Abstract The objective of this in vivo study was to assess the effect of the root canal irrigation by negative and positive apical pressure on the expression of molecules that are an indicative of cell differentiation with mineralizing phenotype in teeth of dogs with incomplete rhizogenesis and induced periapical lesion. A total of 30 teeth (60 roots) were distributed into 3 groups (n=20): EndoVac®, Conventional and Control. After 90 days, the routine histotechnical procedures were performed and the sections were submitted to immunohistochemical technique for the staining of osteopontin (OPN), alkaline phosphatase (ALP) and the RUNX2 transcription factor in the apical and periapical regions of the roots. A semi-quantitative analysis of the positive immunostaining was performed and the intensity of the expression was classified in absent (0), mild (1), moderate (2), or intense (3). Scores data were statistically analyzed by the Kruskal-Wallis non-parametric test and Dunn post-test, and the significance level was set at 5%. RUNX2 immunostaining revealed that in the negative pressure group there was a significantly stronger (p<0.05) immunostaining in comparison to the control group. Regarding the OPN expression, it was not possible to detect a statistically significant difference between the groups (p>0.05). After analyzing ALP immunostaining, a statistically significant difference was observed between the groups (p<0.05), and the negative pressure group showed a markedly stronger mark immunostaining than the control group. The results of the present in vivo study allowed concluding that negative apical pressure irrigation presents mineralizing potential in immature teeth with apical periodontitis.
Resumo O objetivo do presente estudo in vivo foi avaliar o efeito da irrigação do canal radicular por pressão apical negativa e por pressão positiva na expressão de moléculas que são indicativas de diferenciação celular com fenótipo mineralizador em dentes de cães com rizogênese incompleta e lesão periapical. Um total de 30 dentes (60 raízes) foi distribuído em 3 grupos (n=20): EndoVac, Convencional e Controle. Após 30 dias, foram realizados os procedimentos histotécnicos de rotina e os cortes foram submetidos à técnica de imunohistoquímica para marcação de Osteopontina (OPN), Fosfatase Alcalina (ALP) e para o fator de transcrição RUNX2 nas regiões apical e periapical das raízes. Foi realizada uma análise semi-quantitativa da imunomarcação positiva e a intensidade da expressão foi classificada em ausente (0), leve (1), moderada (2) ou intensa (3). Os dados por escores foram analisados estatisticamente pelo teste não-paramétrico de Kruskal-Wallis e pelo pós-teste de Dunn, e o nível de significância adotado foi de 5%. A imunumarcação para RUNX2 revelou que no grupo pessão negativa houve marcação significativamente mais intensa (p<0,05), em comparação ao grupo controle. Com relação à expressão de OPN, não foi possível observer diferença estatisticamente significante entre os grupos (p>0,05). Após análise da imunomarcação para ALP, foi observado diferença estatisticamente significante entre os grupos (p<0,05), e o grupo pressão negativa demonstrou uma marcação siginificativamente mais intensa do que o grupo controle. Os resultados do presente estudo in vivo permitiram concluir que a irrigação por pressão apical negativa apresenta potencial mineralizador em dentes com ápice aberto e lesão periapical.
Abstract This study evaluated the association between polymorphisms in genes encoding estrogen receptors 1 (ESR1) and 2 (ESR2), vitamin D receptor (VDR) and in microRNA17 (which binds to ESR1 and VDR) with persistent apical periodontitis (PAP) after the endodontic treatment. We included 162 patients who completed endodontic treatment at least one year ago and presented apical periodontitis at the beginning of the root canal therapy. Clinical and radiographic exams were performed to evaluate the presence of PAP or healthy periradicular tissues (healed). Saliva samples were collected as a genomic DNA. The genotyping of ESR1 (rs2234693 and rs9340799), ESR2 (rs1256049 and rs4986938), VDR (rs739837 and rs2228570) and miRNA17 (rs4284505) were performed by real-time PCR. Chi-square test was used to the distribution of genotype and allele frequencies. Haplotype analysis was also performed. Eighty-nine patients were included in the “healed” group and 73 in the “PAP” group. No association was found between the allelic and genotypic polymorphisms studied and PAP (p>0.05). Haplotype analysis also did not demonstrated an association (p>0.05). In conclusion, the genetic polymorphisms in ESR1, ESR2, VDR and miRNA17 are not associated with PAP.
Resumo Este estudo avaliou a associação entre polimorfismos em genes que codificam os receptores de estrogênio 1 (ESR1) e 2 (ESR2), receptor de vitamina D (VDR) e no microRNA17 (que se liga à ESR1 e VDR) e a periodontite apical persistente (PAP) após o tratamento endodôntico. Foram incluídos 162 pacientes com tratamento endodôntico concluído há pelo menos um ano e que apresentavam periodontite apical no início da terapia endodôntica. Exames clínicos e radiográficos foram realizados para avaliar a presença de PAP ou tecidos perirradiculares saudáveis (cicatrizados). As amostras de saliva foram coletadas como fonte de DNA genômico. A genotipagem de ESR1 (rs2234693 e rs9340799), ESR2 (rs1256049 e rs4986938), VDR (rs739837 e rs2228570) e miRNA17 (rs4284505) foram realizadas por PCR em tempo real. O teste do qui-quadrado foi utilizado para a distribuição das frequências genotípicas e alélicas. A análise de haplótipos também foi realizada. Oitenta e nove pacientes foram incluídos no grupo “curado” e 73 no grupo “PAP”. Não foi encontrada associação entre os polimorfismos alélicos e genotípicos estudados e a PAP (p>0,05). Concluí-se que os polimorfismos genéticos em ESR1, ESR2, VDR e miRNA17 não estão associados à PAP.
Abstract The aim of this study was to evaluate the subcutaneous connective tissue response of isogenic mice after implantation of different glass ionomer-based cements (EQUIA® Forte Fil, EQUIA® Fil and Ketac™ Universal Aplicap™). Eighty-seven isogenic BALB/c mice were allocated in 12 groups, 9 were considered as experimental groups (Ketac, E. Fil and E. Forte at 7, 21 and 63 days) and 3 controls (empty polyethylene tubes at 7, 21 and 63 days). After the experimental periods, the subcutaneous connective tissue surrounding the implanted material was removed and subjected to histotechnical processing and staining with hematoxylin and eosin. A histopathological description of the tissue reaction surrounding each material and a semi-quantitative analysis of collagen fiber formation and inflammatory infiltrate were performed. Additionally, the thickness of the granulomatous tissue in contact with each material was measured. Data were analyzed statistically (α=0.05) by the Kruskal-Wallis test, followed by Dunn post-test. Initially, the collagen fiber formation was not different among all the tested materials (p>0.05) but was different at 21 days with the control group presenting the most advanced stage of collagen fiber formation. At 63 days, EQUIA® Forte Fil group showed the most advanced stage of collagen fiber formation, compared to EQUIA® Fil group (p<0.05). The inflammatory infiltrate was not different among the tested materials in any experimental period (p>0.05). The thickness of the granulomatous tissue was greater in the E. Forte group, compared to control in all periods. All glass ionomer-based cements showed tissue compatibility, according to the evaluated parameters.
Resumo O objetivo deste estudo foi avaliar a resposta subcutânea do tecido conjuntivo de camundongos isogênicos após o implante de diferentes cimentos à base de ionômero de vidro (EQUIA® Forte Fil, EQUIA® Fil e Ketac ™ Universal Aplicap ™). Oitenta e sete camundongos isogênicos BALB/c foram alocados em 12 grupos, 9 como grupos experimentais (Ketac, E. Fil e E. Forte aos 7, 21 e 63 dias) e 3 controles (tubos de polietileno vazios aos 7, 21 e 63 dias). Após os períodos experimentais, o tecido conjuntivo subcutâneo ao redor do material implantado foi removido e submetido ao processamento histotécnico e coloração com hematoxilina e eosina. Uma descrição histopatológica da reação tecidual envolvendo cada material e uma análise semi-quantitativa da fibrose e infiltrado inflamatório foram realizadas. Além disso, foi realizada a mensuração da espessura do tecido granulomatoso em contato com cada material. Os dados foram analisados estatisticamente (α=0,05) pelo teste de Kruskal-Wallis, seguido do pós-teste de Dunn. Inicialmente, a fibrose não foi diferente entre todos os materiais testados (p>0,05), mas foi diferente aos 21 dias, com o grupo controle apresentando o estágio mais avançado de fibrose. Aos 63 dias, o grupo EQUIA® Forte Fil apresentou o estágio mais avançado de fibrose, comparado ao grupo EQUIA® Fil (p<0,05). O infiltrado inflamatório não foi diferente entre os materiais testados em nenhum período experimental (p>0,05). A espessura do tecido granulomatoso foi maior no grupo E. Forte, comparado ao controle em todos os períodos. Todos os cimentos à base de ionômero de vidro apresentaram compatibilidade tecidual, de acordo com os parâmetros avaliados.
Abstract Purpose: To investigate the effects of dietary restriction on the growth plate and long bone tissue in growing rats. Methods: Sixty male Wistar rats were randomly assigned to two groups: Control (Con) and Diet-restricted (Res). After weaning, the Res rats were offered 50% of the chow ingested by the control (ad libitum food intake). The animals were subdivided into two subgroups with follow-ups up to 56 or 70 days. After euthanasia, the growth plate of tibias was analyzed by histomorphometry, micro-computed tomography, and mechanical test. The trabecular and compact bones were evaluated by histomorphometry, dual-energy X-ray absorptiometry, and micro-computed tomography (μCT). Real-time PCR was used to analyze gene expression. Results: Although dietary restriction did not alter gene expression, several phenotypic changes were seen in the growth plate; i.e., decrease in volume, reduction in total area and height, decrease in the area ossified zones, mechanical weakening, reduction in mass of trabecular and cortical bone, lower bone density, deterioration of the trabecular and cortical microarchitecture, and trabeculae with lower collagen deposition. Conclusion: Dietary restriction had severe detrimental effects on the growth plate and trabecular and cortical bone.
Abstract Purpose: To evaluate the effects of food restriction on fracture healing in growing rats. Methods: Sixty-eight male Wistar rats were assigned to two groups: (1) Control and (2) Dietary restriction. After weaning the dietary restricted animals were fed ad libitum for 42 days with 50% of the standard chow ingested by the control group. Subsequently, the animals underwent bone fracture at the diaphysis of the right femur, followed by surgical stabilization of bone fragments. On days 14 and 28 post-fracture, the rats were euthanized, and the fractured femurs were dissected, the callus was analyzed by dual-energy X-ray absorptiometry, micro-computed tomography, histomorphometry, mechanical tests, and gene expression. Results: Dietary restriction decreased body mass gain and resulted in several phenotypic changes at the bone callus (a delay in cell proliferation and differentiation, lower rate of newly formed bone and collagen deposition, reductions in bone callus density and size, decrease in tridimensional callus volume, deterioration in microstructure, and reduction in bone callus strength), together with the downregulated expression of osteoblast-related genes. Conclusion: Dietary restriction had detrimental effects on osseous healing, with a healing delay and a lower quality of bone callus formation.
Abstract Objectives Enamel demineralization is among the main topics of interest in the orthodontic field. Self-ligating brackets have been regarded as advantageous in this aspect. The aim of this study was to evaluate the break homeostasis in the oral environment and the levels of microorganisms associated with dental caries among the different types of brackets. Material and Methods Twenty patients received two self-ligating brackets: In-Ovation®R, SmartClipTM, and one conventional GeminiTM. Saliva was collected before bonding (S0), 30 (S1) and 60 (S2) days after bonding. One sample of each bracket was removed at 30 and 60 days for the in situ analysis. Checkerboard DNA-DNA Hybridization was employed to evaluate the levels of microbial species as-sociated with dental caries. Data were evaluated by nonparametric Friedman and Wilcoxon tests at 5% significance level. Results The salivary levels of L. casei (p=0.033), S. sobrinus (p=0.011), and S. sanguinis (p=0.004) increased in S1. The in situ analyses showed alteration in S. mutans (p=0.047), whose highest levels were observed to the In-Ovation®R. Conclusions The orthodontic appliances break the salivary homeostasis of microorganisms involved in dental caries. The contamination pattern was different between self-ligating and conventional brackets. The In-Ovation®R presented worse performance considering the levels of cariogenic bacterial species.
Abstract Objectives: Miniscrew has been frequently used, considering that anchorage control is a critical point in orthodontic treatment, and its failure, the main adverse problem. Using two groups of stable (successful) and unstable (failed) mini-implants, this in vivo study aimed to quantify proinflammatory cytokines IL-1 α, IL-6, IL-17, and TNF-α and osteoclastogenesis marker RANK, RANKL, and OPG in gingival tissue, using the real-time polymerase chain reaction technique. Methodology: Thirteen patients of both sexes (11-49 years old) under orthodontic treatment were selected, obtaining 11 successful and 7 failed mini-implants. The mini-implants were placed and removed by the same surgeon, in both jaws. The mean time of permanence in the mouth was 29.4 months for successful and 7.6 months for failed mini-implants. At removal time, peri-mini-implant gingival tissue samples were collected and processed for quantification of the proinflammatory cytokines and osteoclastogenesis markers. Nonparametric Wilcoxon rank-sum test considering the clusters and Kruskal-Wallis test were used for statistical analysis (α=0.05). Results: No significant difference (p>0.05) was observed between the groups for either quantification of cytokines or osteoclastogenesis markers, except for IL-6 (p<0.05). Conclusions: It may be concluded that the expression of IL-1α, IL-17, TNF-α, RANK, RANKL, and OPG in peri-implant gingival tissue were not determinant for mini-implant stability loss, but the higher IL-6 expression could be associated with mini-implant failure.
Abstract This study evaluated the effect of antimicrobial photodynamic therapy (aPDT) on the endodontic treatment of apical periodontitis (AP). AP was induced in 48 premolars of 6 dogs. After biomechanical preparation, the teeth were divided into 4 groups: Calcium-Hydroxide (CH)/120d and CH/180d: root canals filled with CH-based dressing for 15 days before obturation; aPDT/120d and aPDT/180d: conditioning with phenothiazine photosensitizer (10 mg/mL) for 1 minute and irradiation with diode laser in the same session as obturation. Root filling was performed with AH Plus sealer. After the experimental periods, animals were euthanized and teeth were submitted for histology. HE staining was performed for descriptive analysis of the periapical region, measurement of apical periodontitis and for inflammatory cells, and blood vessels count. Immunohistochemistry was performed for osteopontin (OPN) and alkaline phosphatase (ALP). Data were analyzed statistically by two-way ANOVA and chi-square test (α = 5%). Teeth in Group CH/120d presented only a slightly enlarged periodontal ligament (PL) with advanced repair. Group aPDT/120d presented the PL moderately enlarged, with moderate inflammatory infiltrate and few collagen fibers. The same pattern was observed at 180 days. AP lesions in CH-treated groups were smaller than those in aPDT-treated groups (p < 0.001) with more blood vessels (p < 0.0001), regardless of the evaluation period, without significant differences in the number of inflammatory cells (p > 0.05). CH-treated groups showed significantly more intense immunostaining for ALP and OPN (p < 0.001) in both periods. Although aPDT stimulated angiogenesis and expression of bone formation markers, the two-session endodontic treatment with CH-based dressing promoted better apical periodontitis repair.
Abstract The aim of this study was to evaluate the association between timing of permanent tooth emergence with overweight and obesity in children from Brazilian Amazon region. The studied population consisted of 192 children, 09 to 12 year-old, from public schools at Manaus, Amazonas-Brazil. Clinical examination was performed and the tooth emergence was evaluated according to the number of permanent erupted teeth. Body mass index z-score was calculated. For the statistical analysis ‘Overweight/obese’ group was compared with ‘Normal weight’ group in a case to control ratio 1:2. The t-test based on age was used for means comparison between the groups. A linear regression analysis using age and gender as co-variants was used. The established alpha was 5%. One hundred twenty-seven children were classified as normal weight and 65 were classified as overweight/obese (49 were overweight and 16 were obese). Overweight/obesity condition was associated with the gender, in which boys had a higher chance to present higher weight conditions (OR=1.84; CI 95% 1.06-3.37; p=0.04). The mean number of permanent teeth was higher in the overweight/obesity group (p<0.001). Linear regression analysis demonstrated that nutritional status, gender and age were strongly associated with number of permanent erupted teeth (p<0.05). In conclusion, our study demonstrated that timing of permanent tooth emergence is associated with overweigh/obesity in children from Manaus, Brazil.
Resumo O objetivo deste estudo foi avaliar se a erupção dentária está associada com sobrepeso/obesidade em crianças da região Amazônica brasileira. A população estudada foi composta por 192 crianças, de 9 a 12 anos, de escolas públicas de Manaus, Amazonas-Brasil. O exame clínico foi realizado e a erupção dentária foi avaliada de acordo com o número de dentes permanentes irrompidos. O índice de massa corporal escore-z foi calculado. Para a análise estatística, comparou-se o grupo "sobrepeso / obesidade" com o grupo "peso normal" em uma proporção de controle 1: 2. O teste t baseado na idade foi utilizado para comparação das médias entre os grupos. Uma análise de regressão linear usando idade e sexo como co-variáveis foi utilizada. O alfa estabelecido foi de 5%. Cento e vinte e sete crianças foram classificadas com peso normal e 65 foram classificados com sobrepeso / obesidade (49 com sobrepeso e 16 com obesidade). A condição de sobrepeso / obesidade associou-se ao gênero, no qual os meninos tiveram maior chance de apresentar condições de maior peso (OR = 1,84; IC 95% 1,06-3,37; p = 0,04). O número médio de dentes permanentes irrompidos foi maior no grupo sobrepeso / obesidade (p <0,001). A análise de regressão linear demonstrou que o estado nutricional, sexo e idade foram fortemente associados ao número de dentes permanentes irrompidos (p <0,05). Concluindo, nosso estudo demonstrou que o momento da erupção dos dentes permanentes é associado com sobrepeso / obesidade em crianças de Manaus, Brasil.
Abstract Persistent apical periodontitis (AP) is a situation involving an inflammatory and immune response caused mainly by anaerobic polymicrobial infection of the root canal system and the outcome and follow-up of the root canal treatment has been reported as intimately related to host response. The apical periodontitis repair might be associated with genetic polymorphisms. This study aimed to evaluate the association between HIF1A genetic polymorphisms (rs2301113 and rs2057482) with PAP in Brazilian patients. Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Sixty-four subjects with signs/symptoms of PAP and 84 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for HIF1A genotyping by real-time PCR. Genotype and allele frequencies were compared by c2 or Fisher’s exact tests and odds ratio was implemented, using Epi Info 3.5.2. All tests were performed with an established alpha of 0.05. There was no association between allele and genotype distribution for HIF1As polymorphisms and PAP (p>0.05). The genetic polymorphisms in HIF1A were not associated with persistent apical periodontitis.
Resumo A periodontite apical persistente (PAP) é uma condição que envolve uma resposta inflamatória e imunológica causada principalmente por infecções polimicrobianas de origem anaeróbia no sistema de canais radiculares, tornando o resultado e o acompanhamento do tratamento do canal radicular intimamente relacionados à resposta do hospedeiro. O reparo da periodontite apical pode estar associado a polimorfismos genéticos. Este estudo teve como objetivo avaliar a associação entre os polimorfismos genéticos do HIF1A (rs2301113 e rs2057482) com a PAP em pacientes brasileiros. Indivíduos com pelo menos 1 ano de acompanhamento após o tratamento do canal radicular (TCR) foram agendados para consulta de acompanhamento. Sessenta e quatro indivíduos com sinais/sintomas de PAP e 84 indivíduos com dentes tratados endodonticamente e tecidos perirradiculares saudáveis (cicatrizados) foram incluídos no presente estudo. O DNA genômico foi extraído da saliva e utilizado para a genotipagem do HIF1A por PCR em tempo real. O genótipo e as frequências alélicas foram comparados por teste c2 ou exato de Fisher e odds-ratio foi implementado por meio do software Epi Info 3.5.2. Todos os testes realizados foram estabelecidos com a=0,05. Não houve associação entre alelo e distribuição genotípica para polimorfismos do HIF1A e PAP (p> 0,05). Os polimorfismos genéticos em HIF1A não foram associados à periodontite apical persistente.
Abstract The aim of this study was to evaluate the expression of MMP2 and MMP9 during apical periodontitis (AP) progression in TLR2 (TLR2 KO) and in MyD88 (MyD88 KO) knockout mice compared to wild type (WT) mice. AP was induced in mandibular first molars of TLR2 KO (n= 18), MyD88 KO (n= 18), and WT mice (n= 18). After 7, 21, and 42 days, the animals were euthanized and the jaws were dissected and subjected to histotechnical processing. Subsequent sections were stained by immunohistochemistry and evaluated for detection of MMP2 and MMP9. Statistical analysis of the semi-quantitative analysis of immunohistochemistry was performed using chi-square test (α = 0.05). In the initial periods of AP progression, an increased expression of MMP9 in the TLR2 KO and MyD88 KO mice was observed. In the final periods of AP progression, a reduction of MMP2 expression and an increase of MMP9 expression in the TLR2 KO mice were observed. MMP2 and MMP9 production was modulated for TLR2 and MyD88 during apical periodontitis progression.
Resumo O objetivo deste estudo foi avaliar a expressão de MMP2 e MMP9 durante a progressão da periodontite apical (AP) em camundongos knockout para TLR2 (TLR2 KO) e MyD88 (MyD88 KO) comparados aos camundongos wild type (WT). A AP foi induzida nos primeiros molares inferiores dos camundongos TLR2 KO (n = 18), MyD88 KO (n = 18) e WT (n = 18). Após 7, 21 e 42 dias, os animais foram eutanaziados e as mandíbulas foram dissecadas e submetidas a processamento histotécnico. As lâminas foram coradas por imuno-histoquímica e analisadas para a detecção de MMP2 e MMP9. A análise estatística semi-quantitativa da imuno-histoquímica foi realizada pelo teste qui-quadrado (α = 0,05). Nos períodos iniciais de progressão AP, foi observada uma expressão aumentada de MMP9 nos camundongos TLR2 KO e MyD88 KO. Nos períodos finais de progressão AP, observou-se uma redução da expressão de MMP2 e um aumento da expressão de MMP9 nos camundongos TLR2 KO. A produção de MMP2 e MMP9 foi modulada por TLR2 e MyD88 durante a progressão da periodontite apical.
Abstract Objective To evaluate and correlate, in the same research, the mRNA expression and the staining of RANK, RANKL, OPG, TLR2 and MyD88 by immunohistochemistry in the apical periodontitis (AP) progression in mice. Material and Methods AP was induced in the lower first molars of thirty-five C57BL/6 mice. They were assigned to four groups according to their euthanasia periods (G0, G7, G21 and G42). The jaws were removed and subjected to histotechnical processing, immunohistochemistry and real-time reverse transcription-PCR (qRT-PCR). Data were analyzed with parametric and nonparametric tests (α=0.05). Results An increase of positive immunoreactivity for RANK, RANKL, OPG, TLR2 and MyD88 was observed over time (p<0.05). The RANKL expression was different between the groups G0 and G42, G21 and G42 (p=0.006), with G42 presenting the higher expression in both comparations. The OPG expression was statistically different between the groups G0 and G7, G7 and G21 and G7 and G42 (p<0.001), with G7 presenting higher expression in all the time points. The TLR2 expression was different between the groups G0 and G42 (p=0.03), with G42 showing the higher expression. The MyD88 expression presented a statistical significant difference between groups G7, G21 and G42 compared with G0 (p=0.01), with G0 presenting the smallest expression in all the comparisons. The Tnfrsf11/Tnfrsf11b (RANKL/OPG) ratio increased with the AP progression (p=0.002). A moderate positive correlation between MyD88 and RANKL (r=0.42; p=0.03) and between MyD88 and TLR2 (r=0.48; p<0.0001) was observed. Conclusion The expression of the RANK, RANKL, OPG, MyD88 and TLR2 proteins as well as the ratio Tnfrsf11/Tnfrsf11b (RANKL/OPG) increased with AP progression. There was also a moderate positive correlation between the expression Myd88-Tnfrsf11 and Tlr2-Myd88, suggesting the relevance of Tlr2-Myd88 in bone loss due to bacterial infection.
Abstract Objectives Using two groups of mini-implants (successful and failed) the objectives of this in vivo study were: to evaluate the microbial contamination by the checkerboard DNA-DNA hybridization technique and to quantify the bacterial endotoxin by the limulus amebocyte lysate assay. Material and Methods The 15 successful and 10 failed mini-implants (1.6 mm diameter × 7.0 or 9.0 mm long), placed in the maxilla and/or mandible, were obtained from 15 patients undergoing orthodontic treatment. Data were analyzed statistically by the Wilcoxon rank-sum test using the SAS software (a=0.05). Results All 40 microbial species were detected in both groups of mini-implants, with different frequencies. No differences were observed between the groups with respect to microbial complexes (blue, purple, yellow, green, orange, red and other species) and endotoxin quantification (p>0.05). Conclusion Neither microbial contamination nor endotoxin quantification was determinant for the early loss of stability of the mini-implants.
Abstract Aim: To compare the apical negative pressure irrigation (ANP) with conventional irrigation in the teeth of immature dogs with apical periodontitis. Methods: Fifty-two immature pre-molar root canals were randomly assigned into 4 groups: ANP (n=15); conventional irrigation (n=17); healthy teeth (control) (n = 10); and teeth with untreated apical periodontitis (control) (n=10). After induction of apical periodontitis, teeth were instrumented using EndoVac® (apical negative pressure irrigation) or conventional irrigation. The animals were euthanized after 90 days. The sections were stained by HE and analyzed under conventional and fluorescence microscopy. TRAP histoenzymology was also performed. Statistical analyses were performed with the significance level set at 5%. Results: There was difference in the histopathological parameters between ANP and conventional groups (p<0.05). The ANP group showed a predominance of low magnitude inflammatory infiltrate, a smaller periodontal ligament, and lower mineralized tissue resorption. There were no differences in the periapical lesion extensions between the ANP and conventional groups (p>0.05). However, a lower number of osteoclasts was observed in the ANP group (p<0.05). Conclusion: The EndoVac® irrigation system presented better biological results and more advanced repair process in immature teeth with apical periodontitis than the conventional irrigation system, confirming the hypothesis.
Abstract Bacterial endotoxin (LPS) adhesion to orthodontic brackets is a known contributing factor to inflammation of the adjacent gingival tissues. Objective The aim of this study was to assess whether LPS adheres to orthodontic adhesive systems, comparing two commercial brands. Material and Methods Forty specimens were fabricated from Transbond XT and Light Bond composite and bonding agent components (n=10/component), then contaminated by immersion in a bacterial endotoxin solution. Contaminated and non-contaminated acrylic resin samples were used as positive and negative control groups, respectively. LPS quantification was performed by the Limulus Amebocyte Lysate QCL-1000™ test. Data obtained were scored and subjected to the Chi-square test using a significance level of 5%. Results There was endotoxin adhesion to all materials (p<0.05). No statistically significant difference was found between composites/bonding agents and acrylic resin (p>0.05). There was no significant difference (p>0.05) among commercial brands. Affinity of endotoxin was significantly greater for the bonding agents (p=0.0025). Conclusions LPS adhered to both orthodontic adhesive systems. Regardless of the brand, the endotoxin had higher affinity for the bonding agents than for the composites. There is no previous study assessing the affinity of LPS for orthodontic adhesive systems. This study revealed that LPS adheres to orthodontic adhesive systems. Therefore, additional care is recommended to orthodontic applications of these materials.