Evaluation of 2 techniques of epithelial removal in subepithelial connective tissue graft surgery: a comparative histological study.

PURPOSE: Subepithelial connective tissue grafts (SCTGs) are commonly performed for the treatment of gingival recession due to their high predictability. This study evaluated and histologically compared connective tissue grafts in terms of the presence of epithelial remnants and composition of the tissue types that were present (epithelium, lamina propria, and submucosa). METHODS: Ten patients underwent epithelium removal using 2 different techniques: the use of a blade (group B) and through abrasion (group A). Twenty samples were collected and each tissue type was analyzed histologically in terms of its area, thickness, and proportion of the total area of the graft. RESULTS: In 4 samples (40%) from group B (n=10) and 2 samples (20%) from group A (n=10), the presence of an epithelial remnant was observed, but the difference between the groups was not statistically significant (P>0.05). Likewise, no statistically significant differences were observed between the groups regarding the area, mean thickness, or proportion of the total area for any of the tissue types (P>0.05). CONCLUSIONS: Histologically, SCTGs did not show statistically significant differences in terms of their tissue composition depending on whether they were separated from the epithelial tissue by abrasion or by using a blade.

Evaluation of intracanal acetazolamide in late reimplanted rat teeth.

OBJECTIVE: The aim of this study was to evaluate the use of acetazolamide combined with different agents as intracanal medication in late reimplanted rat teeth. MATERIALS AND METHODS: In 100 Wistar rats, divided into 5 groups of 20, one of the following medications was used: Acetazolamide liquid (AL); AL with calcium hydroxide powder (ALHC); acetazolamide powder with AL; acetazolamide powder with physiological solution; and calcium hydroxide with physiological solution (control). At 30 and 60 days after reimplantation, the animals were sacrificed, tissues were processed, and cuts were stained with hematoxylin and eosin. An optical microscope was used to determine the following: percentage of inflammatory root resorption (RRI); percentage of substitute root resorption (RRS); and presence of ankylosis. The data obtained was submitted for statistical analysis. RESULTS: Group ALHC had a significantly higher RRS than the control group at 60 days (P = 0.01). Group AL showed significantly less ankylosis than the other groups, including the control, at 30 days. AL showed results similar to those of the control group with respect to RRS. CONCLUSION: Acetazolamide has the potential to be an effective intracanal medication.

Tissue responses resulting from tooth movement surgically assisted by corticotomy and corticision in rats.

OBJECTIVE: To compare the histological responses in corticotomy- and corticision-assisted tooth movement. MATERIALS AND METHODS: Ninety Wistar rats were divided into three groups: C (control-tooth movement only), CT (tooth movement + corticotomy), and CI (tooth movement + corticision). Surgeries were performed on the vestibular and lingual cortical bone of the maxillary first molar. Tooth movement was carried out with nickel-titanium closed coil springs having a force of 30 g. The rats were sacrificed at 3, 14, and 28 days. To evaluate the number of osteoclasts and amount of root resorption, a tartrate-resistant acid phosphatase stain was used. Hematoxylin and eosin staining was performed for areas of hyalinization, and the organic bone matrix was stained with picrosirius. RESULTS: The CT group showed a greater number of osteoclasts than did the C group on day 3 (P < .05). At the same time point, the CT and CI groups showed a delayed onset of organic bone matrix remodeling and a lower incidence of root resorption than did the C group (P < .05). There were also fewer hyalinization areas in the CI group than in the C group on day 3 (P < .05). CONCLUSIONS: Corticotomy effectively increased bone resorption during the early stages of tooth movement, but this increase was not observed for corticision. The surgical procedures did not accelerate organic bone matrix remodeling. Corticotomies and corticisions decreased the risk of root resorption only during the early stages of movement. Corticision reduced the level of hyalinization, while corticotomy did not.

Efeito da deficiência de estrógeno no preenchimentode defeitos ósseos tratados ou não com biomaterial:um estudo radiográfico em ratas / The effect of estrogen deficiency on filling bone defects treated or not with biomaterial: a radiographic study on rats

Objetivos: O objetivo deste estudo foi avaliar radiograficamente o preenchimento ósseo de defeitos criados em tíbia de ratas ovariectomizadas e não ovariectomizadas, preenchidos por coágulo ou material substituto ósseo. Materiais e métodos: Foram utilizadas 30 ratas wistar, sendo que 15 foram ovariectomizadas(grupo OV) e 15 ratas não receberam ovariectomia (grupo NOV). Decorridos 60 dias da cirurgia de ovariectomia,ambos os grupos foram submetidos à cirurgia para confecção de defeitos ósseos nas tíbias. A tíbia direita foi preenchida por coágulo, e a esquerda, por biomaterial sintético (Bone Ceramic®), formando os seguintes grupos: grupos não ovariectomizados com defeitos preenchidos por coágulo (grupo NOV/C) ou por biomaterial (grupo NOV/B), e grupos ovariectomizados com defeitos preenchidos por coágulo (grupoOV/C) ou por biomaterial (grupo OV/B). Decorridos 60 dias da cirurgia de confecção dos defeitos e seus preenchimentos, as ratas foram mortas e suas tíbias removidas. A densidade óssea das tíbias foi avaliada em radiografias digitais e as imagens foram estudadas no programa de imagem ImageJ, por examinador único.Para a análise estatística, utilizou-se o teste Anova a dois critérios multifatoriais completos com α < 0,05.Resultados: A porcentagem média de preenchimento ósseo para cada grupo foi: grupo NOV/C, 71,55%;grupo NOV/B, 70,44%; grupo OV/C, 21,03% e grupo OV/B, 58,93%. Conclusão: Com base nos resultados par obtidos,pôde-se concluir que a deficiência de estrógeno interferiu no grau de preenchimento ósseo em defeitos cirurgicamente criados em tíbias de ratas, com ou sem o uso de um biomaterial.

Objectives: The aim of this study was to evaluate radiographically the bone filling of defects surgically createdin the tibiae of ovariectomized and non-ovariectomized rats. Defects were filled with coagulum or syntheticbone graft. Materials and methods: Thirty female Wistar rats were divided into two groups: 15 rats receivedovariectomy (group OVX) and 15 did not (group NOVX). Sixty days after ovariectomy surgery, both groups weresubmitted to ostectomy surgery for bone defect creation in the tibiae. The right tibiae were filled with coagulumand the left one with synthetic bone graft (Bone Ceramic®). The groups of study were: non--ovariectomizedgroup, with defects filled with coagulum (group NOV/C) or biomaterial (group NOV/B), and ovariectomizedgroup, with defects filled with coagulum (group OV/C) or biomaterial (group OV/B). After 120 days, the ratswere sacrificed and their tibiae removed. The bone density was evaluated by digital radiograph and the imageswere analyzed by ImageJ program. In order to carry out the statistical analysis, Anova test was applied α <0.05. Results: The mean percentages of bone filling for each group were: group NOV/C, 71.55%; group NOV/B,70.44%; group OV/C, 21.03% and group OV/B, 58.93%. Conclusion: Based on the results obtained, it was possibleto conclude that estrogen deficiency interfered on the level of bone filling of surgically created defects inrats tibiae, with or without the use of biomaterial.

Radiographic evaluation of the effect of porcine submucosamembrane graft and bioactive glass on bone filling in rat calvaria / Avaliação radiográfica do efeito de membrana de submucosa suína e vidro bioativo no preenchimento ósseo em calvária de rato

Objectives: The aim of this study was to radiographically evaluate the filling of standardized bone defectsin rat calvaria treated with bioactive glass and with porcine submucosa membrane, alone or in combination,when compared to defects filled with clot. Materials and methods: Eighty male Wistar rats, weighing 250to 300 g, were divided into four groups, with trial period of two and eight weeks. Standardized bone woundswere surgically created in the calvaria measuring 6 mm in diameter and treated with bioactive glass, porcinesubmucosa membrane, combination of both or only clot. After two or eight weeks, the animals wereeuthanized and bone specimens were collected for evaluation with standard radiographs and digitized foranalysis with ImageJ image analyzer to compare the percentage of filling of the defects by measuring thevariations of levels of gray. Data were scored and analyzed statistically (ANOVA and Tukey HSD, p < 0.05).Results: The association of bioactive glass and submucosa membrane showed the best result of filling ofbone cavities, followed by the single use of bioactive glass. Membrane alone showed similar results withthe clot group. Conclusion: It was possible to conclude that the association of bioactive glass and porcinesubmucosa membrane could be good option for bone filling of bone defects.

Objetivos: O objetivo deste estudo foi avaliar radiograficamente o preenchimento de defeitos ósseos padronizados em calvária de ratos, tratados com vidro bioativo e com membrana de submucosa suína, isolados ou em associação, quando comparados com defeitos preenchidos com coágulo. Materiais e métodos: Oitenta ratos Wistar machos, pesando de 250 a 300 g, foram separados em quatro grupos, com períodos de avaliação de duas ou oito semanas. Defeitos ósseos padronizados foram cirurgicamente criados na calvária medindo 6 mm de diâmetro e tratados com vidro bioativo, membrana submucosa suína, combinação de ambos ou apenas com coágulo. Após duas ou oito semanas, os animais foram mortos e os espécimes ósseos foram coletados para avaliação com radiografias padronizadas e digitalizadas para análise com programa ImageJ, visando a comparar a porcentagem de preenchimento dos defeitos por meio da variação dos níveis de cinza. Os dados foram obtidos e avaliados estatisticamente (ANOVA e Tukey HSD, p < 0,05). Resultados: A associação do vidro bioativo com a membrana submucosa suína demonstrou os melhores resultados de preenchimento das cavidades ósseas,seguido pelo uso isolado do vidro bioativo. A membrana isolada demonstrou resultados semelhantes ao grupo coágulo. Conclusão: Foi possível concluir que a associação do vidro bioativo e da membrana submucosa suína pode ser uma boa opção para o preenchimento de defeitos ósseos.

Rapid orthodontic extrusion using an interocclusal appliance for the reestablishment of biologic width: a case report.

A multidisciplinary treatment of a case of subgingival fracture in a maxillary anterior tooth is presented. This case report describes a simple method involving an interocclusal appliance and an elastic band for rapid orthodontic extrusion to reestablish biologic width. In addition, a simple technique for surgical recontouring following the coronal displacement of the gingival margin prior to restoration of fractured tooth is explained.

Comparação entre duas técnicas para enxerto de tecido conjuntivo em recessões classes l ou ll de Miller / Comparison between two techniques of connective tissue grafting in Miller recession Class I and II

A recessão gengival é uma condição bastante comum entre pacientes de ambos os sexos e em diferentes idades, aumentando sua frequência com o passar dos anos. As maiores queixas dos pacientes com recessão gengival são hipersensibilidade radicular e aspecto antiestético. Para isto, existem diversos tratamentos, sendo as cirurgias de enxerto as mais utilizadas. Atualmente, o tratamento mais indicado para estes casos são os enxertos de tecido conjuntivo associados a alguma técnica de retalho. Este trabalho visou comparar apenas em recessões profundas, Classes I ou II de Miller, se existiam diferenças entre enxertos realizados com a técnica do envelope e a técnica do retalho posicionado apicalmente (RPA). Optou-se por estas técnicas, já que no envelope parte do enxerto fica exposto e no RPA ele é recoberto e um dos parâmetros avaliados foi o ganho de tecido ceratinizado após os atos cirúrgicos. Concluiu-se que ambas são igualmente satisfatórias quanto a recobrimento neste tipo de recessão, tendo a técnica do envelope um ganho maior de tecido ceratinizado, além de ter a cicatrização mais rápida.

Orthodontic extrusion and implant site development using an interocclusal appliance for a severe mucogingival deformity: a clinical report.

A multidisciplinary therapy used to treat a patient with a severe mucogingival deformity in the area of maxillary anterior teeth is presented. The simple technique uses an interocclusal appliance and elastic band for orthodontic extrusion to correct the mucogingival deformity and develop an implant site. This approach is designed to increase the amount of keratinized tissue and new alveolar bone, which are necessary for the development of an implant site. Clinical and radiographic examinations at the 5-year follow-up revealed a successful tooth replacement and improved esthetic appearance that was achieved with multidisciplinary treatment. The advantages and disadvantages of this technique are discussed.

Bismuth subgallate as a topical hemostatic agent at palatal donor sites.

OBJECTIVE: To present bismuth subgallate as a simplified and efficient method for promoting hemostasis at palatal donor sites, as evaluated by measuring hemostasis time and delayed bleeding. METHOD AND MATERIALS: Ten patients received the bismuth subgallate paste as a topical hemostatic agent, while another 10 patients received moistened gauze pressure. The time to obtain complete hemostasis, defined as no visual bleeding, was recorded for each subject. RESULTS: Bismuth subgallate paste was found to decrease hemostasis time, when compared with moistened gauze pressure. The mean hemostasis time for the bismuth subgallate group was significantly shorter (2.6 +/- 0.7 minutes) when compared to the moistened gauze group (7.2 +/- 1.4 minutes). While delayed bleeding was observed in the moistened gauze group, no statistically significant difference was found between the groups (P = .10). CONCLUSION: The use of bismuth subgallate as a topical hemostatic for palatal wounds may be an option when performing free soft tissue grafts.

The relationship between interimplant distances and vascularization of the interimplant bone.

BACKGROUND: Long-term success of the implant restorations is based upon the biology and vasculature of the bone surrounding the implants, especially for the bone between two implants. PURPOSE: The aim of this study was to evaluate how loaded implants placed 2 or 3 mm apart influence bone vessel organization. MATERIAL AND METHODS: Six mongrel dogs were used for the study. The four mandibular premolars were extracted and 3 months later, four 4.5 x 10 mm implants were placed on each side of the mandible. The implants were placed so that two adjacent implants were 2 mm (group 1) or 3 mm (group 2) distant from each other. After 12 weeks, the implants were loaded with provisional prostheses, then metallic crowns were placed 4 weeks later. Both temporary and metallic restorations were made so that the distance between the contact point and the bone crest was 5 mm. The animals were sacrificed after 8 weeks. The hemi-mandibles were removed and prepared for analysis. The interimplant bone vasculature of the two groups was studied using scanning electron microscopic images fractal analysis. The fractal dimension (D(f)) was calculated using the box-counting method. RESULTS: The values of the D(f) for the blood vessels were significantly higher (P<.05) in the specimens of the group 2 (1.969+/-0.169) than the group 1 (1.556+/-0.246). CONCLUSION: The presence of more blood vessels in the group 2 is another indication that 3 mm is a preferable distance for contiguous implants than the 2 mm distance.

Effect of biofunctionalized implant surface on osseointegration: a histomorphometric study in dogs.

Among the different properties that influence bone apposition around implants, the chemical or biochemical composition of implant surface may interfere on its acceptance by the surrounding bone. The aim of this study was to investigate if a biofunctionalization of implant surface influences the bone apposition in a dog model and to compare it with other surfaces, such as a microstructured created by the grit-blasting/acid-etching process. Eight young adult male mongrel dogs had the bilateral mandibular premolars extracted and each one received 6 implants after 12 weeks, totaling 48 implants in the experiment. Four groups of implants were formed with the same microrough topography with or without some kind of biofunctionalization treatment. After histomorphometric analysis, it was observed that the modified microstructured surface with a 'low concentration of the bioactive peptide' provided a higher adjacent bone density (54.6%) when compared to the other groups (microstructured + HA coating = 46.0%, microstructured only = 45.3% and microstructured + 'high concentration of the bioactive peptide' = 40.7%), but this difference was not statistically significant. In conclusion, biofunctionalization of the implant surface might interfere in the bone apposition around implants, especially in terms of bone density. Different concentrations of bioactive peptide lead to different results.

Bone remodeling adjacent to Morse cone-connection implants with platform switch: a fluorescence study in the dog mandible.

PURPOSE: The aim of this study was to evaluate, through fluorescence analysis, the effect that different interimplant distances, after prosthetic restoration, will have on bone remodeling in submerged and nonsubmerged implants restored with a "platform switch." MATERIALS AND METHODS: Fifty-six Ankylos implants were placed 1.5 mm subcrestally in seven dogs. The implants were placed so that two fixed prostheses, with three interimplant contacts separated by 1-mm, 2-mm, and 3-mm distances, could be fabricated for each side of the mandible. The sides and the positions of the groups were selected randomly. To better evaluate bone remodeling, calcein green was injected 3 days before placement of the prostheses at 12 weeks postimplantation. At 3 days before sacrifice (8 weeks postloading), alizarin red was injected. The amounts of remodeled bone within the different interimplant areas were compared statistically before and after loading in submerged and nonsubmerged implants. RESULTS: Statistically significant differences existed in the percentage of remodeled bone seen in the different regions. Mean percentages of remodeled bone in the submerged and nonsubmerged groups, respectively, were as follows: for the 1-mm distance, 23.0% +/- 0.05% and 23.1% +/- 0.03% preloading and 27.0% +/- 0.03% and 25.2% +/- 0.04% postloading; for the 2-mm distance, 18.2% +/- 0.05% and 18.1% +/- 0.04% preloading and 21.3% +/- 0.07% and 19.9% +/- 0.03% postloading; for the 3-mm distance, 18.3% +/- 0.03% and 18.3% +/- 0.03% preloading and 18.8% +/- 0.04% and 19.8% +/- 0.04% postloading; for distal-extension regions, 16.6% +/- 0.02% and 17.4% +/- 0.04% preloading and 17.0% +/- 0.04% and 18.4% +/- 0.04% postloading. CONCLUSIONS: Based upon this animal study, loading increases bone formation for submerged or nonsubmerged implants, and the interimplant distance of 1 mm appears to result in more pronounced bone remodeling than the 2-mm or 3-mm distances in implants with a "platform switch."

Effect of biofunctionalized implant surface on osseointegration: a histomorphometric study in dogs

Among the different properties that influence bone apposition around implants, the chemical or biochemical composition of implant surface may interfere on its acceptance by the surrounding bone. The aim of this study was to investigate if a biofunctionalization of implant surface influences the bone apposition in a dog model and to compare it with other surfaces, such as a microstructured created by the grit-blasting/acid-etching process. Eight young adult male mongrel dogs had the bilateral mandibular premolars extracted and each one received 6 implants after 12 weeks, totaling 48 implants in the experiment. Four groups of implants were formed with the same microrough topography with or without some kind of biofunctionalization treatment. After histomorphometric analysis, it was observed that the modified microstructured surface with a "low concentration of the bioactive peptide" provided a higher adjacent bone density (54.6 percent) when compared to the other groups (microstructured + HA coating = 46.0 percent, microstructured only = 45.3 percent and microstructured + "high concentration of the bioactive peptide" = 40.7 percent), but this difference was not statistically significant. In conclusion, biofunctionalization of the implant surface might interfere in the bone apposition around implants, especially in terms of bone density. Different concentrations of bioactive peptide lead to different results.

Entre as diferentes propriedades de uma superfície capazes de influenciar a deposição óssea ao redor de implantes, a composição química e bioquímica pode atuar no reconhecimento do tecido ósseo circundante. O presente trabalho investigou a influência da biofuncionalização de superfícies de implante na deposição óssea ao redor dos mesmos em um modelo animal, comparando-as com outras superfícies, como a microtexturizada obtida pelo processo de jateamento e ataque ácido. Metodologicamente, os pré-molares mandibulares bilaterais de 8 cães foram extraídos e após 12 semanas foram instalados 6 implantes em cada cão, constituindo uma amostra de 48 implantes. Dos 4 grupos experimentais de diferentes superfícies, todos continham a mesma microtopografia rugosa, porém possuindo ou não alguma biofuncionalização. A análise histomorfométrica revelou que a superfície microtexturizada modificada pela adição de baixa concentração peptídica obteve uma maior densidade óssea adjacente (54,6 por cento) quando comparada aos outros grupos (microtexturizada + HA = 46 por cento, somente microtexturizada = 45,3 por cento e microtexturizada com adição de alta concentração peptídica = 40,7 por cento), no entanto estas diferenças numéricas não foram estatisticamente significantes. Dentro deste contexto, conclui-se que a biofuncionalização da superfície de implantes pode interferir na aposição óssea, em particular na densidade óssea, e que diferentes concentrações peptídicas podem conduzir a diferentes resultados.

Efeito de agentes para desmineralização sobre a rugosidade da superfície radicular / The effect of deminarization agents on the root surface roughess

O objetivo da instrumentação periodontal é remover depósitos calcificados, placa e endotoxinas bacterianas, criando uma superfície lisa e descontaminada. Para isso, a instrumentação mecânica torna-se imprescindível, podendo ser associada à utilização de agentes para desmineralização da superfície radicular. Visto que não há trabalhos na literatura avaliando o efeito da utilização desses agentes sobre a rugosidade radicular, este estudo utilizou 40 dentes humanos monorradiculares extraídos, sendo divididos aleatoriamente em quatro grupos de dez dentes, sendo os mesmos instrumentados com 30 golpes de curetas de Gracey 5/6. Os dentes foram então seccionados no sentido longitudinal e separados em duas metades, sendo que cada uma delas foi sorteada para receber um dos tratamentos (ácido cítrico pH1 ou Edta 24% ou ácido fosfórico 37% ou salina). Após a aplicação dos tratamentos, cada metade tratada foi analisada em um rugosimento junto com seu homólogo controle (só instrumentado). Os resultados demonstraram não haver diferença estatisticamente significante (teste "t" Student, p<0,05) entre os grupos tratados e os respectivos controles; também não se observou diferenças significativas entre os tratamentos (Anova). Dentro dos limites do presente estudo, pôde-se concluir que os agentes utilizados para desmineralização não alteraram significativamente a rugosidade radicular em comparação com a instrumentção mecânica isoladamente e que também não houve diferença entre as substancias testadas com à relação à rugosidade da superficie radicular.

Influence of interimplant distance on bone microstructure: a histomorphometric study in dogs.

The microstructure of the crestal alveolar bone is important for both the maintenance of osseointegration and the location of the gingival soft tissues. The aim of this study was to evaluate and compare the bone microstructure of the alveolar bone and of the interimplant bone in implants inserted at different interimplant distances. The mandibular bilateral premolars of six dogs were extracted, and after 12 weeks, each dog received eight implants, for a total of 48 implants. Two pairs of implants, one for each hemiarch, were separated by 2 mm (group 1) and by 3 mm (group 2). After 12 weeks, the implants received temporary acrylic prostheses. After four more weeks, metallic crowns substituted the temporary prostheses. After an additional 8 weeks the animals were sacrificed and the hemimandibles were removed, dissected, and processed. The longitudinal collagen fiber orientation was 43.2% for the alveolar bone; it was 30.3% for the 2-mm group and 43.9% for the 3-mm group. There was a statistically significant difference between the 2-mm and 3-mm groups (p < .05). The orientation of transverse collagen fibers was 47.8% for the alveolar bone; it was 37.3% for the 2-mm group and 56.3% for the 3-mm group. There was a statistically significant difference between the 2-mm and 3-mm groups (p < .05). The marrow spaces were 34.87% for the alveolar bone, 52.3% for the 2-mm group, and 59.9% for the 3-mm group. There was a statistically significant difference between the alveolar bone and the 3-mm group (p < .05). The low mineral density index was 36.29 for the alveolar bone, 46.76 for the 2-mm group, and 17.91 for the 3-mm group. There was a statistically significant difference between the 2-mm and 3-mm groups (p < .05). The high mineral density was 87.57 for the alveolar bone, 72.58 for the 2-mm group, and 84.91 for the 3-mm group. There was a statistically significant difference between the alveolar bone and the 2-mm group (p < .05). The collagen fiber orientation resulted in statistically significant differences in both the 2-mm and 3-mm groups compared with the alveolar bone. The marrow spaces appeared significantly increased in the 3-mm group compared with the alveolar bone. The low mineral density index was significantly higher in the 2-mm group, while the high mineral density index was significantly higher in the alveolar bone. In conclusion, the interimplant distance should not be less than 3 mm.

Histological and histomorphometric analysis of the bone-screw interface in the mandibular body after using a 2.0-mm miniplate system: an experimental study in dogs.

PURPOSE: To evaluate the bone-screw interface in a 2.0-mm miniplate system used for rigid internal fixation (RIF). MATERIALS AND METHODS: Nine adult mongrel dogs were subjected to unilateral continuous defect through an osteotomy between the lower third and fourth premolars. The control contralateral side remained untreated. Two 4-hole miniplates were placed bilaterally according to the Arbeitgeimeinschaft für Osteosynthesefragen manual. Miniplates adapted to the alveolar processes were fixed monocortically with 6.0-mm-long titanium alloy screws, whereas miniplates placed near the mandible base were fixed bicortically. At 2, 6, and 12 weeks, mandible segments enclosing the RIF were removed, fixed in formalin, ground-sectioned, and stained with toluidine blue. Under conventional light microscopy, proportions of bone-to-screw contact (BSC) were determined, and data were compared by analysis of variance. RESULTS: At 2 weeks, for both groups, the area between threads exhibited necrotic bone with multiple cracks and absence of bone cells and blood vessels. At 6 and 12 weeks, new Haversian systems progressively replaced necrotic bone. At each time point, no significant differences were seen between screws placed in the same miniplate or between groups. The proportions of BSC were statistically similar at 2 and 6 weeks and lower at 12 weeks. CONCLUSION: The results suggested that in this model, osteotomy did not significantly alter bone repair adjacent to the screw surface.

Análise bioquímica do fluido salivar de indivíduos portadores de doença periodontal / Biochemical analysis of saliva of subjects with periodontal disease

A doença periodontal está associada ao acúmulo local de biofilme. É uma infecção de origem microbiana que, além da destruição de tecidos periodontais, formação de cálculo dentário e perda de dentes, provoca doenças sistêmicas. A saliva é um fluido de origem glandular que recobre as superfícies bucais e possui propriedades físico-químicas extremamente variadas. O objetivo deste estudo foi avaliar se a doença periodontal é capaz de induzir alterações na composição do fluido salivar. Participaram da pesquisa 40 indivíduos, divididos em dois grupos de 20 pessoas: grupo-controle (GC n = 20) e grupo-teste (GT n = 20); neste as pessoas eram portadoras de doença periodontal. Avaliaram se os seguintes parâmetros salivares: capacidade de tamponamento salivar, velocidade do fluxo salivar, pH, concentrações de cálcio, uréia e proteínas totais. Os valores médios e o desvio-padrão obtidos foram: pH ­ GC 7,43 (± 0,62), GT 8,1 (± 0,49); fluxo salivar ­ GC 1,21 (± 0,23), GT 1,01 (± 0,75); cálcio ­ GC 4,7 (± 1,2), GT 5,4 (± 0,85); uréia ­ GC 30,7 (± 9,6), GT 38,6 (± 19,9); proteínas totais ­ GC 355,5 (± 256,7), GT 299,2 (± 132,4). Observou-se uma elevação significativa na quantidade de uréia e cálcio na saliva dos indivíduos portadores de doença periodontal. No entanto a quantidade de proteínas totais na sua saliva diminuiu, sugerindo uma mudança na microbiota bucal. O pH salivar dos portadores de doença periodontal é ligeiramente maior do que o do GT. Fluxo salivar e capacidade de tamponamento salivar foram considerados normais em ambos os grupos.

The most common diseases of periodontal tissues are inflammatory processes of gum and insertion of teeth normality associated to the local accumulation of teeth biofilm. The objective of this search is evaluating if the periodontal diseases are able to induce qualitative and quantitative alteration in saliva of subjects with periodontal diseases. Forty subjects, divided in 2 groups of 20, being one the control group (CG) and the other the test group (TG), based on age and sex were evaluated. There were analyzed the following salivary parameters: capacity of buffer, salivary flow speed, pH, calcium, urea and total proteins concentrations. The medium values and standard directions were: pH: CG 7.43 (± 0.62), TG 8.1 (± 0.49); salivary flow CG 1.21 (± 0.23); TG 1.01 (± 0.75); calcium CG 4.7 (± 1.2), TG 5.4 (± 0.85); urea CG 30.7 (± 9.6), TG 38.6 (± 19.9); total proteins CG 355.5 (± 256.7), TG 299.2 (± 132.4). Significant rise in the amount of urea and calcium in the saliva of the periodontal disease individuals was observed whereas the amount of total proteins in the saliva of these individuals diminished, suggesting a change in microbiota. Salivary pH in the individuals of the TG is slightly higher of that of the CG. Salivary flow and capacity of buffer have been considered normal in both groups.

The effect of bone condensation and crestal preparation on the bone response to implants designed for immediate loading: a histomorphometric study in dogs.

PURPOSE: The aim of this study was to evaluate the influence of bone condensation and crestal preparation on the bone response of implants designed to promote osseocompression. MATERIALS AND METHODS: In the first phase, the mandibular premolars of 6 dogs were extracted bilaterally. After 8 weeks, each dog received 8 Xive implants (4 per hemimandible). One hemimandible was randomly assigned to the experimental group and the other to the control group. The implant site was prepared using conventional standard drills. Prior to implant placement the crestal drill was used in the experimental group but not in the control group. After 12 weeks, the animals were sedated and sacrificed. The hemimandibles were removed and prepared for histomorphometric analysis of bone-implant contact (BIC) and bone density of areas adjacent to and further from the implant surface. RESULTS: The mean +/- SD percentages of BIC attained were 71.1% +/- 11.8% and 45.1% +/- 16.1% for the experimental and control groups, respectively. The bone density analysis revealed that in the control group, percentage BIC was a mean of 55.6% +/- 11.3% adjacent to the implant and 50.7% +/- 17.9% distant from the implant. In the experimental group, percentage BIC was a mean of 71.1% +/- 8.6% adjacent to the implant and 55.6 +/- 11.3 distant from the implant. The difference between the experimental and control groups was statistically significant for both parameters, BIC and bone density, in the adjacent areas (P < .0001). CONCLUSION: Crestal preparation is of fundamental importance for this implant system, since it led to better bone response, represented by the improved BIC and bone density.

Análise histométrica dos tecidos formados em defeitos crónicos de rebordo alveolar de cães com diferentes biomateriais / Histometric analysis of tissues formed on canine alveolar ridge chronic defects with different biomaterials

O objetivo deste trabalho foi quantificar histometricamente os tecidos formados em defeitos crónicos de rebordo alveolar classe III em cães utilizando diferentes biomateriais: osso liofilizado desmineralizado (DFDBA), peptídeo sintético de união celular com matriz óssea bovina inorgânica (P-15/ABM), hidroxíapatita sintética reabsorvível (HA) e vidro bioativo (BG), associados ou não à membranas reabsorvíveis (MR) ou não-reabsorvíveis (M). As amostras constaram de 14 lâminas obtidas de trabalhos anteriores (SMUKLER et ai., 1995 e BARBOZA et ai. 2002). O programa Image já foi utilizado para a quantificação dos diferentes componentes estruturais do teci-do neoformado. Os resultados para o volume ósseo trabecular (VOT) foram de 53,00%, 52,90%, 60,30%, 55,10%, 49,50% e 46,20% para os grupos DFDBA/MR, DFDBA/M, P-15/ABM/ MR, P-15/ABM, HA e BG, respectivamente. Em relação à quantidade de biomaterial residual (BR) os resultados apresentaram 23,60% para o DFDBA/MR, 22,80% para o DFDBA/M, 13,60% para o P-15/ABM/MR, 11,40% para o P-15/ABM, 18,00% para a HA e 11,80% para o BG. Na formação de tecido conjuntivo (TC), os grupos DFDBA/MR, DFDBA/M, P-l 5/ABM/MR, P-l 5/ ABM, HA e BG apresentaram, respectivamente, valores percentuais de23,40%, 24,50%, 26,10%, 33,50%, 32,40% e 41,90%. Nos sítios controle (sem biomaterial), 36,70% correspondeu ao VOT e 63,30% ao TC. Concluímos que os biomateriais P-l 5/ABM e DFDBA, associados a membranas, mostraram melhores resultados de formação óssea, podendo ter aplicação clínica em implantodontia. Em relação à quantidade do biomaterial residual, estudos utilizando diferentes tempos de avaliação ainda são necessários