laser confocal microscopy parameters showed higher values of bone volume formed, mineralized surface, active surface of mineralization and bone formation rate in normotensive animals treated with losartan. However, a smaller mineralized surface was observed in all hypertensive animals. Conclusion: Losartan can improve bone mineralization parameters under normal physiological conditions, but the same anabolic effect does not occur under hypertension.

Losartan reverses impaired osseointegration in spontaneously hypertensive rats.

OBJECTIVE: Hypertension is not only associated with cardiovascular diseases but also with alterations in bone quality. Hypertension therefore might be a risk factor for osseointegration. Preclinical studies suggest that losartan, an angiotensin II receptor blocker widely used to treat hypertension, has a beneficial effect in graft consolidation. Here, we determine the effect of hypertension and losartan on osseointegration. METHODS: We used spontaneously hypertensive rats (SHR) and normotensive Wistar albinus rats receiving losartan (30 mg/kg, p.o.) or left untreated. After 1 week, titanium miniscrews were inserted into the tibia. Sixty days after implantation, implant stability was evaluated by removal torque measurement considered the primary endpoint. Microcomputed tomography and histomorphometric analysis were secondary endpoints. RESULTS: Losartan increased the removal torque in the hypertensive SHR group to levels of the Wistar controls. While the cortical parameters of osseointegration remained unchanged, losartan increased medullary bone formation. Microcomputed tomography revealed a higher bone volume per tissue volume and trabecular thickness in the SHR rats treated with losartan. Histomorphometric analysis further showed that losartan significantly increased the thickness of newly formed bone in medullary area in hypertensive SHR rats. Losartan did not significantly alter the parameters of osseointegration in normotensive rats. CONCLUSIONS: The data presented suggest that the angiotensin II receptor antagonist losartan increases the medullary parameters of osseointegration in a tibia model of spontaneously hypertensive rats. Considering the study limitations, understanding the impact of hypertension and the respective drugs on osseointegration requires further research.

Upper Airway Obstruction in a Panfacial Fracture.

Panfacial fractures are considered the most aggressive and complex facial fracture, and most of them are the results of a high energy trauma. Therefore, a clinical report of a male patient with a panfacial fracture and Richards type 3 fracture resulting in an airway obstruction is presented. This type of fracture can promote an upper airway obstruction, which needs a correct and fast diagnosis to the life support of the patient.

Orbital Emphysema: A Rare Postoperative Complication.

Orbital emphysema can be a rare and severe postoperative complication. Fast and critical diagnosis is essential to avoid permanent visual loss to the patient. Therefore, a case of a male patient victim of a motorcycle accident with a postoperative complication of orbital emphysema has been presented. The immediate diagnosis and treatment of the orbital emphysema revealed to be the main success factors for the resolution of this complication.

Immediate Treatment of Complex Mandible Fracture in a Pediatric Patient.

The facial fractures in pediatric patients are rare, and they can need an immediate treatment to recover the function and aesthetic to the young patients. However, the open reduction internal fixation is controversial in pediatrics; it can be effectiveness to treat complex mandible fractures. Therefore, we present a case of a pediatric patient with a complex mandible fracture caused by an auto accident. The immediate treatment was successful with the use of open reduction internal fixation.

Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis.

INTRODUCTION: Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. OBJECTIVES: The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis. MATERIAL AND METHODS: Thirty animals (Rattus norvegicus, Albinus Wistar) were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG), receptor activator of nuclear kappa B ligand (RANKL) and tartrate resistant acid phosphate (TRAP) was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2), osteocalcin (OC), osteopontin (OPN), osterix (OST) and receptor activator of nuclear kappa B (RANK) were performed to determine the expression of these proteins in the alveolar bone healing. RESULTS: Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. CONCLUSION: Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic multicellular units during the alveolar bone healing.