Mast cells and immunoexpression of FGF-1 and Ki-67 in rat subcutaneous tissue following the implantation of Biodentine and MTA Angelus.

AIM: To compare the formation of fibrous capsules around Biodentine and MTA Angelus implants as well as the participation of fibroblast growth factor-1 (FGF-1) and mast cells in the tissue response to these endodontic materials. METHODOLOGY: Sixty polyethylene tubes filled with Biodentine or MTA, and empty tubes (control group) were implanted into the dorsal subcutaneous tissues of male rats. After 7, 15, 30 and 60 days, the specimens were embedded in paraffin and the number of fibroblasts and mast cells was quantified in the sections stained with Masson's trichrome or Alcian Blue, respectively. FGF-1 and Ki-67 were detected by immunohistochemistry, and the number of immunolabelled cells was computed. The collagen content was estimated in the picrosirius red-stained sections. The data were subjected to two-way ANOVA followed by Tukey's test (P ≤ 0.05). RESULTS: The capsules were associated with a significant increase (P < 0.0001) in the number of fibroblasts and mast cells, and in the collagen content over time. A significant decrease (P < 0.0001) in the immunoexpression of FGF-1 and Ki-67 was observed in all groups from the 7th-60th day. At 60 days, the number of fibroblasts (P = 0.0226) and the collagen content (P < 0.0001) were significantly greater in MTA than Biodentine specimens, while the greatest number of mast cells and FGF-1-immunolabelled cells was observed in Biodentine specimens (P < 0.0001). A significant difference in Ki-67 immunoexpression was not detected between specimens of Biodentine and MTA. CONCLUSIONS: The collagen-rich capsule formed slowly around Biodentine in comparison with MTA. FGF-1 and mast cells participated in capsule remodelling, stimulating fibroblast proliferation and subsequent collagen production, in response to subcutaneous implants.

Zirconium oxide and niobium oxide used as radiopacifiers in a calcium silicate-based material stimulate fibroblast proliferation and collagen formation.

AIM: To evaluate the influence of the addition of microparticulate (micro) and nanoparticulate (nano) zirconium oxide (ZrO2 ) and niobium pentoxide (Nb2 O5 ) to a calcium silicate-based cement (CS) on the subcutaneous healing process in rats compared with MTA Angelus™. METHODOLOGY: In each rat, two polyethylene tubes filled with the following materials: (i) MTA; (ii) CS + ZrO2 micro; (iii) CS + ZrO2 nano; (iv) CS + Nb2 O5 micro or (v) CS + Nb2 O5 nano were implanted subcutaneously; empty polyethylene tubes were used in the Control group. After 7, 15, 30 and 60 days, the specimens (n = 5 per group in each period) were fixed and embedded in paraffin. Masson's trichrome sections were used to obtain the volume density of the inflammatory cells (VvIC) and fibroblasts (VvFb). The sections were also stained with Picrosirius-red to calculate the birefringent collagen content. Fibroblast growth factor-1 (FGF-1) was detected by immunohistochemistry, and the number of immunolabelled cells was obtained. The data were subjected to two-way anova followed by Tukey's test (P ≤ 0.05). RESULTS: At all periods, the VvIC was significantly lower (P < 0.001) in all the CS and Control groups than in the MTA group. At all periods, the VvFb was reduced significantly (P = 0.023) in the MTA group in comparison with the other groups. In addition, the number of immunolabelled cells in the capsules of the CS groups was significantly higher (P < 0.001) than in the MTA group at all time-points. CONCLUSIONS: The experimental materials (CS + ZrO2 and CS + Nb2 O5 ) induced fibroblast proliferation and accelerated the regression of the inflammatory reaction. However, the addition of nanoparticulate radiopacifiers did not improve the biological properties of a calcium silicate-based cement when compared to microparticulate agents.

Immunolocalization of FGF-2 and VEGF in rat periodontal ligament during experimental tooth movement.

OBJECTIVE: This article aimed at identifying the expression of fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF) in the tension and pressure areas of rat periodontal ligament, in different periods of experimental orthodontic tooth movement. METHODS: An orthodontic force of 0.5 N was applied to the upper right first molar of 18 male Wistar rats for periods of 3 (group I), 7 (group II) and 14 days (group III). The counter-side first molar was used as a control. The animals were euthanized at the aforementioned time periods, and their maxillary bone was removed and fixed. After demineralization, the specimens were histologically processed and embedded in paraffin. FGF-2 and VEGF expressions were studied through immunohistochemistry and morphological analysis. RESULTS: The experimental side showed a higher expression of both FGF-2 and VEGF in all groups, when compared with the control side (P < 0.05). Statistically significant differences were also found between the tension and pressure areas in the experimental side. CONCLUSION: Both FGF-2 and VEGF are expressed in rat periodontal tissue. Additionally, these growth factors are upregulated when orthodontic forces are applied, thereby suggesting that they play an important role in changes that occur in periodontal tissue during orthodontic movement.

Immunolocalization of FGF-2 and VEGF in rat periodontal ligament during experimental tooth movement

OBJECTIVE: This article aimed at identifying the expression of fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF) in the tension and pressure areas of rat periodontal ligament, in different periods of experimental orthodontic tooth movement. METHODS: An orthodontic force of 0.5 N was applied to the upper right first molar of 18 male Wistar rats for periods of 3 (group I), 7 (group II) and 14 days (group III). The counter-side first molar was used as a control. The animals were euthanized at the aforementioned time periods, and their maxillary bone was removed and fixed. After demineralization, the specimens were histologically processed and embedded in paraffin. FGF-2 and VEGF expressions were studied through immunohistochemistry and morphological analysis. RESULTS: The experimental side showed a higher expression of both FGF-2 and VEGF in all groups, when compared with the control side (P < 0.05). Statistically significant differences were also found between the tension and pressure areas in the experimental side. CONCLUSION: Both FGF-2 and VEGF are expressed in rat periodontal tissue. Additionally, these growth factors are upregulated when orthodontic forces are applied, thereby suggesting that they play an important role in changes that occur in periodontal tissue during orthodontic movement. .

OBJETIVO: o objetivo desse estudo foi identificar a expressão do fator de crescimento de fibroblastos 2 (FGF-2) e do fator de crescimento vascular endotelial (VEGF) nos lados de tensão e pressão do ligamento periodontal de ratos, durante movimento ortodôntico experimental, em diferentes períodos de tempo. MÉTODOS: uma força ortodôntica de 0,5N foi aplicada no primeiro molar superior direito de 18 ratos Wistar machos, por períodos de 3 (grupo I), 7 (grupo II) e 14 dias (grupo III). O primeiro molar do lado oposto foi utilizado como controle. Os animais foram sacrificados nos períodos de tempo mencionados, sendo a arcada superior removida e fixada. Após a desmineralização, os espécimes foram processados histologicamente e embebidos em parafina. A expressão do FGF-2 e do VEGF foram estudadas por meio de análise imuno-histoquímica. RESULTADOS: o ligamento periodontal dos dentes submetidos à movimentação ortodôntica mostraram maior expressão tanto de FGF-2 quanto de VEGF, em todos os grupos experimentais, quando comparados com os dentes do lado controle (p < 0,05). Diferenças estatisticamente significativas entre os lados de tensão e pressão também foram encontradas nos dentes submetidos à movimentação ortodôntica. CONCLUSÕES: tanto o FGF-2 quanto o VEGF são expressos no tecido periodontal de ratos, e esses fatores de crescimento são aumentados quando forças ortodônticas são aplicadas, sugerindo que esses desempenham um papel importante na reorganização do periodonto durante o movimento ortodôntico. .

Resposta tecidual induzida por Biodentine™ e MTA Branco em subcutâneo de ratos / Tissue reaction induced by Biodentine™ and White MTA in rat subcutaneous

Biodentine™ é um biomaterial à base de silicato de cálcio produzido, segundo o fabricante, com o intuito de apresentar propriedades físico-químicas e biológicas superiores ao MTA. Nosso objetivo foi avaliar a resposta tecidual promovida por Biodentine™ (BDT) e MTA Angelus Branco em subcutâneo de ratos. Foram utilizados ratos adultos distribuídos em 3 grupos (n=20/grupo), segundo o material preenchendo os tubos de polietileno implantados no subcutâneo: BDT, MTA e GC (controle, tubos vazios). Após 7, 15, 30 e 60 dias, os implantes e os tecidos adjacentes foram processados para parafina. Cortes longitudinais das cápsulas adjacentes aos implantes foram corados com H&E, tricrômico de Masson, Picrosirius e submetidos ao Alcian Blue (AB) e reações imuno-histoquímicas para IL-6 e FGF-1. Obteve-se a densidade numérica de células inflamatórias (CI), de células imunomarcadas para IL-6 e FGF-1 e de mastócitos AB-positivos, além da porcentagem de colágeno birrefringente. Os dados foram submetidos à ANOVA e teste Tukey (p≤0,05). O número de CI e de células imunomarcadas para IL-6 e FGF-1 foi significantemente maior aos 7 dias em todos os grupos. Diferenças significantes no número de células IL-6-positivas não foram observadas entre BDT e MTA aos 30 e 60 dias; aos 60 dias, diferenças significantes no número de CI também não foram detectadas. O número de células FGF-1- positivas foi significantemente maior no grupo BDT em comparação ao grupo MTA, em todos os períodos. A densidade numérica de mastócitos e a porcentagem de colágeno aumentaram significantemente ao longo do tempo. Aos 60 dias, o número de mastócitos e o conteúdo de colágeno foram significantemente maiores nos grupos BDT e MTA, respectivamente. A redução significante do processo inflamatório, concomitante à redução na imunoexpressão para IL-6, indica que ambos os materiais são biocompatíveis. A acentuada imunoexpressão de FGF-1 aos 7 dias sugere que este fator deve ser responsável, pelo menos em parte, pela proliferação de fibroblastos e, consequentemente, estimula a formação de colágeno nas cápsulas. Os mastócitos devem ter um papel importante na remodelação das cápsulas, pois uma forte correlação foi detectada entre o aumento significante de mastócitos e de colágeno.

Biodentine™ is a new calcium silicate-based biomaterial which presents improved physicochemical and biological properties compared to MTA. The aim of this study was to evaluate the tissue reaction promoted by Biodentine™ (BDT) and MTA Angelus White in rat subcutaneous. Adult rats were distributed into 3 groups (n=20/group) according to the implanted materials: BDT, MTA or CG (Control group; empty tubes). After 7, 15, 30 and 60 days, the implants and adjacent tissues were fixed and embedded in paraffin. Longitudinal sections of the capsule adjacent to implants were stained with H&E, Masson's trichrome, Picrosirius and submitted to Alcian Blue (AB). Immunohistochemical reactions for IL-6 and FGF-1 were also performed. The number of inflammatory cells (IC), IL-6 and FGF-1 immunolabeled cells, AB-positive mast cells as well as birefringent collagen percentage were obtained. Data were statistically analyzed by ANOVA and Tukey test (p≤0.05). The number of IC and IL-6 and FGF-1 immunolabeled cells were significantly high at 7 days in all groups. At 30 and 60 days, significant differences in the number of IL-6-positive cells were not detected between BDT and MTA. At 60 days, statistical difference in the IC number was not observed between BDT and MTA groups. In all periods, the number of FGF-1-positive cells was significant higher in BDT group in comparison to MTA. The numerical density of mast cells and collagen percentage increased over time. At 60 days, mast cells number and collagen content were significantly high in BDT and MTA groups, respectively. A significant reduction of inflammatory process and IL-6 immunoexpression indicates that both materials are biocompatible. Intense FGF-1 immunoexpression at 7 days suggests that this factor may be responsible, at least in part, for fibroblast proliferation and subsequent collagen formation in the capsules. Since a strong correlation between mast cells number and collagen density was detected, it is conceivable to suggest that mast cells play a pivotal role in the capsules remodeling