ABSTRACT PURPOSE: To evaluate the effect of the Chenopodium ambrosioides L (mastruz) extract for preventing bone loss and bone metabolism in ovariectomized rats. METHODS: Twelve rats were subjected to bilateral ovariectomy for inducing osteoporosis. After surgery, they were divided into two groups: Ovariectomy-control group (G1, n=6), receiving 0.5 ml distilled water by gavage for 30 days, and Ovariectomy plus mastruz group (G2, n=6), receiving 0.5 ml of the hydroalcoholic extract of mastruz at 10% concentration (50mg) daily, for the same period. Then, the blood of the animals was collected for further biochemical analysis (liver function) and tibia and liver were removed for histological and histomorphometric analyses. RESULTS: The cortical bone was significantly larger in the G2 than G1, whereas G1 presented the highest amount of adipocytes in the bone marrow (p<0.05). The blood levels of aspartate aminotransferase, triglycerides and cholesterol were significantly higher, whereas globulin and lactate dehydrogenase were smaller in G2 than G1. CONCLUSION: The hydroalcoholic extract of mastruz has effects on bone metabolism by changing blood proteins and enzymes and preventing both bone loss and the substitution of bone marrow cells by

This study aimed to evaluate the survival of atraumatic restorative treatment high-viscosity glass ionomer sealants (ART-hvGIS) and its relationship with carious lesions incidence in underserved communities of Ecuador. A total of 483 first permanent molars with ART-hvGIS were included after treatment, in which fifteen students of the First Preventive Dentistry Post Graduate Program of Universidad Central del Ecuador assisted 176 schoolchildren, from 5 to 12 year-old. All the students had previously participated in a training course in ART approach. After one and two years follow-up, schoolchildren were reevaluated in relation to sealants retention and new carious lesions development. After first year of evaluation ART-hvGIS retention rate was about 30% and after second year 20%. Incidence of carious lesions was 4.0 and 3.4% after first and second periods, respectively. Although there was an extensive ART-hvGIS loss, carious lesions incidence was low in both the periods of evaluation. ART-hvGIS might be an important key to prevent tooth decay in underserved communities.

Hyposalivation and dental root exposure in the elderly are problems that require special oral care. In this context, the characteristics of certain toothpastes are of particular importance. Thus, the aim of this study was to evaluate the cytotoxicity and dentin wear caused by seven different toothpastes. For dentin wear analysis, 40 root dentin specimens were submitted to 20,000 brushing cycles with the different toothpastes and distilled water (control group-CG), using a brushing machine. Dentin surface loss (SL) was measured by contact profilometer. The cytotoxicity of each toothpaste was tested using cultured fibroblasts submitted to a cell-culture-conditioned medium. Fresh medium served as the control. Cell viability was assessed by MTT assay after 24 h of contact with the conditioned media. The data were analyzed statistically by ANOVA, followed by Tukey’s test (p < 0.05). The SL of the CG was minimal and significantly lower than that of the Oral B Pro Health (OBPH) group (p < 0.05). All other groups presented SL in between that of the CG and the Oral B Pro Health OBPH group, except for the Sensodyne (SEN) group, which presented SL similar to that of CG (p = 0.05). The SEN group presented a percentage of viable cells similar to that of CG: between 60-89%. All the other toothpastes showed high cytotoxicity, with cell viability less than 50% of the CG. Considering study limitations, we concluded that only one of the seven tested toothpastes exhibited the most desirable toothpaste characteristics for the worldwide growing elderly population (e.g. low cytotoxicity and low-abrasive potential).

The aim of this study was to characterize calcium phosphate ceramics with different Ca/P ratios and evaluate cell response of these materials for use as a bone substitute. Bioceramics consisting of mixtures of hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) powders in different proportions were pressed and sintered. The physical and chemical properties of these bioceramics were then characterized. Characterization of the biological properties of these materials was based on analysis of cell response using cultured fibroblasts. The number of cells attached to the samples was counted from SEM images of samples exposed to cell culture solution for different periods. These data were compared by analysis of variance (ANOVA) complemented by the Tukey's test. The TCP sample had higher surface roughness and lower density. The adherence and growth of FMM1 cells on samples from all groups was studied. Even though the different calcium based ceramics exhibited properties which made them suitable as bone substitutes, those with higher levels of β-TCP revealed improved cell growth on their surfaces. These observations indicated two-phase calcium phosphate based materials with a β-TCP surface layer to be a promising bone substitute.

Os bisfosfonatos (BFs) têm sido indicados para o tratamento de doenças do metabolismo ósseo. Atualmente, seu emprego terapêutico aumentou e, com ele, os efeitos adversos, dos quais um dos mais importantes é a indução da osteonecrose dos maxilares, uma complicação de difíceis tratamento e solução. Até o presente, não se sabe ao certo qual é o mecanismo de desenvolvimento da osteonecrose dos maxilares induzida por bisfosfonatos (ONMB), nem qual deve ser o tratamento estabelecido perante essa manifestação. Apesar de a literatura apresentar formas variadas de tratamento, não existe um protocolo definido. Apresentamos uma revisão sobre a ONMB, enfocando sua etiopatogenia e as formas reportadas de tratamento.

Bisphosphonates (BPs) have been used for the management of bone metabolic diseases. Currently their therapeutic use has increased, as also have their adverse effects, one of the most important being the bisphosphonate-related osteonecrosis of the jaw (BRONJ), a complication of difficult treatment and solution. Until now, the physiopathology of BRONJ remains unclear, and its treatment is uncertain. Although the literature provides several treatment options, there is no defined protocol. We present a review about BRONJ, focusing on its pathogenesis and its reported forms of treatment.

Little is known about the histogenesis of the odontogenic myxoma (OM). Dental pulp stem cells could be candidate precursors of OM because both OM and the dental pulp share the same embryological origin: the dental papilla. For the purpose of comparing OM and stem cells, this study analyzed the expression of two proteins related to OM invasiveness (MMP-2 and hyaluronic acid) in human immature dental pulp stem cells (hIDPSCs). Three lineages of hIDPSCs from deciduous and permanent teeth were used in this study. Immunofluorescence revealed positive reactions for MMP-2 and hyaluronic acid (HA) in all hIDPSCs. MMP-2 appeared as dots throughout the cytoplasm, whereas HA appeared either as diffuse and irregular dots or as short fibrils throughout the cytoplasm and outside the cell bodies. The gene expression profile of each cell lineage was evaluated using RT-PCR analysis, and HA was expressed more intensively than MMP-2. HA expression was similar among the three hIDPSCs lineages, whereas MMP-2 expression was higher in DL-1 than in the other cell lines. The expression of proteins related to OM invasiveness in hIDPSCs could indicate that OM originates from dental pulp stem cells.

Aiming to compare the effect of different light sources for dental bleaching on vascular permeability of dental pulps, forty-eight incisors were used. The bleaching agent (35 % hydrogen peroxide) was activated by halogen light; LED (Light Emitting Diode) or LED, followed by laser phototherapy (LPT) (λ = 780 nm; 3 J/cm²). After the bleaching procedures, the animals received an intra-arterial dye injection and one hour later were sacrificed. The teeth were diaphanized and photographed. The amount of blue stain content of each dental pulp was quantified using a computer imaging program. The data was statistically compared (p < 0.05). The results showed a significant higher (p < 0.01) dye content in the groups bleached with halogen light, compared with the control, LED and LED plus LPT groups. Thus, tooth bleaching activated by LED or LED plus LPT induces lesser resulted in increased vascular permeability than halogen light.

The purpose of this study was to test the hypothesis that both human and bovine sclerotic dentin have similar hardness properties, in addition to similar micromorphological characteristics. Sixteen teeth (8 human and 8 bovine) exhibiting exposed dentin in the incisal edge and showing characteristics typical of sclerosis were used. Vickers surface microhardness testing was conducted. Three areas of the dentin surface of each specimen were selected. All teeth were processed for scanning electron microscopy in order to estimate the amount (in percentage) of solid dentin on the sclerotic dentin surface. The data were compared by Student's t test (α = 0.05). The micromorphological and microhardness data were compared by Pearson's linear correlation test (α = 0.05). The mean percentages of solid dentin of human and bovine sclerotic dentin were similar (human 90.71 ± 0.83 and bovine 89.08 ± 0.81, p = 0.18). The mean microhardness value (VHN) of human sclerotic dentin was significantly higher than that of bovine sclerotic dentin (human 45.26 ± 2.92 and bovine 29.93 ± 3.83, p = 0.006). No correlation was found between the microhardness values and the amount of solid dentin in the sclerotic dentin, irrespective of the species considered (human R² = 0.0240, p = 0.714; bovine R² = 0.0017, p = 0.923; and combined R² = 0.038, p = 0.46). We concluded that although both bovine and human sclerotic dentin present a similar amount of solid tissue, human sclerotic dentin presents higher microhardness than bovine sclerotic dentin.

Pulp repair is a complex process whose mechanisms are not yet fully understood. The first immune cells to reach the damaged pulp are neutrophils that play an important role in releasing cytokines and in phagocytosis. The objective of this study was to analyze the effect of different pulp-capping materials on the secretion of interleukin-1 beta (IL-1β) and interleukin-8 (IL-8) by migrating human neutrophils. Neutrophils were obtained from the blood of three healthy donors. The experimental groups were calcium hydroxide [Ca(OH)2], an adhesive system (Single Bond), and mineral trioxide aggregate (MTA). Untreated cells were used as control. Transwell chambers were used in performing the assays to mimic an in vivo situation of neutrophil chemotaxis. The pulp-capping materials were placed in the lower chamber and the human neutrophils, in the upper chamber. The cells were counted and the culture medium was assayed using ELISA kits for detecting and quantifying IL-1β and IL8. The data were compared by ANOVA followed by Tukey's test (p < 0.05). The secretion of IL-8 was significantly higher in all groups in comparison to the control group (p < 0.05). The adhesive system group showed higher IL-8 than the MTA group (p < 0.05). The secretion of IL-1β was significantly greater only in the MTA group (p < 0.001). It was concluded that only MTA is able to improve the secretion of IL-1β, and all materials tested increased IL-8 secretion. These results combined with all the other biological advantages of MTA indicate that it could be considered the material of choice for dental pulp capping.

This in vitro study aimed to analyze the effect of different parameters of phototherapy with low intensity laser on the viability of human dental pulp fibroblasts under the effect of substances released by bleaching gel. Cells were seeded into 96 wells plates (1 x 10³ cells/well) and placed in contact with culture medium conditioned by a 35 % hydrogen peroxide bleaching gel for 40 minutes, simulating the clinical condition of the in-office bleaching treatment. Cells cultured in ideal growth conditions served as positive control group (PC), and the cells grown in conditioned medium and non-irradiated served as negative control group (NC). Cells grown in conditioned medium were submitted to a single irradiation with a diode laser (40 mW, 0.04 cm²) emitting at visible red (660 nm; RL) or near infrared (780 nm; NIR) using punctual technique, in contact mode and energy densities of 4, 6 or 10 J/cm². The cell viability was analyzed through the MTT reduction assay immediately and 24 hours after the irradiation. The data was compared by ANOVA followed by the Tukey's test (p < 0.05). The cell viability increased significantly in 24 hours within each group. The PC presented cell viability significantly higher than NC in both experimental times. Only the NIR/10 J/cm² group presented cell viability similar to that of PC in 24 hours. The phototherapy with low intensity laser in defined parameters is able to compensate the cytotoxic effects of substances released by 35 % hydrogen peroxide bleaching gel.

The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9% saline solution and 1% sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.

Aggregatibacter actinomycetemcomitans é um importante agente etiológico da periodontite e produz infecções extra-bucais. Neste estudo, foram detectados os biótipos, o gene ltxA associado à produção de leucotoxina e o promotor ltx em A. actinomycetemcomitans de pacientes com e sem periodontite. A atividade leucotóxica sobre células HL-60 também foi avaliada. A atividade leucotóxica foi determinada através do método de exclusão do azul de tripam. A deleção de 530 bp no promotor ltx foi avaliada usando-se o par de iniciadores PRO. A. actinomycetemcomitans foi detectado por cultura e por PCR. Por cultura, A. actinomycetemcomitans foi detectado em nove pacientes com periodontite (18%) e em um indivíduo sadio (2%). Por PCR esse microrganismo foi detectado em 44% dos pacientes com periodontite e em 16% dos saudáveis. Verificou-se diferença estatística entre a detecção do promotor do operon ltx, por PCR, diretamente do biofilme subgengival e do DNA bacteriano. Somente uma amostra clínica apresentou A. actinomycetemcomitans altamente leukotóxico. O biótipo II foi o mais prevalente e não foi observada correlação biótipo-atividade leucotóxica. A expressão da leucotoxina por A. actinomycetemcomitans na doença periodontal e outras doenças infecciosas necessita ser avaliado.

Aggregatibacter actinomycetemcomitans is an important etiologic agent of the periodontitis and is associated with extra-oral infections. In this study, the detection of the ltxA gene as well as the ltx promoter region from leukotoxic A. actinomycetemcomitans isolated from 50 Brazilian patients with periodontitis and 50 healthy subjects was performed. The leukotoxic activity on HL-60 cells was also evaluated. Leukotoxic activity was determined using a trypan blue exclusion method. The 530 bp deletion in the promoter region was evaluated by PCR using a PRO primer pair. A. actinomycetemcomitans was detected by culture and directly from crude subgingival biofilm by PCR using specific primers. By culture, A. actinomycetemcomitans was detected in nine (18%) of the periodontal patients and one (2%) healthy subject. However, by PCR, this organism was detected in 44% of the periodontal patients and in 16% of the healthy subjects. It was verified a great discrepancy between PCR detection of the ltx operon promoter directly from crude subgingival biofilm and from bacterial DNA. Only one periodontal sample harbored highly leukotoxic A. actinomycetemcomitans. Moreover, biotype II was the most prevalent and no correlation between biotypes and leukotoxic activity was observed. The diversity of leukotoxin expression by A. actinomycetemcomitans suggests a role of this toxin in the pathogenesis of periodontal disease and other infectious diseases.

The objective of the present study was to characterize bone cells grown in two culture media, and to determine the effective concentration of OP-1 on the growth of osteo-1 cells. Subcultured rat bone cells (osteo-1) were grown in alpha-modified Eagle's minimal essential medium (alpha-MEM) and Dulbecco's modified Eagle's medium (DMEM) and total protein content, alkaline phosphatase activity and the formation of mineralized nodules were evaluated after 7, 14 and 21 days. Cells were exposed to different concentrations of rhOP-1 for 1, 3, 5 and 7 days and compared with an untreated control. Osteo-1 cells presented a significant increase in alkaline phosphatase activity and calcium deposits were observed at 21 days. Cells treated with 10 and 20 ng/mL rhOP-1 for 24 h showed a significant increase in cell viability when compared to control. Osteo-1 cells cultured on DMEM demonstrated an osteoblastic phenotype as indicated by high alkaline phosphatase activity and the presence of calcified nodules. The results suggest that low concentrations of OP-1 may promote an osteogenic effect on osteo-1 cells.

A matriz extracelular (MEC) tem um papel importante na regulação do crescimento e na diferenciação e organização dos tecidos. Com base nestes aspectos o objetivo do deste estudo foi analisar o colágeno, maior componente orgânico da MEC da polpa dentária, na papila de germes dentários humanos, em diferentes fases do desenvolvimento. Foram obtidos fragmentos de maxilas e mandíbulas de 9 fetos humanos com 10 a 22 semanas de vida intra-uterina, dos quais foram analisados 16 germes dentários (1 em estágio de capuz, 8 em estágio de campânula precoce e 7 em estágio de campânula tardia). Secções histológicas seriadas foram coradas com hematoxilina e eosina, tricrômico de Masson e técnica de coloração do picrosirius. Ambos os tipos de colágeno na papila dentária foram somente detectados pela técnica de coloração do picrosirius usando microscopia de luz polarizada. Colágeno tipo III foi detectado em todas as amostras. Colágeno tipo I estava presente em áreas focais da papila dental em algumas amostras. Concluiu-se que o colágeno tipo III mostrou-se um componente regular da papila de germes dentários humanos, enquanto o colágeno tipo I esteve presente em quantidade significativamente menor.

The extracellular matrix (ECM) performs a very important role in growth regulation and tissue differentiation and organization. In view of this, the purpose of this study was to analyze the collagen, the major organic component of dental pulp ECM, in papillae of human tooth germs in different developmental phases. The maxillas and mandibles of 9 human fetuses ranging from 10 to 22 weeks of intrauterine life were removed and 16 tooth germs (1 in the cap stage, 8 in the early bell stage and 7 in the late bell stage) were obtained. The pieces were processed for histological analysis and stained with hematoxylin-eosin, Masson's Trichrome and picrosirius staining technique. Both types of collagen in the dental papilla were only detected by the picrosirius staining technique under polarized light microscopy. Type III collagen was detected in all specimens. Type I collagen was present in focal areas of the dental papilla only in some specimens. In conclusion, the findings of this study showed that type III collagen is a regular component of the papillae of human tooth germs whereas type I collagen is present in a significantly lesser amount.

Os cianoacrilatos tem encontrado aplicabilidade tanto na Medicina como na Odontologia há muitos anos. Têm sido usados como curativo após exodontias, bem como para obturação retrógrada em cirurgia parendodôntica. O objetivo deste estudo foi o de avaliar o efeito citotóxico do Histoacryl e outros dois homólogos etil cianoacrilatos: SuperBonder e Ultrabond, em cultura de fibroblastos, empregando ensaios de viabilidade pela exclusão de células coradas pelo azul de Trypan. Os cianoacrilatos foram aplicados em lamínulas de vidro circulares, que foram colocadas sobre cultura de fibroblastos NIH - 3T3. Após 0, 6, 12 e 24 horas (resposta celular imediata - curto prazo) e 1, 3, 5 e 7 dias (sobrevivência celular - longo prazo), foram efetuadas contagens celulares em microscópio de fase. Os dados obtidos foram analisados valendo-se do teste estatístico de Kruskal-Wallis. No experimento de curto prazo, somente as culturas do grupo Ultrabond (GIV) apresentaram porcentagens de viabilidade celular significantemente menores que a dos outros grupos (GI: controle; GII: Super Bonder; GIII: Histoacryl). Embora as culturas do grupo Super Bonder (GII) apresentassem porcentagens de viabilidade celular menores que as dos outros grupos (GI, GIII, GIV) no experimento de longo prazo, esse grupo foi o único que mostrou crescimento celular progressivo e contínuo. Nossos resultados mostraram biocompatibilidade in vitro tanto do Histoacryl como dos outros dois homólogos etil cianoacrilatos. Esses cianoacrilatos podem ser importantes para finalidades biológicas.

Cyanoacrylate has been used in medicine and dentistry for many years. It has been used as a postextraction dressing and retrograde filling material in endodontic surgery. The aim of this study was to evaluate the cytotoxic effects of Histoacryl and other two homologue ethyl cyanoacrylates, Super Bonder and Ultrabond, on cultured fibroblasts, using the Trypan blue dye exclusion assay. The cyanoacrylates were applied to round glass coverslips, which were placed in contact with NIH 3T3 cells. After 0, 6, 12 and 24 h (short-term assay; viability) and 1, 3, 5 and 7 days (long-term assay; survival), the cells were examined under phase light microscopy and counted. The data were compared by the Kruskal-Wallis test. In the short-term experiments, only the cultures of the Ultrabond group (GIV) presented significant smaller percentages of cell viability than the cultures of the other groups (GI: control; GII: Super Bonder; GIII: Histoacryl). Although the cultures of the Super Bonder group (GII) presented smaller percentages of cell viability than cultures of the other groups (GI, GIII, GIV) at the long-term assay, this group was the only experimental group presenting a continuous and progressive cell growth. Our results have shown an in vitro biocompatibility of Histoacryl and ethyl cyanoacrylate homologues. These cyanoacrylates could therefore be of importance for endodontic purposes.