Quteifani Morgana, Madarati Ahmad A, Layous Kinda, Tayyan Mouhammad Al
Department of Endodontic and Operative Dentistry, College of Dentistry, Damascus University, Syria.
Department of Retorative Dental Sciences, College of Dentistry, Taibah University, Saudi Arabia; Department of Endodontic and Operative Dentistry, College of Dentistry, Aleppo University, Syria.
Eur Endod J. 2019 Dec 3;4(3):127-132. doi: 10.14744/eej.2019.49369. eCollection 2019.
To compare the effects of different irrigation protocols, with/without laser activation, on the radicular dentine's micro-hardness.
Eighty-two human extracted premolars were decoronated and divided into 7 groups. Roots were longitudinally split into two halves. The micro-hardness was measured for one half before and after irrigation protocols. The groups were; G1: MTAD without laser-activation, G2: MTAD with laser-activation, G3: sodium-hypochlorite (SH) with laser-activation, G4: SH then EDTA with laser-activation, G5: SH then MTAD with laser-activation, G6: SH without laser-activation. G7: distilled water (control). In the two-irrigants groups G4 and G5), samples were irrigated first with SH then with MTAD or EDTA irrigants, which were activated by the laser. The difference between the before- and after-irrigation micro-hardness was calculated to obtain the micro-hardness difference. Data were analyzed using the Paired Sample-t and Two-ways ANOVA tests at P=0.05.
Overall, the mean dentine's micro-hardness after-irrigation (103.1) was lower than before-irrigation (116.1) (P<0.001); except for the distilled-water group, (116.6 and 112.9, respectively) (P=0.075). The micro-hardness reduction of SH without laser-activation group (32.5) was the greatest (P<0.001). The single-irrigant or laser-activation irrigation protocols caused significantly less micro-hardness reduction compared to the two-irrigants or no laser-activation protocols. The mean micro-hardness reduction of SH and MTAD groups (both with laser-activation) (5.8 and 9.3, respectively) were significantly lower than other groups, but not from that of the control group (3.7).
Using irrigants significantly reduced the root-dentine's micro-hardness. Although irrigants agitation by an Er: Yag laser significantly minimized micro-hardness reduction, it did not suppress the adverse effects on dentine micro-hardness when two-irrigants were used.
比较不同冲洗方案（有无激光激活）对根管牙本质显微硬度的影响。
82颗拔除的人类前磨牙去除冠部后分为7组。将牙根纵向劈成两半。在冲洗方案前后分别测量其中一半的显微硬度。分组如下：G1：未用激光激活的MTAD；G2：用激光激活的MTAD；G3：用激光激活的次氯酸钠（SH）；G4：先用SH然后用激光激活的乙二胺四乙酸（EDTA）；G5：先用SH然后用激光激活的MTAD；G6：未用激光激活的SH。G7：蒸馏水（对照组）。在两组冲洗剂组（G4和G5）中，样本先用SH冲洗，然后用MTAD或EDTA冲洗剂冲洗，并用激光激活。计算冲洗前后显微硬度的差值以获得显微硬度差异。使用配对样本t检验和双向方差分析在P = 0.05水平分析数据。
总体而言，冲洗后牙本质的平均显微硬度（103.1）低于冲洗前（116.1）（P < 0.001）；除蒸馏水组外（分别为116.6和112.9）（P = 0.075）。未用激光激活的SH组的显微硬度降低（32.5）最大（P < 0.001）。与两组冲洗剂或未用激光激活的方案相比，单冲洗剂或激光激活冲洗方案导致的显微硬度降低明显更少。SH和MTAD组（均用激光激活）的平均显微硬度降低（分别为5.8和9.3）明显低于其他组，但与对照组（3.7）无差异。
使用冲洗剂会显著降低根管牙本质的显微硬度。虽然用铒：钇铝石榴石激光搅拌冲洗剂可显著减少显微硬度降低，但在使用两种冲洗剂时，它并未抑制对牙本质显微硬度的不良影响。
