Winik Renata, Araki Angela Toshie, Negrão José Augusto Alves, Bello-Silva Marina Stella, Lage-Marques José Luiz
Special Laboratory of Lasers in Dentistry, Center of Research, Teaching and Clinics of Laser in Dentistry.
Braz Dent J. 2006;17(4):323-7. doi: 10.1590/s0103-64402006000400011.
Apicoectomy failure is generally related to inappropriate marginal sealing of the retrocavity, which allows percolation of microorganisms and their products from root canal system to periapex. This study evaluated tubular penetration of canal sealers and marginal permeability after retrocavity irradiation with Er;Cr:YSGG laser and retrofilling with MTA or cyanoacrylate. Twenty-two single-rooted teeth were decoronated and endodontically treated, their apical 3 mm were resected and the root ends were retroprepared with a low-speed bur. Twenty roots were randomly assigned to 4 groups (n=5): GI and GII--retrofilling with MTA and cyanoacrylate, respectively; GIII and GIV--retrocavity irradiation with Er;Cr:YSGG laser (2.78 microm, 4 W, 20 Hz, 70.8 J/cm(2)) and retrofilling with MTA and cyanoacrylate, respectively. The remaining 2 roots served as positive and negative controls. The analysis of rhodamine B dye infiltration (p=0.05) demonstrated that laser irradiation and MTA retrofilling presented significantly higher permeability rates (p<0.05). Retrofilling with cyanoacrylate showed significantly lower permeability, either when laser was used or not on retrocavity. SEM analysis depicted more cyanoacrylate penetration through dentinal tubules when compared to MTA, suggesting a more efficient marginal sealing. Based on these results, it may be concluded that cyanoacrylate provided a less permeable retrofilling regardless of the retropreparation method, suggesting a more favorable condition to the establishment of the periapical healing.
根尖切除术失败通常与倒充填腔边缘封闭不当有关，这会使微生物及其产物从根管系统渗入根尖周组织。本研究评估了用铒铬：钇-钪-镓石榴石（Er;Cr:YSGG）激光照射倒充填腔并分别用矿物三氧化物凝聚体（MTA）或氰基丙烯酸酯进行倒充填后根管封闭剂的根管渗透及边缘渗透性。22颗单根牙去冠后进行根管治疗，切除根尖3mm，用低速车针预备根端。将20个牙根随机分为4组（n = 5）：GI组和GII组分别用MTA和氰基丙烯酸酯进行倒充填；GIII组和GIV组先用Er;Cr:YSGG激光（2.78微米，4W，20Hz，70.8J/cm²）照射倒充填腔，然后分别用MTA和氰基丙烯酸酯进行倒充填。其余2个牙根作为阳性和阴性对照。罗丹明B染料渗透分析（p = 0.05）表明，激光照射和MTA倒充填的渗透率显著更高（p < 0.05）。无论倒充填腔是否使用激光，用氰基丙烯酸酯进行倒充填的渗透率均显著更低。扫描电子显微镜（SEM）分析显示，与MTA相比，氰基丙烯酸酯通过牙本质小管的渗透更多，表明边缘封闭更有效。基于这些结果，可以得出结论，无论采用何种倒充填预备方法，氰基丙烯酸酯提供的倒充填物渗透性更低，这表明对根尖周愈合的建立更有利。
