Experimental Medications for Using in Endodontics: Cytotoxicity, Genotoxicity and Mutagenesis Analysis / Medicamentos Experimentais para Uso em Endodontia: Análise de Citotoxicidade, Genotoxicidade E Mutagênese

The objective was to evaluate the cytotoxic, genotoxic and mutagenic properties of two experimental medication in Endodontics. For cytotoxic evaluation, fibroblast and osteoblast cells (1x104 cells/well) were plated and divided into groups conforming to the product added in culture medium: EM1 - 20 µL of experimental medication 1 (EM1); EM2 - 20 µL of experimental medication 2 (EM2); VE - 20 µL of vehicle used in medications; C - without product. The MTT assay was performed at 24, 48 e 72 hours for cytotoxic analysis. For genotoxic and mutagenic evaluation, 42 male rats were used. After 1 and 7 days of tubes containing EM1 or EM2, or empty (NC) were subcutaneously implanted, and after 1 day, a single dose of cyclophosphamide (CY) to be applied, the bone marrow was collected and submitted to comet and micronuclei assay. The significance level of 5% was considered for all statistical analysis. The viability of fibroblasts was <70% to both medications at 24h, and EM1 at 72h; at 72h, the proliferation cells was observed in EM2 (>100%). Both medications were non-cytotoxic to osteoblasts, and the EM2 stimulate the cell proliferation at 72h. The damage frequency of CY was statistically similar to EM1 and different to EM2 (p<0.05). The number of micronuclei was insignificant to EM1 and EM2 and no difference to group NC (p>0.05). Despite the absence of mutagenesis and non-cytotoxicity to osteoblasts, the EM1 was cytotoxic and genotoxic to fibroblasts. The EM2 was non-genotoxic, non-cytotoxic and nonmutagenic. (AU)

O objetivo foi avaliar as propriedades citotóxicas, genotóxicas e mutagênicas de dois medicamentos experimentais em Endodontia. Para avaliação citotóxica, células fibroblásticas e osteoblásticas (1x104 células/poço) foram plaqueadas e divididas em grupos de acordo com o produto adicionado no meio de cultura: EM1 - 20 µL da medicação experimental 1 (EM1); EM2 - 20 µL da medicação experimental 2 (EM2); VE - 20 µL de veículo utilizado em medicamentos; C ­ sem produto. O ensaio MTT foi realizado aos 24, 48 e 72 horas para análise citotóxica. Para avaliação genotóxica e mutagênica foram utilizados 42 ratos machos. Após 1 e 7 dias foram implantados por via subcutânea tubos contendo EM1 ou EM2, ou vazios (NC), e após 1 dia, foi aplicada dose única de ciclofosfamida (CY), a medula óssea foi coletada e submetida ao ensaio de cometa e micronúcleos. O nível de significância de 5% foi considerado para todas as análises estatísticas. A viabilidade dos fibroblastos foi <70% para ambas as medicações às 24h e ao EM1 às 72h; às 72h, a proliferação de células foi observada em EM2 (>100%). Ambas as medicações foram não citotóxicas para os osteoblastos, e o EM2 estimulou a proliferação celular às 72h. A frequência de dano do CY foi estatisticamente semelhante ao EM1 e diferente do EM2 (p<0,05). O número de micronúcleos foi insignificante para EM1 e EM2 e não houve diferença para o grupo NC (p>0,05). Apesar da ausência de mutagênese e não citotoxicidade para osteoblastos, o EM1 foi citotóxico e genotóxico para fibroblastos. O EM2 era não genotóxico, não citotóxico e não mutagênico. (AU)

Biomechanical analysis of narrow dental implants for maxillary anterior rehabilitation / Análise biomecânica de implantes de diâmetro reduzido para reabilitação da região anterior da maxila

Introdução: O conhecimento da biomecânica de implantes de diâmetro reduzido indica dimensões seguras para uso clínico. Objetivo: O objetivo do presente estudo foi comparar biomecanicamente implantes de diâmetro regular e reduzido para suporte de próteses implantossuportadas unitárias na região anterior da maxila por meio de análise de elementos finitos 3D (3D-FEA). Material e método: Quatro modelos 3D-FEA foram desenvolvidos a partir de recomposição de tomografia computadorizada e dados da literatura: um bloco ósseo na região incisiva lateral superior direita com implante e coroa. M1: 3,75 x 13 mm, M2: 3,75 x 8,5 mm, M3: 2,9 x 13 mm e M4: 2,9 x 8,5 mm. Foi aplicada carga de 178 N nos ângulos 0, 30 e 60 graus em relação ao longo eixo do implante. Foram avaliados mapas de tensão de Von Mises, tensão principal máxima e microdeformação. Resultado: M3 e M4 apresentaram maiores valores de tensão e microdeformação que M1 e M2, principalmente quando foram aplicadas forças inclinadas. Porém, M3 apresentou comportamento biomecânico melhor do que M4. Conclusão: Pode-se concluir que reduzir o diâmetro dos implantes pode prejudicar a biomecânica durante a aplicação de forças, mas a distribuição e intensidade das tensões, bem como os valores de microdeformação podem ser melhorados se o comprimento do implante for aumentado

Introduction: Narrow diameter implants biomechanics knowledge indicates safe dimensions for clinical use. Objective: Purpose of the present study was biomechanically to compare regular and narrow diameter implants to support single implant-supported prosthesis in the anterior region of the maxilla by 3D finite element analysis (3D-FEA). Material and method: Four 3D-FEA models were developed form CT scan recompositing and literature data: a bone block in the right upper lateral incisive region with implant and crown. M1: 3.75 x 13 mm, M2: 3.75 x 8.5 mm, M3: 2.9 x 13 mm and M4: 2.9 x 8.5 mm. It was applied load was of 178 N at 0, 30 and 60 degrees in relation to implant long axis. Von Mises stress, maximum principal stress and microdeformation maps were evaluated. Result: M3 and M4 did show higher tension and higher microdeformation values than M1 and M2, especially when inclined forces were applied. However, M3 presented enhanced biomechanical behavior than M4. Conclusion: It can be concluded that reduce the diameter of the implants can disadvantage to the biomechanics during the application of forces, but the distribution and intensity of the stresses, as well as the micro deformation values can be improved if the length of the implant is increased

Glass ionomer heated or not to identify bone defect created in rat calvaria / Ionômero de vidro aquecido ou não para identificação de defeitos ósseos criados em calvárias de ratos

Introduction: Some experimental models have been used to evaluate the use of biomaterials in bone regeneration. Among them are the critical size defects (CSD) created in rat calvaria. An experimental model has been described in the literature, in which "L" markings are performed on the margins of the bone defects in order to assist in the precise identification of these defects during laboratory processing and analysis of the results. In the proposed model, the "L" markings are filled with amalgam. Objective: The purpose of the present study was to evaluate the amalgam replacement of an experimental bony defect model in rat calvaria by heated or unheated glass ionomer. Material and method: 24 rats were used. A 5 mm CSD was created at each animal calvaria. Two "L" shaped markings were made 2 mm from the margins of the bone defect, filled with amalgam (Group AM), heated glass ionomer cement (Group GIh) or not (Group GI). The animals were euthanized 15 days postoperatively. The areas of the surgical defect and the L-shaped marking were histomorphometrically analyzed and the data were analyzed statistically (p <0.05). Result: There were no significant clinical, histological or methodological differences among the experimental groups. Conclusion: It can be concluded that GI can replace AM in the proposed experimental model and GI heating did not promote additional benefits.

Introdução: Alguns modelos experimentais têm sido usados para avaliar o uso de biomateriais na regeneração óssea. Entre eles estão os defeitos de tamanho crítico (DTC) criados em calvárias de ratos. Um modelo experimental foi descrito na literatura onde marcações em L são realizadas nas margens do defeito ósseo para auxiliar na identificação precisa desses defeitos durante o processamento laboratorial e análise dos resultados. No modelo experimental proposto, as marcações em "L" são preenchidas com amálgama. Objetivo: Avaliar a substituição do amálgama por ionômero de vidro aquecido ou não em um modelo experimental para identificação de defeito ósseo criado em calvária de ratos. Material e método: Foram utilizados 24 ratos. Um DTC de 5 mm de diâmetro foi criado na calvária de cada animal. Duas marcações em "L" foram realizadas a 2 mm das margens do defeito ósseo, preenchidas com amálgama (Grupo AM), ionômero de vidro aquecido (Grupo CIVaq) ou não (Grupo CIV). Os animais foram eutanasiados aos 15 dias pós-operatórios. A área do defeito cirúrgico e das marcações em "L" foram histomorfometricamente avaliadas e os dados estatisticamente analisados (p<0,05). Resultado: Não houve diferença estatisticamente significativa entre os grupos experimentais para as análises metodológicas, clínicas ou histomorfométrica realizadas. Conclusão: Dentro dos limites deste estudo, pode-se concluir que CIV pode substituir o AM no modelo experimental proposto e o aquecimento do CIV não promoveu benefícios adicionais.

Influence of anti-allergic drugs used systemically on the process of root resorption during delayed tooth replantation: A study in rats.

BACKGROUND/AIM: Anti-allergic drugs can inhibit the hard tissue resorption process, and due to similarities between root resorption and bone mechanisms, it can be inferred that these drugs may also control root resorption. The aim of this study was to analyze the effects of anti-allergic drugs used systemically on the process of root resorption following delayed tooth replantation. MATERIALS AND METHODS: Thirty-two maxillary right incisors of rats were extracted and subsequently replanted. Rats were divided into four groups according to the anti-allergic drug administered: the rats in groups DEX, Q, and MO were treated systemically with dexamethasone phosphate, quercetin, and montelukast, respectively, and no systemic medication was administered to rats in group C. After 60 days, the animals were euthanized, and the specimens were processed for histomorphometric and immunohistochemical analyses. Statistical significance was set at P < .05. RESULTS: There were no significant differences between the groups in terms of inflammatory resorption, replacement resorption, or presence of tartrate-resistant acid phosphatase. In terms of events occurring in the periodontal ligament space, there was a difference between groups Q and MO due to the presence of dental ankylosis and inflammatory connective tissue (P < .05). A difference in inflammatory cells was also observed through CD45 immunolabeling between the DEX and Q groups when compared to the C group (P < .05). CONCLUSION: The systemic administration of anti-allergic drugs did not have an effect on the process of root resorption following delayed tooth replantation.

Treatment of experimental periodontitis with chlorhexidine as adjuvant to scaling and root planing.

OBJECTIVES: To assess whether subgingival irrigation with 0.12 % or 0.2 % chlorhexidine (CHX) immediately after scaling and root planing (SRP) enhances periodontal tissue repair compared to irrigation with saline solution (control). MATERIALS AND METHODS: Periodontitis was ligature-induced in rat molars for 7 days. Animals were distributed into three groups: 1) SRP group, SRP and irrigation with 0.9 % saline (n = 30); 2) SRP + 0.12 % CHX group, SRP and irrigation with 0.12 % CHX (n = 30); 3) SRP + 0.2 % CHX group, SRP and irrigation with 0.2 % CHX (n = 30). Animals were killed at 7, 15, and 30 days after treatment. Furcation region was histometrically analyzed to determine the bone area. Immunohistochemical reactions were performed for receptor activator of nuclear factor-kB ligand (RANKL), osteoprotegerin (OPG) and tartrate-resistant acid phosphatase (TRAP). RESULTS: Both chlorhexidine groups presented less inflammation and improved tissue repair along the entire experiment when compared with the SRP group. In the histometric analysis at 7, 15 and 30 days, SRP group (4.58 ±â€¯2.51 mm2, 4.21 ±â€¯1.25 mm2, 3.49 ±â€¯1.48 mm2), showed statistically less bone area than groups SRP + 0.12 % CHX (1.86 ±â€¯1.11 mm2; 0.79 ±â€¯0.27 mm2; 0.34 ±â€¯0.14 mm2) and SRP + 0.2 % CHX (1.14 ±â€¯0.51 mm2; 0.98 ±â€¯0.40 mm2; 0.41 ±â€¯0.21 mm2). Both chlorhexidine concentrations modulated the expression of TRAP, RANKL and OPG. CONCLUSIONS: Subgingival irrigation with chlorhexidine contributed for a quicker shift from a proinflammatory destructive profile to healing of periodontal tissues.

Influence of low-level laser therapy on the healing of human bone maxillofacial defects: A systematic review.

PURPOSE: This systematic review evaluates the effectiveness of low-level laser therapy (LLLT) to enhance maxillofacial area bone repair. METHODS: A comprehensive search of studies published up to February 2017 and listed in PubMed/MEDLINE, Scopus, and Cochrane Library databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. RESULTS: The 15 selected studies evaluated a total of 374 patients (mean age, 28.5years) who were treated with LLLT. Gallium-arsenide (GaAs) and gallium aluminium arsenide (GaAlAs) were the most commonly used devices, and LLLT parameters varied greatly. Wavelengths varied from 500 to 1000nm. Tooth extraction, distraction osteogenesis, maxillary expansion, periodontal defects, orthodontic movement and maxillary cystic defects were evaluated. From the 15 selected studies, six evaluated bone repair (primary outcomes). Of these, four studies showed improvement in bone formation after using LLLT, two demonstrated improved results for only one follow up period, and one showed no additional benefits. The other 9 studies evaluated secondary parameters related to healing (secondary outcomes) in the maxillofacial area after applying LLLT, including anti-inflammatory, analgesic, and healing accelerator effects, and quality of life related to oral health. There were no adverse or negative effects of LLLT reported. CONCLUSION: Within the limitation of this review, a possible improvement in bone density can be found when LLLT is applied postoperatively in maxillofacial bony defects. LLLT also seems to promote anti-inflammatory and analgesic effects and accelerate healing, as well as enhance quality of life related to oral health. However, LLLT use protocols need to be standardized before more specific conclusions can be drawn about this subject.

Reparo ósseo de defeitos de tamanho crítico tratados com aspirado de medula óssea associado ou não a terapia com laser em baixa intensidade: estudo imunoistoquímico em calvárias de ratos / Bone healing in critical-size defects treated with bone marrow aspirate combined or not with low-level laser therapy: an immunohistochemical study in rat calvaria

Este estudo imunoistoquímico avaliou a influência do aspirado de medula óssea (AMO) associado ou não à terapia com laser em baixa intensidade (LLLT) no processo de reparo de defeitos de tamanho crítico (DTC), criados cirurgicamente em calvárias de ratos. 64 ratos foram aleatoriamente distribuídos em 4 grupos: C (controle), AMO, LLLT e AMO/LLLT. Um DTC de 5 mm de diâmetro foi criado na calvária de cada animal. No Grupo C, o defeito foi preenchido com coágulo sanguíneo somente. No Grupo AMO, o defeito preenchido com AMO. Nos grupos LLLT e AMO/LLLT, o defeito recebeu irradiação com laser (InGaAlP laser), foi preenchido com coágulo sanguíneo ou AMO, respectivamente, e irradiado novamente. Os animais foram submetidos à eutanásia aos 15 e 30 dias pós-operatórios. Foram realizadas reações imunoistoquímicas para detecção do fator de crescimento endotelial vascular (VEGF), antígeno nuclear de proliferação celular (PCNA), fator de transcrição relacionado à Runt (Runx2), proteína óssea morfogenética-2 (BMP-2), osteopontina (OPN) e osteocalcina (OCN). Um método semi-quantitativo foi usado para avaliar a imunomarcação para VEGF. As células PCNA-positivas, Runx2-positivas, BMP-2-positivas, OPN-positivas e OCN-positivas foram quantificadas. Os dados obtidos foram analisados estatisticamente. Aos 15 dias pós-operatórios, o Grupo LLLT apresentou números de células OPN-positivas e OCN-positivas significativamente maiores que o Grupo C; o Grupo AMO apresentou números de células PCNA-positivas, Runx2-positivas, BMP-2-positivas e OPN-positivas significativamente maiores do que os grupos C e LLLT, além de número de células OCN-positivas significativamente maior que o controle; o Grupo AMO/LLLT apresentou imunomarcação para VEGF e números de células Runx2-positivas, OPN-positivas e OCN-positivas significativamente maiores que o Grupo C. Aos 30 dias pós-operatórios, o Grupo LLLT apresentou imunomarcação para VEGF e números de células OPN-positivas e OCN-positivas significativamente...

This immunohistochemical study evaluated the influence of bone marrow aspirate (BMA) combined or not with low-level laser therapy (LLLT) on bone healing in surgically created critical-size defects (CSDs) in rat calvaria. 64 rats were randomly divided into 4 groups: C (control), BMA, LLLT and BMA/LLLT. A 5 mm diameter CSD was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group BMA, the defect was filled with BMA. In groups LLLT and BMA/LLLT, the defect received laser irradiation (InGaAlP laser), was filled with blood clot or BMA respectively, and irradiated again. Animals were euthanized at either 15 or 30 days postoperative. Vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), runt-related transcription factor-2 (Runx2), bone morphogenetic protein-2 (BMP-2), osteocalcin (OCN) and osteopontin (OPN) immunohistochemical staining were performed. A semi-quantitative method was used to evaluate VEGF immunolabeling. PCNA-positive, Runx2-positive, BMP-2-positive, OPN-positive and OCN-positive cells were quantified. Data were statistically analyzed. At 15 days postoperative, Group LLLT presented a significantly higher number of OPN-positive and OCN-positive cells than Group C; Group BMA presented a significantly higher number of PCNA-positive, Runx2-positive, BMP-2-positive and OPN-positive cells than groups C and LLLT, and a significantly higher number of OCN-positive cells than control; Group BMA/LLLT presented significantly higher VEGF immunolabeling and number of Runx2-positive, OPN-positive and OCN-positive cells than Group C. At 30 days postoperative, Group LLLT presented significantly higher VEGF immunolabeling and number of OPN-positive and OCN-positive cells than Group C; Group BMA presented a higher number of Runx2-positive, BMP-2-positive and OCN-positive cells than Group C; Group BMA/LLLT presented a significantly higher number of PCNA-positive, BMP-2-positive...

Reparo ósseo de defeitos de tamanho crítico tratados com aspirado de medula óssea associado ou não a terapia com laser em baixa intensidade: estudo imunoistoquímico em calvárias de ratos / Bone healing in critical-size defects treated with bone marrow aspirate combined or not with low-level laser therapy: an immunohistochemical study in rat calvaria

Este estudo imunoistoquímico avaliou a influência do aspirado de medula óssea (AMO) associado ou não à terapia com laser em baixa intensidade (LLLT) no processo de reparo de defeitos de tamanho crítico (DTC), criados cirurgicamente em calvárias de ratos. 64 ratos foram aleatoriamente distribuídos em 4 grupos: C (controle), AMO, LLLT e AMO/LLLT. Um DTC de 5 mm de diâmetro foi criado na calvária de cada animal. No Grupo C, o defeito foi preenchido com coágulo sanguíneo somente. No Grupo AMO, o defeito preenchido com AMO. Nos grupos LLLT e AMO/LLLT, o defeito recebeu irradiação com laser (InGaAlP laser), foi preenchido com coágulo sanguíneo ou AMO, respectivamente, e irradiado novamente. Os animais foram submetidos à eutanásia aos 15 e 30 dias pós-operatórios. Foram realizadas reações imunoistoquímicas para detecção do fator de crescimento endotelial vascular (VEGF), antígeno nuclear de proliferação celular (PCNA), fator de transcrição relacionado à Runt (Runx2), proteína óssea morfogenética-2 (BMP-2), osteopontina (OPN) e osteocalcina (OCN). Um método semi-quantitativo foi usado para avaliar a imunomarcação para VEGF. As células PCNA-positivas, Runx2-positivas, BMP-2-positivas, OPN-positivas e OCN-positivas foram quantificadas. Os dados obtidos foram analisados estatisticamente. Aos 15 dias pós-operatórios, o Grupo LLLT apresentou números de células OPN-positivas e OCN-positivas significativamente maiores que o Grupo C; o Grupo AMO apresentou números de células PCNA-positivas, Runx2-positivas, BMP-2-positivas e OPN-positivas significativamente maiores do que os grupos C e LLLT, além de número de células OCN-positivas significativamente maior que o controle; o Grupo AMO/LLLT apresentou imunomarcação para VEGF e números de células Runx2-positivas, OPN-positivas e OCN-positivas significativamente maiores que o Grupo C. Aos 30 dias pós-operatórios, o Grupo LLLT apresentou imunomarcação para VEGF e números de células OPN-positivas e OCN-positivas significativamente...

This immunohistochemical study evaluated the influence of bone marrow aspirate (BMA) combined or not with low-level laser therapy (LLLT) on bone healing in surgically created critical-size defects (CSDs) in rat calvaria. 64 rats were randomly divided into 4 groups: C (control), BMA, LLLT and BMA/LLLT. A 5 mm diameter CSD was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group BMA, the defect was filled with BMA. In groups LLLT and BMA/LLLT, the defect received laser irradiation (InGaAlP laser), was filled with blood clot or BMA respectively, and irradiated again. Animals were euthanized at either 15 or 30 days postoperative. Vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), runt-related transcription factor-2 (Runx2), bone morphogenetic protein-2 (BMP-2), osteocalcin (OCN) and osteopontin (OPN) immunohistochemical staining were performed. A semi-quantitative method was used to evaluate VEGF immunolabeling. PCNA-positive, Runx2-positive, BMP-2-positive, OPN-positive and OCN-positive cells were quantified. Data were statistically analyzed. At 15 days postoperative, Group LLLT presented a significantly higher number of OPN-positive and OCN-positive cells than Group C; Group BMA presented a significantly higher number of PCNA-positive, Runx2-positive, BMP-2-positive and OPN-positive cells than groups C and LLLT, and a significantly higher number of OCN-positive cells than control; Group BMA/LLLT presented significantly higher VEGF immunolabeling and number of Runx2-positive, OPN-positive and OCN-positive cells than Group C. At 30 days postoperative, Group LLLT presented significantly higher VEGF immunolabeling and number of OPN-positive and OCN-positive cells than Group C; Group BMA presented a higher number of Runx2-positive, BMP-2-positive and OCN-positive cells than Group C; Group BMA/LLLT presented a significantly higher number of PCNA-positive, BMP-2-positive...

Abordagens periodontais na promoção da harmonia do sorriso / Periodontal approaches in promotion of harmony smile

Várias abordagens terapêuticas têm sido propostas com o objetivo de alcançar uma estética favorável e harmônica do sorriso. O presente estudo relata um caso clínico em que foi realizada gengivoplastia na região dos dentes anteriores superiores associada à osteotomia na região dos dentes posteriores superiores e remoção do freio labial superior, para promoção da harmonia do sorriso, por meio da diminuição do sorriso gengival e adequação do corredor bucal. Os procedimentos de osteoplastia, gengivoplastia e frenectomia foram planejados e realizados em uma única sessão. Também foi realizada a remoção cirúrgica do freio labial superior que se apresentava fibroso e com baixa inserção, e dos terceiros molares superiores direito e esquerdo, que se apresentavam semi-inclusos, para evitar complicações pós-operatórias. Consultas de acompanhamento foram realizadas aos sete, 15, 30 e 180 dias do pós- operatório. Aos sete dias, o tecido gengival encontrava-se em processo inicial de cicatrização. Aos 15 dias, o tecido gengival encontrava-se nos períodos finais da cicatrização, já apresentando as características normais. Aos 30 dias, foi observada completa cicatrização dos tecidos gengivais, sem exposição clínica das superfícies radiculares. Após 180 dias, os tecidos permaneceram saudáveis, demonstrando o sucesso do tratamento realizado. A paciente demonstrou completa satisfação com os resultados obtidos. Pôde-se concluir que, quando bem indicadas, a gengivoplastia e a osteotomia são abordagens terapêuticas promissoras para promoção da harmonia do sorriso.

Several therapeutic approaches have been proposed in order to achieve an esthetically pleasing and harmony smile. The present study reports a case in which gingivectomy was performed in the region of the upper anterior teeth combined with osteotomy in the region of the upper posterior teeth and removal of the superior labial frenum to promote harmony smile by decreasing the gummy smile and adequacy of buccal corridor. Osteoplasty gingivoplasty, and frenectomy procedures were planned and performed in a single session. The extraction of the maxillary third molars was also performed in order to avoid postoperative complications. Follow-up visits were performed at 7, 15, 30 and 180 days postoperatively. At 7 days, the gingival tissue was in the initial process of healing, demonstrating inflammation still in evidence. At 15 days, the gingival tissue was found in the final healing process, showing characteristics of normal health gum. At 30 days, there was complete healing of gingival tissues without clinical exposure of the root surfaces. After 180 days, tissues remained in healthy, demonstrating the success of the treatment. Patient showed complete satisfaction with the results. It can be concluded that, when properly indicated, the combination of gingivectomy, osteotomy and frenectomy procedures are promising therapeutic approaches for promoting harmony smile.

Treatment of experimental periodontitis in rats using repeated adjunctive antimicrobial photodynamic therapy.

The aim of this study was to histologically and histometrically evaluate the influence of repeated adjunctive antimicrobial photodynamic therapy (aPDT) on bone loss (BL) in furcation areas in rats. Periodontitis was induced by placing a ligature around the mandibular molar in 75 rats. The animals were divided into five groups: the SS group was treated with saline solution (SS); the SRP group received scaling and root planing (SRP); the aPDT1 group received SRP as well as toluidine blue (TBO) and low-level laser therapy (LLLT; InGaAlP, 660 nm; 4.94 J/cm(2)/point) postoperatively at 0 h; the aPDT2 group received SRP as well as TBO and LLLT postoperatively at 0, 24, 28, and 72 h; and the aPDT3 group received SRP, TBO, and LLLT postoperatively at 0, 48, 96, and 144 h. The area of BL in the furcation region of the molar was histometrically analyzed. Data were analyzed statistically (P < 0.05). Animals treated with a single episode of aPDT showed less BL at days 7 and 30 than those who received only SRP treatment. No significant differences were found among the aPDT groups (P > 0.05). Repeated aPDT did not improve BL reduction when compared to a single episode of aPDT.

A proporção plasma rico em plaquetas/enxerto ósseo autógeno pode influenciar o reparo ósseo de defeitos de tamanho crítico: um estudo radiográfico em calvária de ratos / The proportion platelet-rich plasma/particulate autogenous bone graft may influencebone healing in criticalsize defects: a radiographic study in rat calvaria

Introdução: Tem sido sugerido que enxertos ósseos associados ao Plasma Rico em Plaquetas (PRP) cicatrizam com maior densidade que os enxertos sem PRP. Contudo, esse resultado parece depender da proporção PRP/enxerto ósseo utilizada. Objetivo: O propósito deste estudo foi avaliar, radiograficamente, a influência da proporção PRP/enxerto de Osso Autógeno (OA) no reparo ósseo de defeitos de tamanho crítico (DTCs) criados cirurgicamente em calvárias de ratos. Material e método: Cinquenta ratos foram divididos em cinco grupos: C, OA, OA/PRP-50, OA/PRP-100 e OA/PRP-150. Um DTC de 5 mm de diâmetro foi criado na calvária de cada animal. No Grupo C, o defeito cirúrgico foi preenchido somente com coágulo sanguíneo. No Grupo OA, o defeito foi preenchido com enxerto de OA particulado. Nos grupos OA/PRP-50, OA/PRP-100 e OA/PRP-150, o defeito foi preenchido com enxerto de OA particulado associado a 50, 100 ou 150 µL de PRP, respectivamente. Os animais foram eutanasiados aos 30 dias pós-operatórios. Imagens radiográficas padronizadas das calvárias foram obtidas com o sistema Digora (Soredex, Finlândia). As imagens foram avaliadas por três examinadores por meio de escores, que indicaram o percentual de radiopacidade dos defeitos. Os escores obtidos foram submetidos ao Teste de Kruskal-Wallis (p < 0,05). Resultado: O Grupo C apresentou radiopacidade significativamente menor que os grupos OA, OA/PRP-50, OA/PRP-100 e OA/PRP-150 (p < 0,05). O Grupo OA/PRP-50 apresentou radiopacidade significativamente maior que os grupos OA/PRP-100 e OA (p < 0,05). Conclusão: Dentro dos limites deste estudo, pode-se concluir que a proporção PRP/enxerto de OA influencia a cicatrização de DTCs criados em calvárias de ratos.

Introduction: It has been suggested that bone grafts combined with platelet rich plasma (PRP) present greater density than bone grafts without PRP after healing process. However, this result may depend on proportion PRP/autogenous bone (AB) graft used. Objective: The purpose of this study was to analyze radiographically the influence of the proportion PRP/particulate autogenous bone (AB) graft on bone healing in surgically created criticalsize defects (CSD) in rat calvaria. Material and method: 50 rats were divided into 5 groups: C, AB, AB/PRP-50, AB/PRP-100 and AB/PRP-150. A 5 mm diameter CSD was created in the calvarium of each animal. In Group C the defect was filled by blood clot only. In Group AB the defect was filled with 0.01 mL of AB graft. In groups AB/ RP-50, AB/PRP-100 and AB/PRP-150 the defects were filled with 0.01 mL of AB graft combined with 50, 100 and 150 µL of PRP, respectively. All animals were euthanized at 30 days post-operative. Standardized radiographic images of the rat calvaria were obtained using Digora System (Soredex, Finland). The images were evaluated by three examiners using scores that indicated the percentage of radiopacity of the defect. The obtained data were subjected to statistical analysis (Kruskal-Wallis test, p <0.05). Result: Group C presented radiopacity significantly lower than groups AB, AB/PRP-50, AB/PRP-100 and AB/PRP-150. Group AB/PRP-50 showed radiopacity significantly greater than groups AB/PRP-100 and AB. Conclusion: It can be concluded that the proportion PRP/AB graft influences bone healing in CSD in rat calvaria.