ABSTRACT
SUMMARY: To evaluate the histological adverse effects of alendronate administered systemically and topically in combination with orthodontic movement by intense force. Thirty-six 24-week-old female Wistar rats, ovariectomized, were used and divided into three groups (n = 12/group): control, locally treated with saline (0.07 ml/kg/week) (group 1) and experimental, treated with alendronic acid systemically (0.07 mg/kg/week) (group 2) and locally (7 mg/kg/week) (group 3). At 14 days, an orthodontic anchor was installed in the right first molar, and a force of 144 cN was applied for 28 days. The samples were processed for histological evaluation. Descriptive statistics, Shapiro-Wilk tests, one-way ANOVA with Bonferroni correction, one-way repeated measures ANOVA and chi-square tests were performed. All tests were statistically significant at p <0.05. The adverse events found in all groups were inflammation and osteoclastic activity. In the bisphosphonate-treated groups, there were statistically significant differences (p = 0.005) in the osteoclastic activity between the two hemiarcates. All rats in group 2 presented paralytic ileus. Compared to local administration, systemic treatment with alendronic acid produces more adverse effects, such as inflammation, fibrinoid necrosis, and osteoclastic activity. During the application of intense forces, it was not possible to show that there is necrosis associated with bisphosphonates.
Evaluar los efectos adversos histológicos del alendronato administrado sistémica y tópicamente en combinación con movimientos ortodóncicos de fuerza intensa. Treinta y seis ratas Wistar hembras de 24 semanas de edad, ovariectomizadas, fueron utilizadas y divididas en tres grupos (n = 12/grupo): control, tratado localmente con solución salina (0,07 ml/kg/semana) (grupo 1) y experimental, tratados con ácido alendrónico por vía sistémica (0,07 mg/kg/semana) (grupo 2) y local (7 mg/kg/semana) (grupo 3). A los 14 días se instaló un anclaje de ortodoncia en el primer molar derecho y se aplicó una fuerza de 144 cN durante 28 días. Las muestras fueron procesadas para evaluación histológica. Se realizó estadística descriptiva, pruebas de Shapiro-Wilk, ANOVA de una vía con corrección de Bonferroni, ANOVA de medidas repetidas de una vía y pruebas de chi-cuadrado. Todas las pruebas fueron estadísticamente significativas con un p <0,05. Los eventos adversos encontrados en todos los grupos fueron inflamación y actividad osteoclástica. En los grupos tratados con bisfosfonatos hubo diferencias estadísticamente significativas (p = 0,005) en la actividad osteoclástica entre los dos hemiarcados. Todas las ratas del grupo 2 presentaron íleo paralítico. En comparación con la administración local, el tratamiento sistémico con ácido alendrónico produce más efectos adversos, como inflamación, necrosis fibrinoide y actividad osteoclástica. Durante la aplicación de fuerzas intensas, no fue posible demostrar que existe necrosis asociada con los bisfosfonatos.
Subject(s)
Animals , Female , Rats , Tooth Movement Techniques/instrumentation , Alendronate/adverse effects , Bone Density Conservation Agents/adverse effects , Maxilla/pathology , Bone Resorption/chemically induced , Ovariectomy , Analysis of Variance , Rats, Wistar , Orthodontic Anchorage Procedures , Inflammation/chemically inducedABSTRACT
Abstract The aim of this study was to evaluate the effect of acute administration of nicotine and ethanol on tooth movement in rats. Two hundred rats were divided into eight groups: S: saline; N: nicotine; E: ethanol; NE: nicotine and ethanol; SM: saline with tooth movement; NM: nicotine with tooth movement; EM: ethanol with tooth movement; and NEM: nicotine and ethanol with tooth movement. All the solutions were applied for 32, 44, or 58 days, according to the subgroup. Orthodontic movement (25 cN) was initiated 30 days after solution administration in the groups with tooth movement. The rats were euthanized 2, 14, or 28 days after initiation of tooth movement. Tooth sections were stained using picrosirius and tartrate-resistant acid phosphatase (TRAP). The data were compared by ANOVA using Tukey's HSD and Games-Howell. On day 28 of tooth movement, the NEM group had a lower percentage of type I collagen compared to the SM group (p = 0.0448), and the S group had a higher number of osteoclasts/μm2 compared to the N group (p = 0.0405). Nicotine and ethanol did not affect the tooth movement rate, regardless of induction of orthodontic movement. Nicotine influenced the number of osteoclasts by decreasing their quantity when dental movement was not induced. When nicotine was associated with ethanol, it interfered in the maturation of collagen fibers during orthodontic movement.
Subject(s)
Animals , Male , Tooth Movement Techniques/methods , Bone Regeneration/drug effects , Bone Resorption/chemically induced , Ethanol/administration & dosage , Alveolar Process/drug effects , Nicotine/administration & dosage , Osteoclasts/drug effects , Osteogenesis/drug effects , Reference Values , Time Factors , Random Allocation , Collagen/drug effects , Rats, Wistar , Tartrate-Resistant Acid PhosphataseABSTRACT
PURPOSE: Bone metastasis invariably increases morbidity and mortality. This study compares the effects of ibandronate and paclitaxel on bone structure and its mechanical properties and biochemical turnover in resorption markers using an immunocompetent Walker 256-Sprague-Dawley model, which was subjected to tumor-induced osteolysis. MATERIALS AND METHODS: Seventy rats were divided equally into 4 groups: 1) sham group (SHAM), 2) tumor group (CANC), 3) ibandronate treated group (IBAN), and 4) paclitaxel treated group (PAC). Morphological indices [bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp)] and mechanical properties (failure load, stiffness) were evaluated after thirty days of treatment period. Bone resorption rate was analysed using serum deoxypyridinoline (Dpd) concentrations. RESULTS: Morphological indices showed that ibandronate (anti-resorptive drug) had a better effect in treating tumor-induced architectural changes in bone than paclitaxel (chemotherapeutic drug). The deterioration in bone architecture was reflected in the biomechanical properties of bone as studied with decreased failure load (F(x)) and stiffness (S) of the bone on the 30th day postsurgery. Dpd concentrations were significantly lower in the IBAN group, indicating successful inhibition of bone resorption and destruction. CONCLUSION: Ibandronate was found to be as effective as higher doses of paclitaxel in maintaining stiffness of bone. Paclitaxel treatment did not appear to inhibit osteoclast resorption, which is contrary to earlier in-vitro literature. Emphasis should be placed on the use of immunocompetent models for examining drug efficacy since it adequately reflects bone metastasis in clinical scenarios.
Subject(s)
Animals , Male , Rats , Amino Acids , Biomechanical Phenomena/drug effects , Bone Density/drug effects , Bone Neoplasms/drug therapy , Bone Resorption/chemically induced , Diphosphonates/pharmacology , Immunocompetence , Neoplasm Metastasis , Osteolysis , Paclitaxel/pharmacology , Rats, Sprague-DawleyABSTRACT
This study aimed to evaluate by the intra-osseous implant technique the most commonly used materials for pulp therapy in pediatric dentistry: calcium hydroxide (CH), Guedes Pinto paste and CTZ paste, according to FDI (1980) and ANSI/ADA (1982) recommendations. Thirty guinea pigs, 10 for each material, divided into experimental periods of 4 and 12 weeks received one implant on each side of the lower jaw symphysis. The external lateral tube wall served as control for the technique. At the end of the observation periods, the animals were euthanized and specimens were prepared for routine histological examination. It was observed that CH and CTZ paste induced severe inflammation, a large amount of necrotic tissue, lymphocytes, foreign body cells and bone resorption, while Guedes Pinto Paste induced little or no inflammation in the 4-week observation period. After 12 weeks, the reactions to CH and Guedes Pinto paste were also absent/mild, presenting a general pattern of replacement by recently formed bone tissue while a moderate to severe inflammatory response was observed with CTZ paste. Guedes Pinto paste presented acceptable biocompatibility levels in both analyzed periods; CH only showed acceptable biocompatibility in the 12-week period while CTZ paste showed no biocompatibility in both periods. Among the tested materials, only Guedes Pinto paste presented an acceptable biocompatibility.
A pesquisa teve como objetivo avaliar a biocompatibilidade através da técnica de implantes intra-ósseos dos materiais utilizados em odontopediatria para tratamento pulpar: hidróxido de cálcio, pastas Guedes Pinto e CTZ, de acordo com as recomendações da FDI (1980) e ANSI/ADA(1982). Trinta guinea pigs, dez para cada material, divididos em períodos experimentais de 4 e 12 semanas receberam um implante em cada lado da sínfise mandibular. A parede lateral externa do copo serviu como controle para a técnica. No final dos períodos experimentais, os animais foram sacrificados e os espécimes preparados para o exame histológico de rotina. Observou-se que o hidróxido de cálcio e a pasta CTZ mostraram reação inflamatória severa, grande quantidade de tecido necrosado, linfócitos, células de corpo estranho e reabsorção óssea; enquanto a pasta Guedes Pinto induziu pouca ou nenhuma inflamação no período de 4 semanas. Após 12 semanas as reações para o hidróxido de cálcio e pasta Guedes Pinto foram ausentes/suaves apresentando um padrão geral de substituição por tecido ósseo neoformado, enquanto uma resposta inflamatória de moderada a severa foi observada para a pasta CTZ. A pasta Guedes Pinto apresentou níveis aceitáveis de biocompatibilidade nos dois períodos analisados; hidróxido de cálcio apresentou biocompatibilidade aceitável somente no período de 12 semanas e a pasta CTZ não mostrou biocompatibilidade em ambos os períodos. Entre estes, apenas a pasta Guedes Pinto apresentou níveis de biocompatibilidade nos dois períodos analisados.
Subject(s)
Animals , Guinea Pigs , Biocompatible Materials/pharmacology , Mandible/drug effects , Root Canal Filling Materials/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Inflammatory Agents/pharmacology , Bone Resorption/chemically induced , Calcium Hydroxide/pharmacology , Chloramphenicol/pharmacology , Drug Combinations , Eugenol/pharmacology , Giant Cells, Foreign-Body/drug effects , Hydrocarbons, Iodinated/pharmacology , Lymphocytes/drug effects , Macrophages/drug effects , Necrosis , Neutrophils/drug effects , Osteitis/chemically induced , Osteogenesis/drug effects , Prednisolone/analogs & derivatives , Prednisolone/pharmacology , Rifamycins/pharmacology , Time Factors , Tetracycline/pharmacology , Zinc Oxide/pharmacologyABSTRACT
BACKGROUND & OBJECTIVE: It is not clear how lathyrism affects the systemic bone metabolism. We therefore undertook a study to observe periodontal and systemic bone changes by performing radiological, metabolic, and bone densitometric evaluations in rats with experimental lathyrism. METHODS: A total of 30 rats were used. Experimental lathyrism was induced by once daily subcutaneous administration of beta-aminopropionitrile (beta-APN), at a dose of 5 mg beta-APN/0.4 ml per 100 g of body weight for 40 days. After 40 days, vertebral bone mineral density was analyzed by means of dual energy X-ray absorbtiometry in both groups. Blood was drawn by cardiac puncture and the animals were decapitated. Serum calcium levels were measured. Right mandibles were removed and radiographs were obtained. Alveolar bone level was determined in the radiographs. RESULTS: In all lathyritic rats, alveolar bone level was pathologically decreased with visible resorption. Vertebral bone mineral density values of lathyritic rats did not differ significantly from those of the control group. Compared to controls, there was a statistically significant decrease in serum calcium levels in the lathyritic group (P<0.001). INTERPRETATION & CONCLUSION: Significant alveolar bone resorption without alterations in vertebral bone mineral density indicated that lathyrogen administration for 40 days presumably has not caused systemic demineralization. This model could be used for studying the role of local and systemic agents on periodontal alveolar bone resorption.
Subject(s)
Alveolar Process/drug effects , Aminopropionitrile/toxicity , Animals , Bone Density/drug effects , Bone Resorption/chemically induced , Bone and Bones/drug effects , Lathyrism/chemically induced , Male , Periodontium , Rats , Rats, WistarABSTRACT
Os biofosfonatos säo eficientes bloqueadores das reabsorçöes e, por isso, säo utilizados no controle das doenças metabólicas ósseas. Os mecanismos pelos quais essas drogas interferem nos processos de reabsorçäo ainda näo estäo totalmente esclarecidos, mas incluem a inibiçäo da funçäo e a alteraçäo da morfologia dos clastos e precursores, além da atuaçäo como citotóxicos sobre os macrófagos e os osteoblastos. Num modelo experimental de movimentaçäo dentária induzida, procurou-se verificar, microscopicamente, a influência do clodronato sobre a morfologia do osso alveolar, do ligamento periodontal e do cemento dos primeiros molares superiores de 45 ratas com 90 dias de vida, nos tempos experimentais de 24 horas, 3, 5, 7, 10 e 21 dias de movimento. Os resultados microscópicos revelaram que a administraçäo do clodronato näo interferiu em nenhuma das situaçöes referidas, inclusive durante o movimento dentário induzido, nas diversas fases analisadas. A presença localizada mais intensa de infiltrado inflamatório crônico sugere uma influência dos bisfosfonatos nos processos inflamatórios