Dental Biomaterials Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Pediatric Dentistry and Orthodontics Department, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
Int J Nanomedicine. 2024 Oct 12;19:10307-10317. doi: 10.2147/IJN.S478930. eCollection 2024.
There is a critical need to address concerns surrounding the potential impact of bleaching gels specifically on the tooth substrate. Therefore, this laboratory investigation aimed to assess the impact of a hydrogen peroxide (HP)-free bleaching (HiSmile) in comparison to an HP-based bleaching (Opalescence Regular) on the surface and mechanical characteristics of tooth substrate.
Sixty sound human premolar teeth were sectioned to produce dentin fragments and divided into two primary groups based on the bleaching agent used. Each group was subdivided into three subgroups (n = 10) per distinct bleaching regimens: (T) fragments underwent a 7-day immersion in distilled water at 37°C without any bleaching treatment, (T) fragments underwent a 7-day immersion in distilled water at 37°C, with the application of bleaching gel occurring on the seventh day for 10 minutes, and (T) fragments underwent a bleaching regimen for seven consecutive days, each session lasting for 10 minutes. The initial and final evaluations of surface roughness, nano-hardness, and elastic modulus were performed. Following the bleaching regimens of T, a composite stub was fabricated on the dentin fragments for the shear bond strength (SBS) test. Statistical testing was accomplished using the analysis of variance (P < 0.05).
HP-based bleaching gel showed significant differences between measurement intervals in surface roughness, elastic modulus, and SBS parameters (P < 0.05). In contrast, HP-free bleaching gel showed insignificant differences within the group (P > 0.05). The SBS between dentin-composite was significantly affected with the use of HP-based bleaching gel, while HP-free bleaching gel showed insignificant difference between measurement intervals. The qualitative validation of the treatment's impact was further demonstrated using the scanning electron microscopy.
The findings suggest that the bonding stability of composite restorations to dentin may be compromised after bleaching with an HP-based gel, whereas immediate bonding procedures can be safely conducted following the application of an HP-free bleaching gel.
有必要解决人们对漂白凝胶潜在影响的担忧，特别是对牙本质的潜在影响。因此，本实验室研究旨在评估一种不含过氧化氢（HP）的漂白剂（HiSmile）与基于 HP 的漂白剂（Opalescence Regular）对牙本质基质表面和机械特性的影响。
将 60 颗健康的人上前磨牙切成牙本质碎片，并根据使用的漂白剂分为两个主要组。每个组根据不同的漂白方案进一步分为三个亚组（n = 10）：（T）碎片在 37°C 的蒸馏水中浸泡 7 天，不进行任何漂白处理；（T）碎片在 37°C 的蒸馏水中浸泡 7 天，第 7 天应用漂白凝胶 10 分钟；（T）碎片进行连续 7 天的漂白处理，每次持续 10 分钟。在初始和最终阶段评估表面粗糙度、纳米硬度和弹性模量。在 T 处理完成后，在牙本质碎片上制作复合嵌体进行剪切结合强度（SBS）测试。使用方差分析（P < 0.05）进行统计测试。
基于 HP 的漂白凝胶在表面粗糙度、弹性模量和 SBS 参数的测量间隔之间显示出显著差异（P < 0.05）。相比之下，无 HP 的漂白凝胶在组内显示出无显著差异（P > 0.05）。基于 HP 的漂白凝胶的使用显著影响牙本质-复合材料之间的 SBS，而无 HP 的漂白凝胶在测量间隔之间没有显著差异。扫描电子显微镜进一步验证了治疗效果的定性影响。
研究结果表明，使用基于 HP 的凝胶进行漂白后，复合修复体与牙本质的粘结稳定性可能会受到影响，而在应用无 HP 的漂白凝胶后，可以安全地进行即刻粘结程序。
