Revista de patología y medicina dental.

Abstracto

Odontología mundial 2019: Cerámica: Implantología y odontología restauradora - Shepard DeLong, Lotus Dental Wellness

Pastor DeLong

La producción de cerámica ha sido durante mucho tiempo una pieza fundamental e indispensable de la odontología terapéutica. Más recientemente, los aparatos de incrustación cocida, así como los nuevos materiales terapéuticos, brindan soluciones libres de metales, realistas y biocompatibles para las necesidades dentales de los pacientes. La cerámica, práctica e inmunológicamente estable, está ganando terreno en la odontología clínica y la cirugía. En general, solo una pequeña parte de los odontólogos, especialistas, científicos, expertos, fabricantes de incrustaciones y de incrustaciones están participando en este campo en crecimiento. En esta introducción, el Dr. DeLong compartirá sus propios informes de casos clínicos de progreso, la investigación detrás de la producción de cerámica disponible actualmente y una perspectiva hacia el futuro de la odontología sin metales.

El titanio es el material de mejor calidad para fabricar insertos dentales desde hace más de 30 años, lo que indica una alta tasa de éxito en diversas situaciones clínicas. Los insertos de zirconia se han familiarizado recientemente con algunos problemas estéticos y orgánicos que pueden surgir del titanio. Las investigaciones preclínicas muestran que, desde una perspectiva mecánica, la zirconia podría ser un sustituto adecuado del titanio en la fabricación de implantes. Los modelos de investigación de componentes limitados (FEA) tridimensionales no encontraron diferencias entre los insertos de titanio y los de compuestos de titanio-circonio, ni para el apilamiento funcional temprano ni tradicional. En general, la zirconia presenta las mismas propiedades osteoconductoras que el titanio, independientemente de que los dos estudios clínicos muestran tasas de resistencia y éxito algo mediocres para los insertos de zirconia en comparación con los de titanio, y faltan encuentros posteriores a largo plazo. Por lo tanto, la mayoría de los autores aceptan tener cuidado al proponer los insertos de zirconia como un sustituto de largo plazo de los insertos de titanio.

El titanio industrialmente puro (CP) es el material de mejor calidad utilizado para crear implantes dentales durante más de 30 años, demostrando una alta tasa de éxito en diversas situaciones clínicas.

Con el tiempo, los implantes de titanio pueden presentar algunos problemas estéticos: el tono oscuro del implante de titanio puede ser visible en el tejido periincrustado, lo que provoca problemas estéticos, especialmente en la zona anterior. Esta situación puede empeorar si se producen retracciones de la mucosa periincrustada con el tiempo. La disponibilidad de un implante "blanco" puede ser importante en aquellos casos clínicos en los que se requiere un resultado estético.

Moreover, titanium particles because of wear and consumption items might be discharged in tissues near inserts, and they were found in territorial lymph hubs. At times, this may prompt host response or sharpening. A few instances of hypersensitive response to titanium are archived, regardless of whether uncommon. In this way, utilizing some nonmetallic material as an option in contrast to the titanium embed might be valuable and, at times, basic. To wrap things up, in every case more patients demand totally sans metal prosthetic reproductions.

Artistic inserts were acquainted with overpower some stylish and organic issues that can emerge from titanium. The main fired dental embed was produced using alumina (i.e., aluminum oxide, Al2O3) somewhere in the range of 1960s and 1970s, and that was the main earthenware material utilized as of not long ago. Notwithstanding, alumina introduced some biomechanical issues (like low crack strength), and it was then totally surrendered and supplanted with zirconia that is these days the main elective clay material to titanium for dental inserts.

The point of this part is to survey the current writing with respect to zirconia dental inserts, featuring the solid focuses and focusing on the so far hazy angles.

Zirconia (zirconium dioxide, ZrO2) is a white crystalline oxide of zirconium. It is polymorphic in nature, changing its crystalline reticule from monoclinic (at room temperature) to tetragonal to cubic at expanding temperatures. By adding a few oxides to zirconia, it is conceivable to settle the tetragonal and additionally cubic stages. The alleged incompletely settled zirconia (PSZ) comprises for the most part of a cubic stage, with monoclinic and tetragonal zirconia as minor stages. By including 2–3% of yttria (yttrium oxide, Y2O3), it is conceivable to get a totally tetragonal zirconia, the purported yttria-balanced out tetragonal zirconia polycrystal (Y-TZP). The Y-TZP is the most performing zirconia from a mechanical perspective and the most utilized in dentistry to create inserts, embed projections and systems for crowns and extensions

It's intriguing and now and again exceptional mechanical properties are the reasons why zirconia is frequently called "clay steel": a high consumption and wear obstruction, high Young's modulus (200 GPa), a high flexural quality (up to 1200 MPa), a high crack durability and a polymorphic conduct [10]. The last is presumably the most intriguing viewpoint: zirconia may adjust the three-dimensional aura of the structure when some vitality is given, that is the thing that occurs in a split inception. In closeness of the split, the vitality changes the stage locally, diverting the reticule from tetragonal to monoclinic. This stage change occurs with an expansion in volume (3–4%): the development of the gems contradicts to break engendering and forestalls naturally visible disappointment, upgrading crack durability. This component is known as change toughening.

Such an incredible component of activity against split engendering has been addressed in view of the alleged low-temperature debasement process, a kind of maturing of zirconia. It appears that within the sight of water, the yttrium particles can be filtered, and their settling impact can be lost. All things considered, an unconstrained irreversible change from the metastable tetragonal stage to the stable monoclinic stage can happen on the outside of zirconia. Such a balanced out monoclinic stage doesn't have the limit any longer to modify the crystalline reticule thus to restrict to an approaching crack. Be that as it may, the effect of this issue on the drawn out clinical conduct of zirconia prosthetic segments and embeds is as yet muddled.

The biocompatibility of zirconia is entrenched from both in vitro and in vivo examinations. In-vitro tests were directed on different cell lines, for example, osteoblasts, fibroblasts, lymphocytes, monocytes, and macrophages, indicating no cytotoxic impacts. In vivo tests additionally demonstrated no cytotoxicity in delicate (connective) or hard (bone) tissues. Therefore, its utilization as a biomedical embed (e.g., in orthopedic medical procedure) is far reaching.

Thinking about the trouble of examining the mechanical result of inserts in clinical situations, preclinical investigations are crucial to achieve this issue. Distinctive in vitro investigations assessed the biomechanical conduct of zirconia inserts with prosthetic recreations. The crack quality of zirconia crowns on zirconia inserts was contrasted with that of metal-fired crowns on titanium inserts, in an upper focal incisor model. No distinction was found between inserts, with and without cyclic stacking before crack test. Similar creators additionally indicated that readiness of zirconia inserts to get prosthetic crown may contrarily influence the break quality, regardless of whether it was still in a worthy clinical range. Another in vitro investigation assessed the break quality of zirconia embeds in examination with that of titanium embeds under a 130° calculated burden, mimicking that of an upper focal incisor. Regardless of the high scattering of break loads (ordinary of earthenware materials), the mean crack quality extended inside the constraints of clinical acknowledgment.

With alert, it is conceivable to insist that from trial preclinical investigations, the biomechanical conduct of zirconia inserts doesn't contrast from that of titanium inserts. In this way, no biomechanical contraindications are available for clinical utilization of zirconia inserts.

La mayoría de los estudios clínicos se han centrado en conseguir y mantener la osteointegración a lo largo del tiempo. En estos estudios, la principal causa de fracaso se atribuye a la pérdida ósea periférica o, posiblemente, a la pérdida de osteointegración (véase más adelante). Sin embargo, un estudio clínico consideró únicamente la fractura de la incrustación como causa de fracaso: la tasa de supervivencia fue del 92,5 % después de unos 5 años, no se ha tenido en cuenta la pérdida de osteointegración.