Can SARS-CoV-2 screening in oral biopsies aid epidemiological surveillance?

BACKGROUND: Three years after the first confirmed COVID-19 case in Brazil, the outcomes of Federal government omissions in managing the crisis and anti-science stance heading into the pandemic have become even more evident. With over 36 million confirmed cases and nearly 700 000 deaths up to January 2023, the country is one of the hardest-hit places in the world. The lack of mass-testing programs was a critical broken pillar responsible for the quick and uncontrolled SARS-CoV-2 spread throughout the Brazilian population. Faced with this situation, we aimed to perform the routine SARS-CoV-2 screening through RT-qPCR of oral biopsies samples to aid in the asymptomatic epidemiological surveillance during the principal outbreak periods. METHODS: We analyzed 649 formalin-fixed paraffin-embedded oral tissue samples from five important oral and maxillofacial pathology laboratories from the north, northeast, and southeast geographic regions of Brazil. We also sequenced the whole viral genome of positive cases to investigate SARS-CoV-2 variants. RESULTS: The virus was detected in 9/649 analyzed samples, of which three harbored the Variant of Concern Alpha (B.1.1.7). CONCLUSION: Although our approach did not value aiding asymptomatic epidemiological surveillance, we could successfully identify a using FFPE tissue samples. Therefore, we suggest using FFPE tissue samples from patients who have confirmed diagnosis of SARS-CoV-2 infection for phylogenetic reconstruction and contraindicate the routine laboratory screening of these samples as a tool for asymptomatic epidemiological surveillance.

Oral carcinogenesis triggers a nociceptive behavior and c-Fos expression in rats' trigeminal pathway.

OBJECTIVE: To recognize changes that occur along the trigeminal pathway in oral cancer in order to establish an effective approach to pain control. METHODS: Wistar rats were divided into control and 4-NQO groups for 8, 12, 16, or 20 weeks. 4-NQO suspension was administered on the animals' tongues. Mechanical hyperalgesia, assessment of facial expressions, and an open-field test were performed. After euthanasia, the animals' tongues were removed for macro- and microscopic analysis. c-Fos expression was analyzed in the trigeminal pathway structures. RESULTS: 4-NQO induced time-dependent macroscopic lesions that were compatible with neoplastic tumors. Histopathological analysis confirmed oral squamous cell carcinoma in 50% of the animals on the 20th week. There was a significant nociceptive threshold reduction during the first two weeks, followed by a threshold return to the baseline levels, decreasing again from the 12th week. Facial nociceptive expression scores were observed on the 20th week, while increased grooming and exploratory activity were observed on the 8th week. Trigeminal ganglion showed an increased c-Fos immunoexpression on the 20th week, and in the trigeminal subnucleus caudalis, it occurred on the 16th and 20th. The long-term carcinogenic exposure caused changes in the nociceptive behavior and c-Fos expression in the rats' trigeminal pathway.

Bisphosphonate-related osteonecrosis induced change in alveolar bone architecture in rats with participation of Wnt signaling.

OBJECTIVE: This work aimed to study the role of inflammation in medication-related osteonecrosis of the jaw (MRONJ) in rats with focus on Wnt signaling. METHODS: A total of 36 female Wistar rats (12 weeks ± 200 g) were divided into 2 groups (n = 6) in 3 experiments: saline (SAL) and zoledronic acid (ZOL). For MRONJ induction, rats received 0.1 mg/kg of ZOL (ip) 3×/week for 9 weeks. Animals from the SAL group received 0.1 mg/kg of 0.9% SAL, ip 3×/week for 9 weeks. On the 8th week, 3 left upper molars were extracted, and on the 11th week, they were euthanized. Maxillae were evaluated by macroscopic and histopathological analyses; scanning electron microscopy (SEM); immunohistochemistry for DKK-1, Wnt 10b, and caspase-3; and Raman spectrometry. Gingiva was also collected for TNF-α e IL-1ß quantification. RESULTS: Bone necrosis was confirmed by healing impairment, reduced number of viable osteocytes, increased caspase-3 immunoexpression, and increased number of empty lacunae (p < 0.05). ZOL enhanced inflammation and increased gingival levels of IL-1ß and TNF-α (p < 0.05). Irregular indentations were seen on bone after ZOL administration. Bone necrosis was marked by reduced amount of total and type I collagen. ZOL reduced the mineral/matrix ratio and increased carbonate/phosphate ratio. It was observed a significant reduction on Wnt10b and beta-catenin immunolabeling in the bone tissue of ZOL group. CONCLUSION: In summary, MRONJ model caused bone necrosis due to intense inflammation. Wnt signaling seems to play an important role in this process. CLINICAL RELEVANCE: New therapeutic strategies focusing on Wnt pathway can provide an interesting approach for future treatments.

Loss of heterozygosity and immunoexpression of PTEN in oral epithelial dysplasia and squamous cell carcinoma.

INTRODUCTION: Oral epithelial dysplasia (OED) is a risk factor for developing subsequent oral squamous cell carcinoma (OSCC). Loss of heterozygosity (LOH) profiles have been validated as risk predictors of malignant transformation of OED. It is still unclear if Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) allelic loss also occurs in initial stage malignant lesions and if the allelic loss is involved as one of the mechanisms of oral carcinogenesis. Thus, this study objective investigate LOH of PTEN gene and the immunohistochemical expression of the protein in OED and OSCC samples. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded samples of 19 OEDs and 16 OSCCs were included to immunohistochemistry and LOH analysis. Two polymorphic microsatellite markers (AFMA086WG9 and D10S1765) located in chromosome 10 were used in this study for LOH analysis. For immunohistochemical analysis, 5 random fields with 400× magnification were evaluated quantitatively and qualitatively in epithelial and neoplastic cells. RESULTS: AFMA086WG9 marker only demonstrated LOH in OEDs cases (10.5%). D10S1765 marker demonstrated LOH in 57.2% of OEDs and 50% of OSCCs. Higher nuclear immunostaining was detected in cases of OSCCs when compared to OEDs (p < .001) and there was strong cytoplasmic immunoexpression in OSCCs (p < .045). CONCLUSIONS: We provide evidence that the allelic loss of PTEN is present in premalignant oral lesions and OSCCs, however the LOH of PTEN does not seems to influence its protein expression.

Immunoexpression of canonical Wnt and NF-κB signaling pathways in the temporomandibular joint of arthritic rats.

OBJECTIVE: To investigate the participation of canonical Wnt and NF-κB signaling pathways in an experimental model of chronic arthritis induced by methylated bovine serum albumin (mBSA) in rat temporomandibular joint (TMJ). MATERIALS AND METHODS: Wistar rats were sensitized by mBSA+Complete Freund Adjuvant (CFA)/Incomplete Freund Adjuvant (IFA) on the first 14 days (1 ×/week). Subsequently, they received 1, 2 or 3 mBSA or saline solution injections into the TMJ (1 ×/week). Hypernociceptive threshold was assessed during the whole experimental period. 24 h after the mBSA injections, the TMJs were removed for histopathological and immunohistochemical analyses for TNF-α, IL-1ß, NF-κB, RANKL, Wnt-10b, ß-catenin and DKK1. RESULTS: The nociceptive threshold was significantly reduced after mBSA injections. An inflammatory infiltrate and thickening of the synovial membrane were observed only after mBSA booster injections. Immunolabeling of TNF-α, IL-1ß and Wnt-10b was increased in the synovial membrane in arthritic groups. The immunoexpression of nuclear ß-catenin was significantly higher only in the group that received 2 booster TMJ injections. However, NF-κB, RANKL and DKK1 immunoexpression were increased only in animals with 3 mBSA intra-articular injections. CONCLUSION: Our results suggest that canonical Wnt and NF-κB signaling pathways participate in the hypernociception and inflammatory response in TMJ synovial membrane during the development of rheumatoid arthritis in rats.

BRAFV600E mutation in the diagnosis of unicystic ameloblastoma.

BACKGROUND: Unicystic ameloblastoma, an odontogenic neoplasm, presents clinical and radiographic similarities with dentigerous and radicular cysts, non-neoplastic lesions. It is not always possible to reach a final diagnosis with the incisional biopsy, leading to inappropriate treatment. The BRAFV600E activating mutation has been reported in a high proportion of ameloblastomas. The purpose of the study was to assess the utility of the detection of the BRAFV600E mutation in the differential diagnosis of unicystic ameloblastoma with dentigerous and radicular cysts. METHODS: Twenty-six archival samples were included, comprising eight unicystic ameloblastomas (UAs), nine dentigerous and nine radicular cysts. The mutation was assessed in all samples by anti-BRAFV600E (clone VE1) immunohistochemistry (IHC) and by TaqMan mutation detection qPCR assay. Sanger sequencing was further carried out when samples showed conflicting results in the IHC and qPCR. RESULTS: Although all UAs (8/8) showed positive uniform BRAFV600E staining along the epithelial lining length, the mutation was not confirmed by qPCR and Sanger sequencing in three samples. Positive staining for the BRAFV600E protein was observed in one dentigerous cyst, but it was not confirmed by the molecular methods. Furthermore, 2/9 dentigerous cysts and 2/9 radicular cysts showed non-specific immunostaining of the epithelium or plasma cells. None of the dentigerous or radicular cysts cases presented the BRAFV600E mutation in the qPCR assay. CONCLUSIONS: The BRAFV600E antibody (clone VE1) IHC may show non-specific staining, but molecular assays may be useful for the diagnosis of unicystic ameloblastoma, in conjunction with clinical, radiological and histopathological features.

Dual effects of a lectin from the green seaweed Caulerpa cupressoides var. lycopodium on inflammatory mediators in classical models of inflammation.

OBJECTIVE: Wide biotechnological investigations of only a limited number of seaweed lectins have been performed. We previously demonstrated the anti-nociceptive and anti-inflammatory effects of a lectin isolated from the green seaweed Caulerpa cupressoides var. lycopodium (CcL). Herein, we further studied the mechanisms of action of CcL. METHODS: Classical acute inflammation models induced by different flogistic agents were used to evaluate the anti-inflammatory action of CcL. CcL was injected locally into the rat paw to verify a possible pro-inflammatory outcome. RESULTS: CcL (0.1, 1 or 10 mg/kg; i.v.) reduced the carrageenan-induced rat paw edema and neutrophilic infiltration, which was not altered by either mucin (inhibitor of CcL carbohydrate-binding site) or ZnPP-IX (specific HO-1 inhibitor). Immunohistochemical analyses showed that CcL (1 mg/kg) reduced the expression of the cytokines IL-1ß, TNF-α, IL-6 and COX-2. CcL (0.1, 1 or 10 mg/kg) inhibited dextran, and CcL (1 mg/kg) inhibited histamine-induced rat paw edema. Both effects were reversed by mucin inhibition. CcL (1 mg/kg) was ineffective for the treatment of serotonin- and bradykinin-induced rat paw edema. When injected via the i.pl. route, CcL (10 mg/kg) elicited rat paw edema involving a wide range of mediators. CONCLUSIONS: The anti-inflammatory action of CcL involves the inhibition of IL-1ß, TNF-α, IL-6 and COX-2 expression and histamine H1 receptors. When locally administered, CcL exerts pro-inflammatory actions.

Dental trauma: knowledge and attitudes of community health workers.

BACKGROUND: The international literature emphasizes the importance of evaluating the knowledge of different groups such as teachers, students, dentists, physicians, parents, and athletes regarding dental injuries. In Brazil, community health workers are professionals who can reach a wide variety of people and who have a marked influence on prevention and health promotion strategies. The objective of this study was to investigate the knowledge and attitudes of community health workers regarding dental trauma. METHODS: A questionnaire consisting of 19 questions divided into 3 parts was applied: demographic characteristics, knowledge, and attitudes. Data from 206 respondents were analyzed using descriptive statistics and logistic regression models. RESULTS: Approximately 28% of the participants reported to have been called to assist individuals with dental trauma. Only 42 subjects had received education on dental injuries, with 34 of them being instructed by a dentist. In cases of tooth avulsion, only 1.9% of the health workers reported that they would search for the tooth and reimplant it. The most frequently indicated storage media for avulsed teeth were nonphysiological media (69.42%). CONCLUSIONS: The educational level of the community health workers somehow influenced their knowledge (P < 0.001) and attitude (P = 0.016) regarding dental injuries. Educational programs for this group are needed to improve the management of traumatic dental injuries.

A clinicoradiographic and pathological study of pericoronal follicles associated to mandibular third molars.

BACKGROUND: Third molar surgery is considered the most frequently performed procedure in oral surgery. Although there are some indications for the removal of this tooth, such as the possibility of cystic degeneration or a tumor of the adjacent pericoronal follicle, there is no consensus in the literature about their prophylactic removal. OBJECTIVES: The aims of this study were to investigate the pathological alterations related to mandibular third molar dental follicles and to perform a narrative literature review. METHODS: A prospective clinical, radiographic, and histopathologic study was conducted with pericoronal follicles of third molars. After histopathologic evaluation and establishment of diagnosis, 2 groups were defined: G1 (pericoronal tissues with pathological alterations based on histopathologic analysis) and G2 (pericoronal tissues without pathological alterations based on histopathologic analysis). In addition, a systematic review of the literature was performed. RESULTS: One hundred thirteen specimens were analyzed. G1 was the most prevalent (P = 0.0004). Lesions were found in patients between 20 and 25 years of age (P < 0.004). The most prevalent histological diagnosis was the paradental cyst (47.7%; P < 0.0001). The narrative literature review showed that the majority of cases were mainly dentigerous cysts (P < 0.05). CONCLUSIONS: The mandibular third molars in young adults showed a direct relationship with age and a statistical propensity for the development of these cystic alterations, notably paradental cysts.

Beyond the mouth: Uncovering non-secretory multiple myeloma through oral symptoms.

Non-secretory multiple myeloma (NSMM) is a rare cancer of plasma cells characterized by the absence of detectable monoclonal M protein in the blood or urine. A 57-year-old woman presented with mandibular pain but without intraoral swelling. Imaging studies revealed multiple osteolytic lesions in her mandible and pronounced root resorption of the left mandibular second molar. Biopsy results showed atypical plasmacytoid cells positive for anti-kappa, CD138, MUM1, and CD79a antibodies, but negative for anti-lambda and CD20. These results were indicative of a malignant plasma cell neoplasm. No abnormalities were revealed by free light chain assay or by serum or urine protein electrophoresis, leading to a diagnosis of NSMM. The patient began chemotherapy in conjunction with bisphosphonate therapy and achieved remission following treatment. This case underscores the critical role of dentists in the early detection and prevention of NSMM complications, as the disease can initially present in the oral cavity.

Chenopodium Ambrosioides Linn Mitigates Bone Loss in Rats with Periodontitis.

Statement of the Problem: Periodontitis is an inflammatory disease that causes bone loss. Some patients do not respond well to the classic treatment and need therapies that minimize bone loss, the main sequel of the disease. Chenopodium ambrosioides L. has stood out due to its anti-inflammatory and anti-oxidative activities. However, no study has yet investigated its effect on periodontitis. Purpose: This study aimed to evaluate the bone protective effect of Chenopodium ambrosioides L. (CAL) extract on ligature-induced periodontitis model in rats. Materials and Method: For this, a pre-clinical assay was performed, using male Wistar rats divided into 3 groups: Naive (N) (n=6), not submitted to any procedure; Saline (SAL) (n=6), submitted to ligature-induced periodontitis and receiving 2 ml/kg of 0.9% saline solution; and CAL extract, which was subdivided into 3 subgroups (n=6/subgroup) receiving the CAL at 3 (CAL3), 10 (CAL10) or 30 mg/kg (CAL30). All agents were given, by oral gavage, 30 min before periodontitis induction and daily until euthanasia (11th day). By then, maxillae were removed for macroscopic, histological, and histometric analyses. Kidneys, liver, and stomach were collected to evaluate the safety of CAL extract. High-performance liquid chromatography (HPLC) assay was used to investigate the flavonoid content in the extract. Results: Chenopodium ambrosioides L. extract at 30mg/kg showed a reduction by 58% in bone loss marked by an increase (+35%) in the number of osteoblasts and a reduction (-51%) on the number of osteoclasts (p< 0.05). No significant alteration in the liver, kidney, or stomach was seen. Rutin was the main flavonoid found. Conclusion: In summary, it was observed that Chenopodium ambrosioides L. extract has shown important anti-inflammatory and bone anabolic and anti-resorptive properties without causing toxicity in the main organs. Rutin, as the main flavonoid of the extract, seems to be responsible for the beneficial effect of this agent.

Ulcerated anterior maxillary swelling showing radiopaque bodies on cone beam computed tomography.

The calcifying epithelial odontogenic tumor (CEOT), also known as Pindborg tumor, is a rare benign tumor of epithelial origin of locally aggressive behavior, which represents less than 1% of all odontogenic tumors affecting the oral cavity. The lesion usually presents as a nonulcerated painless mass of slow growth, commonly affecting the posterior region of the mandible. Depending on the stages of development, CEOTs may present variable radiographic appearances. To date, a few number of cases affecting the anterior maxillary region have been published in the English-language literature. This article describes an interesting and rare case of an anterior ulcerated maxillary swelling diagnosed as a CEOT based on clinical, cone beam computed tomography and pathologic findings. Functional results were obtained with the surgical approach, and no recurrence of the lesion during a 2-year follow-up period was observed.

Tumor Budding and Poor Prognosis in Oral Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Tumor budding (TB) has been investigated in several types of solid tumors. In oral cancer, studies show its association with survival. However, for its implementation in routine histological analyses, results with a high certainty of evidence are needed. Therefore, the aim of this systematic review is to explore the association between tumor budding and overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) in oral cancer. METHODS: A search was performed in Embase, PubMed, Scopus, Livivo, Web of Science, and Google Scholar. We adopted the following inclusion criteria: studies that evaluate tumor budding in oral cancer, that investigate survival, and presenting cohort design. We excluded reviews and studies without hazard-ratio (HR) data. RESULTS: This systematic review included 22 studies and showed an association between TB and survival. High-grade TB is associated with a worse OS in univariate analysis (HR = 3.11; 95% CI: 2.06-4.69, p<0.01) and multivariate analysis (HR = 2.62; 95% CI: 1.64-4.20, p<0.01); with a poorer DSS in univariate (HR = 2.43; 95% CI: 1.94-3.03, p<0.01) and multivariate analysis (HR = 2.01; 95% CI: 1.43-2.83, p< 0.01); and with a worse DFS in univariate (HR = 1.94; 95% CI: 1.44-2.62, p<0.01) and multivariate analysis (HR = 2.15; 95% CI: 1.31-3.53, p< 0.01). Sensitivity analysis showed that the results are robust, and no significant publication bias was identified in univariate analysis for DFS (Egger's test: p = 0.94). The certainty of the evidence was graded as low or very low. CONCLUSION: Our findings indicate that TB is an independent prognostic factor of OS, DSS, and DFS in oral cancer. However, further studies are needed to increase the certainty of the evidence.

Milk kefir therapy improves the skeletal response to resistance exercise in rats submitted to glucocorticoid-induced osteoporosis.

Glucocorticoid-induced osteoporosis (GIO) has emerged as a challenge after long-term glucocorticoids (GCs) administration. Exercise has been an important non-pharmacological option, while medications modulate bone remodeling despite adverse effects. In this way, milk Kefir (MK) therapy stands out as a safe alternative to improve bone metabolism. Our study aimed to investigate the effect of MK associated to resistance exercise on bone loss in rats with GIO. For this, sixty male Wistar rats were divided into 2 groups: normal (N) and subjected to GIO, which was subdivided into 4 groups: control (C), milk kefir therapy (K), Exercise (Ex), and Exercise+K (ExK). GIO was induced by dexamethasone (7 mg/kg - i.m.; 1×/wk, 5 wk). MK was administered daily (1×/day; 0.7 ml/animal) and the climb exercise with load was performed 3×/wk; both for 16 wk. Femur was collected for assessment of bone microarchitecture, quality and metabolism. GIO markedly reduced trabecular bone volume density (BV/TV) (-35 %), trabecular thickness (Tb.Th) (-33 %), mineral content of femur (-26 %) as well as bone collagen content (-56 %). Bone strength and its biomechanical properties given by flexural strength (-81 %), fracture load (-80 %), and the number of osteocytes (-84 %) were lowered after GIO. GCs reduced osteoblast number and function while increased osteoclast number, altering bone remodeling (p < 0.05). On the other hand, ExK significantly improved bone microarchitecture and quality, marked by fractal dimension increase (+38 %), cortical volume (+34 %), BV/TV (+34 %), Tb.Th (+33 %), mineral content and collagen maturity, while reduced the space between trabecula (-34 %). The Ex and ExK increased the number of osteocytes (p < 0.05) and they were able to reverse the lower osteoblast number. Both treatments used alone significantly enhanced bone biomechanical properties, but the ExK showed a more significant improvement. ExK ameliorated bone strength and biomechanics (p < 0.05) and stimulated bone formation and modulated bone remodeling (p < 0.05). MK and exercise administered isolated or in association increased the percentage of collagen bone filling after GIO (p < 0.05), but only ExK improved collagen maturity. Our results showed that MK associated to resistance exercise enhanced bone microarchitecture, quality and metabolism, being therefore an interesting tool to improve skeletal response during GIO.

Sialolipoma of minor salivary glands.

Sialolipoma is a recently described histologic variant of lipoma and is characterized by well-demarcated proliferation of mature adipocytes with secondary entrapment of salivary gland elements. These tumors have been observed in both the major and minor salivary glands, with more than 20 cases being reported in the English literature. In general, the clinical presentation of sialolipomas of the minor salivary glands suggests a diagnostic hypothesis of salivary gland lesions, commonly neoplasms. In the major salivary glands, the clinical features suggest either a salivary gland neoplasm or a lipoma. Surgical excision is the treatment of choice for sialolipomas, with no reports of recurrence or malignant transformation. The present article reports 4 additional cases of sialolipoma, all of them affecting the minor salivary glands, and reviews the literature regarding clinicopathologic aspects, differential diagnosis, and therapeutic management of this recently recognized histologic variant of lipoma.

Maxillary cementoblastoma in a child.

Cementoblastoma is a rare benign tumor that almost always occurs in the premolar or molar region and more commonly in the mandible than in the maxilla. We present a unique incisor maxillary cementoblastoma in an 11-year-old child not previously described. To our knowledge, only 2 maxillary cases, both related to canine teeth, were described in the international literature. Thus, the aim of this article was to discuss the clinical presentation, diagnosis, and subsequent treatment of a patient with a cementoblastoma in the anterior maxillary region.

Anti-inflammatory and Hepatoprotective Effects of Quercetin in an Experimental Model of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation in the joints. Although methotrexate (MX) is the first-line treatment, side effects are common. This study aimed to investigate the effects of quercetin (QT) and/or MX on inflammation and systemic toxicity in a rat model of RA. Male Wistar rats were divided into control (C), RA, QT, MX, and QT + MX groups (n=6). The RA induction consisted of three intra-articular injections of methylated bovine serum albumin (1×/week) in the temporomandibular joint (TMJ). QT (25 mg/kg) and/or MX (0.75 mg) administration occurred by oral gavage daily. We performed mechanical hyperalgesia in TMJ, leukocyte recruitment in synovial fluid, histopathology, and immunohistochemistry (TNF-α, IL-17, and IL-10) in synovial membrane and toxicity parameters. The RA showed a reduction in the nociceptive threshold (p<0.001), increase in leukocyte recruitment in synovial fluid (p<0.001), intense inflammatory infiltrate (p<0.001), and intense immunoexpression of TNF-α, IL-17, and IL-10 in the synovial membrane (p<0.001) compared to C (p<0.001). QT and/or MX therapy reduced inflammatory parameters (p<0.001). However, downregulation of IL-10 was observed only in the groups that received MX (p<0.001). Leukocytosis was seen in RA (p<0.05), but QT and/or MX reversed it (p<0.05). MX was associated with pathological changes in the liver and higher levels of transaminases when compared to the other groups (p<0.05). QT co-administered with MX reversed this hepatotoxicity (p<0.05). There were no alterations in the kidney between the groups (p>0.05). QT has potential to support MX therapy, showing anti-inflammatory and hepatoprotective effects in this model.

Milk Kefir therapy reduces inflammation and alveolar bone loss on periodontitis in rats.

Periodontitis is a chronic inflammatory disease that affects the tooth-supporting tissues. This study evaluated the anti-inflammatory and antiresorptive effects of milk kefir (MK) on periodontitis in rats. Micro-Raman spectroscopy was performed on MK at different fermentation times to verify the presence of Lactobacillus kefiri. From these results, Wistar rats were divided into the following groups: C (Control); EP (experimental periodontitis); K1 (animals that received MK with one day of fermentation); K1+EP; K4 (animals without EP using MK with four days of fermentation) and K4+EP. MK was administered 28 days before EP induction and during the disease development period (11 days). On day 28, in the EP groups, periodontitis was induced. The animals were euthanized on day 39. The hemimaxillae were removed and the following parameters were evaluated: micro-Raman analysis of the presence of inflammation; histomorphometric analysis to quantify alveolar bone loss and immunohistochemistry for IL-6, TNF-α, IL-Iß and IL-10 in the periodontal ligament. Micro-Raman analysis showed that four days fermentation MK has a higher intensity spectrum of L. kefiri. Furthermore, the administration of this probiotic reduced the intensity of the inflammation spectrum when compared to one day fermentation MK. It was observed that the animals from the K4+EP group showed significant reduction of alveolar bone loss, as well as a lower IL-6, TNF-α and IL-Iß immunoexpression and a higher IL-10 immunoexpression, when compared to EP groups. We conclude that MK has anti-inflammatory and antiresorptive effects on periodontitis in rats and that these effects are fermentation time dependent.