Beverage-Induced Surface Changes in Biomimetic Dental Resin Composite: AFM and Bacterial Analysis.

Abstract

Objective:  Continuous advancements in composite resin materials have revolutionized and expanded its clinical use, improving its physical and mechanical properties. Attaining and retaining surface texture and gloss are crucial for the long-term durability of the composite resin material. This study investigated the supra-nanospherical filler composite material compared with different composite resin materials immersed in different beverages. The study evaluated their surface roughness and subsequent adhesion of bacteria.

Materials and methods:  A total of 144 specimens were made, using Teflon mold from different composite materials. Eighty-four specimens were used for surface roughness testing, using four different resin composite materials, Tetric N-Ceram (Ivoclar Vivadent, Schaan, Liechtenstein), Multichrome (Harvard Dental, Germany), Filtek Z350 XT (3M ESPE, Minnesota, United States), and Palfique LX5 (Tokuyama Dental Corporation, Taitō-Ku, Tokyo, Japan; n = 21). They were further subdivided into three subgroups according to the immersion solution (n = 7) for Monster, Gatorade, and deionized water, which served as the control group. Surface roughness values were tested via atomic force microscopy (AFM). Then, for biofilm testing the bacterial count was performed on the remaining 60 composite specimens from the four tested composite materials (n = 15), that were subdivided randomly based on the immersion solutions into three subgroups (n = 5).

Statistical analysis:  Data were collected and statistically analyzed using the Kruskal-Wallis test followed by Dunn's post hoc test with Bonferroni's correction (p ≤ 0.05). The intergroup comparison showed a significant difference among different composite materials (p < 0.05), with the Multichrome showing the highest roughness values. Also, there was a significant difference between all composite materials with different beverages, with Palfique LX5 showing the lowest average roughness (Ra) values. All studied materials' average surface roughness, however, remained below the crucial Ra value of 0.2 μm. For the bacterial count, there was a significant difference between different materials in different beverages (p < 0.05), with Z350 XT and Palfique LX5 showing the lowest bacterial count.

Conclusion:  Supra-nanospherical composite (Palfique LX5) exhibited better resistance to different beverage challenges regarding surface roughness, while nanohybrid composite (Z350) showed the least bacterial adherence.