Abstract Objectives: Dental composites release unreacted resin monomers into the oral environment, even after polymerization. Periodontal cells are, therefore, exposed to substances that potentially elicit the immune inflammatory response. The underlying molecular mechanisms associated with the interaction between resin monomers and human immune cells found in the gingival crevicular fluid are not fully understood yet. This study investigated the ability of bisphenol A-glycidyl methacrylate (BISGMA), urethane dimethacrylate (UDMA) and triethylene glycol dimethacrylate (TEGDMA) to induce apoptosis and cytokine release by human leukocytes stimulated with a periodontal pathogen. Methodology: Peripheral blood mononuclear cells (PBMC) from 16 healthy individuals were included in this study. To determine the toxicity, the PBMC were incubated for 20 hours, with monomers, for the analysis of cell viability using MTT assay. To evaluate cell death in the populations of monocytes and lymphocytes, they were exposed to sub-lethal doses of each monomer and of heat-inactivated Porphyromonas gingivalis (P. gingivalis) for 5 hours. Secretions of IL-1β, IL-6, IL-10 and TNF-α were determined by ELISA after 20 hours. Results: UDMA and TEGDMA induced apoptosis after a short-time exposure. Bacterial challenge induced significant production of IL-1β and TNF-α (p<0.05). TEGDMA reduced the bacterial-induced release of IL-1β and TNF-α, whereas UDMA reduced IL-1β release (p<0.05). These monomers did not affect IL-10 and IL-6 secretion. BISGMA did not significantly interfere in cytokine release. Conclusions: These results show that resin monomers are toxic to PBMC in a dose-dependent manner, and may influence the local immune inflammatory response and tissue damage mechanisms via regulation of bacterial-induced IL-1β and TNF-α secretion by PBMC.
ABSTRACT: The objective of this study was to verify the influence of the use of Class II intermaxillary elastics on centric relation (CR) to centric occlusion (CO) occlusal discrepancy. A total of 30 patients had been at the contention stage for at least three months were divided in two groups: G1 - 15 had been submitted to intramaxillary orthodontic mechanics only, and G2 - 15 had used Class II intermaxillary elastics. Distances of horizontal and vertical overlap and the distance or coincidence of the mandibular dental midline in relation to the maxillary midline were measured in CR and CO positions. Intergroup comparisons were performed using the Mann-Whitney test. No statistically significant differences (P>0.05) were found between G1 and G2. Both in the horizontal and vertical directions, these discrepancies were smaller than or equal to 1mm in 96.66 % of the patients. In the transverse plane, there was no discrepancy in 63.33 % of the patients, and in 33.33 % these discrepancies were equal to 0.5 mm. The use of Class II elastic didn't be capable of increasing the occlusal discrepancies between CR and CO.
RESUMEN: El objetivo de este estudio fue verificar la influencia del uso de los elásticos intermaxilares Clase II en la discrepancia oclusal entre la relación céntrica (RC) y la oclusión céntrica (OC). Un total de 30 pacientes que permanecieron en la fase de contención durante al menos tres meses se dividieron en dos grupos: G1 - 15 fueron sometidos solamente a la mecánica ortodóncica intramaxilar, y G2 - 15 habían utilizado elásticos de clase II intermaxilar. Se midieron las distancias de traslapo horizontal y vertical y la distancia o coincidencia de la línea mediana dentaria mandibular con respecto a la línea mediana maxilar en las posiciones RC y OC. Las comparaciones entre grupos se realizaron mediante la prueba de Mann-Whitney. No se encontraron diferencias estadísticamente significativas (P> 0.05) entre G1 y G2. Tanto en las direcciones horizontal como vertical, estas discrepancias fueron menores o iguales a 1 mm en el 96,66 % de los pacientes. En el plano transversal, no hubo discrepancia en el 63,33 % de los pacientes, y en un 33,33 % estas discrepancias fueron iguales a 0,5 mm. El uso de la clase II elástica no logró aumentar las discrepancias entre RC y OC.
ABSTRACT Objective: The aim of this study was to evaluate the skeletal and dental effects of rapid maxillary expansion (RME) in cleft patients using two types of expanders. Methods: Twenty unilateral cleft lip and palate patients were randomly divided into two groups, according to the type of expander used: (I) modified Hyrax and (II) inverted Mini-Hyrax. A pretreatment cone-beam computed tomographic image (T0) was taken as part of the initial orthodontic records and three months after RME, for bone graft planning (T1). Results: In general, there was no significant difference among groups (p > 0.05). Both showed a significant transverse maxillary expansion (p < 0.05) and no significant forward and/or downward movement of the maxilla (p > 0.05). There was greater dental crown than apical expansion. Maxillary posterior expansion tended to be larger than anterior opening (p < 0.05). Cleft and non-cleft sides were symmetrically expanded and there was no difference in dental tipping between both sides (p > 0.05). Conclusions: The appliances tested are effective in the transverse expansion of the maxilla. However, these appliances should be better indicated to cleft cases also presenting posterior transverse discrepancy, since there was greater expansion in the posterior maxillary region than in the anterior one.
RESUMO Objetivo: o objetivo deste estudo foi avaliar os efeitos esqueléticos e dentários da expansão rápida da maxila (ERM) em pacientes fissurados, utilizando dois tipos de disjuntores. Métodos: vinte pacientes com fissura labiopalatal unilateral foram aleatoriamente divididos em dois grupos, de acordo com o tipo de aparelho utilizado: (1) Hyrax modificado e (2) Mini-Hyrax invertido. Tomografias computadorizadas de feixe cônico foram obtidas antes do tratamento (T0), como parte da documentação ortodôntica inicial, e três meses após a ERM, para o planejamento de enxertia óssea (T1). Resultados: não houve diferença significativa entre os grupos (p>0,05). Ambos apresentaram significativa expansão transversal da maxila (p<0,05), sem significativa movimentação anterior e/ou inferior da maxila (p>0,05). Houve uma maior expansão transversal das coroas em relação à expansão nos ápices. A tendência observada foi uma maior expansão na região posterior da maxila, em comparação à anterior (p<0,05). Avaliando o deslocamento dos lados fissurado e não fissurado, a expansão ocorreu de maneira simétrica e não houve diferença na inclinação dentária entre os lados (p>0,05). Conclusões: os aparelhos testados são eficazes na expansão transversal da maxila em pacientes fissurados. Porém, esses aparelhos seriam melhor indicados para casos de fissura labiopalatal com atresia transversal posterior, uma vez que a expansão foi maior na região posterior da maxila do que na região anterior.
Abstract: The aim of this study was to evaluate the filling effectiveness and dentinal penetration of the sealers AH Plus, Pulp Canal Sealer EWT, Sealapex and MTA Fillapex applied according to the vertical condensation technique using thermoplastic gutta-percha. Forty single-rooted teeth were selected. After chemical-mechanical preparation and root-canal filling, sections of the root (2, 4 and 6 mm from the apex) were obtained and analyzed by stereo microscopy and confocal laser scanning microscopy. Data were tabulated and statistically analyzed. With regard to the assessment of void spaces in the filling material at 2 mm from the apex, the sealers showed similar results, but at 4 and 6 mm from the apex, MTA Fillapex had inferior performance compared to AH Plus (at 4 mm), Pulp Canal Sealer EWT (at 4 and 6 mm) and Sealapex (at 6 mm) (p<0.05). With regard to the penetration into dentinal tubules at 2 mm from the apex, the sealers also showed similar results, but at 4 and 6 mm Pulp Canal Sealer EWT had an inferior performance compared to MTA Fillapex and AH Plus, respectively (p<0.05). All four sealers were found to be similar regarding adaptation of the filling material to the root canal walls, except the MTA Fillapex, which showed failures at 4 and 6 mm from the root apex. With regard to the ability to penetrate into the dentinal tubules, the sealers were found to be equivalent, except for the Pulp Canal Sealer EWT as it had poorer results at 4 and 6 mm compared to MTA Fillapex and AH Plus, respectively.
Resumo: O objetivo deste estudo foi avaliar a efetividade da obturação e capacidade de penetração no interior dos túbulos dentinários dos cimentos: AH Plus, Pulp Canal Sealer EWT, Sealapex e MTA Fillapex, associado à técnica de obturação da condensação vertical da guta-percha termoplastificada. Selecionou-se 40 dentes unirradiculados. Após o preparo químico-mecânico e obturação, secções das raízes (a 2, 4 e 6 mm do ápice) foram obtidas e analisadas através de microscopia estéreo e confocal de varredura a laser. Os dados foram tabulados e analisados estatisticamente. Em relação à avaliação de espaços vazios na obturação a 2 mm, os cimentos apresentaram resultados similares, entretanto a 4 e 6 mm MTA Fillapex apresentou desempenho inferior em relação a AH Plus (a 4 mm), Pulp Canal Sealer EWT (a 4 e 6 mm) e Sealapex (a 6 mm) (p<0,05). Em relação à capacidade de penetração nos túbulos dentinários a 2 mm, os cimentos apresentaram resultados similares, contudo a 4 e 6 mm, o Pulp Canal Sealer EWT mostrou-se inferior ao MTA Fillapex e AH Plus, respectivamente (p<0,05). Os quatro cimentos foram similares em relação à adaptação da obturação nas paredes dos canais radiculares, exceto o MTA Fillapex, que evidenciou falhas a 4 e 6 mm. Na capacidade de penetração nos túbulos dentinários, os cimentos foram equivalentes, exceto o Pulp Canal Sealer EW que se mostrou inferior a 4 e 6 mm, quando comparado com MTA Fillapex e AH Plus, respectivamente.
Oral squamous cell carcinoma (OSCC) is one of the most common malignances. In epithelial-mesenchymal transition (EMT), epithelial cells switch to mesenchymal-like cells exhibiting high mobility. This migratory phenotype is significant during tumor invasion and metastasis. Objective : The aim of this study is to evaluate the expression of the EMT markers E-cadherin, N-cadherin and vimentin in OSCC. Material and Methods : Immunohistochemical detection of E-cadherin, N-cadherin and vimentin was performed on 20 OSCC samples. Differences in the expression of each protein at the invasive front (IF) and in the central/superficial areas (CSA) of the tumor were assessed. Differences in the expression of each protein at the IF of both histologically high- and low-invasive OSCCs were evaluated. Associations among expression of proteins at the IF were assessed. Correlations between the expression levels of each protein at the IF and the tumor stage and clinical nodal status were also evaluated. Results : Reduced expression of E-cadherin was detected in 15 samples (75%). E-cadherin expression was reduced at the IF when compared to the CSA and in high-invasive tumors when compared to low-invasive tumors. All samples were negative for N-cadherin, even though one sample showed an inconspicuous expression. Positive expression of vimentin was observed in 6 samples (30%). Nevertheless, there was no difference in vimentin expression between the IF and the CSA regions or between the low- and high-invasive tumors. Furthermore, no association was observed among protein expression levels at the IF. Finally, no correlations were observed between each protein’s expression levels and tumor stage or clinical nodal status. Conclusions : Reduced E-cadherin expression at the IF and its association with histological invasiveness suggest that this protein is a noteworthy EMT marker in OSCC. Although vimentin was also detected as an EMT marker, its expression was neither limited to the IF nor was it related to histological invasiveness.
Objective: The aim of this article was to assess how intraoral biodegradation influenced the surface characteristics and friction levels of metallic brackets used during 12 and 24 months of orthodontic treatment and also to compare the static friction generated in these brackets with four different methods of the ligation of orthodontic wires. Material and Methods: Seventy premolar brackets as received from the manufacturer and 224 brackets that were used in previous orthodontic treatments were evaluated in this experiment. The surface morphology and the composition of the deposits found in the brackets were evaluated with rugosimetry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Friction was analyzed by applying tensile tests simulating sliding mechanics with a 0.019x0.025" steel wire. The static friction levels produced by the following ligation methods were evaluated: loosely attached steel ligature around all four bracket wings, steel ligature attached to only two wings, conventional elastomeric ligation around all 4 bracket wings, and non-conventional Slide® elastomeric ligature. Results: The results demonstrated the presence of biodegradation effects such as corrosion pits, plastic deformation, cracks, and material deposits. The main chemical elements found on these deposits were Carbon and Oxygen. The maximum friction produced by each ligation method changed according to the time of intraoral use. The steel ligature loosely attached to all four bracket wings produced the lowest friction levels in the new brackets. The conventional elastic ligatures generated the highest friction levels. The metallic brackets underwent significant degradation during orthodontic treatment, showing an increase in surface roughness and the deposit of chemical elements on the surface. Conclusion: The levels of static friction decreased with use. The non-conventional elastic ligatures were the best alternative to reduce friction.
The aim of this study was to evaluate the effects of deproteinization with 5.25% sodium hypochlorite (NaOCl) prior to enamel conditioning with 10% polyacrylic acid (PAA) and 35% phosphoric acid (PA) on the bond strength (BS) of brackets bonded with resin-modified glass ionomer cement (RMGIC). One hundred human premolars extracted for orthodontic reasons were divided into 5 groups (n = 20 in each group): G1 (control), enamel conditioning with PA, application of adhesive and bonding of brackets with TransbondTM XT composite resin (3M/Unitek, Monrovia, CA, USA); G2, enamel conditioning with PAA and bonding with RMGIC (Fuji OrthoTM LC, GC America, Alsip, IL, USA); G3, NaOCl-treated enamel, conditioning with PAA and bonding with RMGIC; G4, enamel conditioning with PA and bonding with RMGIC; and G5, NaOCl-treated enamel, conditioning with PA and bonding with RMGIC. Once the brackets were bonded, the teeth were stored in distilled water for 24 hours at room temperature and pressure until being subjected to shear stress in a Universal Mechanical Testing Machine (EMIC® DL 500, São José dos Pinhais, PR, Brazil). The BS value was higher in G1 (17.08 ± 6.39) than in any of the experimental groups (p < 0.05). No statistically significant differences were noted between groups using RMGIC (p > 0.05), except between G3 (9.86 ± 2.90) and G5 (5.00 ± 2.49). No statistically significant differences were noted between the mean Adhesive Remnant Index values among the evaluated groups (p > 0.05). Conclusion: The use of NaOCl combined with PAA increased the BS of brackets bonded with RMGIC. The deproteinization of the group treated with PA reduced the shear bond strength of the brackets.
OBJECTIVE: To compare the static frictional forces generated at the bracket/wire interface of stainless steel brackets with different geometries and angulations, combined with orthodontic wires of different diameters. MATERIAL AND METHODS: The frictional forces were evaluated with three different types of metal brackets: a passive self-ligating (SmartClipTM, 3M/Unitek, Monrovia, USA), with a modified slot design (Mini Uni TwinTM, 3M/Unitek, Monrovia, USA) and conventional (Kirium, Abzil, São José do Rio Preto, Brazil). The samples were mounted in a testing device with three different angulations and tested with 0.014" and 0.018" stainless steel wires (American Orthodontics, Sheboygan, USA). The static frictional force was measured using a universal testing machine (DL 500, EMIC®, São José dos Pinhais, Brazil) with a crosshead speed of 1 mm/min. Statistical analysis was performed by two-way ANOVA followed by Bonferroni's post hoc test. RESULTS: There was a significant difference (p<0.05) in static friction when the three types of brackets were tested with the same wire size. The wire diameter influenced friction only when the brackets had a 10º angulation (p<0.05). The angulation influenced friction (p<0.05) when the brackets were associated with a 0.018" wire. CONCLUSION: Brackets with a modified slot design showed intermediate static frictional force values between the conventional and self-ligating brackets tested.
Focal reactive overgrowths are among the most common oral mucosal lesions. The gingiva is a significant site affected by these lesions, when triggered by chronic inflammation in response to microorganisms in dental plaque. Myofibroblasts are differentiated fibroblasts that actively participate in diseases characterized by tissue fibrosis. The objective of this study was to evaluate the presence of stromal myofibroblasts in the main focal reactive overgrowths of the gingiva: focal fibrous hyperplasia (FFH), peripheral ossifying fibroma (POF), pyogenic granuloma (PG), and peripheral giant cell granuloma (PGCG). A total of 10 FFHs, 10 POFs, 10 PGs, and 10 PGCGs from archival specimens were evaluated. Samples of gingival mucosa were used as negative controls for stromal myofibroblasts. Oral squamous cell carcinoma samples, in which stromal myofibroblasts have been previously detected, were used as positive controls. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin (α-sma). Myofibroblast immunostaining was qualitatively classified as negative, scanty, or dense. Differences in the presence of myofibroblasts among FFH, POF, PG, and PGCG were analyzed using the Kruskal-Wallis test. Stromal myofibroblasts were not detected in FFH, POF, PG, or PGCG. Consequently, no differences were observed in the presence of myofibroblasts among FFH, POF, PG, or PGCG (p > 0.05). In conclusion, stromal myofibroblasts were not detected in the focal reactive overgrowths of the gingiva that were evaluated, suggesting that these cells do not play a significant role in their pathogenesis.
A high proliferative activity of the odontogenic epithelium in ameloblastoma (AM) and keratocystic odontogenic tumor (KOT) has been demonstrated. However, no previous study has simultaneously evaluated cell proliferation and apoptotic indexes in AM and KOT, comparing both lesions. The aim of this study was to assess and compare cell proliferation and apoptotic rates between these two tumors. Specimens of 11 solid AM and 11 sporadic KOT were evaluated. The proliferation index (PI) was assessed by immunohistochemical detection of Ki-67 and the apoptotic index (AI) by methyl green-pyronine and in situ DNA nick end-labelling methods. KOT presented a higher PI than AM (p<0.05). No statistically significant difference was found in the AI between AM and KOT. PI and AI were higher in the peripheral cells of AM and respectively in the suprabasal and superficial layers of KOT. In conclusion, KOT showed a higher cell proliferation than AM and the AI was similar between these tumors. These findings reinforce the classification of KOT as an odontogenic tumor and should contribute to its aggressive clinical behavior.
Uma elevada atividade proliferativa do epitélio odontogênico em ameloblastoma (AM) e tumor odontogênico ceratocístico (TOC) tem sido demonstrada. Entretanto, não há estudos prévios avaliando simultaneamente os índices de proliferação celular e apoptótico em AM e TOC, comparando ambas as lesões. O objetivo desse estudo foi avaliar e comparar os índices de proliferação celular e apoptótico entre esses dois tumores. Onze amostras deAM sólido e 11 amostras de TOC esporádico foram avaliadas. O índice de proliferação celular foi avaliado por meio da imunomarcação para o antígeno Ki-67 e o índice apoptótico pelas técnicas demetyl-green-pironina e TUNEL. O TOC apresentou um índice de proliferação celular maior que o AM (p<0,05). Nenhuma diferença estatística foi encontrada no índice apoptótico entre AM e TOC. Os índices de proliferação celular e apoptótico foram maiores nas células da camada periférica do AM e, respectivamente, nas camadas suprabasal e superficial do TOC. Em conclusão, o TOC apresentou proliferação celular maior que o AM e o índice apoptótico foi similar entre estes tumores. Estes achados reforçam a classificação do TOC como um tumor odontogênico e podem contribuir para o seu comportamento clínico agressivo.
PURPOSE: To report a case of cemental tear, a rare periodontal condition characterized by total or partial separation of the dental cementum, mainly addressing issues related to its diagnosis and treatment. CASE DESCRIPTION: A 50 years-old man sought dental assistance complaining of pain located in the mandibular left second premolar that showed a 4 mm probing depth with the presence of a foreign body in the distal gingival sulcus. Radiographic examination demonstrated a slight radiopaque fragment detached from the root. The fragment was removed without a periodontal flap. Histopathological examination was performed and evidenced the presence of a cementum fragment with cementum lamellae, cementocytes, and adhered periodontal ligament fibers, confirming the diagnosis of cemental tear. CONCLUSION: After a follow-up of 2 years, the nonsurgical periodontal therapy showed satisfactory clinical and radiographic outcome. Therefore, this approach should be a suitable and predictable treatment modality for the cemental tear.
OBJETIVO: Relatar um caso de dilaceração cementária, uma condição periodontal rara caracterizada pela separação total ou parcial do cemento dental, abordando principalmente aspectos relativos ao seu diagnóstico e tratamento. DESCRIÇÃO DO CASO: Um homem de 50 anos procurou assistência odontológica queixando-se de dor localizada no segundo molar inferior que apresentava profundidade de sondagem de 4 mm com presença de um corpo estranho no sulco gengival da face distal. O exame radiográfico demonstrou um fragmento radiopaco destacado da raiz. O fragmento foi removido sem cirurgia periodontal. O exame histopatológico demonstrou tratar-se de um fragmento de cemento com presença de lamelas cementárias, cementócitos e fibras do ligamento periodontal, confirmando o diagnóstico de dilaceração cementária. CONCLUSÃO: Após dois anos, o tratamento periodontal não cirúrgico demonstrou aspectos clínicos e radiográficos satisfatórios. Portanto, a terapia periodontal não cirúrgica pode ser uma modalidade de tratamento adequada e previsível para a dilaceração cementária.
Dental biofilm control represents a basic procedure to prevent caries and the occurrence of periodontal diseases. Currently, toothbrushes and dentifrices are used almost universally, and the employment of good oral hygiene allows for appropriate biofilm removal by both mechanical and chemical control. The aim of this study was to evaluate the effectiveness of adding vegetable or mineral oil to a commercially available dentifrice in dental biofilm control. A comparison using the Oral Hygiene Index Simplified (OHI-S) was performed in 30 individuals who were randomly divided into three groups. Group 1 (G1) received a commercially available dentifrice; the composition of this dentifrice was modified by addition of mineral oil (Nujol®) for group 2 (G2) or a vegetable oil (Alpha Care®) for group 3 (G3) at 10% of the total volume, respectively. The two-way repeated-measures analysis of variance (two-way ANOVA) was used to test the effect of group (G1, G2 and G3) or time (baseline, 45 days and 90 days) on the OHI-S index scores. Statistical analysis revealed a significant reduction in the OHI-S at day 90 in G2 (p < 0.05) and G3 (p < 0.0001) in comparison to G1. Therefore, the addition of a vegetable or a mineral oil to a commercially available dentifrice improved dental biofilm control, suggesting that these oils may aid in the prevention and/or control of caries and periodontal disease.
The purpose of the present investigation was to compare the presence of Epstein-Barr virus type 1 (EBV-1) and of Human Cytomegalovirus (HCMV) in crevicular fluid samples from deep and shallow periodontal pocket sites of Brazilian patients with aggressive periodontitis. A total of 30 systemically healthy patients with aggressive periodontitis participated in the study. Paper points were inserted into 2 gingivitis sites (< 3 mm) and into 2 periodontitis sites (> 5 mm) in each patient. PCR assay was used to identify genomic copies of HCMV and EBV-1. Twenty-three patients (77%) were positive for EBV-1, while only 2 patients (6%) were positive for HCMV. The McNemar test revealed a positive association between EBV-1 and periodontal lesions (p = 0.043). Thirty-four (57%) out of 60 periodontitis sites were positive for EBV-1, whereas 18 (30%) gingivitis sites were positive (p = 0.01). Only two sites (6.7%) were positive for HCMV. No positive association was found between HCMV and periodontitis or gingivitis (p = 0.479). The elevated occurrence of EBV-1 DNA in periodontal pockets of patients with aggressive periodontitis supports a possible periodontopathic role of this virus.
O objetivo do presente estudo foi comparar a presença do vírus Epstein-Barr tipo 1 (EBV-1) e do Citomegalovírus Humano (HCMV) em amostras de fluido crevicular de bolsas periodontais rasas e profundas de pacientes brasileiros com periodontite agressiva. Trinta pacientes sistemicamente saudáveis com periodontite agressiva participaram deste estudo. Cones de papel foram inseridos em 2 sítios de gengivite (< 3 mm) e em 2 sítios de periodontite (> 5 mm) de cada paciente. Reações de PCR foram usadas para identificar cópias de DNA genômico de HCMV e EBV-1. Em 23 pacientes (77%), os testes foram positivos para EBV-1, enquanto apenas 2 pacientes (6%) foram positivos para HCMV. O teste de McNemar apontou associação positiva entre EBV-1 e lesões periodontais (p = 0,043). Trinta e quatro (57%) dos 60 sítios de periodontites foram positivos para o EBV-1, enquanto 18 (30%) dos sítios de gengivites foram positivos (p = 0,01). Apenas 2 sítios (6,7%) foram positivos para o HCMV. Não foi encontrada associação positiva entre HCMV e periodontite ou gengivite (p = 0,479). A alta ocorrência de DNA de EBV-1 em bolsas periodontais de pacientes com periodontite agressiva corrobora a possível função periodontopática deste vírus.