ABSTRACT
In order to understand the mechanisms of poor osseointegration following dental implants in type 2 diabetics, it is important to study the biological properties of alveolar bone osteoblasts isolated from these patients. We collected alveolar bone chips under aseptic conditions and cultured them in vitro using the tissue explants adherent method. The biological properties of these cells were characterized using the following methods: alkaline phosphatase (ALP) chemical staining for cell viability, Alizarin red staining for osteogenic characteristics, MTT test for cell proliferation, enzyme dynamics for ALP contents, radio-immunoassay for bone gla protein (BGP) concentration, and ELISA for the concentration of type I collagen (COL-I) in the supernatant. Furthermore, we detected the adhesion ability of two types of cells from titanium slices using non-specific immunofluorescence staining and cell count. The two cell forms showed no significant difference in morphology under the same culture conditions. However, the alveolar bone osteoblasts received from type 2 diabetic patients had slower growth, lower cell activity and calcium nodule formation than the normal ones. The concentration of ALP, BGP and COL-I was lower in the supernatant of alveolar bone osteoblasts received from type 2 diabetic patients than in that received from normal subjects (P < 0.05). The alveolar bone osteoblasts obtained from type 2 diabetic patients can be successfully cultured in vitro with the same morphology and biological characteristics as those from normal patients, but with slower growth and lower concentration of specific secretion and lower combining ability with titanium than normal ones.
Subject(s)
Humans , Male , Middle Aged , Alveolar Process/cytology , Calcification, Physiologic/physiology , Dental Implants , /physiopathology , Osteoblasts/physiology , Osteocalcin/analysis , Alkaline Phosphatase/analysis , Collagen Type I/analysis , Osseointegration/physiology , Osteoblasts/cytology , Osteoblasts/pathology , Primary Cell Culture/methodsABSTRACT
The aims of this study were to characterize the microstructure of a commercially pure titanium (cpTi) surface etched with HCl/H2SO4 (AE-cpTi) and to investigate its in vitro cytocompatibility compared to turned cpTi (T-cpTi). T-cpTi showed a grooved surface and AE-cpTi revealed a surface characterized by the presence of micropits. Surface parameters indicated that the AE-cpTi surface is more isotropic and present a greater area compared to T-cpTi. The oxide film thickness was similar between both surfaces; however, AE-cpTi presented more Ti and O and less C. Osteoblastic cell proliferation, alkaline phosphatase activity, and bone-like nodule formation were greater on T-cpTi than on AE-cpTi. These results show that acid etching treatment produced a surface with different topographical and chemical features compared to the turned one, and such surface modification affected negatively the in vitro cytocompatibility of cpTi as demonstrated by decreasing culture growth and expression of osteoblastic phenotype.
O objetivo deste estudo foi caracterizar a microestrutura de uma superfície de titânio comercialmente puro (cpTi) condicionada com HCl/H2SO4 (acid etched) (AE-cpTi) e investigar sua citocompatibilidade in vitro, comparada à do cpTi usinado (turned) (T-cpTi). O T-cpTi apresentou uma superfície com sulcos e o AE-cpTi exibiu uma superfície caracterizada pela presença de micro-vales. Os parâmetros de superfície indicaram que a superfície AE-cpTi é mais isotrópica e apresenta uma área maior quando comparada à superfície T-cpTi. A espessura da camada de óxido foi similar para as duas superfícies; no entanto, a AE-cpTi apresentou maiores quantidades de Ti e O e menor, de C. A proliferação de células osteoblásticas, a atividade de fosfatase alcalina e a formação de matriz mineralizada foram maiores na superfície T-cpTi que na AE-cpTi. Esses resultados mostram que o condicionamento ácido produziu uma superfície com características topográficas e químicas diferentes quando comparadas às da superfície usinada. Além disso, observou-se que essas modificações de superfície afetaram de forma negativa a citocompatibilidade in vitro do cpTi como demonstrado pela inibição da proliferação celular e da expressão do fenótipo osteoblástico.
Subject(s)
Humans , Acid Etching, Dental , Biocompatible Materials/pharmacology , Dental Materials/pharmacology , Osteoblasts/drug effects , Titanium/pharmacology , Alkaline Phosphatase/analysis , Alveolar Process/cytology , Biocompatible Materials/chemistry , Biomarkers/analysis , Cells, Cultured , Carbon/chemistry , Cell Adhesion/drug effects , Cell Division/drug effects , Cell Proliferation/drug effects , Cell Survival/drug effects , Dental Materials/chemistry , Hydrochloric Acid/chemistry , Interferometry , Materials Testing , Microscopy, Electron, Scanning , Osteogenesis/drug effects , Phenotype , Photoelectron Spectroscopy , Surface Properties , Sulfuric Acids/chemistry , Titanium/chemistryABSTRACT
O presente trabalho teve por objetivo estudar histomorfologicamente, a influência da radiaçäo X, 24 horas antes da extraçäo dental, sobre a cronologia do processo de reparo nas feridas decorrentes desta intervençäo. Foram empregados 60 ratos jovens. Estes ratos foram divididos em 2 grupos: Grupo Controle (I) e Grupo Irradiado (II). Os animais foram sacrificados aos 3, 7, 14, 28 e 40 dias após as extraçöes dentais. As peças obtidas sofreram o tratamento laboratorial de rotina para se obter lâminas corada com hematoxilina e eosina. Concluiu-se que: 1) Houve retardo no início da proliferaçäo fibroblástica e de vasos sanguíneos no Grupo Irradiado; 2) A irradiaçäo 24 horas antes do ato cirúrgico provocou um severo atraso na cronologia do processo de reparo alveolar