Elizabeth Ferreira Martinez

Root canal sealers should provide effective sealing while remaining biocompatible with periapical tissues. Strategies to further improve their biological performance are desirable. Resveratrol, a bioactive polyphenol with antioxidant and regenerative properties, may enhance cellular responses and tissue repair, representing a promising adjunct for endodontic materials. Aim: The aim of this study was to evaluate cell viability and type I collagen expression in undifferentiated mesenchymal stem cell cultures exposed to EndoSequence BC bioceramic or AH Plus resin-based endodontic cements, with or without the addition of resveratrol. Materials and Method: Cement specimens were prepared in standardized molds (5 mm × 2 mm), allowed to set for 48 hours, sterilized, and conditioned in culture medium at a concentration of 0.2 g/mL at 37 °C. Resveratrol was added to the culture media at concentrations of 0.25 μM and 0.5 μM. The mesenchymal cell cultures were exposed to the different experimental conditions for 24, 48 and 72 hours, after which viability was assessed by MTT assay, and type I collagen secretion was quantified using the enzyme-linked immunosorbent assay (ELISA). Results: EndoSequence BC demonstrated significantly greater cell viability than AH Plus (p<0.05). At 48 hours, AH Plus combined with 0.5 μM resveratrol showed significantly greater cell viability than the cement alone and the 0.25 μM resveratrol group (p<0.05). In addition, supplementation with 0.5 μM resveratrol significantly increased type I collagen secretion for both cements compared to the corresponding groups without resveratrol (p<0.05), indicating a positive effect on extracellular matrix production. Conclusions: These findings suggest that resveratrol is a promising additive for improving the bioactivity of endodontic cements, enhancing collagen production and potentially contributing to tissue regeneration and bone repair.

This study aimed to evaluate periosteum-derived mesenchymal stem cells (P-MSCs) cultured under simulated microgravity (SMG) conditions. P-MSCs were induced toward osteogenic differentiation and then exposed to SMG for up to 48 h. As a control, P-MSCs were maintained under identical conditions but without SMG exposure. Cell viability, osteogenesis-related analytes, and gene expression were analyzed at 3, 24 and 48 h. Cell viability under SMG was lower after 3 h but was significantly higher after 24 h, with no difference at 48 h. There was a higher expression of pathways associated with inflammation at 3 h, which was attenuated by 24 h and neutralized at 48 h. P-MSCs under SMG demonstrated three characteristics in at least one timepoint, which supports a pro-osteogenic signaling response: (1) higher osteoprotegerin levels; (2) lower DKK1 and TNF levels; (3) upregulation of genes related to osteogenesis. Our data suggest that P-MSCs exhibit enhanced pro-osteogenic regulatory modulation in SMG.

Objective: To compare biochemical characteristics of blood samples obtained from dif-ferent anatomical sites: mandibular bone marrow, iliac bone marrow, and peripheral blood. Methods: This study included 26 patients undergoing dental implant placement and maxillary reconstruction with iliac bone grafting. Blood samples were collected from mandibular bone marrow, iliac bone marrow, and peripheral venous blood. Gasometric analysis evaluated PCO₂, PO₂, TCO₂, oxygen saturation (SatO₂), ionized calcium, pH, lactate, and magnesium. Statistical analysis included the Shapiro-Wilk test, repeated measures ANOVA with Bonferroni post hoc, and the Friedman test with Wilcoxon comparisons (p < 0.05). Results: Mandibular bone marrow blood showed significantly higher pH, PO₂, and oxygen saturation, and lower PCO₂ and HCO₃⁻ compared to other sites. These findings indicate a more oxygenated and less acidic microenvironment. No significant differences were observed for lactate, magnesium, and ionized calcium. Conclusion: Mandibular bone marrow exhibits a more favorable biochemical profile for osteogenic metabolism, suggesting its potential advantage for bone graft integration and autologous blood derivatives.

Endodontic treatment offers a high success rate; however, the search for therapeutic alternatives that promote regeneration of the dentin-pulp complex has elicited great interest. Aim: The aim of this study was to evaluate, in an in vivo model, the potential for dentin-pulp regeneration by transplantation of stem cells from two sources: pulp of human deciduous teeth and periosteum. Materials and Method: Eighteen mesiobuccal canals of maxillary first molars of immunosuppressed rats were distributed into three groups (n=6): group DT (deciduous teeth pulp), received stem cells from deciduous tooth pulp in hydrogel vehicle; group P (periosteal), received periosteal stem cells in hydrogel vehicle; and group NC (negative control) received only hydrogel. After pulpectomy and canal preparation, the teeth received the respective materials, and the cavities were sealed. After 12 weeks, the animals were euthanized and the specimens underwent histological processing and qualitative evaluation of intracanal fibrous connective tissue, odontoblast-like cells, intracanal mineralized tissue, and inflammatory cell infiltrate. Results: In the NC group, abundant presence of inflammatory cells was observed throughout the canal, in addition to dentin chips and remnants of amorphous substance from pulp tissue. In groups DT and P, in the apical region, new tissue formation suggestive of repair was observed, with deposition of bone-like mineralized tissue and periodontal ligament-like connective tissue containing blood vessels and osteocyte- and fibroblast-like cells. Conclusions: Transplanted stem cells from pulp of human deciduous teeth and periosteum did not show potential for regeneration, but for tissue repair, with formation of periodontal ligament-like and bone-like tissue.

Gingival biotype is decisive for the outcome of rehabilitation treatments, and its impact on therapeutic prognosis is directly related to tissue fragility and marginal tissue recessions. This study aimed to evaluate the effect of enamel matrix derivative (EMD) and porcine collagen matrix, alone or combined, on wounds made on the rat dorsum. Wounds were created in the dorsum of 40 Wistar rats divided into 4 sample groups: G1 = clot, G2 = porcine collagen matrix (Straumann ^® Mucoderm ^® ), G3 = enamel matrix derivative (EMD, Emdogain ^® ), G4 = porcine collagen matrix (Straumann ^® Mucoderm ^® ) and EMD (Emdogain ^® ). The animals were euthanized on days 7 and 14, and their wound was evaluated histologically to assess wound closure and re-epithelialization, and to measure tissue inflammation. At 7 days, groups treated with EMD (G3 and G4) exhibited significantly lower inflammation scores compared to G1 and G2 ( p < 0.05). At 14 days, all groups showed complete wound closure with no significant differences in inflammatory scores. However, G3 demonstrated a markedly greater epithelial thickness, with epithelial projections into the underlying connective tissue and evidence of keratin formation. Collagen fiber organization was also more evident in G3 and G4. Therefore, porcine collagen matrix, whether alone or combined, promoted tissue regeneration, and the combination of these substitutes with EMD, resulted in less tissue inflammation and greater epithelial thickness. These advantages emphasize their use for soft tissue augmentation and improvement.

AIM. This study investigated the impact of calcium silicate sealers on bone healing in rat calvaria defects.MATERIALS AND METHODS. Twenty-six rats were divided into 3 groups. Calvaria defects were prepared and treated in 3 different ways: CG (n = 6): Filling with clot; ES (n = 10): Filling with Endosequence BC RRM Putty repair sealer and BC (n = 10): Filling with Bio C repair sealer.RESULTS. After 15 and 30 days, histological evaluations revealed varied levels of bone regeneration and inflammation. The group treated with a blood clot showed more bone regeneration without inflammation at 15 days. However, after 30 days, complete closure of the defect with immature tissue was observed in this group, while limited new bone formation occurred in the other groups, accompanied by mild inflammation.CONCLUSIONS. Overall, the study suggests that calcium silicate-based sealers can induce new bone formation, but they do not offer superior bone repair compared to natural healing with a blood clot alone.

The present study assessed the physical and biological properties of membranes obtained by the electrospinning of a polymeric blend (70:30) of poly(lactic‐co‐glycolic acid) (PLGA) and poly(trimethylene carbonate) (PTMC) in two different thicknesses. Membranes were formed with or without incorporating ceramic particles containing 60% hydroxyapatite (HA) and 40% β‐tricalcium phosphate (TCP). The following parameters were assessed: (i) ultrastructural characterization, (ii) measurement of surface area and total pore volume, (iii) tear resistance, (iv) dissolution pH evaluation, (iv) in vivo assessment of potential new bone formation in critical defects. The specimens were divided into the following sample groups: G1 = 300 μm, G2 = 300 μm + HA/TCP, G3 = 600 μm, G4 = 600 μm + HA/TCP. The findings revealed fibrillar structure in various orientations in all the groups. Surface area, total pore volume, and dissolution pH were higher in G2 and G4, compared with G1 and G3. Tear resistance was higher for thicker membranes. Furthermore, G4 showed a greater percentage of new bone volume and density at 30 days than the other groups. The results suggest that the polymeric blend of PLGA and PTMC is a promising material for use as a membrane for clinical guided bone regeneration procedures, and represents a potential alternative to the currently available products.

Statins, such as simvastatin, are commonly used to treat hyperlipidemia and prevent cardiovascular diseases. However, simvastatin may suppress osteoclastogenesis, potentially reducing dental movement during orthodontic treatment. To mitigate this effect, low-level laser irradiation can be used for its photobiomodulatory properties. This study aims to assess the impact of combining simvastatin with photobiomodulation therapy on the regulation of bone metabolism. In this study, 56 male Wistar rats were divided into four groups: G1 – no orthodontic movement or simvastatin (n = 8); G2 – orthodontic movement with simvastatin 2.5 mg/kg (n = 16); G3 – orthodontic movement with saline solution and low-level laser 808 nm 1 J/point (n = 16); and G4 – orthodontic movement with simvastatin and low-level laser 808 nm 1 J/point (n = 16). Simvastatin was administered for 14 days, and dental movement was initiated with mini implants for the length of 7 or 14 days. Photobiomodulation occurred every 48 h during the experiment. The animals were euthanized after 14 and 21 days for clinical, histological, and micro-computed tomography analysis, as well as matrix metalloproteinase 2 (MMP2) and TIMP metallopeptidase inhibitor 1 (TIMP1) quantification. Statistical analysis was conducted using R software with a 5% significance level. Group G2 showed significantly less dental movement than G3 and G4 (p < 0.05). The BV/TV ratio was higher in G4 compared to G1 and G2. MMP2 levels were higher in G4 than G1 and G2 after 14 days, and in G3 compared to G2. After 21 days, MMP2 was higher in G2 and G3 than G1 and G4, and lower in G1 than G4 (p < 0.05). The results suggest that simvastatin reduces dental movement compared to laser-treated groups.

Objective This study focused on evaluating the effect of simvastatin on Runx-2, Osterix, interleukins 17, 22 and 23 gene expression in ligature-induced periodontitis in an animal model. Methods Wistar rats (n=20) were randomly assigned to two groups: the simvastatin test group (STG, n=10, daily oral administration of 25 mg/kg simvastatin), and the vehicle control group (VCG, n=10, vehicle,10 ml/kg of saline solution, orally). Periodontitis was induced by ligation around the lower molar (STG and VCG). The non-ligature contralateral molars were used as controls (n=10 from each group). After 14 days, the animals were euthanized, and the bone and gingival tissues surrounding the first lower molar were collected. Runx-2, Osterix in bone tissue, and IL-17, IL-22 and IL-23 in the gingival tissue, were evaluated by real-time polymerase chain reaction. The data were analyzed by Mann-Whitney test (α=5%). Results The Runx-2 expression was similar between the STG and VCG groups (p>0.05), whereas the Osterix expression. was higher for STG (p<0.05). The presence of simvastatin reduced the expression. of IL-17, IL-22 and IL-23 in STG compared with the levels identified in VCG for the same cytokines (p=0.029). Conclusion Simvastatin positively modulates Osterix gene expression and reduces the levels of mRNA of proinflammatory interleukins, which may contribute to avoid bone loss and inflammation promoted by periodontal disease.

The present in vitro study evaluated the effect of titanium dioxide nanotubes (nTiO₂) incorporated into glass ionomer cement (GIC) on the growth and viability of Lactobacillus acidophilus (L. acidophilus). GIC (Ketac Molar EasyMix^® = KM) was added to concentrations of 0%, 3%, 5%, 7% by weight of nTiO₂ (20 nm in size). L. acidophilus strains (1x10⁸ CFU/mL) were cultivated on GIC discs with or without the addition of nTiO₂ for 1, 3 and 7 days, and the following parameters were evaluated: inhibition zone (mm) (n = 6); cell viability (Live/Dead) (n = 6); cell morphology (SEM) (15 KV, 2000X, n = 3). The data were submitted to ANOVA and the Tukey and Dunnett tests (α = 0.05). Regarding the agar diffusion test, there was no difference between GIC and the groups containing nTiO₂ (p > 0.05). As for bacterial viability, the percentage of viable bacteria was lower for GIC+7% nTiO₂ (p ≤ 0.05). There was no difference in the percentage of non-viable bacteria (p > 0.05). In addition, the morphology of L. acidophilus did not change in the presence of nTiO₂. It can be concluded that the incorporation of titanium dioxide nanotubes into GIC, particularly at 5%, reduced L. acidophilus viability, and might hence interfere negatively with the initial colonization process of the bacterial biofilm.