Connective tissue graft as a biological barrier for guided tissue regeneration in intrabony defects: a histological study in dogs.

BACKGROUND: The use of the autogenous periosteal graft as biological barrier has been proposed for periodontal regeneration. The aim of this study was to evaluate the histometric findings of the subepithelial connective tissue graft as barrier in intrabony defects compared to a bioabsorbable membrane. METHODS: Three-walled intrabony defects were created surgically in the mesial aspect of the right and left maxillary canines in five healthy mongrel dogs. The defects were chronified, and two types of barriers were randomly carried out for guided tissue regeneration in a split-mouth design: the test group with a subepithelial connective tissue graft and the control group with a bioabsorbable membrane. The specimens were processed for histometric analyses of the epithelium (E), connective tissue (CT), newly formed cementum (NC), new bone (NB), and total newly formed tissues (NFT). RESULTS: The test side showed smaller mean of NC (3.6 ± 1.2), NB (2.1 ± 0.7), and NFT (7.7 ± 0.8) than the control group (NC 7.3 ± 0.5; NB 5.3 ± 1.3; NFT 10.1 ± 2.2; P < 0.05). No statistically significant differences were verified for E (test 3.1 ± 2.0; control 2.8 ± 2.1; P > 0.05) and CT (test 2.5 ± 1.1; control 2.0 ± 0.5; P > 0.05) between groups. CONCLUSION: The bioabsorbable membrane was more effective in maintaining the space for periodontal regeneration than periosteal connective graft when used as barrier. CLINICAL RELEVANCE: The bioabsorbable membrane showed more favorable regenerative results in intrabony defects in dogs than the subepithelial connective tissue graft as biological barrier.

Bioactive glass for alveolar ridge augmentation.

The restoration and recovery of the alveolar healing process are a challenge to dental surgeons to achieve satisfactory results at the osseointegration of implants and implant rehabilitation. Different operative technique and biomaterials are being used to reconstruct the framework of the alveolar process. One of the biomaterials used for this purpose is the bioactive glass. The aim of this study was to report clinical and histologic final results of 7 clinical reports of alveolar ridge augmentation using bioactive glass. Clinically, bioglass was able to maintain bone architecture of the alveolar bone and repaired satisfactory. Biopsy was performed on the histologic samples and showed bone formation in intimate contact to the particles of the biomaterial.

Histomorphometric evaluation of human sinus floor augmentation healing responses to placement of calcium phosphate or Ricinus communis polymer associated with autogenous bone.

BACKGROUND: Prosthetic rehabilitation of the posterior maxilla with dental implants is often difficult because of proximity to the maxillary sinus and insufficient bone height. Maxillary sinus floor augmentation procedures aim to obtain enough bone with an association between biomaterials and autogenous bone. PURPOSE: The purpose of this study was to evaluate histomorphometrically two grafting materials (calcium phosphate and Ricinus communis polymer) used in maxillary sinus floor augmentation associated with autogenous bone. MATERIALS AND METHODS: Biopsies were taken from 10 consecutive subjects (mean age 45 years) 10 months after maxillary sinus floor augmentation. The sinus lift was performed with a mixture of autogenous bone and R. communis polymer or calcium phosphate in a 1:2 proportion. Routine histologic processing and staining with hematoxylin and eosin were performed. RESULTS: The histomorphometric analysis indicated satisfactory regenerative results in both groups for a mean of bone tissue in the grafted area (44.24 +/- 13.79% for the calcium phosphate group and 38.77 +/- 12.85% for the polymer group). Histologic evaluation revealed the presence of an inflammatory infiltrate of mononuclear prevalence that, on average, was nonsignificant. The histologic sections depicted mature bone with compact and cancellous areas in both groups. CONCLUSION: The results indicated that both graft materials associated with the autogenous bone were biocompatible, although both were still present after 10 months.

Apical Transportation, Centering Ability, and Cleaning Effectiveness of Reciprocating Single-file System Associated with Different Glide Path Techniques.

INTRODUCTION: The aim of this study was to evaluate the apical transportation, the centering ability, and the cleaning effectiveness of a reciprocating single-file system associated to different glide path techniques. METHODS: The mesial root canals of 52 mandibular molars were randomly distributed into 4 groups (n = 13) according to the different glide path techniques used before biomechanical preparation with Reciproc System (RS): KF/RS (sizes 10 and 15 K-files), NGP/RS (no glide path, only reciprocating system), PF/RS (sizes 13, 16, and 19 PathFile instruments), and NP (no preparation). Cone-beam computed tomography analysis was performed before and after instrumentation for apical third images acquisition. Apical transportation and its direction were evaluated by using the formula D = (X1 - X2) - (Y1 - Y2), and the centering ability was analyzed by the formula CC = (X1 - X2/Y1 - Y2 or Y1 - Y2/X1 - X2). The samples were submitted to histologic processing and analyzed under a digital microscope for debris quantification. The values were statistically analyzed (Kruskal-Wallis, the Dunn multiple comparisons test, P < .05). RESULTS: All groups had similar apical transportation values, with no significant difference among them (P > .05). Groups had a tendency toward transportation in the mesial direction. No technique had perfect centering ability (=1.0), with no significant difference among them. KF/RS had larger amount of debris, with statistically significant difference in comparison with NGP/RS (P > .05). CONCLUSIONS: The different glide path techniques promoted minimal apical transportation, and the reciprocating single-file system tested remained relatively centralized within the root canal. Also, the different techniques interfered in the cleaning effectiveness of the reciprocating system.

Correlation of fractal dimension with histomorphometry in maxillary sinus lifting using autogenous bone graft.

The aim of this study was to determine the pattern of bone remodeling after maxillary sinus lifting in humans by means of fractal dimension (FD) and histomorphometric analysis. Therefore, the correlation between FD and the histomorphometric findings was evaluated. Sixteen patients with posterior edentulous maxilla were enrolled in this study. Maxillary sinus lifting was performed using autogenous bone grafted from the mandibular retromolar area. Three direct digital panoramic radiographs were obtained: before surgery (Group 1), immediately postoperatively (Group 2) and after 6 months of healing (Group 3) for FD analysis. Biopsies were taken after 6 months, processed and submitted to histological and histomorphometric analysis. Data were analyzed by Shapiro-Wilk test and ANOVA test followed by a Tukey test (a = 0.05). The bone volume fraction of newly trabecular bone (TB) and medullary area (MA) was measured as 62.75% ± 17.16% and 37.25 ± 17.16%, respectively. Significant difference in FD analysis was measured between Group 1 and Group 3. No significant difference was found in the correlation between FD and histomorphometric analysis for TB and MA (p = 0.84). In conclusion, all performed analyses were effective in assessing the bone-remodeling pattern in the maxillary sinus, offering complementary information about healing and predictable outcomes. There were no correlations between FD and histomorphometric analysis.

Tissue response to polyanionic collagen: elastin matrices implanted in rat calvaria.

The tissue response to polyanionic collagen matrices, prepared from bovine pericardium and implanted subperiosteally in rat calvaria, was studied. The materials were implanted in 72 male rats (Rattus norvegicus, albinus, Holtzman), randomly divided into four groups: GI-MBP hydrolyzed for 24 h; GII-MBP hydrolyzed for 36 h; GIII-MBP hydrolyzed for 48 h; GIV-native MBP. The materials were explanted after 15, 30 and 60 days and analyzed by routine histological procedures. Except for group IV (native bovine pericardium), polyanionic collagen from groups GI, GII and GIII showed low inflammatory reaction associated with bone formation, partially or completely integrated to the cranial bone; group GIV was characterized by an intense inflammatory reaction with occasional dystrophic mineralization and with occasional bone formation at 60 days when there was a decrease in the inflammatory reaction. Thus, the MBP from groups I, II and III were biologically compatible, enhancing bone formation with a slight delay at 60 days in GII.

Histopathological features of dental pulp in teeth with different levels of chronic periodontitis severity.

Purpose. To evaluate the histopathological condition of the pulp in teeth with different levels of chronic periodontitis in humans. Methods. Twenty-five single-root nondecayed teeth were divided into three groups as follows: group 1, clinical attachment level (CAL) 3 to 4 mm and alveolar bone loss (BL) from 4 to 6 mm without reaching the tooth apex; group 2, CAL ≥ 5 mm and BL > 6 mm without reaching the tooth apex; group 3, CAL ≥ 5 mm and BL > 6 mm up to the tooth apex. Histological analyses were accomplished after laboratorial processing. Results. The mean of CAL was 3.2 ± 0.7 mm in group 1, 7.6 ± 2.0 mm in group 2, and 12.1 ± 2.8 mm in group 3, while for BL it was 4.8 ± 0.9 mm, 7.6 ± 2.2 mm, and 11.9 ± 2.1 mm, respectively. Histopathological data in the pulpal chambers were similar among the three groups showing normal aspects, and, the radicular pulps showed variable levels of reactive dentin, fibrosis, dystrophic mineralizations, atrophy, and mononuclear inflammatory infiltrate. Conclusions. Gradual progression of the chronic periodontitis led to changes in the histopathological aspects of the radicular pulp with progressive involvement.

Correlation of Fractal Dimension with Histomorphometry in Maxillary Sinus Lifting Using Autogenous Bone Graft

The aim of this study was to determine the pattern of bone remodeling after maxillary sinus lifting in humans by means of fractal dimension (FD) and histomorphometric analysis. Therefore, the correlation between FD and the histomorphometric findings was evaluated. Sixteen patients with posterior edentulous maxilla were enrolled in this study. Maxillary sinus lifting was performed using autogenous bone grafted from the mandibular retromolar area. Three direct digital panoramic radiographs were obtained: before surgery (Group 1), immediately postoperatively (Group 2) and after 6 months of healing (Group 3) for FD analysis. Biopsies were taken after 6 months, processed and submitted to histological and histomorphometric analysis. Data were analyzed by Shapiro-Wilk test and ANOVA test followed by a Tukey test (a=0.05). The bone volume fraction of newly trabecular bone (TB) and medullary area (MA) was measured as 62.75%±17.16% and 37.25±17.16%, respectively. Significant difference in FD analysis was measured between Group 1 and Group 3. No significant difference was found in the correlation between FD and histomorphometric analysis for TB and MA (p=0.84). In conclusion, all performed analyses were effective in assessing the bone-remodeling pattern in the maxillary sinus, offering complementary information about healing and predictable outcomes. There were no correlations between FD and histomorphometric analysis.

O objetivo deste estudo foi determinar o padrão de remodelação óssea após levantamento de seio maxilar in humanos por meio de analise de dimensão fractal (FD) e histomorfometria. Além disso, a correlação entre FD e histomorfometria foi avaliada. Dezesseis pacientes com edentulismo na região posterior da maxila foram relacionados para este estudo. Levantamento de seio maxilar foi realizado utilizando-se enxerto de osso autógeno coletado da região retro molar da mandíbula. Três radiografias panorâmicas digitais foram obtidas: antes da cirurgia (Grupo 1), imediatamente após o levantamento de seio (Grupo 2) e após 6 meses de cicatrização (Grupo 3) para analise de FD. Biopsias foram coletadas após 6 meses, processadas e submetidas para analise histológica e histomorfométrica. Os dados foram analisados utilizando-se o teste Shapiro-Wilk e ANOVA seguido pelo pós teste de Tukey (a=0.05). A fração de volume de ósseo neoformado para o osso trabecular (TB) e para a área medular (MA) foi mensurado como 65,75%±17,16% and 37,25±17,16%, respectivamente. Diferença significante na analise FD foi observada entre os grupos 1 e 3. Nenhuma diferença estatística foi encontrada para correlação entre FD e histomorfometria para TB e MA (p=0,84). Em conclusão, todas as análises realizadas foram efetivas em acessar o padrão de remodelação ósseo no seio maxilar, oferecendo informações complementares sobre cicatrização e previsibilidade de resultados. Não houve correlação entre FD e histomorfometria.

[Analysis of the tissue answer regarding two root canal sealers]. / Análise da resposta tecidual de dois cimentos endodônticos.

On the present study, two root canal sealers have been comparatively analysed, Sealapex® and Apexit®, in relation to its biological compatibility to subcutaneous tissue. For this analysis, twelve male rats weighing in average 250 g have been used, divided in three groups, according with its experimental time, 7, 21 and 45 days. Making part of the study, four incisions on the dorsal area of each rat have been made, where were implanted four polyetilene tubes, filled with the testing root canal sealers. After seven, twenty-one and forty-five days of the surgery, the animals have been sacrified and the tissues have been laboratory processed to obtain the histological cut coloured by hematoxilin-eosin, and subsequent quality analysis of the results. From this results, were verified that both sealers caused tissue's intense macrofagic activity, in the experimental time. Apexit caused a more agressive tissue reaction, in relation to the Sealapex, with also higher macrofagic activity. Sealapex showed better results in comparison to inflamatory intensitivity and tissue repair level.

Orthodontic movement of teeth with intraosseous defects: Histologic and histometric study in dogs.

The purpose of this study was to evaluate histologically, in dogs, the periodontal healing of 1-walled intraosseous defects in teeth that were subjected to orthodontic movement toward the defects. The defects were surgically created bilaterally at the mesial aspects of the maxillary second premolars and distal aspects of the mandibular second premolars of 4 mongrel dogs. One week after creating the defects, an orthodontic appliance was installed, and the teeth were randomly assigned to 1 of 2 treatment groups: those in the test group received a titanium-molybdenum alloy rectangular wire spring that performed a controlled tipping root movement, and those in the control group received a passive stainless steel wire. Active orthodontic movement of the test teeth lasted 2 months and was followed by a stabilization period of another 2 months, after which the animals were killed. Throughout the study, routine daily plaque control was performed on the dogs with a topical application of a 2% chlorhexidine gel. The results showed no difference between the groups, with some regularization of the defects and periodontal regeneration limited to the apical portion of the defects. Histometric analysis showed a significant difference in bone height; on average, it was 0.53 mm smaller in the test group. It was concluded that orthodontic movement does not interfere with the healing of 1-walled intraosseous defects, with the exception of the linear extent of new bone apposition.

Clinical, radiographic and histological evaluation of chronic periapical inflammatory lesions.

The aim of the present study was to comparatively evaluate the clinical, radiographic and histological aspects of chronic inflammatory periapical lesions. One hundred and sixty-four lesions of human teeth, independent of age, race and sex, were evaluated by clinical, radiographic and histological analyses conducted after surgical endodontic treatment. Our results showed that there was uniformity in the interference factors on the evolution of periapical healing such as the apical biofilm and/or endogenous (cholesterol crystals) or exogenous (extruded endodontic materials that are indigestible or of difficult digestion) foreign bodies and that some cysts are reversible with endodontic treatment. We conclude that it is difficult for the clinician to adjust parameters defining a diagnosis of chronic inflammatory periapical lesions.

Apical and periapical tissues responses afterroot canal obturation with two calcium hydroxid based sealers in dogs teeth / Reações teciduais apicais e periapicais quandoda obturação de canais radiculares de cães por dois cimentos contendo hidróxido de cálcio

Introduction: At the ending of endodontic treatment, is very important that the choice of root canal’s sealer will be done by biological compatibility criterial, which could promote less inflammation, turning quicker and more effective the healing process. Objective and material and methods: The aim of this study was to evaluate the apical and periapical tissues reactions in dog’s teeth, after pulpectomy and root canal’s cleaning and shaping, which limit was the fisiological barrier of delta apical, and filling with gutta-percha and two calcium hydroxide based endodontics sealers, Sealapex® and Apexit®, by those hystopatological events in observation periods of 7, 21 and 45 days, making a comparison of inflammatory reactions and reparacional evolution that both materials promoted. Past all periods, the dogs were killed and histological cuts of teeth were obtained. Results: Through qualitative-quantitative analysis, Sealapex showed inflammatory level among mild and moderate in all periods, having a great improvement in healing process at 45 days. There was a biggest dispersion of Apexit in periapical tissue, which caused an intense macrophage activity, raising inflammatory level in last period. Conclusion: Regardless of the sealer used, there were observed necrosis in a few of delta apical’s ramifications, being mostly in tooth filling by Apexit. In both ways, Sealapex showed best results than Apexit, about increased inflammatory reaction and healing process.

Introdução: No término do tratamento endodôntico é imprescindível que a escolha dos componentes da obturação seja feita com critério em relação à compatibilidade biológica, visando tornar o processo de reparação mais rápido e efetivo. Objetivo e material e métodos: Este estudo teve o propósito de analisar as reações teciduais apicais e periapicais em prémolares de cães, após pulpectomia e preparo químico-cirúrgico, cujo limite foi definido em nível do delta apical, e obturação com cones de gutapercha e dois cimentos contendo hidróxido de cálcio – Sealapex® e Apexit®. Foram analisados os eventos histopatológicos em períodos de 7, 21 e 45 dias, a fim de comparar os fenômenos de inflamação e de reparação. Decorridos os períodos de observação, os cães foram sacrificados, e as peças, processadas para análise histológica. Resultados: Empregandose análise quantitativa-qualitativa, verificou-se que o cimento Sealapex® promoveu inflamação entre discreta e moderada em todos os períodos, que evoluiu para reparação aos 45 dias. Houve maior dispersão do cimento Apexit® no tecido periapical, que promoveu intensa atividade macrofágica na área, ampliando os fenômenos de inflamação, mesmo aos 45 dias. Conclusão: Ambos os cimentos provocaram necrose em algumas ramificações do delta apical, ocorrendo porém em maior número nos dentes obturados com Apexit®. Da comparação entre o emprego dos dois cimentos, o Sealapex® foi o que apresentou melhor tolerância tecidual e, por conseqüência, evolução de reparação mais favorável.

Análise morfológica e morfométrica do tecido subcutâneo de ratos submetidos àação de pasta de hidróxido de cálcio e óleo de Ricinus communis / Morphological and morphometrical analysis of the subcutaneous tissue of rats submitted to the action of calcium hydroxide paste and Ricinus communis oil

Neste presente estudo foram comparadas duas composições de pastas medicamentosas para utilização intracanal: pasta de hidróxido de cálcio e óleo de Ricinus communis e pasta de hidróxido de cálcio e polietilenoglicol. Tubos de polietileno foram implantados no tecido subcutâneo de 9 ratos, sendo 2 escapulares e 2 pélvicos, totalizando 4 tubos por animal, cada par com uma das pastas. O grupo controle foi definido pela lateral do tubo. Após 7, 21 e 42 dias os animais foram sacrificados e os tecidos processados para obtenção dos cortes histológicos e posterior análise histopatológica. Os resultadosforam classificados quanto à severidade da reação inflamatória e quantificados em relação aos eventos presentesnas áreas pré-determinadas. Observou-se à análise morfológica, que ambas as pastas apresentaram índice de inflamação intenso aos 7 dias - pasta A (29,7) e pasta B (39,3), persistindo até aos 21 dias (pasta A – 27,1; pasta B – 27,9). Aos 42 dias a reação tecidual foi moderada (pasta A – 12,4; pasta B – 13,0). Comparando-se ao grupo controle, percebeu-se que este apresentava reação tecidual indo do moderado (14,2 aos 7 dias e 10,0 aos 21 dias) ao discreto (7,8 aos 42 dias).Quando submetidos à análise estatística (ANOVA – Tukey – p< .01) esses valores apresentaram diferença estatisticamente significante para todas as pastas e grupo controle. Concluiu-se que ambas as pastas apresentaram-se como irritantes ao tecido conjuntivo, permitindo colagenização progressiva da cápsula junto à abertura tubular. Porém, a pasta com óleo de Ricinus communis (Pasta A) apresentou potencial irritativo estatisticamente menor que a Pasta B.

Análise da resposta tecidual de dois cimentos endodônticos / Analysis of the tissue answer regarding two root canal sealers

No presente estudo foram analisados comparativamente dois cimentos endodônticos, Sealapex© e Apexit©, em relaçäo à sua compatibilidade biológica, em tecido subcutâneo. Para tanto, foram utilizados doze ratos, machos, pesando em média 250g, divididos em três grupos, de acordo com o tempo de observaçäo de 7, 21 e 45 dias. Como parte do estudo, foram feitas quatro incisöes na regiäo dorsal de cada rato, onde foram implantados quatro tubos de polietileno preenchidos com os cimentos em teste. Decorridos sete, vinte e um e quarenta e cinco dias da cirurgia, os animais foram sacrificados e os tecidos passaram por tramitaçäo laboratorial para obtençäo de cortes histológicos corados por hematoxilina-eosina, e posterior análise qualitativa dos resultados. Verificou-se que houve constante atividade macrofágica com o uso dos dois materiais, tendo o cimento Apexit© provocado uma reaçäo tecidual mais agressiva em relaçäo ao cimento Sealapex©, ao mesmo tempo em que, este último, mostrou melhores resultados quando analisadas a intensidade inflamatória provocada e a evoluçäo da reparaçäo tecidual

Clinical, radiographic and histological evaluation of chronic periapical inflammatory lesions

O objetivo deste estudo foi realizar uma avaliação comparativa entre os aspectos clínico-radiográficos e histopatológicos das lesões periapicais inflamatórias crônicas. Através deste, foram avaliadas 164 lesões inflamatórias crônicas periapicais provenientes de dentes de indivíduos, independendo de idade, raça e sexo. Foram encaminhados casos condizentes com periodontite apical crônica e processo cístico inflamatório avaliados através do exame clínico-radiográfico. Após procedimento cirúrgico, a análise histopatológica foi realizada. Os resultados clínico-laboratoriais foram submetidos à análise estatística. Os resultados mostraram que há constância de fatores de interferência na evolução do processo reparatório periapical representados com ênfase pelo biofilme microbiano apical e/ou por corpos estranhos tanto endógenos como os critais de colesterol quanto exógenos como os materiais endodônticos extravasados indigeríveis ou de difícil digestão; e que alguns processos císticos são passíveis de reversão com o tratamento endodôntico. Nesta pesquisa pode-se observar que é difícil para o clínico ajustar parâmetros definindo a hipótese diagnóstica das lesões periapicais inflamatórias crônicas.

Análise da ação antimicrobiana de medicações intracanal utilizadas em Endodontia / Analysis of antimicrobial action of root canal dressing used in Endodontics

Introdução - O objetivo do presente estudo foi determinar a ação antimicrobiana de duas substâncias - NDP e PRP - utilizadas como medicação intracanal em Endodontia, quando em contato como bactéria comumente encontrada na flora microbiana oral, o Staphylococcus aureus (ATCC 25923), em meios de cultura sólido e líquido. Materiais e Métodos - A infusão bacteriana foi preparada utilizando meio BHI, correspondente a 0,5 da escala McFarland. Para o meio sólido, foi realizado o experimento em duas camadas de meio de cultura sobre placa de Petri. Na base foram colocados 10ml de meio Müeller-Hinton e, após sua solidificação, uma outra camada, também de 10ml, preparada com infusão de bactéria diluída em 1 x 10 elevado a 6, meio BHI e 5ml de Müeller-Hinton dando a concentração final de 15 x 10 elevado a 5 UFC/ml. Feito isso, foram espalhados aleatoriamente na placa do tipo Petri, discos de papel filtro, previamente embebidos nas substâncias-teste, soro fisiológico, como controle negativo e ampicilina, como controle positivo. Para o teste em meio líquido, foram colocados em tubos 2ml de meio BHI, acrescidos de uma mistura de 5ml de infusão bacteriana e BHI, previamente preparada para uma concentração final de 5 x 10 elevado a 5 UFC/ml. Em cada tubo foi colocado apenas um disco de papel. As placas e os tubos foram incubados em estufa a 37°C por 24 horas. Resultados - Houve formação de halos de inibição quando do uso das medicações PRP e NDP. Conclusões - O PRP mostrou maiores halos de inibição, indicando maior potencial antimicrobiano. Em meio líquido houve crescimento bacteriano em todos os tubos

Efeito de pastas à base de hidróxido de cálcio sobre a polpa de molares de ratos, exposta experimentalmente: estudo histopatológico comparativo / The effect of calcium hydroxide pastes in pulpar capping of rat molars: comparative histologic study

Foram utilizados 120 primeiros molares superiores de 60 ratos, com o objetivo de avaliar a reaçäo da polpa sob a açäo de pastas à base de hidróxido de cálcio. Os animais foram distribuídos em 3 grupos de 10 ratos, divididos em 5 períodos de 4 animais de 3, 7, 15, 30 e 45 dias. Concluiu-se que: 1 - todas as pastas caracterizam-se como irritantes, persistindo no decorrer dos períodos evoluçäo por reparaçäo; 2 - houve melhor comportamento nos grupos 1 (hidróxido de cálcio + polietileno glicol 400) e iii (hidróxido de cálcio + polietileno glicol 400 + óxido de zinco) sobre o II (hidróxido de cálcio + polietileno glicol 400 + iodofórmio); 3 - todas as pastas, a partir do 7- dia, induziram à formaçäo de massas amorfas como mineralizadas, tendendo a barreira, apresentando variaçöes na qualidade e na quantidade, acompanhando o comportamento reacional

Avaliaçäo do potencial irritativo do hipoclorito de sódio a 0,5 por cento (Líquido de Dakin) no tratamento de canais radiculares em dentes de cäes / Evaluation of irritative potential induced by sodium hypochlorite 0,5 percent (Dakin solution) for root canal therapy of dogs teeth

Segundos e terceiros pré-molares de 4 cäes machos foram submetidos a biopulpectomia, preparo de canal, irrigaçäo e preenchimento com soluçäo de hipoclorito de sódio a 0,5 por cento (Líquido de Dakin), por períodos de 72 horas e 7 dias. Decorridos os períodos experimentais, os animais foram sacrificados e após os procedimentos laboratoriais de rotina, a análise histopatológica foi executada, demonstrando que a soluçäo apresentou ser de baixo potencial irritativo, näo interferindo na vitalidade dos tecidos pulpares remanescentes e da regiäo periapical

Eficiência de limpeza de soluçöes irrigadoras empregadas na biomecânica de canais radiculares (instrumentaçäo manual e combinaçäo manual/ultra-sônica) / Efficiency of cleanness of irrigating solutions used in the biomechanics of radicular canals (hand and hand/ultrasonic combination)

A eficiência de limpeza de algumas soluçöes irrigadoras sobre a parede dentinária do canal radicular nas técnicas convencional e combinada manual/ultra-sônica foi avaliada, utilizando-se 50 dentes humanos, pré-molares inferiores, jovens, recém-extraídos, que foram instrumentados e irrigados com água destilada, líquido de Dakin, soluçäo de Mílton, soda clorada/água oxigenada/soda clorada e EDTA, sendo após preparados para análise em M.E.V., permitindo concluir: 1) näo houve diferenças estatísticas entre as técnicas empregadas (p > 0,10); 2) a ordenaçäo entre as soluçöes irrigadoras auxiliares de menor índice de limpeza para maior foi 1§) EDTA; 2§) soda clorada/água oxigenada/soda clorada e soluçäo de Mílton; e 3§) líquido de Dakin e água destilada, näo havendo significância estatística entre 2§ e 3§ (p > 0,05), sendo destacada entre 1§ para 2§ (p > 0,005) e 3§ (p < 0,001); 3) a ordenaçäo entre os terços radiculares do menor índice de resíduo para o maior foi : 1§) cervical; 2§) médio; e 3§) apical. Näo havendo significância estatística entre 1§ e 2§ (p > 0,05), sendo destacada entre 1§ e 2§ para 3§ (p < 0,01 e p < 0,05, respectivamente)

Análise histopatológica comparativa em polpa de dentes de cäes, após pulpotomia e utilizaçäo de pastas a base de hidróxido de cálcio em diferentes veículos / Histopathologic comparative analysis in dogs'vital teeth, after pulpotomy with calcium hydroxide pastes in different vehicles

O objetivo desta pesquisa foi avaliar comparativamente, mediante exame histopatológico, a reaçäo do tecido pulpar de dentes permanentes jovens de cäes, após pulpotomia e utilizaçäo de diferentes pastas a base de hidróxido de cálcio: grupo I - hidróxido de cálcio (0,5g) + polietileno glicol 400 (0,3ml); grupo II - hidróxido de cálcio (0,5g) + óxido de zinco (0,25g) + polietileno glicol 400 (0,3ml); grupo III - hidróxido de cálcio (0,5g) + carboximetilcelulose 1,66 por cento (0,5ml); grupo IV - hidróxido de cálcio (0,5g) + óxido de zinco (0,25g) + carboximetilcelulose 1,66 por cento (0,5ml). Com base nos resultados obtidos, pudemos concluir que: 1) as pastas avaliadas apresentaram boa tolerância tecidual, possibilitando evoluçäo reparativa, nos períodos de análise de 45, 90 e 150 dias; 2) em todos os grupos ocorreu formaçäo de barreira mineralizada completa, desenvolvendo-se em quantidade e qualidade, desde a condiçäo de massa amorfa, contendo resíduos diversos e grupamentos pulpares, até esboços de canalículos dentinários e tendência à ortodentina, no decorrer dos períodos, com melhores resultados no grupo II, seguido dos grupos I, IV e III