Effectiveness of a tissue conditioner containing antifungals in a rat model of denture stomatitis.

AIM: This study investigated the effectiveness of a drug-modified tissue conditioner in an animal model of denture stomatitis. METHODS AND RESULTS: Wistar rats wore a Candida albicans-contaminated palatal device for 4 days. Next, nystatin (Nys) or chlorhexidine (Chx) were added to a tissue conditioner in their raw or ß-cyclodextrin-complexed (ßCD) forms at their minimum inhibitory concentrations. As controls, one group was not subjected to any procedure (NC), one group used sterile devices, one group had denture stomatitis but was not treated (DS), and another had the devices relined with the tissue conditioner without the addition of any drug (Soft). After 4 days of treatment, treatment effectiveness was assessed visually, histologically, and through CFU count, and myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats from the Soft, Nys, Nys:ßCD, and Chx groups presented a significant decrease in the microbial load compared with the untreated group. Treatment groups showed lower MPO and NAG activity compared to the non-treated group. CONCLUSIONS: The addition of antifungals to a soft tissue conditioner can be a promising approach for denture stomatitis treatment.

A novel rat model of denture stomatitis and the role of antibiotics in the development of the disease.

This study compared different conditions to establish a rat model of denture stomatitis. Immunocompetent Wistar rats were divided into two groups (n = 35): Tetracycline = administration of 0.83 mg/ml of tetracycline hydrochloride 7 days before induction of denture stomatitis and amoxicillin = administration of 0.156 mg/ml of amoxicillin with clavulanic acid 4 days before induction of denture stomatitis. A suspension of Candida albicans was inoculated on the palate followed by the use of a palatal device contaminated with C. albicans inoculum for 4 days to induce denture stomatitis. As controls, some rats were not submitted to any procedure or used a sterile palatal device for 4 days. The development of denture stomatitis was confirmed by visual analysis, colony-forming units per milliliter (CFU/ml) count, histopathological and immunohistochemical analyses, and through myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats were euthanized right after device removal (T0), 4 (T4), or 6 (T6) days after device removal. Tetracycline improved the development of the disease, with more severe clinical signs at T0. Similar results were observed in the CFU/ml count and in the histometric and immunohistochemical analyses. Higher MPO expression was detected in the palates of the tetracycline group (P = .006). Despite the subtle differences between antibiotics, tetracycline showed better results in inducing and maintaining denture stomatitis for at least 4 days after device removal.

Denture stomatitis is an oral inflammatory disease with high recurrence rates. Different animal models have been reported in the literature, but some gaps still need to be addressed. A reproducible in vivo model should be established to test new treatment approaches.

Prospective tomographic evaluation of autogenous bone resorption harvested from mandibular ramus in atrophic maxilla.

Autogenous bone is considered the criterion standard for grafting procedures of severely resorbed alveolar ridges. However, the rate of autogenous graft resorption remains controversial. The aim of this study was to evaluate the mandibular graft resorption with cone beam computed tomography after 10 and 180 days of augmentation procedures in the atrophic maxilla. Twenty-two patients received 36 autogenous bone grafts harvested from the mandibular ramus. Tomographical evaluations were carried out after 10 (T1) and 180 (T2) days of augmentation procedures to obtain bone grafts area measurements. After 10 days postoperatively (T1), the mean area of bone graft was 81.38 mm (range, 46.33-113.73 mm), whereas, after 180 days postoperatively (T2), the mean area of bone graft was 66.13 mm (range, 33.51-101.93 mm). The mean percentage variation of graft resorption between T1 and T2 was 18.38%. Autogenous bone blocks harvested from the mandibular ramus presented a reduction of 18.38% in the measurement areas after the augmentation procedures in the atrophic maxilla. Therefore, the use of autogenous bone blocks remains as a viable and predictable procedure for the rehabilitation of the atrophic maxillae. Thus, other studies must be carried out to improve the knowledge on the bone graft resorption, which may serve as a basis for the development of more effective strategies for the rehabilitation of patients with an atrophic maxilla.

Influence of implant drill materials on wear, deformation, and roughness after repeated drilling and sterilization.

PURPOSE: The aim of this study was to evaluate deformation, roughness, and mass loss of stainless steel, diamond-like carbon (DLC)-coated and zirconia drills after multiple osteotomies with sterilization procedures. MATERIALS AND METHODS: Drilling procedures were performed using stainless steel (G1), DLC-coated (G2), and zirconia (G3) drills. All groups were divided in subgroups 1, 2, 3, 4, and 5, corresponded to drills used 0, 10, 20, 30, and 40 times, respectively. RESULTS: No significant differences in mass and roughness were detected among all groups and subgroups. In SEM images, all groups revealed signs of wear while coating delamination was detected in G2. Drills from G1 displayed more irregular surface, whereas cutting edges were more regular in G3. CONCLUSION: Zirconia drills presented more regular surfaces whereas stainless steel drills revealed more severe signs of wear. Further studies must be performed to evaluate the putative influence of these findings in heat generation.

Performance of panoramic radiography compared with computed tomography in the evaluation of pathological changes in the maxillary sinuses: a systematic review and meta-analysis.

OBJECTIVE: A systematic review was performed to evaluate the performance of panoramic radiography (PR) vs CT or cone beam CT (CBCT) in the diagnosis of pathological maxillary sinuses. METHODS: This review was registered in the PROSPERO database under the number CRD42020211766. Observational studies that compared PR with CT/CBCT were used to evaluate pathological changes in the maxillary sinuses. A complete search of seven primary databases and gray literature was carried out. The risk of bias was assessed according to the Newcastle-Ottawa tool, and the GRADE tool was used to assess the quality of evidence. A binary meta-analysis was performed to assess the effectiveness of evaluating pathological alterations in the maxillary sinuses in PR and CT/CBCT. RESULTS: Seven studies were included in our study, out of which four were included in a quantitative analysis. All studies were classified as low risk of bias. Five studies compared PR with CBCT and two studies compared PR to CT. The most common pathological alteration in maxillary sinuses reported was mucosal thickening. CT/CBCT was seen to be the most effective method for assessing pathological changes in the maxillary sinus when compared to PR (RR = 0.19, 95% confidence interval [CI] = 0.05 to 0.70, p = 0.01). CONCLUSION: CT/CBCT are the most appropriate imaging methods to evaluate pathological changes in the maxillary sinuses, while PR is still limited in the evaluation of these changes being considered only for initial diagnosis.

Microtomographic, histomorphometric, and molecular features show a normal alveolar bone healing process in iNOS-deficient mice along a compensatory upregulation of eNOS and nNOS isoforms.

METHODOLOGY: Inducible nitric oxide synthase (iNOS) is one of the enzymes responsible for the synthesis of nitric oxide (NO), which is an important signaling molecule with effects on blood vessels, leukocytes, and bone cells. However, the role of iNOS in alveolar bone healing remains unclear. This study investigated the role of iNOS in alveolar bone healing after tooth extraction in mice. C57Bl/6 wild type (WT) and iNOS genetically deficient (iNOS-KO) mice were subjected to upper incision tooth extraction, and alveolar bone healing was evaluated by micro-computed tomography (µCT) and histological/histomorphometric, birefringence, and molecular methods. RESULTS: The expression of iNOS had very low control conditions, whereas a significant increase is observed in healing sites of WT mice, where iNOS mRNA levels peak at 7d time point, followed by a relative decrease at 14d and 21d. Regarding bone healing, both WT and iNOS-KO groups showed the usual phases characterized by the presence of clots, granulation tissue development along the inflammatory cell infiltration, angiogenesis, proliferation of fibroblasts and extracellular matrix synthesis, bone neoformation, and remodeling. The overall micro-computed tomography and histomorphometric and birefringence analyses showed similar bone healing readouts when WT and iNOS-KO strains are compared. Likewise, Real-Time PCR array analysis shows an overall similar gene expression pattern (including bone formation, bone resorption, and inflammatory and immunological markers) in healing sites of WT and iNOS-KO mice. Moreover, molecular analysis shows that nNOS and eNOS were significantly upregulated in the iNOS-KO group, suggesting that other NOS isoforms could compensate the absence of iNOS. CONCLUSION: The absence of iNOS does not result in a significant modulation of bone healing readouts in iNOS-KO mice. The upregulation of nNOS and eNOS may compensate iNOS absence, explaining the similar bone healing outcome in WT and iNOS-KO strains.

Analysis of IL1 gene polymorphisms and transcript levels in periodontal and chronic kidney disease.

UNLABELLED: Chronic kidney disease (CKD) and periodontitis (PD) are complex inflammatory disturbances, influenced by genetic factors. Interleukin (IL)-1 genes code for inflammatory mediators involved in the physiopathogenesis of both diseases. Functional polymorphisms in IL1 genes modulate cytokine levels and have been associated with susceptibility to immune-inflammatory conditions. OBJECTIVES: The aim of this study was investigate the association of functional IL1 gene polymorphisms and transcript levels with susceptibility to CKD and PD. DESIGN: The sample consisted of 246 individuals, mean age 44.8 years, divided into: group 1 (64 patients without CKD and without PD), group 2 (58 without CKD and with PD), group 3 (52 with CKD and without PD) and group 4 (72 with CKD and with PD). DNA was obtained from cells of oral mucosa and polymorphisms IL1AC-889T, IL1BC-511T, IL1BC+3954T and IL1RN (intron 2) were analyzed by PCR-RFLP. Transcript levels from gingival tissues were analyzed by real-time PCR. RESULTS: IL1RN(*)1 allele was associated with almost 4-fold increased risk for CKD (OR 3.92 95% CI=1.6-9.4, p=0.002). IL1RN(*)2 allele was associated with 3-fold increased risk for PD in CKD patients (OR 3.08 95% CI=1.2-7.9, p=0.019). Allele T for polymorphism IL1B+3954 was associated with CKD in PD patients (OR 2.28 95% CI=1.1-4.7, p=0.019). Significantly increased levels of transcripts of IL1A, IL1B and IL1RN genes were found in PD patients. CONCLUSIONS: It was observed an evidence for association of IL1B and IL1RN alleles with susceptibility to CKD and PD. Higher levels of IL1 gene transcripts were found in PD patients.

Effect of pentoxifylline and α-tocopherol on medication-related osteonecrosis of the jaw in rats: Before and after dental extraction.

OBJECTIVE: Evaluate the effect of pentoxifylline and α-tocopherol administration in the prevention or treatment of medication-related jaw osteonecrosis (MRONJ). METHODOLOGY: Sixty Wistar rats were divided into three prevention (C-prev, BP-prev and BP/PT-prev) and three treatment groups (C-treat, BP-treat and BP/PT-treat), n = 10. The animals in the BP-prev, BP/PT-prev, BP-treat and BP/PT-treat groups received zoledronic acid (0.1 mg/kg) for 12 weeks, while the animals in the C-prev and C-treat groups received saline solution. At week 6, all animals underwent tooth extraction. Between week 5 and week 12, the BP/PT-prev group was treated with pentoxifylline (50 mg/kg/day) and α-tocopherol (80 mg/kg/day), with euthanasia at the end of week 12. The BP/PT-treat group received the same drug protocol, but it was performed between week 12 and week 16, with euthanasia at the end of week 16. Afterwards, the presence of osteonecrosis was evaluated by clinical analysis, radiographic and histological. RESULTS: BP/PT-treat group showed a reduction in the histological incidence of osteonecrosis by 50%, decrease the percentage of empty osteocyte gaps and the necrotic area, decrease the presence of bone sequestration and increase the number of osteocytes and alveolar blood flow (p < 0.05). However, BP/PT-prev group showed only a reduction in the necrotic area percentage when compared to BP-prev (p < 0.05). CONCLUSIONS: Pentoxifylline and α-tocopherol administration before tooth extraction was not effective in preventing MRONJ. However, this drug protocol was able to reduce MRONJ manifestation when administrate after discontinuation of bisphosphonate, thus it can be considered as a viable strategy for the treatment of this pathological condition.

Implant Osseointegration in Grafted Autogenous Bone Blocks Fixed with Screws and Cyanoacrylate-Based Adhesive: Histomorphometric and Micro-CT Analyses.

PURPOSE: To evaluate implant osseointegration in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Also, grafted bone fixed either with an adhesive or screw was evaluated. MATERIALS AND METHODS: Two surgical defects in the parietal region of rabbits (n = 12) were performed in each animal. Autogenous bone blocks obtained were fixed anteriorly with a screw or cyanoacrylate-based adhesive. After 30 and 45 days of grafting procedures, implants were placed in bone blocks. Histomorphometric and microcomputed tomography (micro-CT) analyses of the implant area were performed at 30 days after implant surgery in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric analyses of bone-grafted areas were performed at 60 and 75 days in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric evaluations were carried out in implant and grafted bone areas. The micro-CT parameters evaluated were bone-to-implant contact, bone area fraction occupancy, bone volume fraction, trabecular thickness, trabecular separation, and trabecular number. RESULTS: No differences were observed in the micro-CT parameters for the screw and adhesive groups in all experimental periods. However, an increased quantity of immature bone volume was observed on the adhesive group in the grafted area after 75 days. The grafted area in the screw group (75 days) presented a decrease in the volume density of the immature bone compared with the screw group (60 days). There were no differences in both groups and experimental periods in soft tissue in the grafted area. CONCLUSION: No differences were observed in the osseointegration of implants placed in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Therefore, osseointegration in autogenous bone fixed with cyanoacrylate-based adhesive is viable.

Absence of medication-related jaw osteonecrosis after treatment with strontium ranelate in ovariectomized rats.

This study aimed to evaluate the potential of strontium ranelate (SR) in medication-related jaw osteonecrosis (MRONJ) after tooth extraction in ovariectomized rats. Thirty ovariectomized rats were divided into three groups (n = 10): bisphophonate (BP) group (zoledronic acid; 0.4 mg/kg/week), SR group (625 mg/kg/day), and control group (saline solution). The lower first molars were extracted after 60 days of drug therapy. Drug administration was continued for another 30 days after tooth extraction. The mandibles were subjected to clinical, histological, radiographic, and microtomographic evaluations. Only the BP group showed clinical changes, characterized by the presence of 70% (n = 7) and 20% (n = 2) of ulcers and extraoral fistulas. Radiographic evaluation demonstrated bone sequestration only in the BP group (n = 7, 70%). Microtomographic analysis revealed increased bone porosity after ovariectomy, particularly in the the control group (p < 0.05). The BP group showed a higher bone surface density, bone volume, and trabecular number than SR and control groups, but with less trabecular separation (p < 0.05). All the animals in the BP group demonstrated histological osteonecrosis. There was no evidence of osteonecrosis in the control and SR groups, which was characterized by the absence of empty osteocyte gaps and associated with the gradual healing of the extraction area. Also, an increased number of blood vessels and a reduced number of osteoclasts were observed in the SR group (p < 0.05). Therefore, SR treatment increased angiogenesis and osteoclastogenesis in the healing socket and was not associated with MRONJ development after tooth extraction in ovariectomized rats.

Histological Comparison between Biphasic Calcium Phosphate and Deproteinized Bovine Bone on Critical-Size Bone Defects.

The limited options for bone repair have led to an extensive research of the field and the development of alloplastic and xenogeneic grafts. The purpose of this study was to evaluate bone repair with two bone substitutes: deproteinized bovine bone (DBB) and biphasic calcium phosphate ceramic (BCP) in critical-size defect. A total of 8-mm defects were made in the parietal bones of rabbits (n=12). The animals were divided into three experimental groups: sham (defect filled with a blood clot), DBB (defect filled with DBB), and BCP (defect filled with BCP). After the experimental periods of 15 and 45 days, the animals were euthanized and submitted to histomorphometric analysis. The total defect area, mineralized tissue area, biomaterial area, and soft tissue area were evaluated. A greater amount of immature bone tissue and biomaterial particles were observed in the BCP group compared to DBB and sham at 45 days (p<0.05). There was no difference in the qualitative pattern of bone deposition between DBB and BCP. However, the sham group did not show osteoid islands along with the defect, presenting a greater amount of collagen fibers as well in relation to the DBB and BCP groups. There was a greater number of inflammatory cells in the DBB at 45 days compared to BCP and sham groups. In conclusion, BCP and DBB are options for optimizing the use of bone grafts for maxillofacial rehabilitation. Bone defects treated with BCP showed greater deposition of bone tissue at 45 days.

Effects of low-dose aspirin on the osseointegration process in rats.

BACKGROUND: Several drugs are capable of promoting changes in bone metabolism. The aim of this study was to evaluate the effect of long-term low-dose aspirin (LDA) therapy on implant osseointegration. METHODS: Male Wistar rats were divided into 4 groups (n = 8/group) according to oral gavage solution received prior (42 days) to the implant surgery on the tibia. The control group was treated with saline solution for 7 (CG-7) and 28 (CG-28) days. The use of low-dose aspirin was performed in AG groups (6.75 mg/kg of aspirin) for 7 (AG-7) and 28 (AG-28) days. After experimental periods, histomorphometric evaluation of bone-to-implant contact (BIC) and the bone area between threads (BABT) was performed. RESULTS: Reduced BIC values were detected in AG-7 (62.8% ± 17.1) group compared to AG-28 (91.9% ± 5.4), CG-7 (82.7% ± 15.2), and CG-28 (89.9% ± 9.7). BABT evaluation revealed lower values in AG-7 (70.9% ± 15.2) compared to AG-28 (95.4% ± 3.7) and CG-28 (87.1% ± 10.2) groups. CONCLUSIONS: The treatment with low doses of aspirin promoted a discrete inhibitory effect in the early stages (7 days) of repair after implant placement, specifically in the bone deposition. However, these effects were not detected in the late stages (28 days), considering BIC and BABT parameters.

Association of human T lymphotropic virus 1 amplification of periodontitis severity with altered cytokine expression in response to a standard periodontopathogen infection.

BACKGROUND: Periodontal diseases (PDs) are infectious diseases in which periodontopathogens trigger chronic inflammatory and immune responses that lead to tissue destruction. Recently, viruses have been implicated in the pathogenesis of PDs. Individuals infected with human T lymphotropic virus 1 (HTLV-1) present with abnormal oral health and a marked increased prevalence of periodontal disease. METHODS: In this study, we investigated the patterns of periodontopathogen infection and local inflammatory immune markers in HTLV-1-seropositive individuals with chronic periodontitis (CP/HTLV-1 group) compared with HTLV-1-seronegative individuals with chronic periodontitis (CP group) and periodontally healthy, HTLV-1-seronegative individuals (control group). RESULTS: Patients in the CP/HTLV-1 group had significantly higher values of bleeding on probing, mean probing depth, and attachment loss than patients in the CP group. The expression of tumor necrosis factor alpha and interleukin (IL) 4 was found to be similar in the CP and CP/HTLV-1 groups, whereas IL-12 and IL-17 levels trended toward a higher expression in the CP/HTLV-1 group. A significant increase was seen in the levels of IL-1beta and interferon gamma in the CP/HTLV-1 group compared with the CP group, whereas expression of the regulatory T cell marker FOXp3 and IL-10 was significantly decreased in the lesions from the CP/HTLV-1 group. Interestingly, similar frequency and/or load of periodontopathogens (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans) and frequency of viruses (herpes simplex virus 1, human cytomegalovirus, and Epstein-Barr virus) characteristically associated with PDs were found in the CP/HTLV and CP groups. CONCLUSIONS: HTLV-1 may play a critical role in the pathogenesis of periodontal disease through the deregulation of the local cytokine network, resulting in an exacerbated response against a standard periodontopathogen infection.

Regulatory T cells attenuate experimental periodontitis progression in mice.

AIMS: The aim of this study was to identify the presence and characterize the function of regulatory T cells (Tregs) in experimental periodontitis in mice. MATERIAL AND METHODS: C57Bl/6 mice infected with Actinobacillus actinomycetemcomitans, treated or not with anti-glucocorticoid-inducible tumour necrosis factor receptor (anti-GITR) to inhibit Tregs function, were analysed regarding inflammatory cell and Tregs influx, alveolar bone loss and cytokine expression/production (analysed by real-time polymerase chain reaction and ELISA) throughout experimental periodontitis. RESULTS: A. actinomycetemcomitans inoculation in mice resulted in periodontal disease characterized by marked alveolar bone loss and an influx of inflammatory cells. Flow cytometry evaluation of inflammatory cells demonstrated an increased number of CD4(+)CD25(+) and CD4(+)FOXp3(+) cells, characterizing the presence of Tregs in the periodontal environment in a late stage after infection. Tregs-associated cytokines interleukin-10 (IL-10), cytotoxic T lymphocyte-associated molecule 4 (CTLA-4) and transforming growth factor-beta (TGF-beta) were found to be expressed/produced in a kinetics that resembles Tregs migration. Treatment with anti-GITR, which inhibits Tregs function, showed increased alveolar bone loss and inflammatory cell migration. A reduction in IL-10, CTLA-4 and TGF-beta levels was also observed, while interferon-gamma, tumour necrosis factor-alpha and receptor activator for nuclear factor kappaB ligand levels were increased. However, bacterial load and C-reactive protein serum did not show any differences. CONCLUSION: Taken together, our results showed that the presence of Treg cells attenuates the severity of experimental periodontitis without impairment in the control of infection.

Down-regulation of expression of osteoblast and osteocyte markers in periodontal tissues associated with the spontaneous alveolar bone loss of interleukin-10 knockout mice.

The aim of this study was to unravel the mechanisms by which interleukin (IL)-10, a potent pleiotropic cytokine, modulates alveolar bone homeostasis in C57BL/6 wild-type (WT) and IL-10 knockout (IL-10 KO) mice, evaluated at 8, 24, and 48 wk of age. Interleukin-10 KO mice presented significant alveolar bone loss when compared with WT mice, and this was not associated with changes in leukocyte counts or bacterial load. The levels of expression of messenger RNA (mRNA) for tumor necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6, transforming growth factor-beta (TGF-beta), receptor activator of nuclear factor kappaB ligand (RANKL), osteoprotegerin (OPG), and matrix metalloproteinase 13 (MMP13) were similar between both strains, whereas a significant decrease of tissue inhibitor of metalloproteinase 1 (TIMP1) mRNA expression was found at 48 wk in IL-10 KO mice. The osteoblast markers core binding factor alpha1 (CBFA1) and type I collagen (COL-I) were expressed at similar levels in both strains, whereas the levels of alkaline phosphatase (ALP) and osteocalcin (OCN), and those of the osteocyte markers phosphate-regulating gene endopeptidases (PHEX) and dentin matrix protein 1 (DMP1) were significantly lower in IL-10 KO mice. Our results demonstrate that the alveolar bone loss in the absence of IL-10 was associated with a reduced expression of osteoblast and osteocyte markers, an effect independent of microbial, inflammatory or bone-resorptive pathways.

Osteoconductivity of Biphasic Calcium Phosphate Ceramic Improves New Bone Formation: A Histologic, Histomorphometric, Gene Expression, and Microcomputed Tomography Study.

PURPOSE: The purpose of this study was to evaluate bone repair with two bone substitutes, deproteinized bovine bone and biphasic calcium phosphate ceramics, associated with autogenous bone. MATERIALS AND METHODS: The experimental groups were as follows: autogenous bone only (AB), autogenous bone/deproteinized bovine bone (1:1), and autogenous bone/biphasic calcium phosphate ceramic (1:1). After 30, 60, and 90 days, animals were euthanized and samples were collected for microcomputed tomography (micro-CT), histologic, histomorphometric, and expression analyses of VEGFA, RUNX2, ALP, COL1A1, OCN, PHEX, RANKL, and OPG genes by real-time polymerase chain reaction (PCR) array. RESULTS: Histomorphometric analysis showed no difference in the amount of immature bone between AB and AB/biphasic calcium phosphate ceramic at 30 and 60 days. There was less mature bone formation in the AB/deproteinized bovine bone at 60 days compared with AB/biphasic calcium phosphate ceramic and AB, and a lower amount of immature bone in the AB/deproteinized bovine bone at 30 and 60 days compared with the AB (P ≤ .05). Micro-CT analysis showed higher immature bone volume (BVI) in the AB/biphasic calcium phosphate ceramic at 60 days and lower BVI at 90 days (P ≤ .05). Molecular analysis showed a lower expression of all genes in the AB/deproteinized bovine bone and AB/biphasic calcium phosphate ceramic compared with AB at all time points. A greater expression of RANKL was found in the AB/deproteinized bovine bone compared with AB/biphasic calcium phosphate ceramic at 30 days (P ≤ .05), and a lower expression of the OC, RUNX2, and ALP genes in AB/deproteinized bovine bone and AB/biphasic calcium phosphate ceramic was found compared with AB at all time points (P ≤ .05). CONCLUSION: The use of biphasic calcium phosphate ceramic resulted in greater immature bone formation than deproteinized bovine bone at an early assessment. The studied bone regeneration genes were downregulated in comparison to the control.

Experimental Acute Sepsis Reduced Number of Osteocalcin Immunolabeled Cells in Periodontal Ligament.

The aim of this study was to evaluate the effect of acute sepsis in the periodontal ligament, alveolar and furcation bone in absence of periodontitis induction through histological and immunohistochemical analyses. A septic rat model was established by cecal ligation and puncture (CLP). Twelve rats were randomly divided into CLP (n=6) and Sham (n=6) groups. The animals were euthanized at 24 h and hemimandibles were submitted to histomorfometric (bone matrix, collagenous fibers, fibroblasts, osteocytes, inflammatory cells, and blood vessels) and immunohistochemical (BMP-2/4, RANKL and osteocalcin) evaluation in alveolar bone, furcation bone and periodontal ligament. Our results demonstrated that histomorphometric parameters were similar in alveolar bone, furcation bone and periodontal ligament of Sham and CLP rats. Regarding to immunohistochemical analyses, the number of BMP-2/4 and RANKL immunolabeled cells was also similar in both groups. Furthermore, it was detected a reduction in the osteocalcin immunolabeled cells in periodontal ligaments of CLP compared to Sham rats (p=0.0014). In conclusion, the acute sepsis induction resulted in reduced number of osteocalcin labelled cells in periodontal ligament region. Moreover, no significant histological differences were observed in the periodontium of rats under acute sepsis. Considering the role of osteocalcin in bone remodeling, the study contributes to revealing the importance of careful periodontal evaluation in the presence of sepsis.

The broad effects of the functional IL-10 promoter-592 polymorphism: modulation of IL-10, TIMP-3, and OPG expression and their association with periodontal disease outcome.

Periodontal diseases are infectious diseases, in which periodontopathogens trigger chronic inflammatory and immune responses that lead to tissue destruction. It occurs through the generation of metalloproteinases and the activation of bone resorption mechanisms. Anti-inflammatory cytokines such as IL-10 seem to attenuate periodontal tissue destruction through the induction of tissue inhibitors of metalloproteinases (TIMPs) and the inhibitor of osteoclastogenesis osteoprotegerin (OPG). A high individual variation in levels of IL-10 mRNA is verified in periodontitis patients, which is possibly determined by genetic polymorphisms. In this study, the IL-10 promoter -592C/A single nucleotide polymorphism (SNP), which is associated with a decrease in IL-10 production, was analyzed by RFLP in 116 chronic periodontitis (CP) patients and 173 control (C) subjects, and the IL-10, TIMPs, and OPG mRNA expression levels in diseased gingival tissues were determined by real-time-PCR. The IL-10-592 SNP CA (P=0.0012/OR=2.4/CI:1.4-4.1), AA (P=0.0458/OR=2.3/CI:1.1-4.9), and CA+AA (P=0.0006/OR=2.4/CI:1.4-3.4) genotypes and the allele A (P=0.0036/OR=1.7/CI:1.2-2.4) were found to be significantly more prevalent in the CP group when compared with control subjects. Both CA and AA genotypes were associated with lower levels of IL-10, TIMP-3, and OPG mRNA expression in diseased periodontal tissues and were also associated with disease severity as mean pocket depth. Taken together, the results presented here demonstrate that IL10-592 SNP is functional in CP, being associated with lower levels of IL-10 mRNA expression, which is supposed to consequently decrease the expression of the downstream genes TIMP-3 and OPG, and influence periodontal disease outcome.