Effects of platelet-rich fibrin produced by three centrifugation protocols on bone neoformation in defects created in rat calvaria.

This study evaluated the potential of Leukocyte-platelet-rich fibrin (L-PRF; fixed angle centrifugation protocol), Advanced-platelet-rich fibrin (A-PRF; low-speed fixed angle centrifugation protocol), and Horizontal-platelet-rich fibrin (H-PRF; horizontal centrifugation protocol) in bone neoformation in critical size defects (CSDs) in rat calvaria. Thirty-two rats were divided into groups: Control (C), L-PRF, A-PRF, and H-PRF. 5 mm diameter CSDs were created in the animals' calvaria. Defects from group Control (C) were filled with blood clots, while defects from groups L-PRF, A-PRF, and H-PRF were filled with respective platelet-rich fibrin (PRF) membranes. L-PRF, A-PRF, and H-PRF were prepared from animal blood collection and specific centrifugation protocols. At 14 and 30 days, calcein (CA) and alizarin (AL) injections were performed, respectively. Animals were euthanized at 35 days. Microtomographic, laser confocal microscopy, and histomorphometric analyzes were performed. Data were statistically analyzed (ANOVA, Tukey, p < .05). L-PRF, A-PRF, and H-PRF groups showed higher values of bone volume (BV), newly formed bone area (NFBA), and precipitation of CA and AL than the C group (p < .05). The H-PRF group showed higher values of BV, number of trabeculae (Tb. N), NFBA, and higher precipitation of AL than the A-PRF and L-PRF groups (p < .05). Therefore, it can be concluded that: i) L-PRF, A-PRF, and H-PRF potentiate bone neoformation in CSDs in rat calvaria; ii) H-PRF demonstrated more biological potential for bone healing.

After tooth loss, the alveolar bone (which supports the teeth) undergoes a natural process called bone remodeling, which can lead to significant decreases in bone height and thickness over time. Faced with the need to replace missing teeth, especially when it comes to dental implants, the lack of supporting tissues can compromise their correct positioning, leading to negative impacts on the success and longevity of the treatment. Therefore, over the years, several materials and procedures have been proposed to preserve and regenerate oral tissues. Leukocyte-platelet-rich fibrin (L-PRF) consists of a membrane obtained by centrifuging the patient's blood in a fixed-angle centrifuge, allowing cells to be available to stimulate tissue regeneration directly at the place of action. Several reports demonstrate high potential in stimulating the formation of new tissues using L-PRF. In recent years, new protocols have been proposed to increase cell concentration and improve the regenerative potential of these membranes, changing the speed and time of centrifugation and introducing horizontal centrifugation. However, there still needs to be concrete evidence of the superiority of the new protocols in relation to the original protocol. In this study, we evaluated the healing of defects created in rat calvaria using platelet aggregates obtained through different centrifugation protocols. Within the limits of this study, it can be concluded that platelet aggregates improve bone healing, and horizontal centrifugation promotes more satisfactory results compared to fixed-angle protocols.

Effects of oral administration of Bifidobacterium animalis subsp. lactis HN019 on the treatment of plaque-induced generalized gingivitis.

OBJECTIVES: This double-blind, randomized, placebo-controlled clinical trial evaluated the adjuvant effects of Bifidobacterium lactis HN019 on the treatment of plaque-induced generalized gingivitis. MATERIALS AND METHODS: Sixty patients were submitted to professional supragingival scaling and prophylaxis. They were randomly assigned to test (probiotic lozenges containing B. lactis HN019, n = 30) or control (placebo lozenges, n = 30) groups. Lozenges were consumed twice a day for 8 weeks. Bleeding on probing (BoP), Gingival Index (GI), Plaque Index (PI), probing depth (PD), and clinical attachment level (CAL) were evaluated at baseline and after 2 and 8 weeks. Gingival crevicular fluid (GCF) was collected at baseline and at 8 weeks for analysis of the inflammatory mediators IL-1ß, IL-1α, IL-8, MCP-1, and MIP-1ß. Data were statistically analyzed (p < 0.05). RESULTS: After 8 weeks, both groups showed reduction in the percentage of PI, with no significant difference between groups (p = 0.7423). The test group presented a lower percentage of BoP and a higher percentage of sites with GI ≤ 1 when compared with the control group at the end of the study (p < 0.0001). At 8 weeks, the test group had a greater number of patients without generalized gingivitis than the control group (20 and 11 patients, respectively; p < 0.05). The test group presented significantly lower levels of IL-1α, IL-1ß, and MCP-1 in GCF than the control group at the end of the study (p < 0.05). CONCLUSION: The adjunct use of B. lactis HN019 promotes additional clinical and immunological benefits in the treatment of generalized gingivitis. CLINICAL RELEVANCE: B. lactis HN019 can be an efficient and side-effect-free adjunct strategy in the treatment of generalized gingivitis.

The Interplay of Raloxifene and Sonochemical Bio-Oss in Early Maxillary Sinus Bone Regeneration: A Histological and Immunohistochemical Analysis in Rabbits.

The study aimed to assess the efficacy of using Raloxifene with ultrasonic processing to enhance Bio-Oss®, a bone graft substitute, for maxillary sinus bone height reconstruction. A total of 24 rabbit maxillary sinuses were distributed into three groups, each receiving different treatments: Bio-Oss® only, sonicated Bio-Oss, and sonicated Bio-Oss® with Raloxifene. Surgical procedures and subsequent histomorphometric and immunohistochemistry analyses were conducted to evaluate the bone formation, connective tissue, and remaining biomaterial, as well as the osteoblastic differentiation and maturation of collagen fibers. Results indicated that the sonicated Bio-Oss® and Bio-Oss® groups showed similar histological behavior and bone formation, but the Raloxifene group displayed inflammatory infiltrate, low bone formation, and disorganized connective tissue. The statistical analysis confirmed significant differences between the groups in terms of bone formation, connective tissue, and remaining biomaterial. In conclusion, the study found that while sonicated Bio-Oss® performed comparably to Bio-Oss® alone, the addition of Raloxifene led to an unexpected delay in bone repair. The findings stress the importance of histological evaluation for accurate bone repair assessment and the necessity for further investigation into the local application of Raloxifene. Future research may focus on optimizing bone substitutes with growth factors to improve bone repair.

Is it possible to decrease the occurrence of dental implant failures through the use of preventative antibiotics?

DESIGN: The research was a randomized placebo-controlled clinical trial evaluating the use of clindamycin as a preoperative medication to prevent the dental implant. AIM: The purpose of the study was to assess if giving a single dose of 600 mg oral clindamycin 1 h before a conventional dental implant procedure could reduce the risk of early implant failure and post-surgical complications in healthy adults. METHODS: A clinical trial was conducted with ethical standards, utilizing a randomized, double-blind, placebo-controlled approach. Healthy adults who required a single oral implant and had no previous surgical site infection or need for bone grafting were enrolled. Before surgery, participants were given either oral clindamycin or placebo at random. A single surgeon performed all operations, and patients were observed by a trained professional on multiple postoperative days. The study considered early dental implant failure as the loss or removal of an implant. Clinical, radiological, and surgical data were analyzed statistically to identify group differences. The number of subjects needed to treat, or harm, was calculated. RESULTS: The research involved two groups of 31 patients each: the control group and the clindamycin group. Two patients in the clindamycin group experienced implant failures (NNH = 15, p = 0.246). Three patients in the study had postoperative infections; two of them were from the placebo group, while one from the clindamycin group had an unsuccessful treatment outcome. The relative risk was 0.5, with a CI of 0.05-5.23 and an absolute risk reduction of 0.03. The confidence interval was -0.07-0.13, and the NNT was 31, with a CI of 7.2-∞ and p = 0.5. In addition, only one patient treated with clindamycin reported gastrointestinal disturbances and diarrhea. CONCLUSIONS: There is no conclusive evidence to suggest that administering clindamycin prior to oral implant surgery in healthy adults reduces the risk of implant failure or post-surgical complications.

Comparison of the effects of platelet concentrates produced by high and low-speed centrifugation protocols on the healing of critical-size defects in rat calvaria: a microtomographic and histomorphometric study.

The current study evaluated the healing of critical-size defects (CSD) created in rat calvaria treated with platelet concentrates produced by high-speed (Leukocyte- and Platelet-Rich Fibrin - L-PRF) and low-speed (Advanced Platelet-Rich Fibrin - A-PRF) protocols of centrifugation. Twenty-four rats were distributed into three groups: Control, L-PRF, and A-PRF. Five mm diameter CSD were created on the animals' calvaria. The defects of the L-PRF and A-PRF groups were filled with 0.01 ml of L-PRF and A-PRF, respectively. The control group defects were filled with a blood clot only. All animals were euthanized on the 35th postoperative day. Histomorphometric and microtomographic analyses were then performed. The L-PRF and A-PRF groups had significantly higher bone volume and neoformed bone area than those of the control group and lowered bone porosity values (p < .05). No significant differences were observed between A-PRF and L-PRF groups for the analyzed parameters. Therefore, it can be concluded that i) L-PRF and A-PRF potentiated the healing of CSD in rat calvaria; ii) high and low-speed centrifugation protocols did not produce PRF matrices with different biological impacts on the amount of bone neoformation.

Probiotics During the Therapeutic Management of Periodontitis.

Scaling and root planing is the gold standard for the treatment of periodontitis, but administration of systemic antibiotics may be needed especially for sites with deep probing depths, or in the presence of comorbidities. However, treated sites are subject to recolonization with a microbiota similar to that present before therapy, and supportive periodontal therapy is employed after the treatment of active disease. The use of beneficial organisms, known as probiotics, seems an attractive proposal to promote a healthy associated subgingival microbiome and to control inflammation for the management of periodontitis. The mechanisms underlying the benefits promoted by probiotics involve interference on periodontopathogens, modulation of the exacerbated immune host response and the ability to restore the integrity of the epithelial barrier on mucosa surfaces. This review examines the scientific data related to the effects of probiotics on the treatment of periodontal diseases and addresses the future approaches necessary for their implementation.

A new mixed model of periodontitis-induced preeclampsia: A pilot study.

OBJECTIVES/BACKGROUND: Recent studies have shown that periodontal disease is strongly related to gestational complications such as preeclampsia (PE). PE is responsible for 42% of maternal deaths worldwide and kills approximately 76 000 women a year. In addition, children born under PE conditions are at increased risk of hospitalization due to metabolic disorders, epilepsy, and other complications. Numerous reviews and clinical studies on PE have been published, but the mechanisms underlying the relationship between periodontal disease and PE and the way periodontopathogens alter vascular response in pregnant women remain unclear. METHODS: This study aims to verify whether periodontal disease induces PE by using the association of two periodontitis (PD) models: ligature and oral Porphyromonas gingivalis (P. gingivalis) W83 inoculation in Wistar rats. At gestational day 5, the ligature was placed on each mandibular first molar, which was followed by daily oral P. gingivalis inoculation for 15 days. At gestational day 19, urine was collected, and invasive arterial pressure was measured. The animals were euthanized, and plasma and tissues were collected. RESULTS: After 15 days of the association of ligature and P. gingivalis inoculation, the animals presented the characteristic symptoms of PE: altered blood pressure, proteinuria, and change in litter size (number of pups) and pup weight when compared to the control group (p < .005). The PE animals also presented greater bone porosity, trabecular separation, and reduced bone volume in the hemimandibles, as well as altered inflammatory response. The level of cytokine IL-6 was higher in the PE group than in the control group (p < .005). CONCLUSION: The association of two PD models effectively induced PE. To our knowledge, this is the first study on the oral use of P. gingivalis for PE induction. Our results support the importance of PD as a possible cause for PE development, opening an important new avenue to study cause and consequence relationships in inflammation and PE due to exposure to periodontal infection.

Root coverage using coronally advanced flap with porcine-derived acellular dermal matrix or subepithelial connective tissue graft: a randomized controlled clinical trial.

OBJECTIVE: The aim of this study is to investigate the use of a porcine-derived acellular dermal matrix (MD) in root coverage procedures combined with extended coronally positioned flap (eCAF), in comparison to the subepithelial connective tissue graft (SCTG) associated with the eCAF. MATERIAL AND METHODS: Eighteen adult patients presenting bilateral type 1 gingival recession were randomly assigned to SCTG or MD groups. Clinical and patient-based outcomes were recorded at 3 and 6 months after the surgical procedure. RESULTS: Both groups showed a significant reduction in the mean recession height of 3.33 ± 0.89 mm to 1.24 ± 1.10 mm (MD) and 3.21 ± 0.8 mm to 0.83 ± 0.86 mm (SCTG) without difference between groups. Six patients in the test group and eight in the control group obtained complete root coverage. The keratinized tissue height and thickness (KTT) showed a significant increase after 3 and 6 months in both groups. The average KTT gains were 0.39 ± 0.4 mm (MD) and 0.51 ± 0.5 mm (SCTG) (p < 0.05). Performing multivariate analysis suggests that MD addition to coronally advanced flaps may be similar to SCTG. CONCLUSION: The MD had similar results in comparison to SCTG and in the context of reducing patient morbidity it can be used as an alternative for the treatment of gingival recessions. CLINICAL RELEVANCE: The SCTG is the gold standard therapy for root coverage. The MD has been widely used in mucogingival surgery as a substitute for SCTG and proposed similar results. A substitute is very important for clinicians and patients. It will give a better postoperative and possibilities to treat multiples recession. (Clinicaltrials.gov Identifier: NCT03675334).

Root coverage of gingival recessions with non-carious cervical lesions: a controlled clinical trial.

OBJECTIVE: The non-carious cervical lesion (NCCL) is commonly produced by improper toothbrushing techniques, occlusion trauma, anatomic mal-positioned teeth, and acid erosion, thus sharing the same etiology of gingival recession (GR). The association of a graft to the coronally advanced flap had demonstrated the best long-term outcome for root coverage (RC). However, substitutes for the autogenous graft must be studied. This split-mouth clinical trial investigates the RC and the increase in keratinized tissue (KT) when comparing RC of NCCLs associated with GR with intact roots using an extended coronally advanced flap (ECAF) associated with the acellular dermal matrix graft (ADMG), a connective tissue replacement graft. MATERIAL AND METHODS: Seventeen individuals with bilateral GR were included in the study. One side had a NCCL (TG) and the opposite root was intact (CG). All patients were treated with the ECDF associated with ADMG. All clinical parameters were assessed at baseline and 6 months postoperative. RESULTS: Root coverage means (CG, 69.5 ± 19 and TG. 72.2 ± 16.5; p value = 0.849570) were not significantly different between control and test groups. In addition, the KT had an increase in the follow-up period for both groups. CONCLUSION: GR associated with NCCLs can be successfully treated with the ECDF and ADMG. CLINICAL RELEVANCE: Patients frequently search for GR treatment due to cervical wear, root sensitivity, and compromising aesthetics. The NCCL participates with the same issues. The present study contributes to the literature that GR associated with NCCLs can be successfully treated with the ECAF and the ADMG.

Effects of leukocyte- and platelet-rich fibrin associated or not with bovine bone graft on the healing of bone defects in rats with osteoporosis induced by ovariectomy.

OBJECTIVE: To evaluate the healing of critical size defects (CSDs) in calvaria of rats with osteoporosis induced by ovariectomy and treated with leukocyte- and platelet-rich fibrin (L-PRF) associated or not with bovine bone graft (XENO). MATERIAL AND METHODS: A total of 32 rats underwent a bilateral ovariectomy procedure. After 3 months, one 5 mm in diameter CSD was created in the middle of the calvaria of each animal. In group C, defect was filled with blood clot only. In PRF, XENO, and PRF-XENO groups, defects were filled with 0.1 ml of L-PRF, 0.1 ml of XENO, and a mixture of 0.1 ml of L-PRF plus 0.1 ml of XENO, respectively. L-PRF compressed clots were used to cover the defects in PRF and PRF-XENO groups. Animals were submitted to euthanasia at 30 postoperative days. Histomorphometric, microtomographic, and immunohistochemical analyses were performed. RESULTS: PRF-XENO group presented greater amount of neoformed bone (NB) when compared with XENO group, as well as higher expression of vascular endothelial growth factor (VEGF), osteocalcin (OCN), and bone morphogenetic protein (BMP-2/4) (p < .05). PRF group presented increased amount of NB and higher expression of VEGF, OCN, BMP-2/4, and Runt-related transcription factor 2 (RUNX-2) when compared with group C (p < .05). CONCLUSIONS: (a) The isolated use of L-PRF clot can improve bone neoformation in CSDs in rats with osteoporosis induced by ovariectomy, but seems to lead to decreased amount of bone neoformation when compared to the isolated use of XENO; (b) L-PRF potentiates the healing of XENO in rats with osteoporosis induced by ovariectomy.

Resveratrol reverses the negative effect of smoking on peri-implant repair in the tibia of rats.

OBJECTIVES: Innovative approaches capable to improve peri-implant bone repair are relevant in the presence of smoking, a risk factor for healing around implants. This study investigated the effect of resveratrol (RESV) on peri-implant repair, and its influence on bone-related markers in rats submitted to cigarette smoking inhalation (CSI). MATERIALS AND METHODS: One titanium implant was inserted in each tibiae of rats assigned to CSI+RESV (n:18); CSI+placebo (n:18); and non-CSI (n:18). One implant was removed for counter torque, and the peri-implant tissue was collected for mRNA quantification of BMP-2, OPN, Runx2, Lrp-5, Osx, ß-catenin, Dkk1, OPG, and RANKL. The other tibia was submitted to microCT to measure: bone volume, bone porosity, trabecular spacing, trabecular thickness, and bone-implant contact (BIC). RESULTS: No differences were detected between counter torque in CSI+RESV and non-CSI group (p > 0.05), whereas CSI+placebo group presented lower values when compared to the others (p < 0.05). RESV improved the BIC in CSI rats without differences when compared to non-CSI group (p > 0.05), whereas CSI+placebo showed reduced BIC when compared to the other groups (p < 0.05). RESV reduced RANKL/OPG and Lrp-5 levels and increased ß-catenin in CSI rats when compared to CSI+placebo (p < 0.05). CONCLUSION: Although further investigations should be considered using oral models of dental implants, within the limits of the present study, it was concluded that RESV reverses the negative effects of smoking in the peri-implant repair, benefiting the modulation of bone-related markers.

Antimicrobial photodynamic therapy as adjunct to non-surgical periodontal treatment in smokers: a randomized clinical trial.

OBJECTIVES: This study aims to investigate the additional influence of multiple applications of antimicrobial photodynamic therapy (aPDT) in smokers with chronic periodontitis. MATERIALS AND METHODS: Twenty smokers with chronic periodontitis were treated in a split-mouth design study with aPDT adjunct to Scaling and Root Planing (SRP) or SRP. aPDT was performed by using a laser light source with 660 nm wavelength associated with a photosensitizer. The applications were performed in four episodes (at days 0, 2, 7, and 14). All patients were monitored for 90 days. Plaque index, probing depth, clinical attachment level, and bleeding on probing were performed at baseline, 30, and 90 days after the SRP. Gingival crevicular fluid and subgingival plaque samples were collected for immunological and microbiological analysis, respectively. Data obtained were statistically analyzed. RESULTS: aPDT as an adjunct to SRP did not demonstrate statistically significant advantages on clinical parameters when compared with SRP alone. No statistic significant differences between groups were observed (p < 0.05). Levels of anti-inflammatory cytokines and bacterial species were comparable in both groups at day 90 after treatment. CONCLUSION: Periodontal treatment with SRP + aPDT in multiples episodes was not able to promote additional clinical, immunological, and microbiological benefits in smokers when compared SRP alone in patients with chronic periodontitis. CLINICAL RELEVANCE: Multiple episodes of aPDT adjunctive to non-surgical treatment did not improve significantly the clinical, immunological, and microbiological parameters when compared with SRP alone. More randomized clinical trials are needed to evaluate adjuvant therapies for scaling and root planning in smokers with chronic periodontitis. ClinicalTrials.gov Identifier: NCT03039244.

Adjunctive effect of antimicrobial photodynamic therapy in induced periodontal disease. Animal study with histomorphometrical, immunohistochemical, and cytokine evaluation.

Scaling and root planing (SRP) may not always be effective in preventing periodontal disease (PD) progression. The aim of this study was to evaluate the adjunctive effect of antimicrobial photodynamic therapy (aPDT) to SRP on induced PD in rats, analyzing histomorphometrical, immunohistochemical, and immunoenzymatic parameters. Ligatures were placed around the first mandibular molars and second maxillary molars of 60 rats to induce PD. After 14 days, they were removed and the animals were divided into six groups, with nine animals each: G1 = no treatment, G2 = SRP, G3 = light-emitting diode (LED), G4 = SRP + aPDT, G5 = aPDT, and G6 = erythrosine. The animals were euthanized after 3, 7, and 15 days. There were also two control groups (n = 3): without PD (WPD) induction and with maximum PD (PD+). In the histomorphometrical analysis of linear bone loss, G4 showed a statistically significant difference from the other experimental groups after 3 and 15 days. The tartrate-resistant acid phosphatase (TRAP)-positive cell counting was significantly lower in G4 when compared to G2 and PD+ after 3 days. Immunoenzymatic assay shows the values of the ratio (RANKL/OPG × 100). The lowest value is from the WPD group, and the group that received the SRP + aPDT treatment tended to approach this value over time. After 3 days, statistically significant differences were observed between G4 and all other experimental groups, as well as versus PD+ (one-way ANOVA + Tukey's post hoc test were performed, p < 0.05). It was concluded that the adjunctive use of aPDT in combination with SRP showed the best therapeutic results in the treatment of periodontal disease in rats.

Arterial hypertension perpetuates alveolar bone loss.

Few studies have focused on the impact of hypertension on the progression of periodontitis (PD). The purpose of this study was to evaluate whether hypertension affects PD by enhancing bone loss even after the stimulus for PD induction is removed. Ligature-induced PD was created on the first mandibular molars of spontaneously hypertensive rats (SHR) and normotensive rats (Wistar Kyoto-WKY). The animals were assigned to non-ligated controls (C) and PD groups: WKY-C, WKY-PD, SHR-C, and SHR-PD. After 10 days, five animals of each group were killed and the ligatures of the other animals were removed. On the 21st day (11 days without PD induced), the remaining animals were killed. The jaws were defleshed and the amount of bone loss was measured. After 10 days, the PD groups showed more bone loss than its controls (P < .05); SHR-PD = 0.72 ± 0.05 mm, SHR-C = 0.39 ± 0.04 mm, WKY-PD = 0.75 ± 0.04 mm, and WKY-C = 0.56 ± 0.04 mm. The cumulative bone loss on day 21 (0.94 ± 0.13 mm) was significantly worse than on day 10 only in SHR-PD group (P < .05). The final bone loss differences between PD and C groups accounted for 102% (SHR) and 26% (WKY) increase in comparison with the initial control levels. Hypertension is associated with progressive alveolar bone loss even when the stimulus for PD induction is removed and it may be speculated that host condition perpetuates alveolar bone loss.

Does resveratrol favor peri-implant bone repair in rats with ovariectomy-induced osteoporosis? Gene expression, counter-torque and micro-CT analysis.

This study investigated the influence of resveratrol on peri-implant repair and its effects on bone-related markers in ovariectomy-induced osteoporosis in rats. Animals were divided into: OVX+PLAC (n = 10): ovariectomized animals treated with placebo; OVX+RESV (n = 10): OVX treated with resveratrol; OVX+PLAC+ZOL (n = 10): OVX treated with PLAC and zoledronate; OVX+RESV+ZOL (n = 10): OVX treated with RESV and ZOL; and SHOVX+PLAC (n = 10): sham ovariectomy treated with PLAC. RESV and PLAC were administrated after ovariectomy and ZOL after six weeks after OVX, until the end of experiment. One implant was inserted in each tibiae of animals 18 weeks after ovariectomy. After 4 weeks, one implant was removed for counter-torque, and peri-implant tissue was collected for mRNA quantification of several osteogenic markers by PCR. The other tibia was submitted to micro-computed tomography analysis. Reduced counter-torque values, bone-implant contact (BIC) and bone volume fraction (BV/TV), and higher bone porosity (BP) were detected in OVX+PLAC group when compared to SHOVX+PLAC (p < 0.05). OVX+RESV rats presented lower BIC, BV/TV, and trabecular number (Tb.N), and augmented BP and trabecular spacing (Tb.Sp) when compared to SHOVX+PLAC (p < 0.05). Higher Tb.N and connectivity density (Conn.Dn) and reduced Tb.Sp were observed in OVX rats treated with ZOL, independently of RESV, when compared to OVX+PLAC and OVX+RESV groups (p < 0.05), whereas the combination ZOL+RESV promoted lower BP when compared to OVT+PLAC and OVX+RESV (p < 0.05). Gene expression was not influenced by RESV (p > 0.05), whereas ZOL promoted up-regulation of BMP-2 (p<0.05). RESV did not improve peri-implant bone repair in rats with ovariectomy-induced osteoporosis.

Standardization of Animal Models and Techniques for Platelet-Rich Fibrin Production: A Narrative Review and Guideline.

Experimental research is critical for advancing medical knowledge and enhancing patient outcomes, including in vitro and in vivo preclinical assessments. Platelet-rich fibrin (PRF) is a blood by-product that has garnered attention in the medical and dental fields due to its potential for tissue regeneration and wound healing. Animal models, such as rabbits and rats, have been used to produce PRF and examine its properties and applications. PRF has demonstrated potential in the dental and medical fields for reducing inflammation, promoting tissue repair, and accelerating wound healing. This narrative review aims to compare existing evidence and provide guidelines for PRF animal research, emphasizing the importance of standardizing animal models, following ethical considerations, and maintaining transparency and accountability. The authors highlight the necessity to use the correct relative centrifugal force (RCF), standardize centrifugal calibration, and report detailed information about blood collection and centrifuge parameters for reproducible results. Standardizing animal models and techniques is crucial for narrowing the gap between laboratory research and clinical applications, ultimately enhancing the translation of findings from bench to bedside.

Probiotic consumption can modify the resilience of periodontal tissues in rats under experimental periodontitis.

BACKGROUND: This study evaluated the effects of systemic administration of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019) on experimental periodontitis (EP) in rats. METHODS: Thirty-two rats were allocated to groups C (control), C-HN019 (probiotic), EP (EP only), and EP-HN019 (EP+probiotic). From day 0, the animals of C-HN019 and EP-HN019 groups received B. lactis HN019 (1 × 109 CFU/ml) daily. On the 14th day, the animals of EP and EP-HN019 groups received silk ligature around mandibular molars. Animals were euthanized on the 28th day. Samples of oral biofilm, gingival tissues, blood serum, and mandible were obtained for microtomographic, histomorphometric, microbiological, and immunological analyses. Data were statistically analyzed (p < 0.05). RESULTS: Group EP-HN019 presented significantly less alveolar bone loss when compared with Group EP in histomorphometric and microtomographic analyses. In gingival tissue and serum, Group EP-HN019 presented lower proinflammatory/anti-inflammatory cytokines ratios than Group EP. Group EP-HN019 showed higher expression of beta-defensins and less TRAP-positive cells than Group EP. Group EP presented higher gene expression of Ifng and lower gene expression of Foxp3 when compared with Group EP-HN019 in gingival tissue. In oral biofilm, EP-HN019 group presented a lower percentage of species similar to Fusobacterium periodonticum and a higher percentage of species similar to Actinomyces gereneseriae, Actinomyces israelli, and Streptococcus gordonii when compared with Group EP. There was a significant increase of B. lactis HN019 after administration of probiotic therapy in oral biofilm of Group EP-HN019. CONCLUSION: The consumption of B. lactis HN019 promotes a protective effect against alveolar bone loss by modifying local and systemic microbiological and immunoinflammatory parameters.

Effects of Bdellovibrio bacteriovorus HD100 on experimental periodontitis in rats.

AIM: The aim of this study was to evaluate the effects of Bdellovibrio bacteriovorus HD100 on experimental periodontitis (EP) in rats. METHODS: Thirty-two rats were divided into four groups: control, C-HD100 (B. bacteriovorus), EP, and EP-HD100. On day 0, EP was induced by the placement of cotton ligatures around the mandibular first molars (MFMs) in the EP and EP-HD100 groups. In the C-HD100 and EP-HD100 groups, suspensions containing 1 × 109  PUF/ml of B. bacteriovorus HD100 were topically administered to the subgingival region of MFMs on days 0, 3, and 7. Animals were euthanized on day 14. Morphometrics analyses were performed in hemimandibles. The levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-10, IL-1ß, transforming growth factor beta (TGF-ß), macrophage colony-stimulating factor (M-CSF) and regulated on activation and normal T cell expressed and secreted (RANTES) were determined by enzymatic immunoassays in gingival tissues. Beta defensin (BD)-1, BD-2, and BD-3, Toll-like receptors (TLR)-2 and TLR-4, and a cluster of differentiation (CD)-4, CD-8 and CD-57 were analyzed by immunohistochemistry in hemimandibles. Data were statistically analyzed. RESULTS: The EP group showed greater alveolar bone loss than EP-HD100 (p < .05). The EP-HD100 group showed higher levels of MCP-1, RANTES, IL-10, and TGF-ß, lower levels of TNF-α than the EP group (p < .05). No differences were observed in IL-1ß, IL-6, and M-CSF levels between EP and EP-HD100 groups. The C-HD100 group had higher IL-6, TNF-α, RANTES, and MCP-1 levels than the control group (p < .05). Regarding BD, the EP-HD100 group showed a larger immunolabeling pattern for BD-1, BD-2, and BD-3 than the EP group (p < .05). No significant differences in the immunolabeling pattern were observed for TLR-2, TLR-4, CD-4, CD-8, and CD-57 between EP and EP-HD100 groups. CONCLUSION: The topical use of B. bacteriovorus HD100 reduces alveolar bone loss, increases expression of BD, and modulates the cytokines levels on periodontal tissues in rats with EP.