Jauregui-Ulloa Jaccare T, Luke Brooklyn N, Kunapareddy Aditya, Griggs Jason A, Price Richard B, Salazar Marocho Susana M
Department of Biomedical Materials Science, School of Dentistry, University of Mississippi Medical Center, Jackson, USA.
Department of Dental Clinical Sciences, Dalhousie University, Halifax, Canada.
J Dent. 2025 Sep;160:105870. doi: 10.1016/j.jdent.2025.105870. Epub 2025 Jun 1.
This study evaluated the effect of the light curing unit (LCU), light curing technique (LCT), and insertion technique (CIT) of resin-based composite (RBC) on the microhardness at various depths of RBC specimens.
A mesio-occlusal-distal (MOD) mold was used to make samples of conventional RBC (n = 3/group) using either an incremental (I) or a bulk-fill (BF) technique. The RBC was photocured using one of three different LCUs (Bluephase Style 20i for 15 s (I) and 10 s (BF), Monet laser for 1 s (I) and 3 s (BF), and Pinkwave for 10 s (I) and 20 s (BF). The LCUs were positioned either only over the center of the mold, or at three sites (side-center-side). The Vickers microhardness was measured at different distances from the top of the sample. Four-way ANOVA and Pareto chart analysis were performed (α=0.05).
All the experimental factors were significant (p ≤ 0.05). The Pinkwave produced the highest microhardness, followed by the Bluephase and Monet. Light exposure from the three sites produced higher microhardness than light exposure only at the center of the mold. The incremental technique resulted in higher microhardness than the bulk-fill technique. The depth of the RBC negatively affected the microhardness.
RBC microhardness varied depending on the type of LCU used. The Pinkwave delivered the most energy and produced the highest microhardness values.
To ensure uniform microhardness of the RBC, the tip of the LCU should cover all aspects of the restoration (occlusal, mesial, and distal surfaces).
本研究评估了树脂基复合材料（RBC）的光固化单元（LCU）、光固化技术（LCT）和充填技术（CIT）对RBC标本不同深度处显微硬度的影响。
使用近中-咬合-远中（MOD）模具，采用分层充填（I）或一次性充填（BF）技术制作传统RBC样本（n = 3/组）。使用三种不同的LCU之一对RBC进行光固化（Bluephase Style 20i，I技术照射15秒、BF技术照射10秒；Monet激光，I技术照射1秒、BF技术照射3秒；Pinkwave，I技术照射10秒、BF技术照射20秒）。LCU要么仅放置在模具中心上方，要么放置在三个位置（边缘-中心-边缘）。在距样本顶部不同距离处测量维氏显微硬度。进行四因素方差分析和帕累托图分析（α = 0.05）。
所有实验因素均具有显著性（p≤0.05）。Pinkwave产生的显微硬度最高，其次是Bluephase和Monet。从三个位置照射光产生的显微硬度高于仅在模具中心照射光。分层充填技术产生的显微硬度高于一次性充填技术。RBC的深度对显微硬度有负面影响。
RBC的显微硬度因所使用的LCU类型而异。Pinkwave传递的能量最多，产生的显微硬度值最高。
为确保RBC的显微硬度均匀，LCU的尖端应覆盖修复体的所有面（咬合面、近中面和远中面）。
