RESUMEN
BACKGROUND: This study evaluated tibia's macroscopic structure, mechanical properties, and bone microarchitecture in rats with type 1 diabetes mellitus (T1DM). METHODS: Eighteen animals were divided into three groups (n=6): Non-diabetic (ND), diabetic (D), and diabetic+insulin (DI). T1DM was induced by streptozotocin; insulin was administered daily (4IU). The animals were euthanized 35 days after induction. The tibiae were removed and analyzed using macroscopic, micro-computed tomography (micro-CT) and three-point bending. The macroscopic analysis measured proximal-distal length (PD), antero-posterior thickness (AP) of proximal (AP-P) and distal (AP-D) epiphysis, and lateral-medial thickness (LM) of proximal (LM-P) and distal (LM-D) epiphysis. Micro-CT analysis closed porosity, tissue mineral density, and cortical thickness. The three-point bending test measured maximum strength, energy, and stiffness. RESULTS: The macroscopic analysis showed that D presented smaller measures of length and thickness (AP and AP-P) than ND and DI. More extensive measurements were observed of LM and AP-D thickness in DI than in D. In micro-CT, DI showed larger cortical thickness than D. Mechanical analysis showed lower strength in D than in other groups. CONCLUSIONS: T1DM reduces bone growth and mechanical strength. Insulin therapy in diabetic rats improved bone growth and fracture resistance, making diabetic bone similar to normoglycemic animals.
Asunto(s)
Densidad Ósea , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Hipoglucemiantes , Insulina , Tibia , Microtomografía por Rayos X , Animales , Tibia/diagnóstico por imagen , Tibia/efectos de los fármacos , Tibia/patología , Insulina/administración & dosificación , Insulina/uso terapéutico , Ratas , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/fisiopatología , Masculino , Densidad Ósea/efectos de los fármacos , Hipoglucemiantes/uso terapéutico , Ratas Wistar , Fenómenos BiomecánicosRESUMEN
AIM: This study evaluated the transdentinal cytotoxic effects of enzymatic agents (EA) for chemomechanical carious tissue removal on human dental pulp cells. METHODOLOGY: The groups were based on the performed dentine treatments (n = 8): G1: Positive Control (PC - no treatment); G2: Negative Control (NC - 35% H2 O2 for 2 min); G3: Brix 3000™ (BX) for 30 s; G4: BX for 2 min; G5: Papacarie Duo™ (PD) for 30 s; G6: PD for 2 min. The cells were evaluated for viability (VB; MTT assay) and production of reactive oxygen species (ROS; DCFH-DA assay) and nitric oxide (NO; Griess reagent). A scanning electron microscope provided morphological chemical analyses and energy-dispersive X-ray spectroscopy. The data were submitted to the one-way anova statistical test complemented by Tukey (p < .05). RESULTS: Cell viability decreased by 21.1% and 58.4% in G5 and G6, respectively. ROS production in G3 and G4 maintained basal levels but increased by 171.2% and 75.1% in G5 and G6, respectively. CONCLUSIONS: The Brix3000™ enzymatic agent did not cause indirect cytotoxic effects on pulp cells, regardless of the application time. Conversely, Papacarie Duo™ reduced viability and increased ROS production by pulp cells.