Sharafeddin Farahnaz, Alavi Ali Asghar, Siabani Saba, Safari Mina
Dept. of Operative Dentistry, Biomaterials Research Center, School of Dentistry, Shiraz University of Medial Sciences, Shiraz, Iran.
Postgraduate Student, Dept. of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
J Dent (Shiraz). 2020 Jun;21(2):132-140. doi: 10.30476/DENTJODS.2019.77762.0.
The clinical success of glass ionomer cement (GIC) restorations depends on the strength of its bonding to dentin, yet the bond strength of nanohydroxyapatite (nHAp) added GIC to dentin needs to be investigated.
This study aimed to assess if the type of GIC containing nHAp and dentin depth could affect the shear bond strength (SBS).
In this experimental study, 60 freshly extracted intact third molars were randomly divided into two main groups of flat occlusal dentin with different cuts as superficial (S); just below the dentinoenamel junction (DEJ) and deep (D); 2mm below DEJ. After conditioning with 20% polyacrylic acid, each group were randomly assigned to the tested GIC (n=10) subgroups as (1) Fuji IX Extra+nHAp, (2) Fuji II LC+nHAp and (3) Zirconomer+nHAp. Plastic tubes were placed on the pre-treated surfaces and filled with one of the GIC, then stored in an incubator at 37 oC and 100% humidity for 24hr. The specimens were thermocycled at5/55 oC for 500 cycles and subjected to SBS test using a universal testing machine (1 mm/min). The data analyzed by Mann-Whitney and Kruskal-Wallis test (< 0.05).
The means of SBS of Fuji II LC+nHAp was significantly higher than Fuji IX+nHAp and Zirconomer+nHAp both in superficial and deep dentin (< 0.05). The means of SBS of Fuji IX Extra+nHAp and Zirconomer+nHAp subgroups in superficial dentin were higher than deep dentin, this differences was statistically significant (= 0.0001 and = 0.009, respectively).
It can conclude that SBS was influenced by type of GIC and depth of dentin.
玻璃离子水门汀（GIC）修复体的临床成功取决于其与牙本质的粘结强度，然而，添加纳米羟基磷灰石（nHAp）的GIC与牙本质的粘结强度仍需研究。
本研究旨在评估含nHAp的GIC类型和牙本质深度是否会影响剪切粘结强度（SBS）。
在本实验研究中，60颗新鲜拔除的完整第三磨牙被随机分为两组，即具有不同切割方式的平坦咬合面牙本质，浅部（S）：刚好在牙本质釉质交界处（DEJ）下方；深部（D）：在DEJ下方2mm。用20%聚丙烯酸处理后，每组随机分为测试的GIC（n = 10）亚组，分别为（1）Fuji IX Extra + nHAp、（2）Fuji II LC + nHAp和（3）Zirconomer + nHAp。将塑料管放置在预处理过的表面上，并用其中一种GIC填充，然后在37℃、湿度100%的培养箱中储存24小时。将标本在5/55℃下进行500次热循环，并使用万能试验机（1mm/分钟）进行SBS测试。数据采用Mann-Whitney和Kruskal-Wallis检验进行分析（<0.05）。
Fuji II LC + nHAp在浅部和深部牙本质中的SBS均值均显著高于Fuji IX + nHAp和Zirconomer + nHAp（<0.05）。Fuji IX Extra + nHAp和Zirconomer + nHAp亚组在浅部牙本质中的SBS均值高于深部牙本质，这种差异具有统计学意义（分别为=0.0001和=0.009）。
可以得出结论，SBS受GIC类型和牙本质深度的影响。
