Vertical Bone Augmentation Using Deproteinized Bovine Bone Mineral, Absorbable Collagen Sponge, and Recombinant Human Bone Morphogenetic Protein-2: An In Vivo Study in Rabbits.

PURPOSE: The objective of this investigation was to assess vertical bone augmentation using deproteinized bovine bone mineral (DBBM) infused or not with recombinant human bone morphogenetic protein (rhBMP-2) in rabbit tibiae. MATERIALS AND METHODS: A total of 18 female rabbits (New Zealand) received two blocks of DBBM in each tibia. The DBBM blocks were randomly assigned into four experimental groups: DBBM (only the bone graft); DBBM associated with absorbable collagen sponge (ACS); DBBM plus rhBMP-2 (1.5 mg/mL); and DBBM infused with rhBMP-2 (1.5 mg/mL) in an ACS carrier. Animals were sacrificed after 12 weeks, and the tibiae containing the DBBM blocks were dissected and analyzed radiographically (microcomputed tomography [micro-CT]), histologically, and immunohistochemically. RESULTS: Micro-CT analysis showed a considerable increase in bone volume (BV) and BV/tissue volume in the rhBMP-2/ACS group compared with all the others. Trabeculae thickness also increased in the rhBMP-2/ACS group compared with the DBBM/ACS group. Trabecular number, separation, and bone mineral density were not different among groups. Histomorphometric evaluation showed increased newly formed bone in the rhBMP-2/ACS group compared with the DBBM and DBBM/ACS groups. The amount of residual bone graft was statistically higher in the rhBMP-2 groups compared with the DBBM/ACS group. Immunohistochemical analysis showed that the vascular endothelial growth factor (VEGF) expression was more intense in the rhBMP-2/ACS group compared with the DBBM/ACS group. The immunopositivity for type 1 collagen tended to be higher in the two groups with rhBMP-2. CONCLUSION: Collectively, the results of this study suggest that the addition of rhBMP-2 in an ACS carrier placed on top of the DBBM graft enhanced bone formation in this animal model.

Long-term evaluation of oral gavage with periodontopathogens or ligature induction of experimental periodontal disease in mice.

OBJECTIVE: To evaluate in long-term periods the destruction of periodontal tissues and bacterial colonization induced by oral gavage with periodontopathogens or ligature experimental periodontal disease models. MATERIAL AND METHODS: Forty-eight C57BL/6 J mice were divided into four groups: group C: negative control; group L: ligature; group G-Pg: oral gavage with Porphyromonas gingivalis; and group G-PgFn: oral gavage with Porphyromonas gingivalis associated with Fusobacterium nucleatum. Mice were infected by oral gavage five times in 2-day intervals. After 45 and 60 days, animals were sacrificed and the immune-inflammatory response in the periodontal tissue was assessed by stereometric analysis. The alveolar bone loss was evaluated by live microcomputed tomography and histometric analysis. qPCR was used to confirm the bacterial colonization in all the groups. Data were analyzed using the Kruskal-Wallis, Wilcoxon, and ANOVA tests, at 5 % of significance level. RESULTS: Ligature model induced inflammation and bone resorption characterized by increased number of inflammatory cells and decreased number of fibroblasts, followed by advanced alveolar bone loss at 45 and 60 days (p < 0.05). Bacterial colonization in groups G-Pg and G-PgFn was confirmed by qPCR but inflammation and bone resorption were not observed (p < 0.05). CONCLUSIONS: The ligature model but not the oral gavage models were effective to induce inflammation and bone loss in long-term periods. Pg colonization was observed in all models of experimental periodontal disease induction, independent of tissue alterations. These mice models of periodontitis validates, compliments, and enhances published PD models that utilize ligature or oral gavage and supports the importance of a successful colonization of a susceptible host, a bacterial invasion into vulnerable tissue, and host-bacterial interactions that lead to tissue destruction. CLINICAL RELEVANCE: The ligature model was an effective approach to induce inflammation and bone loss similar to human periodontitis, but the oral gavage models were not efficient in inducing periodontal inflammation and tissue destruction in the conditions studied. Ligature models can provide a basis for future interventional studies that contribute to the understanding of the disease pathogenesis and the complex host response to microbial challenge.

Caracterização das alterações teciduais em dois modelos de indução de doença periodontal experimental em camundongos / Characterization of tissue changes in two models of experimental induction of periodontal disease in mice

A periodontite é uma doença infecciosa caracterizada por um processo inflamatório crônico do periodonto mediada e modulada pelo hospedeiro. Esta patologia resulta na destruição do tecido conjuntivo gengival e dos tecidos de suporte dos dentes. De modo a avaliar tanto a patogênese da doença periodontal quanto as diversas modalidades de tratamento, diferentes modelos animais de periodontite experimental têm sido propostos e utilizados. O benefício do uso destes modelos resulta no fato de que eles permitem uma avaliação da doença de uma forma longitudinal, com características de início e progressão semelhantes em diversos animais. O objetivo deste estudo foi caracterizar e avaliar comparativamente as alterações teciduais provocadas por dois modelos de doença periodontal experimental em camundongos: ligadura e gavagem oral. Para isto, foram utilizados 48 camundongos C57/BL6 wild type (WT), divididos em 4 grupos: Grupo C - Controle negativo, Grupo L ­ Ligadura (indução da doença periodontal por meio de ligaduras), Grupo G-Pg ­ Gavagem de Porphyromonas gingivalis (indução por meio de inoculações de Pg) e Grupo G-PgFn ­ Gavagem de Porphyromonas gingivalis + Fusobacterium nucleatum. Os animais foram sacrificados em dois períodos experimentais: 45 e 60 dias após o início da indução da doença periodontal. Observou-se perda óssea alveolar significativa apenas no grupo L, por meio de análise estereométrica, microtomografia computadorizada(µCT) e imunohistoquímica. A colonização bacteriana nos grupos de gavagem foi confirmada por meio de PCR em tempo real. Concluímos que o modelo de ligadura foi efetivo em induzir a doença periodontal nos parâmetros utilizados ao contrário da gavagem oral

Periodontitis is an infectious disease characterized by a chronic inflammatory process of periodontal mediated and modulated by the host. This disease results in the destruction of conective tissue and supporting tissues of the teeth. In order to evaluate both the pathogenesis of periodontal disease and the various treatment modalities, different animal models of experimental periodontitis have been proposed and used. The benefit of using these models results in the fact that they allow an evaluation of a longitudinal disease with similar characteristics of start and progression in several animals. The aim of this study was to characterize and evaluate tissue changes caused by two models of experimental periodontal disease in mice: ligature and oral gavage. For this, 48 C57/BL6 mice wild type (WT) mice were divided into 4 groups: Group C - Negative Control, Group L - Ligature (induction of periodontal disease by ligatures), Group G-Pg - Porphyromonas gingivalis Gavage (induction by Pg inoculations) and Group G-PgFn - Porphyromonas gingivalis + Fusobacterium nucleatum Gavage. The animals were sacrificed at two experimental periods: 45 and 60 days after the induction onset of periodontal disease. Significant bone loss only in the group L by means of stereometric analysis, computed microtomography (µCT) and immunohistochemistry was observed. The bacterial colonization in groups of gavage was confirmed by PCR in real time. We conclude that the model of ligature was effective in inducing periodontal disease parameters used in contrast to oral gavage

Correlação entre saúde periodontal e idade gestacional / Correlation between periodontal health and gestacional age

Introdução: O baixo peso de recém-nascidos (RN) é considerado um problema de saúde pública e, geralmente, é associado à prematuridade. A etiologia do parto prematuro é bastante complexa e, frequentemente, está relacionada a vários fatores. Diversas teorias têm correlacionado a saúde periodontal de gestantes com o nascimento de bebês prematuros (idade gestacional) e/ou com baixo peso ao nascer. Objetivo: O objetivo do presente estudo foi avaliar a possível correlação de saúde periodontal com idade gestacional e/ou com nascimento de bebês com baixo peso. Material e Método: Estudo observacional longitudinal prospectivo com gestantes que foram atendidas em um projeto de extensão da Universidade Federal do Piauí - Programa Preventivo para Gestantes e Bebês - PPGB. A coleta dos dados foi estruturada em dois momentos: 1º- Preenchimento de ficha contendo dados relativos à saúde geral e exame periodontal completo, e 2º- Coleta de dados referentes a tipo de parto, duração da gestação, peso e condição de saúde do bebê. Resultado: De 62 gestantes atendidas, 43 participaram do segundo momento do estudo. Ocorreu uma predominância de gestantes com idade entre 25 e 35 anos (55,81%). O índice de sangramento gengival variou de 1,19% a 92,50%. A média do peso dos bebês foi 3.365,33 g e do tempo gestacional foi 39,33 semanas. Conclusão: Os resultados deste estudo não deram suporte à hipótese de que a doença periodontal está associada à idade gestacional.

Introduction: The birth of newborn (NB) underweight is considered a public health problem and is often associated with prematurity. The etiology of preterm birth is complex and often is related to several factors. Several theories have correlated the periodontal health of pregnant women with preterm birth (gestational age) and / or with low birth weight. Objective: The objective of this study is to evaluate the possible correlation between periodontal health with gestacional time and/or with low birth weight. Material and Method: A Prospective longitudinal observational study with pregnant women that were attending a extension project of UFPI - Preventive Program for Pregnant Women and Babies - PPPWB. Data collection was structured in two moments: 1st fill sheet containing questions related to health of the pregnant woman, complete clinical and periodontal examination of the oral cavity and 2nd data collection on the type of delivery, gestation length, baby's weight and health condition. Result: A total of 62 pregnant women were attended and only 43 patients participated in the second moment of the study. There was a predominance of women aged between 25 to 35 years (55.81%). The bleeding index ranged from 1.19% to 92.50%. The average weight of infants was 3365.33 g and gestational time was 39.33 weeks. Conclusion: The results of this study did not support the hypothesis that periodontal disease is associated with gestacional time and/or low birth weight.