Paulo Hemerson de Moraes

Bacterial adhesion and colonization differences between zirconia and titanium implant abutments: an in vivo human study

Purpose Several parameters have been described for determining the success or failure of dental implants. The surface properties of transgingival implant components have had a great impact on the long-term success of dental implants. The purpose of this study was to compare the tendency of two periodontal pathogens to adhere to and colonize zirconia abutments and titanium alloys both in hard surfaces and soft tissues. Methods Twelve patients participated in this study. Three months after implant placement, the abutments were connected. Five weeks following the abutment connections, the abutments were removed, probing depth measurements were recorded, and gingival biopsies were performed. The abutments and gingival biopsies taken from the buccal gingiva were analyzed using real-time polymerase chain reaction to compare the DNA copy numbers of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and total bacteria. The surface free energy of the abutments was calculated using the sessile water drop method before replacement. Data analyses used the Mann Whitney U-test, and P-values below 0.05 find statistical significance. Results The present study showed no statistically significant differences between the DNA copy numbers of A. actinomycetemcomitans, P. gingivalis, and total bacteria for both the titanium and zirconia abutments and the biopsies taken from their buccal gingiva. The differences between the free surface energy of the abutments had no influence on the microbiological findings. Conclusions Zirconia surfaces have comparable properties to titanium alloy surfaces and may be suitable and safe materials for the long-term success of dental implants.

Condylar Resorption After Orthognathic Surgery: A Systematic Review

The aim of this research was to evaluate the risk factors related to condylar resorption (CR) after orthognathic surgery. Was realized a systematic review with a search of the literature performed in the electronic databases PubMed, MedLine, Ovid, Cochrane Library for current evidence in the world literature as conducted, and relevant articles were selected in according to inclusion and exclusion criteria and the findings were compared. Eight papers, (follow-up 12 months to 69 months) were including. A sample of 2567 patient with mandible or bi maxillary surgery with an age range from 14 to 46 year old was observed. In 137 patients (5.3%) CR was observed, with a 97.6% (122) female. CR was related to 118 cases with mandibular deficiencies with high mandibular plane (advancement surgery). CR were present principally in bi maxillary surgery with a 103 cases (75.2%) and only two papers show any analysis to the relation with TMJ dysfunction. Current evidence in CR is poor but supports those female patients with mandibular deficiency and high mandibular plane angle submitted to bi maxillary surgery with change in occlusal plane (counterclockwise) are associated with condylar resorption after orthognathic surgery.

Anatomical Reproducibility through 3D Printing in Cranio-Maxillo-Facial Defects

La planificacion y reconstruccion 3D en defectos craneofaciales se basa en principios anatomicos de simetria y pasividad en la adaptacion, evolucionando rapidamente en los ultimos anos. El presente articulo presenta la posibilidad de rehabilitacion de un paciente con trauma importante gracias a un implante craneofacial extenso. Se presenta el caso de un sujeto con evolucion de 10 anos de una secuela de trauma, donde perdio el hueso frontal, pared supraorbitaria y parte de la fosa temporal. A partir de una tomografia computadorizada, utilizando un software de planificacion Materialise (3-Matic and Mimics) se construyo un modelo virtual a traves de un implante de pieza unica para cubrir integramente el defecto; se planifico la posicion junto a la cantidad y longitud de tornillos a utilizar. A continuacion se realizo la impresion de la pieza mediante una impresora laser de titanio donde la pieza fue construida segun las especificaciones de la planificacion; la cirugia fue realizada sin complicaciones en el cual el implante fue instalado a traves de un acceso coronal sin necesidad de ningun tipo de adaptacion. Despues de dos anos de seguimiento se observa una posicion correcta, simetrica y en ausencia de infecciones u otro tipo de alteracion. Se concluye que la planificacion e impresion 3D es viable de realizar en reconstruccion craneofacial con baja morbilidad, disminucion del tiempo quirurgico, obteniendo una adecuada simetria y estetica facial.

Accuracy in the Diagnosis of the Mental Nerve Loop: A Comparative Study Between Panoramic Radiography and Cone Beam Computed Tomography

Dental implant and chin osteotomy are executed on the mandible body and the mental nerve is an important anatomical limit. The aim of this research was to know the position of the mental nerve loop comparing result in panoramic radiography and cone beam computed tomography. We analyzed 94 hemimandibles and the patient sample comprised female and male subjects of ages ranging from 18 to 52 years (mean age, 35 years) selected randomly from the database of patients at the Division of Oral Radiology at Piracicaba Dental School State University of Campinas; the anterior loop (AL) of the mental nerve was evaluated regarding the presence or absence, which was classified as rectilinear or curvilinear and measurement of its length was obtained. The observations were made in the digital panoramic radiography (PR) and the cone beam computed tomography (CBCT) according to a routine technique. The frequencies of the AL identified through PR and CBCT were different: in PR the loop was identified in 42.6% of cases, and only 12.8% were bilateral. In contrast, the AL was detected in 29.8% of the samples using CBCT, with 6.4% being bilateral; Statistical comparison between PR and CBCT showed that the PR led to false-positive diagnosis of the AL in this sample. According to the results of this study, the frequency of AL is low. Thus, it can be assumed that it is not a common condition in this population.

Estudio Morfométrico del Seno Maxilar Mediante Tomografías Computadorizadas: Evaluación de la Reconstrucción Total de Piso Sinusal

La rehabilitacion con implantes dentales en maxila posterior es compleja debido a la presencia del seno maxilar con sus diferentes variaciones anatomicas; el objetivo de este trabajo fue determinar el volumen oseo intrasinusal necesario para realizar la instalacion de uno o mas implantes dentarios sin invadir la membrana sinusal. En 22 craneos fueron evaluados 40 senos maxilares mediante tomografias computadorizadas (TC) realizando mediciones en los cortes axiales, coronales y sagitales. Se clasificaron los senos maxilares segun el remanente de hueso alveolar y se instalo un implante de forma virtual en el lugar del primer molar superior, mediante el software implant view. Con estas medidas volumetricas finales se establecio las indicaciones reconstructivas intra sinusales a partir de los sitios donantes intrabucales mas frecuentemente evaluados en la literatura mundial. El grupo I (1mm a 4mm de reborde alveolar remanente) presentaba deficit oseo de hasta 1,98cm3, el grupo II (4mm a 7mm) presentaba deficit de 1,06cm3; el grupo III (7mm a 10mm) presentaba un deficit de 0,67 cm3; a partir de estos resultados podemos concluir que los sitios intrabucales pueden ser utilizados en la mayoria de los grupo estudiados, incluyendo las reconstrucciones bilaterales.

Synthesis and Characterization of Calcium Phosphate Compounds with Strontium and Magnesium Ionic Substitutions

Los bioceramicos ofrecen ventajas en la reparacion y regeneracion de tejidos duros utilizandose como relleno en cavidades oseas y como relleno particulado en cementos oseos de aplicaciones quirurgicas. Regeneracion y estimulacion de la osteosintesis a traves de la liberacion de iones esenciales, como el estroncio (Sr) y magnesio (Mg) es un campo relativamente nuevo. Por lo tanto, existe un gran interes en la investigacion de diversas sustituciones ionicos sobre la estructura cristalografica y las caracteristicas para su uso en la prevencion de osteoporosis y aumento de la formacion osea con disminuir la resorcion osea. En este estudio, se sintetizo muestras de fosfato de calcio con sustituciones ionicos Sr y Mg. Las muestras se caracterizaron usando difraccion de rayos X, espectroscopia infrarroja por transformada de Fourier, y la espectroscopia de masas con plasma acoplado inductivamente. Se observo hidroxiapatita, fosfato tricalcico beta, y las fases amorfas. Dependiendo de la sustitucion ionica, el tamano del cristal y cristalinidad variaron de 22 nm a 130 nm y de 84% a 99,6%, respectivamente. La relacion Ca/P vario desde 0,72 hasta 1,82. Los resultados demostraron el efecto de las inclusiones de Sr y Mg en fosfato de calcio en parametros importantes que se utilizan en varias aplicaciones de bioceramicos.

Estudio Morfométrico de la Región Orbitaria para la Instalación de Implantes Craneofaciales

El objetivo de esta investigacion es establecer las relaciones morfometricas presentes en las regiones periorbitarias utilizadas para la instalacion de implantes craneofaciales. Se diseno un estudio descriptivo utilizando 40 craneos humanos de entre 20 y 60 anos del Laboratorio de Anatomia del Departamento de Morfologia de la Facultad de Odontologia de Piracicaba de la Universidad Estadual de Campinas. Fueron realizadas tomografias volumetricas cone beam y a partir de la reconstruccion virtual se precisaron los puntos de analisis, basados en la literatura cientifica, tanto clinica como anatomica de la region. Se realizaron divisiones de la orbita respetando distancias minimas y reparos anatomicos como el seno frontal y seno maxilar. En las mediciones realizadas, se observo que el area supraorbitaria presentaba una distancia osea sagital de 8,14mm ± 1,91mm, el reborde infraorbitario de 7mm ± 1,71mm y el area lateral de orbita un promedio de 7,91mm ± 1,15mm. Considerando que los implantes de mayor dimension son de 6mm, la instalacion de implantes en estas regiones esta totalmente asegurada en terminos de requerimientos de cantidad osea regional.

Maxillary Reconstruction Using rhBMP-2 and Titanium Mesh: Technical Note About the Use of Stereolithographic Model

La reconstruccion maxilar es un procedimiento comun en cirugia maxilofacial; para este proposito es utilizado hueso autogeno, hueso aloplastico u otro tipo de hueso con diferentes resultados. En todos ellos, tradicionalmente el uso de tomografia computadorizada se emplea para elaborar el plan quirurgico, sin embargo, los modelos 3D no son utilizados con frecuencia. Este reporte presenta una nueva aplicacion de la estereolitografia para anticipar el tratamiento quirurgico de la reconstruccion maxilar, usando una malla de titanio y rhBMP-2 para obtener un resultado quirurgico predecible con disminucion del tiempo quirurgico.

TMJ Total Joint Prosthesis for Condylar Fracture Malunion

In the international literatura exist some information related to temporomandibular joint (TMJ) involvement in condylar fracture malunion; the treatment is variated being executed with a bone reconstruction, ramus vertical osteotomy or condilar plate. This case demonstrates that TMJ replacement with prosthetic joint is technically possible and appropriate in the case of malunion of condylar fracture.

Custom-Made Titanium Miniplates Associated With Ultrahigh-Molecular-Weight Polyethylene Graft in Orthognathic Surgery: An Adjunct to Maxillary Advancement

Patients with considerable maxillomandibular anteroposterior discrepancies and maxillary hypoplasia require corrective treatment through orthognathic surgery. However, in the treatment of severe maxillary retrognathism, it is necessary to reconstruct areas of bone deficiency through grafting techniques in addition to maxillary advancement using only the Le Fort I osteotomy. Treatment in these patients is more challenging and requires high surgical predictability. Alloplastic materials often have been used for the reconstruction of poor bone contours. Ultrahigh-molecular-weight polyethylene (UHMWPE) is currently an excellent filler material for poor bone regions and is a good substitute for autografts and other alloplastic materials for its unique properties, including high biocompatibility. Insertion of this material in the fixation system customized for virtually planned orthognathic surgeries is an innovative technique. This report describes the insertion of UHMWPE into custom-made titanium miniplates manufactured by computer-aided design and computer-aided manufacturing technology for orthognathic surgery consisting of maxillary advancement and mandibular retrusion to treat a patient with Crouzon syndrome, Class III malocclusion, and severe maxillary retrognathism.