Four-Octyl itaconate ameliorates periodontal destruction via Nrf2-dependent antioxidant system / 国际口腔科学杂志·英文版

Periodontitis is a widespread oral disease characterized by continuous inflammation of the periodontal tissue and an irreversible alveolar bone loss, which eventually leads to tooth loss. Four-octyl itaconate (4-OI) is a cell-permeable itaconate derivative and has been recognized as a promising therapeutic target for the treatment of inflammatory diseases. Here, we explored, for the first time, the protective effect of 4-OI on inhibiting periodontal destruction, ameliorating local inflammation, and the underlying mechanism in periodontitis. Here we showed that 4-OI treatment ameliorates inflammation induced by lipopolysaccharide in the periodontal microenvironment. 4-OI can also significantly alleviate inflammation and alveolar bone loss via Nrf2 activation as observed on samples from experimental periodontitis in the C57BL/6 mice. This was further confirmed as silencing Nrf2 blocked the antioxidant effect of 4-OI by downregulating the expression of downstream antioxidant enzymes. Additionally, molecular docking simulation indicated the possible mechanism under Nrf2 activation. Also, in Nrf2-/- mice, 4-OI treatment did not protect against alveolar bone dysfunction due to induced periodontitis, which underlined the importance of the Nrf2 in 4-OI mediated periodontitis treatment. Our results indicated that 4-OI attenuates inflammation and oxidative stress via disassociation of KEAP1-Nrf2 and activation of Nrf2 signaling cascade. Taken together, local administration of 4-OI offers clinical potential to inhibit periodontal destruction, ameliorate local inflammation for more predictable periodontitis.

Signs of alveolar bone damage in early stages of periodontitis and its prevention by stimulation of cannabinoid receptor 2. Model in rats / Signos de daño óseo alveolar en estadios tempranos de periodontitis y su prevención por estimulación del receptor cannabinoide 2. Modelo en ratas microcisalhamento do cimento resinoso

ABSTRACT The aims of the present study were, first, to identify signs of alveolar bone damage in early stages of experimental periodontitis (EP) and, second, to assess its possible prevention by treatment with cannabinoid receptor 2 agonist HU 308. Experimental periodontitis was induced by injections of lipopolysaccharide (LPS) (1mg/ml) in gums surrounding maxillary and mandibular first molar, 3 days per week, and untreated controls were kept for comparison. Then, a 3-week study was conducted including eighteen new rats (six rats per group): 1) controls; 2) experimental periodontitis rats; and 3) experimental periodontitis rats treated daily with HU 308 (500 ng/ml). After euthanasia, alveolar bone loss was assessed by morphometric and histomorphometric techniques, and the content of prostaglandin E2 (PGE2) in gingival tissue was evaluated by radioimmunoassay. The first signs of alveolar bone loss were apparent at 3 weeks of experimental periodontitis (ρ<0.05) in the mandibular first molar, but there was no detectable change at 1 week, leading us to establish 3 weeks as an early stage of experimental periodontitis. Rats subjected to 3-week experimental periodontitis showed less interradicular bone volume, less whole bone perimeter and fewer bone formation areas, and higher periodontal space height, bone resorption areas, number of osteoclasts and gingival content of prostaglandin E2 than controls, while HU 308 prevented, at least partially, the deleterious effects (ρ<0.001). We can conclude that a 3-week term of lipopolysaccharide-induced periodontitis in rats provides a valid model of the early stage of the disease, as emerging damage is observed in bone tissue. Furthermore, harmful effects at 3 weeks could be prevented by local stimulation of cannabinoid receptor 2, before greater damage is produced.

RESUMEN El objetivo del presente trabajo fue, en primer lugar, identificar signos de daño óseo alveolar en estadios tempranos de periodontitis experimental y, en segundo lugar, evaluar su posible prevención mediante el tratamiento con el agonista del receptor cannabinoide 2, HU 308. La periodontitis experimental fue inducida por inyecciones de lipopolisacárido (1mg/ml) en la encía circundante al primer molar maxilar y mandibular, 3 días por semana, en tanto que controles no tratados fueron mantenidos para la comparación. Posteriormente, un estudio de 3 semanas con dieciocho nuevas ratas (seis por grupo) fue desarrollado: 1) controles; 2) ratas con periodontitis experimental, y 3) ratas con periodontitis experimental tratadas diariamente con HU 308 (500ng/ml). Luego de la euthanasia, la pérdida ósea alveolar fue evaluada por técnicas morfométricas e histomorfométricas, y el contenido de prostaglandina E2 en el tejido gingival fue determinado por radioinmunoensayo. Los primeros signos de pérdida ósea alveolar fueron evidentes a las 3 semanas de inducción de periodontitis experimental (ρ<0.05) en el primer molar mandibular, mientras que no hubo cambios detectables luego de 1 semana de inducción, hecho que nos condujo a establecer a las 3 semanas como un estadio temprano de periodontitis experimental, Las ratas sometidas a perdiodontitis experimental de 3 semanas mostraron menor volumen óseo interradicular, menor perímetro óseo y menos áreas de formación ósea, y mayor altura del espacio periodontal, más áreas de reabsorción ósea, mayor número de osteoclastos y mayor contenido gingival de prostaglandina E2, en comparación a los controles, mientras que el tratamiento con HU 308 previno, al menos parcialmente, los efectos deletéreos (ρ<0.001). Podemos concluir que el término de 3 semanas de periodontitis inducida por lipopolisacárido es un modelo válido de estadio inicial de la enfermedad experimental, dado que se evidencia daño emergente en el tejido óseo. Asimismo, los efectos deletéreos de 3 semanas podrían ser prevenidos por la estimulación local del receptor cannabinoide 2, antes que un daño mayor sea producido.

Effects of low molecular weight heparin on alveolar bone loss in wistar rats

Abstract This study aimed to assess the effects of low molecular weight heparin (LMWH) on alveolar bone loss (ABL), blood count, and counting of megakaryocytes and adipocytes in male Wistar rats. Forty male 60-day Wistar rats were randomly divided into four groups: Control (C), Periodontal Disease (PD), Heparin (Hp) and Heparin + Periodontal Disease (Hp+PD). LMWH was applied for 60 days at doses of 1 ml/kg/day. Blood samples were collected at baseline, 30 and 60. On day-49, PD and Hp+PD groups were subjected to ligature-induced periodontitis around second upper right molar. The left side was assessed as spontaneous alveolar bone loss. Mean ABL in the side with ligature showed significantly different between C (0.35±0.07 mm) and Hp+DP (0.49±0.09 mm) groups (p<0.001), between PD (0.55±0.11 mm) and Hp (0.32±0.06 mm) groups (p<0.001) and between Hp and Hp+DP groups (p<0.001). No significant differences were found among groups for ABL in the side without ligature. Animal weight, food intake, and water consumption showed no statistically significant difference among groups. Megakaryocytes and adipocytes were counted using optical microscopy and no statistically significant differences were found. Within-groups, there were an increase and a decrease, respectively, in the counting of lymphocytes (p=0.005 for C and p=0.009 for Hp+PD groups only) and leukocytes (p=0.003 for C, p=0.001 for PD, p=0.002 for Hp, and p<0.001 for Hp+PD groups). There was no decrease in the number of platelets in the three collection periods. LMWH was not able to affect ABL, but it may change the blood counting, especially increasing lymphocytes.

Resumo O presente estudo objetivou verificar o efeito da heparina de baixo peso molecular (HBPM) sob a perda óssea alveolar (POA), contagem de células sanguíneas, megacariócitos e adipócitos em ratos Wistar machos. Quarenta ratos Wistar de 60 dias foram randomicamente divididos em quatro grupo: Controle (C), Doença Periodontal (DP), Heparina (Hp) e Heparina + Doença Periodontal (Hp+DP). HBPM foi aplicada durante 60 dias em doses de 1 mL/kg/dia. Coletas sanguíneas foram realizadas nos dias 0, 30 e 60. No dia 49, os grupos DP e Hp+DP receberam indução de doença periodontal por ligadura ao redor do segundo molar superior direito. No lado esquerdo, verificou-se perda óssea alveolar espontânea. A média de POA no lado com ligadura mostrou-se estatisticamente diferente entre os grupos C (0,35±0,07 mm) e Hp+PD (0,49±0,09 mm) (p<0,001), entre os grupos DP (0,55±0,11 mm) e Hp (0,32±0,06 mm) (p<0,001) e entre os grupos Hp e Hp+DP (p<0,001). Nenhuma diferente significativa foi observada entre os grupos no lado sem ligadura. Peso dos animais, consumo de ração e ingestão de água não mostraram diferenças significativas entre os grupos. Megacariócitos e adipócitos foram contados por microscopia óptica e nenhuma diferença significativa foi encontrada. Dentro dos grupos, houve um aumento e uma diminuição, respectivamente, na contagem de linfócitos (p=0,005 no grupo C e p=0,009 no grupo Hp+DP somente) e leucócitos (p=0,003 no grupo C, p=0.001 no grupo DP e p=0,002 no grupo Hp e Hp+DP). Não houve diminuição no número de plaquetas nos três períodos de coleta. HBPM não foi capaz de modificar a POA, porém modificou a contagem de células sanguíneas, especialmente aumentando o número de linfócitos.

Preservation of dental sockets filled with composite bovine bone. A single-blind randomized clinical trial

Abstract The purpose of this study was to evaluate the preservation of alveolar dimensions in human fresh extraction sockets filled with a composite bovine bone graft by means of design of single-blind randomized clinical trial. Forty participants had monoradicular teeth extracted (one teeth in each participant), and after were randomly divided into 2 groups: individuals whose fresh sockets were filled with the composite heterologous bone graft (Biomaterial Group), or with blood clot (Control Group). After extraction, the fresh sockets were measured at their greatest mesiodistal (MD) and bucco-lingual/palatal (BL/P) distance. Primary closure of the soft tissue was performed with a fibro-mucosal plug. After 120 post-operative days, the re-entry procedure was performed and the largest MD and BL/P measurements were again obtained to calculate the remodeling of the alveolar bone measured in percentage. In the biomaterial group, a percentage reduction of 1.62% and 3.29% in the MD and BL/P dimensions was observed 120 days after the extractions, whereas a reduction of 4.97% and 7.18% in the MD and BL/P dimensions occurred in the control group. There was a statistically significant difference (p<0.05) between the two groups for the bucco-palatal and mesiodistal measurements in the maxilla. In view of the results obtained, it can be concluded that composite bovine bone graft limited but did not impede alveolar bone remodeling.

Resumo O objetivo deste estudo foi avaliar em humanos a manutenção do volume em alvéolos frescos preenchidos por osso integral de origem bovina por meio de um estudo clínico randomizado com monocegamento. Quarenta dentes uni radiculares foram extraídos em 40 pacientes (um dente em cada participante), e apos estes pacientes foram divididos aleatoriamente em 2 grupos: indivíduos que tiveram o alvéolo fresco preenchido por osso integral de origem bovina (Grupo Biomaterial) ou por coagulo sanguíneo (Grupo Controle). Apos a exodontia os alvéolos foram medidos em suas maiores distancias mesio-distal (MD) e vestíbulo lingual/palatina (VL/P) por meio de compasso de ponta seca. O fechamento primário dos alvéolos foi realizado com um tampão fibromucoso. Apos 120 dias pós-operatórios durante o procedimento de reabertura foram obtidas novamente as maiores medidas MD e VL/P para calcular em porcentagem o nível de remodelação do osso alveolar. No grupo biomaterial observou-se uma redução em porcentagem de 1,62% e 3,29% nas medidas MD e VL/P 120 dias apos as extrações, enquanto no grupo controle houve uma redução de 4,97% e 7,18% nas medidas MD e VL/P no mesmo período. Houve diferença estatisticamente significante (p<0,05) entre os dois grupos para as medidas vestíbulo/palatina e mesiodistal na maxila. Diante dos resultados obtidos conclui-se que o osso integral de origem bovina limitou, mas não impediu a remodelação óssea alveolar.

Expressão de citocinas relacionadas à resposta Th17 no fluido peri-implantar de mucosites em pacientes com e sem perda óssea alveolar / Expression of cytokines related to Th17 response in peri-implant fluid of mucositis in patients having or not alveolar bone loss

O objetivo do presente estudo foi analisar os níveis de IL-1ß, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L e TNF-α no fluido peri-implantar de mucosite em pacientes sem perda óssea alveolar e compará-los com os níveis na mucosite de pacientes com peri-implantite e de pacientes com periodontite. Trinta e três pacientes foram divididos em três grupos: (1) Mucosite peri-implantar (idade média 59,8±7,5, seis mulheres e quatro homens), (2) Peri-implantite (idade média 59,9±3,8, nove mulheres e cinco homens) e (3) Periodontite (idade média 66,7±8,8, cinco mulheres e quatro homens). Os parâmetros clínicos avaliados foram: profundidade de bolsa (PB), nível de inserção clínica (NIC), índice de placa e sangramento à sondagem. Em cada paciente foi realizada a coleta do fluido peri-implantar com pontas de papel absorvente pré-fabricadas. No grupo 1, foram coletados de sítios com mucosite (perda óssea ao redor dos implantes não atingindo a primeira rosca); no grupo 2, foram coletados sítios de mucosite e de peri-implantite (perda óssea de duas ou mais roscas do implante); no grupo 3, foram coletados de sítios com mucosite e com periodontite (PB ≥ 5mm e NIC ≥ 3mm). As amostras foram submetidas à análise imunológica e os níveis de citocinas foram mensurados através do ensaio multiplex com microesferas. Os resultados das características clínicas de boca toda demonstraram que a PB média do grupo 1 (2,0mm±0,1) foi significativamente menor quando comparado com o grupo 2 (2,6mm±0,4) e ao grupo 3 (2,5mm±0,3), com p<0,001 e p=0,01 respectivamente. Quanto ao NIC e a presença de placa, não houve diferença significativa entre os grupos. Avaliando as características clínicas peri-implantares dos sítios com mucosite peri-implantar dos três grupos, estes foram semelhantes, exceto pelo fato do percentual de sangramento no grupo 1 ser significativamente menor do que no grupo 3 (p=0,05). Ao comparar os níveis de citocinas nos sítios com mucosite dos três grupos, não houve diferença significativa. No grupo 2, ao comparar os níveis de citocinas nos sítios inflamados com mucosite e peri-implantite, a única citocina que apresentou diferença significativa foi a IL-21, sendo maior nos sítios com mucosite (p=0,04). No grupo 3, não foram observadas diferenças significativas entre os sítios com mucosite e sítios com periodontite. Assim, com base nos resultados obtidos, pôde-se concluir que os níveis de citocinas relacionadas à resposta Th17 no fluido peri-implantar de mucosite em pacientes sem perda óssea alveolar não apresentaram diferenças significantes daqueles na mucosite de pacientes com peri-implantite e de pacientes com periodontite.

This study aimed to analyse the levels of IL-1ß, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L, and TNF-α in peri-implant fluid from mucositis in patients without alveolar bone loss and to compare with the levels of mucositis from in peri-implantitis patients and with mucositis from periodontitis patients. Thirty three patients were divided in three groups: (1) Peri-implant Mucositis (average age 59.8 ± 7.5, six women and four men), (2) Peri-implantitis (average age 59.9 ± 3.8, nine women and five men) and (3) Periodontitis (average age 66.7 ± 8.8, five women and four men). The following clinical parameters were evaluated: probing depth (PD), clinical attachment level (CAL), visible plaque index and bleeding on probing. Peri-implant fluid was collected in each patient using pre-fabricated absorbent paper. In group 1, fluid was collected from mucositis sites (bone loss around the implant did not reach the first thread); in group 2, it was collected from mucositis sites and from peri-implantitis sites (bone loss involving two or more threads of the implant); in group 3, is was collected from mucositis sites and also from periodontitis sites (PD ≥ 5mm and CAL ≥ 3mm). Cytokines level were measured by a bead-based multiplex assay. Regarding full-mouth periodontal parameters, the mean PD of group 1 (2.0 mm ± 0.1) was significantly decreases when compared to group 2 (2.6 mm ± 0.4) and to group 3 (2.5 mm ± 0.3), with p<0.001 and p=0.01 respectively. CAL and visible plaque index did present no significant difference among the groups. Regarding the peri-implant clinical characteristics, it was found that peri-implant mucositis were similar, except for the significantly decreased bleeding on probing in group 1 in comparison with that in group 3 (p=0.05). When comparing the levels of cytokines in sites with peri-implant mucositis, there was no significant difference among them. In group 2, the levels of cytokines IL-21 was higher in sites with peri-implant mucositis when compared with peri-impantitis (p=0.04). In group 3, there were no significant differences between sites with mucositis sites and sites with periodontitis. Thus, based on these results, we can conclude that the levels of cytokines related to Th17 response in the peri-implant fluid from mucositis in patients without alveolar bone loss showed no significant differences in comparison to those from mucositis in patients with peri-implantitis and patients with periodontitis.

Periointegración / Periointegration

Se busca entender cuáles son las respuestas biológicas que se dan en diferentes etapas de la implantología, centrando la atención en la influencia de la tecnología en la formación del ancho biológico. Se analiza cómo fue evolucionando la ciencia en la búsqueda de mejores respuestas y cuáles serán los factores decisivos para que la tecnología influencie a la biología y poder aproximarse cada vez más a lo natural.

The aim of this paper is to understand the biological responses at the different stages of implantology, with a focus on the influence of technology in the formation of the biological width. It presents a study of the evolution of science towards better responses and the determining factors for technology to influence biology, which allow us to get closer to what is natural.

Utilización de sulfato de calcio hemihidratado como material de relleno y barrera en un alveolo post-exodoncia: Una observación clínica, tomográfica e histológica comparativa a 4 meses antes de la colocación de implantes / Use of calcium sulfate hemihydrate as a filler and barrier in a post-extraction alveolus. A clinical, tomographic and histological comparative observation to 4 months before implant placement

Evaluar y comparar de forma clínica, tomográfica e histológica el proceso de reparación ósea y la conservación del reborde alveolar en dos alveolos post-extracción de paredes intactas, con y sin la utilización de un material sustituto óseo regenerativo a base de sulfato de calcio hemihidratado como relleno y barrera, antes de la colocación de implantes a cuatro meses.

To evaluate and compare clinically, tomographic and histological the bone repair process and the preservation of the alveolar walls of two sockets intact, with and without the use of a bone substitute material based regenerative calcium sulfate hemihydrate as a filler and barrier before implant placement to four months.

Crestal bone preservation: A review of different approaches for successful implant therapy.

The level of bone crest surrounding the implant is of utmost significance to determine osseointegrated implant success, as preservation of marginal bone height is highly important for long-term dental implant survival. Various approaches have been described in the literature to prevent the crestal bone loss, including platform switching, non-submerged approach, scalloped implants, implant design modifications, progressive loading, immediate implant placement, etc. The purpose of this paper is to review all the possible methods to preserve the crestal bone, when each method should be used and their success rates in an attempt to address this complex problem of crestal bone resorption. "PubMed" and "Google Scholar" were used to find out any studies involving platform switching concept from 1990 up to 2009. Twenty-four studies involving methods for preservation of crestal bone were evaluated, which included 26% studies on platform switching, 22% on non-submerged approach, 17% on scalloped implants, 13% on progressive loading and 22% on immediate implant placement. Crestal bone preservation should be thought of starting from the design of the implant to be placed. The technique to be followed in a given case will depend upon the density of bone, force factors by the patient, bone volume and amount of soft tissues, etc. The best possible method or the combination of the methods should be used to preserve the crestal bone for the long-term success of the implants.

Nanotechnology in ligature-induced periodontitis: protective effect of a doxycycline gel with nanoparticules

OBJECTIVES: The aim of this study was to test the efficacy of a locally applied 8.5 percent nanostructured doxycycline (DOX) gel in preventing alveolar bone loss in experimental periodontal disease (EPD) in rats by using the tapping mode atomic force microscopy (AFM). MATERIAL AND METHODS: EPD was induced in 24 Wistar rats. Animals were treated with the doxycycline gel topically, immediately after EPD induction, and 3 times a day during 11 days. Four groups (n=6) were formed as follows: Naïve group (animals not subjected to EPD nor treated); non-treated (NT) group (animals subjected to EPD, but not treated); vehicle gel (VG) group (animals subjected to EPD and treated with topical gel vehicle); and DOX group (test group): animals subjected to EPD and treated with the 8.5 percent DOX gel. In order to investigate topographical changes in histological sections, a novel simple method was used for sample preparation, by etching sections from paraffin-embedded specimens with xylol. RESULTS: Comparing the AFM images, several grooves were observed on the surface of the alveolar bone and other periodontal structures in the NT and VG groups, with significantly greater depths when compared to the DOX group (p<0.05). CONCLUSIONS: Periodontal structures were brought into high relief confirming to be a simple and cost-effective method for AFM imaging with ultrastructural resolution. The doxycycline gel was able to afford periodontal surface preservation, with flatter grooves.

Effect of Atorvastatin in radiographic density on alveolar bone loss in wistar rats

The purpose of this study was to evaluate the effect of Atorvastatin (ATV) on alveolar bone loss induced in rats. Periodontitis was induced by ligature placement around the upper second left molar in a total of 24 male Wistar rats (± 200 g). Groups of 6 animals received via oral gavage either saline or ATV (1, 3 and 9 mg/kg) during 11 days. After this time, the animals were sacrificed and their maxillae were removed, defleshed, radiographed by Digora System®, and latter stained to be photographed using a digital camera. Data were analyzed statistically by ANOVA and Bonferroni test at 5 percent significance level and presented as mean ± SEM. ATV (9 mg/kg) caused a significant increase on gray tone variation of over 48 percent (118.3 ± 12.0 gray tones) when compared to saline (79.8 ± 6.2 gray tones), indicating greater radiographic density. These data were corroborated by macroscopic findings, where ATV (9 mg/kg) reduced alveolar bone loss by over 47 percent (p<0.05), when compared to the group of untreated animals (saline). In summary, ATV was able to prevent alveolar bone loss seen on a ligature-induced periodontitis model.

O objetivo deste estudo foi avaliar o efeito da Atorvastatina (ATV) na perda óssea alveolar induzida em ratos. A periodontite foi induzida através da colocação de ligadura ao redor do segundo molar superior esquerdo de um total de 24 ratos Wistar machos (± 200 g). Grupos de 6 animais receberam por via oral solução Salina a 0,9 por cento ou Atorvastatina (1, 3 e 9 mg/kg), por 11 dias, quando então foram sacrificados e suas maxilas foram removidas, dissecadas, radiografadas através do Sistema Digora System®, e fotografados usando câmara digital. Os dados foram expressos como média ± EPM (ANOVA e teste de Bonferroni). Atorvastatina (9 mg/kg) causou aumento significante de aproximadamente 48 por cento na variação de tons de cinza (ATV 9=118,3 ± 12,0 tons de cinza), indicando maior densidade radiográfica, quando comparada ao controle (solução salina =79,8 ± 6,2 tons de cinza). Estes dados foram corroborados pelos achados macroscópicos, onde Atorvastatina (9 mg/kg) reduziu a perda óssea alveolar em 47 por cento (p<0,05), quando comparado aos animais não tratados (solução salina). Em suma, a Atorvastatina preveniu a perda óssea alveolar vista no modelo de periodontite induzida por ligadura.

Quantitative radiographic evaluation of periapical bone resorption in dog's teeth contaminated with bacterial endotoxin (LPS) associated or not with calcium hydroxide

The aim of this study was to quantify radiographically the periapical bone resorption in dogs' teeth contaminated with bacterial endotoxin (LPS), associated or not with calcium hydroxide. After pulp tissue removal, 60 premolars were randomly assigned to 4 groups and were either filled with LPS (group 1), filled with LPS plus calcium hydroxide (group 2) or filled with saline (group 3) for a period of 30 days. In group 4, periapical lesion formation was induced with no canal treatment. Standardized radiographs were taken at the beginning of the treatment and after 30 days and the Image J Program was used for measurement of periapical lesion size. Periapical lesions were observed in groups 1 (average of 8.44 mm2) and 4 (average of 3.02 mm2). The lamina dura was intact and there were no areas of periapical bone resorption in groups 2 and 3. It may be concluded that calcium hydroxide was effective in inactivating LPS, as demonstrated by the absence of apical periodontitis in the roots that were filled with bacterial endotoxin plus calcium hydroxide.

O objetivo deste estudo foi quantificar radiograficamente a reabsorção óssea periapical em dentes de cães contaminados com endotoxina bacteriana (LPS), associadas ou não ao hidróxido de cálcio. Sessenta pré-molares foram divididos em 4 grupos e preenchidos com LPS (grupo 1), LPS e hidróxido de cálcio (grupo 2), solução salina (grupo 3), ou lesões periapicais foram induzidas sem tratamento (grupo 4), por um período de 30 dias e o Programa Image J foi empregado para mensuração das lesões, em mm2. Radiografias foram realizadas no início do tratamento e após 30 dias. Lesões periapicais foram observadas no grupo 1 (média de 8,44 mm2) e 4 (média de 3,02 mm2). A lâmina dura estava intacta e não foram observadas áreas de reabsorção óssea periapical nos grupos 2 e 3. Concluindo, a avaliação radiográfica quantitativa do efeito do LPS associado ao hidróxido de cálcio demonstrou que quando juntos a endotoxina bacteriana é inativada, uma vez que não foram observadas lesões periapicais nas raízes deste grupo experimental.

Selective cyclooxygenase-2 inhibition prevents bone resorption

O objetivo deste trabalho foi avaliar o efeito de um inibidor seletivo da cicloxigenase-2 (COX-2) (meloxicam) na progressão da perda óssea alveolar durante o desenvolvimento da doença periodontal experimental induzida. Quarenta (40) ratos Wistar foram separados em 8 grupos experimentais (n = 5). Ligaduras de fio de algodão foram colocadas na margem gengival do primeiro molar inferior direito de alguns ratos. Quatro grupos foram tratados por 5 ou 15 dias com uma dose oral de 15 mg/kg de peso corporal/dia do inibidor seletivo de COX-2. Os outros grupos foram usados como controle positivo (sham) e controle negativo dentro de cada período experimental. Radiografias digitais padronizadas foram realizadas para medir a perda óssea na região mesial do primeiro molar inferior de cada rato. O efeito do tratamento com meloxicam não induziu alteração de peso ou outras manifestações sistêmicas visíveis. A Análise de Variância (ANOVA) indicou que os grupos tratados com meloxicam após 5 dias apresentaram perda óssea alveolar significativamente menor (p < 0,05). Por outro lado, a perda óssea não foi significativa após 15 dias de tratamento com meloxicam. Os dados apresentados no presente trabalho sugerem que o tratamento sistêmico com meloxicam pode modificar a progressão da periodontite experimental em ratos no período experimental inicial.

Locally produced bovine bone sponge as a haemostatic agent

The aim of this study was to evaluate the morphological and biological properties of a locally produced "Bovine Bone Sponge" for use in dentistry. Bovine bone sponge was prepared from local calf bone. Endotoxin level and surface properties were investigated. The pore size and water uptake ability were measured and results were compared with the commercial haemostatic agent. The material was tested for its haemostatic property and its inhibition of alveolar bone resorption in a sheep model following dental extraction. Results revealed a significant difference in haemostatic effect, and a shorter bleeding time and a lower rate of alveolar bone resorption in bovine bone sponge compare to a commercial haemostatic agent.

Prevención de la pérdida de la dimensión de los procesos alveolares con la colocación del polímero osteoconductor biocompatible / Prevention of the loss of the dimension of the alveolar processes with the placement of the biocompatible osteoconducting polymer

A pesar de los importantes progresos en el campo de la salud oral, la extracción dental todavía es un problema frecuente. Una vez que se extraen los dientes se producen cambios anatómicos en los procesos alveolares, los cuales pueden causar atrofia alveolar grave; ésta es una enfermedad multifactorial que ha sido estudiada por numerosos autores. Con el propósito de prevenir la pérdida de la dimensión de los procesos alveolares, se ha colocado en los alvéolos dentales diversos materiales, la mayor parte de estos tienen la desventaja de que conservan los procesos alveolares por la presencia del implante sin tener influencia fisiológica sobre el hueso. El polímero osteoconductor biocompatible es un material que se ha utilizado como sustituto óseo en diversos procedimeitnos de cirugía ortopédica; estudios histológicos han mostrado crecimiento óseo en los sitios donde ha sido implantado. En este trabajo se colocó el material en los alvéolos dentales de 11 pacientes, inmediatamente después de realizar la extracción dental, con el fin de prevenir la pérdida de la dimensión de los procesos alveolares. Se observó aumento en el espesor y en la altura de los procesos alveolares en 81.9 por ciento y 100 por ciento de los casos, respectivamente