State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No. 14, 3rd section, Renmin Road South, Chengdu, 610041, Sichuan, China.
Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, 21201, USA.
Clin Oral Investig. 2021 Sep;25(9):5375-5390. doi: 10.1007/s00784-021-03846-3. Epub 2021 Apr 23.
Dental caries is closely associated with acid-producing bacteria, and Streptococcus mutans is one of the primary etiological agents. Bacterial accumulation and dental demineralization lead to destruction of bonding interface, thus limiting the longevity of composite. The present study investigated remineralization effectiveness of adhesive containing nanoparticles of amorphous calcium phosphate (NACP) in a stimulated oral biofilm environment.
The enamel blocks were immersed in demineralization solution for 72 h to imitate artificial initial carious lesion and then subjected to a Streptococcus mutans biofilm for 24 h. All the samples then underwent 4-h demineralization in brain heart infusion broth with sucrose (BHIS) and 20-h remineralization in artificial saliva (AS) for 7 days. The daily pH of BHIS after 4-h incubation, lactic acid production, colony-forming unit (CFU) count, and content of calcium (Ca) and phosphate (P) in biofilm were evaluated. Meanwhile, the remineralization effectiveness of enamel was analyzed by X-ray diffraction (XRD), surface microhardness testing, transverse microradiography (TMR) and scanning electron microscopy (SEM).
The NACP adhesive released abundant Ca and P, achieved acid neutralization, reduced lactic acid production, and lowered CFU count (P < 0.05). Enamel treated with NACP adhesive demonstrated the best remineralization effectiveness with remineralization value of 52.29 ± 4.79% according to TMR. Better microhardness recovery of cross sections and ample mineral deposits were also observed in NACP group.
The NACP adhesive exhibited good performance in remineralizing initial enamel lesion with cariogenic biofilm.
The NACP adhesive is promising to be applied for the protection of bonding interface, prevention of secondary caries, and longevity prolonging of the restoration.
龋齿与产酸菌密切相关，其中变形链球菌是主要的病因之一。细菌的积聚和牙齿脱矿导致结合界面的破坏，从而限制了复合树脂的使用寿命。本研究旨在研究含有纳米无定形磷酸钙（NACP）的胶粘剂在模拟口腔生物膜环境中的再矿化效果。
将釉质块浸入脱矿溶液中 72 小时，以模拟人工初始龋损，然后接种变形链球菌生物膜 24 小时。所有样本随后在含蔗糖的脑心浸液肉汤（BHIS）中进行 4 小时脱矿化，在人工唾液（AS）中进行 20 小时再矿化，共 7 天。每天测定 BHIS 孵育 4 小时后的 pH 值、乳酸生成量、菌落形成单位（CFU）计数以及生物膜中钙（Ca）和磷（P）的含量。同时，通过 X 射线衍射（XRD）、表面显微硬度测试、横向显微放射摄影术（TMR）和扫描电子显微镜（SEM）分析釉质的再矿化效果。
NACP 胶粘剂释放出丰富的 Ca 和 P，实现了酸中和，减少了乳酸的生成，并降低了 CFU 计数（P<0.05）。用 NACP 胶粘剂处理的釉质根据 TMR 显示出最佳的再矿化效果，再矿化值为 52.29±4.79%。在 NACP 组中还观察到横截面的显微硬度恢复更好，并有大量的矿物质沉积。
NACP 胶粘剂在再矿化致龋生物膜中的初始釉质病变方面表现出良好的性能。
NACP 胶粘剂有望应用于保护粘结界面、预防继发龋和延长修复体的使用寿命。
