ABSTRACT
Background: The use of discolored teeth is required to test whitening products, and it is difficult to obtain them, given their scarcity. Objective: To present a technique for in vitro darkening of extracted teeth simulating pulpal necrosis discoloration. Materials and Methods: Hemolysates I and II from human blood were subjected or not to laser irradiation (442 nm) for 1 h. The concentration of oxyhemoglobin (O2Hb) was analyzed by ultraviolet/visible spectroscopy, and the conversion of O2Hb to methemoglobin (MetHb) by transmission spectroscopy was assessed immediately and after 3 and 40 days. For darkening evaluation, bovine incisors were divided into two groups (n = 25), and their pulp chambers were filled with hemolysate solution II (HSII) and hemolysate II solution + laser (HSII+L). After storage in artificial saliva for 40 days at 37°C, color changes were measured by a colorimeter and ΔE was compared with the NBS parameters. Data were analyzed using a mixed linear model (α=5%). Results: HSII+L presented the lowest O2Hb and higher MetHb. The conversion of O2Hb to MetHb in HSII+L was 42% higher than in HSII. Both groups were effective in darkening the teeth, according to the NBS. Darkening stabilized from day 35. HSII promoted a marked color difference. Conclusion: The proposed technique was effective in darkening the extracted teeth simulating necrosis discoloration for in vitro models.
ABSTRACT
A anemia falciforme é uma doença genética caracterizada pelo alto índice de morbimortalidade, considerada como a mais grave entre as doenças falciformes. As opções terapêuticas mais eficazes atualmente disponíveis para tratamento desta hemoglobinopatia são transplante de medula óssea (TMO) e hidroxiuréia (HU). O TMO apesar de ser a medida curativa é considerado de alto risco por apresentar diversos graus de complicações e significativo nível de mortalidade. O uso de HU em crianças portadoras de anemia falciforme tem proporcionado redução de complicações clínicas e aumento significativo na expectativa de vida, por promover elevação dos níveis de hemoglobina fetal, da concentração de hemoglobina e do VCM, bem como redução da hemólise e de eventos vaso-oclusivos. Desse modo, a HU é considerada como melhor opção terapêutica atualmente disponível. Porém, por ser apontada como droga potencialmente carcinogênica, há questionamentos quanto aos benefícios e toxicidades quando utilizada por longo período. Este trabalho teve como proposta, avaliar por meio da revisão literária, os riscos, benefícios e efeitos adversos da hidroxiuréia em crianças.
Sickle cell anemia is a genetic disease characterized by a high morbimortality rate, it is considered as the most serious among all sickle cell diseases. The most effective therapeutic options available nowadays for the treatment of this hemoglobinopathy are bone morrow transplantation (BMT) and hydroxyurea (HU). BMT is considered a high risk procedure due to the different complications and significant mortality rates. The use of HU for children with sickle cell anemia has reduced the clinical complications and given a significant increase in life expectancy by augmenting the fetal hemoglobin levels and hemoglobin concentrations and reducing cytomegalovirus, as well as reducing hemolysis and vaso-occlusive events. Thus, HU is considered the best therapeutic option currently available. However, as HU has been identified as a potentially carcinogenic drug, there are questions related to the benefits and toxicities when it is used over long periods of time. This work aimed at evaluating, through a review of the literature, the risks, benefits and adverse effects of the use of hydroxyurea in children.
