Effects of Foxp3 gene silencing on the expression of inflammatory cytokines and the proliferation and migration of human periodontal ligament fibroblasts in an inflammatory environment / 华西口腔医学杂志

OBJECTIVES@#This study aimed to clarify the effects of Foxp3 silencing on the expression of inflammatory cytokines in human periodontal ligament cells (hPDLFs) in an inflammatory environment and on cell proliferation and invasiveness, as well as to explore the role of Foxp3 gene in the development of periodontitis.@*METHODS@#An small interfering RNA (siRNA) construct specific for Foxp3 was transfected into hPDLFs. Foxp3 silencing efficiency was verified by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, and the siRNA with the optimum silencing effect of Foxp3 gene was screened. Using lipopolysaccharide to simulate an inflammatory environment in vitro, CCK-8 detected the effect of silencing Foxp3 on hPDLFs proliferation under inflammatory conditions. Wound-healing experiments and transwell assays were conducted to detect the effect of silencing Foxp3 on hPDLF migration under inflammatory conditions. The expression of the inflammatory cytokines interleukin (IL)-6 and IL-8 was detected by RT-PCR and Western blotting under inflammatory conditions.@*RESULTS@#After siRNA transfection, RT-PCR and Western blotting analyses showed that the expression of Foxp3 mRNA in the Foxp3-si3 group decreased significantly (t=21.03, P<0.000 1), and the protein expression of Foxp3 also decreased significantly (t=12.8, P<0.001). In the inflammatory environment, Foxp3 gene silencing had no significant effect on hPDLFs proliferation (P>0.05), and Foxp3 gene silencing promoted hPDLFs migration (P<0.05). Moreover, the expression of IL-6 and IL-8 increased (P<0.05).@*CONCLUSIONS@#In an inflammatory environment, Foxp3 gene silencing promoted hPDLFs migration but had no significant effect on hPDLFs proliferation. The expression of inflammatory factors expressed in hPDLFs increased after Foxp3 gene silencing, indicating that Foxp3 gene inhibited inflammation in periodontitis.

Hippo-YAP signaling pathway regulates autophagy of human periodontal ligament cells under cyclic tensile stress / 华西口腔医学杂志

OBJECTIVES@#This work aimed to investigate the molecular mechanism of cyclic tensile stress (CTS) stimulating autophagy in human periodontal ligament cells (hPDLCs).@*METHODS@#hPDLCs were isolated and cultured from normal periodontal tissues. hPDLCs were loaded with tensile stress by force four-point bending extender to simulate the autophagy of hPDLCs induced by orthodontic force du-ring orthodontic tooth movement. XMU-MP-1 was used to inhibit the Hippo signaling pathway to explore the role of the Hippo-YAP signaling pathway in activating hPDLC autophagy by tensile stress. The expression levels of autophagy-related genes (Beclin-1, LC3, and p62) in hPDLCs were detected by real-time quantitative polymerase chain reaction. Western blot was used to detect the expression levels of autophagy-related proteins (Beclin-1, LC3-Ⅱ/LC3-Ⅰ, and p62) and Hippo-YAP pathway proteins (active-YAP and p-YAP) in hPDLCs. Immunofluorescence was used to locate autophagy-related proteins (LC3-Ⅱand p62) and Hippo-YAP pathway proteins (active-YAP) of hPDLCs.@*RESULTS@#CTS-activated autophagy in hPDLCs and expression of autophagy-related proteins initially increased and then decreased; it began to increase at 30 min, peaked at 3 h, and decreased (P<0.05). CTS increased the expression of active-YAP protein and decreased the expression of p-YAP protein (P<0.05). When XMU-MP-1 inhibited the Hippo-YAP signaling pathway (P<0.05), active-YAP protein was promoted to enter the nucleus and autophagy expression was enhanced (P<0.05).@*CONCLUSIONS@#The Hippo-YAP signaling pathway is involved in the regulation of autophagy activation in hPDLCs under CTS.

Effect of naringenin on the anti-inflammatory, vascularization, and osteogenesis differentiation of human periodontal ligament stem cells via the stromal cell-derived factor 1/C-X-C motif chemokine receptor 4 signaling axis stimulated by lipopolysaccharide / 华西口腔医学杂志

OBJECTIVES@#This study aimed to investigate how naringenin (Nar) affected the anti-inflammatory, vascula-rization, and osteogenesis differentiation of human periodontal ligament stem cells (hPDLSCs) stimulated by lipopolysaccharide (LPS) and to preliminarily explore the underlying mechanism.@*METHODS@#Cell-counting kit-8 (CCK8), cell scratch test, and Transwell assay were used to investigate the proliferation and migratory capabilities of hPDLSCs. Alkaline phosphatase (ALP) staining, alizarin red staining, lumen-formation assay, enzyme-linked immunosorbent assay, quantitative timed polymerase chain reaction, and Western blot were used to measure the expression of osteopontin (OPN), Runt-related transcription factor 2 (RUNX2), vascular endothlial growth factor (VEGF), basic fibroblast growth factor (bFGF), von Willebrand factor (vWF), tumor necrosis factor-α (TNF-α), and interleukin (IL)-6.@*RESULTS@#We observed that 10 μmol/L Nar could attenuate the inflammatory response of hPDLSCs stimulated by 10 μg/mL LPS and promoted their proliferation, migration, and vascularization differentiation. Furthermore, 0.1 μmol/L Nar could effectively restore the osteogenic differentiation of inflammatory hPDLSCs. The effects of Nar's anti-inflammatory and promotion of osteogenic differentiation significantly decreased and inflammatory vascularization differentiation increased after adding AMD3100 (a specific CXCR4 inhibitor).@*CONCLUSIONS@#Nar demonstrated the ability to promote the anti-inflammatory, vascularization, and osteogenic effects of hPDLSCs stimulated by LPS, and the ability was associated with the stromal cell-derived factor/C-X-C motif chemokine receptor 4 signaling axis.

Study of the inflammatory activating process in the early stage of Fusobacterium nucleatum infected PDLSCs / 国际口腔科学杂志·英文版

Fusobacterium nucleatum (F. nucleatum) is an early pathogenic colonizer in periodontitis, but the host response to infection with this pathogen remains unclear. In this study, we built an F. nucleatum infectious model with human periodontal ligament stem cells (PDLSCs) and showed that F. nucleatum could inhibit proliferation, and facilitate apoptosis, ferroptosis, and inflammatory cytokine production in a dose-dependent manner. The F. nucleatum adhesin FadA acted as a proinflammatory virulence factor and increased the expression of interleukin(IL)-1β, IL-6 and IL-8. Further study showed that FadA could bind with PEBP1 to activate the Raf1-MAPK and IKK-NF-κB signaling pathways. Time-course RNA-sequencing analyses showed the cascade of gene activation process in PDLSCs with increasing durations of F. nucleatum infection. NFκB1 and NFκB2 upregulated after 3 h of F. nucleatum-infection, and the inflammatory-related genes in the NF-κB signaling pathway were serially elevated with time. Using computational drug repositioning analysis, we predicted and validated that two potential drugs (piperlongumine and fisetin) could attenuate the negative effects of F. nucleatum-infection. Collectively, this study unveils the potential pathogenic mechanisms of F. nucleatum and the host inflammatory response at the early stage of F. nucleatum infection.

Decreased phosphorylation of mitogen activated protein kinase and protein kinase B contribute to the inhibition of osteogenic differentiation mediated by activation of Toll like receptor in human periodontal ligament stem cells / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effects of Toll like receptors on the osteogenesis of human pe-riodontal ligament stem cells (hPDLSCs) and probable molecular mechanism.@*METHODS@#Real-time PCR and flow cytometry were applied to test the expression of TLRs in hPDLSCs and the positive cell percentage of TLR. hPDLSCs were cultured in osteogenic medium for 7 to 14 days with different TLR agonists at various concentrations . The effect of different TLR on osteogenic differentiation of hPDLSCs was evaluated by alizarin red S staining, alkaline phosphatase (ALP) staining and ALP activity assay. Western blotting was used to analyze the phosphorylation levels of extracellular regulated protein kinases (ERK), c-Jun N-terminal protein kinase (JNK), P38, AKT and expression of Runx2 an osteogenic related gene after treatment with TLR agonists, compared with the effect of inhibitors of mitogen activated protein kinase (MAPK) or protein kinase B (PKB or AKT) on Runx2 expression of hPDLSCs cultured in osteogenic medium.@*RESULTS@#Higher expressions of TLR1,3,4,6 were found in hPDLSCs through real-time PCR. Positive cell percentage of TLR was determined by flow cytometry and described as TLR1: 2.82%±0.68%; TLR2: 1.26%±0.09%; TLR3: 13.23%±2.05%; TLR4: 3.64%±0.79%; TLR6: 3.21%±1.64%, whose tendency was comparable to their mRNA expression in hPDLSCs. Most TLR ligands had no effect on the ALP staining, activity and mineralization of hPDLSCs at lower concentration except for 0.1 mg/L PolyI:C could induce the osteogenic ability of hPDLSCs. On the contrary, Higher concentration of TLR ligands (PolyI:C: 10 mg/L, LPS: 10 mg/L , Pam3CSK4: 1 mg/L, FSL-1: 50 μg/L) had obviously inhibitory effect on osteogenic differentiation of hPDLSCs. Activation of TLR using higher concentration of TLR ligands could downregulate the phosphorylation levels of ERK, P38, JNK and AKT, and also reduced the expression of Runx2, compared with the untreated control. The inhibitors of MAPK (U0126, SP600125,SB203580) and inhibitor of AKT (perifosine) could also inhibit Runx2 expression.@*CONCLUSION@#Higher concentration of TLR ligands could inhibit osteogenic differentiation of hPDLSCs. This inhibitory effect seemed to be related to decreased phosphorylation of MAPK and AKT.

Influence of vitamin D receptor FokI polymorphism on expression of CYP24A1 in periodontal cells / 北京大学学报(医学版)

OBJECTIVE@#There is asingle nucleotide polymorphism (SNP) in the exon 2 of the vitamin D receptor (VDR) gene that can be distinguished using the restriction endonuclease FokI, and accordingly divided into three genotypes: FF, Ff and ff. VDR-FokI polymorphism was the only known SNP that could alter the protein structure of VDR. CYP24A1 is the gene encoding vitamin D 24 hydroxylase and is a vitamin D responsive gene. The influence of rs2228570 on transcriptional activation by VDR in human gingival fibroblasts (hGF) and periodontal ligament cells (hPDLC) was investigated in this study.@*METHODS@#hGF and hPDLC of 12 donors' were primarily cultured and genomic DNA was extracted. A part of genomic DNA with the length of 267 bp was obtained using PCR, which contained the SNP. VDR-Fok I genotypes were determined according to the results of restriction fragment length polymorphism. hGF and hPDLC were stimulated with 10 nmol/L 1α,25 dihydroxy vitamin D3 (1,25OH2D3) or 1 000 nmol/L 25 hydroxy vitamin D3 (25OHD3) for 48 h before RNA was extracted. Then VDR antagonist ZK159222 was used or not used during 1,25OH2D3 or 25OHD3 stimulation with hGF and hPDLC. After 1,25OH2D3 stimulation for 48 h, the proteins in hGF and hPDLC were also collected. The protein expressions of CYP24A1 and VDR were detected using Western blot.@*RESULTS@#Among the 12 donors' cell cultures, the number of FF, ff and Ff genotypes was 4, 3 and 5, respectively.After stimulation with 1,25OH2D3 or 25OHD3 for 48 h,CYP24A1 mRNA levels in FF-hGF were significantly higher than those in other hGF genotypes(1,25OH2D3: F=31.147, P<0.01; 25OHD3: F= 32.061,P <0.01), as was in FF-hPDLC (1,25OH2D3: F=23.347, P<0.01; 25OHD3: F=32.569,P<0.01). When ZK159222 was used before 1,25OH2D3 stimulation, this statistically significant difference disappeared (hGF: F=0.246, P=0.787; hPDLC: F=0.574, P=0.583). When ZK159222 was used before 25OHD3 stimulation, the trend was similar (hGF: F=1.636, P=0.248; hPDLC: F=0.582, P=0.578).After stimulation with 1,25OH2D3 for 48 h, CYP24A1 protein levels in FF-hGF were significantly higher than those in the other hGF genotypes (F=12.368, P <0.01), as was in FF-hPDLC (F=15.749, P <0.01). In hGF and hPDLC, the mRNA or protein expression of VDR of different genotypes was not significantly different under different stimulation conditions.The paired comparison showed that there was no statistically significant difference between the expression of CYP24A1 in hGF and that in hPDLC under all the stimulation conditions, as was the expression of VDR.@*CONCLUSION@#In hGF and hPDLC, the FF-VDR genotype is associated with the more remarkable up-regulation of CYP24A1than the other genotypes, indicating that transcriptional activation of FF-VDR might be higher than those of other vitamin D receptors.

Topical application of bFGF on acid-conditioned and non-conditioned dentin: effect on cell proliferation and gene expression in cells relevant for periodontal regeneration

Abstract Periodontal regeneration is still a challenge in terms of predictability and magnitude of effect. In this study we assess the biological effects of combining chemical root conditioning and biological mediators on three relevant cell types for periodontal regeneration. Material and Methods: Bovine dentin slices were conditioned with 25% citric acid followed by topical application of basic fibroblast growth factor (bFGF, 10 and 50 ng). We used ELISA to assess the dynamics of bFGF release from the dentin surface and RT-qPCR to study the expression of Runx2, Col1a1, Bglap and fibronectin by periodontal ligament (PDL) fibroblasts, cementoblasts and bone marrow stromal cells (BMSC) grown onto these dentin slices. We also assessed the effects of topical application of bFGF on cell proliferation by quantification of genomic DNA. Results: Acid conditioning significantly increased the release of bFGF from dentin slices. Overall, bFGF application significantly (p<0.05) increased cell proliferation, except for BMSC grown on non-conditioned dentin slices. Dentin substrate discretely increased expression of Col1a1 in all cell types. Expression of Runx2, Col1a1 and Fn was either unaffected or inhibited by bFGF application in all cell types. We could not detect expression of the target genes on BMSC grown onto conditioned dentin. Conclusion: Acid conditioning of dentin improves the release of topically-applied bFGF. Topical application of bFGF had a stimulatory effect on proliferation of PDL fibroblasts, cementoblasts and BMSC, but did not affect expression of Runx2, Col1a1, Bglap and fibronectin by these cells.

Estudo da expressão e produção de componentes do sistema renina-angiotensina por fibroblastos de gengiva e ligamento periodontal humanos / Study of expression and production of the renin-angiotensin system components by gingival and periodontal ligament human fibroblasts

O Sistema Renina-angiotensina (SRA), e um sistema capaz de gerar hormonios peptideos com grande impacto na regulacao cardiovascular e na patogenese das doencas cardiovasculares. Este sistema opera, por meio das acoes da Angiotensina II, tanto em nivel sistemico (endocrino) quanto tecidual (local, paracrino/autocrino) controlando importantes funcoes, varias delas relacionadas a facilitacao da instalacao e progressao do processo inflamatorio. Por este motivo, a producao desta proteina nos tecidos pode estar relacionada a patogenese de muitas doencas, dentre elas a doenca periodontal (DP), tendo em vista seu carater infeccioso-inflamatorio e os achados da literatura que mostram que a inibicao da formacao de Ang II, diminui a perda óssea da DP em animais. Desta forma, o presente trabalho teve como objetivos: Avaliar in vitro, a) A expressao de componentes do SRA (ANGT, RENINA, ECA, ECA-2, AT1, AT2 e Mas) por fibroblastos de gengiva e ligamento periodontal humanos, por RT-qPCR; b) A producao de componentes do SRA (RENINA, ECA, ECA-2) no sobrenadante de culturas de fibroblastos de gengiva e ligamento periodontal humanos, por ELISA; c) A producao dos receptores do SRA (AT1, AT2 e Mas), nestes fibroblastos, por Imunofluorescencia e d) Se a expressao e a producao dos componentes do SRA por fibroblastos de gengiva e ligamento periodontal humanos, se alteram com a estimulacao por LPS de P. gingivalis e E. coli. Apos a coleta, os dados foram analisados com o auxilio do programa GraphPad Prism 5.0. por meio da analise de variancia a 2 criterios (ANOVA-two way) seguida do pos teste de Bonferroni, com nivel de significancia de 5% para a verificacao das possíveis diferencas. Foi detectada a expressao genica para alguns dos componentes do SRA (ANGT, RENINA, ECA, AT1) por fibroblastos tanto de gengiva quanto de ligamento periodontal. Foi detectada ainda uma expressao genica diferenciada entre fibroblastos de gengiva e ligamento periodontal para...

The Renin-angiotensin system (RAS) can generate hormones that have a high-impact on cardiovascular regulation as well as in the pathogenesis of cardiovascular disease. This system acts through both systemic (endocrine) and local (paracrine/autocrine) effects of Angiotensin II, controlling important functions related to the facilitation of installation and progression of the inflammatory process. For this reason, this proteins production in tissues can be associated to the pathogenesis of many diseases, including periodontal disease (PD). In the PD setting, a infectious-inflammatory characterized disease, the literature findings shows that inhibition of the Ang II formation can decrease the bone loss in animals. In this context, the aims of the present study were: to investigate in vitro: a) the expression of RAS components (ANGT, RENIN, ECA, ECA- 2, AT1, AT2 and Mas) by human gingival and periodontal ligament fibroblasts by RT-qPCR; b) the production of RAS receptors (AT1, AT2 and Mas) by human cultured gingival and periodontal ligament fibroblasts by Immunofluorescence and d) the production of RAS components (RENIN, ECA, ECA-2) if the expression and production of RAS components by gingival and periodontal ligament fibroblasts modify under P. gingivalis and E. coli LPS stimulation. After collected, the data were analysed using GraphPad Prism 5.0, by the two way ANOVA followed by Bonferroni post test with a significance level of 5%. Gene expression was detected for some of the RAS components (ANGT, RENIN, ECA, AT1) by both gingival and periodontal ligament fibroblasts. It was detected a differential gene expression between gingival and periodontal ligament fibroblasts for ECA, being significantly higher in gingival fibroblasts. There was a stain in Immunofluorescence compatible with the production of RAS receptors (AT1 and Mas). It must be noted that the...

Estudo da expressão e produção de componentes do sistema renina-angiotensina por fibroblastos de gengiva e ligamento periodontal humanos / Study of expression and production of the renin-angiotensin system components by gingival and periodontal ligament human fibroblasts

O Sistema Renina-angiotensina (SRA), e um sistema capaz de gerar hormonios peptideos com grande impacto na regulacao cardiovascular e na patogenese das doencas cardiovasculares. Este sistema opera, por meio das acoes da Angiotensina II, tanto em nivel sistemico (endocrino) quanto tecidual (local, paracrino/autocrino) controlando importantes funcoes, varias delas relacionadas a facilitacao da instalacao e progressao do processo inflamatorio. Por este motivo, a producao desta proteina nos tecidos pode estar relacionada a patogenese de muitas doencas, dentre elas a doenca periodontal (DP), tendo em vista seu carater infeccioso-inflamatorio e os achados da literatura que mostram que a inibicao da formacao de Ang II, diminui a perda óssea da DP em animais. Desta forma, o presente trabalho teve como objetivos: Avaliar in vitro, a) A expressao de componentes do SRA (ANGT, RENINA, ECA, ECA-2, AT1, AT2 e Mas) por fibroblastos de gengiva e ligamento periodontal humanos, por RT-qPCR; b) A producao de componentes do SRA (RENINA, ECA, ECA-2) no sobrenadante de culturas de fibroblastos de gengiva e ligamento periodontal humanos, por ELISA; c) A producao dos receptores do SRA (AT1, AT2 e Mas), nestes fibroblastos, por Imunofluorescencia e d) Se a expressao e a producao dos componentes do SRA por fibroblastos de gengiva e ligamento periodontal humanos, se alteram com a estimulacao por LPS de P. gingivalis e E. coli. Apos a coleta, os dados foram analisados com o auxilio do programa GraphPad Prism 5.0. por meio da analise de variancia a 2 criterios (ANOVA-two way) seguida do pos teste de Bonferroni, com nivel de significancia de 5% para a verificacao das possíveis diferencas. Foi detectada a expressao genica para alguns dos componentes do SRA (ANGT, RENINA, ECA, AT1) por fibroblastos tanto de gengiva quanto de ligamento periodontal. Foi detectada ainda uma expressao genica diferenciada entre fibroblastos de gengiva e ligamento periodontal para...

The Renin-angiotensin system (RAS) can generate hormones that have a high-impact on cardiovascular regulation as well as in the pathogenesis of cardiovascular disease. This system acts through both systemic (endocrine) and local (paracrine/autocrine) effects of Angiotensin II, controlling important functions related to the facilitation of installation and progression of the inflammatory process. For this reason, this proteins production in tissues can be associated to the pathogenesis of many diseases, including periodontal disease (PD). In the PD setting, a infectious-inflammatory characterized disease, the literature findings shows that inhibition of the Ang II formation can decrease the bone loss in animals. In this context, the aims of the present study were: to investigate in vitro: a) the expression of RAS components (ANGT, RENIN, ECA, ECA- 2, AT1, AT2 and Mas) by human gingival and periodontal ligament fibroblasts by RT-qPCR; b) the production of RAS receptors (AT1, AT2 and Mas) by human cultured gingival and periodontal ligament fibroblasts by Immunofluorescence and d) the production of RAS components (RENIN, ECA, ECA-2) if the expression and production of RAS components by gingival and periodontal ligament fibroblasts modify under P. gingivalis and E. coli LPS stimulation. After collected, the data were analysed using GraphPad Prism 5.0, by the two way ANOVA followed by Bonferroni post test with a significance level of 5%. Gene expression was detected for some of the RAS components (ANGT, RENIN, ECA, AT1) by both gingival and periodontal ligament fibroblasts. It was detected a differential gene expression between gingival and periodontal ligament fibroblasts for ECA, being significantly higher in gingival fibroblasts. There was a stain in Immunofluorescence compatible with the production of RAS receptors (AT1 and Mas). It must be noted that the...

Periodontal ligament and gingival fibroblasts participate in the production of TGF-β, interleukin (IL)-8 and IL-10

The aim of this study was to quantify and compare the production of transforming growth factor beta (TGF-β), interleukin (IL)-8 and IL-10 by human cultured periodontal ligament and gingival fibroblasts both obtained from the same donors challenged with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Fibroblasts were exposed to 0.1-10 µg/mL of LPS from P. gingivalis and after 24 h the supernatants were collected and analyzed by enzyme-linked immunosorbent assay (ELISA). TGF-β protein production was upregulated in a concentration-dependent manner, mainly in gingival fibroblasts, which was statistically significant when challenged by 10 µg/mL LPS. Additionally, at this concentration, gingival fibroblasts had almost a two-fold increase in the amount of TGF-β when compared to periodontal ligament fibroblasts. Both periodontal ligament and gingival fibroblasts showed an increase in IL-8 production when challenged with 1 µg/mL and 10 µg/mL LPS. IL-10 production remained unaffected when challenged by any of the LPS concentrations tested in either periodontal ligament or gingival fibroblasts. Our results demonstrate that periodontal ligament and gingival fibroblasts when challenged by LPS from P. gingivalis with 24 h may play a critical role in producing TGF-β and IL-8 but not IL-10.

Bisfosfonato e movimentaçäo dentária induzida: avaliaçäo microscópica de seus efeitos / Biophosphonates and induced tooth movement: microscopical evaluation of its effects

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

Avaliaçäo macro e microscópica dos primeiros momentos da movimentaçäo dentária induzida em macacos da espécie Cebus apella / Macroscopical and microscopical evaluation of early moments of tooth movement induced in monkeys Cebus apella

Avaliou-se morfológica e quantitativamente, do ponto de vista macro e microscópico, os primeiros momentos da movimentaçäo dentária induzida em macacos da espécie Cebus apella. Foram analisados quantitativamente o movimento dentário e as áreas de pressäo e tensäo dos terços cervicais do ligamento periodontal. A força empregada foi aproximadamente de 3 onças, correspondente a 84 gramas, de forma contínua dissipante e contínua dissipante com períodos de repouso, ou seja intermitente. Para as condiçöes de força contínua dissipante analisou-se a movimentaçäo dentária no final de 5, 10, 15 e 20 horas. Na situaçäo de força contínua dissipante, mas intermitente, os períodos avaliados foram de 10hF/5hR, 10hF/10hR, 10hF/5hR e 10hF/5hR/10hF. Com base na metodologia adotada e considerando as limitaçöes inerentes, os resultados obtidos neste estudo permitiram verificar que: 1) Quanto à movimentaçäo dentária: 1.1) a movimentaçäo dentária induzida atingiu seu ponto máximo após 10 horas de força contínua dissipante; 1.2) nos períodos de 10, 15 e 20 horas as movimentaçöes dentárias médias näo apresentaram diferenças estatisticamente significantes...