Effects of a full-mouth disinfection protocol on the treatment of type-2 diabetic and non-diabetic subjects with mild-to-moderate periodontitis: one-year clinical outcomes.

OBJECTIVES: This study compared the clinical effects of a full-mouth disinfection (FMD) protocol for the treatment of mild-to-moderate periodontitis in type 2 diabetic and non-diabetic subjects for up to 1 year. Secondary aim was to evaluate the effects of this therapy on the salivary levels of periodontal pathogens between diabetics and non-diabetics. MATERIAL AND METHODS: Twenty-six type 2 diabetic subjects and 28 non-diabetic subjects with mild-to-moderate periodontitis received full-mouth scaling and root planing within 24 h, application of chlorhexidine digluconate (CHX) gel in pockets and tongue plus CHX rinses for 14 days. Clinical monitoring was performed at baseline, 3, 6, and 12 months post-therapy. Salivary levels of red complex bacterial species were evaluated at baseline, 6, and 12 months post-therapy by qPCR. RESULTS: Intention-to-treat analyses were performed for seven diabetics and three non-diabetics that did not return for the 12-month evaluation. Most clinical parameters improved significantly at 3, 6, and 12 months post-therapies for both groups (p < 0.05). Overall, there were no significant differences in clinical parameters between groups after therapy (p > 0.05). At 1 year, 39.3% and 50.0% of the non-diabetic and diabetic subjects, respectively, achieved the desired clinical endpoint for treatment (≤ 4 sites with probing depth ≥ 5 mm) (primary outcome variable) (p > 0.05). FMD did not promote changes in the salivary levels of pathogens in either of the groups (p > 0.05). Levels of T. forsythia were lower in diabetic than in non-diabetic subjects at 6 months post-therapy (p < 0.05). CONCLUSIONS: Type 2 diabetic subjects and systemically healthy subjects with mild-to-moderate periodontitis responded similarly to the proposed FMD protocol for up to 1 year. CLINICAL RELEVANCE: There is a general thought that diabetics do not answer as well as non-diabetics to periodontal treatments. However, this study showed that diabetics and non-diabetics respond equally to the FMD protocol. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02643771.

Long-term periodontal tissue outcome in regenerated infrabony and furcation defects: a systematic review.

OBJECTIVES: This study aimed to systematically evaluate the long-term results of periodontal tissues in regenerated infrabony and furcation defects. MATERIAL AND METHODS: A search of the Medline database was performed (1960 to 2012), complimented by an additional hand search. For inclusion in the review, clinical trials had to include the long-term evaluation of infrabony and furcation defects submitted to periodontal regeneration for up to 3 years of follow-up. Changes in clinical attachment level (CAL) from pre-surgery, at the first post-surgical, and final evaluations were used to analyze the effects of regenerative treatments over time. RESULTS: A total of 866 articles were found using the descriptors employed. Of these, 216 papers were selected for abstract reading by two evaluators. One hundred and eighty-nine were excluded for not fulfilling the eligibility criteria. Twenty-seven papers were selected for the analysis of the full texts, and 13 were excluded. Two studies were included after a manual search. Finally, 16 papers were selected for the present review. CONCLUSIONS: Regenerative techniques for the treatment of infrabony and furcation defects resulted in improved CAL during long-term follow-up periods, even when attachment losses occurred during this period. This improvement should be carefully evaluated with regard to its clinical relevance for dental longevity. CLINICAL RELEVANCE: The improvement in clinical attachment level achieved by regenerative techniques with biomaterials demonstrated satisfactory results over the long-term. However, regenerative techniques still present different success rates with regard to gain in clinical attachment level.

Avaliação clínica, histológica e imunológica de enxertos ósseos alógenos fresco-congelados utilizados como técnica na preservação de rebordo alveolar pós-extração / Preservation of alveolar bone in extraction sockets using fresh-frozen bone allograft: a clinical, histological and immunological study

O osso alógeno fresco-congelado (FFBA, do inglês fresh-frozen bone allograft) é uma alternativa para os procedimentos cirúrgicos de enxerto ósseo, principalmente na preparação do rebordo alveolar para a instalação de implantes osseointegráveis. No entanto, existem alguns paradigmas que envolvem a relação entre resposta do sistema imunológico à aloantígenos presentes no enxerto e o seu comportamento clínico. Procurando entender essa relação, o FFBA foi avaliado como enxerto para preservar o rebordo alveolar pós-extração. Os resultados mostraram que embora tenha ocorrido uma redução estatisticamente significante na altura, espessura e volume do rebordo entre a avaliação inicial e final, essa redução não foi clinicamente significante, permitindo a instalação de implantes osseointegráveis. Em adição, as análises histológicas sugerem um bom comportamento do enxerto, com ausência de reação do tipo corpo estranho e formação de novo osso em todos os sítios analisados. Ao analisar o comportamento da resposta imune, os resultados mostraram que a injeção intradérmica de aloantígenos presentes no FFBA, não induziu uma reação de hipersensibilidade tardia nos pacientes após 4 meses do enxerto. Além disso, os monócitos do sangue periférico (PBMCs) dos pacientes não proliferaram frente aos aloantígenos in vitro. No entanto, os dados também demonstraram que os aloantígenos aumentam a produção de IL-2 e IFN-, mas não alteram a produção de IL-4 e IL-10, por PBMCs dos pacientes. Ao avaliar a relação entre a produção dessas citocinas e o comportamento clínico do enxerto, os dados mostram que existe uma correlação estatisticamente significante entre a produção de IL-2 in vitro e a redução (em %) da altura do rebordo alveolar, embora essa redução não tenha sido clinicamente significante. De fato, a presença de aloantígenos no FFBA não é suficiente para sua contraindicação como material de enxertia.

The fresh-frozen bone allograft (FFBA) is an alternative to surgical procedures of bone grafts, mainly in the preservation of alveolar ridge prior the installation of osseointegrated implants. However there are paradigms that surround the relation between immune response to alloantigens present inside the graft and the clinical response of the graft. An attempt to understand this relationship, the FFBA was evaluated as a graft to preserve the alveolar ridge post-extraction. The results show a statistically significant reduction in height, thickness and volume of the ridge between the initial and final examination, however this reduction was not clinically significant. The ridge preservation allowed implant installation and osseointegration. In addition, histologic analysis suggests a good performance of the graft with no foreign body reaction and formation of new bone at all sites. In analyzing the behavior immune response, the results showed that stimulation with alloantigens present in bone allograft induced no delayed hypersensitivity reaction in vivo. Additionally, periphery blood mononuclear cells (PBMC) from patients no proliferate in response to alloantigens in vitro. However, the data also demonstrated that the alloantigens increase IL-2 and IFN- production, but no IL-4 and IL-10 production, by PBMCs from patients. When evaluate the relation between the cytokines production and clinical parameters, the results demonstrate that there statistically significant correlation between IL-2 production in vitro and ridge height changes (%), although this clinical parameter is not clinically significant. In fact, the alloantigens in FFBA are not sufficient for its contraindications as grafting material.

Absence of TLR2 influences survival of neutrophils after infection with Candida albicans.

Candida albicans is an opportunistic pathogen, which causes local and/or disseminated diseases in immunosuppressed humans. Phagocytic cells play a critical role in the immune response against C. albicans. Toll like receptors (TLR) are important in the identification of invading microorganisms and in the regulation of neutrophil survival. TLR2 has been shown to participate in the response against pathogenic yeasts and to increase the functional life span of neutrophils. In view of these observations, we studied the involvement of TLR2 in neutrophil function after C. albicans infection. The absence of TLR2 resulted in lower chemotaxis of neutrophils to the site of infection. This in turn was associated with lower levels of chemokines from neutrophils, facilitating the dissemination of the pathogen to the lymph nodes and spleen. A high frequency of apoptotic neutrophils and macrophages in the inflammatory exudates from TLR2(-/-) mice was found. In addition, the phagocytic activity of neutrophils and macrophages, nitric oxide production and myeloperoxidase activity were diminished in cells from TLR2(-/-) mice. Together, these data demonstrate the importance of TLR2 signals for neutrophils activation and survival after C. albicans infection.

Inhibitory signals mediated by programmed death-1 are involved with T-cell function in chronic periodontitis.

BACKGROUND: Inhibitory signals mediated via molecules such as programmed death-1 (PD-1) play a critical role in downmodulating immune responses and maintaining peripheral tolerance. We investigated the involvement of cytokines and PD-1 engagement in mediating the T-cell unresponsiveness to bacterial and ubiquitous antigens in periodontal diseases. METHODS: Gingival and peripheral blood samples from healthy individuals and patients with chronic periodontitis were collected and used for the subsequent assays. Leukocytes in the lesion site and blood were evaluated using flow cytometry. The production of interferon-gamma, interleukin-10, and transforming growth factor-beta proteins was evaluated by enzyme-linked immunosorbent assay (ELISA), and the presence of PD-1+ cells in the inflamed gingiva was confirmed by immunofluorescence confocal microscopy for CD4 and PD-1 colocalization. RESULTS: T cells from patients with chronic periodontitis proliferated poorly in response to Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) antigen. T-cell unresponsiveness was not associated with imbalanced cytokine production. However, T cells from patients with chronic periodontitis expressed significantly higher levels of PD-1 either upon isolation or after culture with antigens. Moreover, PD-1 blocking did not result in significant T-cell proliferation in cells cultured with phytohemagglutinin or bacterial antigens. The blockade of PD-1 resulted in the increased production of IFN-gamma. In addition, CD4+ and CD8+ T cells expressing PD-1 accumulated in lesions with chronic periodontitis. CONCLUSION: These data show that PD-1 engagement could be involved in the modulation of IFN-gamma production by T cells in patients with chronic periodontitis.

Evaluation of the cytocompatibility of mixed bovine bone.

Treatment of bovine bone with peroxides and chaotropic agents aims to obtain an acellular bone matrix that is able to maintain the collagen-apatite complex and a higher mechanical resistance, a mixed biomaterial hereby named mixed bovine bone (MBB). The purpose of this study was to evaluate the cytocompatibility of MBB and cell-MBB interaction. Cell morphology, number of viable cells, ability to reduce methyltetrazolium and to incorporate neutral red upon exposure to different concentrations of the hydrosoluble extract of MBB were assessed in Balb-c 3T3 cells according to ISO 10993-5 standard. The interaction between cells and MBB surface was evaluated by scanning electron microscopy. The water-soluble MBB extracts were cytotoxic and led to cell death possibly due to its effect on mitochondrial function and membrane permeability. Cells plated directly onto the MBB did not survive, although after dialysis and material conditioning in DMEM + 10% FCS, the cells adhered and proliferated onto the material. It may be concluded that, in vitro, water-soluble MBB extracts were cytotoxic. Nevertheless, MBB cytotoxic effect was reverted by dialysis resulting in a material that is suitable for cell based-therapy in the bioengineering field.

Evaluation of the cytocompatibility of mixed bovine bone

Treatment of bovine bone with peroxides and chaotropic agents aims to obtain an acellular bone matrix that is able to maintain the collagen-apatite complex and a higher mechanical resistance, a mixed biomaterial hereby named mixed bovine bone (MBB). The purpose of this study was to evaluate the cytocompatibility of MBB and cell-MBB interaction. Cell morphology, number of viable cells, ability to reduce methyltetrazolium and to incorporate neutral red upon exposure to different concentrations of the hydrosoluble extract of MBB were assessed in Balb-c 3T3 cells according to ISO 10993-5 standard. The interaction between cells and MBB surface was evaluated by scanning electron microscopy. The water-soluble MBB extracts were cytotoxic and led to cell death possibly due to its effect on mitochondrial function and membrane permeability. Cells plated directly onto the MBB did not survive, although after dialysis and material conditioning in DMEM + 10 percent FCS, the cells adhered and proliferated onto the material. It may be concluded that, in vitro, water-soluble MBB extracts were cytotoxic. Nevertheless, MBB cytotoxic effect was reverted by dialysis resulting in a material that is suitable for cell based-therapy in the bioengineering field.

O tratamento do osso bovino com peróxidos e agentes caotrópicos visa à obtenção de uma matriz óssea acelular, com manutenção do complexo colágeno-apatita e maior resistência mecânica, denominada osso bovino misto (OBM). O objetivo desse estudo foi avaliar a citocompatitiblidade do osso bovino misto e a interação célula-OBM. Células Balb-c 3T3 foram tratadas com diferentes concentrações do extrato hidrossolúvel do OBM (0,1g por mililitro de meio de cultura sem soro). Foram avaliadas a morfologia e número de células, a capacidade de redução do metil tetrazol e a incorporação de vermelho neutro, de acordo com o padrão ISO 10993-5. A interação células-OBM foi estudada por microscopia eletrônica de varredura. Os extratos hidrosolúveis do OBM levaram à morte celular, possivelmente devido à redução da função mitocondrial e aumento da permeabilidade de membrana. Células plaqueadas diretamente sobre o OBM não sobreviveram. Entretanto, após diálise e condicionamento com DMEM +10 por cento de soro fetal bovino, as células aderiram e proliferaram sobre o material. Com base nos resultados obtidos, concluiu-se que o OBM é citotóxico. A citotoxicidade foi revertida por diálise resultando em um material adequado para terapia celular no campo da bioengenharia.