Physico-Chemical comparison of four commercially available mineral trioxide aggregates / Comparación fisicoquímica de cuatro mineral trióxido agregados disponibles comercialmente

Abstract To compare the physicochemical composition of 4 MTAs commercially available in Latin America. ProRoot MTA (Dentsply, USA), MTA Angelus (Angelus, Brazil), MTA Flow (Ultradent, USA), and MTA Viarden (Viarden, Mexico) were physically and chemically compared. Scanning electron microscopy (SEM) images were obtained from the MTA powder and the prepared presentations. Energy Dispersive X-Ray Spectroscopy (EDS) analyses were performed by triplicate, to calculate the mass proportion of calcium (Ca), silicon (Si), the Ca/Si proportion among the 4 brands. Thermogravimetric analyses (TGA) were conducted (50ºC-1000ºC), and mass loss and inflection points were calculated for each material. Statistical differences for Ca and Si content were determined by ANOVA (p<0.05). SEM images showed evident differences in the appearance of both the powder and the prepared MTAs among brands. Angelus MTA showed cubic prisms not observed in the other 3 brands. ProRoot MTA and MTA Flow showed similar homogeneous structures. MTA Viarden was the less homogeneous, with random structures (>15um). When comparing the mass proportions of Ca and Si between the 4 powder samples, MTA Viarden showed a significantly lower proportions of both elements when compared with the other brands (p<0.005). TGA análisis showed a similar behavior for ProRoot MTA, MTA Angelus and MTA Flow, with less than 2% mass loss when the 1000C temperature was reached. MTA Viarden showed a mass loss of 9,94% before the 700C, indicating the presence of different content sensible to temperature degradation. The analyzed MTAs demonstrated to vary significantly in their chemical composition and physical characteristics. Clinicians must be aware of the differences between different brands of a same material, and future research should focus on the clinical implications of these differences.

Resumen Comparar la composición fisicoquímica de 4 MTA disponibles comercialmente en América Latina. Se compararon física y químicamente ProRoot MTA (Dentsply, EE. UU.), MTA Angelus (Angelus, Brasil), MTA Flow (Ultradent, EE. UU.) y MTA Viarden (Viarden, México). Se obtuvieron imágenes de microscopía electrónica de barrido (SEM) del polvo de MTA y de las presentaciones preparadas. Los análisis de espectroscopía de dispersión de energía de rayos X (EDS) se realizaron por triplicado para calcular la proporción de masa de calcio (Ca), silicio (Si), la proporción Ca/Si entre las 4 marcas. Se realizaron análisis termogravimétricos (TGA) (50ºC-1000ºC), y se calcularon las pérdidas de masa y los puntos de inflexión para cada material. Las diferencias estadísticas para el contenido de Ca y Si se determinaron mediante ANOVA (p<0,05). Los análisis SEM mostraron diferencias evidentes en la apariencia tanto del polvo como las preparaciones de los MTA, entre las diferentes marcas. MTA Angelus mostró prismas cúbicos no observados en las otras 3 marcas. ProRoot MTA y MTA Flow mostraron estructuras homogéneas similares. MTA Viarden fue el menos homogéneo, con estructuras aleatorias (>15um). Al comparar las proporciones de masa de Ca y Si entre las 4 muestras de polvo, MTA Viarden mostró proporciones significativamente más bajas de ambos elementos en comparación con las otras marcas (p<0,005). El análisis TGA mostró un comportamiento similar para ProRoot MTA, MTA Angelus y MTA Flow, con menos del 2 % de pérdida de masa al alcanzar los 1000 °C de temperatura. El MTA Viarden mostró una pérdida de masa de 9,94% antes de los 700 °C, indicando la presencia de diferentes contenidos sensibles a la degradación por temperatura. Los MTA analizados demostraron diferencias significativas en su composición química y características físicas. Los clínicos deben ser conscientes de las diferencias entre las diferentes marcas de un mismo material, y futuras investigaciones deben enfocarse en las implicaciones clínicas de estas diferencias.

Apexificación en una cita utilizando material biocerámico como tapón apical / Apexification in a single appointment using a bioceramic material as an apical plug

El objetivo fue realizar una técnica de apexificación en una cita, evaluando clínica y radiográficamente la formación de barrera dura apical, con seguimiento a nueve meses, al utilizar material biocerámico en dien-tes permanentes jóvenes. Se trataron 30 incisivos su-periores permanentes con ápice abierto y anteceden-tes de trauma, en pacientes de ambos géneros y 18-40 años. Las piezas (n=30) se dividieron en dos grupos (n=15). Grupo experimental: tratamiento de apexifica-ción con EndoSequence Root Repair Material (EERR), y grupo control: tratamiento con impresión apical. Se determinaron distribuciones de frecuencias y esta-dísticas descriptivas para cada variable, según es-cala de medición y distribución. Se realizaron IC 95%, test de Chi cuadrado con cálculo de residuos estan-darizados ajustados y test de Fisher. Se fijó nivel de significación p=0.05. Las diferencias de manifestacio-nes preoperatorias y postoperatorias según grupo fueron no significativas (p Fisher = 0.9140) y (p Fisher = 0.992), respectivamente. No se hallaron diferencias entre proporciones de hallazgos radiológicos preope-ratorios según grupo. Medidas trimestralmente, no hubo diferencias significativas entre proporciones de piezas con continuidad de cortical ósea y radiolucidez periapical postoperatoria según grupo, (p Fisher = 0.7780) y (p Fisher = 0.7909), respectivamente. Debi-do la escasa cantidad de trabajos que reportan el uso de EERR para esta técnica, se requiere de nuevos en-sayos clínicos con tamaños muestrales amplios, para compararlo con otros materiales y técnicas, y deter-minar si su tasa de éxito a largo plazo es mayor que a de los materiales y técnicas usadas actualmente (AU)

To perform apexification technique in one appointment, clinically and radiographically evaluating the formation of apical hard barrier, with follow-up at nine months, when using bioceramic material in young permanent teeth. Materials and methods: 30 permanent upper incisors with open apex and history of trauma were treated, in patients of both genders and 18-40 years of ages. The teeth (n=30) were divided into two groups (n=15). Experimental group: apexification treatment was performed with EndoSequence Root Repair Material (EERR), control group: treatment with apical impression. Frequency distributions and descriptive statistics were determined for each variable according to scale of measurement and distribution. 95% CI, Chi-square test with calculation of adjusted standardized residuals and Fisher's test were performed. The level of significance p=0.05 was set. The differences in preoperative and postoperative manifestations according to group were not statistically significant (Fisher's p = 0.9140) and (Fisher's p = 0.992), respectively. No differences were found between proportions of preoperative radiological findings according to group. Measured quarterly, there were no significant differences between proportions of teeth with bone cortical continuity and with postoperative periapical radiolucency according to group, (p Fisher = 0.7780) and (p Fisher = 0.7909), respectively. Due to the small number of works that report its use for this technique, is necessary to carry out new clinical trials with larger sample sizes, to compare it with other materials and techniques, and determine if its success rate in the long term is greater than that of currently used materials and techniques (AU)

Reimplante intencional: que procedimento é esse que pode salvar dentes? Dois relatos de caso em longo prazo / Intentional replantation: What kind of approach is this that can save teeth? Two long term case reports

Introdução: A manutenção da dentição natural é preferível na maioria dos casos. Muito embora hoje em dia se possa contar com os implantes dentários, em casos com prognóstico menos limitado a preservação dos dentes ainda é mais aconselhável que os implantes. A Endodontia, e todas as suas possibilidades terapêuticas existentes, intenta e faz o papel de especialidade que tem como princípio prevenir ou eliminar a periodontite apical, dando condições de reparo e saúde ao periodonto apical e tecido ósseo. Com o advento tecnológico dos últimos anos, os tratamentos de canal se tornaram muito mais previsíveis e isso se reflete no aumento dos índices de sucesso, tanto de tratamentos primários quanto de retratamentos. Contudo, existem casos que falham, mas esses casos não são o fim da linha para o dente. Entre as manobras existentes para se reintervir em dentes que tiveram um tratamento que fracassou, são possíveis a microcirurgia endodôntica apical ou o reimplante intencional. Método: A manobra de reimplante intencional consiste de várias etapas cirúrgicas que vão desde a extração do elemento dental até a reposição de volta ao seu alvéolo. Neste artigo foram descritos dois casos clínicos limítrofes que foram tratados por meio desse procedimento. Resultados: Os casos apresentaram resultados excelentes, como remissão das lesões apicais, reparo ósseo e permanência dos elementos em boca, com acompanhamento de longo prazo (2 e 11 anos). Conclusões: Com altos índices de sucesso já relatados na literatura, essa modalidade de tratamento precisa ser mais explorada e divulgada no Brasil, principalmente entre alunos de pós-graduação e especialistas em Endodontia, pois comprovadamente pode evitar a indicação desnecessária de implantes dentais (AU).

Introduction: The maintenance of natural dentition is preferable in most of cases. However, nowadays it is possible to use dental implants in cases where prognosis is very limited. Endodontics and all of its therapeutic modalities play an important role, which has, in principle, to prevent or eliminate apical periodontitis providing better conditions for wound healing of periapical and bone tissues. In the past few years, with technological advances, root canal treatment became more predictable and this can be seen reflected in the increase of success rates of primary treatment as well as non-surgical retreatment. Nevertheless, some cases can failure but, it is not the end for the tooth, once some therapeutic approaches are possible, like apical microsurgery or intentional replantation. Method: Intentional replantation is an approach in which some surgical steps are done, since the dental extraction until its repositioning back to the socket. In this article two bordering cases were described. Results: 2 and 11 years follow-up confirm the favorable results of this technique. Both cases with no apical lesion, bone healing and dental elements developing their natural functions. Conclusions: The high successful rates described in the literature give to this treatment approach an important face, and that should be more explored and disclosed in Brazil, specially between specialists and post-graduation students, once can avoid unnecessary dental implants (AU).

Tratamiento no quirúrgico de lesión periapical de gran tamaño: Reporte de caso / Non-surgical Therapeutics of large size periapical injury: Clinical case report

Resumen Se describe un caso clínico sobre una mujer de 21 años de edad la cual sufrió trauma dental a los 6 años que comprometió al incisivo superior izquierdo lo cual con el tiempo generó o se formó una gran lesión periapical en esta región. Radiográficamente se observa la formación incompleta de la raíz, las paredes del conducto radicular delgadas, y una extensa lesión periapical. Se realizó el desbridamiento químico-mecánico con limas K y se ejecutó la desinfección del conducto radicular con clorhexidina al 2%. El conducto se deja medicado con hidróxido de calcio (Vitapex®), el cual se reemplaza periódicamente con dicho material hasta los nueve meses, finalmente se obtura con Biodentine®. Se da seguimiento al caso a través de cuatro años, pasando por blanqueamiento interno, carilla de resina hasta llegar a poste intra radicular con corona completa de porcelana en lo concerniente al aspecto estético. En cuanto a la lesión periapical de gran tamaño, se llega a observar por medio de tomografías, disminución de la lesión al mínimo y genera cicatrización ósea. En relación con la observación clínica hay desaparición de la fístula y ausencia de sintomatología.

Abstract This report describes a clinical case involving a 21-year-old woman, who suffered dental trauma at age 6, compromising left tooth 2.1. On time she developed a large periapical injury in this area. Radiographically, incomplete root formation, thin walls of the root canal, and extensive periapical damage is clearly shown. Chemo- mechanical debridement was performed with K files and disinfection of the root canal using 2% chlorhexidine. The root canal was left medicated with calcium hydroxide (Metapex), which was replaced periodically until 9 months. Finally, the root canal was completely sealed with Biodentine. The case had a follow up for over four years and concerning esthetical aspects, through this period of time an internal whitening, resin veneer, intra radicular post and complete crown were provided. Regarding the considerable periapical injury, tomography shows that it has been drastically reduced and generated bone healing. Clinical observations also show that the fistula and symptomatology disappeared.

Biocerámicos: aspectos farmaco-tecnológicos y clínicos de uso odontológico / Bioceramics: pharmatechnological and clinical aspects of dental use

Se analizan aspectos fármaco-tecnológicos y clínicos de biocerámicos bioabsorbibles compuestos por biovidrios con capacidad osteogénica y microbicida, para ser utilizados como relleno bioactivo en el conducto radicular y como tratamiento terapéutico en el sitio de a lesión apicoperirradicular de origen endodóntico. Mediante un diagrama ternario se consideraron las diversas variables cuyos valores determinan las diferentes fases de los vidrios bioactivos, hasta alcanzar la formación de hidroxiapatita, cuando se someten a un medio biológico. Se analizaron composición y mecanismo de acción en la reparación posendodóntica, que parte de la integración del biomaterial al tejido duro sano, sin formación de fibrosis o proceso inflamatorio inmune (AU)

Pharmacotechnological and clinical aspects of bioabsorbable bioceramics composed of bioglasses with osteogenic and microbicidal capacity are analyzed, to be used as a bioactive filler in the root canal and as a therapeutic treatment at the site of an apicoperiradicular lesion of endodontic origin. By means of a ternary diagram, the various variables whose values determine the different phases of the bioactive glasses were considered, until reaching the formation of hydroxyapatite, when subjected to a biological medium. Composition and mechanism of action were analyzed in post-endodontic repair, which starts from the integration of the biomaterial into healthy hard tissue, without the formation of fibrosis or an immune inflammatory process (AU)

Micro-morphology and phase of zirconia-based nano-hydroxyapatite functional gradient biomaterials / 中国组织工程研究

BACKGROUND: The successfully prepared zirconia-based nano-hydroxyapatite functional gradient bioceramics has mechanical properties of strong interlayer bonding, high compressive and shear strength, but its biological properties are yet to be studied. OBJECTIVE: To detect the micro-morphology and phase of the zirconia-based nano-hydroxyapatite functional gradient bioceramics using scanning electron microscope and X-ray diffractometer. METHODS: Cylindrical zirconia-based nano-hydroxyapatite functional gradient bioceramics were longitudinally sectioned into thin-shaped specimens with turbine handpieces. The profile (intersections of layers) was polished with sandpaper. Its surface micro-morphology and layered structure were observed with a scanning electron microscope after spraying gold. The test piece was ground into a powder in an agate mortar and filtered with gauze. Ceramic powder was sieved with smaller particle size for phase analysis with X-ray diffractometer. RESULTS AND CONCLUSION: (1) Scanning electron microscopy showed that the gradient layers were tightly bound. The grain volume was basically uniform. There was a small amount of ZrO2 agglomeration. The closer to the surface layer, the higher the nHA content and the uniform small pores. (2) The X-ray diffractometer detected mainly the tetragonal phase ZrO2 and nHA diffraction peaks, and a small amount of β-TCP, α-TCP, CaZrO3 and a small amount of monoclinic phase ZrO2 crystal. (3) The research results indirectly indicate that the surface layer nHA is firmly bonded to the ZrO2 matrix layer under the transition of the gradient layer. ZrO2 based nHA functional gradient biomaterial is a ceramic material with excellent mechanical and biological properties.

Resistencia a la Fractura de Dientes Tratados Endodónticamente Obturados con Selladores Biocerámicos Versus Selladores Resinosos. Revisión Sistemática / Fracture Resistance of Endodontically Treated Teeth Obturated with Bioceramic Sealers and Epoxy Resin-Based Sealers. A Systematic Review

RESUMEN: El objetivo de este estudio fue determinar mediante la revisión de la literatura científica disponible cuál es el tipo de cemento sellador que proporciona mayor resistencia a la fractura en dientes tratados endodónticamente, los cementos a base de biocerámicos o los en base a resina epóxica. Se realizó una revisión sistemática de acuerdo a las bases de los estamentos de PRISMA, en las bases de datos Medline, SciELO, Trip Database, LILACS, Web of Science, Cochrane. Se realizó la búsqueda a 10 años y se incluyeron sólo estudios in vitro. Se encontraron 202 artículos, luego se eliminaron los artículos duplicados y se excluyeron los estudios no atingentes por título y resúmenes, quedando ocho artículos que se revisaron a texto completo. En esta etapa se excluyeron dos estudios. Un total seis estudios fueron incluidos en esta revisión. De estos, ninguno encontró diferencia significativas entre cementos selladores a base de biocerámicos y a base de resina epóxica, en cuanto a resistencia a la fractura de los dientes tratados endodónticamente. Sin embargo, en 4 estudios los valores más altos encontrados de resistencia a la fractura estuvieron dados por los selladores en base a resina epóxica. Los artículos seleccionados, teniendo en consideración las limitaciones propias de los estudios in vitro, concluyen que en cuanto a resistencia a la fractura no hay diferencias significativas entre el uso de cementos selladores a base de biocerámicos y cementos selladores a base de resina epóxica en la obturación radicular de dientes tratados endodónticamente.

ABSTRACT: The objective of this study was to determine through the review of scientific literature, the type of sealer that provides the greatest resistance to fracture in endodontically treated teeth. Bioceramic sealer or epoxy resin based sealers were considered for this analysis. A systematic review was performed according to PRISMA, in the databases Medline, SciELO, Trip Database, LILACS, Web of Science, Cochrane. The search was carried out over the last 10 years, and only in vitro studies were included; 202 articles were found and subsequently, duplicate articles were eliminated, non-inferential studies by title and abstracts were excluded, leaving eight articles that were revised to full text. In this stage, two studies were excluded. In total, six studies were included in this review. Of these, none found significant difference between sealer cements based on bioceramics and based on epoxy resin, in terms of resistance to fracture of endodontically treated teeth. However, in 4 studies the highest found values of fracture resistance were given by sealers based on epoxy resin. Taking into account the limitations inherent to in vitro studies, this review concludes that in terms of fracture resistance, there are no significant differences between the use of sealer based on bioceramics and the based on epoxy resin in the root canal obturation.

Research progress of pulpotomy and crown pulp regeneration / 口腔疾病防治

@#Crown pulp regeneration is a method to replace the pulp-capping agent with stem cells and scaffold structures, which are placed on the section of healthy root pulp tissue after pulpotomy to regenerate the pulp-dentin complex in the crown. This paper reviews the significance, physiological basis, application and challenges of crown pulp regeneration to provide new ideas for the study of pulp regeneration. The results of a literature review show that the combination of traditional pulpotomy, stem cell biology and tissue engineering, as well as the regeneration of crowns and pulp by using the tissue repair potential of healthy root pulp can effectively promote the regeneration of dentin and parts of pulp. In recent years, with the development of research on pulp regeneration, many challenges have been gradually revealed. It is necessary not only to select the treatment methods that can promote the proliferation and differentiation of dental pulp stem cells safely and effectively but also to continue to explore the scaffold materials suitable for the structural and functional diversity of the pulp chamber.

Preparation of polydopamine coated 3D printed biphasic calcium phosphate tissue engineering scaffold and its evaluation / 吉林大学学报(医学版)

Objective: To coat polydopamine (PDA) on the surface of biphasic calcium phosphate (BCP) scaffold prepared by 3D printing and construct a novel bone tissue engineering scaffold with high osteogenic activity, and to conduct a preliminary evaluation on its application potential.Methods:BCP bioceramic scaffolds were prepared by 3D printing technology, and then they were immersed in dopamine solution for a certain period to form a nanoscale PDA film structure on the surface.The PDA-free scaffolds were named 3DBCP group, and the PDA-coated scaffolds were named PDA-3DBCP group. Scanning electron microscope (SEM) was used to observe the surface topography of the scaffolds in each group; the hydrophilicity of the material was characterized by measuring the water contact angle of the scaffold surface; the scaffold porosity was determined by the specific gravity method, and the mechanical strength was tested by the universal testing machine; CCK-8 assay was adopted to detect the cell proliferation activity on the scaffold.Results:Compared with 3DBCP group, the surface water contact angle of the the scaffolds in PDA-3DBCP group was significantly reduced (t=5.06,P0.05;t=0.002,P>0.05).The cells were inoculated into the scaffolds and cultured for 1, 3 and 5 d;the CCK-8 assay results showed that the proliferation activities of the cells in two groups were gradually increased with the prolongation of the culture time. Furthermore, compared with 3DBCP group, the cell proliferation activity of the cells in PDA-3DBCP group on the 5th day was significantly increased (t=39.3,P<0.05).Conclusion: The PDA-coated 3D printed BCP porous scaffold has the advantages in characterization,it can improve the cell proliferation ability, which shows the potential as bone tissue engineering scaffolds.

Minimally invasive treatment for osteonecrosis of the femoral head in ARCO stage Ⅱ and Ⅲ with bioceramic system / 中国修复重建外科杂志

Objective: To perfect the theory system of minimally invasive treatment for osteonecrosis of the femoral head (ONFH) with β tricalcium phosphate (β-TCP) bioceramic system and evaluate the effectiveness. Methods: Eighteen New Zealand white rabbits aged 7-8 months were used to establish an animal model to verify the vascularization of porous β-TCP bioceramic rods. Micro-CT based three-dimensional reconstruction and fluorescence imaging were used to display the new blood vessels at 4, 8, and 12 weeks after operation. The inserting depth, number and diameter of vessels in the encapsulated area were analyzed. Nine pig femoral specimens were randomly divided into 3 groups ( n=3): group A was normal femur; group B had cavity (core decompression channel+spherical bone defect in femoral head); in group C, mixed bioceramic granules were implanted to fill the defect in femoral head, and porous β-TCP bioceramic rod was implanted into decompression channel. The stiffness and yield load of specimens were analyzed by biomechanical test. A multicenter retrospective study was conducted to analyze 200 patients (232 hips) with femoral head necrosis treated with bioceramic system in 7 hospitals in China between January 2012 and July 2018. There were 145 males and 55 females, with an average age of 42 years (range, 17-76 years). According to the Association Research Circulation Osseous (ARCO) stage, 150 hips were in stage Ⅱ and 82 hips in stage Ⅲ. Postoperative imaging assessment was carried out regularly, and hip function was evaluated by Harris score. The effectiveness of ARCO stage Ⅱ and Ⅲ was also compared. Results: Animal experiments showed that blood vessels could grow into the encapsulated area and penetrate it at 12 weeks. The inserting depth, number and diameter of blood vessels in the encapsulated area gradually increased, and there was significant difference between different time points ( P<0.05). Biomechanical tests showed that the stiffness and yield load of specimens in groups B and C were significantly lower than those in group A, while the yield load in group B were significantly lower than that in group C ( P<0.05). The stiffness in group C was restored to 41.52%±3.96% in group A, and the yield load was restored to 46.14%±7.85%. Clinical study showed that 200 patients were followed up 6-73 months, with an average of 22.7 months. At last follow-up, 12 patients (16 hips) underwent total hip arthroplasty, and the hip survival rate was 93.10%. According to the imaging evaluation, 184 hips (79.31%) were stable and 48 (20.69%) were worse. Harris score (79.3±17.3) was significantly higher than that before operation (57.3±12.0) ( t=18.600, P=0.000). The excellent rate of hip function was 64.22% (149/232). The survival rate of hip joint, imaging score and Harris score of patients in ARCO stage Ⅱ were better than those in ARCO stage Ⅲ ( P<0.05). Conclusion: β-TCP bioceramic system can guide the abundant blood supply of greater trochanter and femoral neck to the femoral head to promote repair; it can partly restore the mechanical properties of the femoral head and neck in the early stage, providing a new minimally invasive hip-preserving method for patients with ONFH, especially for those in early stage.

Análise de sistemas reciprocantes quanto a produção de desvios e remoção de material obturador em canais radiculares: estudo in vitro / Analysis of reciprocal systems regarding the production of deviations and removal of filling material in root canals: in vitro study

O retratamento endodôntico é um procedimento realizado quando o tratamento anterior tem insucesso e visa reverter os processos infecciosos, removendo completamente o material obturador permitindo uma nova limpeza, modelagem e reobturação dos canais radiculares. Com vistas a melhoria das taxas de sucesso e eficiência do retratamento, vários sistemas de níquel-titânio (NiTi) têm sido desenvolvidos com a utilização de apenas um instrumento por meio de um movimento reciprocante, levantado novas perspectivas para o preparo biomecânico do canal radicular, bem como, o retratamento. Portanto, este estudo teve por objetivo analisar a produção de desvio e capacidade de limpeza durante retratamento dos canais mesiais de molares inferiores com curvaturas severas (30° e 70°), obturados com BioC Sealer após utilização dos sistemas reciprocantes. Uma amostra de sessenta molares inferiores foi dividida em quatro grupos experimentais, assim distribuídos: G1- X1-Blue (25.06); G2- WaveOne Gold Primary (25.07); G3- Reciproc Blue (25.08); G4- WA1 (25.07). Cada grupo continha 15 molares, totalizando 120 canais mesiais, os quais passaram pela aquisição e processamento das imagens iniciais no Microtomográfo, para que posteriormente, fosse realizado o pareamento dos grupos. Todos os grupos foram instrumentados com o sistema de rotação continua Pro Taper Next. Após instrumentação, foram obturados com cone de guta percha ProTaper Universal, selados e colocados em estufa a 37 °C, 100% de umidade durante 72 horas. Para análise de desvio e remoção da obturação dos canais as amostras foram escaneadas por meio da Microtomografia (MicroCT). Por fim, foi avaliado e medido o desvio apical através da comparação das imagens dos canais obtidas pelas Micro-CT após o retratamento, bem como a remoção do material obturador, para posterior análise estatística. Os resultados quanto a produção de desvio após remoção do material obturador, entre grupos, demonstrou não haver diferença estatisticamente significante tanto para os canais radiculares mesio vestibulares como para os canais mesio linguais (p > 0,05). Na análise intra grupo, não houve diferença em relação aos grupos G1(X1 Blue), G2 (Wave one Gold) e G3 (Reciproc Blue) (p > 0,05), porém o grupo G4 (WA1) apresentou diferença significante, mostrando maior grau de desvio no canal mesio lingual do que no mesio vestibular (p < 0,05). Com relação a remoção do material obturado, na análise entre grupo, para o canal Mesio vestibular, pode-se observar que em todos os grupos houve uma diminuição no sentido cervical para apical, porém, no grupo G4 (WA1) observou-se uma maior remoção tanto no terço médio quanto no apical. No terço cervical a maior remoção do material obturador ocorreu no grupo G2 (Wave one Gold), seguido do G4 (WA1), G3 (Reciproc Blue) e G1(X1 Blue). Para o canal mesio lingual, o grupo G4 (WA1) demonstrou uma maior estabilidade de remoção do material obturador em todos os terços. No terço cervical houve uma maior remoção do material obturador no grupo G2, seguido do G4, G3 e G1, já no terço médio foi no grupo G2, seguido do G1, G4 e G3. No terço apical, o grupo G4 promoveu maior capacidade de remoção de material obturador, seguido de G1, G2 e G3. Para comparação entre médias intragrupos, não houve diferença estatisticamente significante quando se comparou os terços cervical/médio para os Grupos G1 e G4 (tanto no canal Mesio vestibular como no mesio lingual) e terços médio/apical (apenas no canal Mesio lingual), porém, o terço apical foi observado uma maior dificuldade na remoção do material obturador. Conclui-se que a maiorias dos sistemas reciprocantes testados no retratamento promoveram desvio apical, porém o sistema WA1 foi capaz de produzir menos desvio no canal Mesio vestibular. Os sistemas reciprocantes utilizados foram capazes de remove grande parte do material obturador, mas não em sua totalidade, o terço apical foi o que mais dificultou a remoção do material obturador, porém, o sistema WA1 foi o que apresentou maior desempenho neste terço (AU).

Endodontic retreatment is a procedure performed when the previous treatment is unsuccessful and aims to reverse infectious processes, completely removing the shutter material allowing a new cleaning, modeling and reobturation of root canals. With a view to improving success rates and retreatment efficiency, several nickel-titanium (NiTi) systems have been developed with the use of only one instrument through a reciprocal movement, raising new perspectives for biomechanical preparation of the root canal, as well as retreatment. Therefore, this study aimed to analyze the production of deviation and cleaning capacity during retreatment of the mesiaal channels of lower molars with severe curvatures (30° and 70°), obtained with BioC Sealer after using reciprocating systems. A sample of sixty lower molars was divided into four experimental groups, thus distributed: G1- X1-Blue (25.06); G2- WaveOne Gold Primary (25.07); G3- Reciproc Blue (25.08); G4- WA1 (25.07). Each group contained 15 molars, totaling 120 mesiaal channels, which passed through the acquisition and processing of the initial images in the Microtomográfo, so that later, the pairing of the groups was performed. All groups have been instrumented with the continuous Rotation System Pro Taper Next. After instrumentation, they were filled with protaper universal percha gutcone, sealed and placed in a greenhouse at 37 °C, 100% humidity for 72 hours. For analysis of deviation and removal of the filling of the channels, the samples were scanned by microtomography (Micro-CT). Finally, apical deviation was evaluated and measured by comparing the images of the channels obtained by micro-CT after retreatment, as well as removal of the shutter material, for further statistical analysis. The results regarding the production of deviation after removal of the shutter material between groups, showed no statistically significant difference both for vestibular mesium root canals and for lingual mesio channels (p > 0.05). In the intra-group analysis, there was no difference in relation to groups G1(X1 Blue), G2 (Wave one Gold) and G3 (Reciproc Blue) (p > 0.05), but group G4 (WA1) showed a significant difference, showing a higher degree of deviation in the lingual mesium channel than in the vestibular mesium (p < 0.05). Regarding the removal of the obtained material, in the analysis between group, for the vestibular Mesio canal, it can be observed that in all groups there was a decrease in the cervical direction to apical, however, in group G4 (WA1) there was a greater removal in both the middle and apical third. In the cervical third the highest removal of the shutter material occurred in group G2 (Wave one Gold), followed by G4 (WA1), G3 (Reciproc Blue) and G1 (X1 Blue). For the lingual mesio channel, group G4 (WA1) demonstrated greater shutter material removal stability across all thirds. In the cervical third, there was a higher removal of the shutter material in group G2, followed by G4, G3 and G1, already in the middle third it was in group G2, followed by G1, G4 and G3. In the apical third, group G4 promoted higher shutter material removal capacity, followed by G1, G2 and G3. For comparison between intragroup means, there was no statistically significant difference when comparing the cervical/middle thirds for Groups G1 and G4 (both in the vestibular mesio channel and in the lingual mesium) and middle/apical thirds (only in the lingual Mesio canal), however, the apical third was observed a greater difficulty in removing the shutter material. It was concluded that most of the reciprocal systems tested in the retreatment promoted apical deviation, but the WA1 system was able to produce less deviation in the vestibular Mesio canal. The reciprocal systems used were able to remove much of the shutter material, but not in its entirety, the apical third was the one that most difficult to remove the shutter material, however, the WA1 system was the one that performed higher in this third (AU).

Retreatment Efficacy of Endodontic Bioceramic Sealers: A Review of the Literature / Eficacia del retratamiento de cementos endodónticos biocerámicos: Revisión de Literatura

Abstract The endodontic retreatment is a feasible solution when post-operative apical periodontitis persists or develops. The complete removal of the filling materials is important in order to ensure the unobstructed contact of the intracanal disinfectants with the microbes. As a new generation of bioceramic endodontic sealers has emerged, their removal efficacy from the root canal system during retreatment is a matter of concern among clinicians. The aim of this article is to provide a comprehensive review of the current literature on the retreatability of these novel obturating materials. A significant amount of bioceramic sealer remnants in the root canal walls was observed in all studies. Even though canal cleanliness could not be obtained at an ideal level, the re-establishment of the working length and patency can be considered manageable and comparable to other endodontic sealers.

Resumen El retratamiento endodóntico es una solución factible cuando la periodontitis apical post-operatoria persiste o se desarrolla. La eliminación completa de los materiales obturadores es importante para garantizar el contacto y acción de los desinfectantes e irrigantes endodónticos con los microorganismos persistentes. A medida que ha surgido una nueva generación de selladores endodónticos biocerámicos, su eficacia de eliminación del sistema de conductos radiculares durante el retratamiento es motivo de preocupación entre los profesionales. El objetivo de este artículo es proporcionar una revisión exhaustiva de la literatura actual sobre la influencia o posibles limitantes del uso de este tipo de cementos bioactivos durante el retratamiento endodóntico. Los estudios determinaron una cantidad significativa de restos de selladores biocerámicos en las paredes del conducto radicular. Aunque la limpieza del canal no se pudo obtener a un nivel "ideal", el restablecimiento de la longitud de trabajo y la permeabilidad se puede considerar manejable y comparable a otros selladores endodónticos.

Evaluation of Microleakage by Gas Permeability and Marginal Adaptation of MTA and BiodentineTM Apical Plugs: In Vitro Study / Evaluación de la microfiltración por permeabilidad de gas y adaptación marginal de tapones apicales de MTA y BiodentineTM: Estudio in vitro

Abstract The endodontic treatment of teeth with incomplete development is always a complex task. Nowadays, biomaterials such as bioceramics offers promising clinical evidence that supports its use. However, the standardization of its use for apexification purpose still needs a deeper understanding of the materials' behavior. The aim of this investigation was to evaluate the marginal adaptability and microleakage by gas permeability of MTA and Biodentine™ apical plugs in an in vitro model. Materials and methods: Twenty- four single rooted human teeth were selected according to previously stablished inclusion criteria. All samples were prepared obtaining standard cylindrical internal canals with a diameter of 1.3 mm. Root canals were gently rinsed using 5.25% sodium hypochlorite and EDTA 17%. The apical 3mm and remaining coronal dental structure were sectioned to obtain 10mm roots. Roots were randomly assigned to 3 different groups as follows: GROUP A: MTA (n=10), GROUP B: Biodentine™ (n=10) and Group C: Control (positive n=1, negative n=3). MTA and Biodentine™ were prepared according to manufacturer's indications, and apical plugs of 4mm were passively placed in the correspondent teeth. All samples were stored in saline solution for 7 days at 37°C before evaluation. Samples were mounted in cylindrical sample-holders using epoxy resin. Microleakage was evaluated with an automatic permeability detector that calculates nitrogen diffusion between the material-root interphase. After microleakage evaluation, the samples were recovered and analyzed by scanning electron microscopy (SEM). Microleakage results were analyzed using Chi-square and adaptation was evaluated with a descriptive analysis. Results: None of the evaluated materials completely avoided the nitrogen microleakage (positive leakage of 10% and 20% of samples for MTA and Biodentine™ respectively); with no statistical significant difference between groups (p=0.527). All apical plugs showed good adaptation under SEM, at 30x, 200x, 1000x and 2500x; with microscopical structures similar to previous reports. Conclusions: Both bioceramics behave similar when used as apical barriers to avoid permeability, with acceptable marginal adaptation. Further in vivo studies are needed to validate these results.

Resumen El tratamiento endodóntico de dientes con desarrollo incompleto es siempre una tarea compleja. Hoy en día, biomateriales como las biocerámicas ofrecen una evidencia clínica prometedora que apoya su uso. Sin embargo, la estandarización de su uso para fines de apexificación todavía necesita una comprensión más profunda del comportamiento de los materiales. El objetivo de esta investigación fue evaluar la adaptabilidad marginal y microfiltración por permeabilidad de gas de los tapones apicales de MTA y Biodentine™ en un modelo in vitro. Materiales y métodos: Veiticuatro dientes humanos uniradiculares fueron seleccionados meticulosamente según criterios de inclusión previamente establecidos. Todas las muestras fueron preparadas con canales cilíndricos internos estandarizados de 1,3 mm de diámetro. Los conductos radiculares fueron gentilmente lavados con hipoclorito de sodio al 5,25% y EDTA al 17%. La estructura dental apical de 3 mm y la coronal restante se seccionó para obtener raíces de 10 mm de longitud. Las raíces se asignaron aleatoriamente a 3 grupos diferentes de la siguiente manera: GRUPO A: MTA (n = 10), GRUPO B: Biodentine™ (n = 10) y Grupo C: Control (n = 1 positivo, n = 3 negativos). El MTA y Biodentine™ se prepararon de acuerdo con las indicaciones de los fabricantes, y se colocaron pasivamente los tapones apicales de 4 mm en los dientes correspondientes. Todas las muestras se almacenaron en solución salina durante 7 días a 37ºC antes de la evaluación. Las muestras se montaron en porta-muestras cilíndricos utilizando resina epóxica. La microfiltración se evaluó con un detector de permeabilidad automática que calcula la difusión de nitrógeno entre la interfase material-raíz. Después de la evaluación de microfiltración, las muestras fueron recuperadas y analizadas por microscopía electrónica de barrido (SEM). Los resultados de microfiltración se analizaron utilizando una prueba estadística de Chi-cuadrado y la adaptación se evaluó con un análisis descriptivo. Resultados: Ninguno de los materiales evaluados evitó completamente la microfiltración de nitrógeno (fuga positiva de 10% y 20% de muestras para MTA y Biodentine™, respectivamente); sin diferencias estadísticamente significativas entre los grupos (p = 0,527). Todos los tapones apicales mostraron una buena adaptación bajo SEM, a 30x, 200x, 1000x y 2500x; con morfologías similares a las previamente reportadas. Conclusiones: ambas biocerámicas se comportan de forma similar cuando se usan como barreras apicales para evitar la permeabilidad de gas, con adaptación marginal aceptable. Se necesitan más estudios in vivo para validar estos resultados.

Biocerâmica de fosfato de cálcio nanoestruturada micro-macroporosa em grânulos de absorção rápida no preenchimento de defeito crítico em rádio de coelhos (Oryctolagus cuniculus) / Bioceramics of calcium phosphate nano-structured micro-macro porous granules rapidly absorbed in filling critical radial defect in rabbits (Oryctolagus cuniculus)

O objetivo do presente trabalho foi avaliar, por radiografia, histologia e densitometria óssea, o efeito da HA/ßTCP em grânulos de absorção rápida em defeito ósseo crítico em rádio de coelhos. Foram utilizados 35 coelhos machos, da raça Nova Zelândia, e realizou-se um defeito crítico nos rádios direito e esquerdo. Os animais foram distribuídos em GI, enxerto autólogo e GII, HA/ßTCP em grânulos de absorção rápida. Avaliações radiográficas foram feitas antes da cirurgia, após, aos oito, 15, 30, 45 e 60 dias e avaliações histológicas e de densitometria. Verificou-se diferença significativa ao se comparar a densidade mineral óssea obtida ao longo do tempo de estudo. Observou-se formação de rede vascular entre os poros da biocerâmica desde o primeiro tempo de avaliação, (oito dias). Foram observados tecido ósseo primário e trabéculas em tecido ósseo preexistente a partir de 30 dias da implantação. Aos 60 dias, constatou-se presença de matriz óssea em segmentos ósseos preexistentes, caracterizando a formação óssea centrípeta. A biocerâmica HA/ßTCP nanoestruturada micro-macroporosa em grânulos de absorção rápida não causa alterações microscópicas indicativas de rejeição, permite a invasão e a multiplicação celular, bem como propicia a regeneração óssea, constituindo um implante apropriado para preenchimento de falhas ósseas críticas.(AU)

The objective of this study was to evaluate the effect of HA/ ßTCP on rapid absorption granules in rabbit radiography, histology, and bone densitometry. Thirty - five male rabbits of the New Zealand breed were used and a critical defect was performed on the right and left radios. The animals were distributed in GI, autologous graft and GII HA / ßTCP in rapidly absorbed granules. Radiographic, histological, and densitometry evaluations were performed before surgery, then after eight, 15, 30, 45 and 60 days. A significant difference was found when comparing the bone mineral density obtained over the study time. Formation of vascular network between the bioceramic pores was observed by the first evaluation time, (eight days). Primary bone tissue and trabeculae were observed from preexisting bone tissue after 30 days of implantation. At 60 days, the presence of bone matrix was observed from the preexisting bone segments, characterizing the centripetal bone formation. The micro-macroporous nanocomposite HA / ßTCP of rapidly absorbing granules do not cause microscopic changes indicative of rejection, allows invasion, cell multiplication, and promotes bone regeneration, constituting an appropriate implant for filling of critical bone failures.(AU)

Surface roughness and volumetric contraction of a Y-TZP ceramic sintered by microwave energy and by resistive heating / Rugosidade da superfície e contração volumétrica de uma cerâmica Y-TZP sinterizada por energia de microondas e por aquecimento resistivo

Objectives: The aim of this study was to evaluate a Y-TZP ceramic sintered by a microwave protocol on volume shrinkage and surface roughness. Material and Methods: Twenty four (N=24) Y-TZP discs were fabricated by milling in CAD/ CAM for size standardization. The mean final dimensions of the specimens were 15 mm X 1.6 mm. Samples were divided into 2 groups (n=12): conventional resistive heating sintering protocol (C - Control) and microwave sintering protocol (MO - experimental). For the characterization of the specimens, surface roughness (Ra and Rz parameters) was evaluated with a roughness tester, and volume shrinkage was measured with a hand micrometer. Data were statistically evaluated by Student's t and Mann-Whitney U tests (α=0.05). Results: The roughness results were: 0.25 µm ± 0.02 (Ra) and 2.68 µm ± 0.666 (Rz) for the MO samples; 0.26 µm ± 0.04 (Ra) and 2.73 µm ± 0.461 (Rz) for the C group (Ra: p = 0.19; Rz: p = 0.81). The shrinkage results was: MO (21.02% ± 2.70) and C (20.10% ± 0.52) (p = 0.274). Conclusion: The conventional and microwave sintering methods were similar regarding surface roughness and volume shrinkage of Y-TZP dental ceramic (AU)

Objetivo: avaliar uma cerâmica de zircônia estabilizada com óxido de ítrio (Y-TZP) sinterizada por um protocolo em micro-ondas quanto à contração volumétrica e a rugosidade superficial. Material e Métodos: Vinte e quatro discos (n = 24) de Y-TZP foram fresados em CAD / CAM para padronização do tamanho. A dimensões finais médias dos corpos de prova foram de 15 mm X 1,6 mm. As amostras foram divididas em 2 grupos (n = 12): protocolo de sinterização convencional por aquecimento resistivo (C - Controle) e protocolo de sinterização por microondas (MO - experimental). A caracterização das amostras foi realizada pela avaliação da rugosidade superficial, com um rugosímetro (parâmetros Ra e Rz) e da contração volumétrica, medida com um micrômetro manual. Os dados foram estatisticamente avaliados pelos testes de t-Studant e U-Mann-Whitney (α=0,05). Resultados: Os resultados de rugosidade foram: 0,25 µm ± 0,02 (Ra) e 2,68 µm ± 0,666 (Rz) para o MO; e 0,26 µm ± 0,04 (Ra) e 2,73 µm ± 0,461 (Rz) para o grupo C (Ra: p = 0,19; Rz: p = 0,81). A contração volumétrica foi de: MO (21,02% ± 2,70) e C (20,10% ± 0,52) (p = 0,274). Conclusão: os métodos de sinterização convencionais e de microondas são semelhantes, no que diz respeito à rugosidade superficial e retração de volume da cerâmica dental Y-TZP. (AU)

Tapón apical con biocerámicos: tratamiento del ápice abierto en una cita

El trauma dental es una causa frecuente de necrosis pulpar en piezas anteriores, a edades tempranas, lo que detiene el desarrollo radicular y complica el manejo del caso. La apexificación con hidróxido de calcio ha sido el tratamiento de elección durante muchos años; sin embargo, requiere de muchas citas y se ha informado que su uso a largo plazo puede debilitar las paredes dentinales. Con el surgimiento de los materiales a base de biocerámicos, es posible realizar este tipo de tratamiento en una sola sesión y con resultados más predecibles. Por lo tanto, el objetivo de este artículo es mostrar el manejo de la apexificación en una cita mediante la creación de un tapón apical con MTA y su seguimiento a 4 años.

Dental trauma is a frequent cause of pulp necrosis in anterior teeth, at an early age, which stops root development and complicates case management. Apexification with calcium hydroxide has been the treatment of choice for many years, however, it requires many appointments and it has been reported that its long-term use can weaken the dentinal walls. With the emergence of materials based on bioceramics, it is possible to perform this type of treatment in a single session and with more predictable results. Therefore, the objective of this article is to show the management of the apexification in an appointment by creating an apical plug with MTA and its follow up to 4 years.

Synthesis and characterization of calcium phosphate compounds with strontium and magnesium ionic substitutions / Síntetis y caracterización del compuestos de fosfato de calcio con substituto iónico de estroncio y magnesio

Bioceramics offer advantages in the repair and regeneration of hard tissues and are used as bone void fillers and particulate fillers in bone cements with surgical applications. Regeneration and osteosynthesis stimulation via the release of essential ions such as strontium (Sr2+) and magnesium (Mg2+) is a relatively new field. Therefore, there is great interest in investigating various ionic substitutions on crystallographic structure and characteristics for use in osteoporosis prevent and increase bone formation and decrease bone resorption. In this study, we synthesize calcium phosphate samples with Sr2+ and Mg2+ ionic substitutions. The samples are characterized using X-ray diffraction, Fourier transform infrared spectroscopy, and inductively coupled plasma mass spectroscopy. Hydroxyapatite, beta tricalcium phosphate, and amorphous phases were observed. Depending on the ionic substitution, the crystal size and crystallinity varied from 22 nm to 130 nm and from 84% to 99.6%, respectively. The Ca/P ratio ranged from 0.72 to 1.82. The results demonstrated the effect of Sr2+ and Mg2+ inclusions in calcium phosphate on important parameters used in several bioceramic applications.

Los biocerámicos ofrecen ventajas en la reparación y regeneración de tejidos duros utilizándose como relleno en cavidades óseas y como relleno particulado en cementos óseos de aplicaciones quirúrgicas. Regeneración y estimulación de la osteosíntesis a través de la liberación de iones esenciales, como el estroncio (Sr) y magnesio (Mg) es un campo relativamente nuevo. Por lo tanto, existe un gran interés en la investigación de diversas sustituciones iónicos sobre la estructura cristalográfica y las características para su uso en la prevención de osteoporosis y aumento de la formación ósea con disminuir la resorción ósea. En este estudio, se sintetizó muestras de fosfato de calcio con sustituciones iónicos Sr y Mg. Las muestras se caracterizaron usando difracción de rayos X, espectroscopia infrarroja por transformada de Fourier, y la espectroscopia de masas con plasma acoplado inductivamente. Se observó hidroxiapatita, fosfato tricálcico beta, y las fases amorfas. Dependiendo de la sustitución iónica, el tamaño del cristal y cristalinidad variaron de 22 nm a 130 nm y de 84% a 99,6%, respectivamente. La relación Ca/P varió desde 0,72 hasta 1,82. Los resultados demostraron el efecto de las inclusiones de Sr y Mg en fosfato de calcio en parámetros importantes que se utilizan en varias aplicaciones de biocerámicos.

Observation on 5-year effect of porous calcium phosphate bioceramics for treating stage FicatⅢ non-traumatic osteonecrosis of femoral head in patients aged below 60 years old / 重庆医学

Objective To investigate the clinical efficacy of porous calcium phosphate bioceramics (PTCP)for treating stage FicatⅢ non-traumatic osteonecrosis of the femoral head(ONFH)in the patients aged below 60 years old.Methods A total of 41 patients (63 hips)with non-traumatic ONFH in our hospital from March 2006 to July 2009 were collected and divided into two groups.The group A (n=1 6)was performed the core decompression only,while the group B (n=25)was performed the core de-compression plus through the head-neck junction of the femur to opening the window light bulb shape focus debridement and impac-ting bone grafting combined with PTCP implantation.The various clinical evaluation indicators were observed and evaluated.Results No statistically significant differences in PRI were found at each time point in the group A.PRI at postoperative 1 month in the group B was significantly decreased than before operation,hereafter,the stable status was maintained and slightly risen again until postoperative 3 years(P =0.033).The Harris scores at postoperative all time points in the group A were significantly lower than those in the group B.The necrosis areas at postoperative 24 months,3,4,5 years in the group B were significantly decreased com-pared with before operation and lower than those in the group A.Conclusion PTCP implantation has satisfactory effect for the treatment of stage FicatⅢ non-traumatic ONFH in the patients aged below 60 years old.

Hard tissue regeneration using bone substitutes: an update on innovations in materials

Bone is a unique organ composed of mineralized hard tissue, unlike any other body part. The unique manner in which bone can constantly undergo self-remodeling has created interesting clinical approaches to the healing of damaged bone. Healing of large bone defects is achieved using implant materials that gradually integrate with the body after healing is completed. Such strategies require a multidisciplinary approach by material scientists, biological scientists, and clinicians. Development of materials for bone healing and exploration of the interactions thereof with the body are active research areas. In this review, we explore ongoing developments in the creation of materials for regenerating hard tissues.

Evaluación Clínica y radiográfica de injertos biocerámicos tipo Hidroxiapatita como alternativa en la reconstrucción de alveolos dentarios postexodoncia / Clinical and radiographic evaluation of grafts biocerámicos type Hidroxiapatita like alternative in the reconstruction of alveoli toothworts postexodoncia

Evaluar el comportamiento de la cresta ósea marginal con la plataforma del implante como referencia, en casos de pacientes con injerto aloplástico de la casa farmacéutica Madrob®con el fin de mantener la integridad ósea como elemento fundamental en la colocación de implantes dentales. Materiales y métodos: Se llevó a cabo un estudio de tipo comparativo y prospectivo, con una muestra intencional de 30 pacientes para un total de 81 implantes con previo requisito de injerto aloplásticos en alveolos pos exodoncia y posterior implante dental. Se realizaron controles clínicos y radiográficos a los 3, 6, 9, 12, 24 y 36 meses para evaluar el comportamiento de la cresta ósea marginal. Resultados: Hay mayor aumento de pérdida ósea por mesial que por distal entre los 12 y 36 meses. Entre 24 y 36 meses, el aumento es igual por mesial que por distal y es de solo 0,05mm. Las diferencias entre tiempos son todas significativas p<0,001. El ANOVA indica que todas las varianzas son homogéneas y pequeñas entre 0,18mm y 0,22mm...

This work is aimed at evaluating the response of the marginal bone crest using the implant's platform as a reference. The study considered patients with alloplastic grafts from Madrob® to establish the role of bone integrity in locating dental implants. Materials and Methods: The benchmark and prospective studies were conducted on 30 subjects .A total of 81 alveoli alloplastic implants were analyzed post-exodontia. The response of the marginal bone crest was evaluated after 3, 6, 9, 12, 24 and 36 months via clinical and radiographic controls Results: For the period between 12 and 36 months, mesial prevailed over distal bone loss. Mesial and distal gains of about 0,05 mm were equally important for the period between 24 and 36 months. p-values less than 0,001 indicate that differences between times are all significant. The ANOVA indicates that all the variances are homogeneous and small between 0,18mm and 0,22mm...