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Background and Objective: Osteoporosis is associated with bone microarchitecture alterations, and the depletion of estrogen during menopause is a major contributing factor to its development. The literature highlights the noteworthy role of gut microbiota in bone metabolism, particularly in the progression of osteoporosis. Periodontal disease leads to alveolar bone loss, which may be influenced by estrogen deficiency, and this mechanism is intricately associated with an imbalance in systemic microbiota. The aim of this study was to evaluate the effects of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019) and Lacticaseibacillus casei 01 (L. casei 01) administrations on an osteoporosis animal model. Materials and Methods: Thirty‐three female rats were randomly divided into three groups: control (C‐OVX), C‐OVX‐HN019 and C‐OVX‐LC01. All animals were ovariectomized. In groups C‐OVX‐HN019 and C‐OVX‐LC01, the probiotics were administered for 4 months. All animals were euthanized after 16 weeks from ovariectomy. Microtomographic, histopathological and immunohistochemical examinations were conducted on periodontal tissues, whereas histomorphometry, histopathological and immunohistochemical analyses were carried out on the intestine. The levels of estradiol were assessed in blood using an immunoenzymatic assay. The data were subjected to statistical analyses (p <.05). Results: The C‐OVX‐LC01 group exhibited a significant reduction in alveolar bone porosity and an increase in connective tissue density compared to C‐OVX (p <.05). The C‐OVX‐HN019 and C‐OVX‐LC01 groups presented reduced expression of TRAP and RANKL compared to the C‐OVX (p <.05). The C‐OVX group presented villi defects, mild neutrophil infiltration, decrease in both villous height and intestinal crypts and reduced expression of intestinal junctional epithelium markers e‐cadherin and claudin 01 compared to C‐OVX‐HN019 and C‐OVX‐LC01 (p <.05). The C‐OVX group had lower estradiol levels than C‐OVX‐HN019 and C‐OVX‐LC01 (p <.05). Conclusion: The probiotic therapy promoted a reduction in alveolar bone destruction and intestinal permeability as well as an increase in estradiol levels in ovariectomized rats. Specifically, the probiotic strain Lacticaseibacillus casei 01 exhibited greater effectiveness compared to Bifidobacterium animalis subsp. lactis HN019, indicating strain‐dependent outcomes. [ABSTRACT FROM AUTHOR]

Objective: The study delved into the epigenetic factors associated with periodontal disease in two lineages of mice, namely C57bl/6 and Balb/c. Its primary objective was to elucidate alterations in the methylome of mice with distinct genetic backgrounds following systemic microbial challenge, employing high-throughput DNA methylation analysis as the investigative tool., Methods: Porphyromonas gingivalis ( Pg )was orally administered to induce periodontitis in both Balb/c and C57bl/6 lineage. After euthanasia, genomic DNA from both maxilla and blood were subjected to bisulfite conversion, PCR amplification and genome-wide DNA methylation analysis using the Ovation RRBS Methyl-Seq System coupled with the Illumina Infinium Mouse Methylation BeadChip., Results: Of particular significance was the distinct methylation profile observed within the Pg -induced group of the Balb/c lineage, contrasting with both the control and Pg -induced groups of the C57bl/6 lineage. Utilizing rigorous filtering criteria, we successfully identified a substantial number of differentially methylated regions (DMRs) across various tissues and comparison groups, shedding light on the prevailing hypermethylation in non-induced cohorts and hypomethylation in induced groups. The comparison between blood and maxilla samples underscored the unique methylation patterns specific to the jaw tissue. Our comprehensive methylome analysis further unveiled statistically significant disparities, particularly within promoter regions, in several comparison groups., Conclusion: The differential DNA methylation patterns observed between C57bl/6 and Balb/c mouse lines suggest that epigenetic factors contribute to the variations in disease susceptibility. The identified differentially methylated regions associated with immune regulation and inflammatory response provide potential targets for further investigation. These findings emphasize the importance of considering epigenetic mechanisms in the development and progression of periodontitis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hernandez Martinez, Glessner, Finoti, Silva, Messora, Coletta, Hakonarson and Palioto.)

Objectives: Periodontal disease is understood to be a result of dysbiotic interactions between the host and the biofilm, causing a unique reaction for each individual, which in turn characterizes their susceptibility. The objective of this study was to chronologically evaluate periodontal tissue destruction induced by systemic bacterial challenge in known susceptible (BALB/c) and resistant (C57BL/6) mouse lineages., Material and Methods: Animals, 6-8 weeks old, were allocated into three experimental groups: Negative control (C), Gavage with sterile carboxymethyl cellulose 2%-without bacteria (Sham), and Gavage with carboxymethyl cellulose 2% + Porphyromonas gingivalis (Pg-W83). Before infection, all animals received antibiotic treatment (sulfamethoxazole/trimethoprim, 400/80 mg/5 mL) for 7 days, followed by 3 days of rest. Microbial challenge was performed 3 times per week for 1, 2, or 3 weeks. After that, the animals were kept until the completion of 42 days of experiments, when they were euthanized. The alveolar bone microarchitecture was assessed by computed microtomography., Results: Both C57BL/6 and BALB/c mice exhibited significant bone volume loss and lower trabecular thickness as well as greater bone porosity compared to the (C) and (Sham) groups after 1 week of microbial challenge (p < .001). When comparing only the gavage groups regarding disease implantation, time and lineage, it was possible to observe that within 1 week of induction the disease was more established in BALB/c than in C57BL/6 (p < .05)., Conclusions: Our results reflected that after 1 week of microbial challenge, there was evidence of alveolar bone loss for both lineages, with the loss observed in BALB/c mice being more pronounced., (© 2023 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

Background: This study evaluated the effects of the probiotic Bifidobacterium animalis subsp. lactis HN019 (HN019) in the development of experimental periodontitis (EP) in rats submitted to chemotherapy (5-fluorouracil [5FU])., Methods: Eighty male rats were divided into the following groups: control (C); treated with 5FU (60 mg/kg at day 30 and 40 mg/kg at day 32); treated with probiotic (HN019) (daily, for 44 days, starting at day 0); treatment with 5FU and probiotic (5FU-HN019); only EP (EP) (ligature placed on lower first molars at day 30, maintained for 14 days); EP and treatment with 5FU (EP-5FU); EP and treatment with probiotic (EP-HN019); and EP and treatment with 5FU and probiotic (EP-5FU-HN019). Euthanasia occurred at day 44. Morphometric, histomorphometric, microtomographic, immunohistochemical, immunoenzymatic, and gene expressions analyses were performed. The data obtained were statistically analyzed (p < 0.05)., Results: The EP-5FU-HN019 group showed less bone and connective tissue loss when compared with EP-5FU group, while EP-HN019 and EP-5FU-HN019 groups had greater bone volume than EP and EP-5FU groups, respectively (p < 0.05). A decrease in immunostaining for tartrate-resistant acid phosphatase and RANKL, an increase for osteoprotegerin and lower interleukin-1β levels were observed in EP-5FU-HN019 group, when compared with EP-5FU group (p < 0.0001). Probiotic therapy led to an increase in the proportions of B. lactis in the feces (p = 0.0018), but not in the biofilm, and reduced the expression of Fusobacterium nucleatum and Prevotella intermedia in the biofilm (p < 0.0001)., Conclusion: B. lactis HN019 reduced the severity of EP in rats submitted to chemotherapy, modulating immunoinflammatory parameters in periodontal tissues and reducing periodontopathogens expression on biofilm in rats submitted to chemotherapy., (© 2022 American Academy of Periodontology.)

The aim of this study was to evaluate the use of a new porcine bone graft in rat calvaria bone defects. Critical defects were surgically created in 24 rats that were divided into four experimental groups according to defect filling (n = 6): Control Group (CG)—blood clot; Porcine Bone Group (PG)—porcine-derived bone substitute; (BG): Bio-Oss Group (BG)−chemically and heat-treated bovine graft; Bonefill Group (BFG)—chemically treated bovine bone substitute. Euthanasia of the animals occurred 30 days after the surgery, and the area of the original surgical defect and the surrounding tissues were removed for micro-CT and histomorphometric analysis. In the micro-CT evaluation, the PG presented statistically significant differences (p < 0.05) in comparison to the CG, BG and BFG, for the parameters percentage of Bone Volume (BV/TV), Surface Bone Density (BS/TV), Number of Trabeculae (Tb.N) and Bone Connectivity (Conn), but not for Total Porosity (Po.tot) and Trabecular Thickness (Tb.Th). The histomorphometric analysis showed that the PG presented similar results to the BG regarding newly formed bone extension and to the BG and BFG regarding newly formed bone area. The porcine-derived graft presented superior microtomographic and histomorphometric results when compared to the two bovine bone substitutes.

Objective: This study evaluated the effect of non-surgical periodontal therapy (NSPT) on the cytokine profile in gingival crevicular fluid (GCF) in patients with breast cancer and periodontitis., Methods: Forty patients were allocated into the periodontitis group (P) (n = 20) and breast cancer with periodontitis group (BC/P) (n = 20). Two days before the removal of infectious foci from the oral cavity and NSPT, as well as periodontal reevaluations, C-reactive protein, neutrophils (10 3 μL), and platelets (10 3 μL), were evaluated. The following cytokines in GCF, interleukin (IL)-4, IL-10, IL-2, IL-6, IL-1β, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and transforming growth factor-β (TGF-β) were evaluated by the Luminex assay at baseline, and 45 and 180 days after therapy. Cytokine levels were analyzed for correlations with the clinical parameters: clinical attachment level (CAL), probing depth (PD), bleeding on probing (BOP), and plaque index (PI)., Results: After NSPT, IL-2, TNF-α, and TGF-β were downregulated (p<0.05) in the BC/P. In the P group, INF-γ, IL-2, and TNF-α were downregulated (p<0.05), and TGF-β was increased (p<0.05). At 180 days, IL-6 in GCF was significantly positively correlated with PD and CAL (r=0.45, r=0.56) in the BC/P (p<0.05). In the P group, IL-1β in GCF was positively correlated with PD and CAL (r=0.56, r=0.59) at 45 days (p<0.05)., Conclusion: NSPT, before the start of chemotherapy, helps to reduce the inflammatory markers associated with the activity of periodontal disease, favoring a less inflammatory pattern, to avoid the exacerbation of periodontitis., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Periodontal pathogenesis takes into consideration that disease results from a complex inflammatory immune response. Among the major cytokines related to periodontal damage, interleukin (IL)-6 enhances a cascade of tissue destruction. Tocilizumab (TCZ) is a humanized monoclonal anti-human IL-6 receptor that inhibits IL-6-mediated proinflammatory activity. This study aimed to elucidate whether TCZ inhibits the deleterious effect of ligature-induced periodontitis., Methods: Experimental ligature-induced periodontitis was treated with systemic administration of TCZ intraperitoneally in three different concentration dosages (2 mg/kg, 4 mg/kg, and 8 mg/kg. Euthanasia occurred at 7 and 14 days after the initiation of the study. Local changes in the alveolar bone were measured by bone volume, the ratio of bone volume, and trabecular thickness using microcomputed tomography. Attachment loss and inflammatory infiltrate were evaluated by histology. Immune response was analyzed focusing on the Th17 pattern., Results: TCZ inhibited alveolar bone resorption and attachment loss in 7 and 14 days for all dosage groups in comparison to controls (P  < 0.05). Besides, TCZ induced lower expression of inflammatory infiltrate (P <0.05) and less production of Th17-related cytokines (P <0.05) and RANKL (P <0.05)., Conclusions: The inhibition of IL-6-mediated proinflammatory activity by IL-6R blocking reduced alveolar bone resorption and attachment loss supported by the modulation of the Th17 periodontal response. Considering the inflammatory status, modulatory therapy may be a promising approach to periodontal disease., (© 2021 American Academy of Periodontology.)

The purpose of this study was to evaluate the effects of systemic administration of the probiotic Bifidobacterium animalis subsp. lactis HN019 (HN019) on ligature-induced periodontitis in rats with experimental rheumatoid arthritis (RA). 28 rats were divided into four groups (n=7): RA (rheumatoid arthritis), RA/PROB (probiotic), RA/EP (experimental periodontitis) and RA/EP/PROB. From day zero, HN019 was added daily to the water of the PROB groups animals until the end of the experiment. From day seven, RA was induced. On day 28, in EP groups, ligatures were positioned around mandibular first molars and remained in position for 11 days, in order to induce periodontitis. The animals were euthanised on day 39. Microtomographic, histomorphometric, immunoenzymatic and microbiological analyses were performed. Data were statistically analysed ( P <0.05). Group RA/EP/PROB presented reduced alveolar bone loss, tumour necrosis factor-α and interleukin (IL)-6 levels and increased IL-17 levels when compared with group RA/EP. There were no significant differences regarding connective tissue attachment level and IL-10 levels between groups RA/EP and RA/EP/PROB. Group RA/PROB showed decreased anti-citrullinated protein antibodies levels when compared with groups RA and RA/EP. Group RA/EP/PROB presented a higher rate of aerobic/anaerobic bacteria than group RA/EP. Systemic administration of HN019 promoted a protective effect against periodontal tissue destruction, decreasing both bone loss and inflammatory mediators and increasing the proportion of bacteria compatible with periodontal health, in rats with experimental RA and EP.

This study determined the effect of curcumin on bone healing in animals with diabetes mellitus (DM). One hundred rats were divided into five groups: DM+PLAC, DM+CURC, DM+INS, DM+CURC+INS, and non-DM (CURC, curcumin; PLAC, placebo; INS, insulin). Critical calvarial defects were created and titanium implants were inserted into the tibiae. Calvarial defects were analyzed histometrically, and BMP-2, OPN, OPG, RANKL, Runx2, Osx, β-catenin, Lrp-5, and Dkk1 mRNA levels were quantified by PCR. The implants were removed for a torque evaluation, the peri-implant tissue was collected for mRNA quantification of the same bone-related markers, and the tibiae were submitted to micro-computed tomography. The DM+CURC+INS and non-DM groups exhibited greater closure of the calvaria when compared to the DM+PLAC group (P<0.05). Increased retention of implants was observed in the DM+CURC, DM+CURC+INS, and non-DM groups when compared to the DM+PLAC group (P<0.05). CURC improved bone volume and increased bone-implant contact when compared to DM+PLAC (P<0.05). In calvarial samples, CURC favourably modulated RANKL/OPG and Dkk1 and improved β-catenin levels when compared to DM+PLAC (P<0.05). In peri-implant samples, Dkk1 and RANKL/OPG were down-regulated and BMP-2 up-regulated by CURC when compared to DM+PLAC (P<0.05). CURC reverses the harmful effects of DM in bone healing, contributing to the modulation of bone-related markers., (Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Purpose: This study histomorphometrically analyzed the effect of autogenous platelet-rich plasma (PRP) on healing of fresh frozen bone allograft (FFBA) in bony defects in rat calvaria., Materials and Methods: A 5mm-diameter defect was created in the calvarium of 30 rats. Animals were divided into three groups: C (defect was filled by blood clot only), FFBA (defect was filled with 0.01mL of FFBA), and FFBA/PRP (defect was filled with 0.01mL of FFBA combined with 100µL of PRP). All animals were euthanized at 30 days postoperatively. Histomorphometry and histology analyses were performed. Data were statistically analyzed (analysis of variance, Tukey, p<.05)., Results: FFBA had a statistically smaller new bone area than groups FFBA/PRP and C. No statistically significant differences were observed between groups FFBA and FFBA/PRP with regard to remaining bone graft particle area., Conclusion: It can be concluded that (1) PRP improved the incorporation of FFBA, increasing the amount of new bone formed; (2) PRP has not influenced the resorption of nonviable particles of the FFBA; and (3) presence of remaining FFBA particles might have accounted for the smaller amount of new bone observed in group FFBA when compared with control group., (© 2011 Wiley Periodicals, Inc.)

The purpose of this study was to analyze histomorphometrically the influence of the ratio of particulate autogenous bone (AB) graft/platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in rat calvaria. Fifty rats were divided into five groups: Group C (control), Group AB, Group AB/PRP-50, Group AB/PRP-100, and Group AB/PRP-150. A 5-mm diameter critical-size defect was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group AB, the defect was filled with 0.01 mL of AB graft. In Groups AB/PRP-50, AB/PRP-100, and AB/PRP-150, the defects were filled with 0.01 mL of AB graft combined with 50, 100, and 150 microL of PRP, respectively. All animals were euthanized at 30 days postoperative. Histomorphometry, using image analysis software, and histology analyses were performed. New Bone Area (NBA) and the remaining bone graft particles area (RPA) were calculated as a percentage of the total area of the original defect. Percentage data were transformed into arccosine for analysis. No defect completely regenerated with bone. Group AB/PRP-50 (41.78 +/- 13.48%) had a significantly greater NBA than Groups C (19.29 +/- 5.11%), AB (27.43 +/- 10.90%) or AB/PRP-150 (19.17 +/- 8.45%) (p < 0.05). No significant differences were observed between groups AB/PRP-50 and AB/PRP-100 or among groups AB, AB/PRP-100, and AB/PRP-150 with regard to NBA (p > 0.05). Group AB/PRP-150 (31.59 +/- 3.22%) had a significantly greater RPA than Groups AB (19.09 +/- 5.21%), AB/PRP-50 (17.33 +/- 4.43%), and AB/PRP-100 (19.72 +/- 3.62%) (p < 0.001). No significant differences were observed among groups AB, AB/PRP-50, and AB/PRP-100 with regard to RPA (p > 0.05). The ratio AB graft/PRP influences bone healing in surgically created CSD in rat calvaria.

Objective: The objective of this study was to histologically analyze the influence of the platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in the calvaria of diabetic rats., Study Design: A total of 20 diabetic rats were divided into 2 groups: C (control) and PRP. A 5-mm diameter CSD was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group PRP, 0.35 mL of PRP was placed in the defects. All animals were humanely killed 30 days postoperatively. Histometric and histologic analyses were performed. Data were statistically analyzed (t test, P < .05)., Results: No defect completely regenerated with bone. Group PRP had a statistically greater amount of bone formation than Group C (37.22% +/- 6.00% and 21.68% +/- 11.35%, respectively)., Conclusion: PRP placed in the defects significantly enhanced bone healing in CSD in the calvaria of diabetic rats both qualitatively and quantitatively., (Copyright 2010 Mosby, Inc. All rights reserved.)

This immunohistochemical analysis evaluated the influence of the proportion of particulate autogenous bone (AB) graft/platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in rat calvaria. 25 rats were divided into 5 groups: C (control), AB, AB/PRP-50, AB/PRP-100 and AB/PRP-150. A 5 mm diameter critical-size defect was created in the calvarium of each animal. In Group C, defect was filled by blood clot only. In Group AB, defect was filled with AB graft. In Groups AB/PRP-50, AB/PRP-100 and AB/PRP-150, defects were filled with AB graft combined with 50, 100 and 150 microl of PRP, respectively. Animals were euthanized at 30 days post-operative. Osteocalcin (OC) and osteopontin (OP) immunohistochemical staining were performed. OP-positive and OC-positive cells were quantified. The amount of vital bone (VBA) and remaining bone graft particles (RPA) were calculated as percentage of the total area of the original defect. Data were statistically analyzed (ANOVA, Tukey, p<0.05). Group AB/PRP-100 presented a significantly higher number of OP-positive cells than groups C, AB/PRP-50 and AB/PRP-150 (p<0.05) and also a significantly higher number of OC-positive cells than all of the other groups (p<0.05). The number of OP-positive cells in Group AB/PRP-150 was significantly lower than in Group AB (p<0.05). Statistically significant differences were not found between groups with regard to either VBA or RPA (p>0.05). However, clear trends were indicated by an increase in VBA in Group AB/PRP-100 when compared to groups C, AB and AB/PRP-150 and an increase in RPA in Group AB/PRP-150 when compared to groups AB, AB/PRP-50 and AB/PRP-100. The proportion AB graft/PRP seems to influence bone healing in CSD in rat calvaria. The highest expression of osteocalcin and osteopontin, and thus the most developed healing, was found in Group AB/PRP-100 indicating that there may be an optimal proportion beyond which increasing the concentration PRP is deleterious.