RESUMO

Horizontal bone augmentation is a common surgical procedure used in implant therapy to achieve adequate bone volume to permit dental implant placement. However, most current techniques are focused on unidirectional bone reconstruction (grafting only on the buccal side). This study was carried out to validate a new device that will permit bidirectional bone augmentation. Ten patients of both sexes (7 women and 3 men), with ages ranging from 29 to 62 years, who needed a bidirectional horizontal bone augmentation in maxilla were separated in accordance with the horizontal alveolar change (HAC) classification published by Pelegrine et al (2018). The patients classified as HAC 3 (ie, containing remaining cancellous bone at the recipient bed) received the Barbell device with xenogeneic biomaterial and a collagen membrane, whereas HAC 4 patients (ie, with no remaining cancellous bone at the recipient bed) received the Barbell device with a mixture of autogenous bone chips and xenogeneic biomaterial covered by a collagen membrane. For each patient, two computerized tomography scans were performed (T0 at baseline and T1 at 6 months postoperative examinations). Mean bone thickness (T0) in the studied sites were 3.25 ± 0.35 in HAC 3 and 1.98 ± 0.5 in HAC 4 patients. The mean bone thickness achieved after 6 months was 7.70 ± 0.89 mm and 8.62 ± 0.89 in HAC 3 and 4, respectively. All grafted sites were able to receive dental implants in adequate prosthetic positions. Based on these results, the use of this novel device permits bidirectional horizontal bone augmentation.

Assuntos

Aumento do Rebordo Alveolar , Implantes Dentários , Masculino , Humanos , Feminino , Implantação Dentária Endóssea , Aumento do Rebordo Alveolar/métodos , Transplante Ósseo/métodos , Tomografia Computadorizada por Raios X , Colágeno/uso terapêutico , Materiais Biocompatíveis

RESUMO

The aim of this study was to compare the clinical, tomographic, and histological performance of collagenated xenogeneic bone blocks (CXBB) in horizontal bone augmentations for implant placement. Five patients with an absence of the 4 upper incisors and an HAC 3 horizontal bone defect, with a remaining of 3 to 5 mm, underwent a bone-grafting procedure with CXBB (test group [TG], n = 5) and autogenous graft (control group [CG], n = 5), with one type of graft used on the right side and other type on the left side. Changes in bone thickness and density (tomographic evaluation), levels of complications (clinically), and distribution pattern between mineralized and nonmineralized tissue (histomorphometrically) were analyzed. Tomographic analysis showed a horizontal bone increase of 4.25 ± 0.78 mm in the TG and 3.08 ± 0.8 mm in the CG between baseline and 8 months postoperatively (P < .05). The horizontal loss between the day of installation of the blocks and 8 months postoperatively was 1.02 ± 0.39 mm for the TG and 1.10 ± 0.71 mm for the CG (P > .05). With regard to bone density, the TG blocks right after installation had 440.2 ± 89.15 HU, and after 8 months, the region reached 730.7 ± 130.98 HU, representing an increase of 29.05%. For the CG blocks, bone density increased from 1052.2 ± 398.35 HU to 1222.5 ± 453.28 HU, representing an increase of 17.03%. The increase in bone density was significantly higher in the TG (P < .05). Clinically, no cases of exposure of the bone blocks and no failure of incorporation were observed. Histomorphometrically, the percentage of mineralized tissue was lower in the TG than in the CG (48.10% ± 2.88% and 53.53% ± 1.05%, respectively), and the opposite was verified for the levels of nonmineralized tissue (52.79% ± 2.88% and 46.47% ± 1.05%, respectively; P < .05). The use of CXBB achieved higher levels of horizontal gain, with lower bone density and lower levels of mineralized tissue when compared with the use of autogenous blocks.

Assuntos

Aumento do Rebordo Alveolar , Implantação Dentária Endóssea , Humanos , Implantação Dentária Endóssea/métodos , Projetos Piloto , Estudos Prospectivos , Aumento do Rebordo Alveolar/métodos , Boca , Transplante Ósseo/métodos

RESUMO

BACKGROUND: The vertical increase of the alveolar ridge dimension using allograft or xenograft mixed with autogenous bone graft and covered by a nonabsorbable high-density polytetrafluoroethylene (d-PTFE) membrane is well documented in the literature. PURPOSE: The aim of this study was to assess vital mineralized tissue formation in vertical ridge augmentation (VRA) procedures using autogenous bone chips mixed either with an allograft or a xenograft. METHODS: This prospective clinical trial recruited 16 partially edentulous patients to undergo vertical ridge augmentation in one or more sites, making up a total of 24 samples for histological evaluation. Patients were sequentially stratified into Group A (treated with a freeze-dried bone allograft [FDBA] mixed with autogenous bone) or to Group B (treated with a bovine xenograft mixed with autogenous bone). Histological samples were analyzed according to the biomaterial used for VRA. Histological samples were obtained on the same day of membrane removal and implant placement. RESULTS: Thirty-three implants were placed in 16 sites of regenerated bone via VRA, 13 patients with ridge augmentation in the posterior mandible, and 3 patients with VRA in the anterior maxilla. Group A (FDBA + autogenous) and Group B (xenograft + autogenous) showed a percent vital mineralized tissue (VMT) area of 67.64 ± 16.84 and 60.93 ± 18.25, respectively. A significant difference between the two biomaterials was not observed. CONCLUSION: When mixed with autogenous bone, either allografts or xenografts may provide a successful augmentation. Either mixture could serve as reliable alternative in VRA for obtaining a high percentage of VMT.

Assuntos

Aumento do Rebordo Alveolar , Aumento do Rebordo Alveolar/métodos , Animais , Materiais Biocompatíveis/uso terapêutico , Transplante Ósseo/métodos , Bovinos , Implantação Dentária Endóssea/métodos , Humanos , Membranas Artificiais , Politetrafluoretileno

RESUMO

BACKGROUND: Implant installation with conventional drilling can create buccal bone defects in areas of limited ridge thickness. Implant installation with osseodensification may aid in preventing buccal bone defects in these situations. This in vitro pilot study evaluated the impact of osseodensification on the increase in alveolar ridge thickness and the prevention of buccal peri-implant defects. METHODS: Ten fresh pig mandibles with limited bone thickness were selected for use in an experimental randomized split mouth pilot study. Two site-preparation protocols were used: conventional drilling with cutting burs (CTL, n = 10) and osseodensification with Densah® burs (OD, n = 10). After implant bed preparation, 20 implants (4.5 × 10 mm) were placed in the prepared sites and the insertion torque was recorded. Clinical and photographic analysis evaluated ridge thickness and the extent (height, width, and area) of bone defects in the buccal and lingual bone walls following implant placement. Three-dimensional measurements were performed using STL files to analyze the increase in buccal ridge thickness following site preparation and implant placement. The height of the buccal bone defect was considered as the primary outcome of this study. Defect width, area, implant insertion torque, and linear buccal ridge increase after implant site preparation and installation were also assessed. Non-parametric evaluations were carried out with the Mann-Whitney test to verify intergroup differences. RESULTS: There was no statistically significant difference between groups in the baseline ridge thickness. OD presented a significantly higher insertion torque, associated with reduced buccal and lingual bone defect width, in comparison to CTL. CONCLUSIONS: The increase in buccal ridge thickness after site preparation and implant placement was significantly higher in OD compared to CTL. Osseodensification increased the ridge thickness through expansion and reduced buccal bone defects after implant installation.

Assuntos

Aumento do Rebordo Alveolar , Implantes Dentários , Processo Alveolar/cirurgia , Aumento do Rebordo Alveolar/métodos , Animais , Implantação Dentária Endóssea/métodos , Humanos , Boca , Projetos Piloto , Suínos

RESUMO

AIMS: To estimate the change in the alveolar ridge by means of a new alveolar ridge preservation (ARP) approach, using an anodized titanium foil (Tseal) associated with a bovine bone graft (BBG) by cone-beam computerized tomography. MATERIALS AND METHODS: Sixteen patients, each presenting one hopeless tooth, were selected and these teeth were carefully extracted. The alveolar socket was filled with BBG and the Tseal was trimmed and adapted to the bone crest. The primary outcome variable was the change in the alveolar dimension (AD) measurements between baseline (T1) and 6 months (T2) 1mm below the palatal bone. RESULTS: Imaging assessment of AD demonstrated a decreased value in all subjects. The absolute rate and percentage of absorption between T1 and T2 time point showed statistically significant differences. The mean AD varied from 9.88 ± 2.04 mm (T1) to 8.85 ± 1.92 mm (T2). On average, this ARP procedure maintained 89.55% ± 6.11% of the distance of between the buccal and palatal wall. No differences were observed between the maxilla and mandible (p greater than 0.05). CONCLUSION: The application of a bovine bone graft covered with Tseal resulted in clinically important horizontal preservation of the alveolar ridge at 6 months after extraction.

Assuntos

Perda do Osso Alveolar , Aumento do Rebordo Alveolar , Perda do Osso Alveolar/diagnóstico por imagem , Processo Alveolar/diagnóstico por imagem , Animais , Bovinos , Humanos , Estudos Prospectivos , Titânio , Extração Dentária , Alvéolo Dental/cirurgia

RESUMO

(1) Background: This study aimed to evaluate the incorporation of hydroxyapatite/ß-tricalcium phosphate blocks grafted in rabbit mandibles. (2) Methods: Topographic characterization of biomaterial was performed through scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). Ten rabbits randomly received autogenous bone graft harvested from the tibia (Autogenous Group-AG) or synthetic biomaterial manufactured in ß-tricalcium phosphate (Biomaterial Group-BG) at their right and left mandibular angles. Euthanasia was performed at 30 and 60 postoperative days; (3) Results: SEM-EDX showed a surface with the formation of crystals clusters. Histological analyses in BG at 30 days showed a slower process of incorporation than AG. At 60 days, BG showed remnants of biomaterial enveloped by bone tissue in the anabolic modeling phase. Histometric analysis showed that mean values of newly formed bone-like tissue in the AG (6.56%/9.70%) were statistically higher compared to BG (3.14%/6.43%) in both periods, respectively. Immunohistochemical analysis demonstrated early bone formation and maturation in the AG with more intense osteopontin and osteocalcin staining. (4) Conclusions: The biomaterial proved to be a possible bone substitute, being incorporated into the receiving bed; however, it showed delayed bone incorporation compared to autogenous bone.

RESUMO

Los aumentos óseos previo a la instalación de implantes son cada vez mas utilizados y el diseño de nuevas estrategias para disminuir la morbilidad deben ser considerados. El objetivo de esta investigación fue definir el aumento óseo generado con la técnica "tent pole" en sector de mandíbula posterior. Se diseño un estudio longitudinal, prospectivo para estudiar la técnica. Se incluyeron sujetos con ancho óseo no mayor a 4 mm en el sector posterior y con altura no menor a 9 mm desde el margen superior del conducto alveolar inferior. Se realizaron cirugías bajo anestesia local realizando un acceso quirúrgico; se instalaron de 2 a 4 tornillos de osteosíntesis manteniendo 4 mm del tornillo extraóseo para luego reconstruir con biomaterial alógeno y L-PRF en conjunto con una membrana biológica absorbible; después de 4 meses se realizaron las re entradas estableciendo con tomografía computadorizada de haz cónico las ganancias óseas generadas. Fueron operados 14 sujetos con 27 sitios quirúrgicos; en todos los casos se pudo realizar la instalación de implantes a los 4 meses. En la evaluación inicial, el ancho óseo observado estaba entre 1,2 y 4,0 mm (promedio de 2,95 ± 0,75 mm); después de 4 meses de realizado el aumento horizontal el ancho observado fue de 3,79 y 10,05 mm (promedio de 7,15 mm ± 1,87 mm), confirmando una ganancia ósea promedio de 4,2 ± 1,26 mm. La diferencia obtenida fue significativa (p< 0,05). Se puede concluir que la técnica "tent pole" aplicada en esta investigación es predecible en el aumento óseo y aplicable para la rehabilitación sobre implante.

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Bone augmentation prior to implant placement, is among strategies that should be considered to reduce morbidity rates in these procedures. The objective of this research was to define bone augmentation generator using the "tent pole " technique in the posterior jaw. A longitudinal, prospective study was designed, and subjects were included with ridge width no greater than 4 mm, height no less than 9 mm from the upper margin of the inferior alveolar canal. Surgeries were performed under local anesthesia for surgical approach; 2 to 4 osteosynthesis screws over ridge with 4 mm of the extra osseous screws were installed and were then regenerated, using allogeneic biomaterial and L-PRF together with an absorbable biological membrane. Re-entry was performed after four months and cone beam computed tomography analysis was used to confirm bone gain. Fourteen subjects were operated with 27 surgical sites; in all the cases, implant installation was possible at 4 months. In the initial evaluation, bone width observed was between 1.2 and 4.0 mm (average of 2.95 ± 0.75 mm); after 4 months of the horizontal increase, width was recorded at 3.79 and 10.05 mm (average of 7.15 mm ± 1.87 mm), confirming an average bone increase of 4.2 ± 1.26 mm. The difference obtained was significant (p <0.05). It can be concluded that the "tent pole" technique applied in this analysis is predictable in bone augmentation and applicable for implant rehabilitation.

Assuntos

Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Implantação Dentária Endóssea/métodos , Aumento do Rebordo Alveolar , Mandíbula/cirurgia , Estudos Prospectivos , Estudos Longitudinais , Transplante Ósseo , Substitutos Ósseos , Tomografia Computadorizada de Feixe Cônico

RESUMO

STUDY DESIGN: Systematic review. OBJECTIVES: To assess the efficacy of kyphoplasty in controlling pain and improving quality of life in oncologic patients with metastatic spinal disease and pathologic compression fractures of the spine. METHODS: A literature search through medical database was conducted (using PubMed, EMBASE, Cochrane, and LILACS) for randomized controlled trials comparing balloon kyphoplasty versus the traditional treatment for compression fractures of the spine due to metastatic disease. Two investigators independently assessed all titles and abstracts to select potential articles to be included. Inclusion criteria consisted of randomized controlled trials involving patients with pathologic compression fractures due to spinal metastasis or multiple myeloma treated with balloon kyphoplasty procedure as one of the study interventions, while the control group was any other treatment modality. The risk of bias in individual studies was assessed. RESULTS: Two studies, with a combined total of 181 patients, met inclusion criteria. Because of data heterogeneity, the meta-analysis was not possible, and individual analysis of studies was performed. There is moderate evidence that patients treated with balloon kyphoplasty displayed better scores for pain (Numeric Rating Scale), disability (Roland-Morris Disability Questionnaire), quality of life (Short Form-36 Health Survey), and functional status (Karnofsky Performance Status) compared with those undergoing the conventional treatment. Patients treated with kyphoplasty also have better recovery of vertebral height. CONCLUSIONS: This study concluded that balloon kyphoplasty could be considered as an early treatment option for patients with symptomatic neoplastic spinal disease, although further randomized clinical trials should be performed for improvement of the quality of evidence.

RESUMO

The use of short implants as an alternative to bone reconstruction techniques for the placement of standard-length dental implants is a debated topic. The aim of this study was to perform a systematic review and meta-analysis in order to assist in the clinical decision making about the most appropriate approach for the fixed rehabilitation of the posterior atrophic partially edentulous lower jaws. Only randomized trials with at least 1-year follow-up were included. Of the 1024 studies initially retrieved, 14 articles were selected and independently evaluated by two reviewers. Finally, four studies were included, and underwent data extraction and meta-analysis with the Bayesian approach. Both treatment approaches provide high implant survival rate after 1year of function. However, the probability of survival rate of short implants being greater than standard length implants is 84%, and the probability of complications using short implants being greater than standard-length implants is 15.7%. In spite of similar survival rates when the residual bone is sufficient for placement of short implants, the latter should be preferred to augmentation techniques and standard-length implants due to fewer complications, lower morbidity and greater comfort for patients.

Assuntos

Perda do Osso Alveolar/cirurgia , Aumento do Rebordo Alveolar/métodos , Teorema de Bayes , Implantes Dentários , Planejamento de Prótese Dentária , Arcada Parcialmente Edêntula/cirurgia , Mandíbula/patologia , Mandíbula/cirurgia , Reconstrução Mandibular/métodos , Atrofia , Falha de Restauração Dentária , Humanos , Complicações Pós-Operatórias , Ensaios Clínicos Controlados Aleatórios como Assunto

RESUMO

Cr-Co-Mo (ASTM F75) alloy has been used in the medical environment, but its use as a rigid barrier membrane for supporting bone augmentation therapies has not been extensively investigated. In the present study, Cr-Co-Mo membranes of different heights were placed in New Zealand white, male rabbit tibiae to assess the quality and volume of new bone formation, without the use of additional factors. Animals were euthanized at 20, 30, 40, and 60 days. Bone formation was observed in all of the cases, although the tibiae implanted with the standard membranes reached an augmentation of bone volume that agreed with the density values over the timecourse. In all cases, plasmatic exudate was found under the membrane and in contact with the new bone. Histological analysis indicated the presence of a large number of chondroblasts adjacent to the inner membrane surface in the first stages, and osteoblasts and osteocytes were observed under them. The bone formation was appositional. The Cr-Co-Mo alloy provides a scaffold with an adequate microenvironment for vertical bone volume augmentation, and the physical dimensions and disposition of the membrane itself influence the new bone formation.

RESUMO

Calcium phosphates and bioactive glass ceramics have been considered promising biomaterials for use in surgeries. However, their moldability should be further enhanced. We here thereby report the handling, physicochemical features, and morphological characteristics of formulations consisting of carboxymethylcellulose-glycerol and hydroxyapatite-tricalcium phosphate or Biosilicate® particles. We hypothesized that combining either material with carboxymethylcellulose-glycerol would improve handling properties, retaining their bioactivity. In addition to scanning electron microscopy, cohesion, mineralization, pH, and viscoelastic properties of the novel formulations, cell culture experiments were performed to evaluate the cytotoxicity and cell proliferation. Putty-like formulations were obtained with improved cohesion and moldability. Remarkably, mineralization in simulated body fluid of hydroxyapatite-tricalcium phosphate/carboxymethylcellulose-glycerol formulations was enhanced compared to pure hydroxyapatite-tricalcium phosphate. Cell experiments showed that all formulations were noncytotoxic and that HA-TCP60 and BGC50 extracts led to an increased cell proliferation. We conclude that combining carboxymethylcellulose-glycerol with either hydroxyapatite-tricalcium phosphate or Biosilicate® allows for the generation of moldable putties, improves handling properties, and retains the ceramic bioactivity.

Assuntos

Substitutos Ósseos/química , Fosfatos de Cálcio/química , Carboximetilcelulose Sódica/análogos & derivados , Durapatita/química , Vidro/química , Glicerol/química , Animais , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Elasticidade , Camundongos , Viscosidade

RESUMO

The present study reviewed the literature regarding dental implants in HIV-infected patients and reports the long-term follow-up of three clinical cases of patients under HAART that received bone augmentation and dental implants. The first case presents a young patient with a large defect in the mandible, as a consequence of a longitudinal fracture, that was treated with guided bone regeneration (GBR) previously to implant placement. The second case reported is middle-aged man with a fractured upper lateral incisor treated with immediate placement and simultaneous GBR to repair the dehiscence due to the buccal bone resorption. The third case shows an elderly patient that underwent sinus lifting with the simultaneous placement of two implants. All cases were treated after patients were medically controlled and followed for at least 10 years. Controlled HIV-infected patients undergoing HAART may be candidates to implant rehabilitation, as long as their plasmatic HIV viral load and CD4+ T lymphocytes count are within the parameters that indicate immune stability. Long-term stability of soft and hard tissues can be obtained maintaining function and esthetics. However, stronger evidence, based on prospective, controlled clinical trials is needed to provide the dental and medical teams with conclusive data.

Assuntos

Aumento do Rebordo Alveolar , Terapia Antirretroviral de Alta Atividade , Implantes Dentários , Infecções por HIV/tratamento farmacológico , Adulto , Reabsorção Óssea/cirurgia , Estética Dentária , Feminino , Regeneração Tecidual Guiada , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas dos Dentes/cirurgia

RESUMO

BACKGROUND: Severe alveolar atrophy often presents a challenge for the implant surgery. The significant lack of bone in the alveolar ridges may compromise the final restorations both from the aesthetic and functional standpoints. OBJECTIVES: To evaluate the behavior of bone block allografts for the maxillary augmentation and to investigate its incorporation, remodeling, and implant survival rates in two different healing time points. MATERIAL AND METHODS: Sixty-six consecutive patients (52 female/14 male, mean age: 57.95 ± 9.06 years old), presenting 113 atrophic alveolar ridges underwent maxillary augmentation with fresh-frozen allogeneic bone blocks from tibia. Patients were randomly assigned in two groups: Group 1-patients who would wait 4 months for implant placement after grafting, and Group 2-patients who would wait 6 months. Events of infection, suture dehiscence or mucosal perforation were recorded. Cone-beam computed tomography scans were compared volumetrically between the time of the grafting surgery and reentry procedure after incorporation. Biopsies were collected and subjected to histological, histomorphometric and immunehistochemical analysis. RESULTS: A total of 305 implants were placed in the reconstructed sites. The mean resorption rate in Group 1 (13.98% ± 5.59) was significantly lower than Group 2 (31.52% ± 6.31). The amount of calcified tissue, newly formed bone and remaining graft particles demonstrated no difference between groups. The samples showed evident immunolabeling for the podoplanin protein in both groups. The implants cumulative survival rate was 94.76%. CONCLUSIONS: The findings of the present study indicate that there is a significant difference regarding the resorption of the grafts when waiting 4 or 6 months before placing the implants, even though no difference was found in the histological, histomorphometric, and immunohistochemical features. Both 4-month and 6-months healing times are suitable for the implant placement.

Assuntos

Perda do Osso Alveolar/cirurgia , Remodelação Óssea/fisiologia , Transplante Ósseo/métodos , Implantação Dentária Endóssea/métodos , Maxila/cirurgia , Boca Edêntula/cirurgia , Osseointegração/fisiologia , Levantamento do Assoalho do Seio Maxilar/métodos , Adulto , Idoso , Perda do Osso Alveolar/patologia , Reabsorção Óssea , Tomografia Computadorizada de Feixe Cônico , Prótese Dentária Fixada por Implante/métodos , Feminino , Humanos , Imageamento Tridimensional , Masculino , Maxila/patologia , Maxila/fisiopatologia , Pessoa de Meia-Idade , Boca Edêntula/fisiopatologia , Osteócitos/patologia , Fatores de Tempo

RESUMO

BACKGROUND: The success of bone augmentation to a major degree depends on the biomechanics and biological conditions of the surrounding tissues. Therefore, an animal model is needed providing anatomical sites with similar mechanical pressures for comparing its influence on different biomaterials for bone regeneration. The present report describes the new bone formation associated to biomaterial in a bursa created in the epidural space, between dura mater and cranial calvaria, under the constant pressure of cerebrospinal fluid. METHODS: Five adult California rabbits were used for the trial. In each animal, two bursae were created in the epidural spaces, in the anterior part of the skull, below both sides of the interfrontal suture. The spaces between dura mater and cranial calvaria were filled with in-situ hardening biphasic calcium phosphate containing hydroxyapatite and beta tricalcium-phosphate (BCP), in-situ hardening phase-pure beta-tricalcium phosphate (ß-TCP) or without any biomaterials (sham). After 90 days, the animals were sacrificed, and the defect sites were extracted and processed for histomorphometric analysis by optical and backscattered electron microscopy. RESULTS: The cranial epidural spaces created (n = 10) could be preserved by the application both BCP (n = 3) and ß-TCP biomaterials (n = 3) in all experimental sites. The sites augmented with BCP showed less new bone formation but a trend to better volume preservation than the sites augmented with ß-TCP. However, the bone in the BCP sites seemed to be more mature as indicated by the higher percentage of lamellar bone in the sites. In contrast, the created space could not be preserved, and new bone formation was scarce in the sham-operated sites (n = 4). CONCLUSION: The experimental bursae created bilaterally in the epidural space allows comparing objectively bone formation in relation to biomaterials for bone regeneration under permanent physiological forces from cerebrospinal fluid pressure.

Assuntos

Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/farmacologia , Osteogênese/fisiologia , Animais , Regeneração Óssea/fisiologia , Transplante Ósseo/métodos , Fosfatos de Cálcio/farmacologia , Modelos Animais de Doenças , Espaço Epidural/cirurgia , Hidroxiapatitas/farmacologia , Imuno-Histoquímica , Coelhos , Distribuição Aleatória , Sensibilidade e Especificidade , Crânio/cirurgia

RESUMO

BACKGROUND: Supplementation of bone substitutes with recombinant platelet-derived growth factor-BB (PDGF-BB) can enhance bone regeneration. The aim of the study was to evaluate the effect of PDGF-BB on bone formation in the presence of ß-tricalcium phosphate and bovine bone mineral matrix in a rat calvaria defect model. METHODS: The authors examined 5 mm rat calvarial defects treated with ß-tricalcium phosphate (TCP) or demineralized bovine bone mineral (DBBM) with and without 0.3 mg/ml recombinant PDGF-BB. Calvaria defects were randomly divided into the following treatment groups (n = 5); TCP; TCP plus PDGF-BB; DBBM; DBBM plus PDGF-BB; and untreated empty control. After 45 days, bone formation was evaluated by histomorphometry and fluorescence microscopy. RESULTS: The authors report that the area of newly formed bone was similar between the empty controls and the two bone substitutes, TCP and DBBM. Supplementation of TCP and DBBM with PDGF-BB had no significant impact on bone formation. Fluorochrome staining revealed no visible changes in the pattern of bone formation in defects filled with TCP and DBBM, irrespective of PDGF-BB. Furthermore, supplementation with PDGF-BB did not influence biomaterial degradation. CONCLUSIONS: The authors concluded that PDGF-BB had no impact on bone formation and degradation of bone substitutes in the respective rodent models. Thus, possible beneficial effects of PDGF-BB may require other model situations.

Assuntos

Fosfatos de Cálcio/farmacologia , Osteogênese , Animais , Substitutos Ósseos , Bovinos , Minerais , Projetos Piloto , Ratos

RESUMO

OBJECTIVE: The aim of this paper is to report a clinical case of nasal floor elevation and simultaneous dental implant placement. CASE REPORT: The patient presented to the clinic of the Center of Education and Research on Dental Implants (CEPID) in the Department of Dentistry at the Federal University of Santa Catarina (UFSC, Florianópolis, Brazil), for follow-up for peri-implantitis control. After clinical and radiographic assessment, two of three implants on anterior maxilla were removed. A cone beam computed tomography (CBCT) scan revealed no bone height for conventional length implant insertion. Nasal floor elevation and simultaneous implant placement were performed, with nasal cavity augmentation carried out with bovine bone graft. After six months, the implants were reopened successfully. CONCLUSIONS: Nasal floor elevation proved to be a reliable method for dental implants insertion on the anterior atrophic maxilla when bone height reconstruction was necessary. The use of bovine bone substitutes for nasal cavity augmentation showed predictable results as well as simultaneous implant placement.

RESUMO

We have evaluated the effect of the use of platelet-rich plasma in alveolar distraction osteogenesis. Fourteen patients who were partly edentulous in the anterior premaxilla region were selected and randomised into two groups (n=7 in each group). Those in the experimental group were give platelet-rich plasma at the time of distraction, and the control group had only distraction. Selected cases had defects in the alveolar ridge of more than 3mm, and a minimal bone height of 7 mm from the alveolar ridge crest to important anatomical structures. The plaque index and gingival index were recorded on days 3, 7, 14, 21, 28, 45, 60, 75, 90, and 105 postoperatively. There was a strong negative correlation between the gingival index and augmentation of bone, and a strong positive correlation between the mean gingival index and loss of bone from the transported segment. The addition of platelet-rich plasma had a protective effect on the mucosa around the distractor, which decreased the potential for complications.

Assuntos

Osteogênese por Distração , Processo Alveolar , Aumento do Rebordo Alveolar , Implantação Dentária Endóssea , Humanos , Plasma Rico em Plaquetas

RESUMO

OBJECTIVE: To study osseointegration of implants with surface modifications by the use of fluoroboric acid and/or H2 O2 installed in conventional sites or sites with circumferential marginal defects. MATERIAL AND METHODS: Four implants with different surfaces were used. One basic surface (ZirTi(®)) was sandblasted with zirconium microspheres and acid etched additionally with hydrofluoric acid. A second surface was treated with fluoroboric acid instead of hydrofluoric acid. The remainder of the other two surfaces was additionally treated with H2O2. The edentulous mandibles of 6 foxhound dogs were used to randomly install 8.5-mm-long implants with the different surfaces and to study the histological healing after 1 and 3 months. To study osteoconductivity, additional four recipient sites were prepared with the coronal region being widened so that a 4 mm deep and 0.85 mm wide marginal defect resulted after the placement of the four implants with different surfaces. No filler material or membranes were used, and a fully submerged healing was allowed for 3 months. RESULTS: At the conventional sites, new bone formation ranged between 68.5% and 74.9% after 1 month. After 3 months, bone-to-implant contact ranged from 72.6% at the ZirTi(®) surface to 84.1% at the fluoroboric acid-treated implants, the difference being statistically significant. At the sites with marginal defects, bone formation ranged from 0.77 mm at the surface treated with fluoroboric acid and H2O2 , to 1.93 mm at the surface treated with fluoroboric acid alone. CONCLUSIONS: Fluoroboric acid treatment alone of titanium implant surfaces resulted in improved osseointegration and osteoconductivity after 3 months.

Assuntos

Implantação Dentária Endóssea/métodos , Implantes Dentários , Osseointegração/fisiologia , Cicatrização/fisiologia , Condicionamento Ácido do Dente , Animais , Boratos , Planejamento de Prótese Dentária , Cães , Mandíbula/cirurgia , Teste de Materiais , Distribuição Aleatória , Propriedades de Superfície , Titânio , Zircônio

RESUMO

BACKGROUND: Insufficient residual alveolar bone height is a common deterrent in the placement of dental implants in the posterior maxilla. The use of autografts, xenografts, allografts and alloplasts or a combination between them has been demonstrated to be effective for increasing bone height and bone volume in the deficient posterior maxilla. PURPOSE: The aim of this clinical trial is to comparatively determine the density of newly formed in sinus floor augmentation bone after a 24-week healing period treatment with a new bovine xenograft. MATERIALS AND METHODS: The sinus floor was grafted with Bio-Oss® (n = 10) and Osseous® (n = 10). Histological sections were examined with a focus on the presence of connective tissue (CT) and newly formed bone (NFB). The sections were histomorphometrically evaluated and the definitive crown was inserted after 3 months. RESULTS: After 6 months, the mean value of new bone formation was 24.60 (±2.503), the CT was 42.60 (±4.006) and the remaining biomaterial was 25.40 (±2.547) in Bio-Oss group. In Osseous group, the mean value of new bone formation was 24.90 (±3.542), the CT was 45.70 (±7.040) and the remaining biomaterial was 22.90 (±3.247). CONCLUSIONS: Both biomaterials afforded a favorable implant position and the prosthetic rehabilitation.

Assuntos

Substitutos Ósseos/uso terapêutico , Minerais/uso terapêutico , Levantamento do Assoalho do Seio Maxilar/métodos , Adulto , Idoso , Animais , Bovinos , Implantação Dentária Endóssea/métodos , Feminino , Xenoenxertos/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade

RESUMO

BACKGROUND: Bone augmentation is a subject of intensive investigation in regenerative bone medicine and constitutes a clinical situation in which autogenous bone grafts or synthetic materials are used to aid new bone formation. METHOD: Based on a non-critical defect, Co-Cr barrier membranes were placed on six adult Fauve de Bourgogne rabbits, divided into two groups: whole blood and PRP. Three densitometric controls were performed during the experiment. The animals were euthanized at 30, 45, 60, and 110 days. The presence of newly formed bone was observed. Samples for histological studies were taken from the augmentation center. RESULTS: External and internal bone tissue augmentation was observed in almost all cases. Significant differences between PRP- and whole blood-stimulated bone augmentation were not observed. At 60 days, bones with PRP presented higher angiogenesis, which may indicate more proliferation and cellular activity. CONCLUSION: PRP activates the bone regeneration process under optimized conditions by stimulation of osteoblast proliferation after six weeks, when a significant difference in cellular activity was observed. Membranes could stimulate bone augmentation at the site of placement and in the surrounding areas.