Oral commensal bacteria differentially modulate epithelial cell death.

OBJECTIVE: Epithelial cell death is an important innate mechanism at mucosal surfaces, which enables the elimination of pathogens and modulates immunoinflammatory responses. Based on the antimicrobial and anti-inflammatory properties of cell death, we hypothesized that oral epithelial cell (OECs) death is differentially modulated by oral bacteria. MATERIAL AND METHODS: We evaluated the effect of oral commensals Streptococcus gordonii (Sg), Streptococcus sanguinis (Ss), and Veillonella parvula (Vp), and pathogens Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), and Fusobacterium nucleatum (Fn) on OEC death. Apoptosis and necrosis were evaluated by flow cytometry using FITC Annexin-V and Propidium Iodide staining. Caspase-3/7 and caspase-1 activities were determined as markers of apoptosis and pyroptosis, respectively. IL-1ß and IL-8 protein levels were determined in supernatants by ELISA. RESULTS: Significant increases in apoptosis and necrosis were induced by Sg and Ss. Pg also induced apoptosis, although at a substantially lower level than the commensals. Vp, Tf, and Fn showed negligible effects on cell viability. These results were consistent with Sg, Ss, and Pg activating caspase-3/7. Only Ss significantly increased the levels of activated caspase-1, which correlated to IL-1ß over-expression. CONCLUSIONS: OEC death processes were differentially induced by oral commensal and pathogenic bacteria, with Sg and Ss being more pro-apoptotic and pro-pyroptotic than pathogenic bacteria. Oral commensal-induced cell death may be a physiological mechanism to manage the extent of bacterial colonization of the outer layers of mucosal epithelial surfaces. Dysbiosis-related reduction or elimination of pro-apoptotic oral bacterial species could contribute to the risk for persistent inflammation and tissue destruction.

PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity.

Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05) PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.

PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity

Abstract Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05) PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.

Periodontitis in marfan syndrome: a case report

A Síndrome de Marfan é uma doença autossômica dominante do tecido conjuntivo, caracterizada por alterações nos sistemas cardiovascular, esquelético e ocular, e que pode aumentar a suscetibilidade à doença periodontal. Esse relato de caso descreve dados periodontais clínicos, microbiológicos e imunológicos de um paciente de 28 anos, gênero masculino, com diagnóstico clínico de Síndrome de Marfan. Neste caso, as principais alterações estão nos sistemas esquelético e ocular. A principal alteração intraoral é a presença de palato profundo e prognatismo mandibular. No exame clínico periodontal, a média do nível clínico de inserção foi de 2,35 mm e índice de sangramento à sondagem de 30%. O tratamento periodontal foi executado em uma sessão de debridamento e orientação de higiene oral, sob antibioticoterapia profilática. Na reavaliação, o paciente apresentou melhora nos parâmetros clínicos periodontais. O relato de caso apresenta um paciente com alterações leves, que afetam a saúde bucal. Em casos de Síndrome de Marfan, a manutenção da saúde periodontal é essencial para um bom prognóstico da saúde bucal.(AU)

Marfan syndrome is an autossomal dominant disorder of connective tissue characterized by alteration in cardiovascular, skeletal and ocular system, and may increase the susceptibility of periodontal disease. This case report describes the clinical, microbiological and immunological periodontal findings in a 28 year old male patient with a clinical diagnosis of Marfan syndrome. The major alterations of the case were in ocular and skeletal system. The major oral alterations were the high arched and narrow palate, and mandibular prognathism. At periodontal examination, an average clinical attachment level loss of 2.35 mm and 30% of bleeding on probing were found. The periodontal treatment was performed, in one session of periodontal debridement with prophylactic antibiotic premedication and oral hygiene instructions. At the revaluation, the patient showed improved clinical parameters. This case report presented a patient with mild features of a genetic disorder which affects oral health. The maintenance of periodontal health in Marfan syndrome cases is essential for a favorable prognosis of oral health.(AU)

Influence of parstatin on experimental periodontal disease and repair in rats.

BACKGROUND: Parstatin is a 41-amino acid peptide, formed by proteolytic cleavage on activation of the protease activated receptor-1, with antiangiogenic properties. The purpose of this study is to evaluate the influence of synthetic parstatin on experimental periodontal disease and repair in rats. METHODS: Ligature-induced periodontitis was established in rats and the influence of parstatin administration was assessed after 8 and 15 days for periodontal disease and 24 hours and 8 days after repair after ligature removal. RESULTS: Parstatin administration significantly inhibited gingival myeloperoxidase activity, interleukin (IL)-1ß, tumor necrosis factor-α, and IL-6 levels and led to suppression of macrophages and collagen degradation. At periodontal tissues under repair, parstatin increased the gingival levels of endostatin and decreased vascular endothelial growth factor expression and blood vessel number but did not influence histologic healing. In addition, the tomographic linear bone loss was significantly reduced at 15 days of periodontitis when the rats were treated with parstatin compared to their respective phosphate-buffered saline-treated controls. CONCLUSIONS: Parstatin suppresses the periodontal tissue breakdown followed by experimental periodontitis in rats and did not impair periodontal tissue repair, despite its antiangiogenic effect. Parstatin may represent a novel approach to modulate host response in chronic periodontal disease.

Efeito da terapia periodontal sobre a expressão do receptor ativado por protease do tipo 2 (PAR2) em pacientes com periodontite crônica / Evaluation of the protease activated receptor 2 (PAR2) expression in chronic periodontitis patients, before and after non-surgical periodontal treatment

O receptor ativado por protease do tipo 2 (PAR2) está envolvido na patogênese de doenças inflamatórias crônicas, incluindo a periodontite. O PAR2 pode ser ativado pela gingipaína, produzida pela Porphyromonas gingivalis (P. gingivalis) e proteinase 3 (P3) do neutrófilo. A ativação do PAR2 desempenha um papel relevante nos processos inflamatórios ao induzir a liberação de importantes mediadores pró-inflamatórios associados à destruição periodontal. No presente estudo, o efeito do tratamento periodontal não-cirúrgico na expressão do PAR2 por células do fluido gengival, bem como a sua associação com os níveis de mediadores pró-inflamatórios e proteases ativadoras foram investigados em pacientes com periodontite. Além disso, avaliou-se in vitro o envolvimento da via de sinalização MAPK-p38 na ativação do PAR2 e a influência deste na produção de superóxido (O2-) e na capacidade de fagocitose em neutrófilos do sangue periférico humano infectados pela P. gingivalis. Um aumento significativo (P < 0,05) da expressão do RNAm e proteica do PAR2 por células do fluido gengival foi positivamente associado aos parâmetros clínicos inflamatórios e aos níveis de interleucina (IL)-6, IL-8, fator de necrose tumoral-, metaloproteinases da matriz (MMP)-2, MMP-8, fator de crescimento de hepatócitos e fator de crescimento endotelial vascular, avaliados por Bioplex. Níveis elevados de RNAm da gingipaína e P3, expressão reduzida do RNAm da dentilisina (P < 0,05), bem como redução significativa (P < 0,05) dos níveis de inibidores de protease secretados por leucócitos e elafina (avaliados por ELISA), também foram associados à superexpressão do PAR2. Sítios periodontalmente saudáveis de indivíduos com periodontite crônica apresentaram uma menor expressão do RNAm e proteica do PAR2 (P < 0,05). O tratamento periodontal resultou na diminuição significativa da expressão de PAR2 (P < 0,05), correlacionada com a diminuição da expressão de mediadores inflamatórios (P < 0,05), bem como com suas proteases ativadoras (P < 0,05). Além disso, o uso do antagonista do PAR2 suprimiu significativamente (P < 0,05) a produção de superóxido em neutrófilos do sangue periférico humano, denotando o papel do PAR2 nessa importante função celular. Dessa forma, concluímos que o tratamento periodontal, o qual resulta na diminuição dos níveis de proteases e mediadores pró-inflamatórios, está associado com uma diminuição da expressão do PAR2, portanto, sugerindo que a expressão de PAR2 é influenciada pela presença da infecção periodontal, e não uma característica constitutiva favorecendo a inflamação periodontal.

Protease-activated receptor-2 (PAR2) is implicated in the pathogenesis of chronic inflammatory diseases including periodontitis; it can be activated by gingipain, produced by Porphyromonas gingivalis (P. gingivalis), and by neutrophil-protease 3 (P3). PAR2 activation plays a relevant role in inflammatory processes by inducing the release of important inflammatory mediators associated with periodontal breakdown. In the present study, the effect of non-surgical periodontal treatment on PAR2 expression and its association with levels of pro-inflammatory mediators, and activating proteases were investigated in chronic periodontitis patients. Moreover it was evaluated in vitro the role of MAPK-p38 signaling pathway during PAR2 activation and its influence on superoxide production and phagocytosis capacity in peripheral human neutrophils infected with P. gingivalis. A significant mRNA and protein over-expression of PAR2 (P < 0.05) in gingival crevicular fluid cells was positively associated to inflammatory clinical parameters, and to the levels of interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, matrix metalloproteases (MMP)-2, MMP-8, hepatocyte growth factor, and vascular endothelial growth factor (evaluated by Bioplex). Elevated levels of gingipain and P3 (P < 0.05), and decreased levels of dentilisin mRNA and protease inhibitors, secretory leucocyte protease inhibitor and elafina (P < 0.05) (evaluated by ELISA), were also associated to PAR2 overexpression. Periodontally healthy sites from chronic periodontitis individuals showed a diminished expression of PAR2 mRNA and PAR2 protein level (P < 0.05). Furthermore, periodontal treatment resulted in decreased PAR2 expression (P < 0.05), correlated with decreased expression of inflammatory mediators (P < 0.05) and activating proteases (P < 0.05). Moreover, PAR2 antagonist reduced significantly superoxide production in human neutrophils (P < 0.05) showing the role of PAR2 on this important cellular function. We concluded that periodontal treatment resulted on decreased levels of proteases, and pro-inflammatory mediators is associated to decreased PAR2 expression, therefore suggesting that PAR2 expression is influenced by the presence of periodontal infection, and not a constitutive characteristic favoring periodontal inflammation.

Aspectos relacionados ao câncer oral de interesse na periodontia / Oral cancer related aspects of interest in periodontics

Dentre as doenças mais comuns que afetam a cavidade oral, o câncer é a terceira condição mais frequente, ficando logo após a cárie e a doença periodontal. A etiologia do câncer está associada principalmente a mutações genéticas que proporcionam mudanças nas funções celulares. Fatores comportamentais como uso do álcool e tabaco constituem os principais fatores de risco para o câncer da cavidade oral. A importância do conhecimento sobre os tipos e a etiopatogenia das neoplasias da cavidade oral implica principalmente no correto diagnóstico e na detecção de pacientes de alto risco, bem como na utilização de medidas preventivas no controle dessa doença. O planejamento e o tratamento odontológico prévio e posteriores às intervenções das neoplasias orais são de fundamental importância e nesse aspecto, a detecção de patologias, como a doença periodontal, que possam estar associadas direta ou indiretamente a essas lesões podem interferir na complexidade dessa doença e no seu tratamento.

Within the most common diseases that occur in the oral cavity, cancer is the third most frequent condition, right after tooth decay and periodontal disease. The etiology of cancer is mainly associated with genetic mutations which provide changes in cellular functions. Behavioral factors such as alcohol and tobacco consumption are the major risk factors for oral cancer. The importance of knowledge about the types and pathogenesis of tumors of the oral cavity involves primarily the correct diagnosis and detection of patients at high risk as well as the use of preventive measures for the control of this disease. The planning and dental treatment prior and subsequent to the therapeutic interventions of oral cancer are essential and in this respect, the detection of pathologies such as periodontal disease, which direct or indirectly interfere with the complexity of this disease and its treatment

Efficacy of high intensity diode laser as an adjunct to non-surgical periodontal treatment: a randomized controlled trial.

The high intensity diode laser has been studied in periodontics for the reduction of subgingival bacteria in non-surgical treatment. Our study evaluated the bacterial effect as well as changes in periodontal clinical parameters promoted by root scaling and planing associated with this wavelength. Twenty-seven patients randomly assigned in two groups underwent root scaling and planing on the tested sites, and only the experimental group received the diode laser irradiation. Among the clinical parameters studied, the clinical probing depth (CPD) and the clinical attachment level (CAL) resulted in significant enhancement in the control group when compared with the experimental group (P = 0.014 and P = 0.039, respectively). The results were similar for both groups regarding the plaque index (PI) and bleeding on probing (BP). No significant difference in the microbiological parameters was observed between the control and experimental groups. It was possible to conclude that the high power diode laser adjunct to the non-surgical periodontal treatment did not promote additional effects to the conventional periodontal treatment.

Terapia fotodinâmica em periodontia clínica / Photodynamic therapy in periodontics

O objetivo do tratamento periodontal é restabelecer a saúde dos tecidos periodontais, através da eliminação e controle dos fatores etiológicos, reduzindo a agressão microbiana. Alguns microrganismos persistem na superfície radicular mesmo após a raspagem. Dessa maneira, o tratamento mecânico convencional pode falhar em reduzir o número dos periodontopatógenos a níveis compatíveis com saúde. O objetivo deste estudo é analisar estudos clínicos que empregaram a Terapia Fotodinâmica (PDT) no tratamento não-cirúrgico da periodontite. A literatura atual mostrou seis ensaios clínicos que empregaram a PDT como coadjuvante ao tratamento não-cirúrgico de periodontite crônica, que apresentaram resultados controversos em relação ao benefício adicional da PDT no tratamento periodontal. Mais estudos são necessários para que se estabeleça um consenso a respeito do uso da PDT na prática clínica.

The goal of periodontal treatment is to restore tissue health through the elimination and control of etiologic factors, reducing the microbial aggression. Some microorganisms persist in the root surface even after scaling. Thus, the conventional mechanical treatment may fail to reduce the number of periodontal pathogens to levels compatible with health. The objective of this study is to analyze clinical studies that used Photodynamic Therapy (PDT) in non-surgical treatment of periodontitis. The current literature showed six clinical trials that used PDT as an adjuvant to non-surgical treatment of chronic periodontitis, which showed controversial results regarding the added benefit of PDT in treating periodontal disease. More studies are needed to establish a consensus regarding the use of PDT in clinical practice.

Laser de diodo de alta potência como adjunto ao tratamento periodontal: ensaio clínico randomizado / High-intensity diode laser as adjunct to periodontal therapy: randomized clinical trial

O laser de diodo de alta potência tem sido estudado em Periodontia para redução microbiana como coadjuvante ao tratamento não cirúrgico. O objetivo deste ensaio clínico aleatório de boca-dividida foi avaliar a redução bacteriana e as mudanças nos parâmetros clínicos periodontais promovidas pela raspagem, associada ao laser de diodo de alta potência. Foram selecionados trinta e seis (36) pacientes, de ambos os sexos e portadores de periodontite crônica. Cada paciente forneceu um par de dentes unirradiculares contralaterais com profundidade clínica de sondagem (PCS) 5mm. Os pacientes passaram por tratamento periodontal prévio e em seguida os dentes experimentais foram divididos em dois grupos: teste e controle. Ambos receberam raspagem, alisamento e polimento coronário radicular (RAPCR), sendo que apenas o grupo teste recebeu a irradiação do laser de diodo (1,5W, contínuo, 1.193,7 W/cm2, 20 segundos) em duas sessões, com intervalo de uma semana.

Os parâmetros clínicos e microbiológicos foram coletados no início e 6 semanas após o tratamento. Houve redução significativa para todos os parâmetros clínicos estudados em ambos o grupos, entretanto os parâmetros PCS e Nível Clínico de Inserção (NCI) demonstraram melhora estatisticamente significante no grupo controle quando comparado ao grupo teste. Em relação às Unidades Formadoras de Colônias (UFCs) de bactérias totais (BT) e pigmentadas de preto (BPP) foi observada redução em ambos os grupos, porém sem diferença significante entre eles. Não houve diferença significativa entre os grupos em relação à presença de Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) e Prevotella intermedia (P. intermedia), entretanto a redução no número de pacientes que apresentaram Porphyromonas gingivalis (P. gingivalis) foi significativamente maior no grupo controle. Foi concluído que a irradiação do laser de diodo de alta potência, em bolsas de dentes unirradiculares, não proporcionou melhora clínica e microbiológica adicional ao procedimento convencional

The high intensity diode laser has been studied in periodontics for microbial reduction in non-surgical treatment as an adjunct to scaling procedures. The goal of this randomized clinical trial was to assess the bacterial reduction and changes in clinical periodontal parameters promoted by scaling, combined with high intensity diode laser. Thirty six (36) subjects, of both gender and with chronic periodontitis were selected. Each patient provided a pair of contra-lateral singles rooted teeth, with probing pocket depth (PPD) 5 mm. Patients underwent periodontal treatment prior and then the teeth were divided into two experimental groups: test and control. Both received scaling and root planing (SRP), and only the test group received irradiation of diode laser (1.5W, continuous, 1.193,7 W/cm2, 20 seconds) in two sessions, with break of one week. Clinical and microbiological data were collected at baseline and 6 weeks after treatment. There was a significant decrease for all clinical parameters studied in both groups, but the parameters PPD and clinical attachment level (CAL) showed statistically significant improvement in the control group compared to the test group

Concerning Colony Forming Units (CFU) of total bacteria and black pigmented colonies, reduction was observed in both groups but no significant difference was observed between them. There was no significant difference between the groups regarding the presence of P. intermedia and A. actinomycetemcomitans, however the decrease in the number of patients who had P. gingivalis was significantly higher in the control group. It was concluded that irradiation with the high intensity diode laser, in periodontal pockets of single- rooted teeth, did not provide additional clinical and microbiological improvement.

Radiographic alveolar bone loss in patients undergoing periodontal maintenance.

The aim of the present cross-sectional investigation was to evaluate percentage of bone loss in patients who had been one year under periodontal maintenance at the Department of Periodontology, Faculty of Dentistry, University of São Paulo by radiographic analysis. Complete sets of periapical radiographs provided data regarding percentage of alveolar bone loss, which was correlated with arches, tooth group and proximal sites. The sample consisted of 27 men and 53 women ranging in age from 16 to 85 years (mean: 48.3 years). A total of 1,120 periapical radiographs (1,970 teeth) were digitized and analyzed with the Image Tool software (University of Texas Health Science Center). Bone loss was defined as when the distance between the cemento-enamel junction and the alveolar bone crest was greater than 2 mm. Two examiners (p<0.0001) performed radiographic measurements of bone loss. The Greenhouse-Geisser normality test and a univariate analysis of variance were used for statistical analysis. Mean bone loss was 20.60% (+/-12.12). The highest level of bone loss was observed on the distal surface and in the upper arch, as well as in the upper incisors and molars.

Mensuração da perda óssea alveolar em radiografias: quais são os recursos disponíveis na prática clínica? / Measurement of alveolar bone loss and methods available in pratical clinic

É indiscutível a importância do exame radiográfico conjugado ao exame clínico na avaliação e no tratamento das doenças periodontais. As radiografias intra-bucais são rotineiramente utilizadas na clínica para dar suporte ao diagnóstico, ao plano de tratamento, ao prognóstico e, finalmente, à análise, a longo prazo, do resultado do tratamento instituído (ARMITAGE, 1996). Esta revisão revelou que, na prática clínica, as radiografias periapicais e interproximais são as mais utilizadas quando o objetivo é mensurar a perda óssea alveolar. Essas imagens aparecem sempre associadas a sondas periodontais milimetradas (convencionais ou eletrônicas), lupas, réguas, compassos de ponta seca, telas milimetradas e programas de computador. Adicionalmente, observou-se que a ausência de integridade do tecido ósseo foi descrita sempre que a distância entre a junção esmalte cemento (JCE) e a crista óssea alveolar (COA) se apresentava > 2 mm.