CXXC5 mitigates P. gingivalis-inhibited cementogenesis by influencing mitochondrial biogenesis.

BACKGROUND: Cementoblasts on the tooth-root surface are responsible for cementum formation (cementogenesis) and sensitive to Porphyromonas gingivalis stimulation. We have previously proved transcription factor CXXC-type zinc finger protein 5 (CXXC5) participates in cementogenesis. Here, we aimed to elucidate the mechanism in which CXXC5 regulates P. gingivalis-inhibited cementogenesis from the perspective of mitochondrial biogenesis. METHODS: In vivo, periapical lesions were induced in mouse mandibular first molars by pulp exposure, and P. gingivalis was applied into the root canals. In vitro, a cementoblast cell line (OCCM-30) was induced cementogenesis and submitted for RNA sequencing. These cells were co-cultured with P. gingivalis and examined for osteogenic ability and mitochondrial biogenesis. Cells with stable CXXC5 overexpression were constructed by lentivirus transduction, and PGC-1α (central inducer of mitochondrial biogenesis) was down-regulated by siRNA transfection. RESULTS: Periapical lesions were enlarged, and PGC-1α expression was reduced by P. gingivalis treatment. Upon apical inflammation, Cxxc5 expression decreased with Il-6 upregulation. RNA sequencing showed enhanced expression of osteogenic markers, Cxxc5, and mitochondrial biogenesis markers during cementogenesis. P. gingivalis suppressed osteogenic capacities, mitochondrial biogenesis markers, mitochondrial (mt)DNA copy number, and cellular ATP content of cementoblasts, whereas CXXC5 overexpression rescued these effects. PGC-1α knockdown dramatically impaired cementoblast differentiation, confirming the role of mitochondrial biogenesis on cementogenesis. CONCLUSIONS: CXXC5 is a P. gingivalis-sensitive transcription factor that positively regulates cementogenesis by influencing PGC-1α-dependent mitochondrial biogenesis. Video Abstract.

Periodontal tissue regeneration with cementogenesis after application of brain-derived neurotrophic factor in 3-wall inflamed intra-bony defect.

OBJECTIVE: The purpose of this study is to investigate regenerative process by immunohistochemical analysis and evaluate periodontal tissue regeneration following a topical application of BDNF to inflamed 3-wall intra-bony defects. BACKGROUND: Brain-derived neurotrophic factor (BDNF) plays a role in the survival and differentiation of central and peripheral neurons. BDNF can regulate the functions of non-neural cells, osteoblasts, periodontal ligament cells, endothelial cells, as well as neural cells. Our previous study showed that a topical application of BDNF enhances periodontal tissue regeneration in experimental periodontal defects of dog and that BDNF stimulates the expression of bone (cementum)-related proteins and proliferation of human periodontal ligament cells. METHODS: Six weeks after extraction of mandibular first and third premolars, 3-wall intra-bony defects were created in mandibular second and fourth premolars of beagle dogs. Impression material was placed in all of the artificial defects to induce inflammation. Two weeks after the first operation, BDNF (25 and 50 µg/mL) immersed into atelocollagen sponge was applied to the defects. As a control, only atelocollagen sponge immersed in saline was applied. Two and four weeks after the BDNF application, morphometric analysis was performed. Localizations of osteopontin (OPN) and proliferating cell nuclear antigen (PCNA)-positive cells were evaluated by immunohistochemical analysis. RESULTS: Two weeks after application of BDNF, periodontal tissue was partially regenerated. Immunohistochemical analyses revealed that cells on the denuded root surface were positive with OPN and PCNA. PCNA-positive cells were also detected in the soft connective tissue of regenerating periodontal tissue. Four weeks after application of BDNF, the periodontal defects were regenerated with cementum, periodontal ligament, and alveolar bone. Along the root surface, abundant OPN-positive cells were observed. Morphometric analyses revealed that percentage of new cementum length and percentage of new bone area of experimental groups were higher than control group and dose-dependently increased. CONCLUSION: These findings suggest that BDNF could induce cementum regeneration in early regenerative phase by stimulating proliferation of periodontal ligament cells and differentiation into periodontal tissue cells, resulting in enhancement of periodontal tissue regeneration in inflamed 3-wall intra-bony defects.

PTX3 promotes cementum formation and cementoblast differentiation via HA/ITGB1/FAK/YAP1 signaling pathway.

Cementum is a vital component of periodontium, yet its regeneration remains a challenge. Pentraxin 3 (PTX3) is a multifunctional glycoprotein involved in extracellular matrix remodeling and bone metabolism regulation. However, the role of PTX3 in cementum formation and cementoblast differentiation has not been elucidated. In this study, we initially observed an increase in PTX3 expression during cementum formation and cementoblast differentiation. Then, overexpression of PTX3 significantly enhanced the differentiation ability of cementoblasts. While conversely, PTX3 knockdown exerted an inhibitory effect. Moreover, in Ptx3-deficient mice, we found that cementum formation was hampered. Furthermore, we confirmed the presence of PTX3 within the hyaluronan (HA) matrix, thereby activating the ITGB1/FAK/YAP1 signaling pathway. Notably, inhibiting any component of this signaling pathway partially reduced the ability of PTX3 to promote cementoblast differentiation. In conclusion, our study indicated that PTX3 promotes cementum formation and cementoblast differentiation, which is partially dependent on the HA/ITGB1/FAK/YAP1 signaling pathway. This research will contribute to our understanding of cementum regeneration after destruction.

Premixed calcium silicate-based ceramic sealers promote osteogenic/cementogenic differentiation of human periodontal ligament stem cells: A microscopy study.

To evaluate the effects of premixed calcium silicate based ceramic sealers on the viability and osteogenic/cementogenic differentiation of human periodontal ligament stem cells (hPDLSCs). The materials evaluated were TotalFill BC Sealer (TFbc), AH Plus Bioceramic Sealer (AHPbc), and Neosealer Flo (Neo). Standardized discs and 1:1, 1:2, and 1:4 eluates of the tested materials were prepared. The following in vitro experiments were carried out: ion release, cell metabolic activity 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell migration, immunofluorescence experiment, cell attachment, gene expression, and mineralization assay. Statistical analyses were performed using one-way ANOVA followed by Tukey's post hoc test (p < .05). Increased Ca2+ release was detected in TFbc compared to AHPbc and Neo (*p < .05). Biological assays showed a discrete cell metabolic activity and cell migration in Neo-treated cell, whereas scanning electronic microscopy assay exhibited that TFbc group had a better cell adhesion process of substrate attachment, spreading, and cytoskeleton development on the niche-like structures of the cement than AHPbc and Neo. The sealers tested were able to induce overexpression of the CEMP-1, ALP, and COL1A1 genes in the first days of exposure, particularly in the case of TFbc (***p < .001). All materials tested significantly increased the mineralization of hPDLSCs when compared to the negative control, although more pronounced calcium deposition was observed in the TFbc-treated cells (***p < .001). Our results suggested that TFbc promotes cell differentiation, both by increasing the expression of key osteo/odontogenic genes and by promoting mineralization of the extracellular matrix, whereas this phenomenon was less evident in Neo and AHPbc. RESEARCH HIGHLIGHTS: TFbc group had a better cell adhesion process of substrate attachment, spreading, and cytoskeleton development on the niche-like structures of the cement than AHPbc and Neo. The sealers tested were able to induce overexpression of the CEMP-1, ALP, and COL1A1 genes in the first days of exposure, particularly in the case of TFbc. All materials tested significantly increased the mineralization of hPDLSCs when compared to the negative control, although more pronounced calcium deposition was observed in the TFbc-treated cells.

Cemento dental: aspectos atuais de interesse para o clínico / Dental cementum: current aspects to the clinicians

Embora tenha havido avanço no entendimento da homeostase do cemento dental, o papel deste tecido e sua biologia permanecem não completamente elucidados. Este estudo buscou fornecer informações sobre os conhecimentos mais recente relacionados à biologia do cemento dental, com o objetivo de discutir o papel exercido por este tecido em condições não fisiológicas nos tecidos periodontais. Devido aos avanços na exploração do tecido ósseo, que compartilha diversas características similares, a pesquisa abrangente sobre o cemento dental tem sido encorajada, a fim de esclarecer a função completa deste tecido na homeostase periodontal e regeneração. Desta forma, no presente trabalho, sempre que possível será feito um paralelo entre osso alveolar e cemento dental. O desenvolvimento de metodologias e técnicas celulares e moleculares avançadas possibilitou um melhor entendimento do comportamento do cemento em situações diversas, como quando em situações patológicas, como a doença periodontal, e até mesmo frente à regeneração tecidual. Ademais, estudos clínicos e em modelo animal demonstraram resultados em relação à formação de cemento em abordagens regenerativas. No entanto, sugere-se que estudos posteriores possam contribuir para um melhor conhecimento sobre o cemento e o perfil celular dos cementoblastos e cementócitos, bem como suas interações para fornecer novos insights para o desenvolvimento de terapias eficientes e mais previsíveis para regeneração dos tecidos periodontais. Apesar dos avanços dos estudos clínicos e laboratoriais, pôde-se concluir que inúmeras questões referentes à biologia do cemento permanecem não esclarecidas.

Although some progress has been made to understand dental cementum homeostasis, its role and biology remains not completely elucidated. This study aimed to provide information on the recent knowledge related to the dental cementum biology, in order to discuss the role of this tissue in physiological and non-physiological conditions in the periodontal tissues. Due to advances in the exploration of bone tissue, which shares several similar features, comprehensive research on dental cementum has been encouraged in order to clarify the complete function of this tissue in periodontal homeostasis and regenerative approach. Novel methodologies and advanced cellular and molecular techniques provided better understanding of cementum in different circumstances, as pathological situations such as periodontal disease and even tissue regeneration. In addition, clinical and animal model designs show positive outcomes to cementum formation in regenerative approaches, however, it is suggested that further studies may contribute to better understand cementum tissue and cementoblasts and cementocytes profile, as well as their interactions, providing new insights to develop efficient and more predictable therapies for periodontal tissue regeneration. Despite advances in clinical and laboratory studies, it can be concluded that many questions regarding the cementum biology remain unclear.

Cyclosporin a-induced new cementum formation: a morphometric evaluation in the periapical region of rats

Cyclosporin A (CsA) is a potent immunosuppressor used in organ transplantation and in the management of various autoimmune diseases. Recent studies have shown that CsA stimulates deposition of cementum on root surfaces. The aim of this study was to evaluate the periapical cementum thickness and the apical foramen width in CsA-treated rats. Rats weighing 50 g were treated with a daily injection of 10 mg/kg body weight of CsA in the chow for 60 days. The cementum of the mandibular 1st molars was histologically and morphometricaly examined by analysis of 5-æm-thick serial buccolingual paraffin sections stained with hematoxylin and eosin. Histometric and stereologic analyses revealed the presence of large amounts of cementum in all root surfaces, particularly abundant in the periapical region and obliterating the foramen. The volume density of cementoblasts did not increase. Five to 90 days after the termination of CsA therapy, there was no reduction of cementum thickness. These results suggest that cementum deposition is not reversible after cessation of CsA treatment.

Ciclosporina A (CsA) é um potente imunossupressor usado no transplante de órgãos e no tratamento de várias doenças auto-imunes. Recentes estudos têm demonstrado que a CsA estimula a deposição de cemento na superfície radicular. O objetivo deste estudo foi de avaliar a espessura do cemento periapical e largura do forame apical em ratos tratados com CsA. Os ratos pesavam 50 g e foram tratados com doses diárias de 10 mg/kg de peso corporal de CsA no período de 60 dias. O cemento do primeiro molar inferior foi examinado histologicamente e morfometricamente por análises de cortes em parafina com 5æm de espessura no sentido vestíbulo-lingual e corados com hematoxilina e eosina. As análises histométricas e estereológicas revelaram a presença de largos depósitos de cemento em todas as superfícies radiculares, particularmente maior na região periapical e obliterando o forame. A densidade volumétrica dos cementoblastos não foi aumentada. No período de 5 a 90 dias após o término da terapia com CsA, não houve redução na espessura do cemento. Estes resultados sugerem que o depósito de cemento não é reversível após o tratamento com CsA ser cessado.

Ultra-structure characterization of self-etching treated cementum surfaces

Objectives: to evaluate the effect of different conditioning treatments on surface roughness and topography ofdental cementum. Study Design: Extracted human canines were used for the present study. The mesial surfacefrom the cervical third of the roots were ground flat with wet 600-grit silicon carbide paper. They were polished(up to 1/4 μm diamond paste) and treated as follows: 1) No treatment, 2) 35% H3PO4 during 15 s, 3) Clearfil SEBond primer (SEB), 4) One-Up Bond F (OUB). The adhesive systems were applied following manufacturer’s instructions.SEB primer and OUB were removed from surfaces by washing and ultrasonic agitation with ascendingethanol solutions. Digital images of treated surfaces (5x5 and 15x15 μm) were obtained by means of an atomicforce microscope (AFM) analysis. The average surface roughness (Ra nanometers) of the scanned areas was assessed.Data were analyzed by ANOVA and SNK multiple comparisons tests (p<0.05). Results: phosphoric acidtreatment produced the highest mean roughness value, at all scan sizes. At 5x5 μm AFM images, for self-etchadhesive systems no differences in roughness were detected. At 15x15 μm, when One-Up Bond F was employedthe lowest value was obtained. Conclusions: When phosphoric acid treatment was applied, cementum surfaceroughness increased and a strong demineralization with exposed collagen fibers could be observed (AU)

Los cementos ionómeros de vidrio y el mineral trióxido agregado como materiales biocompatibles usados en la proximidad del periodonto / Glass ionomer cements and the mineral trioxide aggregate (MTA) as biocompatible materials used in the periodontal proximity

El artículo revisa la composición química, biocompatibilidad, usos clínicos, estudios in vivo e in vitro de los cementos ionómeros de vidrio (CIVs) y el mineral trióxido agregado (MTA). Deja establecida la vigencia de los dos materiales y la controversia de establecer cual de los dos materiales sería mejor usar en los tratamientos donde los fibroblastos del ligamento periodontal y los osteoblastos entran en función.

Healing process of dog teeth after post space preparation and exposition of the filling material to the oral environment

The purpose of this study was to observe the influence of coronal leakage on the behavior of periapical tissues after root canal filling and post space preparation. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta percha points and the cements Sealer 26 and Roth. After post space preparation, the remaining filling material was either protected or not protected with a plug of the temporary cement Lumicon. After root canal exposition to the oral environment for 90 days, the animals were killed and specimens were removed and prepared for histomorphological analysis. The Brown and Brenn technique showed 70 percent of cases with microorganism leakage for Roth cement, and 20 percent with Sealer 26. When a plug of Lumicon was employed, there was 30 percent leakage for Roth cement and 0 percent for Sealer 26. A chronic inflammatory reaction was more frequently observed with Roth cement than with Sealer 26. It was concluded that a plug of Lumicon was efficient in controlling microorganism coronal leakage (p=0.05), and that Sealer 26 was more biocompatible and sealed root canals better than Roth sealer (p=0.01)