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This research investigates the application of plastic fiber reinforcement in pre-tensioned reinforced concrete railway sleepers, conducting an in-depth examination in both experimental and computational aspects. Utilizing 3-point bending tests and the GOM ARAMIS system for Digital Image Correlation, this study meticulously evaluates the structural responses and crack development in conventional and plastic fiber-reinforced sleepers under varying bending moments. Complementing these tests, the investigation employs ABAQUS' advanced finite element modeling to enhance the analysis, ensuring precise calibration and validation of the numerical models. This dual approach comprehensively explains the mechanical behavior differences and stresses within the examined structures. The incorporation of plastic fibers not only demonstrates a significant improvement in mechanical strength and crack resistance but paves the way for advancements in railway sleeper technology. By shedding light on the enhanced durability and performance of reinforced concrete structures, this study makes a significant contribution to civil engineering materials science, highlighting the potential for innovative material applications in the construction industry.
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During secondary alveolar cleft grafting, the use of autogenous cancellous bone harvested from the iliac crest is still considered the gold standard. Due to the risk of donor-site morbidity and excessive graft resorption, alternative grafting materials (e.g. intraoral bone, xenografts) have been tested. Autogenous tooth bone graft (ATB) is a novel material derived from extracted teeth. ATB has successfully been used in pre-prosthetic and periodontal surgery for hard-tissue reconstruction. Seven patients with unilateral cleft lip and palate were treated with ATB, using their own deciduous teeth for grafting. Defects were accessed utilizing a novel split-thickness papilla curtain flap. Cone-beam computed tomography scans were taken prior to and 3 months following cleft surgery to assess graft integration, graft stability, and the volume of the newly formed hard tissues. Hard-tissue gain, as measured at the 3-month follow-up, averaged 0.65 cm3 ± 0.26 cm3. Results showed acceptable graft integration and stability at the 3-month follow-up, with no adverse effects or excessive resorption of the graft. The use of ATB might be a feasible alternative for alveolar cleft grafting. However, long-term studies using a large sample size are required to derive further conclusions.
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Injerto de Hueso Alveolar , Labio Leporino , Fisura del Paladar , Humanos , Fisura del Paladar/cirugía , Labio Leporino/cirugía , Estudios Retrospectivos , Injerto de Hueso Alveolar/métodos , Trasplante Óseo/métodosRESUMEN
Meningitis caused by Listeria monocytogenes is a rare disease in immunocompetent individuals, however, in the presence of certain risk factors with clinical signs indicating infection of the central nervous system it should not be ignored. In this case report, we present the medical history of a 72-year-old man, suffering from hypertension and liver cirrhosis, who was diagnosed with meningitis caused by L. monocytogenes. The patient was admitted to our Department with the symptoms of weakness, dizziness, high fever and urinary incontinence. Laboratory tests showed elevated inflammatory and liver enzyme values as well as low white blood cell and platelet counts were confirmed. Imaging tests did not prove any abnormalities. Due to septic parameters, after microbiological samples were collected, empiric ceftriaxon and metronidazol treatment was started. Despite our therapeutic efforts, the condition of the patient had not improved significantly. The patient still suffered from high fever; increasing agitation and tremor, coordination disorder appeared, raising the possibility of a bacterial infection of the central nervous system. Examination of the cerebrospinal fluid confirmed the diagnosis of bacterial meningitis. In the meantime, findings of microbiological cultures verified the infection of L. monocytogenes, however, cerebrospinal fluid culture did not detect any pathogen. Following that, the therapy continued with targeted ampicillin which resulted in rapid improvement of the patient's condition; fevers and neurological symptoms have ceased to exist. We considered the case worthy of presentation because of the pitfalls of the diagnosis, the emerging differential diagnostic difficulties and the favorable outcome due to the effectiveness of targeted antibiotic treatment. Orv Hetil. 2023; 164(36): 1437-1441.
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Meningitis por Listeria , Masculino , Humanos , Anciano , Meningitis por Listeria/diagnóstico , Meningitis por Listeria/tratamiento farmacológico , Ampicilina/uso terapéutico , Ceftriaxona , Fiebre/etiología , HospitalizaciónRESUMEN
OBJECTIVES: To investigate the intraosseous arterial pathways and anastomoses in the alveolar aspects of the maxilla in order to better understand the arterial scattering pattern. MATERIALS AND METHODS: Eleven cadavers were selected for macroscopic intraosseous arterial analyses by corrosion casting. The red-colored acrylic resin was injected into the external carotid arteries. The specimens were kept in an enzymatic solution at 36 °C for about 60 days, depending on the process progression. After removal of the soft tissues and drying, the bone was macerated by potassium hydroxide to analyze the course and the mean diameters of the intraosseous anastomoses. RESULTS: Vertico-oblique and horizontal intraosseous arteries and anastomoses between the greater palatine-, posterior superior alveolar-, and infraorbital arteries were detected. The vertico-oblique anastomoses were found on the anterolateral wall of the maxilla and the alveolar crest with a mean diameter of 0.46 mm; nevertheless, the horizontal (transalveolar) anastomoses were identified in the interdental septum/alveolar crest with the mean diameter of 0.41 mm. From the horizontal anastomoses, small intraseptal branches supplied the territory of the alveolar socket in various directions. CONCLUSIONS: The localization of intraosseous arterial anastomoses is critical in implant-related surgeries, predominantly to maintain proper circulation. CLINICAL RELEVANCE: Based on vertico-oblique and transalveolar anastomoses, simultaneous buccal- and palatal flap elevation (particularly on the palatal side) should be avoided to minimize patient morbidity and intra- or postoperative complications. Moreover, preserving transverse loops in the interdental septum is essential during implant surgeries, which can significantly influence collateral periosteal and osteal circulation to prevent ischemia.
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Implantes Dentales , Maxilar , Humanos , Maxilar/cirugía , Maxilar/irrigación sanguínea , Arterias , CadáverRESUMEN
BACKGROUND: Ridge resorption following tooth extraction may be reduced by alveolar ridge preservation (ARP). Previous randomized clinical trials and systematic reviews have suggested that autogenous tooth bone graft (ATB) can be an effective alternative material for ARP. However, the results are heterogeneous. Therefore, our research aimed to evaluate the efficacy of ATB in ARP. METHODS: A systematic search was conducted in Cochrane Library, Embase, MEDLINE and Scopus for studies published from inception to 31 November 2021. We searched searched for randomized, non-randomized controlled trials and case series reporting on ATB use for ARP. The primary outcome was the ridge width difference pre- and post-surgery, measured in millimetres (mm) measured on CBCT (cone beam computed tomography). The secondary outcomes were the histological results. We followed the PRISMA2020 recommendations for reporting our systematic review and meta-analysis. RESULTS: The analysis included eight studies for the primary and six for the secondary outcomes. The meta-analysis revealed a positive ridge preservation effect with a pooled mean difference ridge width change of -0.72 mm. The pooled mean residual graft proportion was 11.61%, and the newly formed bone proportion was 40.23%. The pooled mean of newly formed bone proportion was higher in the group where ATB originated from both the root and crown of the tooth. CONCLUSIONS: ATB is an effective particulate graft material in ARP. Complete demineralization of the ATB tends to decrease the proportion of newly formed bone. ATB can be an attractive option for ARP. TRIAL REGISTRATION: The study protocol was registered on PROSPERO (CRD42021287890).
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Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Humanos , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/cirugía , Alveolo Dental/cirugía , Aumento de la Cresta Alveolar/métodos , Extracción Dental/efectos adversos , Extracción Dental/métodos , Osteogénesis , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/etiología , Pérdida de Hueso Alveolar/prevención & controlRESUMEN
OBJECTIVES: To analyze morphological, volumetric, and linear hard tissue changes following horizontal ridge augmentation using a three-dimensional radiographic method. METHODS: As part of a larger ongoing prospective study, 10 lower lateral surgical sites were selected for evaluation. Horizontal ridge deficiencies were treated with guided bone regeneration (GBR) using a split-thickness flap design and a resorbable collagen barrier membrane. Following the segmentation of baseline and 6-month follow-up cone-beam computed tomography scans, volumetric, linear, and morphological hard tissue changes and the efficacy of the augmentation were assessed (expressed by the volume-to-surface ratio). RESULTS: Volumetric hard tissue gain averaged 605.32 ± 380.68 mm3. An average of 238.48 ± 127.82 mm3 hard tissue loss was also detected at the lingual aspect of the surgical area. Horizontal hard tissue gain averaged 3.00 ± 1.45 mm. Midcrestal vertical hard tissue loss averaged 1.18 ± 0.81 mm. The volume-to-surface ratio averaged 1.19 ± 0.52 mm3/mm2. The three-dimensional analysis showed slight lingual or crestal hard tissue resorption in all cases. In certain instances, the greatest extent of hard tissue gain was observed 2-3 mm apical to the initial level of the marginal crest. CONCLUSIONS: With the applied method, previously unreported aspects of hard tissue changes following horizontal GBR could be examined. Midcrestal bone resorption was demonstrated, most likely caused by increased osteoclast activity following the elevation of the periosteum. The volume-to-surface ratio expressed the efficacy of the procedure independent of the size of the surgical area.
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Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Regeneración Ósea , Humanos , Aumento de la Cresta Alveolar/métodos , Trasplante Óseo/métodos , Implantación Dental Endoósea/métodos , Estudios Prospectivos , Colgajos QuirúrgicosRESUMEN
OBJECTIVES: The aim of this study was to evaluate the effects of membrane exposure during vertical ridge augmentation (VRA) utilizing guided bone regeneration with a dense polytetrafluoroethylene (d-PTFE) membrane and a tent-pole space maintaining approach by registering radiographic volumetric, linear and morphological changes. METHODS: In 8 cases alveolar ridge defects were accessed utilizing a split-thickness flap design. Following flap elevation VRA was performed with tent-pole space maintaining approach utilizing the combination of a non-reinforced d-PTFE membrane and a composite graft (1:1 ratio of autogenous bone chips and bovine derived xenografts). Three-dimensional radiographic evaluation of hard tissue changes was carried out with the sequence of cone-beam computed tomography (CBCT) image segmentation, spatial registration and 3D subtraction analysis. RESULTS: Class I or class II membrane exposure was observed in four cases. Average hard tissue gain was found to be 0.70 cm3 ± 0.31 cm3 and 0.82 cm3 ± 0.40 cm3 with and without membrane exposure resulting in a 17% difference. Vertical hard tissue gain averaged 4.06 mm ± 0.56 mm and 3.55 mm ± 0.43 mm in case of submerged and open healing, respectively. Difference in this regard was 14% between the two groups. Horizontal ridge width at 9-month follow-up was 5.89 mm ± 0.51 mm and 5.61 mm ± 1.21 mm with and without a membrane exposure respectively, resulting in a 5% difference. CONCLUSIONS: With the help of the currently reported 3D radiographic evaluation method, it can be concluded that exposure of the new-generation d-PTFE membrane had less negative impact on clinical results compared to literature data reporting on expanded polytetrafluoroethylene membranes.
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Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Humanos , Bovinos , Animales , Aumento de la Cresta Alveolar/métodos , Politetrafluoroetileno/uso terapéutico , Regeneración Tisular Guiada Periodontal/métodos , Membranas Artificiales , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/cirugía , Pérdida de Hueso Alveolar/tratamiento farmacológico , Proceso Alveolar/cirugía , Trasplante Óseo/métodos , Implantación Dental Endoósea/métodosRESUMEN
Nowadays, the most commonly used fixation systems are non-resorbable, but new resorbable magnesium alloy fixation screws have been introduced recently. Therefore, the aim of this study was to compare the magnesium fixation screw and the commonly used non-resorbable titanium screw in an animal model. Four 3-wall defect sites were covered with collagen membranes in the mandible of twenty beagle dogs (two sites on the left and two on the right). Each membrane was fixed with either four magnesium screws or four titanium screws. Post-operative follow-up revealed the expected observations such as transient inflammation and pain. Both groups showed a good healing response, with no differences between groups. Micro-CT analysis showed no significant difference between groups in terms of BV/TV or soft tissue volume. The void volume in the magnesium fixation screw group continued to decrease on average between the different timepoints, but not significantly. Furthermore, a gradual progression of the degradation process of the magnesium screws was observed in the same group. Magnesium screws and titanium screws showed equal performance in tissue regeneration according to GBR principles. An additional advantage of magnesium screws is their resorbable nature, which eliminates the need for a second surgical step to remove the screws.
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For the surgical technique of guided bone regeneration (GBR), the choice of available barrier membranes has until recently not included an option that is mechanically strong, durable, synthetic and resorbable. The most commonly used resorbable membranes are made from collagen, which are restricted in their mechanical strength. The purpose of this study is to evaluate the degradation and regeneration potential of a magnesium membrane compared to a collagen membrane. In eighteen beagle dogs, experimental bone defects were filled with bovine xenograft and covered with either a magnesium membrane or collagen membrane. The health status of the animals was regularly monitored and recorded. Following sacrifice, the hemimandibles were prepared for micro-CT (µ-CT) analysis. Complications during healing were observed in both groups, but ultimately, the regenerative outcome was similar between groups. The µ-CT parameters showed comparable results in both groups in terms of new bone formation at all four time points. In addition, the µ-CT analysis showed that the greatest degradation of the magnesium membranes occurred between 1 and 8 weeks and continued until week 16. The proportion of new bone within the defect site was similar for both treatment groups, indicating the potential for the magnesium membrane to be used as a viable alternative to collagen membranes. Overall, the new magnesium membrane is a functional and safe membrane for the treatment of defects according to the principles of GBR.
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OBJECTIVES: The present randomized controlled clinical study aimed to investigate if, in lateral maxillary sinus augmentation, the repositioned bony wall or the application of a collagen membrane results in more preferable new hard tissue formation. MATERIALS AND METHODS: Forty patients were divided into two study groups. Both groups received a xenogeneic bone substitute material (BSM) during lateral sinus augmentation. In the bony wall group (BW), following piezosurgery, the retrieved bony wall was repositioned. In the collagen membrane group (CM), following rotary instrument preparation, collagen membrane coverage was applied. After 6 months, biopsies were taken to histologically analyze the percentage of BSM, connective tissue (CT), and newly formed bone (NFB) following both approaches. RESULTS: Forty implants were placed and 29 harvested biopsies could be evaluated. Duration of surgery, membrane perforations, and VAS were detected. Histomorphometrical analysis revealed comparable amounts of all analyzed parameters in both groups in descending order: CT (BW: 39.2 ± 9%, CM: 37,9 ± 8.5%) > BSM (BW: 32.9 ± 6.3%, CM: 31.8 ± 8.8%) > NB (BW: 27.8 ± 11.2%, CM: 30.3 ± 4.5%). CONCLUSIONS: The results of the present study show that the closure of the access window by means of the retrieved bony wall or a native collagen membrane led to comparable bone augmentation results. CLINICAL TRIAL: clinicaltrials.gov NCT04811768. CLINICAL RELEVANCE: Lateral maxillary sinus augmentation with the application of a xenogeneic BSM in combination with a native collagen membrane for bony window coverage represents a reliable method for surgical reconstruction of the posterior maxilla. Piezosurgery with bony window repositioning delivers comparable outcomes without membrane coverage.
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Sustitutos de Huesos , Elevación del Piso del Seno Maxilar , Senos Transversos , Regeneración Ósea , Colágeno , Implantación Dental Endoósea/métodos , Humanos , Maxilar/patología , Maxilar/cirugía , Seno Maxilar/patología , Seno Maxilar/cirugía , Estudios Prospectivos , Elevación del Piso del Seno Maxilar/métodos , Senos Transversos/cirugíaRESUMEN
Barrier membranes are commonly used as part of the dental surgical technique guided bone regeneration (GBR) and are often made of resorbable collagen or non-resorbable materials such as PTFE. While collagen membranes do not provide sufficient mechanical protection of the covered bone defect, titanium reinforced membranes and non-resorbable membranes need to be removed in a second surgery. Thus, biodegradable GBR membranes made of pure magnesium might be an alternative. In this study a biodegradable pure magnesium (99.95%) membrane has been proven to have all of the necessary requirements for an optimal regenerative outcome from both a mechanical and biological perspective. After implantation, the magnesium membrane separates the regenerating bone from the overlying, faster proliferating soft tissue. During the initial healing period, the membrane maintained a barrier function and space provision, whilst retaining the positioning of the bone graft material within the defect space. As the magnesium metal corroded, it formed a salty corrosion layer and local gas cavities, both of which extended the functional lifespan of the membrane barrier capabilities. During the resorption of the magnesium metal and magnesium salts, it was observed that the membrane became surrounded and then replaced by new bone. After the membrane had completely resorbed, only healthy tissue remained. The in vivo performance study demonstrated that the magnesium membrane has a comparable healing response and tissue regeneration to that of a resorbable collagen membrane. Overall, the magnesium membrane demonstrated all of the ideal qualities for a barrier membrane used in GBR treatment.
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An ideal fixation system for guided bone (GBR) regeneration in oral surgery must fulfil several criteria that includes the provision of adequate mechanical fixation, complete resorption when no longer needed, complete replacement by bone, as well as be biocompatible and have a good clinical manageability. For the first time, a biodegradable magnesium fixation screw made of the magnesium alloy WZM211 with a MgF2 coating has been designed and tested to fulfill these criteria. Adequate mechanical fixation was shown for the magnesium fixation screw in several benchtop tests that directly compared the magnesium fixation screw with an equivalent polymeric resorbable device. Results demonstrated slightly superior mechanical properties of the magnesium device in comparison to the polymeric device even after 4 weeks of degradation. Biocompatibility of the magnesium fixation screw was demonstrated in several in vitro and in vivo tests. Degradation of the magnesium screw was investigated in in vitro and in vivo tests, where it was found that the screw is resorbed slowly and completely after 52 weeks, providing adequate fixation in the early critical healing phase. Overall, the magnesium fixation screw demonstrates all of the key properties required for an ideal fixation screw of membranes used in guided bone regeneration (GBR) surgeries.
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OBJECTIVE: The aim of the current article was to present a radiographic method to determine the surface area of newly formed periodontal attachment, as well as to analyze volumetric and morphologic changes after regenerative periodontal treatment. METHOD AND MATERIALS: In this retrospective study, 11 singular intrabony periodontal defects were selected for minimally invasive surgical treatment and 3D evaluation. 3D virtual models were acquired by the segmentation of pre- and postoperative CBCT scans. This study determined the surface area of baseline periodontal attachment (RSA-A) and defect-involved root surface (RSA-D) on the preoperative 3D models, and the surface area of new periodontal attachment (RSA-NA) on the postoperative models. Finally, cumulative change of periodontal attachment (∆RSA-A) was calculated and Boolean subtraction was applied on pre- and postoperative 3D models to demonstrate postoperative 3D hard tissue alterations. RESULTS: The average RSA-A was 84.39 ± 33.27 mm2, while the average RSA-D was 24.26 ± 11.94 mm2. The average surface area of RSA-NA after regenerative periodontal surgery was 17.68 ± 10.56 mm2. Additionally, ∆RSA-A was determined to assess the overall effects of ridge alterations on periodontal attachment, averaging 15.53 ± 12.47 mm2, which was found to be statistically significant (P = .00149). Lastly, the volumetric hard tissue gain was found to be 33.56 ± 19.35 mm3, whereas hard tissue resorption of 26.31 ± 38.39 mm3 occurred. CONCLUSION: The proposed 3D radiographic method provides a detailed understanding of new periodontal attachment formation and hard tissue alterations following regenerative surgical treatment of intrabony periodontal defects.
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Pérdida de Hueso Alveolar , Enfermedades Periodontales , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/cirugía , Estudios de Seguimiento , Regeneración Tisular Guiada Periodontal/métodos , Humanos , Pérdida de la Inserción Periodontal/diagnóstico por imagen , Pérdida de la Inserción Periodontal/cirugía , Enfermedades Periodontales/cirugía , Bolsa Periodontal/cirugía , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVES: To compare the accuracy of implant placement performed with either a surgical motor or a torque wrench as part of a half-guided surgical protocol. MATERIALS AND METHODS: Implant insertion with half-guided surgical protocol was utilized by surgical motor (machine-driven group) or torque wrench (manual group) in the posterior maxilla. After the healing period, accuracy comparison between planned and actual implant positions was performed based on preoperative cone beam computed tomography and postoperative digital intraoral scans. Coronal, apical, and angular deviations, insertion time, and insertion torque were evaluated. RESULTS: Forty patients were treated with 1 implant each; 20 implants were inserted with a surgical motor and 20 implants with a torque wrench. Global coronal and apical deviations were 1.20 ± 0.46 mm and 1.45 ± 0.79 mm in the machine-driven group, and 1.13 ± 0.38 mm and 1.18 ± 0.28 mm in the manual group (respectively). The mean angular deviation was 4.82 ± 2.07° in the machine-driven group and 4.11 ± 1.63° in the manual group. Mean insertion torque was 21.75 ± 9.75 Ncm in the machine-driven group, compared to 18.75 ± 7.05 Ncm in the manual group. Implant placement duration was 9.25 ± 1.86 s in the machine-driven group at a speed of 50 rpm, and 36.40 ± 8.15 s in the manual group. CONCLUSION: No significant difference was found between the two groups in terms of accuracy and mean insertion torque, while machine-driven implant placement was significantly less time-consuming. CLINICAL RELEVANCE: Optimal implant placement accuracy utilized by half-guided surgical protocol can be achieved with both machine-driven and torque wrench insertion. TRIAL REGISTRATION: ID: NCT04854239.
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Implantes Dentales , Cirugía Asistida por Computador , Tomografía Computarizada de Haz Cónico , Implantación Dental Endoósea , Humanos , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Estudios ProspectivosRESUMEN
AIM: The purpose of this article is to present a novel method for the CBCT subtraction analysis of 3D changes following alveolar ridge preservation (ARP) with the application of a semi-automatic segmentation workflow and spatial registration. The study hypothesis was that by utilizing our novel approach, better 3D visualization and improved volumetric and linear evaluations of alveolar reconstructive procedures could be achieved following ARP compared with existing methodologies. MATERIALS AND METHODS: Ten surgical sites of 10 partially edentulous patients were treated with a tunneled guided bone regeneration approach for ARP. Spatial registration and a semi-automatic segmentation method were utilized to create 3D digital models of pre- and postoperative CBCT datasets for subtraction analysis. The primary outcome variable of the study was the volumetric difference between pre- and postoperative CBCT scans. Secondary outcome variables were horizontal and vertical linear measurements at the mesial, distal, and middle aspects of the alveolus. RESULTS: Change of hard tissue volume averaged at 0.34 ± 0.99 cm3. The mean change of vertical hard tissue dimension was 5.97 ± 3.18 mm at the mesial, 6.40 ± 3.03 mm at the distal, and 7.01 ± 3.02 mm at the middle aspect of the extraction sites. Horizontal linear changes averaged at 6.19 ± 0.68 mm at the mesial, 6.32 ± 1.52 mm at the distal, and 6.90 ± 1.48 mm at the middle aspects of the extraction sites. CONCLUSION: The digital reconstruction of CBCT datasets with the presented approach may provide a better understanding of the healing mechanisms following ARP. Not only the direct effect on extraction socket healing, but also the indirect positive effect on adjacent teeth can be visualized.
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Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Tomografía Computarizada de Haz Cónico Espiral , Pérdida de Hueso Alveolar/diagnóstico por imagen , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/cirugía , Estudios de Seguimiento , Humanos , Extracción Dental , Alveolo Dental/cirugíaRESUMEN
Virtual, hybrid three-dimensional (3D) model acquisition is presented in this article, utilizing the sequence of radiographic image segmentation, spatial registration, and free-form surface modeling. Firstly cone-beam computed tomography datasets were reconstructed with a semi-automatic segmentation method. Alveolar bone and teeth are separated into different segments, allowing 3D morphology, and localization of periodontal intrabony defects to be assessed. The severity, extent, and morphology of acute and chronic alveolar ridge defects are validated concerning adjacent teeth. On virtual complex tissue models, positions of dental implants can be planned in 3D. Utilizing spatial registration of IOS and CBCT data and subsequent free-form surface modeling, realistic 3D hybrid models can be acquired, visualizing alveolar bone, teeth, and soft tissues. With the superimposition of IOS and CBCT soft tissue, thickness above the edentulous ridge can be assessed about the underlying bone dimensions; therefore, flap design and surgical flap management can be determined, and occasional complications may be avoided.
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Tomografía Computarizada de Haz Cónico , Imagenología TridimensionalRESUMEN
BACKGROUND: The active arterial-to-arterial collaterals are a significant factor in the prevention of ischemia and extensive tissue necrosis in the case of arterial blockage of various tissues. The present study investigates the mucogingival vasculature in the maxillary esthetic zone mucosa in human cadavers and functionally evaluates the area, which is supplied by the terminal arterioles, on the individual level. METHODS: In the human cadaver study, macroscopic arterial analyses of the anterior maxillary vestibule in 7 specimens were scrutinized by latex milk injection. The tracks of the mucosal branches in relation to the mucogingival junction were investigated. In the functional study, individual gingival blood flow (GBF) changes were measured by laser speckle contrast imaging (LSCI) in 31 young subjects with healthy gingiva before and during 30-s compressions. This was conducted with a ball-shaped condenser. The data was analyzed by the linear mixed model. RESULTS: The vertically aligned branches of the superior labial artery (SLA) divided into small, slightly deviating sub-branches near the mucogingival junction. These arteries created collateral plexuses and supplied the attached gingiva. The compression of these branches resulted in ischemia coronally with significant individual variation. The ischemia was either apico-mesial, apico-distal, or straight apical to the compression. A significant correlation was found between the ischemic area and the magnitude of the decrease in GBF (r = 0.81, p < 0.001). In males, 77% of the subjects, and 50% of the female subjects had an ischemic response in either region. The horizontal extension of the ischemic area ranged between 0.26 mm and 8.76 mm. Males had significantly higher baseline GBF and larger ischemia than females. At the base of the papilla, significant restoration of GBF was observed during compression in males, but not in females. CONCLUSION: The arcade anastomoses formed by the small arteries in the keratinized gingiva of the upper esthetic zone explain the consequences of vertical incisions. The considerable individual variations in ischemic responses might be the reason for unexpected surgical outcomes in some cases. Furthermore, there is increasing evidence that men have different vascular reactivity and/or regulation of collateral circulation than women, which may affect wound healing.
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Encía , Cicatrización de Heridas , Estética , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: The shrinkage of alveolar bone dimensions after tooth extraction is a well-known issue. This clinical phenomenon poses a challenge for clinicians aiming at implant-prosthetic treatment. BonMaker® ATB is a novel autogenous bone grafting material, produced by the mechanical and chemical processing of natural teeth. This pilot case report aims at providing a clinical, radiographical, and histological evaluation of the safety and efficacy of Bonmaker ATB powder in the treatment of EDS class 3-4 postextraction sockets with alveolar ridge preservation. METHODS: A total of 9 teeth were extracted from 5 patients. The extracted teeth were prepared immediately with the Bonmaker® device. The extraction sockets were filled up with ATB powder. Six months after extraction, standardized intraoral x-rays and CBCT scans were performed. Re-entry was performed under local anaesthesia. Core biopsies were harvested for histological analysis and implants were placed. RESULTS: Horizontal alveolar dimension loss occurred, even though ARP was performed, but the horizontal shrinkage was moderate. Vertical dimensions did not show loss of volume, but increased defect fill. Core biopsies showed ATB particles surrounded by newly formed bone and connective tissue. According to histomorphometric analysis, the harvested samples contained 56% of newly formed bone on average, and only a mean of 7% of non-remodelled ATB material was observed. CONCLUSION: The preliminary clinical, radiographical, and histological results of Bonmaker® autogenous tooth graft therapy indicate that ATB may be safely and successfully used as a grafting material for ARP. Optimal graft incorporation and histologically proven effective remodelling, as well as uneventful wound healing support the clinical application of ATB to minimize post-extraction hard tissue loss. Further research is needed to exploit the full potential of ATB and to evaluate the long-term peri-implant hard and soft tissue stability of ATB-treated post-extraction sites.
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Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/cirugía , Trasplante Óseo , Humanos , Minerales , Extracción Dental , Alveolo Dental/diagnóstico por imagen , Alveolo Dental/cirugíaRESUMEN
OBJECTIVES: Currently, empirical clinical findings on the blood supply of the maxillary vestibule are not backed up with sufficient literature. The purpose of this study was to investigate the mucosal and periosteal vascular supply in the maxillary vestibule macroscopically and radiographically to improve surgical strategies and flap designs. MATERIALS AND METHODS: Thirty head corpses were selected (9 dentate, 11 partially edentulous, 10 edentulous). Twenty-six corpses were injected by red latex milk and embalmed with Thiel solution. Four cadavers were prepared for corrosion casting. Arterial path and anastomoses in the maxillary vestibule of dentate, partially edentulous and edentulous ridges, were analyzed macroscopically and by computed tomography (CT). RESULTS: Transverse periosteomucosal anastomoses were detected in the posterior and esthetic zones of the maxillary vestibule. The buccal branches penetrated the interdental septum toward the palate. In the esthetic zone, superior labial artery (SLA) supplied the mucosa and the infraorbital artery (IOA) supplied the periosteum. Corrosion casting showed anastomoses between IOA and nasal septal branches. CT analysis revealed ipsilateral and contralateral anastomoses between SLA and IOA. In dentate ridges, mucosal star-shaped terminal branches were detected. CONCLUSIONS: The macroscopic and radiographic vascular survey analysis revealed the anatomical background behind several clinically documented phenomena related to oral and periodontal surgeries. CLINICAL RELEVANCE: This study permits clinicians to design less invasive flaps when releasing incisions in the maxillary vestibule during periodontal and implant surgeries. Our observations strongly point to the significance of an undamaged periosteum to prevent compromised flap revascularization and wound healing disturbances.