Cell sheet produced from periodontal ligament stem cells activated by PAR1 improves osteogenic differentiation

Abstract Periodontal regeneration is a challenge, and tissue engineering based on periodontal ligament stem cells (PDLSCs) has been shown to be a promising alternative to this process. However, the need for scaffolds has limited the therapeutic use of PDLSCs. In this context, scaffold-free tissue engineering using the cell sheet (CS) technique has been developed as an alternative approach to improve tissue regeneration. Previously, we showed that Protease-activated receptor-1 (PAR1) can regulate PDLSCs. Herein, we evaluate whether PAR1 influences osteogenesis in CSs produced from PDLSCs, without the use of scaffolds. PDLSCs were isolated and immunophenotyped. Then, CSs were obtained by supplementing the culture medium with ascorbic acid (50 µg/mL), and PAR1 was activated through its agonist peptide (100 nM). Scaffold-free 3D CSs were successfully produced from PDLSCs, and they showed higher proliferation potential than isolated PDLSCs. Also, PAR1 activation decreased senescence and improved osteogenic differentiation of CSs by increasing mineralized nodule deposition and alkaline phosphatase concentration; PAR1 also modulated osteogenic markers at the gene and protein levels. We further demonstrated that this effect was regulated by Wnt, TGF-βI, MEK, p38 MAPK, and FGF/VEGF signaling pathways in PDLSCs (p < 0.05%). Overall, PAR1 activation increased osteogenic activity in CSs, emerging as a promising scaffold-free therapeutic approach for periodontal regeneration.

Protease-activated receptor type 2 activation downregulates osteogenesis in periodontal ligament stem cells

Abstract Protease-activated receptor-2 (PAR2) is associated with the pathogenesis of many chronic diseases with inflammatory characteristics, including periodontitis. This study aimed to evaluate how the activation of PAR2 can affect the osteogenic activity of human periodontal ligament stem cells (PDLSCs) in vitro. PDLSCs collected from three subjects were treated in osteogenic medium for 2, 7, 14, and 21 days with trypsin (0.1 U/mL), PAR2 specific agonist peptide (SLIGRL-NH2) (100 nM), and PAR2 antagonist peptide (FSLLRY-NH2) (100 nM). Gene (RT-qPCR) expression and protein expression (ELISA) of osteogenic factors, bone metabolism, and inflammatory cytokines, cell proliferation, alkaline phosphatase (ALP) activity, alizarin red S staining, and supernatant concentration were assessed. Statistical analysis of the results with a significance level of 5% was performed. Activation of PAR2 led to decreases in cell proliferation and calcium deposition (p < 0.05), calcium concentration (p < 0.05), and ALP activity (p < 0.05). Additionally, PAR2 activation increased gene and protein expression of receptor activator of nuclear factor kappa-Β ligand (RANKL) (p < 0.05) and significantly decreased the gene and protein expression of osteoprotegerin (p <0. 05). Considering the findings, the present study demonstrated PAR2 activation was able to decrease cell proliferation, decreased osteogenic activity of PDLSCs, and upregulated conditions for bone resorption. PAR2 may be considered a promising target in periodontal regenerative procedures.

Protease-activated receptor type 1 (PAR1) increases CEMP1 gene expression through MAPK/ERK pathway

Abstract: PAR1 is a G-coupled protein receptor that regulates several cellular metabolism processes, including differentiation and proliferation of osteogenic and cementogenic related cells and our group previously demonstrated the regenerative potential of PAR1 in human periodontal ligament stem cells (hPDLSCs). In this study, we hypothesized that PAR1 regulates the cementogenic differentiation of hPDLSCs. Our goal was to identify the intracellular signaling pathway underlying PAR1 activation in hPDSLC differentiation. hPDLSCs were isolated using the explant technique. Cells were cultured in an osteogenic medium (OST) (α-MEM, 15% fetal bovine serum, L-glutamine, penicillin, streptomycin, amphotericin B, dexamethasone, and beta-glycerophosphate). The hPDLSCs were treated with a specific activator of PAR1 (PAR1 agonist) and blockers of the MAPK/ERK and PI3K pathways for 2 and 7 days. The gene expression of CEMP1 was assessed by RT-qPCR. The activation of PAR1 by its agonist peptide led to an increase in CEMP1 gene expression when compared with OST control. MAPK/ERK blockage abrogated the upregulation of CEMP1 gene expression induced by PAR1 agonist (p < 0.05). PI3K blockage did not affect the gene expression of CEMP1 at any experimental time (p > 0.05). We concluded that CEMP1 gene expression increased by PAR1 activation is MAPK/ERK-dependent and PI3K independent, suggesting that PAR1 may regulate cementogenetic differentiation of hPDLSCs.

Cytotoxicity and cytokine production by calcium silicate-based materials on periodontal ligament stem cells

Abstract This study investigated the effect of three commercial calcium silicate-based materials (CSBM) on cytotoxicity and pro-and anti-inflammatory cytokines production in cultured human periodontal ligament stem cells (hPDLSCs). Culture of hPDLSCs was established and characterized. Extracts of Bio-C Sealer (Angelus, Londrina, PR, Brazil), MTA Fillapex (Angelus, Londrina, PR, Brazil) and PBS Cimmo HP (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brazil) were prepared by placing cement specimens (5 x 3 mm) in culture medium. Then, the extracts were serially two-fold diluted (1, 1:2, 1:4, 1:8, 1:16) and inserted into the cell-seeded wells for 24, 48 and 72 h for MTT assays. TNF-α and IL-10 cytokines were quantified by ELISA at 24h-cell supernatants. Data were analyzed by ANOVA and Tukey's test (α = 0.05). All CSBM exhibited some cytotoxicity that varied according to extract concentration and time of evaluation. MTA Fillapex presented the highest cytotoxic effects with significant reduction of metabolic activity/cell viability when compared to Bio-C Sealer and Cimmo HP®. TNF-α was significantly upregulated by the three tested cements (p < 0.05) while only MTA Fillapex significantly upregulated IL-10 in comparison to control. Taken collectively, the results showed that PBS Cimmo HP®, Bio-C Sealer and MTA Fillapex present mild and transient cytotoxicity and slightly induced TNF-α production. MTA Fillapex upregulated IL-10 release by hPDLSCs.

Resumo Este estudo investigou o efeito de três materiais comerciais à base de silicato de cálcio (CSBM) na citotoxicidade e na produção de citocinas pró e antiinflamatórias em células-tronco do ligamento periodontal humano (hPDLSCs). Cultura de hPDLSCs foi estabelecida e caracterizada. Extratos de Bio-C Sealer (Angelus, Londrina, PR, Brasil), MTA Fillapex (Angelus, Londrina, PR, Brasil) e PBS Cimmo HP® (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brasil) foram preparados com a colocação de espécimes dos cimentos (5 x 3 mm) em meio de cultura. Em seguida, os extratos foram diluídos (1, 1: 2, 1: 4, 1: 8, 1:16) e inseridos nos poços semeados de células para ensaio de citotoxicidade por meio de MTT por 24, 48 e 72 h. As citocinas TNF-α e IL-10 foram quantificadas por ELISA em sobrenadantes de células de 24 h. Os dados foram analisados por ANOVA e teste de Tukey (α = 0,05). Todos os CSBM exibiram alguma citotoxicidade que variou de acordo com a concentração do extrato e o tempo de avaliação. O MTA Fillapex apresentou os maiores efeitos citotóxicos com redução significativa da atividade metabólica / viabilidade celular quando comparado ao Bio-C Sealer e Cimmo HP®. O TNF-α foi regulado positivamente pelos três cimentos testados (p <0,05), enquanto apenas o MTA Fillapex regulou positivamente a liberação de IL-10 em comparação com o controle. Tomados em conjunto, os resultados mostraram que PBS Cimmo HP®, Bio-C Sealer e MTA Fillapex apresentam citotoxicidade leve e transitória e induziram a produção de TNF-α. O MTA Fillapex regulou positivamente a liberação de IL-10 por hPDLSCs.

Effect of magnification on root coverage surgery: a systematic review

Root coverage surgery can be performed in patients with gingival recession to cover the exposed root aiming to control hypersensitivity and promotes better aesthetic. Optical magnification has been proposed as a refinement in this surgical technique to increase root coverage. This approach may lead to enhanced soft tissue stability, less post-operative discomfort, better predictability and esthetic appearance. Aim: This systematic review aimed to evaluate the effectiveness of magnification on root coverage surgery when compared to procedures performed without magnification. Methods: Randomized controlled trials with a follow-up of at least 6 months that compared surgeries for root coverage performed under optic magnification versus conventional (macro) root coverage surgery were screened. The primary outcome was mean root coverage (mm) (MRC) and secondary outcomes were percentage of root coverage (PRC) and complete root coverage (CRC). Results: Of 569 papers relevant to this review, seven were included. Meta-analysis showed that the use of magnification may favor greater PRC (7.38%, 95% CI 3.66-11.09). Conclusion: Magnification can increase PRC in root coverage surgeries. More randomized trials with the use of magnification may be necessary to verify if this benefit is clinically relevant, in order to justify the use of this device

Root canal dressings for revascularization influence in vitro mineralization of apical papilla cells

Abstract Endodontic revascularization is based on cell recruitment into the necrotic root canal of immature teeth after chemical disinfection. The clinical outcome depends on the ability of surviving cells from the apical tissue to differentiate and promote hard tissue deposition inside the dentinal walls. Objective To investigate the effect of calcium hydroxide (CH) and modified triple antibiotic paste (mTAP - ciprofloxacin, metronidazole and cefaclor) on the viability and mineralization potential of apical papilla cells (APC) in vitro . Material and Methods APC cultures were kept in contact with CH or mTAP (250-1000 µg/mL) for 5 days, after which cell viability was assessed using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Next, APCs were subjected to CH or mTAP at 250 µg/mL for 5 days before inducing the differentiation assay. After 14 and 21 days, calcium deposition was assessed by the Alizarin Red S staining method, followed by elution and quantification using spectrophotometry. Data were analyzed using ANOVA followed by Tukey post hoc test. Results CH induced cell proliferation, whereas mTAP showed significant cytotoxicity at all concentrations tested. APC treated with CH demonstrated improved mineralization capacity at 14 days, while, for mTAP, significant reduction on the mineralization rate was observed for both experimental periods (14 and 21 days). Conclusion Our findings showed that CH induces cell proliferation and improves early mineralization, whereas mTAP was found cytotoxic and reduced the mineralization potential in vitro of APCs.

Moduladores da resposta do hospedeiro como adjuvantes no tratamento da doença periodontal / Modulators of the host response as adjuvants in the treatment of periodontal disease

Durante anos, o tratamento periodontal esteve voltado apenas para remoção do agente etiológico principal. No entanto, visto que o sistema imunoinflamatório do hospedeiro (patogênese da doença periodontal) é o principal responsável por promover a destruição dos tecidos periodontais, o uso de agentes que modulem essa resposta foi introduzido com o objetivo de melhores resultados no controle da doença. Dentre os Moduladores da Resposta do Hospedeiro (MRH), destacam-se a doxiciclina em dose subantimicrobiana, os anti-inflamatórios não esteroidais, bifosfonatos, agentes inibidores de citocinas, os moduladores da síntese de óxido nítrico e as lipoxinas. Desta forma, diante da grande importância que os MRH podem ter no controle da doença periodontal, o objetivo desta revisão é abordar diversas características e peculiaridades dos principais MRH adjuvantes no tratamento da doença periodontal, a fim de viabilizar seu uso na prática clínica (AU)

For a long time, periodontal treatment was only focused on removal of the main etiologic agent. However, since the host immunoinflammatory system (pathogenesis of periodontal disease) is the main responsible for promoting the destruction of periodontal tissues, the use of agents that modifies its response was introduced to obtain better results on disease control. Among the modulators of the host response (MHR), stand out subantimicrobial dose doxycycline, non-steroidal anti-inflammatory drugs, bisphosphonates, cytokine inhibitors, nitric oxide synthesis modulators and lipoxins. Thus, in view of the great importance that MHR may have on control of periodontal disease, the purpose of this review is to address several characteristics and peculiarities of the main adjuvant MHRs to treat periodontal disease, in order to make than feasible to use in clinical practice. (AU)

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.

Effects of periodontal treatment on primary sjogren's syndrome symptoms

Abstract The aim of this longitudinal prospective study was to evaluate the effects of periodontal treatment on the clinical, microbiological and immunological periodontal parameters, and on the systemic activity (ESSDAI) and subjective (ESSPRI) indexes in patients with primary Sjögren’s Syndrome (pSS). Twenty-eight female patients were divided into four groups: pSS patients with or without chronic periodontitis (SCP, SC, respectively), and systemically healthy patients with or without chronic periodontitis (CP, C, respectively). Periodontal clinical examination and immunological and microbiological sample collection were performed at baseline, 30 and 90 days after nonsurgical periodontal treatment (NSPT). Levels of interleukin IL-1β, IL-8 and IL-10 in saliva and gingival crevicular fluid (GCF) were evaluated by ELISA, as well as the expression of Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans, (Aa) Tannerella forsythia (Tf), and Treponema denticola (Td), by qPCR. Systemic activity and pSS symptoms were evaluated by ESSDAI and ESSPRI. NSPT resulted in improved periodontal clinical parameters in both SCP and CP groups (p>0.05). Pg, Aa, and Tf levels decreased after NSPT only in CP patients (p<0.05). Significantly greater levels of IL-10 in GCF were verified in both SCP and CP groups (p<0.05). SCP patients showed increased salivary flow rates and decreased ESSPRI scores after NSPT. In conclusion, NSPT in pSS patients resulted in improved clinical and immunological parameters, with no significant effects on microbiological status. pSS patients also showed increased salivary flow and lower ESSPRI scores after therapy. Therefore, it can be suggested that NSPT may improve the quality of life of pSS patients.

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)

Aspectos relevantes da síndrome de Sjõgren para o cirurgião-dentista / Sjogren’s syndrome’s relevant aspects for the dental surgeon

A síndrome de Sjõgren (SS), conhecida como síndrome sicca, é uma doença autoimune caracterizada pela hipofunção das glândulas salivares e lacrimais, cuja prevalência na população mundial é de aproximadamente 0,5% a 1%. Por ser uma doença autoimune complexa e de difícil diagnóstico, é sub-diagnosticada e sub-tratada segundo o consenso realizado em 2012 pelo Colégio Americano de Reumatologia (ACR). O Cirurgião-Dentista pode desempenhar papel importante na detecção de possíveis alterações compatíveis com a síndrome, além de auxiliar no tratamento de diversas patologias orais decorrentes da síndrome. Este trabalho tem como objetivo explanar aspectos importantes referentes ao diagnóstico e tratamento da síndrome aqui discutida. A SS apesar de ser considerada uma doença de evolução lenta, em estágios avançados pode ser fatal, principalmente por aumentar as chances dos pacientes virem a desenvolver linfoma não Hodking. O tratamento odontológico dos pacientes com SS deve principalmente ser profilático, com a recomendação do uso de repositores de saliva e controle rígido da higiene bucal.

Sjogren’s syndrome (SS), known as the sicca syndrome, is an autoimmune disease characterized by salivary and lacrimal glands hypofunction which prevalence in the world population is approximatel y around 0,5% to 1%. For being a complex autoimmune disease and with difficult diagnosis, it is sub diagnosed and miss treated according to the consensus occurred in 2012 by the American College of Rheumatology (ACR). The surgeon-dentist (SD) may play a important role on the detection of possible changes compatible to the syndrome, besides can help in the treatment of many oral pathologies caused by the syndrome. This work has the main purpose to explain the important aspects regards to the correct diagnosis and treatment of this syndrome.The SS besides been considered a slow evolution disease, in advanced stages it can be fatal,mainly for increasing the patient’s chances of developing non-Hodking lymphoma. The dental treatment of patients with SS must be prophylactic, with the recomedations of the use of salivary replenishing and careful control of the oral hyigiene.

Condição bucal de hepatopatas pré- transplantados e transplantados hepáticos: revisão da literatura / Oral Health Status of liver transplant candidates and post–liver transplant patients: a literature review

O transplante de fígado é o tratamento preconizado para a doença hepática terminal. Infecções são complicações frequentes e estão associadas à alta morbidade e mortalidade de pacientes pré e pós-transplantados. Assim, a prevenção de processos infecciosos é fundamental para reduzir a progressão da cirrose e diminuir o risco de complicações após o transplante. Portanto, o objetivo desta revisão de literatura é verificar quais são as condições bucais de candidatos ao transplante de fígado e de pós-transplantados, bem como verificar se a doença hepática está associada com pior condição bucal. Os artigos incluídos demonstraram higiene bucal ruim, alta prevalência de doença periodontal e de doença cárie. Alguns estudos observaram maior perda óssea e maior perda de inserção clínica em pré e pós-transplantados do que em pacientes sadios. A literatura é controversa em relação à associação entre condição hepática e doença cárie. Não há evidência suficiente para suportar a hipótese de que a doença hepática seja um fator de risco para doenças bucais

Liver transplantation is the indicated treatment for endstage hepatic disease. Infections are frequent complications in patients waiting for liver transplant and post-transplant patients, and have been associated with high morbidity and mortality.Thus, prevention of infections is important in the reduction of the progression of hepatic disease and in the reduction of complications in the transplanted patient. The aim of the review is to describe the oral conditions of liver transplant candidates and transplanted patients, and to verify if hepatic disease is associated with poor oral conditions. The included articles demonstrated poor oral hygiene, high prevalence of periodontal disease and caries disease. Some of the studies observed greater bone loss and clinical attachment loss in liver transplant candidates and transplanted patients, when compared to healthy controls. The literature is controversial regarding association between liver disease and dental caries. We concluded that there is not enough evidence to support the hypothesis that liver disease increases the risk for oral diseases

Diabetes mellitus: o que os periodontistas devem saber / Diabetes Mellitus: what periodontists must know

A doença periodontal, uma doença infecto-inflamatória crônica que pode levar à perda dentária, é considerada a sexta principal complicação que ocorre no paciente diabético, podendo ter sua susceptibilidade aumentada em até três vezes para esse tipo de paciente. Assim como o diabetes aumenta o risco para periodontite, na via contrária, a periodontite dificulta o controle metabólico pelo paciente diabético. O Diabetes do tipo 2 tem se tornado uma epidemia com prevalência crescente em todo o mundo, afetando aproximadamente 382 milhões de pessoas e acredita-se que até 2035 esse número aumente para 592 milhões. O Diabetes Mellitus é uma das principais causas de mortalidade, insuficiência renal, amputação de membros inferiores, cegueira e doença cardiovascular, além de apresentar perda importante de qualidade de vida. Baseados nesses números e na relação bidirecional existente entre essas doenças, nós acreditamos na necessidade do entendimento do diabetes pelo periodontista...

Periodontal disease, a chronic infectious inflammatory disease that can lead to tooth loss, is considered the sixth major complication that occurs in diabetic patients, and may increase susceptibility up to three times for this type of patient. As diabetes increases the risk for periodontitis, periodontitis in the opposite direction complicates metabolic control by the diabetic patient. Type 2 diabetes has become an epidemic with increasing prevalence worldwide affecting approximately 382 million people, and it is believed that by 2035 this number will reach 592 million. Diabetes mellitus is a major cause of mortality, renal failure, lower limb amputation, blindness and cardiovascular disease, as well as significant loss of quality of life. Based on these numbers and the existing bidirectional relationship between these two diseases, we believe the need that periodontists have to understand diabetes mellitus...

Laser de baixa potência na periodontia: uma revisão do estado atual do conhecimento / Low power laser in periodontics: a review of knowledge of the current state of knowledge

O uso do laser de baixa potência como instrumento terapêutico vem sendo amplamente incorporado na Medicina e na Odontologia, pois este tem se mostrado um importante auxiliar em tratamento de processos inflamatórios devido à capacidade de imunomodulação dos tecidos. A irradiação com laser excita uma série de moléculas presentes nas mitocôndrias, principalmente os: citocromo c oxidase e superóxido dismutase (NADH), responsáveis pela absorção da luz vermelha e infravermelha. Essas moléculas absorvem a luz e aceleram a transferência de elétrons na cadeia respiratória mitocondrial, aumentando a produção de trifosfato de adenosina (ATP). Devido a essa propriedade, o laser de baixa potência na odontologia é muito bem indicado para as mais diversas especialidades, principalmente na periodontia. Diversos estudos clínicos comprovam que o uso do laser atua como coadjuvante na melhora da resposta inflamatória em diversas situações clínicas como na raspagem subgengival e na reparação de cirurgias periodontais...

The use of low power laser as a therapeutic tool has been widely incorporated in medicine and dentistry, because it has been an important aid in the treatment of inflammatory processes due to its ability of immuno - modulation of tissues . The laser irradiation excites a number of molecules present in the mitochondria especially : cytochrome c oxidase and superoxide dismutase (NADH) responsible for absorption of red and infrared light. These molecules absorb light and accelerate the transfer of electrons in the mitochondrial respiratory chain increasing the production of adenosine triphosphate (ATP). Due to this property, the low-power laser in dentistry is well suited to the most diverse specialties especially in periodontics . Several clinical studies have shown that the use of laser acts as an adjuvant to improve the inflammatory response in many clinical situations such as subgingival scaling and repair of periodontal surgery...

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

Prevalência microbiana e quantificação da arginase na saúde e doença periodontal / Microbial prevalence and arginase quantification in health and periodontal disease

A arginase salivar está aumentada em processos inflamatórios e infecciosos da cavidade bucal. O objetivo do presente estudo foi avaliar a atividade de arginase salivar, correlacionando-a a parâmetros clínicos e microbiológicos em diferentes condições periodontais. Foram avaliados os seguintes parâmetros clínicos: índice de placa, índice de sangramento, profundidade de sondagem e nível de inserção clínica. Foi avaliada ainda a presença dos periodontopatógenos Campylobacter rectus, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tanerella forsythia, Treponema denticola e Prevotella intermedia por meio da reação em cadeia da polimerase (PCR). Finalmente, a presença salivar de arginase — por meio de espectrofotometria —também foi considerada. O tratamento estatístico dos dados foi realizado pelos testes Qui-quadrado e Kruskal-Wallis, adotando-se significância estatística quando p<0,05. Foram alocados no presente estudo 78 indivíduos assim caracterizados: 26 periodontalmente saudáveis (S), 26 com gengivite(G) e 26 com periodontite crônica (P). P. gingivalis, P. intermedia e T. denticola estavam mais prevalentes significativamente em P do que em G e S (p<0,05). A. actinomycetemcomitans foi significativamente mais prevalente (p<0,05) em P e G do que em S. C. rectus apresentou distribuição similar nos três grupos (p>0,05). Com relação aos níveis de atividade de arginase, os indivíduos portadores de periodontite crônica apresentaram maiores níveis (p<0,05) em comparação aos com gengivite ou periodontalmente saudáveis. A expressão da arginase salivar parece acompanhar a mudança dos sinais clínicos e a alteração do perfil microbiológico das diferentes condições periodontais

The salivary arginase is increased in inflammatory and infectious processes of the oral cavity. The aim of this study was to evaluate the salivary arginase activity, correlating it to clinical and microbiological parameters in different periodontal conditions. We evaluated the following parameters: plaque index, bleeding index, probing depth and clinical attachment level. It also assessed the presence of periodontopathogens Campylobacter rectus, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tanerellaforsythia, Treponema denticola, and Prevotella intermedia by polymerase chain reaction (PCR). Finally, presence of salivary arginase - by spectrophotometry - was also considered. Statistical treatment of data was performed by chi-square and Kruskal-Wallis, adopting statistical significance at p <0.05. Eighty-nine individuals were allocated in this study:26 periodontally healthy (S), 26 with gingivitis (G) and 26 with chronic periodontitis (P). P. gingivalis, P. intermedia and T. denticola were significantly more prevalent in P-group than G- and S-group (p <0.05). A. actinomycetemcomitans was significantly more prevalent (p <0.05) in P- and G-group than in S-group. C. rectus showed a similar distribution in the three groups (p> 0.05). With respect to the levels of arginase activity, individuals with chronic periodontitis had higher levels (p <0.05) than those with gingivitis or periodontally healthy. Expression of the salivary arginase seems to followthe changes of clinical signs and microbiological profile in different periodontal conditions.

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 percent and were divided in 3 groups according to the bleeding index (BI): I) Low bleeding (< 30 percent), II) Medium bleeding (31 - 59 percent) and III) High bleeding (> 60 percent). The presence of each pathogen was determined by PCR. The prevalence of Sm was 71.9 percent and the mean dmft/DMFT was 6.68. The prevalence in low, medium and high bleeding groups was 43.5 percent, 34.5 percent and 46.7 percent for Aa; 43.5 percent, 37.9 percent, and 36.7 percent for Cr; 99.1 percent, 100 percent, and 96.7 percent for Pg; 56.5 percent, 56.9 percent, and 66.7 percent for Pi; and 58.3 percent, 60.3 percent, and 56.7 percent for Tf, respectively. Pg (99.0 percent) was the most prevalent periodontal pathogen detected followed by Tf (58.7 percent), Pi (58.2 percent), Aa (41.3 percent) and Cr (40.8 percent). 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).

Cyclosporin a-induced new cementum formation: a morphometric evaluation in the periapical region of rats

Cyclosporin A (CsA) is a potent immunosuppressor used in organ transplantation and in the management of various autoimmune diseases. Recent studies have shown that CsA stimulates deposition of cementum on root surfaces. The aim of this study was to evaluate the periapical cementum thickness and the apical foramen width in CsA-treated rats. Rats weighing 50 g were treated with a daily injection of 10 mg/kg body weight of CsA in the chow for 60 days. The cementum of the mandibular 1st molars was histologically and morphometricaly examined by analysis of 5-æm-thick serial buccolingual paraffin sections stained with hematoxylin and eosin. Histometric and stereologic analyses revealed the presence of large amounts of cementum in all root surfaces, particularly abundant in the periapical region and obliterating the foramen. The volume density of cementoblasts did not increase. Five to 90 days after the termination of CsA therapy, there was no reduction of cementum thickness. These results suggest that cementum deposition is not reversible after cessation of CsA treatment.

Ciclosporina A (CsA) é um potente imunossupressor usado no transplante de órgãos e no tratamento de várias doenças auto-imunes. Recentes estudos têm demonstrado que a CsA estimula a deposição de cemento na superfície radicular. O objetivo deste estudo foi de avaliar a espessura do cemento periapical e largura do forame apical em ratos tratados com CsA. Os ratos pesavam 50 g e foram tratados com doses diárias de 10 mg/kg de peso corporal de CsA no período de 60 dias. O cemento do primeiro molar inferior foi examinado histologicamente e morfometricamente por análises de cortes em parafina com 5æm de espessura no sentido vestíbulo-lingual e corados com hematoxilina e eosina. As análises histométricas e estereológicas revelaram a presença de largos depósitos de cemento em todas as superfícies radiculares, particularmente maior na região periapical e obliterando o forame. A densidade volumétrica dos cementoblastos não foi aumentada. No período de 5 a 90 dias após o término da terapia com CsA, não houve redução na espessura do cemento. Estes resultados sugerem que o depósito de cemento não é reversível após o tratamento com CsA ser cessado.

Effects of long-term cyclosporin therapy on gingiva of rats: analysis by stereological and biochemical estimation

A ciclosporina A (CsA) é usada como um agente imunossupressor e promove efeitos colaterais como o crescimento gengival que permanece um problema significante. Alguns fatores de risco podem aumentar esses efeitos, como a duracão do tratamento. Ainda não há estudos estereológicos e bioquímicos explorando os efeitos de um longo período de terapia com CsA no tecido gengival. O objetivo do presente estudo foi investigar o nível de TGF-b1 na saliva e descobrir a densidade de fibroblastos e fibras colágenas no tecido gengival de ratos tratados por um longo período com CsA. Os ratos foram tratados por 60, 120, 180 e 240 dias com injecões subcutâneas diárias de 10 mg/kg de peso corporal de CsA. Ao final dos períodos experimentais, a saliva era coletada para determinacão do TGF-b1. Após o processamento histológico, o epitélio oral e a área do tecido conjuntivo foram medidos, bem como a densidade volumétrica dos fibroblastos (Vf) e das fibras colágenas (Vcf). Após 60 e 120 dias de tratamento com CsA ocorreu um significante aumento de Vf e Vcf, bem como aumento significante de TGF-b1. Após 180 e 240 dias, houve reducão do crescimento gengival associada com decréscimo significante do nível de TGF-b1, e também diminuicão observada de Vf e Vcf. Os dados presentes neste estudo sugerem que, após longo período de terapia, ocorre uma diminuicão do nível de TGF-b1, o que deve contribuir para um aumento na atividade proteolítica dos fibroblastos na gengiva, favorecendo a normalidade da síntese da matriz extracelular.

Avaliação de uma nova hidroxiapatita no tratamento de defeitos ósseos: observações histológicas em tíbias de ratos / Evaluation of a new hydroxyapatite in the treatment of osseous defects: histological observations in rat tibias

A hidroxiapatita é um biomaterial à base de fosfato de cálcio que tem sido extensivamente utilizado em várias aplicações odontológicas, visando à reconstrução óssea. O presente trabalho teve como objetivo avaliar comparativamente a eficácia de uma nova hidroxiapatita, desenvolvida no Brasil (HAF), em relação à eficácia de uma hidroxiapatita comercial (Osteogen®), no tratamento de defeitos ósseos cirurgicamente criados em tíbias de 60 ratos Holtzman. Após anestesia, as cavidades ósseas foram confeccionadas nas superfícies laterais das tíbias direita e esquerda e preenchidas comHAF (40 cavidades) ou Osteogen® (40 cavidades), enquanto outras 40 cavidades não foram preenchidas. Após o sacrifício, aos 7, 15, 30, 60 e 120 dias, realizou-se análise histológica descritiva. Ambas as hidroxiapatitas apresentaram biocompatibilidade. A regeneração no grupo controle foi mais rápida (60 dias) do que nos demais grupos. Nos primeiros períodos do experimento, as partículas de HAF e Osteogen® apresentavam-se envoltas por tecido conjuntivo fibroso. Nos períodos mais tardios (60 e 120 dias) observou-se semelhança histológica entre o grupo controle e o grupo Osteogen®, que se caracterizava pela presença de tecido ósseo compacto. Já no grupo HAF, apesar de haver formação óssea, ainda havia presença de material envolvido por tecido conjuntivo fibroso. As observações do presente trabalho demonstraram que, apesar de biocompatível, a hidroxiapatita HAF apresentou menor eficácia em relação ao Osteogen®, no que se refere à capacidade de reparar os defeitos ósseos criados em tíbias de ratos