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1.
J Maxillofac Oral Surg ; 22(3): 559-570, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37534349

ABSTRACT

Objective: A specific type of mesenchymal stem/progenitor cells (MSPCs), CD105+ is reported to aid in cartilage regeneration through TGF-ß/Smad2-signalling. The purpose of this study was to identify and characterize CD105+ MSPCs in temporomandibular joint (TMJ) cartilage. Materials and Methods: MSPCs were isolated from mouse TMJ condyle explants and evaluated for their clonogenicity and pluripotential abilities. MSPC were examined for CD105 antigen using immunohistochemistry and flow cytometry. Results: Immunohistochemistry revealed presence of CD105+ MSPCs in the proliferative zone of condyle's cartilage. Only 0.2% of isolated MSPCs exhibited CD105, along with the stem cell surface markers CD44 and Sca-1. In CD105+ MSPCs, intracellular immunostaining revealed significantly higher (p < 0.05) protein levels of collagen type 1, 2, proteoglycan 4. Ability for chondrogenic differentiation was found to be significantly higher (p < 0.05) after 4 weeks compared to CD105- cells, using alcian blue staining. CD105+ cells were found to resemble an early MSPC subgroup with significantly higher gene expression of biglycan, proteoglycan 4, collagen type 2, Gli2, Sox5 (p < 0.001) and Sox9 (p < 0.05). In contrast, significantly lower levels of Runx2 (p < 0.05), Osterix, Trps1, Col10a1 (p < 0.01), Ihh (p < 0.001) related to chondrocyte senescence and commitment to osteogenic lineage, were observed compared to CD105- cells. Conclusion: The study showed the existence of a CD105+ MSPC subgroup within TMJ fibrocartilage that may be activated to aid in fibrocartilage repair.

2.
J Biomech Eng ; 145(9)2023 09 01.
Article in English | MEDLINE | ID: mdl-37195691

ABSTRACT

Short dental implants with platform matching connection have been used for the rehabilitation of atrophic jaws whenever standard-length dental implants cannot be placed without prior bone augmentation. Yet, there remains a lack of data regarding the risk of technical failures when the all-on-4 configuration is performed in atrophic jaws with platform-switching distal short dental implants. Thus, the current study used the finite element method to evaluate the mechanical behavior at the level of the prosthetic components of the all-on-4 concept performed in atrophic mandible using short-length distal implants with platform switching (PSW) connection. Three models of the all-on-4 configuration were generated in human atrophic mandibles. The geometric models consisted of PSW connection tilted standard (AO4T; θ = 30 deg; 11 mm-length), straight standard (AO4S; θ = 0 deg; 11 mm-length) and straight short (AO4Sh; θ = 0 deg; 8 mm-length) distal implants. A resultant force of 300 N was performed obliquely in the left side and posterior region of the prosthetic bar. The von Mises equivalent stress (σvm) and maximum and minimum principal stresses (σmax and σmin) were performed at level of the prosthetic components/implants and peri-implant bone crest, respectively. The general displacement of the models was also evaluated. The stress analysis was performed on the side of load application. The AO4S configuration showed the lowest values of σvm in the mesial left (ML) and distal left (DL) abutments (37.53 MPa and 232.77 MPa, respectively) and dental implants (91.53 MPa and 231.21 MPa, respectively). The AO4Sh configuration showed the highest values of σvm in the bar screw (102.36 MPa), abutment (117.56 MPa), and dental implant (293.73 MPa) of the ML area. Among the models, the highest values of σmax and σmin were noticed in the peri-implant bone crest of the AO4T design (131.48 MPa and 195.31 MPa, respectively). All models showed similar values of general displacements, which were concentrated in the mandible symphysis. The all-on-4 configurations designed with PSW connection and tilted standard (AO4T; θ = 30 deg; 11 mm-length), straight standard (AO4S; θ = 0 deg; 11 mm-length) or straight short (AO4Sh; θ = 0 deg; 8 mm-length) distal implants were not associated with higher odds of technical failures. The AO4Sh design may be a promising option for the prosthetic rehabilitation of atrophic jaws.


Subject(s)
Dental Implants , Humans , Stress, Mechanical , Finite Element Analysis , Mandible/surgery , Dental Stress Analysis
3.
J Stomatol Oral Maxillofac Surg ; 124(6): 101479, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37080358

ABSTRACT

Recent studies have shown that bisphosphonates can also impact osteoblasts besides osteoclasts. This study aimed to evaluate the effects of different concentrations of Zoledronic acid (ZA) during the osteogenic differentiation of human Bone Marrow Stem Cells (hBMSCs) in vitro. Thus, osteogenic differentiation of hBMSCs was conducted with different concentrations of Zoledronic Acid (ZA) (0, 0.1, 1.0, and 5.0 µM) for the first 3 days. Cell metabolism was quantified at 1-, 3-, 7-, and 14 days. At 7- and 14-days, the following analyses were performed: 1) mineralization nodule assay, 2) LIVE/DEAD™, 3) cell adhesion and spreading, 4) alkaline phosphatase (ALP) activity, and 5) qPCR analysis for RUNX-2), ALPL, and COL1 A1. Data were analyzed by ANOVA 2-way, followed by Tukey's post hoc test (p < 0.05). Cell metabolism (3-, 7-, and 14-days) (p < 0.001), mineralization (7-, 14-days) (p < 0.001), and ALP activity (14-days) (p < 0.001) were reduced in ZA 5.0 µM when compared to control (no ZA). Also, ZA 5.0 µM downregulated the expression of RUNX2 at 7- and 14-days (p < 0.001). It is possible to conclude that ZA (5.0 µM) can impair hBMSC differentiation into osteoblasts and interferes with its mineralization phase.


Subject(s)
Diphosphonates , Osteogenesis , Humans , Zoledronic Acid/pharmacology , Diphosphonates/pharmacology , Cell Differentiation , Bone Marrow Cells
4.
J Biomed Mater Res B Appl Biomater ; 110(12): 2686-2704, 2022 12.
Article in English | MEDLINE | ID: mdl-35779277

ABSTRACT

This study aims to evaluate the potential of a novel biomaterial synthesized from amorphous calcium phosphate (ACP), octacalcium phosphate (OCP), and hydroxyapatite (HA) to repair critical-sized defects (CSD) in rabbit calvaria. In vitro analyses of cell viability, cell proliferation, formation of mineral nodules, and cell differentiation using qPCR were performed for comparing experimental calcium phosphate (ECP), deproteinized bovine bone (DBB), and beta-tricalcium phosphate (ß-TCP). Bilateral CSDs were created in 45 rabbit calvaria. Six groups were evaluated: ECP, ECP + fibrin sealant (ECP + S), coagulum, autogenous bone, DBB, and ß-TCP. Euthanasia was performed at 2, 4, and 8 weeks, followed by micro-computed tomography and histological and immunohistochemical analyses. Results from in vitro analyses revealed similar biocompatibility for all tested materials and a tendency for higher gene expression of some bone markers in the ECP group than in ß-TCP and DBB groups at 7 days. In contrast to that in DBB and ß-TCP groups, ECP displayed growing bone volume over total volume percentage (BV/TV%) with time in vivo. Histological analysis revealed a greater number of giant cells and reduced size of grafted particles in ECP during all periods of analysis. RUNX-2 expression was statistically lower in ECP than DBB at 2 and 4 weeks. Despite no statistical significance, ECP presented the highest absolute values for ALP-expression at 2, 4, and 8 weeks compared with other groups. Together, our findings indicate that a combination of the ACP, OCP, and HA phases into ECP is beneficial and promising for bone regeneration.


Subject(s)
Bone Substitutes , Fibrin Tissue Adhesive , Animals , Biocompatible Materials , Bone Regeneration , Bone Substitutes/pharmacology , Calcium Phosphates/pharmacology , Cattle , Durapatite/pharmacology , Rabbits , Skull/pathology , X-Ray Microtomography
5.
J Stomatol Oral Maxillofac Surg ; 123(6): e777-e781, 2022 11.
Article in English | MEDLINE | ID: mdl-35772700

ABSTRACT

BACKGROUND: Implant placement is a common part of dental rehabilitation in older individuals. The role of diminished bone mineral density on the healing of dental implants remains to be elucidated. OBJECTIVE: The aim of this study was to assess the implant survival rate in postmenopausal women with osteopenia/osteoporosis. METHODS: A retrospective cohort study was conducted of postmenopausal women treated with dental implants and stratified into two groups: those receiving antiresorptive therapy (W ≥ 50 years S) or those not receiving treatment (W ≥ 50 years U). The predictor variable was osteopenia/osteoporosis treatment. The outcome variable was implant failure rate at stage two uncovering. Other study variables included: age, implant location, and bone graft placement. T-test, chi-square test, and univariate and multivariate logistic regression were computed. A p-value<0.05 was considered statistically significant. RESULTS: The sample was composed of 93 W ≥ 50 years U (197 implants) and 114 W ≥ 50 years S (189 implants). W ≥ 50 years U showed a statistically higher implant failure rate with chi-square testing compared to W ≥ 50 years S (p=0.022). However, univariate, and multivariate logistic regression between age, location, bone grafting, and implant failure did not demonstrate significant associations. CONCLUSION: Both groups integrated dental implants successfully, with a low failure rate. Implant location, bone grafting, and osteopenia/osteoporosis treatment did not significantly affect osseointegration at uncovering.


Subject(s)
Bone Diseases, Metabolic , Dental Implants , Osteoporosis , Female , Humans , Aged , Retrospective Studies , Pilot Projects , Postmenopause , Survival Rate , Bone Diseases, Metabolic/epidemiology
6.
Rev. cir. traumatol. buco-maxilo-fac ; 22(2): 19-24, abr.-jun. 2022. ilus, tab
Article in Portuguese | LILACS, BBO - Dentistry | ID: biblio-1398982

ABSTRACT

Introdução: As limitações das terapias atuais para doenças degenerativas da articulação temporomandibular (ATM) levaram ao aumento do interesse em estratégias regenerativas. A engenharia de tecidos (ET), combinando células-tronco, arcabouços e fatores de crescimento, pode fornecer uma substituição biológica funcional e permanente das estruturas da ATM, além de prevenir o avanço de doenças degenerativas. Objetivo: Este artigo descreve as perspectivas atuais da ET das estruturas da ATM em modelos animais. Metodologia: As abordagens da ET foram categorizadas de acordo com as estruturas primárias da ATM: 1) o disco articular, 2) o côndilo mandibular e 3) a fossa glenóide e eminência articular. Resultados: As áreas com a maior quantidade de estudos são o côndilo mandibular e disco articular, em estudos que abordam o uso de arcabouços tridimensionais, de origem sintética e/ou natural, podendo ou não estar associados a células tronco (diferenciadas ou não) e a fatores de crescimento. Conclusão: A ET da ATM ainda é uma área relativamente nova, em desenvolvimento e em constante avanço. Os avanços tecnológicos desenvolvidos nessa área têm o potencial de auxiliar no desenvolvimento de terapias mais eficientes e menos invasivos... (AU)


Introducción: Las limitaciones de las terapias actuales para las enfermedades degenerativas de la articulación temporomandibular (ATM) han llevado a un mayor interés en las estrategias regenerativas. La ingeniería de tejidos, que combina células, andamios y factores de crecimiento, puede proporcionar un reemplazo biológico funcional y permanente de las estructuras de la ATM, además de prevenir el avance de enfermedades degenerativas. Objetivo: Este artículo describe las perspectivas actuales de la ingeniería de tecidos de las estructuras de la ATM en modelos animales. Metodología: Los enfoques de ingeniería de tejidos se clasificaron según las estructuras primarias de la ATM: 1) el disco articular, 2) el cóndilo mandibular y 3) la fosa glenoidea y la eminencia articular. Resultados: Las áreas con mayor número de estudios son el cóndilo mandibular y el disco articular, en estudios que abordan el uso de estructuras tridimensionales, de origen sintético y/o natural, que pueden o no estar asociadas a células (diferenciadas o no) y con factores de crecimiento. Conclusión: La ingeniería de tejidos de la ATM es todavía un área relativamente nueva, en desarrollo y em constante avance. Los avances tecnológicos desarrollados en esta área tienen el potencial de ayudar en el desarrollo de terapias más eficientes y menos invasivas... (AU)


Introduction: The limitations of current therapies for degenerative diseases of the temporomandibular joint (TMJ) have led to increased interest in regenerative strategies. Tissue engineering (TE), combining stem cells, scaffolds, and growth factors, can provide a functional and permanent biological replacement of TMJ structures, in addition to preventing the advancement of degenerative diseases. Aim: This article describes current TE perspectives of TMJ structures in animal models. Methods: TE approaches were categorized according to the primary TMJ structures: 1) the articular disc, 2) the mandibular condyle, and 3) the glenoid fossa and articular eminence. Results: The areas with the greatest number of studies are the mandibular condyle and articular disc, in studies that address the use of three-dimensional scaffolds, of synthetic and/or natural origin, which may or may not be associated with stem cells (differentiated or not) and with growth factors. Conclusion: TE of the TMJ is still a relatively new, developing, and constantly advancing area. The technological advances developed in this area have the potential to assist in the development of more efficient and less invasive therapies... (AU)


Subject(s)
Humans , Male , Female , Stem Cells , Temporomandibular Joint/surgery , Tissue Engineering , Mandibular Condyle , Technological Development
7.
Rev. cir. traumatol. buco-maxilo-fac ; 22(1): 49-55, jan.-mar. 2022. ilus, tab
Article in Portuguese | LILACS, BBO - Dentistry | ID: biblio-1392234

ABSTRACT

Introdução: As limitações das terapias atuais para doenças degenerativas da articulação temporomandibular (ATM) levaram ao aumento do interesse em estratégias regenerativas. A engenharia de tecidos (ET), combinando células-tronco, arcabouços e fatores de crescimento, pode fornecer uma substituição biológica funcional e permanente das estruturas da ATM, além de prevenir o avanço de doenças degenerativas. Objetivo: Este artigo descreve as perspectivas atuais da ET das estruturas da ATM em modelos animais. Metodologia: As abordagens da ET foram categorizadas de acordo com as estruturas primárias da ATM: 1) o disco articular, 2) o côndilo mandibular e 3) a fossa glenóide e eminência articular. Resultados: As áreas com a maior quantidade de estudos são o côndilo mandibular e disco articular, em estudos que abordam o uso de arcabouços tridimensionais, de origem sintética e/ou natural, podendo ou não estar associados a células tronco (diferenciadas ou não) e a fatores de crescimento. Conclusão: A ET da ATM ainda é uma área relativamente nova, em desenvolvimento e em constante avanço. Os avanços tecnológicos desenvolvidos nessa área têm o potencial de auxiliar no desenvolvimento de terapias mais eficientes e menos invasivos... (AU)


Introducción: Las limitaciones de las terapias actuales para las enfermedades degenerativas de la articulación temporomandibular (ATM) han llevado a un mayor interés en las estrategias regenerativas. La ingeniería de tejidos, que combina células, andamios y factores de crecimiento, puede proporcionar un reemplazo biológico funcional y permanente de las estructuras de la ATM, además de prevenir el avance de enfermedades degenerativas. Objetivo: Este artículo describe las perspectivas actuales de la ingeniería de tecidos de las estructuras de la ATM en modelos animales. Metodología: Los enfoques de ingeniería de tejidos se clasificaron según las estructuras primarias de la ATM: 1) el disco articular, 2) el cóndilo mandibular y 3) la fosa glenoidea y la eminencia articular. Resultados: Las áreas con mayor número de estudios son el cóndilo mandibular y el disco articular, en estudios que abordan el uso de estructuras tridimensionales, de origen sintético y/o natural, que pueden o no estar asociadas a células (diferenciadas o no) y con factores de crecimiento. Conclusión: La ingeniería de tejidos de la ATM es todavía un área relativamente nueva, en desarrollo y en constante avance. Los avances tecnológicos desarrollados en esta área tienen el potencial de ayudar en el desarrollo de terapias más eficientes y menos invasivas... (AU)


Introduction: The limitations of current therapies for degenerative diseases of the temporomandibular joint (TMJ) have led to increased interest in regenerative strategies. Tissue engineering (TE), combining stem cells, scaffolds, and growth factors, can provide a functional and permanent biological replacement of TMJ structures, in addition to preventing the advancement of degenerative diseases. Aim: This article describes current TE perspectives of TMJ structures in animal models. Methods: TE approaches were categorized according to the primary TMJ structures: 1) the articular disc, 2) the mandibular condyle, and 3) the glenoid fossa and articular eminence. Results: The areas with the greatest number of studies are the mandibular condyle and articular disc, in studies that address the use of three-dimensional scaffolds, of synthetic and/ or natural origin, which may or may not be associated with stem cells (differentiated or not) and with growth factors. Conclusion: TE of the TMJ is still a relatively new, developing, and constantly advancing area. The technological advances developed in this area have the potential to assist in the development of more efficient and less invasive therapies... (AU)


Subject(s)
Animals , Stem Cells , Temporomandibular Joint , Cells , Models, Animal , Tissue Engineering , Intercellular Signaling Peptides and Proteins , Growth and Development , Biological Products , Technological Development , Mandibular Condyle
8.
Clin Oral Investig ; 26(2): 1477-1489, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34386857

ABSTRACT

OBJECTIVE: To assess the interaction between chemotherapy and normal tissues is critical to assure quality of life during and after the treatment of cancer. This study evaluated the influence of cisplatin (CIS) and 5-fluorouracil (5-FU) over the peri-implant tissues around osseointegrated titanium implants in animals previously exposed to nicotine. Materials and methods One hundred twenty male rats were divided into two groups, receiving via subcutaneous injection, either physiological saline solution (PSS) (n = 30) or nicotine hemissulfate (NIC) (n = 90) for 30 days prior to implants' placement. One titanium implant (4.0 × 2.2 mm) was installed in each tibia of all animals. PSS and NIC were continued for 30 days after surgery. Five days after cessation, rats were subdivided into three subgroups in accordance with systemic treatments with either PSS, CIS, or 5-FU. Euthanasia was performed at 50, 65, and 95 days post-surgery. Histometric, histopathological, and immunohistochemical analyses were performed. RESULTS: NIC-CIS and NIC-5FU presented lower BIC (50, 65, and 95 days) and bone area fraction occupancy (BAFO) (65 and 95 days) than group NIC. Intense inflammatory infiltration, severe tissue breakdown, reduced expression of bone formation biomarkers, and upregulation of TRAP were observed in NIC-CIS and NIC-5FU when compared with group NIC. TRAP expression was significantly higher in NIC-5FU as compared with NIC-CIS at 50 and 95 days. Groups NIC, NIC-CIS, and NIC-5FU presented statistically significant negative impact in all outcome parameters than group PSS. CONCLUSION: CIS and 5-FU severely disrupted the peri-implant tissues around osseointegrated implants in animals previously exposed to nicotine. CLINICAL RELEVANCE: Assessing the interaction between chemotherapy and normal tissues is critical to assure quality of life during and after the cancer treatment.


Subject(s)
Antineoplastic Agents , Dental Implants , Animals , Male , Nicotine , Osseointegration , Quality of Life , Rats , Tibia , Titanium
10.
Mater Sci Eng C Mater Biol Appl ; 75: 1359-1365, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-28415427

ABSTRACT

Bacterial cellulose has become established as a new biomaterial, and it can be used for medical applications. In addition, it has called attention due to the increasing interest in tissue engineering materials for wound care. In this work, the bacterial cellulose fermentation process was modified by the addition of chondroitin sulfate to the culture medium before the inoculation of the bacteria. The biomimetic process with heterogeneous calcium phosphate precipitation of biological interest was studied for the guided regeneration purposes on bacterial cellulose. FTIR results showed the incorporation of the chondroitin sulfate in the bacterial cellulose, SEM images confirmed the deposition of the calcium phosphate on the bacterial cellulose surface, XPS analysis showed a selective chemical group influences which change calcium phosphate deposition, besides, the calcium phosphate phase with different Ca/P ratios on bacterial cellulose surface influences wettability. XTT results concluded that these materials did not affect significantly in the cell viability, being non-cytotoxic. Thus, it was produced one biomaterial with the surface charge changes for calcium phosphate deposition, besides different wettability which builds new membranes for Guided Tissue Regeneration.


Subject(s)
Calcium Phosphates , Cellulose , Materials Testing , Membranes, Artificial , Polysaccharides, Bacterial , Animals , CHO Cells , Calcium Phosphates/chemistry , Calcium Phosphates/pharmacology , Cell Survival/drug effects , Cellulose/chemistry , Cellulose/pharmacology , Cricetinae , Cricetulus , Polysaccharides, Bacterial/chemistry , Polysaccharides, Bacterial/pharmacology , Surface Properties
11.
Araçatuba; s.n; 2013. 116 p. ilus, tab.
Thesis in English | LILACS, BBO - Dentistry | ID: lil-711299

ABSTRACT

Proposição: Realizar uma caracterização físico-química, morfológica e comparar o comportamento mecânico de uma liga experimental de Ti-Mo, ao sistema de fixação análogo à base de Ti, em fraturas de ângulo mandibular, favoráveis ao deslocamento. Adicionalmente, análises de elementos finitos 3D foram realizadas para avaliar o padrão de distribuição de tensões nas placas e nos parafusos. Material e Método: Vinte e oito réplicas de mandίbulas de poliuretano foram usadas e uniformemente seccionadas na região do ângulo mandibular esquerdo. Estas foram divididas em 4 grupos considerando o material das placas e as técnicas de fixação interna: grupo Eng 1P, uma placa (zona de tensão da mandίbula) e 4 parafusos de 6 mm de comprimento; grupo Eng 2P, duas placas (uma na zona de tensão da mandίbula e a outra na zona de compressão), a primeira fixada com 4 parafusos de 6 mm de comprimento e a segunda com 4 parafusos de 12 mm de comprimento, sendo todo o material de fixação do sistema 2.0-mm. Os mesmos grupos foram criados para a liga Ti-15Mo. Cada grupo foi submetido a uma carga vertical linear no primeiro molar. As médias e os desvios-padrão foram comparados para avaliação estatίstica (ANOVA; p < .05). Adicionalmente, foi construído um modelo de elementos finitos 3D considerando as mesmas variáveis para avaliar as tensões equivalentes de von Mises (σvM) nas placas e nos parafusos. Resultados: Diferença estatisticamente significativa (p < .05) foi encontrada quando foi realizada a comparação entre ambas as técnicas de fixação (1 e 2 placas), independentemente do material das placas (cpTi and Ti-15Mo). Quando considerado os valores das tensões equivalentes de von Mises (σvM) para a comparação entre ambos os grupos (Eng and Ti-15Mo) com 1 placa, verificou-se uma redução de 10.5% na placa e de 29.0% nos parafusos, para o grupo da liga titânio-molibdênio. Ainda, quando foi realizada a comparação dos mesmos grupos com 2 placas, o fator mais relevante foi uma redução, na...


Purpose: Perform a physico-chemical and morphological characterization and compare the mechanical behavior of an experimental Ti-Mo alloy to the analogous metallic Ti-based fixation system, for mandibular angle fractures, favorable to displacement. Additionally, finite element analysis was performed to assess the stress distribution in the plates and screws. Material and Method: Twenty eight polyurethane mandible replicas were used and uniformly sectioned on the left mandibular angle. These were divided into 4 groups considering the material of the plates and the internal fixation techniques: group Eng 1P, one 2.0-mm plate (tension zone of the mandible) and 4 screws 6 mm long; group Eng 2P, two 2.0-mm plates (one in the tension zone of the mandible and the other in the compression zone), the first fixed with 4 screws 6 mm long and the second with 4 screws 12 mm long. The same groups were created for the titanium alloy (Ti-15Mo). Each group was subjected to linear vertical loading at the first molar. Means and standard deviations were compared with respect to statistical significance (ANOVA; p < .05). Additionally, an three-dimensional finite element model reproducing the characteristics of the specimens used in the mechanical tests were created to evaluate the von Mises equivalent stress (σvM) in the plates and screws. Results: Statistically significant difference (p < .05) was found when the comparison between both internal fixation techniques (1 and 2 plates) was performed, regardless the materials of the plates (cpTi and Ti-15Mo). When considering the von Mises equivalent stress (σvM) values for the comparison between both groups (Eng and Ti-15Mo) with 1 plate, an decrease of 10.5% in the plate and an decrease of 29.0% in the screws for the titanium-molybdenum- based group was observed. Also, when comparing the same groups with 2 plates, the relevant fact was an decrease of 28.5% in the screws for the Ti- 15Mo group. Conclusion: The 2P technique showed…


Subject(s)
Bone Plates , Fracture Fixation, Internal , Mandible , Molybdenum , Titanium , Finite Element Analysis
12.
Araçatuba; s.n; 2013. 116 p. ilus, tab.
Thesis in English | LILACS, BBO - Dentistry | ID: biblio-866767

ABSTRACT

Proposição: Realizar uma caracterização físico-química, morfológica e comparar o comportamento mecânico de uma liga experimental de Ti-Mo, ao sistema de fixação análogo à base de Ti, em fraturas de ângulo mandibular, favoráveis ao deslocamento. Adicionalmente, análises de elementos finitos 3D foram realizadas para avaliar o padrão de distribuição de tensões nas placas e nos parafusos. Material e Método: Vinte e oito réplicas de mandίbulas de poliuretano foram usadas e uniformemente seccionadas na região do ângulo mandibular esquerdo. Estas foram divididas em 4 grupos considerando o material das placas e as técnicas de fixação interna: grupo Eng 1P, uma placa (zona de tensão da mandίbula) e 4 parafusos de 6 mm de comprimento; grupo Eng 2P, duas placas (uma na zona de tensão da mandίbula e a outra na zona de compressão), a primeira fixada com 4 parafusos de 6 mm de comprimento e a segunda com 4 parafusos de 12 mm de comprimento, sendo todo o material de fixação do sistema 2.0-mm. Os mesmos grupos foram criados para a liga Ti-15Mo. Cada grupo foi submetido a uma carga vertical linear no primeiro molar. As médias e os desvios-padrão foram comparados para avaliação estatίstica (ANOVA; p < .05). Adicionalmente, foi construído um modelo de elementos finitos 3D considerando as mesmas variáveis para avaliar as tensões equivalentes de von Mises (σvM) nas placas e nos parafusos. Resultados: Diferença estatisticamente significativa (p < .05) foi encontrada quando foi realizada a comparação entre ambas as técnicas de fixação (1 e 2 placas), independentemente do material das placas (cpTi and Ti-15Mo). Quando considerado os valores das tensões equivalentes de von Mises (σvM) para a comparação entre ambos os grupos (Eng and Ti-15Mo) com 1 placa, verificou-se uma redução de 10.5% na placa e de 29.0% nos parafusos, para o grupo da liga titânio-molibdênio. Ainda, quando foi realizada a comparação dos mesmos grupos com 2 placas, o fator mais relevante foi uma redução, na...


Purpose: Perform a physico-chemical and morphological characterization and compare the mechanical behavior of an experimental Ti-Mo alloy to the analogous metallic Ti-based fixation system, for mandibular angle fractures, favorable to displacement. Additionally, finite element analysis was performed to assess the stress distribution in the plates and screws. Material and Method: Twenty eight polyurethane mandible replicas were used and uniformly sectioned on the left mandibular angle. These were divided into 4 groups considering the material of the plates and the internal fixation techniques: group Eng 1P, one 2.0-mm plate (tension zone of the mandible) and 4 screws 6 mm long; group Eng 2P, two 2.0-mm plates (one in the tension zone of the mandible and the other in the compression zone), the first fixed with 4 screws 6 mm long and the second with 4 screws 12 mm long. The same groups were created for the titanium alloy (Ti-15Mo). Each group was subjected to linear vertical loading at the first molar. Means and standard deviations were compared with respect to statistical significance (ANOVA; p < .05). Additionally, an three-dimensional finite element model reproducing the characteristics of the specimens used in the mechanical tests were created to evaluate the von Mises equivalent stress (σvM) in the plates and screws. Results: Statistically significant difference (p < .05) was found when the comparison between both internal fixation techniques (1 and 2 plates) was performed, regardless the materials of the plates (cpTi and Ti-15Mo). When considering the von Mises equivalent stress (σvM) values for the comparison between both groups (Eng and Ti-15Mo) with 1 plate, an decrease of 10.5% in the plate and an decrease of 29.0% in the screws for the titanium-molybdenum- based group was observed. Also, when comparing the same groups with 2 plates, the relevant fact was an decrease of 28.5% in the screws for the Ti- 15Mo group. Conclusion: The 2P technique showed…


Subject(s)
Bone Plates , Fracture Fixation, Internal , Mandible , Molybdenum , Titanium , Finite Element Analysis
13.
ImplantNews ; 10(5): 613-617, 2013. ilus
Article in Portuguese | LILACS, BBO - Dentistry | ID: lil-699625

ABSTRACT

Pacientes desdentados posteriores frequentemente apresentam pneumatização dos seios maxilares, dificultando a colocação de implantes dentários. Atualmente, o material mais utilizado para o preenchimento de seio maxilar é o enxerto ósseo autógeno retirado de sítios intra ou extrabucais. Apesar desse procedimento ter sua eficácia comprovada clínica e histologicamente, nem sempre é bem tolerado pelos pacientes devido à morbidade associada à manipulação da área doadora. Por isso, vários substitutos ósseos vêm sendo desenvolvidos. A proteína óssea morfogenética recombinante humana-2 surgiu recentemente como uma alternativa aos enxertos autógenos, oferecendo excelente padrão de reparo e/ou neoformação óssea, quando utilizada na reconstrução de rebordos alveolares, possibilitando a reabilitação com próteses implantossuportadas. Nesse trabalho foi feita uma revisão da literatura e apresentação de caso de levantamento de assoalho de seio maxilar bilateral com o uso da proteína óssea morfogenética.


Edentulous patients in the posterior maxillary region frequently present pneumatization of maxillary sinuses, which makes difficult installation of dental implants. Nowadays, most commonly used materials for maxillary sinus filling are autogenous bone grafts from intra- or extra-oral donor sites. Despite the elevated clinical and histologic success rates of this procedure, it is always not well-tolerated by patients due to morbidity seen after donor site manipulation. For this, many bone substitutes have been developed. Recombinant human bone morphogenetic protein-2 appeared recently as an alternative to autogenous bone grafts, offering excellent patterns of bone repair and/or neoformation when used for reconstruction of alveolar ridges, allowing rehabilitation with implant-supported prostheses. The aim of this article is to perform a literature review and also to report a case in which bilateral elevation of maxillary sinus floor was performed along with rhBMP-2.


Subject(s)
Humans , Female , Middle Aged , Bone Morphogenetic Proteins , Bone Transplantation , Maxillary Sinus
14.
Rev. Odontol. Araçatuba (Impr.) ; 32(1): 40-43, jan.-jun. 2011. ilus
Article in Portuguese | BBO - Dentistry | ID: biblio-856902

ABSTRACT

As infecções agudas buco-maxilo-faciais têm grande importância, tanto por sua alta casuística, como pelo risco de complicações. O objetivo deste estudo foi apresentar um caso clinico de extenso abscesso odontogênico em paciente de 31 anos de idade atendido pelo Serviço de Cirurgia e Traumatologia Buco-Maxilo-Facial da Faculdade de Odontologia de Araçatuba – UNESP, na região de Araçatuba, SP. As complicações das infecções odontogências embora pouco freqüentes podem levar o paciente ao óbito


Acute infections maxillo-facial are of great importance, both for its high population, as the risk of complications. The aim of this study was to present a clinical case of extensive odontogenic abscess in a patient of 31 years of age attended the Service of Surgery and Maxillo-Facial, Faculty of Dentistry of Araçatuba - UNESP in Araçatuba, SP. Complications of infections odontogências although infrequent can lead the patient to death


Subject(s)
Humans , Male , Adult , Abscess , Periapical Abscess , Infections
15.
Rev. Odontol. Araçatuba (Impr.) ; 31(2): 9-13, jul.-dez. 2010. ilus
Article in Portuguese | BBO - Dentistry | ID: biblio-856883

ABSTRACT

O câncer de boca e orofaringe é de comportamento agressivo e, no Brasil, a incidência é considerada uma das mais altas do mundo, sendo o mais comum da região de cabeça e pescoço. Acomete o gênero masculino de forma mais intensa e 70% dos casos são em indivíduos acima dos 50 anos de idade. Localiza-se, geralmente, em assoalho da boca e língua. Diante disso, o objetivo deste estudo é relatar um caso clínico de paciente do gênero masculino, 78 anos de idade, leucoderma que procurou atendimento hospitalar. Relatou fumo e alcoolismo frequente. No exame físico extrabucal, verificou-se a presença de nódulo linfático fixo, indolor de 1,5 a 2cm de diâmetro em região submandibular. Ao exame físico intrabucal constatou-se lesão ulcerada com cerca de 5 cm em sua maior extensão, localizada de assoalho bucal esquerdo até a região de orofaringe, coloração avermelhada, bordas endurecidas, superfície corrugada e base cartonada. O diagnóstico diferencial sugerido foi úlcera traumática, paracoccidioidomicose e carcinoma de células escamosas. A conduta realizada foi biópsia incisional e a peça obtida enviada à análise histopatológica, confirmando se tratar de carcinoma de células escamosas. O tratamento consistiu no esclarecimento do paciente a cerca da doença e da necessidade de procura por um centro de oncologia. Conclui-se que o exame clínico bucal acurado é importante em todas as lesões em boca, mesmo que a queixa principal não se concentre nesta. Nos indivíduos de maior risco o exame deve ser sistemático e indivíduos com lesões suspeitas devem ser encaminhados à consulta especializada


The oral and oropharyngeal cancer is aggressive and, in Brazil, the incidence is considered one of the world’s tallest, the most common of head and neck. It affects males more intensively and 70% of cases are in adults over 50 years of age. It is located usually on the floor of the mouth and tongue. Therefore, the purpose of this study is to report a case of male patient, 78 years of age, leukoderma who sought hospital care. Reported frequent smoking and alcoholism. On physical examination headgear, there was the presence of lymph node fixed, painless 1.5 to 2 cm in diameter in the submandibular region. Physical examination intraoral ulcer was found at about 5 cm at its greatest extent, localized to the left oral floor region of the oropharynx, reddish, hardened edges, surface and bottom corrugated carton. The differential diagnosis suggested was traumatic ulcer, paracoccidioidomycosis and squamous cell carcinoma. The approach employed was obtained by incisional biopsy and the piece sent to histopathological analysis, confirming the case of squamous cell carcinoma. The treatment consisted in clarifying the patient about the disease and the need to search for an oncology center. It is concluded that the oral clinical examination is accurate in all major injuries to mouth, even if the chief complaint does not focus on this. In individuals at high risk examination should be systematic and individuals with suspicious lesions should be referred to specialist consultation


Subject(s)
Humans , Male , Aged , Carcinoma, Squamous Cell , Diagnosis, Oral , Mouth Neoplasms
16.
Rev. Odontol. Araçatuba (Impr.) ; 31(2): 31-34, jul.-dez. 2010. ilus
Article in Portuguese | BBO - Dentistry | ID: biblio-856886

ABSTRACT

A displasia cemento-ósseo florida é uma lesão assintomática fibro-óssea presente na maxila e mandíbula de etiologia incerta. Possui maior expressão no gênero feminino, pacientes melanoderma e, de meia idade ao idoso. Esta displasia é uma condição assintomática que pode ser descoberta quando uma radiografia é realizada. A biópsia é contra-indicada para evitar infecção de difícil tratamento. Será descrito o caso clínico de uma mulher branca de 52 anos de idade, que procurou a Clínica de Cirurgia e Traumatologia Buco-maxilofacial da Faculdade de Odontologia de Araçatuba com dor na porção posterior esquerda da mandíbula. Após exame radiográfico foi diagnosticada a displasia cemento-óssea florida. Como tratamento, foi instituído o acompanhamento clínico e radiográfico


The florid cemento-osseous dysplasia is an asymptomatic lesion present in the fibro-osseous maxilla and mandible of uncertain etiology. It has higher expression in females, and patients melanoderm, middle-aged to elderly. This dysplasia is an asymptomatic condition that can be discovered when a radiograph is performed. A biopsy is contraindicated to avoid infection difficult to treat. We report the case of a white woman 52 years old, who searched the Clinic of Surgery and Traumatology Bucco-maxillofacial surgery, Faculty of Dentistry of Araçatuba with pain in the posterior portion of left mandible. After radiographic examination was diagnosed with florid cementoosseous dysplasia. Treatment was instituted clinical and radiographic


Subject(s)
Humans , Female , Middle Aged , Mouth Diseases , Mandible , Maxilla , Osteomyelitis
17.
Rev. Odontol. Araçatuba (Impr.) ; 31(2): 35-39, jul.-dez. 2010. ilus
Article in Portuguese | BBO - Dentistry | ID: biblio-856887

ABSTRACT

As fraturas do seio frontal são originadas a partir de acidentes de grande intensidade. Normalmente estão associadas com fraturas do terço médio da face, incluindo fraturas naso-órbito-etmoidal e zigomáticas. Várias modalidades de tratamento têm sido propostas. No presente caso utilizou-se do acesso bicoronal para reconstrução da parede anterior do seio frontal e, restabelecimento do contorno fronto-naso-órbito-etmoidal com resultados satisfatórios


The frontal sinus fractures are derived from accidents of great intensity. Are usually associated with fractures of the midface, including the naso-orbital fractures and zygomatic ethmoid. Several treatment modalities have been proposed. In this case it was used to access bicoronal reconstruction of the anterior frontal sinus, and restore contour fronto-naso-orbital-ethmoid with satisfactory results


Subject(s)
Humans , Male , Adult , Surgery, Oral , Frontal Sinus/surgery , Frontal Sinus/injuries
18.
Rev. Odontol. Araçatuba (Impr.) ; 31(1): 73-77, jan.-jun. 2010. ilus
Article in Portuguese | BBO - Dentistry | ID: biblio-856881

ABSTRACT

Os ferimentos faciais variam nas suas características clinicas e complexidade, merecendo uma abordagem adequada para cada caso, haja vista que os insucessos podem resultar em alterações estético-funcionais que podem ser prejudiciais tanto funcional como psicologicamente. Aspectos como tempo de exposição do ferimento, anestesia, fios de suturas e profilaxia antitetânica constituem fatores importante. O objetivo do trabalho é apresentar um caso clínico de extenso ferimento facial em paciente vítima de acidente automobilístico


Facial injuries vary in their clinical characteristics and complexity, deserves an appropriate approach for each case, considering that the failures may result in aesthetic and functional changes that can be harmfulboth functionally and psychologically. Aspects such as exposure time of the injury, anesthesia, suture materials and tetanus prophylaxis are important factors. The objective is to present a case of extensive facial injuries in an automobile accident patient


Subject(s)
Humans , Female , Adolescent , Accidents, Traffic , Facial Injuries
19.
Araçatuba; s.n; 2010. 89 p. ilus.
Thesis in Portuguese | BBO - Dentistry | ID: biblio-866446

ABSTRACT

Proposição: Caracterizar, química e morfologicamente, superfícies de implantes constituídos de ligas de titânio/molibidênio (Ti-15Mo), modificadas por feixe de laser, comparando-as com implantes da mesma liga com superfície usinada, empregando-se análises biomecânica, histológica e histométrica. Material e método: Dezesseis coelhos receberam 1 implante por tíbia das seguintes superfícies: superfície usinada (SU) e superfície modificada por laser (SML). Após 8 semanas foi realizado o teste biomecânico em 6 animais. As amostras teciduais dos outros 10 animais foram submetidas à análise histológica e histométrica da interface osso-implante. As superfícies dos implantes foram analisadas por MEV e EDS, antes da realização do procedimento cirúrgico. Resultado: A caracterização da superfície mostrou uma topografia rugosa, regular e homogênea, promovida pela irradiação por laser. A análise por EDS mostrou ausência de contaminação da superfície pelo método de modificação. O resultado na remoção por torque, no período, foi 51,5 N.cm para SU e > 90 N.cm para SML. A análise histológica mostrou formação e um íntimo contato do tecido ósseo em 42% da superfície do implante SML, o que não foi constatado no implante SU (24%). Dados histométricos (BIC%) mostraram diferenças estatisticamente significativas entre o grupo SU e o SML, para o implante inteiro (p = 0.0012), as 3 melhores espiras consecutivas da região cortical (p = 0.0012) e o espaço medular (p = 0.0082). Conclusão: O tratamento a laser é um procedimento limpo, reprodutível e promove características físico-químicas e topográficas, importantes para a osseointegração. Os implantes de Ti-15Mo com SML apresentaram resultados biomecânicos, histológicos e histométricos superiores aos usinados


Purpose: Characterize, chemically and morphologically, implants surfaces of titanium/molybdenum alloy (Ti-15Mo), modified by laser beam, and comparing them with the same alloy implants with machined surface, using biomechanical, histological and histometric analysis. Material and method: Sixteen rabbits received 1 implant by tibia of the following surfaces: machined surface (MS) and laser-modified surface (LMS). After 8 weeks a biomechanical test was performed in 6 animals. The tissue samples of the other 10 animals were submitted to histological and histometric analysis of bone-implant contact. The surfaces of the implants were analyzed by SEM and EDX prior to the surgical procedures. Result: The characterization of the surface showed a rough, regular and homogeneous topography, caused by laser irradiation. The EDX analysis showed no contamination of the surface by the method of modification. Average removal torque in the period was 51.5 N.cm for MS and > 90 N.cm for LMS. Histological analysis showed bone formation and close contact of bone tissue on 42% of the LMS implant surface, which was not observed in the MS implants (24%). Histometric data (BIC%) showed statistically significant differences between the control and test group for the entire implant (p = 0.0012), the 3 best consecutive spires of the cortical (p = 0.0012) and medullary area (p = 0.0082). Conclusion: The laser treatment is a clean, reproducible procedure, and promotes important physico-chemical and topographic characteristics for osseointegration. The Ti-15Mo implants with LMS showed better biomechanical, histological and histometric results than the machined ones


Subject(s)
Animals , Rabbits , Alloys , Dental Implants , Lasers , Titanium , Rabbits
20.
ImplantNews ; 6(1): 27-31, 2009. ilus
Article in Portuguese | LILACS, BBO - Dentistry | ID: lil-523900

ABSTRACT

Pacientes desdentados posteriores freqüentemente apresentam pneumatização dos seios maxilares, dificultando a colocação de implantes dentários. Atualmente o material mais utilizado para o preenchimento de seio maxilar é o enxerto ósseo autógeno retirado de sítios intra ou extrabucais. Apesar desse procedimento ter sua eficácia comprovada clínica e histologicamente, nem sempre é bem tolerado pelos pacientes devido à morbidade associada à manipulação da área doadora. Por isso, vários substitutos ósseos vêm sendo desenvolvidos. A proteína óssea morfogenética recombinante humana-2 surgiu recentemente como uma alternativa aos enxertos autógenos, oferecendo excelente padrão de reparo e/ou neoformação óssea quando utilizada na reconstrução de rebordos alveolares, possibilitando a reabilitação com próteses implantossuportadas. Nesse trabalho foi feita uma revisão da literatura e apresentação de caso de levantamento de assoalho de seio maxilar bilateral com o uso da proteína óssea morfogenética.


Subject(s)
Humans , Female , Adult , Bone Morphogenetic Proteins , Bone Transplantation , Maxillary Sinus/surgery
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