Avaliação do comportamento das fibras colágenas periodontais durante a progressão da periodontite experimental em ratos / Evaluation of the behaviour of periodontal collagen fibers during the progression of experimental periodontitis in rats

Introdução: A periodontite é uma doença infecto-inflamatória, resultante da disbiose microbiana e da resposta do hospedeiro, que leva à destruição dos tecidos de suporte dentário, inclusive das fibras colágenas periodontais, podendo culminar na perda do elemento dental. Objetivo: Avaliar o comportamento das fibras colágenas periodontais durante a progressão da periodontite experimental induzida em ratos. Material e método: Doze ratos Wistar foram distribuídos nos grupos: Controle (C), Periodontite Experimental 14-dias (PE-14d), Periodontite Experimental 21-dias (PE-21d) e Periodontite Experimental 42-dias (PE-42d). No dia 0, os animais do grupo C foram eutanasiados. Neste mesmo dia, os animais remanescentes foram submetidos à instalação de uma ligadura de algodão ao redor do primeiro molar inferior esquerdo para indução da periodontite experimental. Tais animais foram eutanasiados aos 14 (PE-14d), 21 (PE-21d) e 42 (PE-42d) dias após a instalação da ligadura. Executou-se o processamento histológico das hemimandíbulas e as secções foram submetidas à reação histoquímica pelo vermelho picro-sirius. A análise qualitativa descritiva foi realizada sob microscopia de luz polarizada, na região de furca dental, evidenciando as fibras do ligamento periodontal. Resultado: O grupo C exibiu feixes espessos e orientados de fibras colágenas maduras, condizentes com aspecto de normalidade. Os grupos com periodontite experimental exibiram desestruturação tecidual severa, com fibras colágenas imaturas e de menor espessura, sendo tais condições mais exacerbadas nos grupos PE-14d e PE-21d. Conclusão: As fases iniciais da periodontite apresentam caráter agudo e, portanto, resultam na rápida destruição dos tecidos periodontais de suporte, prejudicando potencialmente a fibrilogênese e a reestruturação do colágeno no ligamento periodontal.

Introduction: Periodontitis is an infectious-inflammatory disease resulting from microbial dysbiosis and host response that leads to the destruction of tooth support tissues, including periodontal collagen fibers, which may culminate in tooth loss. Objective: To evaluate the behavior of periodontal collagen fibers during the progression of induced experimental periodontitis in rats. Material and method: Twelve Wistar rats were distributed into groups: Control (C), 14-days Experimental Periodontitis (PE-14d), 21-days Experimental Periodontitis (PE-21d) and 42-days Experimental Periodontitis (PE-42d). At day 0, the animals of group C were euthanized. At the same day, the remaining animals were submitted to the installation of a cotton ligature around the lower left first molar for the induction of experimental periodontitis. The animals were euthanized at 14 (PE-14d), 21 (PE-21d) and 42 (PE-42d) days after the installation of ligature. Histological processing of the hemi-mandibles was performed and the sections underwent histochemical reaction using picro-sirius red. The descriptive qualitative analysis was performed under polarized light microscopy, in the dental furcation region, evidencing the fibers of the periodontal ligament. Result: Group C exhibited thick and oriented bundles of mature collagen fibers, consistent with a normal appearance. The groups with experimental periodontitis exhibited severe tissue disruption, with immature and thinner collagen fibers, with such conditions being more exacerbated in the PE-14d and PE-21d groups. Conclusion: The early stages of periodontitis present acute response, and therefore result in rapid destruction of periodontal support tissues and potentially impair fibrillogenesis and collagen restructuring in the periodontal ligament.

Variability in the Epithelial Expression of Ki67 and Polarization Characteristics of Collagen in Odontogenic Cysts and Tumours

ABSTRACT Objective: To assess the proliferation of epithelium (using the Ki67 index) and the polarization pattern of collagen in selected odontogenic cysts and tumours. In addition, an exploratory analysis of the effect of inflammation on the proliferation rate was done. Material and Methods: Following immunohistochemical staining, the labelling/proliferation index of Ki67 was calculated. The thickness and corresponding polarization colour of 100 juxta-epithelial picrosirius red-stained collagen fibers were assessed using linear micrometry with an eyepiece reticule under × 1000 magnification. Inflammation was graded subjectively as mild, moderate, and severe. Results: Overall Ki-67 expression was higher in the radicular cyst, Odontogenic Keratocyst, Ameloblastoma, while suprabasal Ki-67 positivity was maximum in Odontogenic Keratocyst. The stromal collagen fibers in Ameloblastoma showed predominantly green birefringence, whereas Odontogenic Keratocyst had orange birefringence. There was no significant association of inflammation with Ki-67 expression or birefringence patterns. Conclusion: The highest Ki67 expression in the radicular cyst, followed by Odontogenic Keratocyst and Ameloblastoma. Differences in the collagen maturation pattern were noted innately in five lesions studied and were further influenced by inflammatory changes. Epithelial proliferation and concomitant expression of thickness and maturity of the stromal collagen are innate features of the lesion further influenced by inflammation in various odontogenic cysts and tumours and may, in turn, guide the clinical behavior.

Avaliação do efeito de biopartícula nas propriedades mecânicas, químicas e estruturais longitudinais da interface adesiva em dentina: estudo "in vitro" / Evaluation of the bioparticle effect on the mechanical, chemical and longitudinal structural properties of the dentin adhesive interface: an "in vitro" study

Este estudo, desenvolvido em duas etapas, avaliou a ação remineralizadora da biopartícula α-wollastonita (BP), a partir da reação com H3PO4 residual Si-O-Ca + H3PO4 → SiO2 + Ca5(PO4)3(OH)n + H2O, na resistência longitudinal de união e características da interface adesiva, quando aplicada na forma de suspensão (etanol 99,5% + 10% de BP em peso) na superfície dentinária previamente condicionada com H3PO4 37%. Na primeira etapa foi realizado um estudo piloto onde, pelas características de precipitação, foi identificada a melhor concentração de biopartículas a serem inseridas na formulação da suspensão. Na segunda etapa, duzentas coroas hígidas de incisivos bovinos foram embutidas em resina acrílica, polidas para padronizar a smear layer e divididas aleatoriamente em 2 grupos (n=100), segundo a estratégia adesiva: A - controle (H3PO4 + Single Bond™ Universal (SB)); WAS ­ (H3PO4 + BP em suspensão + SB). Blocos de resina composta (Filtek Z250; 3M/ESPE) de 4mm foram confeccionados por técnica incremental sobre as áreas tratadas em todos os grupos, utilizando uma matriz de silicona. As amostras foram então seccionadas para obtenção de palitos retangulares (aproximadamente 1mm2 ), armazenadas em água deionizada a 4ºC em recipientes individuais e divididas em 2 subgrupos (n=50) de acordo com o tempo de armazenamento de 24 h (imediato) e 12 meses (longitudinal), seguidos do teste de resistência adesiva à microtração (10 kgf, 0,5mm/min). Os dados foram submetidos ao teste ANOVA 2 fatores (p< 0,05) e teste de Weibull 2 parâmetros. As interfaces adesivas foram analisadas por microscopia eletrônica de varredura (MEV) para avaliar a morfologia da interface resina-dentina, e analisadas por espectroscopia FTIR, para compreensão das interações químicas formadas na superfície dentinária. Os Resultados evidenciaram maiores valores estatisticamente significativos de resistência de união (MPa) para o grupo WAS (37,39 ± 7,48), tratado com BP e armazenado por 24 h, em comparação ao grupo A armazenado por 24 h (27,58 ± 6,43); e, para o grupo WAS armazenado por 12 meses (32,05 ± 10,64) em comparação ao grupo A armazenado por 12 meses (22,84 ± 5,76). Dados do FTIR evidenciaram o efeito da α-wollastonita na preservação do colágeno. A biopartícula mostrou ser promissora na manutenção longitudinal da qualidade da interface adesiva. (AU)

This study, developed in two stages, evaluated the remineralizing action of the αwollastonite (BP) bioparticle, from the reaction with residual Si-O-Ca + H3PO4 → SiO2 + Ca5(PO4)3(OH)n + H2O, on the longitudinal bond strength and characteristics of the adhesive interface, when applied as a suspension (99.5% ethanol + 10% BP by weight) on the dentin surface previously etched with 37% H3PO4. In the first stage, a pilot study was carried out where, due to the precipitation characteristics, the best concentration of bioparticles to be inserted in the suspension formulation was identified. In the second step, two hundred sound bovine incisor crowns were embedded in acrylic resin, polished to standardize the smear layer and randomly divided into 2 groups (n=100), according to the adhesive strategy: A - control (H3PO4 + Single Bond™ Universal (SB)); WAS ­ (H3PO4 + BP in suspension + SB). Composite resin blocks (Filtek Z250; 3M/ESPE) of 4 mm were made by incremental technique on the treated areas in all groups, using a silicone matrix. The samples were then sectioned to obtain rectangular sticks (approximately 1mm2 ), stored in deionized water at 4ºC in individual containers and divided into 2 subgroups (n=50) according to the storage time of 24 h (immediate) and 12 months (longitudinal), followed by the microtensile bond strength test (10 kgf, 0.5 mm/min). Data were submitted to 2-way ANOVA (p<0.05) and 2-parameter Weibull test. The adhesive interfaces were analyzed by scanning electron microscopy (SEM) to evaluate the morphology of the resin-dentin interface, and analyzed by FTIR spectroscopy, to understand the chemical interactions formed on the dentin surface. The results showed higher statistically significant values of bond strength (MPa) for the WAS group (37.39 ± 7.48), treated with BP and stored for 24 h, compared to group A stored for 24 h (27, 58 ± 6.43); and for the WAS group stored for 12 months (32.05 ± 10.64) compared to group A stored for 12 months (22.84 ± 5.76). FTIR data evidenced the effect of α-wollastonite on collagen preservation. The bioparticle showed promise in the longitudinal maintenance of the quality of the adhesive interface (AU)

Antibioticoterapia sistêmica influencia na intensidade do infiltrado inflamatório e na reabsorção óssea da periodontite apical induzida / Systemic antibiotic therapy influences the intensity of the inflammatory infiltrate and bone resorption of induced apical periodontitis

Introdução: O objetivo deste trabalho foi investigar a influência da antibioticoterapia sistêmica no desenvolvimento e na progressão da periodontite apical em ratos Wistar. Material e Métodos: Foram utilizados 56 ratos distribuídos aleatoriamente em 7 grupos experimentais (n=8): Grupo C - controle; Grupo GEN ­ ratos tratados com Gentamicina (10mg/Kg, uma vez ao dia); Grupo AC ­ ratos tratados com Amoxicilina (100mg/Kg, uma vez ao dia); Grupo MZ ­ ratos tratados com Metronidazol (40mg/Kg, uma vez ao dia); Grupo AMP ­ ratos tratados com Ampicilina (100mg/Kg, uma vez ao dia); Grupo AC+XL ­ ratos tratados com Amoxicilina + Clavulanato de Potássio (100mg/kg, uma vez ao dia) e Grupo CLI ­ ratos tratados com Clindamicina (60mg/kg, uma vez ao dia). A periodontite apical foi induzida por meio da exposição pulpar do primeiro molar inferior do lado esquerdo. A antibióticoterapia foi iniciada no mesmo dia da exposição pulpar e teve duração de 15 dias. Após este período os animais foram sacrificados, as mandíbulas coletadas e processadas para análise histológica e histométrica em coloração de Hematoxilina e Eosina, análise das fibras colágenas pela coloração de Picrosirius red e análise bacteriológica por Brown-Brenn. Testes estatísticos foram aplicados (p< 0,05). Resultados: O grupo AC+XL apresentou menor intensidade do infiltrado inflamatório e menor reabsorção óssea periapical em relação ao grupo controle (p< 0.05). Quanto à maturação do colágeno o grupo AC+XL apresentou menor quantidade de fibras maduras e maior quantidade de fibras imaturas, comparado a todos os grupos (p< 0,05). Os grupos AC e AC+XL apresentaram menor extensão da contaminação bacteriana em relação ao controle (p< 0,05). Conclusão: A amoxicilina associada ao ácido clavulânico influencia o desenvolvimento e a progressão da periodontite apical induzida, reduzindo a intensidade do infiltrado inflamatório, maturação do colágeno e reabsorção óssea periapical, assim como a contaminação bacteriana no sistema de canais radiculares(AU)

Introduction: The aim of this work was to investigate the influence of systemic antibiotic therapy on the development and progression of apical periodontitis in Wistar rats. Material and Methods: 56 rats were randomly distributed in 7 experimental groups (n = 8): Group C - control; GEN group - rats treated with gentamicin (10mg / Kg, once daily); AC Group - rats treated with Amoxicillin (100mg / Kg, once a day); MZ group - rats treated with Metronidazole (40mg / Kg, once a day); AMP group - treated with Ampicillin (100mg / Kg, once a day); AM + C Group - rats treated with Amoxicillin + Potassium Clavulanate (100mg / kg, once a day) and CLI Group - rats treated with Clindamycin (60mg / kg, once a day). Apical periodontitis was induced through pulp exposure of the lower left first molar. Antibiotic therapy was given on the same day of pulp exposure and lasted for 15 days. After this period, the animals were sacrificed, with jaws collected and processed for histological and histometric analysis using Hematoxylin and Eosin staining, collagen fiber analysis using Picrosirius red staining and bacteriological analysis using Brown-Brenn. Statistical tests were conceptualized (p < 0.05). Results: The AC+XL group showed lower intensity of inflammatory infiltrate and lower periapical bone resorption compared to the control group (p < 0.05). As for collagen maturation, the AC+XL group had a smaller amount of mature fibers and a greater amount of immature fibers, compared to all groups (p < 0.05). The AC and AC+XL groups showed a smaller extent of bacterial contamination compared to the control (p< 0.05). Conclusion: Amoxicillin associated with clavulanic acid influences the development and progression of induced apical periodontitis in Wistar rats, causing the intensity of the inflammatory infiltrate, collagen maturation and periapical bone resorption, as well as bacterial contamination in the root canal system(AU)

Difference of Chemical Bonds Between UDMA Bonding Agents with Ethanol Solvent and Acetone Solvent on Dentin Collagen

ABSTRACT Objective: To investigate the difference of chemical bonds between urethane dimethacrylate (UDMA) bonding agents with ethanol solvent and acetone solvent on dentin collagen. Material and Methods: This experimental comparison study used three groups: G1 (Control): UDMA and collagen; G2: UDMA, collagen and ethanol; and G3: UDMA, collagen and acetone. The groups were then pelleted and analysed with FTIR, then the peak value of carbonyl absorption band from each study group was calculated. The result of FTIR analysis and the peak of carbonyl absorption band (P) was calculated using the formula: P = (BC / AB) X 100; AB. BC is measured in centimeters. The study of chemical bond differences between ethanol-solvent UDMA agents compared with acetone-solvent on dentin collagen resulted in a graph of peak of carbonyl absorption bands of UDMA and dentin collagen groups. To determine the chemical bonds of UDMA from the top of the carbonyl ester absorption bands with wavenumber absorption in range 1700-1750 cm-1, the decreasing peak of the carbonyl absorption bands is assumed as more chemical bonds that formed. Data were analysed using Anova one way and Tukey HSD test. Results: There were significant differences between the three study groups (p<0.05). Conclusion: UDMA bonding agents' chemical bonds with acetone solvent are much higher than the chemical bonds between UDMA bonding agents with ethanol solvent on dentin collagen.

Potencial de regeneração óssea guiada das membranas de colágeno porcino (Jason e Collprotect Straumann®): estudo histológico, histomorfométrico e Micro TC em defeitos ósseos de calvária de ratos / Potential for guided bone regeneration of porcine collagen membranes (Jason and Collprotect Straumann): histological, histomorphometric, and Micro CT study in bone defects of rat calvaria

A regeneração óssea guiada (ROG) tornou-se uma prática comum na Implantodontia e para sua realização, é necessário o uso de membranas que auxiliem neste processo. As membranas absorvíveis têm mostrado vantagens em relação às membranas não absorvíveis e entre as características mais relevantes das membranas absorvíveis estão: o aporte vascular, suporte mecânico do tecido ósseo e a não necessidade de um segundo estágio cirúrgico. Esse estudo teve como objetivo avaliar e comparar, por meio das análises histológica, histomorfométrica e Micro TC o potencial osteopromotor de duas membranas de colágeno porcino comercialmente disponíveis em defeitos críticos de calvária de ratos. Para o estudo foram utilizados 96 ratos Albinus Wistar, divididos em quatro grupos, sendo 24 animais para cada grupo: Grupos BG (BioGide®); JS (Jason®); CS (Collprotect®) e CG (Coágulo) analisados em quatro tempos experimentais, 7, 15, 30 e 60 dias. Os resultados mostraram um perfil inflamatório mais agressivo dos grupos JS e CS em relação ao grupo BG (p<005). O grupo JS, aos 60 dias apresentou um potencial osteopromotor satisfatório ao compara-lo com o grupo BG (p=0,193) e o grupo CS demonstrou o pior desempenho osteopromotor. Na análise tridimensional, os resultados anteriores foram confirmados com o pior desempenho em relação a menor média de tecido ósseo neoformado para o grupo CS de 84,901 mm², JS com 246,802 mm² e BG 319,834 mm² (p<0,05). Podemos concluir que apesar das membranas serem compostas pelo mesmo material, as diferentes áreas de obtenção, espessuras e técnicas de tratamento da membrana, podem interferir no seu comportamento biológico em relação á quantidade de osso neoformado e que o grupo CS apresentou os piores resultados quando comparado aos grupos JS e BG(AU)

Guided bone regeneration (ROG) has become a common practice in Implantology and for its realization, it is necessary to use membranes that assist in this process. Absorbable membranes have shown advantages over non-absorbable membranes and among the most relevant characteristics of absorbable membranes are vascular supply and mechanical support of bone tissue. This study aimed to evaluate and compare, through histological, histomorphometric, and Micro CT analyzes, the osteopromotive factor of two commercially available porcine collagen membranes in critical calvaria defects in rats. 96 Albinus Wistar rats were used for the study, divided into four groups, 24 animals for each group: BG Groups (BioGide®); JS (Jason®); CS (Collprotect®) and CG (Clot) analyzed in four experimental times, 7, 15, 30 and 60 days. The results showed a more aggressive inflammatory profile of the JS and CS groups in relation to the BG group (p <0.05). The JS group, at 60 days, presented a satisfactory osteopromotive factor when comparing it with the BG group (p = 0.193) and the CS group demonstrated the worst osteopromotive performance. In the three-dimensional analysis, the previous results were confirmed with the worst performance in relation to the lowest average total volume of newly formed bone for the CS group of 84,901 mm², JS with 246,802 mm² and BG 319,834 mm² (p<0,05). We can conclude that although the membranes are composed of the same material, the different areas of obtaining, thicknesses, and techniques of treatment of the membrane, can interfere in its biological behavior in relation to the amount of newly formed bone and that the CS group presented the worst results among the JS and BG group(AU)

Influência do LED Violeta associado ou não ao gel clareador na inflamação, mineralização e maturação colágena do tecido dentinário e pulpar / Influence of violet LED associated or not with peroxide gel on inflammation, mineralization, and collagen fiber maturation in dentin and pulp tissue

Objetivo: Avaliar a influência do LED Violeta, associado ou não ao gel clareador a base de peróxido de hidrogênio (PH) a 17,5% no complexo dentino-pulpar de ratos. Materiais e métodos: Molares superiores de 80 ratos foram distribuídos nos grupos (n = 10): CONT ­ sem tratamento, PH ­ 1 aplicação de 30 minutos de PH a 17,5%, LED ­ 1 aplicação de 20 minutos do LED Violeta, e PH+LED - aplicação do PH e LED Violeta. Imediatamente (T0), e aos 7 (T1), 15 (T2) e 30 dias (T3) após o tratamento, os ratos foram eutanasiados e as maxilas processadas para avaliação histológica, imunoistoquímica (IL-17, IL-23 e osteocalcina), e de picrosírius red, sendo realizados os testes de Wilcoxon e Mann-Whitney e Teste-T pareado e Teste-T, respectivamente. (α = 0,05). Resultados: Necrose e infiltrado inflamatório severo foram observados nos grupos PH e PH+LED. Apenas o grupo PH+LED manteve a imunomarcação severa para IL-17 e IL-23, diferindo do grupo LED e PH que apresentaram moderada imunomarcação em T0. Os grupos PH e PH+LED apresentaram severa imunomarcação de OCN em T2 e moderada imunomarcação em T3. O grupo LED apresentou menor quantidade de fibras imaturas em T2 e T3 que o grupo CONT. Conclusão: A terapia com LED violeta não induziu inflamação e fibrose no tecido pulpar, apesar de acelerar a maturação das fibras de colágeno da dentina e, quando associada ao peróxido de hidrogênio, pode tornar os dentes mais sensíveis(AU)

Objective: Was to evaluated the influence of the Violet LED, associated or not with a 17.5% hydrogen peroxide (HP) bleaching gel in the dentin-pulp complex of rats. Materials and methods: Upper molars of eighty Wistar rats were distributed in the groups (n = 10): CONT - without treatment, HP - 1 application of 30 minutes of 17.5% HP, LED - 1 application of 20 minutes of the Violet LED, and HP+LED - application of HP and LED Violet. Immediately (T0), and at 7 (T1), 15 (T2) and 30 days (T3) after treatment, the rats were euthanized and the jaws were processed for histological, immunohistochemical evaluation (IL-17, IL-23 and osteocalcin), and picrosirius red, with Wilcoxon and Mann-Whitney tests and paired T-test and T-test, respectively (α = 0.05). Results: Necrosis and severe inflammatory infiltrate were observed in the PH and PH+LED groups. Only the PH+LED group maintained severe immunostaining for IL-17 and IL-23, differing from the LED and PH group which presented moderate T0 immunostaining. The PH and PH+LED groups presented severe immunostaining of OCN in T2 and moderate immunostaining in T3. The LED group had a lower amount of immature fibers in T2 and T3 than the CONT group. Conclusion: Violet LED therapy induced no inflammation and fibrosis in the pulp tissue, however accelerating the maturation of dentin collagen fibers and, when associated with hydrogen peroxide, can make the teeth more sensitive(AU)

Biocompatibility, biomineralization, and maturation of collagen by rtr®, bioglass and dm bone® materials

Abstract This study evaluated the biocompatibility, biomineralization, and collagen fiber maturation induced by Resorbable Tissue Replacement (RTR®; β-tricalcium phosphate [TCP]), Bioglass (BIOG; bioactive glass), and DM Bone® (DMB; hydroxyapatite and β-TCP) in vivo. Sixty-four polyethylene tubes with or without (control group; CG) materials (n=8/group/period) were randomly implanted in the subcutaneous tissue of 16 male Wistar rats (four per rat), weighting 250 to 280 g. The rats were killed after 7 and 30 days (n=8), and the specimens were removed for analysis of inflammation using hematoxylin-eosin; biomineralization assay using von Kossa (VK) staining and polarized light (PL); and collagen fiber maturation using picrosirius red (PSR). Nonparametric data were statistically analyzed by Kruskal-Wallis and Dunn tests, and parametric data by one-way ANOVA test (p<0.05). At 7 days, all groups induced moderate inflammation (p>0.05). At 30 days, there was mild inflammation in the BIOG and CG, and moderate inflammation in the RTR and DMB groups, with a significant difference between the CG and RTR (p<0.05). The fibrous capsule was thick at 7 days and predominantly thin at 30 days in all groups. All materials exhibited structures that stained positively for VK and PL. Immature collagen fibers were predominant at 7 and 30 days in all groups (p>0.05), although DMB exhibited more mature fibers than BIOG at 30 days (p<0.05). RTR, BIOG, and DMB were biocompatible, inducing inflammation that reduced over time and biomineralization in the subcutaneous tissue of rats. DMB exhibited more mature collagen fibers than BIOG over a longer period.

Resumo Este estudo avaliou a biocompatibilidade, biomineralização e maturação das fibras de colágeno induzidas por Resorbable Tissue Replacement (RTR®; fosfato β-tricálcico [TCP]), Bioglass (BIOG; vidro bioativo) e DM Bone® (DMB; hidroxiapatita e β-TCP) in vivo. Sessenta e quatro tubos de polietileno com ou sem (grupo controle; GC) os materiais (n=8/grupo/período) foram implantados aleatoriamente em tecido subcutâneo de 16 ratos machos Wistar (quatro por rato), pesando entre 250 a 280g. Os ratos foram mortos após 7 e 30 dias (n=8), e as amostras foram removidas para análise da inflamação utilizando hematoxilina-eosina; avaliação da biomineralização utilizando coloração de von Kossa (VK) e luz polarizada (LP); e maturação das fibras colágenas, utilizando picrosirius red (PSR). Os dados não-paramétricos foram analisados pelos testes de Kruskal-Wallis e Dunn, e os paramétricos pelo teste de one-way ANOVA (p<0.05). Aos 7 dias, todos os grupos induziram inflamação moderada (p>0,05). Aos 30 dias, houve inflamação leve nos grupos BIOG e GC, e inflamação moderada nos grupos RTR e DMB, com diferença significativa entre os GC e RTR (p<0,05). A cápsula fibrosa foi espessa aos 7 dias, e predominantemente fina aos 30 dias em todos os grupos. Todos os materiais exibiram estruturas positivas para VK e LP. Fibras colágenas imaturas foram predominantes aos 7 e 30 dias em todos os grupos (p>0,05), embora o DMB exibiu fibras mais maduras do que o BIOG aos 30 dias (p<0,05). RTR, BIOG e DMB foram biocompatíveis, induzindo inflamação que reduziu com o tempo, e biomineralização no tecido subcutâneo de ratos. O DMB exibiu mais fibras colágenas maduras do que o BIOG em período mais longo.

Influência das suplementações de ômega-3 e melatonina sobre a resposta tecidual de diferentes cimentos endodônticos / The influence of the supplementation of Omega 3 and melatonin on tissue response of different endodontic sealers

O objetivo deste estudo foi avaliar a influência das suplementações de ômega-3 e melatonina sobre a resposta tecidual de cimentos endodônticos. Foram utilizados 72 ratos Wistar alocados em 3 grupos principais: ratos controle tratados com água (TA), ratos tratados com ômega-3 (TO) e ratos tratados com melatonina (TM). Em cada rato foram implantados 4 tubos de polietileno, sendo 1 tubo vazio para controle, e os demais contendo um dos cimentos endodônticos: Sealapex®, AH Plus® e Endofil®. Os períodos de avaliação foram de 5, 15 e 30 dias (n=8/tempo). Após eutanásia, os tubos foram removidos e processados para análise microscópica. A inflamação foi avaliada em coloração de H.E. e técnica imunohistoquímica para IL-6 e TNF-α, o colágeno pela coloração de Picrosírios red e a deposição de cálcio, pela técnica de von Kossa e luz polarizada. A estatística foi realizada de acordo com cada tipo de análise, com nível de significância de 5% (p <0,05) e considerando cada tipo de suplementação comparado ao controle. Podese observar infiltrado inflamatório reduzido com o tempo e de menor intensidade nos grupos TO ou TM comparado a TA, assim como a imunomarcação para IL-6 e TNF-α. O cimento Sealapex induziu menor inflamação aos 30 dias, tanto em TO quanto em TM. Em relação ao colágeno, foi observado maior expressão de fibras imaturas no grupo TO aos 15 e 30 dias, entretanto, no grupo TM, foi observado maior quantidade de fibras maduras aos 5 dias, ambos comparados a TA. O cimento Sealapex foi único a apresentar marcação positiva para cálcio e cristais de calcita birrefringentes à luz polarizada, independente das suplementações. Pode-se concluir que a suplementação com ômega-3 ou melatonina modularam a inflamação, diminuindo o infiltrado inflamatório e a imunomarcação de IL-6 e TNF- α, estimularam o reparo tecidual e não influenciaram no processo de deposição de cálcio(AU)

The aim of this study was to evaluate the influence of omega-3 and melatonin supplements on the tissue response of endodontic sealers. 72 Wistar rats were allocated in 3 main groups: control rats treated with water (TW), rats treated with omega-3 (TO) and rats treated with melatonin (TM). In each rat, 4 polyethylene tubes were implanted, 1 empty tube for control, and the others containing one of the endodontic sealers: Sealapex®, AH Plus® and Endofil®. The evaluation periods were of 5, 15 and 30 days (n = 8 / time). After euthanasia, the tubes were removed and processed for microscopic analysis. Inflammation was evaluated in H.E. staining and immunohistochemical technique for IL-6 and TNF-α, collagen by Picrosírios red staining and calcium deposition by von Kossa and polarized light technique. Statistics were performed according to each type of analysis, with a significance level of 5% (p <0.05) and considering each type of supplementation compared to the control. It is possible to observe a reduced inflammatory infiltrate over time and less intensity in the TO or TM groups compared to TW, as well as the immunolabeling for IL-6 and TNF-α. Sealapex sealer induced less inflammation at 30 days, both in TO and TM. Regarding collagen, a greater expression of immature fibers was observed in the TO group at 15 and 30 days, however, in the TM group, a greater amount of mature fibers was observed at 5 days, both compared to TW. Sealapex sealer was the only one to present positive marking for calcium and birefringent calcite crystals under polarized light, regardless of supplementation. It can be concluded that supplementation with omega-3 or melatonin modulated the inflammation, reducing the inflammatory infiltrate and the immunolabeling of IL-6 and TNF-α, they stimulated tissue repair and did not influence the calcium deposition process(AU)

Efficacy of the Tent-Pole Technique in Horizontal Ridge Augmentation

Abstract Objective: To evaluate the efficacy of the technique for ridge augmentation prior to implant placement. Material and Methods: Six patients with nine sites presenting an initial ridge width of smaller than 4 mm were included in this study. The tent-pole technique (combination of osteosynthesis screws measuring 1.5 mm in diameter, ABBM, and resorbable collagen membrane) was applied at defect sites. After eight months of healing time, implants were placed in the treated sites. The primary outcomes (radiographic initial ridge width, re-entry ridge width, ridge width gain) were measured by cone-beam computed tomography in reference buccopalatal cross-sections and the secondary outcomes (clinical parameters) were recorded by a digital caliper at the first and second stages. Results: After grafting, the radiographic ridge width increased by 3.02 ± 1.11 mm (1.57-4.75 mm) at 2 mm below the crest and 3.32 ± 1.70 mm (0.23-5.66 mm) at 6 mm below the crest significantly (p< 0.05). For clinical results, the mean horizontal dimension gain was 3.21 ± 1.04 mm (1.83-4.57 mm), while the mean reduction in dimension was 0.38 ± 0.33 mm. These results were statistically significant (p<0.05). Uneventful healing and no infections or membrane exposure were recorded at all sites during the study process. Three of nine (33.33%) defect sites required additional bone grafting. Conclusion: The tent-pole technique is an effective method for increasing the horizontal ridge dimension, minimizing postoperative complications, and facilitating subsequent implant placement.

Avaliação da regeneração óssea guiada por meio do uso de membrana de colágeno bovino associada à hidroxiapatita em defeitos críticos na calvária de ratos: análises histomorfométrica e imunoistoquímica / Evaluation of guided bone regeneration through the use of a color membrane associated with hydroxyapatite in critical defects in rat calvaria: histomorphometric and immunohistochemical study

O uso de membranas que auxiliem no processo de regeneração óssea guiada (ROG) é uma vertente dos estudos de biomateriais compatíveis que auxiliam no processo de reparo por meio da osteopromoção. O objetivo deste trabalho foi avaliar e comparar a regeneração óssea guiada utilizando membranas de colágeno de origens diferentes em defeitos críticos criados em calvária de ratos. Materiais e métodos: foram utilizados 72 ratos Albinus Wistar divididos em 3 grupos, sendo 6 animais para cada grupo: grupo controle somente com coágulo; grupo que recebeu a membrana de colágeno porcina (Bio-Gide®) e grupo de membrana de colágeno bovino associado à hidroxiapatita sintética (Col.HAP-91®). Foram estudados os períodos de 7, 15, 30 e 60 dias pós-operatórios através de lâminas submetidas as análises histomorfométricas e imunohistoquímicas. Os resultados histológicos demonstraram que o grupo controle positivo (BioGide®) apresentou neoformação óssea mais avançada aos 30 dias em comparação ao grupo coágulo e grupo experimental (Col.HAP-91®). Aos 60 dias observou-se similaridade quanto a neoformação óssea entre os grupos BioGide® e Col.HAP.91®. Esses resultados foram corroborados pelos resultados da imunoistoquímica. Diante dos resultados obtidos conclui-se que, todas as membranas estudadas nesta pesquisa promoveram a ROG(AU)

The use of membranes that aid in the guided bone regeneration (ROG) process is also a part of compatible biomaterial studies that aid in this repair process. Objective: To evaluate and compare guided bone regeneration using membranes from different origins in critical defects created in calvaria of rats. Materials and methods: We will use 72 Albinus Wistar rats divided into 3 groups, 6 of which were animals for each group: control group with clot only; group that received the porcine collagen membrane (BioGide®) and synthetic hydroxyapatite membrane group associated with collagen (Col.HAP-91®). The animals will be euthanized at 7, 15, 30 and 60 postoperative days. Laboratory procedures will be performed and histomorphometric and immunohistochemical analyzes will be performed. Histological results showed that the positive control group (BioGide®) presented more advanced bone formation at 30 days compared to the clot group and the experimental group (Col.HAP-91®). At 60 days, there was a similarity in bone neoformation between the BioGide® and Col.HAP.91® groups. These results were confirmed by iminohistochemistry. In view of the results obtained, it is concluded that all membranes studied in this research promoted guided bone regeneration(AU)

Avaliação da regeneração óssea guiada por meio histológico, histométrico, imunoistoquímico e perfil inflamatório de membranas reabsorvíveis de colágeno porcino em defeitos críticos em calotas de ratos / Evaluation histological, histometric, immunohistochemistry analysis and inflammatory profile of bone-guided regeneration with membranes of reabsorbable porcine collagen in critical defects in rodent skullcaps

A regeneração óssea guiada (RGO) tornou-se uma prática comum e importante na odontologia, sendo necessário o uso de membranas para sua realização, uma vez que são barreiras que evitam o crescimento de tecido mole nas áreas de defeitos ósseos. Entre as características mais relevantes das membranas absorvíveis estão: o suporte sanguíneo (diretamente relacionado com a porosidade do material) e suporte mecânico ósseo que depende do tempo de reabsorção da membrana. O objetivo desse estudo foi avaliar e comparar duas membranas de colágeno por meio de estudo histológico, histomorfométrico, imunoistoquímico e por contagem de células inflamatórias o processo de regeneração óssea guiada utilizando a membrana de colágeno derivada de pericárdio porcino (Jason®-Instituto Straumann AG, Suíça) em defeitos críticos de 7 mm de diâmetro criados em setenta e duas calvárias de ratos (Rattus Albinus, variedade Wistar). Esses animais foram divididos em 3 grupos: grupo membrana de colágeno porcino (BioGide® - Geistlich Wohlhusen, Suíça), grupo membrana de colágeno de pericárdio porcino (Jason®-Instituto Straumann AG, Suíça) e grupo coágulo, sendo este preenchidos somente com coágulo sem membrana. Esses 3 grupos forma subdivididos em quatro subgrupos de acordo com os tempos avaliados: 7, 15, 30 e 60 dias. Como resultado tivemos na análise histológica e histométrica maior neoformação óssea com o grupo de membrana pericárdio porcino nos períodos de 7 dias (199 pontos) e não foi significante, com 15 dias (494 pontos) estatisticamente significativo, com 30 dias (979 pontos) não significante. Esses valores se modificam 60 dias, mostrando maior superioridade a membrana de colágeno porcino (BioGide®- Geistlich Wohlhusen, Suíça) (1151 pontos) estatisticamente significativo. No analises global a membrana de colágeno porcino (Jason®-Instituto Straumann AG, Suíça) foi superior que a membrana de pericárdio porcino (BioGide®- Geistlich Wohlhusen, Suíça) (p= 0,021) estatisticamente significativo. A análise imunoistoquímica confirmou os achados histométricos, demostrando maior presença da osteocalcina no grupo de pericárdio porcino aos 7 e 15 dias e presença da osteopontina pouco evidente. Já com a membrana de colágeno porcino a osteopontina foi mais imunomarcada aos períodos de 7 e 15 dias, e a presencia de osteocalcina mais evidente aos 30 e 60 dias, corroborando com os resultados iniciais. Na contagem de células inflamatórias para o tempo de 7 dias não houve diferenças estatísticas, já na contagem de vasos sanguíneos houve diferença significativa no período de 15 dias com maior quantidade de vasos para membrana de colágeno porcino, com estes achados concluímos que tanto a membrana de colágeno de pericárdio porcino (Jason® -Instituto Straumann AG, Suíça) quanto a membrana de colágeno porcino (BioGide®-Geistlich Wohlhusen, Suíça) podem ser consideradas como material de escolha apropriada para regeneração óssea guiada, com maior proporção de osso neoformado com a membrana de colágeno porcino(AU)

Guided bone regeneration (RGO) has become a common and important practice in dentistry, requiring the use of membranes to perform it, since they are barriers that prevent the growth of soft tissue in areas of bone defects. Among the most relevant characteristics of absorbable membranes are: blood support (directly related to the porosity of the material) and mechanical bone support that depends on the time of membrane resorption. The goal of this study was to evaluate and compare two collagen membranes by means of histological, histomorphometric, immunohistochemical study and by inflammatory cell counting the guided bone regeneration process using the collagen membrane derived from porcine pericardium (Jason®-Instituto Straumann AG, Switzerland) in critical defects of 7 mm in diameter created in seventy-two calvaria of rats (Rattus Albinus, Wistar variety). These animals were divided into 3 groups: porcine collagen membrane group (BioGide® - Geistlich Wohlhusen, Switzerland), porcine pericardium collagen group (Jason®-Instituto Straumann AG, Switzerland) and clot group, which were filled with only a clot without membrane. These 3 groups were subdivided into four subgroups according to the evaluated times: 7, 15, 30 and 60 days. As a result, we had a greater bone neoformation in the histological and histometric analysis with the porcine pericardial membrane group in the periods of 7 days (199 points) and it was not statistically significant with 15 days (494 points), with 30 days (979 points) not significant. These values change 60 days, showing greater superiority to the porcine collagen membrane (BioGide®- Geistlich Wohlhusen, Switzerland) (1151 points) statistically significant. In the global analysis, the porcine collagen membrane (Jason®Instituto Straumann AG, Switzerland) was superior than the porcine pericardium membrane (BioGide®- Geistlich Wohlhusen, Switzerland) (p = 0.021) statistically significant. The immunohistochemical analysis confirmed the histometric findings, showing a greater presence of osteocalcin in the porcine pericardium group at 7 and 15 days and the presence of osteopontin little evident. As for the porcine collagen membrane, osteopontin was more immunostained at 7 and 15 days, and the presence of osteocalcin was more evident at 30 and 60 days, corroborating the initial results. In the inflammatory cell count for the 7-day period, there were no statistical differences, whereas in the blood vessel count, there was a significant difference in the 15-day period with a greater number of vessels for porcine collagen membrane, with these findings we conclude that both the porcine pericardial collagen (Jason® - Straumann AG Institute, Switzerland) and porcine collagen membrane (BioGide®-Geistlich Wohlhusen, Switzerland) can be considered as the material of choice for guided bone regeneration, with a higher proportion of neoformed bone according to porcine collagen membrane(AU)

Ameloblastoma cell lines derived from different subtypes demonstrate distinct developmental patterns in a novel animal experimental model

Abstract Objective Ameloblastoma is a representative odontogenic tumor comprising several characteristic invasive forms, and its pathophysiology has not been sufficiently elucidated. A stable animal experimental model using immortalized cell lines is crucial to explain the factors causing differences among the subtypes of ameloblastoma, but this model has not yet been disclosed. In this study, a novel animal experimental model has been established, using immortalized human ameloblastoma-derived cell lines. Methodology Ameloblastoma cells suspended in Matrigel were subcutaneously transplanted into the heads of immunodeficient mice. Two immortalized human ameloblastoma cell lines were used: AM-1 cells derived from the plexiform type and AM-3 cells derived from the follicular type. The tissues were evaluated histologically 30, 60, and 90 days after transplantation. Results Tumor masses formed in all transplanted mice. In addition, the tumors formed in each group transplanted with different ameloblastoma cells were histologically distinct: the tumors in the group transplanted with AM-1 cells were similar to the plexiform type, and those in the group transplanted with AM-3-cells were similar to the follicular type. Conclusions A novel, stable animal experimental model of ameloblastoma was established using two cell lines derived from different subtypes of the tumor. This model can help clarify its pathophysiology and hasten the development of new ameloblastoma treatment strategies.

Clareamento dentário com LED violeta: efeitos na alteração cromática, resistência de união, nanodureza da camada híbrida e resistência do colágeno / Dental bleaching with violet light: effects on color change, bonding strength, nanohardness of hybrid layer and collagen strength

O propósito deste projeto foi investigar a alteração cromática, resistência de união de restaurações resinosas à dentina, bem como analisar nanodureza da camada híbrida e a resistência coesiva do colágeno dentinário, após realização de diferentes técnicas clareadoras. Para tanto, 75 dentes bovinos foram aleatoriamente distribuídos: Grupo controle; Grupo LED e Grupo GEL. Em seguida, 45 dentes (n=15) foram destinados à análise da alteração cromática, sendo posteriormente preparados, restaurados e seccionados em palitos. Metade das amostras foram submetidas aos testes de resistência de união e propriedades mecânicas da camada híbrida, o restante sofreu 10000 ciclos térmicos antes das avaliações. Os 30 dentes remanescentes foram empregados na análise da resistência coesiva do colágeno (n=10), que foi realizada imediatamente após a realização dos tratamentos clareadores, bem como após a ação da colagenase. Os dados obtidos da cor, resistência de união, propriedades mecânicas e resistência coesiva do colágeno foram analisados quanto à normalidade utilizando o teste Shapiro-Wilk e submetidos ao teste ANOVA dois fatores com medidas repetidas e pós teste de Tukey (α=0,05). Houve alteração cromática em Grupo LED e GEL, com maiores alterações de ∆E, ∆L e ∆b em GEL. No teste de adesão somente a termociclagem interferiu nos resultados, apresentando menores valores em todos os grupos. Valores de nanodureza e módulo de elasticidade permaneceram inalterados após os tratamentos (p>0,05), enquanto que no teste de resistência coesiva do colágeno, na análise imediata o Grupo GEL apresentou diferença do controle, apresentando menores valores, sendo LED semelhante à ambos. Avaliando os grupos após degradação enzimática, observa-se o mesmo comportamento. Todos os grupos sofreram influência da degradação enzimática (p<0,05), com menores valores de resistência após o desafio. Portanto, o emprego do LED violeta apresentou alteração cromática, porém, em menor intensidade que o uso de géis à base de peróxidos. Não houve alterações nas propriedades mecânicas e adesivas, no entanto, houve menor resistência coesiva do colágeno após o tratamento com gel, bem como, após degradação enzimática em todos os grupos avaliados(AU)

The aim of this project was to investigate the chromatic alteration, bond strength of dentin resin restorations, as well as to analyze the nanohardness of the hybrid layer and the cohesive strength of dentin collagen, after performing different bleaching techniqu es. For this, 75 bovine teeth were randomly distributed: Control group; LED Group and GEL Group. Then, 45 teeth (n = 15) were destined to the analysis of the color change, being subsequently prepared, restored and sectioned on sticks. Half of the samples w ere submitted to the bond strength and mechanical properties tests of the hybrid layer, the remaining 10000 thermal cycles before the evaluations. The remaining 30 teeth were used to analyze collagen cohesive resistance (n = 10), which was performed immedi ately after bleaching treatments, as well as after collagenase action. The data obtained on color, bond strength, mechanical properties and collagen cohesive resistance were analyzed for normality using the Shapiro-Wilk test and submitted to the twoway ANOVA test with repeated measures and Tukey test (α = 0.05). . There was chromatic alteration in LED and GEL Group, with larger alterations of ∆E, ∆L and ∆b in GEL. In the adhesion test only thermocycling interfered in the results, presenting lower values in all groups. Nanohardness and modulus of elasticity values remained unchanged after the treatments (p> 0.05), while in the collagen cohesive resistance test, in the immediate analysis the GEL Group presented a control difference, presenting lower value \ LED similar to both. . Evaluating the groups after enzymatic s, being degradation, the same behavior is observed. All groups were influenced by enzymatic degradation (p <0.05), with lower resistance values of violet L after challenge. Therefore, the use ED showed chromatic alteration, however, to a lesser extent than the use of peroxidebased gels. There were no changes in mechanical and adhesive properties, however, there was less cohesive collagen resistance after gel treatment, as well as after enzymat ic degradation in all groups evaluated(AU)

The influence of Aloe vera with mesenchymal stem cells from dental pulp on bone regeneration: characterization and treatment of non-critical defects of the tibia in rats

Abstract Objective This study aimed to evaluate the inflammatory effect and bone formation in sterile surgical failures after implantation of a collagen sponge with mesenchymal stem cells from human dental pulp (hDPSCs) and Aloe vera. Material and Methods Rattus norvegicus (n=75) were divided into five experimental groups according to treatment: G1) control (blood clot); G2) Hemospon®; G3) Hemospon® in a culture medium enriched with 8% Aloe vera; G4) Hemospon® in a culture medium containing hDPSCs and G5) Hemospon® in a culture medium enriched with 8% Aloe vera and hDPSCs. On days 7, 15 and 30, the animals were euthanized, and the tibia was dissected for histological, immunohistochemistry and immunofluorescence analyses. The results were analyzed using nonparametric Kruskal-Wallis test and Dunn's post-test. Results On days 7 and 15, the groups with Aloe vera had less average acute inflammatory infiltrate compared to the control group and the group with Hemospon® (p<0.05). No statistically significant difference was found between the groups regarding bone formation at the three experimental points in time. Osteopontin expression corroborated the intensity of bone formation. Fluorescence microscopy revealed positive labeling with Q-Tracker® in hDPSCs before transplantation and tissue repair. Conclusion The results suggest that the combination of Hemospon®, Aloe vera and hDPSCs is a form of clinical treatment for the repair of non-critical bone defects that reduces the inflammatory cascade's effects.

Avaliação da regeneração óssea guiada em defeitos críticos com o uso de membranas de colágeno bovino e porcino: análises histológica, histomorfométrica e imunoistoquímica / . Evaluation of guided bone regeneration in critical defects with the use of bovine and porcine collagen membranes: histological, histomorphometric and immunohistochemical analysis

O objetivo deste estudo foi avaliar a eficácia da membrana colagenosa bovina e a porcina, por meio das análises histológica, histométrica e imunoistoquímica comparando-a com a eficácia da membrana colágeno porcino no processo de reparo de defeitos ósseos críticos em calvária de ratos. Para este estudo foram utilizados 72 ratos divididos em três grupos: Grupo Coágulo (GC), Grupo Colágeno Bovino (GCB), Grupo Colágeno Porcino (GCP) e foram feitas as análises nos períodos de 7, 15, 30 e 60 dias. Os resultados histológicos demonstraram que o GCP apresentou início de neoformação óssea a partir do 70 dia sendo que aos 30 dias de reparo houve o preenchimento do defeito cirúrgico tendo o fechamento completo em alguns animais. Para o GCB foi pouca atividade de neoformação óssea nos períodos iniciais, sendo que a partir dos 30 dias observou-se uma crescente neoformação óssea tendo um aumento importante aos 60 dias. Os dados obtidos na análise histométrica revelam que aos 30 dias a área de osso neoformado (AON) não teve grande discrepância para o GCP em relação ao GCB, mas teve de ambos em relação ao GC, já em 60 dias o GCP apresentou maior AON em relação ao GCB. Esses resultados foram corroborados pelos resultados da imunoistoquímica. Diante dos resultados obtidos conclui-se que, todas as membranas estudadas nesta pesquisa promoveram a ROG(AU)

The objective of this study was to evaluate the effectiveness of the bovine and porcine collagenous membrane by means of histological, histometric and immunohistochemical analysis comparing it with the efficiency of the porcine collagen membrane in the process of repair of critical bone defects in calvaria of rats. For this study, 72 rats were divided into three groups: Group Clot (GC), Group Bovine Collagen (GCB), Porcine Collagen Group (GCP) and analyzes were performed at 7, 15, 30 and 60 days. The histological results demonstrated that GCP presented onset of bone neoformation from day 7 and at 30 days of repair there was filling of the surgical defect and complete closure in some animals. For GCB, there was little activity of bone neoformation in the initial periods, and from the 30 days a growing bone neoformation was observed, with a significant increase at 60 days. The data obtained in the histometric analysis revealed that at 30 days the area of newly formed bone (AON) did not have a great discrepancy for GCP in relation to GCB, but had both in relation to CG, and in 60 days GCP presented higher AON in relation to GCB. These results were corroborated by the results of immunohistochemistry. In view of the obtained results it is concluded that, all the membranes studied in this research promoted ROG(AU)

Comparação do enxerto de tecido conjuntivo e de uma matriz de colágeno xenógena no recobrimento radicular de recessões gengivais unitárias em fenótipo gengival fino / Comparison of connective tissue graft and a xenogeneic collagen matrix in root coverage of single gingival recessions in thin gingival phenotype

As recessões gengivais podem causar hipersensibilidade dentinária, desconforto estético e aumentar a prevalência de cáries ou lesões cervicais não-cariosas. Cirurgias para recobrimento radicular associadas a enxertos têm sido consideradas padrão ouro no tratamento das recessões gengivais. OBJETIVO: Comparar o enxerto de tecido conjuntivo e uma matriz de colágeno xenógena no recobrimento radicular de recessões gengivais unitárias em fenótipo gengival fino, em 6 meses de acompanhamento. METODOLOGIA: Este ensaio clínico, controlado, randomizado, duplo cego, de boca dividida, avaliou 28 pacientes com recessões gengivais bilaterais submetidos à cirurgia para recobrimento radicular, através do retalho estendido associado ao enxerto de tecido conjuntivo subepitelial (grupo controle) e matriz de colágeno (grupo teste). Os parâmetros avaliados foram profundidade de sondagem, recessão gengival, nível clínico de inserção, mucosa ceratinizada e sangramento à sondagem tanto dos dentes que receberam os enxertos, como dos dentes distais e mesiais a esse. Além de espessura gengival e alteração do fenótipo gengival dos dentes que receberam os enxertos, dor pós-operatória e qualidade de vida, através do Oral Health-Related Quality of Life, no baseline, três e seis meses após a cirurgia. Os dados foram analisados estatisticamente através dos testes de Friedman, Wilcoxon, Mann-Whitney, Qui-quadrado, McNemar, ANOVA e teste t, sendo pré-estabelecido um nível de significância de 5%. RESULTADOS: 14 homens e 14 mulheres foram incluídos, com uma média de idade de 30,3 (± 6,2) anos. Foram observadas reduções estatisticamente significativas para a recessão gengival e ganho significativo do nível clínico de inserção tanto dos dentes que receberam os enxertos (p<0,001), como dos dentes distais (p=0,001) e mesiais (p<0,001), na análise intragrupo, em ambos os grupos de tratamento, nos períodos avaliados. Além disso, houve aumento significativo da mucosa ceratinizada (p<0,001) e espessura gengival (p<0,001) para os grupos teste e controle, respectivamente, com diferença significativa entre os grupos de tratamento. O protocolo de tratamento proposto também foi capaz melhorar a qualidade de vida (p<0,001). CONCLUSÃO: Ambos os tratamentos resultaram em melhoria dos parâmetros clínicos avaliados em seis meses de acompanhamento. A matriz de colágeno representa uma excelente alternativa ao enxerto de tecido conjuntivo subepitelial no tratamento de recessões gengivais unitárias em fenótipo gengival fino (AU).

Gingival recession may cause dental hypersensitivity, esthetical discomfort and increase the prevalence of carious or non-carious cervical lesion. Root coverage procedures using grafts placement has been the gold standard on this treatment. AIM: To compare the root coverage performed connective tissue graft and collagen matrix using the extended flap technique in single gingival recessions in thin gingival phenotype, at 6 months of follow- up. METHOD: This controlled, randomized, double-blind, split-mouth, clinical trial evaluated 28 patients with bilateral gingival recession subjected to root coverage procedure through extended flap technique with subepithelial connective tissue graft (control) and xenogenic collagen matrix (test). The parameters evaluated were deep on probing, gingival recession, clinical attachment level, keratinized mucosa and bleeding on probing for teeth that received the graft and the distal and mesial teeth. In addition, gingival thickness and gingival phenotype change of the teeth that received the grafts, postoperative pain and quality of life through Oral Health-Related Quality of Life, at baseline, three and six months after surgery. The data were statistically analyzed through the tests of Friedman, Wilcoxon, Mann-Whitney, Qui-quadrado, McNemar, ANOVA and t Test. The significance level of 5% was pre-estlablished. RESULTS: 14 men and 14 women were included, with an average of 30.3 years (± 6.2). Statistically significant reductions were observed for gingival recession and clinical attachment level significant increase of both teeth of the grafts (p <0.001), distal (p=0.001) and mesial (p<0.001) teeth, within each group and in both treatment groups, during the follow-up. In addition, there was keratinized mucosa significant increase (p <0.001) and gingival thickness (p<0.001) for test and control group, respectively, with statistical difference between groups. The treatment protocol was able to improve the quality of lite (p<0.001). CONCLUSION: Both treatments resulted in improved clinical parameters at six months of follow-up. The collagen matrix represents an excellent alternative to the subepithelial connective tissue graft in the treatment of single gingival recessions in thin gingival phenotype (AU)

Comparison of two soft tissue substitutes for the treatment of gingival recession defects: an animal histological study

Abstract Objectives: This study aimed to compare two different soft tissue replacement grafts in their ability to treat gingival recession defects and successfully integrate with the surrounding tissues. Methodology: Nine beagle dogs were included and followed up to 10 weeks. Sites for intervention were allocated to one of the grafting materials investigated. Treatment consisted of coronally advanced flap combined with one of the two soft tissue substitutes on a previous surgically created defect. Materials employed were porcine-derived acellular dermal matrix (ADM) [Novomatrix™ (Test)] and collagen-based matrix (CBM) [Mucograft® (Control)]. Animals were sacrificed at 2, 6, and 10 weeks postoperatively and compared using descriptive histology and histomorphometric outcomes. Results: Macroscopic findings were similar between test and control groups at all intervals. After 10 weeks, both groups demonstrated successful incorporation of the grafting materials without signs of rejection and with comparable tissue integration. The histomorphometric data were similar between groups at 2 weeks; however, the test group provided greater root coverage and increase in tissue thickness than the control at 6- and 10-weeks post surgically. Conclusions: Both porcine-derived ADM and CBM revealed similar histological outcomes with successful integration and absence of adverse events. Test group provided superior outcomes regarding root coverage and increase in tissue thickness.

Treatment of multiple recessions with collagen matrix versus connective tissue: a randomized clinical trial

Abstract The objective of this study was to determine whether collagen matrix (CM) is an alternative to connective tissue graft technique (CTG) in the treatment of multiple gingival recessions (GR). The indication of CM for the treatment of multiple GR is not yet clear. More studies are needed to better understand this treatment modality, as an alternative to CTG. In this single-blind, split-mouth randomized clinical trial, fifteen patients with multiple Miller class I upper GR were selected and randomly assigned to control group (CTG) or test group (CM). Root coverage (RC) and patient-centered outcomes were evaluated at baseline and after 3, 6, and 12 months. A total of 82 GRs were treated. There was no significant difference regarding GR depth (GRD, primary outcome) between CTG (0.5 ± 0.9 mm) and CM groups (0.6 ± 1.0 mm) (p = 0.225). Percentage of RC was 82.14% in CTG and 77.7% in CM. Both groups demonstrated a gain in keratinized tissue width at 12 months (p < 0.05). Dentine hypersensitivity was effectively reduced in both groups. Postoperative pain was significantly higher in the CTG (p = 0.001). Esthetic satisfaction was high for both groups, with no significant difference (p > 0.05) between groups. After 12 months, both surgical treatments were able to promote RC, and GRD was similar in both CTG and CM groups.

Papel da MMP-9 e do TGF-ß na expressão de componentes da Matriz Extracelular por fibroblastos gengivais de camundongos normais e diabéticos com doença periodontal in vitro / Role of MMP-9 and TGF-ß on extracellular matrix components expression by in vitro fibroblasts from normal and diabetic mice with periodontal disease

Na presença de Diabetes Mellitus, a doença periodontal (DP) pode acentuar o aparecimento de complicações e aumentar sua prevalência. O objetivo desta pesquisa foi avaliar se o Fator de Crescimento Transformador -ß do tipo 1 (TGFß1, sigla em inglês) e Metaloproteinase de matriz -9 (MMP-9, sigla em ingês) estão modulando a formação de componentes de matriz extracelular em fibroblastos gengivais (FG) de camundongos diabéticos e com DP. Os 24 animais foram separados em 4 grupos, e então foram tratados com estreptozotocina para indução de diabetes e foi realizado indução da DP através de ligadura com fio de seda. Após a eutanásia e coleta da gengiva, FG dos camundongos foram cultivados. A expressão gênica de RNAm e produção de proteína para MMP-9, TGF-ß1 e colágeno tipo 1 (Col1a1) foram avaliadas. Eles também foram tratados com inibidores de MMP-9 e TGF-ß1, e dexametasona (Dexa) por 24h. FG de animais normais e diabéticos com DP induzida tiveram expressão aumentada de MMP-9 e TGF-ß1 em 6 e 24h, diminuindo em 48h. Expressão gênica de Col1a1 foi diminuída em FG com DP em 6, 24 e 48h. Inibidor de MMP-9 (MMP-9i) bloqueou a expressão gênica de MMP-9 e de TGF-ß1 em FG normais e diabéticos em 24h. A expressão de col1a1 foi inibida pelo MMP-9i somente em FG normais, mas não em diabéticos. A expressão de receptor de TGF-ß do tipo 1 (TGF-ß R1) foi aumentada em FG normais e diabéticos, porém MMP-9i diminuiu esta expressão somente em FG diabéticos. Inibidor de TGF-ß (SB431542) e Dexa interromperam a expressão gênica de MMP-9, TGF-ß1 e col1a1 em FG normais e diabéticos com DP em 24h. TGF-ß R1 também foi inibido em FG normais e diabéticos com DP em 24h de tratamento com SB431542. Juntos, esses achados sugerem que indivíduos diabéticos têm síntese aumentada de TGF-ß e MMP-9 em FG durante a DP devido a ativação do TGF-ß R1 via ALK5 e presença de MMP-9. Por outro lado, o aumento na expressão de colágeno é devido a ativação de TGF-ß R1 em FG normais e diabéticos, e presença de MMP-9 em FG normais, somente(AU)

In presence of Diabetes Mellitus, periodontal disease (PD) can accentuate complication appearance and increase prevalence. The aim of this study was to evaluate whether Transforming Growth factor-ß 1 (TGF-ß1) and Matrix Metaloproteinase-9 (MMP-9) are modulating the extracellular matrix components in gingival fibroblasts (GF) from diabetic mice (D) with PD. 24 animals were divided in 4 groups then they were treated with streptozotocin to diabetes induction and DP was inducted through a ligature with silk thread. After euthanasia and gingiva harvest, mice GF were cultured. MMP-9, TGF- ß1, and type 1 Collagen (col1a1) mRNA expression and protein production were evaluated. They were also treated with MMP-9 and TGF-ß inhibitors, and dexamethasone (Dexa) for 24h. Normal and diabetic GF from PD-induced mice had increased MMP-9 and TGF-ß1 expression at 6 and 24 h decreasing at 48 h. Col1a1 gene expression was decreased in normal GF with PD at 6, 24 and 48 h. In diabetic GF col1a1 expression was inhibited at 6, 24 and 48 h. MMP-9 inhibitor (MMP-9i) blocked the MMP-9 expression, and TGF-ß1 gene expression in normal and diabetic GF at 24 h. The col1a1 gene expression was inhibited by MMP-9i only in normal GF but not in diabetic. TGF-ß R1 was increased in normal and diabetic GF with PD, but MMP9i decreased this expression only in diabetic GF. TGF-ß inhibitor (SB431542) and Dexa abrogated MMP-9, TGF-ß1 and col1a1 expression in normal and diabetic GF with PD at 24 h. TGF-ß R1 was also inhibited in normal and diabetic GF with PD after 24 h of treatment with SB431542. Taken together, these findings suggests that diabetic individuals has increased synthesis of TGF-ß and MMP-9 in GF during PD due to TGF-ß R1 activation via Alk5 and presence of MMP-9. On the other hand, increased in the col1a1 expression is due to TGF-ß R1 activation in normal and diabetic GF and presence of MMP-9 in normal GF(AU)