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, Chengdu 610041, China.
Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
J Dent. 2019 Oct;89:103193. doi: 10.1016/j.jdent.2019.103193. Epub 2019 Aug 30.
The remineralization of dentin at a bonded interface would help to strengthen the bonded interface and inhibit secondary caries, and would prolong the longevity of restoration. The aim of this study was to investigate the remineralization of demineralized human dentin in a dental biofilm environment via an adhesive containing nanoparticles of amorphous calcium phosphate (NACP).
Dentin demineralization was promoted by subjecting samples to a Streptococcus mutans acidic biofilm for 24 h. Samples were divided into a control group, a commercial fluoride-releasing adhesive group, and an NACP adhesive group. All samples were subjected to a remineralization protocol consisting of 4-h exposure per 24-h period in brain heart infusion broth plus 1% sucrose (BHIS) followed by immersion in artificial saliva for the remaining period. The pH of BHIS after 4-h immersion was measured every other day. After 10 days, the biofilm was assessed for colony-forming unit (CFU) count, lactic acid production, live/dead staining, and calcium and phosphate content. The mineral changes in the demineralized dentin samples were analyzed by transverse microradiography, hardness measurement, X-ray diffraction characterization, and scanning electron microscopy.
The NACP adhesive achieved acid neutralization, decreased biofilm CFU count, decreased biofilm lactic acid production, and increased biofilm calcium and phosphate content (P < 0.05). The NACP adhesive group had higher remineralization value than the commercial fluoride-releasing adhesive group (P < 0.05).
The NACP adhesive was effective in remineralizing dentin lesions in a biofilm model. Its ability to protect bond interface, inhibit secondary caries, and prolong the longevity of restoration is promising.
Using NACP-containing adhesives could be recommended because of the protective ability of its hybrid layer even under a biofilm-challenged environment.
在粘结界面进行牙本质再矿化有助于增强粘结界面，抑制继发龋，延长修复体的寿命。本研究旨在通过含有无定形磷酸钙（NACP）纳米颗粒的粘结剂来研究牙本质在牙菌斑环境中的脱矿再矿化。
通过使样本暴露于变形链球菌酸性生物膜中 24 小时来促进牙本质脱矿。将样本分为对照组、商用含氟释放粘结剂组和 NACP 粘结剂组。所有样本均接受再矿化方案，即每 24 小时暴露 4 小时，在脑心浸液肉汤加 1%蔗糖（BHIS）中进行，其余时间浸泡在人工唾液中。每隔一天测量 BHIS 在 4 小时浸泡后的 pH 值。10 天后，评估生物膜的菌落形成单位（CFU）计数、乳酸生成、死活染色以及钙和磷含量。通过横向显微射线照相术、硬度测量、X 射线衍射特征和扫描电子显微镜分析脱矿牙本质样本的矿物质变化。
NACP 粘结剂实现了酸中和，降低了生物膜 CFU 计数，减少了生物膜乳酸生成，增加了生物膜钙和磷含量（P<0.05）。NACP 粘结剂组的再矿化值高于商用含氟释放粘结剂组（P<0.05）。
NACP 粘结剂在生物膜模型中有效地再矿化牙本质病变。其保护粘结界面、抑制继发龋和延长修复体寿命的能力具有广阔的前景。
由于其混合层的保护能力，即使在生物膜挑战的环境下，使用含 NACP 的粘结剂也可能被推荐。
