Osseointegration of implants with superhydrophilic surfaces in rats with high serum levels of nicotine

Abstract This study aimed to evaluate the effect of nicotine administration on the osseointegration of a superhydrophilic implants surface on rat tibiae. Thirty-two rats were used and divided into 2 groups according to the administration or not of nicotine: HH - Installation of implants with superhydrophilic surfaces in healthy animals; and HN - Installation of implants with superhydrophilic surfaces in animals subjected to nicotine administration. The animals were euthanized 15 and 45 days after implant placement (n = 8). Osseointegration was assessed by means of biomechanical analyses (removal torque), microcomputed tomography (volume of bone around the implants- %BV/TV), and histomorphometry (bone-implant contact -%BIC and the bone area between implant threads -%BBT). The animals subject to the nicotine administration presented lower removal torque than the control animals at the 45-day period (21.88 ± 2.80 Ncm vs. 17.88 ± 2.10 Ncm). The implants placed in the control rats presented higher %BIC (54.26 ± 6.59% vs. 39.25 ± 4.46%) and %BBT (50.57 ± 5.28% vs. 32.25 ± 5.24%) than the implants placed in nicotine animals at 15-day period. The nicotine administration reduces the osseointegration at 15 days, however, the superhydrophilic surface equalized the osseointegration in nicotine-exposed animals compared with healthy animals after 45 days of implant placement.

Resumo O objetivo deste estudo foi avaliar o efeito da administração de nicotina na osseointegração de implantes com superfície modificada por jateamento de oxidos e ataque ácido instalados em tíbia de ratos. Foram utilizados 32 ratos que foram divididos em 2 grupos de acordo com a administração ou não de nicotina: HH - Instalação de implantes com superfícies superhidrofílicas em animais sadios; e HN - Instalação de implantes com superfícies superhidrofílicas em animais submetidos à administração de nicotina. Os animais foram eutanasiados 15 e 45 dias após a colocação do implante (n = 8). A osseointegração foi avaliada por meio de análises biomecânicas (torque de remoção), microtomografia (volume de osso ao redor dos implantes - %BV/TV) e histomorfometrica (contato osso-implante -%BIC e área óssea entre roscas do implante -%BBT). Os animais submetidos à administração de nicotina apresentaram menor torque de remoção do que os animais controle no período de 45 dias (21,88 ± 2,80 Ncm vs. 17,88 ± 2,10 Ncm). Os implantes colocados nos ratos controle apresentaram maiores %BIC (54,26 ± 6,59% vs. 39,25 ± 4,46%) e %BBT (50,57 ± 5,28% vs. 32,25 ± 5,24%) do que os implantes colocados nos animais submetidos a administração de nicotina no período de 15 dias. A administração de nicotina prejudicou a osseointegração no período de 15 dias. Entretanto, a superfície superhidrofílica equalizou a osseointegração em animais expostos à nicotina em comparação com animais saudáveis após 45 dias da colocação do implante.

Comparação de diferentes metodologias para análise histométrica de implantes: estudo em ratos / Comparison of different methodologies for histometric analysis of implant. Study in rat

Introdução: Diferentes metodologias tem sido utilizadas para avaliação histológica da osseointegração, levando a diferentes resultados. Objetivo: O objetivo é comparar diferentes metodologias de análise histomorfométrica da osseointegração de implantes com diferentes superfícies, instalados em tíbias de ratos. Material e método: 24 ratos foram aleatoriamente divididos em 3 grupos (n = 8) para a instalação dos implantes. Esses grupos foram divididos de acordo com o tipo de implante instalado na tíbia: Grupo Hidrofílico - HFL (instalação de implante com superfície modificada por jateamento de óxidos e ataque ácido e mantida em solução de cloreto de sódio), Grupo Hidrofóbico - HFB (instalação de implante com superfície modificada por jateamento de óxidos e ataque ácido) e Grupo Usinado - U (instalação de implante com superfície usinada). No período de 45 dias após os procedimentos cirúrgicos de instalação dos implantes, os animais foram submetidos à eutanásia, e as tíbias foram removidas, sendo realizado o processamento histológico para amostras não descalcificadas. Após a obtenção das lâminas, foi realizada a análise histomorfométrica para avaliar as porcentagens de contato osso-implante (% BIC) e da área óssea entre as espiras (% BBT). As mensurações foram realizadas em duas diferentes regiões: 1) as roscas do implante na região do osso cortical e 2) todas as roscas do implante inseridas no osso (cortical e medular). A análise estatística foi feita por meio de ANOVA One-Way, seguida pelo teste de Tukey para análise inferencial dos dados. Resultado: Quando o BIC e o BBT foram analisados de forma independente nas regiões cortical e trabecular/total, observou-se uma diferença no comportamento histológico dos implantes de acordo com o tratamento de superfície. Os implantes HFL apresentaram BIC (%) trabecular 16,85% maior (p = 0,02) do que os implantes HFB e 26,12% maior (p ≤ 0,0001) do que os implantes usinados. Contudo, a região cortical de todos os grupos apresentou valores de BIC cortical significativamente maiores ao redor dos implantes, independentemente da superfície. Conclusão: Os resultados obtidos demonstraram que a formação óssea peri-implantar foi superior nas análises realizadas apenas em osso cortical, se comparados aos valores obtidos na mensuração total (osso cortical somado ao medular). Também foi possível observar que, dentro da mesma superfície, os valores de BIC (%) foram superiores em osso cortical. Em relação às limitações do estudo, pode-se concluir que diferentes metodologias de análise histométrica da osseointegração ao redor de diferentes superfícies de implantes instalados em tíbias de ratos podem interferir nos resultados de osseointegração, independentemente da superfície analisada.

Introduction: Different methodologies were used for histological evaluation of osseointegration, leading to different results. Objective: The objective is to compare different methodologies for histomorphometric analysis of the osseointegration of implants with different surfaces, installed in rat tibias. Material and method: Twenty-four rats were randomly divided into 3 groups (n=8) for implant installation. These groups were divided according to the type of implant that will be installed in the tibia: Hydrophilic Group (installation of an implant with a surface modified by oxide blasting and acid attack and maintained in a sodium chloride solution), Hydrophobic Group (installation of an implant with surface modified by oxide blasting and acid attack) and Machined Group (implant installation with machined surface). Within 45 days after the surgical procedures to install the implants, the animals were euthanized and the tibias were removed, and histological processing was carried out for non-decalcified samples. After obtaining the slides, histomorphometric analysis was performed to evaluate the percentages of bone-implant contact (%BIC) and the bone area between the turns (%BBT). Measurements were carried out in two different regions: 1) the implant threads in the cortical bone region and 2) all implant threads inserted into the bone (cortical and medullary). Statistical analysis was performed using One-Way ANOVA followed by Tukey's test for inferential data analysis. Result: The BIC and BBT were analyzed independently in the cortical and trabecular/total regions, a difference was observed in the histological behavior of the implants according to the surface treatment. HFL implants showed trabecular BIC (%) 16.85% higher (p=0.02) than HFB implants and 26.12% higher (p≤0.0001) than machined implants. However, the cortical region of all groups showed significantly higher cortical BIC values around the implants, regardless of the surface. Conclusion: the results obtained demonstrated that peri-implant bone formation was superior in analyzes carried out only on cortical bone, compared to the values obtained in the total measurement (cortical bone plus medullary bone). It was also possible to observe that, even within the same surface, the BIC(%) values were higher in cortical bone. Within the limitations of the study, it can be concluded that different methodologies for histometric analysis of osseointegration around different surfaces of implants installed in rat tibias can interfere with the results of osseointegration regardless of the surface analyzed

Effects of red and infrared laser on post extraction socket repair in rats subjected to alendronate therapy

Abstract This study evaluated the effect of photobiomodulation therapy (PBMT) with a red or infrared laser on the repair of post extraction sockets in rats administered alendronate (ALN). Forty male rats were randomly allocated into four groups: Control Group (CTR): subcutaneous administration of saline solution throughout the experimental period; Alendronate Group (ALN): subcutaneous administration of alendronate during the entire experimental period; Alendronate/Red Laser Group (ALN/RL): administration of ALN and irradiation with a GaAlAs laser (λ 660 nm); and Alendronate/Infrared Laser Group (ALN/IRL): administration of ALN and irradiation with a GaAlAs laser (λ 830 nm). The first lower molars were extracted 60 days after the beginning of the administration of the drugs. The PBMT was applied after tooth extraction (7 sessions with intervals of 48 hours between sessions). Thirty days after tooth extraction, the animals were euthanized. Micro-CT and histometric analysis were performed to assess the bone healing and soft tissue repair of the tooth socket. The ALN group presented with more bone than the CTR; however, most of this bone was necrotic. ALN does not affect the bone microarchitecture. On the other hand, PBMT with IRL enhances the bone density due to the increase in the number and reduction in the spacing of the trabeculae. The amount of vital bone and connective tissue matrix was higher in the ALN/RL and ALN/IRL groups than in the ALN and CTR groups. PBMT enhanced the healing of the post extraction sockets in rats subjected to ALN administration. Furthermore, IRL improved the new bone microarchitecture.

Implants with hydrophilic surfaces equalize the osseointegration of implants in normo- and hyperglycaemic rats

Abstract The purpose of this study was to evaluate the effect of a surface modified by blasting and acid attack and maintained in an isotonic solution compared to a machined surface on osseointegration in normo- and hyperglycaemic animals. Sixty-four animals were allocated into 4 groups with 16 animals each, and they were subdivided into two experimental periods (15 and 45 days), with 8 animals in each group. The groups were divided according to the type of implant that was installed in the animals' tibia and the animals' systemic condition: CM - Machined implants placed in Healthy animals; CH - Hydrophilic implants placed in Healthy animals, HM - Machined implants placed in animals with hyperglycaemia; HH- Hydrophilic implants installed in animals with hyperglycaemia. The following analyses were performed: biomechanical (removal torque), microtomographic (evaluation of the bone volume around the implants- BV/TV), and histomorphometric (evaluation of bone-implant contact BIC% and of the bone formation area between the threads BBT%). It was found that the implants with hydrophilic surfaces presented higher removal torques and quantities of BV/TV% and higher BIC% and BBT% values in normo- and hyperglycaemic animals. The results of this study indicated that the hydrophilic surface accelerates the osseointegration process (~ 15% BIC/BBT at 15-day period), especially in animals with hyperglycaemia. The hydrophilic surface equaled the osseointegration between normo- and hyperglycaemic animals, reversing the negative potential of hyperglycaemia on the osseointegration process.

Resumo O objetivo deste foi o de avaliar o efeito de uma superfície modificada por jateamento e ataque ácido e mantida em solução isotônica em comparação a uma superfície lisa sobre a osseointegração de implantes em animais hiperglicêmicos. No estudo foram utilizados 64 ratos, que foram divididos em 4 grupos com 16 animais em cada, e que foram avaliados em dois períodos experimentais (15 e 45 dias), com 8 animais em cada grupo. Os grupos foram divididos de acordo com o tipo de implante que foi instalado na tíbia dos animais e a condição sistêmica dos mesmos: Grupo CM - Implantes maquinados instalados em animais saudáveis; Grupo CH - Implantes maquinados instalados em animais com hiperglicemia; Grupo HM - Implantes hidrofílicos instalados em animais saudáveis, Grupo HH- Implantes hidrofílicos instalados em animais com hiperglicemia. Foram realizadas análises: biomecânicas (contra torque de remoção dos implantes), histométricas (avaliação do contato do osso com os implantes e da área de formação óssea entre as roscas) e microtomográfica (avaliação da área óssea ao redor dos implantes). Foi verificado que os implantes com superfície hidrofílica apresentaram maiores torques de remoção, quantidade de osso ao redor dos implantes e maiores valores de %BIC e %BBT em animais normo e hiperglicêmicos. Conclui-se que a superfície hidrofílica acelera o processo de osseointegração (~15% de %BIC/%BBT aos 15 dias), especialmente em animais com hiperglicêmicos. A superfície hidrofílica igualou a osseointegração entre animais normo- e hiperglicêmicos, revertendo o potencial negativo da hiperglicemia no processo de osseointegração.

Comparison of osseointegration in areas grafted with different osteoconductive biomaterials. Preclinical study

Abstract This study evaluated osseointegration in areas grafted with deproteinized bovine bone (DBB) and biphasic ceramic based on hydroxyapatite and beta-tricalcium phosphate (HA/TCP) in rat tibias. Noncritical bone defects were made in the tibias of 28 rats that were randomly assigned to 2 groups: DBB: DBB-filled defects and HA/TCP: HA/TCP-filled defects. Bone defects were made in the tibias bilaterally and filled with biomaterials. After 60 days, the implants were inserted, and the animals were euthanized 15 and 45 days after the implants were installed. Osseointegration was evaluated by biomechanical, microtomographic and histometric analysis. Implants installed in the defects filled with DBB presented higher removal torque forces (2.33 ± 0.51 Ncm vs. 1.50 ± 0.54 Ncm) and mineralized tissue volume around implants at 15 days (34.96 ± 3.68 % vs. 25.61 ± 2.95 %) and greater bone-implant contact (20.87 ± 8.28 % vs. 11.52 ± 7.42 %) and bone area within implant threads (26.83 ± 12.35 % vs. 11.98 ± 7.56 %) at 45 days compared to the measurements of implants in areas grafted with HA/TCP. Implants installed in defects in areas grafted with DBB had a better osseointegration pattern than implants placed in defects in areas grafted with HA/TCP.

Resumo Este estudo avaliou a osseointegração em áreas enxertadas com osso bovino desproteinizado (DBB) e cerâmica bifásica à base de hidroxiapatita e beta-fosfato tricálcico (HA / TCP) em tíbias de ratos. Defeitos ósseos não críticos foram feitos nas tíbias de 28 ratos que foram divididos aleatoriamente em 2 grupos: DBB: defeitos preenchidos com DBB e HA / TCP: defeitos preenchidos com HA / TCP. Defeitos ósseos foram confeccionados nas tíbias bilateralmente e preenchidos com biomateriais. Após 60 dias, os implantes foram instalados e os animais sacrificados 15 e 45 dias após a instalação dos implantes. A osseointegração foi avaliada por análises biomecânica, microtomográfica e histométrica. Os implantes instalados nos defeitos preenchidos com DBB apresentaram maiores forças de torque de remoção (2,33 ± 0,51 Ncm vs. 1,50 ± 0,54 Ncm) e volume de tecido mineralizado ao redor dos implantes aos 15 dias (34,96 ± 3,68% vs. 25,61 ± 2,95%) e maior contato osso-implante (20,87 ± 8,28% vs. 11,52 ± 7,42%) e área de osso dentro das roscas do implante (26,83 ± 12,35% vs. 11,98 ± 7,56%) no período de 45 dias em comparação com os implantes em áreas enxertadas com HA / TCP. Implantes instalados em áreas enxertadas com DBB apresentaram melhor padrão de osseointegração do que implantes colocados em áreas enxertadas com HA / TCP.

Avaliação da perda óssea utilizando diferentes parâmetros na análise microtomográfica: estudo em ratos / Bone loss assessment using different parameters in the microtomographic analysis: study in rats

Introdução: o desafio no uso do Micro-Ct tem sido estabelecer e padronizar padrões adequados para escaneamento e tratamento das imagens, para que se obtenha o máximo desempenho do equipamento, e permitir a comparação dos achados entre diferentes estudos. Objetivo: o presente estudo tem como objetivo comparar a porcentagem de volume ósseo em regiões com perda óssea periodontal utilizando diferentes metodologias para definição da área a ser analisada (ROI). Material e método: dez ratos foram submetidos à indução de doença periodontal, e, após a eutanásia, as mandíbulas foram escaneadas com cortes de 9 µ e 18 µm de espessura, com passo de rotação de 0.3mm. As imagens foram reconstituídas utilizando o software NRecon, e em seguida, utilizando o software CTAnalyser - CTAn, foram definidas as áreas de interesse (ROI) ao redor dos segundos molares. A primeira área de interesse (ROI1) foi definida em um padrão retangular que se restringiu às regiões interproximais e furca, onde a área total de tecido ósseo foi obtida somando os resultados dos 3 ROIs. A segunda área (ROI2) foi definida no sentido corono/apical ao redor do segundo molar até suas limitações proximais com os dentes vizinhos, onde a porcentagem de tecido ósseo pertencente às raízes foram excluídas das avaliações. As análises foram realizadas com cinco diferentes valores de thresholds (130-50, 130-60, 130-70, 130-80, 130-90 e 130-100). Resultado: a análise entre os diferentes ROIs demonstrou que em ambas as análises foi observada a tendência a menor porcentagem de tecido ósseo quanto maior o contraste de tons de cinza utilizado, no entanto, nos resultados obtidos no ROI2 essa diferença não foi estatisticamente significante. Conclusão: com os resultados obtidos pode se concluir que a utilização de diferentes thresholds para quantificação óssea, em áreas onde houve doença periodontal, pode trazer resultados divergentes; a definição da área de interesse interfere com os resultados obtidos e que a obtenção de uma área de interesse com a remoção das raízes mostrou-se menos susceptível à variação dos parâmetros de escaneamento.

Introduction: the challenge in the use of Micro-Ct has been to establish and standardize adequate standards for scanning and image processing to obtain the maximum performance of the equipment and to allow the comparison of findings between different studies. Objective: this study aims to compare the percentage of bone volume in regions with periodontal bone loss using different methodologies to define the area to be analysed (ROI). Material and method: ten rats were submitted to periodontal disease induction, and, after euthanasia, the mandibles were scanned with slices of 9µ and 18 µm thickness, with a rotation step of 0.3mm. The images were reconstructed using the NRecon software, and then, using the CTAnalyser - CTAn software, the areas of interest (ROI) around the second molars were defined. The first area of interest (ROI1) was defined in a rectangular pattern that was restricted to the interproximal and furcation regions, where the total area of bone tissue was obtained by adding the results of the 3 ROIs. The second area (ROI2) was defined in the coronal/apical direction around the second molar to its proximal limitations with the neighboring teeth, in which the percentage of bone tissue belonging to the roots was excluded from the evaluations. Analyses were performed with five different threshold values (130-50, 130-60, 130-70, 130-80, 130-90, and 130-100). Result: the analysis between the different ROIs showed that, in both analyses, there was a tendency towards a lower percentage of bone tissue the greater the grayscale contrast used. However, in the results obtained in ROI2, this difference was not statistically significant. Conclusion: with the results obtained, it can be concluded that the use of different thresholds for bone quantification, in areas where there was a periodontal disease, can bring divergent results; the definition of the area of ​​interest interferes with the results obtained; and that obtaining an area of interest with the removal of the roots, proved to be less susceptible to the variation of the scanning parameters.

LASER in periodontal treatment: is it an effective treatment or science fiction?

Abstract There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

Effect of different low-level intensity laser therapy (LLLT) irradiation protocols on the osseointegration of implants placed in grafted areas

Abstract Objective To evaluate the effect of different protocols of low-level intensity laser therapy (LLLT) irradiation on the osseointegration of implants placed in grafted areas. Methodology 84 rats were randomly allocated into six groups: DBB: defect filled with deproteinized bovine bone; HA/TCP: defect filled with biphasic ceramic of hydroxyapatite/β-tricalcium phosphate ; DBB-LI: defect filled with DBB and treated with LLLT after implant placement; HA/TCP-LI: defect filled with HA/TCP and treated with LLLT after implant placement; DBB-LIB: defect filled with DBB and treated with LLLT after graft procedure and implant placement; and HA/TCP-LIB: defect filled HA/TCP and treated with LLLT after graft procedure and implant placement. The bone defects were made in the tibia and they were grafted. After 60 days, the implants were placed. The rats were subsequently subjected to euthanasia 15 and 45 days after implant placement. The pattern of osseointegration and bone repair in the grafted area was evaluated by biomechanical, microtomographic, and histometric analyses. Furthermore, the expression of bone biomarker proteins was assessed. Results The LLLT groups presented higher removal torque, mineralized tissue volume, and a greater degree of osseointegration, especially when LLLT was performed only after implant placement, and these findings were associated with higher expression of BMP2 and alkaline phosphatase. Conclusion LLLT performed on implants placed in grafted areas enhances the osseointegration process.

Cyclosporine A impairs bone repair in critical defects filled with different osteoconductive bone substitutes

Abstract The aim of this study was to assess the influence of cyclosporine administration on the repair of critical-sized calvaria defects (CSDs) in rat calvaria filled with diverse biomaterials. Sixty animals were divided into two groups: the control (CTR) group (saline solution) and the cyclosporine (CCP) group (cyclosporine, 10 mg/kg/day). These medications were administered daily by gavage, beginning 15 days before the surgical procedure and lasting until the day the animals were euthanized. A CSD (5 mm Ø) was made in the calvaria of each animal, which was allocated to one of 3 subgroups, according to the biomaterial used to fill the defect: coagulum (COA), deproteinized bovine bone (DBB), or biphasic calcium phosphate ceramics of hydroxyapatite and β-phosphate tricalcium (HA/TCP). Euthanasia of the animals was performed 15 and 60 days after the surgical procedure (n = 5 animals/period/subgroup). Bone repair (formation) assessment was performed through microtomography and histometry, while the analyses of the expression of the BMP2, Osteocalcin, and TGFβ1 proteins were performed using immunohistochemistry. The CSDs not filled with biomaterials demonstrated lower bone formation in the CCP group. At 15 days, less bone formation was observed in the CSDs filled with DBB, a smaller volume of mineralized tissue was observed in the CSDs filled with HA/TCP, and the expression levels of BMP2 and osteocalcin were lower in the CCP group compared to the CTR group. The use of cyclosporine impaired bone repair in CSD, and this effect can be partially explained by the suppression of BMP2 and osteocalcin expression.

Cyclosporine A impairs bone repair in critical defects filled with different osteoconductive bone substitutes

Abstract The aim of this study was to assess the influence of cyclosporine administration on the repair of critical-sized calvaria defects (CSDs) in rat calvaria filled with diverse biomaterials. Sixty animals were divided into two groups: the control (CTR) group (saline solution) and the cyclosporine (CCP) group (cyclosporine, 10 mg/kg/day). These medications were administered daily by gavage, beginning 15 days before the surgical procedure and lasting until the day the animals were euthanized. A CSD (5 mm Ø) was made in the calvaria of each animal, which was allocated to one of 3 subgroups, according to the biomaterial used to fill the defect: coagulum (COA), deproteinized bovine bone (DBB), or biphasic calcium phosphate ceramics of hydroxyapatite and β-phosphate tricalcium (HA/TCP). Euthanasia of the animals was performed 15 and 60 days after the surgical procedure (n = 5 animals/period/subgroup). Bone repair (formation) assessment was performed through microtomography and histometry, while the analyses of the expression of the BMP2, Osteocalcin, and TGFβ1 proteins were performed using immunohistochemistry. The CSDs not filled with biomaterials demonstrated lower bone formation in the CCP group. At 15 days, less bone formation was observed in the CSDs filled with DBB, a smaller volume of mineralized tissue was observed in the CSDs filled with HA/TCP, and the expression levels of BMP2 and osteocalcin were lower in the CCP group compared to the CTR group. The use of cyclosporine impaired bone repair in CSD, and this effect can be partially explained by the suppression of BMP2 and osteocalcin expression.

Bone repair induced by different bone graft substitutes in critical-sized defects in rat calvaria / Avaliação do reparo ósseo induzido por diferentes substitutos ósseos em modelo de defeito crítico de calvária de ratos

Abstract Introduction The use of bone substitutes in grafting procedures as an alternative of the use of autogenous bone graft has been indicated, however, the direct comparison between these biomaterials has been little explored. Objective To evaluate the effect of different osteoconductive bone substitutes on the bone repair in critical-sized defects (CSDs) in rat calvaria. Material and method One CSD with an 8 mm diameter was made in each of the 40 rats used in this study. The animals were randomly allocated into 5 groups (n=8), according to the type of bone substitute used to fill the CSD: COA (Coagulum); AUT (autogenous bone); DBB (deproteinized bovine bone graft); HA/TCP (biphasic ceramic composed of hydroxyapatite and β-phosphate tricalcium); and TCP (β-phosphate tricalcium). A microtomographic analysis was performed to evaluate the remaining defect linear length (DLL) of the CSD and the volume of the mineralized tissues (MT) within the CSD at 3, 7, 15 and 30 days after the surgical procedure. In addition, a histometric analysis was performed to evaluate the composition of the repaired bone tissue (% Bone and % Biomaterial) at the 30-day period. Result It was shown that the COA had the lowest DLL and MT within the CSD. In addition, the COA presented the highest % of bone in CSD. The DBB had a higher MT and a higher % of bone substitute particles in the CSD than the AUT and TCP groups. The DBB and AUT groups presented higher % of bone in the CSD than the TCP group. Conclusion The use of the DBB promoted a better pattern of bone volume gain and formation compared to TCP and HA / TCP but was biologically inferior to the AUT.

Resumo Introdução A utilização de substitutos ósseos em procedimentos de enxertia de forma alternativa ao uso do osso autógeno tem sido indicada, entretanto a comparação direta entre esses biomateriais tem sido pouco explorada. Objetivo Avaliar o efeito de diferentes biomateriais osteocondutores sobre o reparo de defeitos críticos em calvárias (DCC) de ratos. Material e método Foram utilizados 40 ratos que foram submetidos a confecção de um DCC com 8 mm de diâmetro. Os animais foram aleatoriamente divididos em 5 grupos com 8 animais, de acordo com o tipo de biomaterial utilizado para preencher os DCC: Grupo COA (coágulo); Grupo AUT (osso autógeno); Grupo OBD (osso bovino desproteinizado); Grupo HA/ TCP (cerâmica bifásica composta de hidroxiapatita e β fosfato tricálcio); Grupo TCP (β fosfato tricálcio). Foram executadas análise microtomográfica para avaliação do comprimento linear remanescente (DLL) do DCC e o volume dos tecidos mineralizados (MT) dentro do DCC nos períodos de 3, 7, 15 e 30 dias após cirurgia. Adicionalmente, foi executado análise histométrica para avaliar a composição do tecido ósseo reparado (% Osso e % Biomaterial) no período de 30 dias. Resultado O grupo COA apresentou o menor DLL e MT dentro do DCC e maior % osso do que os outros grupos. O grupo OBD apresentou maior volume de tecidos mineralizados e maior % biomaterial do que o grupo os grupos AUT e TCP. Os grupos OBD e AUT apresentaram maior % osso que o grupo TCP. Conclusão O OBD promoveu melhor padrão de aumento de disponibilidade óssea e qualidade do osso reparado em comparação ao TCP e HA/TCP, porém biologicamente inferior ao grupo AUT.

Effect of avocado/soybean unsaponifiables on periodontal repair in rats with arthritis and induced periodontitis

Abstract Objective: This study aimed to evaluate the effect of avocado/soybean unsaponifiables (ASU) on periodontal repair in rats with induced periodontitis and arthritis. Methodology: Forty-five rats were submitted to periodontitis induction by insertion of ligatures into the upper second molars, maintained for 15 days. These animals were randomly allocated to 3 groups according to the presence of induced arthritis (ART) and the application of the ASU: Control (CTR) group-healthy animals, where saline solution was administered; ART-animals with induced arthritis, where saline solution was administered; ART/ASU-animals with induced arthritis, where ASU (0.6 mg/ kg) was administered. The drugs were administered daily by gavage and the animals were euthanized after 7, 15 and 30 days of the ligature removal. Bone resorption, inflammatory infiltrate composition and marker proteins expression of the differentiation and formation of osteoclasts (RANKL and TRAP) were assessed. Results: The ART/ASU group presented higher bone volume than the ART group at 7 and 30 days after the ligature removal. Furthermore, the ART group presented higher quantity of inflammatory cells and expression of TRAP and RANKL than the other groups. Conclusion: ASU administration improves the repair of periodontal tissues in an experimental periodontitis model in rats with induced arthritis.

Avaliação da combinação de poli (ácido láctico-co-glicólico) e poli-isopreno (Cellprene®): estudo histológico em ratos / Evaluation of the combination of poly (Lactic-Co-Glycolic Acid) and polyisoprene (Cellprene®) materials: histological study in rats

Resumo Introdução A quantidade e qualidade óssea na implantodontia é um fator de alta relevância quando se tem por objetivo instalar implantes e reabilitar pacientes. No entanto, essa disponibilidade é comprometida na maioria dos casos, havendo a necessidade da busca de novos biomateriais, membranas e substâncias para uma regeneração mais favorável. Objetivo: O objetivo deste estudo foi avaliar a resposta da neoformação óssea em defeitos críticos em calvárias de ratos utilizando scaffolds de fibras de blenda polimérica a partir de poli (ácido láctico-co-glicólico) e poli-isopreno (Cellprene®). O projeto foi aprovado pelo Comitê de Ética em Experimentação Animal. Material e método Neste estudo, foram utilizados 36 ratos (Rattus Norvegicus), variação albinus, Holtzman, adultos. Os animais foram submetidos à tricotomia na região da calota craniana e à confecção de defeitos ósseos circulares bilaterais com 5 mm de diâmetro. Os animais foram divididos em três grupos: GC - defeito sem colocação de biomaterial; GCol - scaffolds de colágeno (Bio-Gide, da empresa Geistlich Pharma Ag - Biomaterials); GPoli - scaffolds de fibras de blenda polimérica a partir de poli (ácido láctico-co-glicólico - Cellprene®). Cada grupo foi avaliado em quatro períodos experimentais (7, 15, 30 e 60 dias). Após esses períodos, os animais foram sacrificados, e as peças passaram por tramitação laboratorial de rotina e inclusão em parafina. Foram obtidos cortes semisseriados e corados pela técnica de hematoxilina e eosina para análise histométrica e histológica. Foi executada análise histométrica para avaliar a composição do tecido ósseo reparado (% osso). Os dados obtidos foram analisados estatisticamente com nível de significância de 95%. Resultado Foi verificado que o GCol apresentou maior preenchimento do defeito nos períodos de 30 e 60 dias em comparação aos GC e GPoli. Conclusão Os scaffolds de fibras de blenda polimérica a partir de poli (ácido láctico-co-glicólico) e poli-isopreno (Cellprene®) não apresentaram vantagens quando utilizados em defeitos críticos.

Abstract Introduction The bone quantity and quality in implant dentistry is a highly relevant factor when it aims the use of implants and rehabilitation in patients. However, this availability is compromised in most cases, with the need to research new biomaterials, membranes and substances for more favorable regeneration. Objective: The aim of this study was to evaluate the response of bone neoformation in critical defects in rat calvaries using polymeric blend fiber scaffolds from Poly (Lactic-Co-Glycolic Acid) and Polyisoprene (Cellprene®). The project was approved by the Animal Experimentation Ethics Committee. Material and method In this study 36 rats (Rattus Norvegicus), variation albinus, Holtzman, adults were used. The animals had trichotomy in the region of the skull and the confection of bilateral circular bone defects with a diameter of 5 mm. The animals were divided into 3 groups: Group GC - defect without biomaterial placement, Group GCol - collagen scaffolds (Bio-Gide, from Geistlich Pharma Ag - Biomaterials), Group GPoli - polymeric blend fiber scaffolds from Poly (Lactic-Co-Glycolic Acid)-Polyisoprene. Each group was evaluated in 4 experimental periods (7, 15, 30 and 60 days). After these periods the animals were sacrificed and the pieces underwent routine laboratory procedures and paraffin embedding. Semi-serial sections were obtained and stained by hematoxylin and eosin technique for histometric and histological analysis. Histometric analysis was performed to evaluate the composition of repaired bone tissue (% Bone). The data obtained were statistically analyzed with a significance level of 95%. Result It was found that the GCol group presented greater defect filling in the 30 and 60 days periods compared to the GC and GPoli groups. Conclusion Polymer blend fiber scaffolds from Poly (Lactic-Co-Glycolic Acid) and Polyisoprene (Cellprene®) did not have advantages when used in critical defects.

Tratamento de recessões múltiplas bilaterais com matriz colágena (Mucograft) e enxerto de conjuntivo / Treatment of bilateral multiple recessions with connective tissue graft and collagen matrix (Mucograft)

Atualmente, várias abordagens cirúrgicas têm sido propostas para o tratamento das recessões gengivais. Dentre as técnicas descritas, o uso do enxerto de tecido conjuntivo demonstrou ser efi caz e previsível, sendo considerado o padrão-ouro para o recobrimento radicular. No entanto, essa técnica demanda mais tempo operatório devido à necessidade de um segundo sítio cirúrgico para a remoção do enxerto, podendo aumentar a morbidade e o desconforto ao paciente. Visando reduzir essa possibilidade, novos biomateriais têm sido propostos, incluindo as membranas de colágeno de origem suína. O objetivo desse relato de caso foi comparar o recobrimento radicular de recessões múltiplas, utilizando a matriz de colágeno Mucograft e o enxerto de tecido conjuntivo, após 12 meses de acompanhamento.

Currently several surgical approaches have been proposed for the treatment of gingival recessions. Among the techniques described, the use of the connective tissue graft was shown to be effective and predictable, being considered the gold standard for root coverage. However, this technique requires more operative time due to the need for a second surgical site for graft removal, which may increase morbidity and discomfort for the patient. Aiming to reduce discomfort to the patient, new biomaterials have been proposed including porcine collagen membranes. The objective of this clinical case report was to compare the root coverage of multiple recessions using the Mucograft collagen matrix and the connective tissue graft after 12 months of follow-up.

Effects of avocado/soybean unsaponifiables (ASU) on the treatment of ligature-induced periodontitis in rats

Abstract The purpose of this study is to evaluate the effect of the avocado/soybean unsaponifiables (ASU) on the treatment of induced periodontitis in rats. Periodontitis was induced in 84 rats via ligature placement around the second upper molar, which was removed after 7 days, and scaling and root planning (SRP) was performed at this time. Subsequently, the rats were randomly allocated to four groups with 21 animals each: One SRP group in which saline solution was administered (SS), and three groups in which ASU was administered (0.6 g/kg/day), beginning either 7 days before the induction of periodontitis (SRP/ASU-7), on the day of periodontitis induction (SRP/ASU0), or on the day of treatment (SRP/ASU+7). ASU and SS were administered daily by gavage until the sacrifice of the animals (7, 15, and 30 days after SRP). The % bone in the furcation area was evaluated by histomorphometry and micro-CT. The expression of proteins (TRAP, RANKL, and alkaline phosphatase) and mRNA (IL-1β, TNF-α, IL-6, RANKL, and alkaline phosphatase) were evaluated by immunohistochemistry and qPCR. The SRP/ASU+7 group presented a higher percentage of bone fill in the furcation area and higher expression of alkaline phosphatase than in the SRP group (at 7 and 30 days, respectively). The SRP/ASU0 and SRP/ASU+7 groups presented lower expression levels of RANKL mRNA than the SRP and SRP/ASU-7 groups at 15 days. ASU administration on the day of the SRP treatment of the ligature-induced periodontitis promoted subtle beneficial effects on periodontal repair following the treatment of induced periodontitis within the experimental period of 7 days.

Avaliação histomorfométrica da associação entre biovidro e osso bovino liofilizado no tratamento de defeitos ósseos críticos criados em calvárias de ratos. Estudo piloto / Histomorphometric evaluation of the association between bioglass and lyophilized bovine bone in the treatment of critical bone defects created on rat calvaria: a pilot study

Objetivo: Avaliar histomorfometricamente o efeito de biovidro (B), osso bovino liofilizado (OB) ou da mistura desses dois biomateriais (B/OB - 1:1) no reparo de defeitos ósseos críticos em calvária de ratos. Material e Método: Defeitos ósseos (8 mm Ø) foram criados cirurgicamente na calvária de 24 ratos, distribuídos em 4 grupos com 6 animais, de acordo com o tipo de biomaterial: coágulo sanguíneo (GC), biovidro (GB), osso bovino liofilizado (GOB) e a mistura desses dois biomateriais (GB/OB). Os animais foram eutanasiados após 15 e 60 dias do procedimento cirúrgico (3 animais por período). A avaliação histológica foi baseada na descrição da morfologia dos tecidos neoformados, enquanto para a avaliação histomorfométrica foi realizada quantificação da porcentagem de tecido ósseo, de tecido conjuntivo fibroso neoformados e de biomaterial remanescente no defeito ósseo. Resultado: Nos dois períodos experimentais, a análise histológica apresentou neoformação óssea, principalmente nas bordas dos defeitos, e ao redor de partículas de biomateriais remanescentes. A avaliação histomorfométrica demonstrou que no período de 15 dias o grupo GC apresentou maior percentagem de tecido ósseo em relação aos demais grupos estudados, enquanto que aos 60 dias o grupo GOB apresentou maior porcentagem de tecido ósseo em relação ao grupo GB. Conclusão: O osso bovino liofilizado apresentou maior formação óssea em relação ao biovidro, mas nenhum dos biomateriais foi superior ao coágulo. A associação do biovidro e osso bovino liofilizado não adicionou vantagem à formação óssea. .

Objective: This study sought to histomorphometrically evaluate the effect of bioglass (B), lyophilized bovine bone (BB) or the 1:1 mixture of these two biomaterials on the repair of critical bone defects in rat calvaria. Material and Method: Bone defects (8 mm Ø) were surgically created in the calvaria of 24 rats, which were divided into the following 4 groups of 6 animals each according to the type of biomaterial used: blood clot / coagulum (control) group (CG), bioglass group (BG), lyophilized bovine bone group (BBG) and a group receiving a mixture of these two biomaterials (BG/BB). The animals were euthanized at 15 or 60 days after surgery (3 animals per period). Histological evaluation was based on the morphological description of the newly formed tissues, and a quantification of the percentage of bone tissue with newly formed fibrous connective tissue and the percentage of biomaterial remaining in the bone defect was performed for the histomorphometric evaluation. Result: In both experimental periods, the histological analysis showed new bone formation, especially at the edges of the defects and around remaining biomaterial particles. Histomorphometric analysis showed that the CG contained a higher percentage of bone tissue over the 15-day period compared to that of the other groups. At 60 days, the BBG showed a higher percentage of bone tissue compared to that of the BG (p <0.01). Conclusion: Lyophilized bovine bone led to greater bone formation compared to bioglass, but none of the biomaterials was superior to blood clot. Moreover, the combination of bioglass and lyophilized bovine bone did not provide an advantage for bone formation. .

Influence of supragingival biofilm control and smoking habit on Interleukin-1β concentration

This investigation compared gingival crevicular fluid (GCF) interleukin-1β (IL-1β) concentrations in periodontitis patients subjected to a strict supragingival biofilm control (Supra) for 6 months. Never-smokers (23) and smokers (n = 20; 19.6 ± 11.8 cigarettes/day) moderate-to-severe chronic periodontitis patients underwent a 6 months period of supragingival control with weekly recall visits. Periodontal probing depth (PPD), bleeding on probing (BOP) and GCF samples (from different PPD category sites: 3-5 mm and 6–10 mm) were obtained at the baseline, 30, and 180 days. IL-1β was assessed by enzyme-linked immunosorbent assay. Generalized estimating equations were used to fit prediction models of IL-1β changes, considering the dependence between the examinations, and using only data from experimental sites. Overall IL-1β concentrations decreased from 3.2 pg/µL to 1.9 pg/µL. Higher baseline IL-1β concentrations were associated with higher baseline PPD values in both groups. There were no differences in IL-1β concentrations between never-smokers and smokers over time for any PPD category. Higher baseline PPD values and the presence of BOP on day 180 were significantly associated with higher IL-1β concentrations. A strict Supra regimen reduced IL-1β concentrations over time in periodontitis patients. The benefits observed for smokers underline the importance of oral hygiene measures, even considering the presence of this important risk factor.

Efeito do ângulo de trabalho do ultrassom e do jato de bicarbonato sobre as superfícies ranculares / Effect of the working angle of the ultrasound and the air-polishing on root surfaces

O objetivo deste estudo foi avaliar o efeito da variação do ângulo de trabalho do ultrassom magnetoestrictivo (UM) e do jato de bicarbonato (JB) sobre a rugosidade e o desgaste de raízes dentárias. Cinquenta dentes bovinos tiveram as superfícies proximais divididas em três regiões: coronal, média e apical. A região coronal foi tratada com um instrumento manual, a região apical foi tratada com o JB ou com o UM, e a região média foi mantida sem tratamento para servir como controle. Os dentes foram divididos em 11 grupos, de acordo com o tratamento aplicado e o ângulo de trabalho: UM-0°; UM-30°; UM-45°; UM-60°; UM-90°; JB-0°; JB-30°; JB-45°; JB-60°; JB-90'; PAR: instrumento manual. O teste Anova, complementado pelo teste de Tukey, foi utilizado para a análise estatística (p < 0,05). A PAR promoveu menor rugosidade e maior desgaste dentário em comparação com os valores obtidos com o UM e o JB (p <0,05). Os ângulos de 450, 600 e 90° causaram maiores desgastes e rugosidades quando o UM foi utilizado (p < 0,05), enquanto o angulo de 900 causou maiores desgastes que o angulo de 300, quando o JB foi utilizado (p < 0,05). Pôde-se concluir que o tanto o UM como o JB produziram menores desgastes e maiores rugosidades às superfícies radiculares que a raspagem com instrumentos manuais. O angulo de trabalho influenciou no desgaste e na rugosidade promovidos pelo UM, enquanto que, ao utilizar o JB, a variação do angulo de trabalho influenciou apenas no desgaste radicular.

Análise da morfologia e da adesão de elementos sanguíneos em superfícies radiculares instrumentadas com ultrassom piezoelétrico: estudo in vitro / Morphology and adhesion on blood components in root surfaces treated by a piezoelectric ultrasonic: an in vitro study

Objective: The aim of this study was to evaluate the morphology and adhesion of blood components on root surfaces instrumented with piezoelectric ultrasonic Piezon Master Surgery. Methods: 10 teeth were used in this study. The teeth had their proximal divided into four areas that received different treatments: Group 1: untreated control Group 2: scaling with manual instrument; Group 3: scaling with ultrasound; Group 4: Scaling with manual instruments and ultrasound. We obtained 20 samples, 10 of which were used to analyze the morphology and the other 10 were used for analysis of adhesion of blood components. The specimens were analyzed by scanning electron microscopy. Photomicrographs were analyzed by the scores of adhesion of blood components and the index of root morphology. The results were statistically by the Kruskall-Wallis and Mann-Whitney with a significance level of 95%. Results: The morphological analysis showed that the Group 1 had a surface unchanged in relation to other groups (Group 1 X Group 2 = 0.0025;Group 1 X Group 3 = 0.0003; Group 1 X Group 4 = 0.0003) and Group 2 presented a smoother surface compared to Group 1 and groupsinstrumented with ultrasound (Group 2 X Group 3 = 0.0025; Group 2 X Group 4 = 0.0025) there were no statistical differences betweenthe Groups 3 and 4. analysis of adhesion of blood components showed that the Groups 2, 3 and 4 had no statistically significant differencesbetween themselves, but more biocompatible surfaces promoted the surface untreated control (Group 1 X Group 2 = 0.02; Group 1 X Group3 = 0.04; Group 1 X Group 4 = 0.005). Conclusion: The instrumentation with piezoelectric ultrasonic promoted an irregular root surface, but did not negatively affect the adhesion of blood components.

Objetivo: Avaliar a morfologia e a adesão de células sanguíneas em superfícies radiculares instrumentadas com o ultrassom piezoelétrico Piezon Master Surgery. Métodos: Foram utilizados nesse estudo 10 dentes que tiveram suas proximais divididas em 4 áreas que receberam diferentes tratamentos: Grupo 1: controle sem tratamento; Grupo 2: raspagem com instrumento manual; Grupo 3: raspagem com ultrassom; Grupo 4: associação instrumento manual e ultrassom. Foram obtidas 20 amostras, sendo que 10 foram utilizadas para análise da morfologia e as outras 10 foram utilizadas para a análise de adesão de elementos sanguíneos. Os espécimes foram analisados em microscópio eletrônico de varredura. As fotomicrografias foram analisadas através dos scores de adesão de elementos sanguíneos e pelo índice de morfologia radicular e os resultados foram analisados estatisticamente através dos testes de Kruskall-Wallis e de Mann-Whitney com nível de significância de 95%.Resultados: A Análise morfológica demonstrou que o Grupo 1 apresentou uma superfície inalterada em relação aos outros grupos (Grupo 1 X Grupo 2 = 0.0025; Grupo 1 X Grupo 3 = 0.0003; Grupo 1 X Grupo 4 = 0.0003), e o Grupo 2 apresentou uma superfície mais lisa em relação ao Grupo 1e aos grupos instrumentados com ultrassom (Grupo 2 X Grupo 3 = 0.0025; Grupo 2 X Grupo 4 = 0.0025). Não houve diferenças estatísticasentre os Grupos 3 e Grupo 4. A análise de adesão de elementos sanguíneos demonstrou que o Grupo 2, Grupo 3 e Grupo 4 não apresentaram diferenças estatisticamente significantes entre si, porém promoveram superfícies mais biocompatíveis que a superfície controle sem tratamento (Grupo 1 X Grupo 2 = 0.02; Grupo 1 X Grupo 3 = 0.04;Grupo 1 X Grupo 4 = 0.005). Conclusão: A instrumentação com ultrassom promoveu uma superfície radicular irregular, porém não afetou negativamente a adesão de elementos sanguíneos.