Treatment of Medication-Related Osteonecrosis of the Jaws without Segmental Resections: A Case Series

BACKGROUND Medication-related osteonecrosis of the jaw (MRONJ) is a rare but serious reaction to anti-resorptive drugs (ARDs) in patients treated for osteoporosis and conditions related to cancer. Treatment for MRONJ consists of the use of non-operative therapies according to the evolution of the disease, which consist of the use of antimicrobial mouthwashes, systemic antibiotics, and operative therapies, such as debridement of necrotic bone, marginal or segmental resection, and bone reconstruction of the jaws in more advanced stages of the disease. CASE REPORT This is a case series of 11 female patients treated for MRONJ, with a mean age of 76.5 years. Patients with malignant diseases of the jaws or those undergoing head and neck radiotherapy were excluded. Nine patients were medicated for osteoporosis with oral bisphosphonates and denosumab, and 2 patients used zoledronate to treat metastatic breast cancer. MRONJ prevailed in the mandible, most patients were classified as stage 2, and the most frequent triggers were tooth extraction and prosthetic trauma. All patients initially underwent non-operative therapies and were operated according to MRONJ stage, but none required segmental resection. Adjuvant treatments were used in 5 patients, and mean treatment and follow-up periods were 5 and 18.3 months, respectively. There was complete resolution of disease in all patients, with only 1 relapse. CONCLUSIONS This case series suggests that it is possible to treat MRONJ with conservative therapies in the early stages of the disease and minimally invasive surgeries in more advanced stages of the disease, thus avoiding segmental jaw resections.

A Case Report of Oral Bisphosphonate Treatment for Osteoporosis Leading to Atypical Femoral Fracture and Pathologic Mandibular Fracture

BACKGROUND Bisphosphonates inhibit bone resorption in patients with postmenopausal osteoporosis and reduce osteoporotic fracture incidence. Medication-related osteonecrosis of the jaws (MRONJ) and atypical femoral fractures (AFF) are both rare but serious adverse effects of anti-resorptive drugs (ARD) such as bisphosphonates. The most advanced form of MRONJ is termed stage 3 and can lead to severe local sequelae like pathologic mandibular fractures (PMF). This study reports a case of MRONJ-related PMF and AFF with osteomyelitis secondary to bisphosphonate treatment for osteoporosis. CASE REPORT A 63-year-old white woman was diagnosed with PMF related to MRONJ stage 3 during treatment of an AFF with osteomyelitis. She had been treated for postmenopausal osteoporosis with 70 mg of alendronate weekly for 2 years. The PMF was treated by stable internal fixation combined with debridement and sequestrectomy, but further debridement was required and 2 mandibular implants were then removed. Postoperative recovery was uneventful and the mandibular infection was controlled after the second surgery. Three weeks later, she was discharged from the hospital, instructed to discontinue the use of alendronate, and referred for 30 sessions of hyperbaric oxygen therapy. At the 3-year follow-up, the PMF was completely healed without signs of mandibular infection or bone exposure. CONCLUSIONS This report raises awareness of both MRONJ and AFF as possible adverse effects of short-term bisphosphonate therapy for postmenopausal osteoporosis, and highlights the importance of dental and orthopedic follow-ups. It is crucial to emphasize the need for early diagnosis and treatment to prevent MRONJ progression to PMF.

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.

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.

Effect of adrenaline and noradrenaline on biofilm formation and virulence factors of Streptococcus mutans UA159

OBJECTIVES

To evaluate in vitro the effects of adrenaline and noradrenaline on the biofilm formation on orthodontic brackets, acid production and expression of virulence genes of Streptococcus mutans UA159 (S. mutans).

DESIGN

S. mutans UA159 biofilm was formed on orthodontic brackets under exposure to adrenaline (100 μM), noradrenaline (50 μM) or PBS solution (control group) in triptone-yeast extract with 1 % sucrose. After 24 h, biofilm formation was quantified through Colony Forming Units / mL (CFU/mL) and RNA was extracted to perform gene expression analysis through real-time reverse transcriptase-PCR (RT-qPCR). Evaluation of acid production was carried out on planktonic cultures for 6 h. One-way ANOVA followed by Tukey's test was carried to determine statistical difference. The level of significance was set at 5 %.

RESULTS

Catecholamines stimulated biofilm formation of S. mutans in orthodontic brackets (p < 0,05) but did not interfere with acid production (pH reduction) or the expression of the tested genes related to biofilm formation (gtfB, gtfC, gbpA, gbpB, gbpC, gbpD and brpA), aciduric (relA) and acidogenic properties (ldh).

CONCLUSIONS

The present study was the first to demonstrate that catecholamines can stimulate S. mutans UA159 biofilm formation. These findings can contribute to clarify the role of stress on bacterial metabolism and contribute to the understanding of a possible role on caries development, mainly in orthodontic patients.

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.

Caloric restriction prevents alveolar bone loss in the experimental periodontitis in obese rats

AIMS

It has been shown that periodontitis, can be modified by systemic changes, including behavioral factors, such as diet. Caloric restriction is one of the dietary therapeutic strategies indicated for obesity. It is associated with several benefits, among them, modulation of the inflammatory response. The aim of this study was to verify whether caloric restriction in obese rats changes the progression of experimental ligature-induced periodontitis.

MATERIALS AND METHODS

Forty-eight Wistar rats were used for 24 weeks and initially fed with cafeteria diet during 12 weeks. The animals were divided into four groups according to the caloric restriction and experimental periodontitis. The cotton thread was placed around the mandibular first molars, for 15 days, before the end of the experiment. Rats submitted to caloric restriction received, from the 13th week of the experimental protocol, 70% of the food intake compared to the ad libitum animals of other study of the our research group. Alveolar bone loss was assessed using macroscopic morphometric analysis. Analyzes of clinical periodontal measures, biometrics, serum biomarkers and biochemical parameters were performed.

KEY FINDINGS

Caloric restriction decreased the alveolar bone loss in the periodontitis group when compared to the group that received a cafeteria diet with periodontitis. Moreover, the results demonstrate the improvement in the glycemic profile, without prejudice to bone tissue biomarkers.

SIGNIFICANCE

Based on the results, caloric restriction reduces the progression of alveolar bone loss in rats with experimental periodontitis, in addition to presenting benefits in biometric data, decreasing both glycemic profile and clinical periodontal measures.

Cervical spine range of motion, posture and electromyographic activity of masticatory muscles in temporomandibular disorders

Abstract Introduction: Temporomandibular joint disorders (TMD or TMJD) involve clinical problems and symptoms affecting the temporomandibular joint (TMJ) and associated structures. The temporomandibular joints are anatomically connected to the cervical region, where cervical spine movements occur simultaneously to masticatory muscle activation and jaw movements. Objective: Our study sought to assess the relationship between the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), surface electromyography (sEMG) of the masticatory muscles, posture and cervical flexibility in women with TMD. Method: Fifty women with an average age of 27.0 ± 6.37 years, diagnosed with TMD according to RDC/TMD, were assessed for craniocervical posture, cervical flexibility and sEMG of the masticatory muscles. Results: There were no differences in jaw function limitations, depression, pain level and its interference in work ability and daily activities, posture and sEMG between TMD diagnoses or between muscle classification (p > 0.05). Depression scores were higher among participants with biarticular dysfunction (p = 0.023). The group with bruxism exhibited a higher pain level at assessment (p = 0.001) and a greater reduction in work ability (p = 0.039). Subjects with muscular and mixed TMD showed less cervical rotation to the right when compared with those with articular TMD. Conclusion: There was no difference in posture or sEMG values for TMD diagnoses, joint and muscle dysfunctions and the presence of bruxism. Muscle dysfunction is associated with reduced cervical rotation to the right. Jaw function limitations did not interfere in posture or sEMG and depression was associated with pain.

Agreement, correlation, and kinetics of the alveolar bone-loss measurement methodologies in a ligature-induced periodontitis animal model

Periodontal research involves the use of animal models to better understand the biological processes of periodontal diseases and the potential of new or existing therapies. Currently, ligature-induced periodontitis in rats is the main model used in periodontal research, in this model, alveolar bone loss (ABL) is the main parameter evaluated by radiographic, morphometric, and histological techniques. Interestingly, although these methodologies are widely used, it is not totally clarified neither the kinetics of ABL over the induction time nor the agreement degree (repeatability and reproducibility) of these techniques. Objective: To characterize ABL kinetics at 0, 3, 7, 15, 30, and 60 days after ABL induction by ligature and to evaluate the intra- (repeatability) and inter-examiner (reproducibility) agreement and the correlation among the radiographic, morphometric, and histological methodologies. Material and Methods: 60 male Wistar rats with induced ABL were randomly divided into 6 experimental groups (n = 10 animals/group). After 0, 3, 7, 15, 30, and 60 days, the animals were euthanized and their hemimandibles were removed for ABL determination using radiographic, morphometric and histological techniques. Results: Radiographic and morphometric/linear techniques allowed the detection of statistically significant ABL on the third day, while histological and morphometric/area techniques could only detect ABL after the seventh day (ANOVA/Tukey, p<0.05). After the fifteenth day, except for histological analysis, the ABL was stabilized. Concerning the agreement of the methodologies, Bland Altman's test (intra and inter-examiner evaluations) showed no difference among the measurements (p>0.05). In addition, high correlations (Pearson's test, r2>0.9, p<0.05) were observed. Conclusion: The results indicated that the minimum time for ABL induction could vary from 3 to 7 days, according to the chosen analysis methodology. Agreement and correlation data support the comparison of results between studies with same induction time.

Influence of Adrenergic Neuromodulation during Induction of Periodontitis in Rats

The action of the sympathetic nervous system in the control of bone remodeling and immunoinflammatory responses is the basis of the hypothesis that its modulation can influence the progress of periodontal disease. The aim of this study was to analyze the effects of the blockade and of the activation of β-adrenergic receptors in periodontal disease in rats. Thirty-two rats were divided into four groups: 1) animals with induced periodontitis that received propranolol (a non-selective β-adrenergic antagonist) 0.1 mg/kg (PRO); 2) animals with induced periodontitis that received isoproterenol (a non- selective β-adrenergic agonist) 0.75 mg/kg (ISO); 3) animals with induced periodontitis and without drug treatment (L); and 4) animals without induced periodontitis and without drug treatment - control (C). After 14 days of treatment, the rats were euthanized. Right hemi-mandibles were removed and lingual alveolar bone loss measurements were made under a stereomicroscope. Left hemi-mandibles were decalcified and submitted to routine histological preparation for the evaluation of alveolar bone loss in furcation regions, amount of gingival collagen, and immunohistochemistry for receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) ratio. Animals treated with isoproterenol had significantly more lingual alveolar bone loss than others. The percentage of collagen in gingiva was greater in the propranolol group than in the isoproterenol group. No statistical differences were found among groups with periodontal disease in any other evaluations. The activation of β-adrenergic receptors increased the lingual alveolar bone loss; however, in the model used, the use of β-adrenergic antagonist drugs was not able to modulate the host response significantly. Activation and inhibition of β-receptors have antagonistic actions in collagen degradation in animals with periodontal disease.

Effects of Cinnamoyloxy-mammeisin from Geopropolis on Osteoclast Differentiation and Porphyromonas gingivalis-Induced Periodontitis

Bone-loss-related diseases such as rheumatoid arthritis, osteomyelitis, osteoporosis, and periodontitis are associated with high rates of morbidity worldwide. These disorders are characterized by an imbalance between the formation and activity of osteoblasts and osteoclasts, leading to bone loss. In this context, we evaluated the effect of cinnamoyloxy-mammeisin (CNM), an anti-inflammatory coumarin found in Melipona scutellaris geopropolis, on key targets related to bone remodeling. In the present study we investigated the in vitro effects of CNM on osteoclast differentiation and M-CSF+RANKL-induced osteoclastogenic marker expression. Additionally, the interference of CNM treatment on osteoclast activity was evaluated by zymography and resorption area. Finally, we assessed the capacity of the compound to mitigate alveolar bone loss in vivo in experimental murine periodontitis induced by Porphyromonas gingivalis. We observed that treatment with CNM impaired osteoclast differentiation, as evidenced by a reduced number of tartrate-resistant acid-phosphatase-positive multinucleated cells (TRAP+) as well as the expression of osteoclastogenic markers upon M-CSF+RANKL-induced stimulation. Similarly, we observed reduced gelatinolytic and resorption capacity in M-CSF+RANKL-induced cells in vitro. Lastly, CNM attenuated alveolar bone loss in an experimental murine periodontitis model. These findings indicate that CNM may be considered a promising treatment for bone loss diseases.

Biología de la ciclooxigenasa en la función renal – Revisión de la literatura

La ciclooxigenasa existe en dos isoformas principales: COX-1 y COX-2, estas se encuentran presentes en el sistema renal como parte de su homeostasis. Sin embargo, en algunas situaciones clínicas, las dos enzimas pueden desempeñar un papel en el mantenimiento de la integridad de este órgano, y en otras pueden estar asociadas a la evolución de daños y lesiones en los tejidos. En este sentido, el conocimiento de la verdadera función biológica de las isoformas de la COX permite una mejor comprensión de la fisiología y patología del riñón, así como una mejor comprensión de las consecuencias de su inhibición por el uso de medicamentos. El objetivo de esta revisión es estudiar la función biológica de la enzima COX en el sistema renal en diferentes situaciones clínicas.

Frequency of periodontal pathogens and Helicobacter pylori in the mouths and stomachs of obese individuals submitted to bariatric surgery: a cross-sectional study

OBJECTIVES

This cross-sectional study compared the frequency of oral periodontopathogens and H. pylori in the mouths and stomachs of obese individuals with or without periodontitis submitted to bariatric surgery.

MATERIAL AND METHODS

One hundred and fifty-four men and women aged 18-65 were conveniently distributed into four groups. Two groups were composed of individuals who underwent bariatric surgery with (BP) (n=40) and without (BNP) (n=39) periodontitis and two obese control groups with (CP) (n=35) and without (CNP) (n=40) periodontitis. The oral pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Parvimonas micra, Treponema denticola, Tannerella forsythia, Campylobacter rectus, and Helicobacter pylori were detected by a polymerase chain reaction technique using saliva, tongue and stomach biopsy samples.

RESULTS

Statistical analysis demonstrated that periodontopathogens were highly frequent in the mouth (up to 91.4%). In the bariatric surgically treated group, orally, P. gingivalis, T. denticola and T. forsythia were more frequent in periodontitis, while C. rectus was more frequent in non-periodontitis subjects. Stomach biopsies also revealed the high frequency of five oral species in both candidates for bariatric surgery (91.6%) and the bariatric (83.3%) groups. H. pylori was frequently detected in the mouth (50.0%) and stomach (83.3%). In the stomach, oral species and H. pylori appeared in lower frequency in the bariatric group.

CONCLUSIONS

Obese individuals showed high frequencies of periodontopathogens and H. pylori in their mouths and stomachs. Bariatric surgery showed an inverse microbial effect on oral and stomach environments by revealing higher oral and lower stomach bacterial frequencies.

Gastric and renal effects of COX-2 selective and non-selective NSAIDs in rats receiving low-dose aspirin therapy

The consumption of low-dose aspirin (LDA) to prevent cardiovascular disease continues to increase worldwide. Consequently, the number of chronic LDA users seeking dental procedures that require complementary acute anti-inflammatory medication has also grown. Considering the lack of literature evaluating this interaction, we analyzed the gastric and renal effects caused by a selective COX-2 inhibitor (etoricoxib) and a non-selective COX-2 inhibitor (ibuprofen) nonsteroidal anti-inflammatory drug (NSAID) in rats receiving chronic LDA therapy. Male Wistar rats were divided into six experimental groups (carboxymethylcellulose (CMC) - vehicle; LDA; LDA + ibuprofen; ibuprofen; LDA + etoricoxib; and etoricoxib) and submitted to long-term LDA therapy with a subsequent NSAID administration for three days by gavage. After the experimental period, we analyzed gastric and renal tissues and quantified serum creatinine levels. The concomitant use of LDA with either NSAID induced the highest levels of gastric damage when compared to the CMC group (F = 20.26, p < 0.05). Treatment with either LDA or etoricoxib alone was not associated with gastric damage. No significant damage was observed on kidney morphology and function (F = 0.5418, p > 0.05). These results suggest that even the acute use of an NSAID (regardless of COX-2 selectivity) can induce gastric damage when combined with the long-term use of low-dose aspirin in an animal model. Additional studies, including clinical assessments, are thus needed to clarify this interaction, and clinicians should be careful of prescribing NSAIDs to patients using LDA.

Anti-Inflammatory, Anti-Osteoclastogenic and Antioxidant Effects of Malva sylvestris Extract and Fractions: In Vitro and In Vivo Studies

Given their medical importance, natural products represent a tremendous source of drug discovery. The aim of this study was to investigate Malva sylvestris L. extract and fractions and their pharmacological activities followed by chemical identification. The aqueous fraction (AF) was identified as the bioactive fraction in the in vitro and in vivo assays. The AF controlled the neutrophil migration to the peritoneal cavity by 66%, inhibited the antiedematogenic activity by 58.8%, and controlled IL-1β cytokine expression by 54%. The in vitro viability tests showed a concentration-dependent effect, where the MSE and fractions at concentrations under 10 μg/mL were non-toxic to cells. Transcriptional factors of carbonic anhydrase II (CAII), cathepsin K (Ctsk) and tartrate-resistant acid phosphatase (TRAP) were analyzed by qPCR in RAW 264.7 cell lines. The gene expression analysis showed that the AF was the only treatment that could downregulate all the study genes: CAII, Ctsk and TRAP (p<0.05). TRAP staining was used to evaluate osteoclast formation. AF treatments reduced the number of osteoclastogenesis 2.6-fold compared to the vehicle control group. Matrix metalloproteinase 9 (MMP-9) activity decreased 75% with the AF treatment. Moreover, the bioactive fraction had the ability to regulate the oxidation pathway in the ABTS (2,2-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) assay with an activity equivalent to 1.30 μmol Trolox/g and DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals 1.01 g/L. Positive ion ESI-mass spectrometry for molecular ions at m/z 611 and 633 confirmed rutin as the major compound in the AF. The AF of M. sylvestris presented anti-inflammatory, controlled osteoclastogenic mechanisms and antioxidant abilities in different in vitro and in vivo methods. In addition, we suggest that given its multi-target activity the bioactive fraction may be a good candidate in the therapy of chronic inflammatory diseases.

Inactivation of the spxA1 or spxA2 gene of Streptococcus mutans decreases virulence in the rat caries model

In oral biofilms, the major environmental challenges encountered by Streptococcus mutans are acid and oxidative stresses. Previously, we showed that the transcriptional regulators SpxA1 and SpxA2 are involved in general stress survival of S. mutans with SpxA1 playing a primary role in activation of antioxidant and detoxification strategies whereas SpxA2 serves as a back up activator of oxidative stress genes. We have also found that spxA1 mutant strains (∆spxA1 and ∆spxA1∆spxA2) are outcompeted by peroxigenic oral streptococci in vitro and have impaired abilities to colonize the teeth of rats fed a highly cariogenic diet. Here, we show that the Spx proteins can also exert regulatory roles in the expression of additional virulence attributes of S. mutans. Competence activation is significantly impaired in Δspx strains and the production of mutacin IV and V is virtually abolished in ΔspxA1 strains. Unexpectedly, the ∆spxA2 strain showed increased production of glucans from sucrose, without affecting the total amount of bacteria within biofilms when compared with the parent strain. By using the rat caries model, we showed that the capacity of the ΔspxA1 and ΔspxA2 strains to cause caries on smooth tooth surfaces is significantly impaired. The ∆spxA2 strain also formed fewer lesions on sulcal surfaces. This report reveals that global regulation via Spx contributes to the cariogenic potential of S. mutans and highlights that animal models are essential in the characterization of bacterial traits implicated in virulence.

The effect of an inhibitor of gut serotonin (LP533401) during the induction of periodontal disease

BACKGROUND AND OBJECTIVE

LP533401 is an inhibitor of tryptophan hydroxylase 1, which regulates serotonin production in the gut. Previous work indicates that LP533401 has an anabolic effect in bone. Thus, we hypothesized that inhibition of gut serotonin production may modulate the host response in periodontal disease. In this study, we aimed to analyze the effects of LP533401 in a rat periodontitis model to evaluate the role of gut serotonin in periodontitis pathophysiology.

MATERIAL AND METHODS

Twenty-four rats were divided into three groups: treated group (T: ligature-induced periodontal disease and LP533401, 25 mg/kg/d) by gavage; ligature group (L: ligature-induced periodontal disease only); and control group (C: without ligature-induced periodontal disease). After 28 d, radiographic alveolar bone support was measured on digital radiographs, and alveolar bone volume fraction, tissue mineral density and trabeculae characteristics were quantified by microcomputed tomography in the right hemi-mandible. Left hemi-mandibles were decalcified and alveolar bone loss, attachment loss and area of collagen in the gingiva were histologically analyzed.

RESULTS

Significant difference between the L and C groups was found, confirming that periodontal disease was induced. We observed no difference between the T and L groups regarding alveolar bone destruction and area of collagen.

CONCLUSION

LP533401 (25 mg/kg/d) for 28 d does not prevent bone loss and does not modulate host response in a rat model of induced periodontal disease.

Dependence of cytokine levels on the sex of experimental animals: a pilot study on the effect of oestrogen in the temporomandibular joint synovial tissues

The aim of this study was to evaluate the effects of 17β-oestradiol (E2) on cartilage thickness and cytokine levels in the temporomandibular joint (TMJ). Thirty rats (15 female, 15 male) were orchidectomized (ORX), ovariectomized (OVX), or sham-operated. After 21 days, animals were assigned to six groups: (1) sham-ORX; (2) ORX; (3) ORX+E2; (4) sham-OVX; (5) OVX; and (6) OVX+E2. Treatments were administered daily for 21 days. The thickness of cartilage layers (fibrous, proliferative, maturation, and hypertrophic) and cytokine levels (interleukins IL-1α, IL-1β, IL-6, and tumour necrosis factor alpha (TNF-α)) were measured by histomorphometry and ELISA, respectively. Kruskal-Wallis/Dunn's tests were used (alpha=5%). Sham-ORX showed thicker layers than ORX+E2, but not thicker than ORX. All layers, except the hypertrophic layer, were thicker in sham-OVX than OVX or OVX+E2. Although IL-1β levels were higher in castrated animals, E2 did not affect the level of this cytokine. IL-1α levels were higher in both ORX (P=0.0010) and ORX+E2 (P=0.0053) than in sham-ORX. However, E2 decreased IL-1α levels in OVX (P=0.0129). When compared to sham-ORX/OVX, IL-6 levels were not affected by E2 in males but were reduced in OVX (P=0.0079) and increased in OVX+E2 (P=0.0434). Levels of TNF-α were reduced by E2 in both ORX+E2 and OVX+E2. E2 treatment caused gender- and layer-dependent changes in the cartilage. Castration increased all cytokine levels, except for IL-6, without respect to gender.

Do elderly edentulous patients with a history of periodontitis harbor periodontal pathogens?

OBJECTIVES

The presence of periodontal pathogens in the oral cavity may impact implant survival. Therefore, this study aimed to determine the prevalence of Campylobacter rectus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Tannerella forsythia, Treponema denticola, Eikenella corrodens, and Parvimonas micra in a specific elderly population with a history of periodontitis who have never worn dentures.

MATERIAL AND METHODS

Thirty dentate subjects (mean age 61.7 +/- 7.05 years) and 30 edentulous subjects (mean age 65.8 +/- 8.05 years) were included in this cross-sectional study. Microbiological samples of cheek mucosa and the dorsum of the tongue were taken from all subjects. In addition, sulcus samples were taken from the dentate group. All samples were analysed using a bacterial DNA-specific polymerase chain reaction.

RESULTS

All the pathogens studied were detected in dentate and edentulous subjects. When cheek and tongue samples were combined, C. rectus, A. actinomycetemcomitans and E. corrodens presented with a similar prevalence in both groups, whereas the other species were more prevalent specifically in the dentate group (P<0.05). In dentate subjects, P. intermedia and T. denticola were present in higher frequencies in the cheek mucosa (26.67% and 66.67%, respectively), whereas P. gingivalis and T. forsythia were more prevalent in the tongue samples (26.67% and 56.67%, respectively).

CONCLUSIONS

Periodontal pathogens may persist in the oral cavity of edentulous subjects who have had periodontal disease, even 1 year after the extraction of all teeth and in the absence of other hard surfaces in the mouth.

Prevalence of periodontopathogens in a black Brazilian secluded community matched with a black urban population

OBJECTIVE

To evaluate the prevalence of periodontopathogens according to periodontal profile in a black Brazilian secluded community matched with an urban black population.

PARTICIPANTS

A total of 84 subjects were selected, 42 (mean age 25.7 sd 18.0 years) from a secluded community called Santo Antonio do Guapore (SAG) and 42 (mean age 25.4 sd 18.1 years) from an urban area of Sao Paulo State (SPT).

METHODS

Participants received clinical examinations as follows: periodontal pocket depth; clinical attachment loss; plaque and gingival indexes. After examination, the secluded population was classified as periodontal health (13), gingivitis (15) or periodontitis (14). Then, 182 urban volunteers were screened and 42 subjects were selected matched for the variables: periodontal diagnosis, age (+/- 2 years) and gender. Samples were taken for microbial analysis. Genomic DNA for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, Tannerella forsythia and Prevotella intermedia was provided by polymerase chain reaction.

RESULTS

Except for C. rectus, all pathogens were present in both groups with no statistically significant difference. In particular, C. rectus was more prevalent only in gingivitis subjects from the SPT group (p<0.05). A high frequency of periodontopathogens was related to the severity of periodontal disease.

CONCLUSION

In general, the prevalence of the examined periodontopathogens in this study did not differ between a secluded black Brazilian population and an urban black population.

Occurrence of Aggregatibacter actinomycetemcomitans in Brazilians with chronic periodontitis

Studies have suggested that A. actinomycetemcomitans is involved in the aetiology of aggressive periodontitis as well as in chronic periodontitis. This study was aimed at elucidating the occurrence of A. actinomycetemcomitans in a Brazilian population with chronic periodontitis. A total of 555 (mean age 33.04 +/- 12.45) individuals, living in two large areas of the São Paulo State, namely "Baixada Santista" and "Vale do Paraíba", and diagnosed with mild [180 (mean age 29.59 +/- 10.94)], moderate [241 (mean age 31.18 +/- 11.45)] or severe [134 (mean age 33.04 +/- 12.45)] chronic periodontitis were enrolled in this survey. Clinical exams including measurements of Probing Depth, Clinical Attachment Loss, Plaque and Gingival indices and subgingival microbiological assessments were performed at all population. The genomic DNA of A. actinomycetemcomitans was identified by Polymerase Chain Reaction from periodontal pocket samples. The occurrence of A. actinomycetemcomitans among chronic periodontitis subjects as well as its association with age and gender were statistically analysed using the Chi-square and Odds Ratio tests. The significance of differences was established at 5% (p < 0.05). A. actinomycetemcomitans was detected in 102 (18.37%) individuals: 29 (16.11%) mild; 42 (17.42%) moderate; and 31 (23.13%) severe chronic periodontitis with no statistical difference among groups. A higher occurrence of the searched bacterium was found both in the youngest group (p < 0.05) as well as in the female group (p < 0.05). This study elucidated that A. actinomycetemcomitans harbored subgingival pockets of our target group of chronic periodontitis subjects and that this bacterium seems to be inversely related to age, but related to the female gender.

Clinical status and detection of periodontopathogens and Streptococcus mutans in children with high levels of supragingival biofilm

Knowledge about the presence of some important oral pathogens is an important step in better identifying children at risk for periodontal and/or caries diseases in later life. The purpose of this study was to detect the presence of Streptococcus mutans (Sm), Aggregatibacter actinomycetemcomitans (Aa), Campylobacter rectus (Cr), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Tannerella forsythia (Tf) in gingival biofilm samples from 196 children, and to assess whether any of these pathogens are more associated with gingival inflammation extension and the Decayed/Missing/Filled teeth (DMFT/dmft) index. The subjects presented plaque index greater than 80% and were divided in 3 groups according to the bleeding index (BI): I) Low bleeding (< 30%), II) Medium bleeding (31 - 59%) and III) High bleeding (> 60%). The presence of each pathogen was determined by PCR. The prevalence of Sm was 71.9% and the mean dmft/DMFT was 6.68. The prevalence in low, medium and high bleeding groups was 43.5%, 34.5% and 46.7% for Aa; 43.5%, 37.9%, and 36.7% for Cr; 99.1%, 100%, and 96.7% for Pg; 56.5%, 56.9%, and 66.7% for Pi; and 58.3%, 60.3%, and 56.7% for Tf, respectively. Pg (99.0%) was the most prevalent periodontal pathogen detected followed by Tf (58.7%), Pi (58.2%), Aa (41.3%) and Cr (40.8%). Our study indicated that in this high plaque index population studied, a high prevalence of Sm and high mean DMFT were observed. In addition, the presence of Pi was associated with the presence of inflammation (P < 0.05) whereas Cr was associated with periodontal health (P < 0.05).

Psychological stress has no association with salivary levels of β-defensin 2 and β-defensin 3

BACKGROUND

Recent studies suggest that stress can predispose an individual to the development of periodontal disease, but the exact biological mechanism is unknown. Considering that psychological stress can down-regulate the production of β-defensins (antimicrobial peptides produced in the oral cavity), the aim of the present study was to evaluate the association between stress and salivary levels of β-defensin 2 (HBD-2) and β-defensin 3 (HBD-3).

METHODS

For this purpose, seventy five volunteers, classified as periodontally healthy, were submitted to a psychological evaluation using a validated questionnaire (Questionnaire of Lipp-ISS). Following analysis of the questionnaires, the subjects were divided in two groups (Group A: Absence of stress and Group B: Presence of stress). Unstimulated saliva samples were collected and the concentration of total protein was determined using the BCA method, and the concentrations of HBD-2 and HBD-3 were determined by ELISA.

RESULTS

The levels of total protein did not show a statistically significant difference between the groups. Analyses of HBD-2 and HBD-3 concentrations indicate that the stress condition was not associated with the levels of either peptide in saliva (P=0.3664 for HBD-2 and P=0.3608 for HBD-3).

CONCLUSION

In periodontally healthy subjects, HBD-2 and HBD-3 levels are not influenced by stress.

Effect of sodium diclofenac on the bioavailability of amoxicillin

The aim of this study was to evaluate the effect of sodium diclofenac on the bioavailability of amoxicillin. In this randomised, crossover study with a 1-week washout period, 20 volunteers received a 2g oral dose of amoxicillin (Amoxil) (Group 1) or a 2g oral dose of amoxicillin with 100 mg of sodium diclofenac (Voltaren) (Group 2). Blood samples were collected at 0, 0.25, 0.5, 1, 1.5, 2, 2.5, 4, 6, 8, 12 and 24h following drug administration. High-performance liquid chromatography with ultraviolet detection was used to quantify plasma amoxicillin concentrations. Bioassay (Micrococcus luteus ATCC 9341) was performed to verify the antimicrobial efficacy of amoxicillin in vitro. The pharmacokinetic parameters area under the plasma concentration-time curve (AUC), maximum plasma concentration observed during the 24-h study period (C(max)) and renal clearance (CL) were analysed by analysis of variance, and time at which C(max) occurred (T(max)) and volume of distribution (VD) were analysed by Wilcoxon test (P<0.05). For Group 1, the mean (+/- standard deviation) AUC(0-24), C(max) and T(max) values were 3391.8+/-1186.7 microg min/mL, 17.3+/-6.5 microg /mL and 121.5+/-20.6 min, respectively; and for Group 2, the values were 2918.4+/-1024.8 microg min/mL, 15.5+/-5.8 microg /mL and 136.5+/-30.0 min, respectively. Lower values of AUC and C(max) were observed for Group 2 (P<0.05). CL of amoxicillin increased (P< 0.05) by 18.5% in Group 2, suggesting that sodium diclofenac may interfere with amoxicillin renal excretion. In conclusion, sodium diclofenac can significantly reduce the bioavailability of amoxicillin.

Comparative bioavailability of clarithromycin formulations in healthy Brazilian volunteers

OBJECTIVE

To compare the bioavailability of clarithromycin 500 mg tablets (Merck S.A Industrias Quimicas, Sao Paulo, SP, Brazil, used as test formulation) and Klaricid (Abbott Laboratórios do Brasil Ltda, Sao Paulo, SP, Brazil, used as reference formulation) in 24 healthy volunteers.

MATERIAL AND METHODS

The study was conducted using an open, randomized, two-period crossover design with one-week interval between doses. Blood samples were collected at pre-dose, 0.33, 0.66, 1, 1.33, 1.66, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 20 and 24 hours after the administration. AUC was calculated by the trapezoidal rule extrapolation method. Cmax and tmax were compiled from the plasmatic concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC(0-inf), AUC(0-24 h), Cmax and untransformed tmax.

RESULTS

Intraindividual coefficient of variation (CV%) values were 14.25% and 12.62%, respectively for Cmax and AUC(0-24 h). The geometric mean values (+/- SD) for AUC(0-24 h) (microg x h/ml), AUC(0-inf) (microg x h/ml), and Cmax (microg/ml) for test medication were 18.56 (+/- 6.87), 18.8 (+/- 5.70) and 2.45 (+/- 0.88); the obtained values for reference medication were 18.29 (+/- 5.39), 19.10 (+/- 7.21) and 2.5 (+/- 0.69). 90% Cl for clarithromycin geometric mean of AUC(0-24 h), AUC(0-inf) and Cmax ratios (test/reference) were: 93.6-105.9%, 93.8-106.2% and 89- 103.2%. CCONCLUSION The test medication was considered bioequivalent to the reference medication based on the rate and extent of absorption.

Comparative bioavailability of 875 mg amoxicillin tablets in healthy human volunteers

OBJECTIVE

To compare the bioavailability of amoxicillin 875 mg tablets (EMS Sigma Pharma used as test formulation) and Amoxil BD 875 mg tablets (GlaxoSmithKline used as reference formulation) in 26 healthy volunteers.

MATERIAL AND METHODS

26 healthy volunteers (13 males and 13 females) received each formulation in an open, 2 x 2 crossover, randomized study with seven days of washout period between doses. Plasma samples were obtained over a 12-hour interval after administration. Plasmatic amoxicillin concentrations were obtained by combined reversed-phase liquid chromatography and mass spectrometry with positive ion electrospray ionization using the select ion monitoring method. AUC was calculated by the trapezoidal rule extrapolation method. Cmax and tmax were compiled from the plasmatic concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC0-inf, AUC0-12 h, Cmax and untransformed tmax.

RESULTS

The mean values (+/- SD) for AUC0-12 h (microg x h x ml(-1)), AUC0-inf (microg x h x ml(-1)), Cmax (microg x ml(-1)), t1/2 (h) and tmax (h), were, respectively: 55.42 (+/- 16.85), 55.42 (+/- 16.85), 18.59 (+/- 6.3), 1.49 (+/- 1.57) and 2.04 (+/- 0.75) concerning the test formulation, and 51.11 (+/- 18.9), 51.29 (+/- 19.12), 17.83 (+/- 5.86), 1.52 (+/- 1.31) and 2.02 (+/- 0.87) concerning the reference formulation. Confidence intervals (90%) of amoxicillin means of AUC0-12 h and Cmax ratios (test/reference) were: 0.961-1.149 and 0.914-1.142, respectively, agreeing with the bioequivalence criteria established by the Brazilian National Health Surveillance Agency.

CONCLUSION

Both formulations were bioequivalent based on both the rate and extent of absorption.