Targeting Biomechanical Endurance of Dental-Implant Abutments Using a Diamond-Like Carbon Coating.

Abutment components (i.e., fixtures associated with oral implants) are essentially made of titanium (Ti), which is continuously exposed to the hash oral environment, resulting in scratching. Thus, such components need to be protected, and surface treatments are viable methods for overcoming long-term damage. Diamond-like carbon (DLC), an excellent protective material, is an alternative surface-treatment material for Ti abutments. Here, we demonstrate that a silicon interlayer for DLC film growth and the pulsed-direct current plasma-enhanced chemical vapor deposition (DC-PECVD) method enables the deposition of an enhanced protective DLC film. As a result, the DLC film demonstrated a smooth topography with a compact surface. Furthermore, the DLC film enhanced the mechanical (load-displacement, hardness, and elastic modulus) and tribological properties of Ti as well as increased its corrosion resistance (16-fold), which surpassed that of a bare Ti substrate. The biofilm formed (Streptococcus sanguinis) after 24 h exhibited an equal bacterial load (∼7 Log colony-forming units) for both the groups (Ti and DLC). In addition, the DLC film exhibited good cytocompatibility, owing to its noncytotoxicity toward human gingival fibroblast cells. Therefore, DLC deposition via DC-PECVD can be considered to be a promising protective and cytocompatible alternative for developing implant abutments with enhanced mechanical, tribological, and electrochemical properties.

Do smokers have a different gingival crevicular fluid cytokine/chemokine profile than nonsmokers in clinically healthy periodontal sites? A systematic review and meta-analysis.

OBJECTIVES: Assessing the evidence and comparing the levels of cytokines in gingival crevicular fluid (GCF) of periodontal healthy sites of smokers and nonsmokers. MATERIALS AND METHODS: Seven databases were surveyed for observational studies up to April 8, 2021. Studies comparing cytokine levels on GCF in periodontally healthy sites of smokers vs. nonsmokers were included in the study. The risk of bias was evaluated using NIH (2014) tool. For meta-analyses, levels in GCF were analyzed, followed by evidence certainty assessment using the GRADE approach. RESULTS: Eighteen studies were included for qualitative evaluation, and eight were included in meta-analysis. Qualitatively, despite high heterogeneity and risk of bias observed among the studies, most of them presented no significant difference in the gingival crevicular cytokine fluid levels between groups. Regarding meta-analyses, interleukin-8 (IL-8) and superoxide dismutase (SOD) levels in GCF were analyzed. The significant difference was observed only in SOD levels, where heavy smokers had lower levels compared to nonsmokers (MD - 30.06 [- 40.17, - 19.96], p = 0.07, 95%CI), as well as light smokers had lower levels compared to nonsmokers (MD - 15.22 [- 16.05, - 14.39], p < 0.00001, 95%CI). CONCLUSION: No distinct GCF cytokine profiles were detected for smokers and non-smokers. However, despite the limitations observed in the included studies, lower levels of SOD were identified in smokers. CLINICAL RELEVANCE: Indicating a distinct GCF profile of cytokines in periodontal healthy smokers may help to understand the mechanism whereby smoking may affect the host response.

Parents with periodontitis impact the subgingival colonization of their offspring.

Early acquisition of a pathogenic microbiota and the presence of dysbiosis in childhood is associated with susceptibility to and the familial aggregation of periodontitis. This longitudinal interventional case-control study aimed to evaluate the impact of parental periodontal disease on the acquisition of oral pathogens in their offspring. Subgingival plaque and clinical periodontal metrics were collected from 18 parents with a history of generalized aggressive periodontitis and their children (6-12 years of age), and 18 periodontally healthy parents and their parents at baseline and following professional oral prophylaxis. 16S rRNA amplicon sequencing revealed that parents were the primary source of the child's microbiome, affecting their microbial acquisition and diversity. Children of periodontitis parents were preferentially colonized by Filifactor alocis, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Streptococcus parasanguinis, Fusobacterium nucleatum and several species belonging to the genus Selenomonas even in the absence of periodontitis, and these species controlled inter-bacterial interactions. These pathogens also emerged as robust discriminators of the microbial signatures of children of parents with periodontitis. Plaque control did not modulate this pathogenic pattern, attesting to the microbiome's resistance to change once it has been established. This study highlights the critical role played by parental disease in microbial colonization patterns in their offspring and the early acquisition of periodontitis-related species and underscores the need for greater surveillance and preventive measures in families of periodontitis patients.

Glucose effect on Candida albicans biofilm during tissue invasion.

OBJECTIVE: To evaluate, in vitro, the effect of two glucose concentrations (0.1 mM and 1.0 mM, simulating glucose concentration in saliva of healthy and diabetic individuals) on Candida albicans biofilm grown on epithelial monolayer. MATERIAL AND METHODS: C. albicans was inoculated on epithelial monolayers supplemented with 0.1 mM, 1.0 mM or no glucose. Control groups without C. albicans were also evaluated. Tissue response was assessed through the production of Interleukin-1α, Interleukin-8, Interleukin-6, Interleukin-10 and tumor necrosis factor-α. The complex of monolayer and biofilms were evaluated by quantitative reverse transcription polymerase chain reaction for expression of E-cadherin (CDH1), Caspase-3 (CASP3), ß-defensin-1 (DEFB-1) and ß-defensin-3 (DEFB-3). The biofilm architecture was visualized by confocal laser scanning microscopy. RESULTS: The production of Interleukin-1α and Interleukin-8 were increased in the presence of C. albicans (p < 0.05). Glucose did not interfere in the release of any cytokine evaluated. C. albicans downregulated transcripts for CDH1 (p < 0.05). Glucose did not induce a significant change in CDH1, CASP3, DEFB-1 and DEFB-3 messenger RNA expression. The biofilms were more structured in the presence of glucose, but no difference in the diffusion of hyphae through the epithelial cells were observed. CONCLUSIONS: The data suggest that glucose concentration does not affect the behavior of C. albicans during tissue invasion and other mechanisms must be related to the greater susceptibility of diabetic individuals to candidiasis.

Isolation and characterization of a human cementocyte-like cell line, HCY-23.

Cementum is the mineralized tissue covering the tooth root that functions in tooth attachment and post-eruptive adjustment of tooth position. It has been reported to be highly similar to bone in several respects but remains poorly understood in terms of development and regeneration. Here, we investigate whether cementocytes, the residing cells in cellular cementum, have the potential to be protagonist in cementum homeostasis, responding to endocrine signals and directing local cementum metabolism. Cells from healthy erupted human teeth were isolated using sequential collagenase/EDTA digestions, and maintained in standard cell culture conditions. A cementocyte-like cell line was cloned (HCY-23, for human cementocyte clone 23), which presented a cementocyte compatible gene expression signature, including the expression of dentin matrix protein 1 ( DMP1 ), sclerostin ( SOST ), and E11/gp38/podoplanin ( E11 ). In contrast, these cells did not express the odontoblast/dentin marker dentin sialoprotein ( DSPP ). HCY-23 cells produced mineral-like nodules in vitro under differentiation conditions, and were highly responsive to inorganic phosphate (Pi). Within the limits of the present study, it can be concluded that cementocytes are phosphate-responsive cells, and have the potential do play a key role in periodontal homeostasis and regeneration.

Isolation and characterization of a human cementocyte-like cell line, HCY-23

Abstract Cementum is the mineralized tissue covering the tooth root that functions in tooth attachment and post-eruptive adjustment of tooth position. It has been reported to be highly similar to bone in several respects but remains poorly understood in terms of development and regeneration. Here, we investigate whether cementocytes, the residing cells in cellular cementum, have the potential to be protagonist in cementum homeostasis, responding to endocrine signals and directing local cementum metabolism. Cells from healthy erupted human teeth were isolated using sequential collagenase/EDTA digestions, and maintained in standard cell culture conditions. A cementocyte-like cell line was cloned (HCY-23, for human cementocyte clone 23), which presented a cementocyte compatible gene expression signature, including the expression of dentin matrix protein 1 ( DMP1 ), sclerostin ( SOST ), and E11/gp38/podoplanin ( E11 ). In contrast, these cells did not express the odontoblast/dentin marker dentin sialoprotein ( DSPP ). HCY-23 cells produced mineral-like nodules in vitro under differentiation conditions, and were highly responsive to inorganic phosphate (Pi). Within the limits of the present study, it can be concluded that cementocytes are phosphate-responsive cells, and have the potential do play a key role in periodontal homeostasis and regeneration.

Transcriptome of healthy gingival tissue from edentulous sites in patients with a history of generalized aggressive periodontitis.

BACKGROUND: This study evaluates the transcriptome of healthy gingival tissue from edentulous sites in patients with a history of generalized aggressive periodontitis (GAgP), chronic periodontitis (CP), and in patients with no history of periodontitis (H), using microarray and quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. METHODS: Healthy gingival tissue from edentulous sites was taken from patients from the GAgP (n = 12), CP (n = 12), and H (n = 12) groups. Initially, total RNA from four tissue samples per group was used in transcriptomic microarray analysis. Differential gene expression (fold-change), gene ontology (GO; biologic process), and pathway analyses were performed. Genes that were differentially expressed and showing a significant role on altered pathways were validated by qRT-PCR analysis on 12 samples per group. RESULTS: In total, 270 probe sets and 50 GO groups were differentially expressed (upregulated or downregulated) between GAgP and H. Natural killer cell receptors and other genes related to the immune system were upregulated in GAgP, whereas genes with functions in neural processes and in proliferation/differentiation of keratinocytes were underexpressed. There were 220 probe sets and 75 GO groups that were differentially expressed when comparing CP and GAgP. CP was characterized by increased expression of genes related to responses to external stimuli and an underexpression of immune system-related genes. qRT-PCR analysis confirmed microarray results, that killer cell immunoglobulin (Ig)-like receptor, two Ig domains and long cytoplasmic tail 4; interleukin-6; and selectin E were more highly expressed in patients from the GAgP group compared with the CP and H groups. CONCLUSION: This study demonstrates differences in the transcriptome of healthy gingival tissue from edentulous sites in patients with GAgP compared with patients from H or CP groups.

Mesenchymal stem cells in periodontics: new perspectives / Células mesenquimais indiferenciadas em periodontia: novas perspectivas

ABSTRACT Tissue engineering is a contemporary field of science, which aims to create conditions based on principles of cell and molecular biology, bioengineering and biomaterials to regenerate tissues. Mesenchymal stem cells present high proliferation rates and are able to differentiate into multilineages under certain conditions, suggesting that they have great potential to act in regeneration field. Tooth derived stem cells are a suitable alternative source of mesenchymal cells once they are easily accessible and have poor morbidity to the donor. Studies showed that they have been isolated and characterized from diverse tissues such as dental pulp, exfoliated deciduous teeth, periodontal ligament, gingiva, dental follicle and apical papilla. However studies show that there is heterogeneity among these populations and there is no standard method to select the most appropriate tooth derived stem cells for regenerative procedures. The aim of this review is to present the current perspective of the multiple types of tooth-derived stem cells and to discuss the basis for their use in periodontal tissue engineering.

RESUMO A engenharia de tecidos é um campo contemporâneo da ciência, que visa criar condições baseadas em princípios de biologia celular e molecular, bioengenharia e biomateriais para regenerar tecidos. As células tronco mesenquimais apresentam altas taxas de proliferação e são capazes de se diferenciar, sob certas condições, em multi-linhagens, sugerindo que elas têm grande potencial para atuar no campo da regeneração. As células tronco derivadas de tecidos dentais são uma fonte alternativa adequada de células mesenquimais uma vez que são de fácil acesso e têm baixa morbidade para o doador. Estudos demonstraram que elas já foram isoladas e caracterizadas a partir de diversos tecidos tais como polpa dentária, dentes decíduos esfoliados, ligamento periodontal, gengiva, folículo dental e papila apical. Entretanto, os estudos demonstram que há heterogeneidade entre essas populações e não existe um método padrão para selecionar as células-tronco dentais mais apropriadas para procedimentos regenerativos. O objetivo desta revisão é apresentar o conhecimento atual dos vários tipos de células-tronco derivadas de dentes e discutir as novas perspectivas para seu uso na engenharia de tecidos periodontais.

Doença peri-implantar: Abordagens contemporâneas / Peri-implant disease: contemporary approaches

O uso de implantes dentários é considerado uma revolução na Odontologia moderna. Entretanto, um dos grandes desafios encontrados na Implantodontia é o processo de reabsorção óssea ao redor dos implantes, após sua colocação ou durante o uso. Esta revisão teve por objetivo discutir alguns avanços nas pesquisas científicas que utilizam parâmetros clínicos para classificação da doença peri-implantar. Diversos estudos na literatura demonstram que essas ferramentas podem promover uma melhor compreensão, tanto do cirurgião-dentista quanto dos pacientes que necessitam da utilização desses.

The use of dental implants is considered a revolution in modern dentistry. However, the great challenges found at implantodontology is the process of bone resorption around implants after placement or during use. This review aims to discuss some advances in scientific research that use clinical parameters to classify peri-implant disease. Several studies in the literature demonstrate these tools can promote a better understanding for both dental surgeons and patients in need of this.

Cemento dental: aspectos atuais de interesse para o clínico / Dental cementum: current aspects to the clinicians

Embora tenha havido avanço no entendimento da homeostase do cemento dental, o papel deste tecido e sua biologia permanecem não completamente elucidados. Este estudo buscou fornecer informações sobre os conhecimentos mais recente relacionados à biologia do cemento dental, com o objetivo de discutir o papel exercido por este tecido em condições não fisiológicas nos tecidos periodontais. Devido aos avanços na exploração do tecido ósseo, que compartilha diversas características similares, a pesquisa abrangente sobre o cemento dental tem sido encorajada, a fim de esclarecer a função completa deste tecido na homeostase periodontal e regeneração. Desta forma, no presente trabalho, sempre que possível será feito um paralelo entre osso alveolar e cemento dental. O desenvolvimento de metodologias e técnicas celulares e moleculares avançadas possibilitou um melhor entendimento do comportamento do cemento em situações diversas, como quando em situações patológicas, como a doença periodontal, e até mesmo frente à regeneração tecidual. Ademais, estudos clínicos e em modelo animal demonstraram resultados em relação à formação de cemento em abordagens regenerativas. No entanto, sugere-se que estudos posteriores possam contribuir para um melhor conhecimento sobre o cemento e o perfil celular dos cementoblastos e cementócitos, bem como suas interações para fornecer novos insights para o desenvolvimento de terapias eficientes e mais previsíveis para regeneração dos tecidos periodontais. Apesar dos avanços dos estudos clínicos e laboratoriais, pôde-se concluir que inúmeras questões referentes à biologia do cemento permanecem não esclarecidas.

Although some progress has been made to understand dental cementum homeostasis, its role and biology remains not completely elucidated. This study aimed to provide information on the recent knowledge related to the dental cementum biology, in order to discuss the role of this tissue in physiological and non-physiological conditions in the periodontal tissues. Due to advances in the exploration of bone tissue, which shares several similar features, comprehensive research on dental cementum has been encouraged in order to clarify the complete function of this tissue in periodontal homeostasis and regenerative approach. Novel methodologies and advanced cellular and molecular techniques provided better understanding of cementum in different circumstances, as pathological situations such as periodontal disease and even tissue regeneration. In addition, clinical and animal model designs show positive outcomes to cementum formation in regenerative approaches, however, it is suggested that further studies may contribute to better understand cementum tissue and cementoblasts and cementocytes profile, as well as their interactions, providing new insights to develop efficient and more predictable therapies for periodontal tissue regeneration. Despite advances in clinical and laboratory studies, it can be concluded that many questions regarding the cementum biology remain unclear.

Regeneração óssea guiada no tratamento de peri-implantite: dois anos de acompanhamento clínico / Guided bone regeneration in the treatment of peri-implantitis: 2 years of clinical follow-up

A peri-implantite é caracterizada pelo processo inflamatório ao redor de um implante, que inclui inflamação do tecido mole e perda progressiva de suporte ósseo. O foco do seu tratamento está no controle da infecção bacteriana, através da eliminação do biofilme da superfície do implante e, quando possível, na regeneração do osso perdido. Contudo, atualmente não existe evidência suficiente na literatura para indicar qual abordagem terapêutica é superior no tratamento da peri-implantite a longo prazo. Dessa forma, o objetivo do presente relato de caso clínico foi reportar os resultados a longo prazo do tratamento de um caso de peri-implantite, com a combinação de acesso cirúrgico para descontaminação da superfície do implante, uso adjunto de solução de tetraciclina (50 mg/ml) e procedimento de regeneração óssea guiada, utilizando enxerto xenógeno e membrana reabsorvível de colágeno. Aos dois anos de acompanhamento pós-operatório, observou-se uma melhora clínica significativa, com redução da profundidade de sondagem, ganho de inserção clínica e preenchimento ósseo radiográfico do defeito peri-implantar. Pôde-se observar que o acesso cirúrgico associado à regeneração óssea guiada é uma alternativa viável para o tratamento de lesões de peri-implantite.

Peri-implantitis is an inflammatory process around an implant, which includes soft tissue inflammation and progressive bone loss. Treatment aims to control the bacterial infection through elimination of the established biofilm from the implant surface, and if possible, the regeneration of the lost bone. However, currently there is not sufficient evidence in the literature supporting which therapeutic approach is most suitable for the treatment of peri-implantits at long-term follow-up. Thus, the aim of this case demonstrate was to report the results of a peri-implantitis treatment at long-term follow-up, with the combination of surgical access for decontamination of the implant surface, with adjunctive use of tetracycline solution (50 mg/ml) and guided bone regeneration procedure using xenogeneic graft and resorbable collagen membrane. A significant clinical improvement was observed at 2 years of follow-up, with reduced probing depth, clinical attachment gain and radiographic bone fill in the peri-implant defect. It can be concluded that the surgical access associated with guided bone regeneration is a viable option for the treatment of peri-implant lesions

Full-mouth ultrasonic debridement associated with povidone iodine rinsing in GAgP treatment: a randomised clinical trial.

OBJECTIVE: This study evaluated the clinical, immunological and microbiological results of full-mouth ultrasonic debridement (FMUD) with 10 % povidone iodine (PVPI) as the cooling liquid in the treatment of generalised aggressive periodontitis (GAgP). MATERIAL AND METHODS: Twenty-eight patients presenting GAgP were randomly assigned to one of the following groups for evaluation: FMUD + SS (n = 14)--single session of FMUD with 0.9 % saline solution as cooling agent and FMUD + PVPI (n = 14)--single session of FMUD with PVPI solution as cooling agent. Probing depth (PD), relative clinical attachment level (RCAL), relative position of gingival margin, plaque index (FMPI) and bleeding score (FMBS), immunological (interleukin-10 and interleukin-1ß concentrations in gingival crevicular fluid) and microbiological (Aa and Pg amounts) parameters were evaluated at baseline, first, third and sixth months after treatment. RESULTS: The two groups presented reduction of FMPI and FMBS and had statistically significant PD reductions, RCAL gains and gingival recession (p < 0.05). Both therapies reduced Pg levels in deep and in moderate pockets (p < 0.05). FMUD + PVPI reduced Aa levels in deep pockets. However, no inter-group differences in clinical, immunological and microbiological parameters were observed (p > 0.05). CONCLUSIONS: It could be concluded that 10 % PVPI used as an irrigant solution in FMUD decreased Aa levels in deep pockets but had no additional benefits when compared with saline solution irrigation in terms of clinical, microbiological and immunological results. CLINICAL RELEVANCE: The FMUD is a valid option for the treatment of GAgP, but the use of 10 % PVPI did not improve the results of the periodontal therapy.

Retalho semilunar e proteína derivada da matriz do esmalte em recessão gengival / Semilunar flap associated and enamel matrix derivative in gingival recession

A recessão gengival é caracterizada por um posicionamento apical da margem gengival em relação à junção cemento-esmalte. Dentre as técnicas propostas para o tratamento desta condição, destaca-se o retalho semilunar posicionado coronariamente (RSPC). Associação de técnicas de recobrimento radicular com o uso de gel contendo proteínas derivadas da matriz do esmalte tem sido abordada ultimamente, com o intuito de melhorar os resultados clínicos. Portanto, o objetivo foi relatar a utilização do RSPC para tratamento de recessões gengivais, com associação à proteína derivada da matriz do esmalte.

Gingival recession is characterized by an apical positioning of the gingival margin in relation to the cement-enamel junction (American Academy of Periodontology – AAP, 2001). Among the techniques proposed for the treatment of this condition, there is the semilunar coronally positioned flap (SCPF) – Tarnow, 1986. Combination of techniques root coverage with the use of gel containing proteins derived from enamel matrix has recently been approached in order to improving clinical outcomes. Therefore, the aim will be to report the use of the SCPF for treatment of gingival recessions, in association with the enamel matrix derivative.

Proteomic analysis of human dental cementum and alveolar bone.

Dental cementum (DC) is a bone-like tissue covering the tooth root and responsible for attaching the tooth to the alveolar bone (AB) via the periodontal ligament (PDL). Studies have unsuccessfully tried to identify factors specific to DC versus AB, in an effort to better understand DC development and regeneration. The present study aimed to use matched human DC and AB samples (n=7) to generate their proteomes for comparative analysis. Bone samples were harvested from tooth extraction sites, whereas DC samples were obtained from the apical root portion of extracted third molars. Samples were denatured, followed by protein extraction reduction, alkylation and digestion for analysis by nanoAcquity HPLC system and LTQ-FT Ultra. Data analysis demonstrated that a total of 318 proteins were identified in AB and DC. In addition to shared proteins between these tissues, 105 and 83 proteins exclusive to AB or DC were identified, respectively. This is the first report analyzing the proteomic composition of human DC matrix and identifying putative unique and enriched proteins in comparison to alveolar bone. These findings may provide novel insights into developmental differences between DC and AB, and identify candidate biomarkers that may lead to more efficient and predictable therapies for periodontal regeneration. BIOLOGICAL SIGNIFICANCE: Periodontal disease is a highly prevalent disease affecting the world population, which involves breakdown of the tooth supporting tissues, the periodontal ligament, alveolar bone, and dental cementum. The lack of knowledge on specific factors that differentiate alveolar bone and dental cementum limits the development of more efficient and predictable reconstructive therapies. In order to better understand cementum development and potentially identify factors to improve therapeutic outcomes, we took the unique approach of using matched patient samples of dental cementum and alveolar bone to generate and compare a proteome list for each tissue. A potential biomarker for dental cementum was identified, superoxide dismutase 3 (SOD3), which is found in cementum and cementum-associated cells in mouse, pig, and human tissues. These findings may provide novel insights into developmental differences between alveolar bone and dental cementum, and represent the basis for improved and more predictable therapies.

Curcumina como promissor agente fotossensibilizador para uso em periodontia / Curcumin as a promising photosensitizing agent for use in Periodontics

A terapia fotodinâmica (TFD) tem sido utilizada com sucesso em Odontologia e, atualmente, tem sido proposta como alternativa dentro da terapia periodontal. Não existe, porém, um consenso sobre o melhor protocolo clínico de TFD em Periodontia, sendo necessárias pesquisas de novos fotossensibilizadores com finalidade de potencializar o efeito antimicrobiano da TFD sobre o biofilme periodontal e, consequentemente, sobre os parâmetros clínicos periodontais. Dessa forma, sugere-se, nesta revisão da literatura, a curcumina como uma potencial droga fotossensibilizadora para uso em Periodontia. Porém, são necessários estudos que validem um protocolo para seu uso clínico e confirmem sua eficácia no controle das doenças periodontais.

Estado atual da clorexidina na terapia periodontal / Current status of chlorhexidine in periodontal therapy

A clorexidina é uma bisbiguanida de amplo espectro que age em bactérias gram-positivas, gram-negativas, alguns vírus, leveduras e fungos. É considerada o agente químico gold standard no controle do biofilme supragengival e da inflamação e vem sendo utilizada como terapia coadjuvante em Periodontia desde a década de 1970. A literatura ao longo desse tempo vem propondo indicações, protocolos, formulações e concentrações distintas, podendo gerar dúvidas quanto a sua prescrição. Esta revisão teve como objetivo abordar a literatura científica com intuito de auxiliar o decision making do periodontista quanto ao uso da clorexidina frente ao tipo de doença, perfil sistêmico e limitações de cada paciente.

Diagnóstico e tratamento de periodontite agressiva / Diagnosis and treatment in aggressive periodontitis

A periodontite agressiva é uma doença que ainda se apresenta como desafio para o diagnóstico e para o tratamento. Frequentemente, acomete pessoas saudáveis, tem forte correlação familiar e produz rápida perda de inserção. Entretanto, as características clínicas não são suficientes para fechar o diagnóstico. A presença de uma microbiota patogênica é fundamental para o início e a progressão da doença. A biodiversidade da microflora subgengival é bastante grande, e uma grande parte ainda permanece desconhecida. O perfil genético também pode estar diretamente relacionado à destruição periodontal, pela alteração de funções celulares relativas ao sistema imune-inflamatório, causadas por mutações ou polimorfismos. Embora a PA seja uma doença multifatorial de difícil compreensão dos fatores etiológicos, o tratamento de escolha para a PA é a terapia mecânica, que demonstrou melhora significativa dos parâmetros clínicos. O uso de antimicrobianos como auxiliar no tratamento tem tentado potencializar os resultados clínicos da terapia mecânica. O objetivo deste artigo foi pontuar as características clínicas, microbiológicas e imunológicas que possam auxiliar o diagnóstico da periodontite agressiva, bem como uma revisão dos protocolos de tratamento periodontal mais recentemente avaliados, permitindo um tratamento focado em características específicas dessa condição patológica.

Peri-implant reconstruction using autologous periosteum-derived cells and guided bone regeneration.

AIM: This investigation evaluated the bone healing in peri-implant defects treated with periosteum-derived cells (PCs) and guided bone regeneration (GBR). MATERIAL AND METHODS: PCs were harvested from six beagle dogs and characterized in vitro with regard to their osteogenic properties. The animals were subjected to teeth extraction in the mandible, and after 3 months of healing, implant sites were drilled, bone dehiscences were created and implants were placed. Dehiscences were randomly assigned to: PCs+GBR, GBR, PCs and non-treated defects. After 3 months, the implants/adjacent tissues were processed. Bone-to-implant contact (BIC) bone fill (BF) within implant threads, and bone area (BA) in a zone lateral to the implant were obtained. RESULTS: In vitro analyses confirmed the osteogenic potential of PCs. Histometrically, no statistically significant differences were observed among the PCs+GBR, GBR and PCs groups for both BF and BIC (p>0.05), whereas these groups showed statistically higher values, as compared with the non-treated group (p<0.05). With respect to BA, the PCs+GBR and GBR groups presented significantly higher means, as compared with the PCs and non-treated groups (p<0.05). CONCLUSION: Although successful outcomes have been promoted by using the combined approach, PCs in conjunction with membranes did not provide additional benefit during peri-implant bone regeneration, when compared with the therapeutic approaches used alone.

Cigarette smoke inhalation modulates gene expression in sites of bone healing: a study in rats.

OBJECTIVE: The aim of this study was to assess the effect of cigarette smoke inhalation (CSI) on gene expression in alveolar bone healing sites. STUDY DESIGN: Wistar rats were randomly assigned to the groups: control [animals not exposed to CSI (n = 20)] and test [animals exposed to CSI, starting 3 days before teeth extraction and maintained until killing them (n = 20)]. First mandibular molars were bilaterally extracted, and the expression of alkaline phosphatase, bone morphogenetic protein (BMP) 2 and 7, receptor activator of nuclear factor κB ligand, osteoprotegerin, and d2 isoform of vacuolar adenosine triphosphatase V(0) domain were assessed by quantitative polymerase chain reaction in the newly formed tissue in the sockets. RESULTS: Overall, data analysis demonstrated that CSI significantly affected the expression pattern of all of the studied genes except BMP-7. CONCLUSION: The expression of key genes for bone healing may be affected by CSI in tooth extraction sites.

Engenharia tecidual: um novo paradigma da regeneração periodontal / Tissue engineering: a new paradigm for periodontal regeneration

O periodonto é uma complexa estrutra constituída por diferentes tecidos - tecido epitelial, tecido conjuntivo, tecido cementário e tecido ósseo. A doença periodontal é um processo inflamatório nos tecidos periodontals de suporte e proteção, resultando em destruição de osso e ligamento periodontal, formação de bolsas e recessões gengivais. Os estudos existentes na literatura, até o presente momento, têm demonstrado que, embora seja possível modificar os eventos de cura de várias maneiras, a regeneração periodontal completa e desejada dos defeitos periodontals, ainda é um objetivo difícil de ser alcançado. O estudo da engenharia tecidual tem sugerido a possibilidade de uso da terapia celular como alternativa para as técnicas regenerativas até então utilizadas. O conhecimento dos conceitos básicos de regeneração periodontal e dos princípios necessários para o sucesso da engenharia tecidual, bem como a compreensão do seu princípio biológico tornam-se necessários para o entendimento deste novo paradigma da terapia periodontal regenerativa. Sendo assim, o objetivo deste artigo é discutir o potencial das células do ligamento periodontal quando utilizadas com o propósito de promover a regeneração periodontal.