ABSTRACT
The present meta-analysis initially evaluates the reliability of dental maturation in the identification of the circumpubertal growth phases, essentially for determining treatment timing in orthodontics. A literature survey was performed using the Medline, LILACS and SciELO databases, and the Cochrane Library (2000 to 2011). Studies of the correlation between dental and cervical vertebral maturation methods were considered. The mandibular canine, the first and second premolars, and the second molar were investigated. After the selection, six articles qualified for the final analysis. The overall correlation coefficients were all significant, ranging from 0.57 to 0.73. Five of these studies suggested the use of dental maturation as an indicator of the growth phase. However, the diagnostic performance analysis uncovered limited reliability only for the identification of the pre-pubertal growth phase. The determination of dental maturity for the assessment of treatment timing in orthodontics is not recommended.
Subject(s)
Age Determination by Teeth/methods , Growth/physiology , Puberty/physiology , Age Determination by Skeleton/statistics & numerical data , Bicuspid/growth & development , Cervical Vertebrae/growth & development , Cuspid/growth & development , Humans , Molar/growth & developmentABSTRACT
The aim of this study was to assess the cytotoxicity of orthodontic materials (brackets, wires, resin, elastomers and silver solder) using Saccharomyces cerevisiae as a model organism. The induction of cytotoxicity was assessed by two different tests using the wild-type S. cerevisiae strain FF18733: (1) direct exposure to orthodontic materials in YPD broth, and (2) exposure to artificial commercial saliva pre-treated with orthodontic materials. Only the silver solder was tested in mutant S. cerevisiae strains to investigate the origin of the observed cytotoxicity. Colony forming units per mL counts were carried out in all experiments and compared to controls to detect significant survival differences. The results showed that only the silver solder induced significant cytotoxicity, which might have occurred via oxidative stress, although this mechanism is not completely understood. Moreover, S. cerevisiae proved to be a reliable and useful model microorganism for evaluating the cytotoxicity of clinical materials.
Subject(s)
Dental Materials/toxicity , Orthodontics , Saccharomyces cerevisiae/drug effects , Colony Count, Microbial , Composite Resins/toxicity , Culture Media , DNA Repair Enzymes/genetics , Dental Alloys/toxicity , Dental Soldering , Dose-Response Relationship, Drug , Elastomers/toxicity , Endodeoxyribonucleases/genetics , Free Radical Scavengers/metabolism , Humans , Materials Testing , Microbial Viability/drug effects , Mutation/genetics , Orthodontic Brackets , Orthodontic Wires , Oxidative Stress/drug effects , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/genetics , Saliva, Artificial/chemistry , Silver/toxicity , Stainless Steel/toxicity , Superoxide Dismutase/genetics , Superoxide Dismutase-1 , Time FactorsABSTRACT
Algunos años atrás, los dientes tratados endodonticamente eran considerados frágiles y se creía que con la utilización de retenedores intra-radiculares se reforzaría la estructura dentaria. Actualmente la función de un poste esta más relacionada a la retención del material restaurador, sin ninguna pretensión de reforzar la estructura radicular remanente. Existe una gran variedad de postes disponibles en el mercado, desde los metálicos fundidos hasta los pre-fabricados. Lospostes pre-fabricados pueden ser metálicos, cerámicos o reforzados con fibras, ya sea de carbono o de vidrio. Los postes de fibra de vidrio están siendo actualmente indicados en lapráctica odontológica, debido a su excelente estética, asociada a su fácil manipulación, adecuada resistencia mecánica y buena relación costo/beneficio. El presente trabajo pretende mostrar a través de una revisión de literatura, las principales características clínicas, propiedades físicas - mecánicas, ventajas y limitaciones de los postes pre-fabricados, con la finalidad de facilitar suindicación en la odontología clínica.
Many years ago the endodontically treated teeth were considered weak and traditional belief was that the dental structure would be strengthened by using posts into root canal. Nowadays the function of a post is more related to retain a core, than replaced the lost tooth structure to strength it. Many varieties of posts are available on the market, from metal cast to prefabricatedposts. The prefabricated posts may be metallic, ceramic, carbon fiber-reinforced or quartz fiberreinforced.At the moment quartz fiber-reinforced posts are indicated in dental practice, due to their excellent aesthetic, associated to their easy manipulation, an appropriate mechanical resistance and good relation cost/benefits. The aim of the present literature review is to reveal the main clinical characteristics, physical-mechanical properties, advantages and limitations ofprefabricated posts, to give its use in clinical practice.
