Hafny Waleed M, Ibrahim Imam M, El-Demellawy Mohamed, Abdel Sadek Hoda M
Department of Fixed Prosthodontics - Faculty of Dentistry, Ain Shams University, Organization of African Unity, St, El-Qobba Bridge, El Weili, Cairo Governorate, Egypt.
BMC Oral Health. 2025 Jan 8;25(1):41. doi: 10.1186/s12903-024-05336-w.
Home bleaching is a promising option for addressing discolored teeth conservatively. However, its impact on the physical and mechanical properties of indirect restorations remains unknown. This study provides comparative insights into the material responses to aesthetic treatments by assessing the effects of home bleaching agents on two hybrid ceramics: VITA ENAMIC and Grandio Blocs. The focus is on evaluating color stability and biaxial flexural strength.
60 discs (12 × 1 mm) were prepared from hybrid ceramics. Specimens were divided into two groups according to type of hybrid ceramic (30 specimens in each group); group A: VITA ENAMIC, group B: Grandio Blocs. Each group was further subdivided into 3 subgroups according to the concentration of home bleaching agents used (10 specimens in each subgroup); subgroup C: unbleached control group, subgroup C10%: carbamide peroxide 10% bleaching agent, and subgroup C35%: carbamide peroxide 35% bleaching agent. Samples of subgroup C10% were bleached with Home Bleaching Opalescence PF (10%) for 8 h per day for 14 days, as directed by the manufacturer. Samples of subgroup C35% were bleached using WHITEsmile Carbamide Peroxide (35%), following the manufacturer's directions for 30 min every day for 14 days. Color change (ΔE) was assessed using of the CIE Lab* system. Then, the biaxial flexural strength test was done. The data were analyzed using two-way ANOVA tests and Weibull analysis.
VITA ENAMIC samples exhibited significantly higher color change than Grandio Blocs (p < 0.001), while Grandio Blocs showed significantly higher biaxial flexural strength (p < 0.001). The concentration of the bleaching agent had no significant effect on color change (p = 0.086). However, regardless of its concentration, bleaching significantly reduced biaxial flexural strength in both materials (p < 0.001). Weibull analysis showed that Grandio Blocs had higher characteristic strength, while VITA ENAMIC demonstrated more reliable failure behavior.
Compared to Grandio Blocs, VITA ENAMIC exhibited a greater color change with both 10% and 35% carbamide peroxide home bleaching agents. Additionally, both concentrations of carbamide peroxide reduced the biaxial flexural strength of hybrid ceramics. These findings can guide clinicians in selecting hybrid ceramics based on clinical demands for aesthetics and durability. VITA ENAMIC offers greater structural reliability and predictability for aesthetic restorations, while Grandio Blocs provide superior durability and stress resistance for high-stress clinical applications.
家庭漂白是一种保守治疗牙齿变色的有前景的方法。然而，其对间接修复体物理和机械性能的影响尚不清楚。本研究通过评估家庭漂白剂对两种混合陶瓷（维他灵瓷（VITA ENAMIC）和格兰迪欧嵌体（Grandio Blocs））的影响，对美学治疗的材料反应提供了比较性见解。重点是评估颜色稳定性和双轴弯曲强度。
从混合陶瓷制备60个圆盘（12×1毫米）。根据混合陶瓷类型将标本分为两组（每组30个标本）；A组：维他灵瓷，B组：格兰迪欧嵌体。每组再根据所用家庭漂白剂的浓度进一步细分为3个亚组（每个亚组10个标本）；C亚组：未漂白对照组，C10%亚组：10%过氧化脲漂白剂，C35%亚组：35%过氧化脲漂白剂。按照制造商的指示，C10%亚组的样本每天用家庭美白奥普泰斯PF（10%）漂白8小时，持续14天。C35%亚组的样本使用美白微笑过氧化脲（35%），按照制造商的指示每天漂白30分钟，持续14天。使用CIE Lab*系统评估颜色变化（ΔE）。然后，进行双轴弯曲强度测试。使用双向方差分析和威布尔分析对数据进行分析。
维他灵瓷样本的颜色变化显著高于格兰迪欧嵌体（p<0.001），而格兰迪欧嵌体的双轴弯曲强度显著更高（p<0.001）。漂白剂浓度对颜色变化没有显著影响（p = 0.086）。然而，无论浓度如何，漂白均显著降低了两种材料的双轴弯曲强度（p<0.001）。威布尔分析表明，格兰迪欧嵌体具有更高的特征强度，而维他灵瓷表现出更可靠的失效行为。
与格兰迪欧嵌体相比，维他灵瓷在使用10%和35%过氧化脲家庭漂白剂时颜色变化更大。此外，两种浓度的过氧化脲均降低了混合陶瓷的双轴弯曲强度。这些发现可以指导临床医生根据美学和耐用性的临床需求选择混合陶瓷。维他灵瓷为美学修复提供了更高的结构可靠性和可预测性，而格兰迪欧嵌体为高应力临床应用提供了卓越的耐用性和抗应力性。
