title: Influence of photo-activation source on enamel demineralization around restorative materials.
abstract: This study evaluated the effects of the photoactivation source and restorative material on the development of caries-like lesions on human enamel after an in vitro pH challenge. Enamel cavities were prepared in 36 blocks, which were assigned to two groups according to the restorative material: resin-modified glass ionomer (RMGI) and composite resin (CR). Samples were exposed to quartz-tungsten-halogen lamp, argon-ion laser, or light-emitting diode (n = 6). The Knoop microhardness (KHN) values of the top surface of all materials were evaluated. Restored enamel blocks were thermocycled and subjected to 10 demineralization-remineralization cycles at 37°C. KHN analysis of the superficial enamel was performed by four indentations located 100 μm from the restoration margin. The material KHN was not affected by the photoactivation source. No significant difference in KHN was noted between CR and RMGI. The enamel surface around RMGI exhibited a higher KHN (272.8 KHN) than the enamel around CR (93.3 KHN), regardless of the photoactivation source. Enamel demineralization around the dental restoration was not influenced by the photoactivation source. Less enamel demineralization was observed around the RMGI than around the CR restoration.
authors: Department of Restorative Dentistry, Graduate Division, Univ Guarulhos, Guarulhos, SP, Brazil.
authors: Juliana de Oliveira
authors: Jde O
authors: Ferla
authors: José Augusto
authors: JA
authors: Rodrigues
authors: César Augusto Galvão
authors: CA
authors: Arrais
authors: Ana Cecília Correa
authors: AC
authors: Aranha
authors: Alessandra
authors: A
authors: Cassoni
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D055117:Curing Lights, Dental; D003743:Dental Enamel / Q000528:radiation effects*; D003793:Dental Restoration, Permanent; D005899:Glass Ionomer Cements / Q000737:chemistry / Q000528:radiation effects*; D006245:Hardness Tests; D006801:Humans; D008422:Materials Testing; D055668:Photochemical Processes; D013499:Surface Properties / Q000528:radiation effects; D013997:Time Factors; D017001:Tooth Demineralization / Q000209:etiology*
chemical_list: D003188:Composite Resins; D005899:Glass Ionomer Cements