RESUMO
This study investigated the use of injectable poly(propylene fumarate) (PPF) formulations for mandibular fracture stabilization applications. A full factorial design with main effects analysis was employed to evaluate the effects of the PPF:N-vinyl pyrrolidone (NVP, crosslinking agent) ratio and dimethyl toluidine (DMT, accelerator) concentration on key physicochemical properties including setting time, maximum temperature, mechanical properties, sol fraction, and swelling ratio. Additionally, the effects of formulation crosslinking time on the mechanical and swelling properties were investigated. The results showed that increasing the PPF:NVP ratio from 3:1 to 4:1 or decreasing the DMT concentration from 0.05 to 0.01 v/w % significantly decreased all mechanical properties as well as significantly increased the sol fraction and swelling ratio. Also, increasing the crosslinking time at 37°C from 1 to 7 days significantly increased all mechanical properties and decreased both the sol fraction and swelling ratio. This study further showed that the flexural stiffness of ex vivo stabilized rabbit mandibles increased from 1.7 ± 0.3 N/mm with a traditional mini-plate fixator to 14.5 ± 4.1 N/mm for the 4:1 (0.05 v/w % DMT) PPF formulation at day 1. Overall, the formulations tested in this study were found to have properties suitable for potential further consideration in mandibular fracture fixation applications.
Assuntos
Implantes Absorvíveis , Materiais Biocompatíveis/uso terapêutico , Cimentos Ósseos/uso terapêutico , Cementoplastia , Fumaratos/uso terapêutico , Fraturas Mandibulares/terapia , Polipropilenos/uso terapêutico , Animais , Materiais Biocompatíveis/administração & dosagem , Placas Ósseas , Parafusos Ósseos , Força Compressiva , Reagentes de Ligações Cruzadas/farmacologia , Fixação Interna de Fraturas , Fumaratos/administração & dosagem , Técnicas In Vitro , Injeções Intralesionais , Fraturas Mandibulares/cirurgia , Teste de Materiais , Modelos Anatômicos , Maleabilidade , Polimerização , Polipropilenos/administração & dosagem , Pirrolidinonas/farmacologia , Coelhos , Estresse Mecânico , Temperatura , Fatores de Tempo , Toluidinas/farmacologia , Toluidinas/uso terapêutico , Torção MecânicaRESUMO
Abnormalities of tooth shape and size generally coexist, as both are determined during the morphodifferentiation stage of odontogenesis. This report describes a case of lobodontia exhibiting multiple dental anomalies of which, "fang like" cuspids, multituberculism of molars, hypodontia along with severe generalized microdontia are distinctive. Radiographic features, diagnostic convolutions, differential diagnosis and clinical significance have also been highlighted.
Assuntos
Anormalidades Dentárias/diagnóstico por imagem , Adulto , Humanos , Hipercementose/diagnóstico por imagem , Masculino , Radiografia , Coroa do Dente/anormalidadesRESUMO
Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper.