Application of Laser to Endodontic Micro-Surgery

1：成纤维细胞在Er：YAG激光照射牙本质表面的初始附着本研究的目的是评价酸性、低强度Er：YAG激光照射或激光照射+抗生素处理后的牙本质表面的生物相容性。将获得的牙本质盘分为激光照射组(30mJ/脉冲，10pps，60s)，L-MTAD组，激光照射+强力霉素、四环素异构体和柠檬酸混合物组，RC-Prep组，EDTA凝胶或乳膏(RC-Prep)处理组，(4)空白对照组。每次处理后，将牙本质盘与NIH/3T3成纤维细胞在添加10%胎牛血清和抗生素的Dulbecco‘s改良Eagle’s培养液中培养至亚融合。组间贴壁细胞数在5%的显着性水平进行统计学分析。牙本质…扫描电子显微镜(SEM)观察到更多的表面形貌。在细胞培养处理后的4、8和16h三个有代表性的时间点，通过计数分析、组织学观察和扫描电子显微镜对细胞贴壁进行评估。贴壁细胞数显著高于对照组(p&lt；0。05)在16h时，激光组优于RC-Prep组和对照组。扫描电子显微镜下可见8h激光照射组成纤维细胞可见树突状细胞伸展。在组织学分析中，激光照射后牙本质表面附着的细胞明显增多。2.Er：YAG和Nd：YAG激光处理牙本质表面对成纤维细胞黏附的影响本实验通过分析Er：YAG和Nd：YAG激光照射后牙本质表面的形态和粗糙度来评价成纤维细胞与牙本质表面的黏附情况，并与传统的毛刺处理结果进行比较。本研究使用35颗新鲜拔除的根尖完整的单根人类牙齿。去除每颗牙的根尖，用低速锯制作牙本质盘。牙本质盘分为三组。A组不治疗，B组用Er：YAG激光照射(60mJ/脉冲，10pps，60s)，C组用60mJ/脉冲，10pps，60s的激光照射。激光照射后，将牙本质盘与NIH/3T3成纤维细胞在Dulbecco‘s改良Eagle’s培养液中培养。扫描电子显微镜观察牙本质表面的形态结构，激光共聚焦扫描显微镜测量表面粗糙度。分别于孵育12、24小时用扫描电子显微镜分析和WST法检测细胞黏附能力。统计分析采用方差分析，显著性水平为5%(p&lt；0。05)。形态分析和粗糙度测量结果显示，Er：YAG激光照射组(B组)牙本质表面均较A、C组粗糙，培养12h后，Er：YAG照射组牙本质表面贴壁细胞扁平，并以扩张的丝状基座附着于牙本质表面。B组(Er：YAG)在12、24小时贴壁细胞数最多。较少

1 : Initial fibroblast cell attachment to Erbium : YAG laser-irradiated dentinThe purpose of this study was to evaluate the biocompatibilities of resected dentin surfaces after treatment with acid, low-level Er : YAG laser irradiation, or laser irradiation plus antibiotics. Dentin disks obtained from single-rooted human teeth were divided into the following groups :(1) Laser group, treated with Er : YAG laser irradiation(30mJ/pulse, 10pps, 60s);(2) L-MTAD group, treated with laser irradiation as in the laser group plus a mixture of doxycycline, tetracycline isomer and citric acid ;(3) RC-Prep group, treated with EDTA gel or cream(RC-Prep); and(4) Control group, left untreated. After each treatment, the dentin disks were incubated with NIH/3T3 fibroblasts cultured to subconfluency in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum and antibiotics. The number of attached cells among the groups was statistically analyzed at the 5% significance level. The dentin … More surface morphologies was observed under scanning electron microscopy(SEM). Cell attachments were evaluated at three representative time points : 4, 8, and 16h following cell culture treatment by counting assays, histological observation, and SEM. The number of attached cells was significantly higher(p<0. 05) in the Laser group than in the RC-Prep and Control groups at 16h. Dendritic cell extension of the fibroblasts was only observed in the Laser group at 8h by SEM. In the histological analyses, significantly more attached cells were found on the dentin surfaces treated with laser irradiation.2 : Effects of dentin surface modifications treated with Er : YAG and Nd : YAG laser irradiation on fibroblast cell adhesionThis in vitro study evaluated fibroblast adhesion to dentin surfaces treated with Er : YAG and Nd : YAG laser irradiation by analyzing the morphology and roughness of dentin surfaces and compared the results with those of the conventional treatment with burs. Thirty-five freshly extracted single-rooted human teeth with fully formed apices were used in this study. The root apex of each tooth was removed and dentin disks were prepared using a low-speed saw. Dentin disks were divided into three groups. Group A was left untreated, Group B was treated with Er : YAG laser irradiation(60mJ/pulse, 10 pps, 60s), and Group C was treated with Nd : YAG laser irradiation(60mJ/pulse, 10pps, 60s). After laser irradiation, the dentin disks were incubated with NIH/3T3 fibroblasts cultured in Dulbecco's modified Eagle's medium. A morphological analysis of the dentin surface was observed under SEM, and surface roughness was measured using a confocal laser scanning microscopy. Cell adhesion was evaluated at 12and 24h of incubation periods using SEM analysis and WST assay. The statistical analysis was undertaken using ANOVA at a 5% level of significance(p<0. 05). Morphological analysis and roughness measurement showed that all dentin surfaces treated with Er : YAG laser irradiation(Group B) were rougher than those in Groups A and C. In the Er : YAG-irradiated group, attached cells were flattened and attached to the dentin by expanded filopodia after 12h of culture. Group B(Er : YAG) exhibited the greatest number of attached cells among all groups after 12 and 24h. Less