Effect of shade and thickness on the microhardness of resin-based composite specimens at different points considering curing light beam’s inhomogeneity

Autor: Lan Wang, Hyemin Ku, Dohyun Kim, Sung-Ho Park
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: BMC Oral Health, Vol 24, Iss 1, Pp 1-8 (2024)
Druh dokumentu: article
ISSN: 1472-6831
73558524
DOI: 10.1186/s12903-024-04647-2
Popis: Abstract Background Recent studies have reported the inhomogeneity in the light emitted by dental light-curing units (LCUs). It is essential to understand how this uneven light distribution affects the physical properties of resin-based composites (RBCs) at various points across their surfaces. This study aimed to evaluate the effect of LCU beam’s inhomogeneity on the microhardness of RBCs with different shades and thicknesses. Methods Four body (A1B, A2B, A3B, and A4B), one dentin (A3D), and one enamel shade (A3E) of RBC (Filtek Z350 XT) were examined. The specimens were fabricated in four thicknesses (1, 2, 3, and 4 mm) and subjected to a 40-second light-curing. Vickers microhardness testing was performed at the center point, and 3 mm left and right from the center at the bottom surface of each sample. The LCU beam profile was characterized using a beam profiler, while irradiance after specimen passage was measured using a spectrometer. One-way analysis of variance (ANOVA) and Tukey’s post-hoc tests were used to analyze the effects of shades and thicknesses on irradiance and microhardness, respectively. One-way repeated-measures ANOVA was used to compare the microhardness across different points. Pearson’s correlation analysis examined the relationship between irradiance and microhardness. Results The beam profile of LCU revealed inhomogeneous light distribution. Light irradiance was decreased with both the increase in thickness and darker shade of the specimens (p
Databáze: Directory of Open Access Journals
Externí odkaz: