Avaliação clínica e histológica de ratos submetidos à injeção em ventre lingual de ácido hialurônico em distintas concentrações

• Ano de defesa: 2011
• Autor(a) principal: Borghetti, Ruchielli Loureiro
• Orientador(a): Figueiredo, Maria Antonia Zancanaro de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul; Porto Alegre
• Palavras-chave em Português: ODONTOLOGIA; ESTOMATOLOGIA; HISTOLOGIA; ÁCIDO HIALURÔNICO
• Link de acesso: http://hdl.handle.net/10923/395

Hyaluronic Acid (HA) is currently the most applied resorbable filling material. Its indiscriminate use has showed the adverse reactions. Scientific literature does not conclusively clarify the aetiology of the adverse effects, which can occur after material injection. The current research has aimed at evaluating, through clinical and histological analysis, local and systemic tissue response to the injection of 2 different hyaluronic acid concentrations in rat’s tongue. Fifty-four female Wistar rats (Rattus norvegicus) were randomically allocated into 3 groups according to the treatment (5. 5mg/mL HA, 25mg/mL HA and 0. 9 % NaCl - control) and 3 experimental times (7 days, 60 days and 90 days). Immediately before euthanasia, clinical analysis was performed guided by the parameters of presence and absence of inflammatory signs or any other alteration of the normal pattern. After euthanasia, the tongue and the right kidney of each animal were removed for microscopic analysis. Presence or absence of inflammatory reaction was measured in the tongue sections stained by hematoxylin and eosin (HE) and reactions were classified as mild, moderate or severe. The proportion of collagen fibers present was established in the sections stained with picrosirius. Presence or absence of inflammatory response in the total extension of each slide was observed in the kidney samples (HE). The clinical changes present were not statistically significant among groups (Kruskal-Wallis; p>0. 05). The groups that received HA injection presented a higher degree of inflammation if compared to the control groups in all monitoring periods (Kruskal-Wallis, p<0. 01). Regarding fibroplasias, the 25mg/mL HA group tended to form more collagen if compared to the control group (ANOVA Mixed Models; p=0. 016). In 100% of the analyzed kidney samples, there was no inflammatory reaction. According to the methodology used in this study, the obtained results allows the conclusion that (1) HA at 5. 5 and 25mg/mL presented variable and occasional clinic changes in all evaluation periods; (2) HA in the chosen concentrations, within 7 days, promoted a moderate degree of tissue inflammation; (3) After 60 and 90 days, inflammatory reaction surrounding HA particles became milder, reducing risks of adverse reactions to the material; (4) HA at 25mg/mL provoked larger concentrations of collagen if compared to the control group; (5) There was no inflammatory response and/or renal systemic migration due to the injection of HA at 5. 5mg/mL and 25mg/mL in up to 90 days of monitoring.