RESUMO
Infraocclusion occurs at an early age and becomes worse with age, causing increased damage in young children. Extraction of affected teeth is the preferred treatment modality for prevention of possible complications. It is rare for a primary molar to temporarily exhibit secondary failure of eruption, followed by regeneration of full eruptive capacity. This report was written to describe two patients who experienced spontaneous eruption of an infraoccluded primary molar at approximately 7 years of age. While watchful waiting is not always a suitable treatment option, we propose that extraction be deferred until the first permanent molar erupts, unless significant problems occur.
Assuntos
Dente Molar , Dente Decíduo , Criança , Pré-Escolar , Arco Dental , Humanos , Erupção DentáriaRESUMO
Treatment of mononuclear nonheme iron(II) complexes bearing two cis-labile sites with perbenzoic acids results in the self-hydroxylation of the aromatic ring to form the corresponding iron(III)-salicylate complexes through an intramolecular oxo-transfer process.
Assuntos
Benzoatos/química , Ferro/química , Heme/química , Hidroxilação , Modelos Moleculares , Estrutura Molecular , OxirreduçãoAssuntos
Álcoois/química , Heme/química , Ferro/química , Oxigênio/química , Cinética , Ligantes , Estrutura Molecular , Oxirredução , Análise EspectralRESUMO
Nonheme oxoiron(IV) complexes of two pentadentate ligands, N4Py (N,N-bis(2-pyridylmethyl)-bis(2-pyridyl)methylamine) and Bn-tpen (N-benzyl-N,N',N'-tris(2-pyridylmethyl)-1,2-diaminoethane), have been generated and found to have spectroscopic properties similar to the closely related tetradentate TPA (tris(2-pyridylmethyl)amine) complex reported earlier. However, unlike the TPA complex, the pentadentate complexes have a considerable lifetime at room temperature. This greater thermal stability has allowed the hydroxylation of alkanes with C-H bonds as strong as 99.3 kcal/mol to be observed at room temperature. Furthermore, a large deuterium KIE value is found in the oxidation of ethylbenzene. These observations lend strong credence to postulated mechanisms of mononuclear nonheme iron enzymes that invoke the intermediacy of oxoiron(IV) species.