Franceschini Keila de Almeida, Silva-Sousa Yara Teresinha Corrêa, Lopes Fabiane Carneiro, Pereira Rodrigo Dantas, Palma-Dibb Regina Guenka, de Sousa-Neto Manoel Damião
Department of Restorative Dentistry, Shcool of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Faculty of Dentistry, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil.
Lasers Surg Med. 2016 Dec;48(10):985-994. doi: 10.1002/lsm.22496. Epub 2016 Jul 18.
The aim was to evaluate the influence of Er,Cr:YSGG laser irradiation associated with different final irrigation protocols on the bond strength of epoxy resin-based root canal sealer to root dentin, on the dentin/filling material interface and in the temperature variation during irradiation.
Ninety-six maxillary canines were prepared with K3 rotary system up to #45/0.02 instrument, irrigating with distilled water between files. The specimens were randomly assigned to three groups-final irrigation (distilled water, 1% NaOCl, and 17% EDTAC) and four subgroups (n = 8)-laser parameters (non-irradiated, 2 W/20 Hz, 3 W/20 Hz, and 4 W/20 Hz). During irradiation, the temperatures were measured on the outer root dentin wall in the three thirds, and root apex. Canals were filled with lateral condensation of AHPlus sealer and gutta-percha cones. Two slices from each third were submitted to a push-out test in Instron machine and the failure mode was analyzed. One slice from each third was analyzed by confocal laser microscopy to evaluate the percentage of the perimeter of the root canal cross-section with sealer tags and depth of tags. Data were analyzed by ANOVA, Kruskal-Wallis, and Tukey's tests (P < 0.05).
Er,Cr:YSGG laser irradiation increased sealer bond strength to dentin, regardless of the final irrigation. The highest values were obtained for 3 W (4.02 ± 1.32) and 4 W (4.18 ± 0.98) powers and different from the non-irradiated group (2.64 ± 0.58) (P < 0.05). The 2 W irradiation produced similar results to 3 W and 4 W when associated with 17% EDTA. Final irrigation with 17% EDTAC provided higher bond strength (4.01 ± 1.02) compared with distilled water (3.11 ± 1.09) and 1% NaOCl (3.47 ± 1.18) (P < 0.05). The cervical third (4.01 ± 1.21) presented significantly higher bond strength than the apical third (3.04 ± 0.89). There was a greater percentage of adhesive and mixed failure. In the groups irradiated with 3 W [21.1 (14.1-27.7)] and 4 W [17.8 (11.9-23.7)], a greater depth of filling material tags was observed compared with the non-irradiated group [12.9 (9.0-20.0)]. The greatest percentage of canal perimeter with sealer tags was observed in the irradiated groups, with no difference among them (P > 0.05). The temperature rise was proportional to the increase of laser power.
Er,Cr:YSGG laser irradiation increased the bond strength of an epoxy resin-based sealer to root dentin, with greater formation of sealer tags for all tested powers, especially when combined with 17% EDTAC final irrigation; temperature rise during irradiation remained below the critical threshold biologically accepted. Lasers Surg. Med. 48:985-994, 2016. © 2016 Wiley Periodicals, Inc.
评估铒铬：钇稳定氧化锆激光照射联合不同最终冲洗方案对环氧树脂类根管封闭剂与牙根牙本质的粘结强度、牙本质/充填材料界面以及照射过程中温度变化的影响。
使用K3旋转系统将96颗上颌尖牙预备至#45/0.02器械，每更换一支器械后用蒸馏水冲洗。将标本随机分为三组——最终冲洗（蒸馏水、1%次氯酸钠和17%乙二胺四乙酸）和四个亚组（n = 8）——激光参数（未照射、2W/20Hz、3W/20Hz和4W/20Hz）。在照射过程中，测量牙根牙本质壁外三分之一、中三分之一和根尖处的温度。根管采用侧向加压法用AHPlus封闭剂和牙胶尖充填。从每个三分之一处切取两片进行Instron机推出试验，并分析失败模式。从每个三分之一处切取一片通过共聚焦激光显微镜分析，以评估根管横截面周边有封闭剂标签的百分比和标签深度。数据采用方差分析、Kruskal-Wallis检验和Tukey检验进行分析（P < 0.05）。
无论最终冲洗方案如何，铒铬：钇稳定氧化锆激光照射均提高了封闭剂与牙本质的粘结强度。3W（4.02±1.32）和4W（4.18±0.98）功率下获得的值最高，与未照射组（2.64±0.58）不同（P < 0.05）。2W照射与17%乙二胺四乙酸联合使用时产生的结果与3W和4W相似。与蒸馏水（3.11±1.09）和1%次氯酸钠（3.47±1.18）相比，17%乙二胺四乙酸最终冲洗提供了更高的粘结强度（4.01±1.02）（P < 0.05）。颈段三分之一（4.01±1.21）的粘结强度明显高于根尖段三分之一（3.04±0.89）。粘结性和混合性失败的百分比更高。在3W[21.1（14.1 - 27.7）]和4W[17.8（11.9 - 23.7）]照射组中，与未照射组[12.9（9.0 - 20.0）]相比，观察到充填材料标签的深度更大。在照射组中观察到根管周边有封闭剂标签的百分比最大，各组之间无差异（P > 0.05）。温度升高与激光功率的增加成正比。
铒铬：钇稳定氧化锆激光照射提高了环氧树脂类封闭剂与牙根牙本质的粘结强度，在所有测试功率下均有更多封闭剂标签形成，尤其是与17%乙二胺四乙酸最终冲洗联合使用时；照射过程中的温度升高保持在生物学可接受的临界阈值以下。《激光外科与医学》48:985 - 994，2016年。©2016威利期刊公司。
