Post-operative symptoms and healing after endodontic treatment of infected teeth using pulsed Nd: YAG laser

Abstract— Forty-four teeth in 38 patients, diagnosed with chronic apical periodontitis, were endodontically treated. Root canals were shaped using a step-back technique with 5% NaOCl and 3% H₂O₂ as irrigants. In half of the teeth the canal terminus was irradiated with pulsed Nd:YAG laser (1 W, 15 pps, 1 s). All canals were then obturated with laterally condensed gutta-percha points and sealer, and final radiographs were obtained. Occurrence of spontaneous pain was recorded 1 day after treatment. Percussion pain was recorded after 1 week, and then at 3 and 6 months after treatment. Radiographic follow-up was performed at 3 and 6 months. Percussion pain was significantly less ( P >0.05) in the laser-treated group than in the control group, both 1 week and 3 months after treatment. Other differences between the groups were not significant. These results suggested that the clinical application of pulsed Nd: YAG laser might be advantageous for the treatment of infected root canals.     

脉冲Nd:YAG激光治疗慢性根尖周炎的临床疗效评价

目的 分析脉冲激光治疗慢性根尖周炎的临床疗效.方法 收集门诊68例慢性根尖周炎患者.其中36例常规根管预备后,采用激光辅助治疗和根向激光直接治疗的方法,另外32例则采用常规根管治疗做对照.通过患牙松动度、窦道愈合程度、咀嚼功能以及X线片骨质阴影区评价两者疗效.结果 激光治疗后有效率是88.89%,而常规根管治疗法则为62.50%.结论 脉冲激光对治疗慢性根尖周炎症有辅助作用,可以作为常规根管治疗的辅助手段.     

2种方法联合治疗牙本质敏感症的临床研究

目的研究奥威尔脱敏糊剂和Nd:YAG激光以及它们联合作用在治疗牙本质敏感症中的作用。方法选择40例患者,共207颗患牙,分别进入空白组、奥威尔组、激光组、奥威尔+激光组联合组,每组10例患者。采用数字化疼痛评判法记录患者在治疗前、治疗后30 min、1周、6个月时的敏感程度。结果奥威尔组在治疗后30 min和1周时脱敏效果最明显,而激光组在治疗1周和6个月后效果明显。联合组在治疗后每个时间点效果均显著。空白对照组未发现明显改变。结论奥威尔和激光治疗均能对牙本质敏感症产生明显疗效。如果两者结合,效果会更好。     

脉冲Nd:YAG激光辅助极固宁脱敏剂治疗老年牙本质过敏症的临床研究

目的：研究脉冲Nd：YAG激光辅助极固宁脱敏剂治疗老年牙本质过敏症的临床效果。方法：实验组用脉冲Nd：YAG激光1W（30mJ／cm^2、15Hz）照射120sec后，涂擦极固宁脱敏剂3次;对照组强采用极固宁脱敏剂3次。结果：实验组即刻、3个月及6个月有效率分别为87．29％、81．36％和75．42％，对照组的有效率为79．09％、63．64％和52．73％。即刻两组差异无屁著性（P〉0．05），而3个月、6个月差异有显著性（P〈0．01）。结论：脉冲Nd：YAG激光辅助极固宁脱敏荆治疗老年牙本质过敏症是一种高效、作用持久、使用安全的方法。     

龈下刮治和根面平整术联合Nd: YAG激光治疗慢性牙周炎的疗效评价

目的 研究龈下刮治和根面平整术（SRP）联合Nd: YAG激光治疗对慢性牙周炎患者的疗效。方法 选择口内有4颗及以上牙齿,探诊深度为4~8 mm的慢性牙周炎患者,研究位点为分布在口内4个不同象限的互不毗邻的单根牙。随机分成4组:对照组（不治疗）、SRP组（单纯SRP）、SRP+L组（SRP后行激光治疗）、L+SRP组（激光治疗后行SRP）。观测时间点为基线（临床处理前）和临床处理后1周、1个月、3个月,比较不同组在不同观测点牙周临床指标和龈下菌群中红色复合体（包括牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体）的组成变化。结果 牙周临床指标:SRP、SRP+L、L+SRP组的各项临床指标变化均优于对照组;3个治疗组组间比较,探诊出血、探诊深度和临床附着丧失量之间无明显差异（P>0.05）,但在3个月时,L+SRP和SRP+L组的菌斑指数百分比下降较SRP组明显（P<0.05）。微生物检测结果:SRP、SRP+L、L+SRP组龈下菌斑中牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体百分比均较基线下降,3个治疗组间也存在一定差异（P<0.05）,但在不同观测时间点的差异不完全相同。结论 慢性牙周炎治疗中,Nd: YAG激光联合SRP治疗较单纯SRP治疗未见明显优势,且Nd: YAG激光和SRP的治疗先后对临床效果也无明显影响;但激光联合SRP治疗可能较单纯SRP更有利于局部菌斑的控制。     

牙周牙髓联合病变激光与药物辅助治疗观察及菌群分析

目的:探讨双波长激光对比盐酸米诺环素治疗牙周牙髓联合病变的差别及牙周袋菌群分析。方法:收集牙周牙髓联合病变患者60颗患牙,随机分为2组:实验组Nd:YAG消毒根管一次性充填根管+Er: YAG处理牙周袋;对照组碘伏消毒根管一次性根管充填+盐酸米诺环素牙周袋上药。按视觉模拟评分法(visual analogue scale,VAS)观察两组治疗后1 d疼痛差异,对比两组治疗1周、2周、3周、3月、6月、1年的牙周袋深度(the depth of periodontal pocket,PD)、牙周附着水平(clinical periodontal attachment level,CAL),探诊出血指数(bleeding on probing,BOP),评价疗效。抽取两组病例各4例,并定期采集患牙牙周袋菌斑行高通量测序。结果:实验组与对照组治疗1 d疼痛有差异;不同时间点间PD、CAL静息状态下VAS评分有差别;BOP阳性位点发生率有差别。2组牙周袋菌斑多样性差异不大,以韦荣氏菌、变性链球菌、卟啉单胞菌、消化链球菌为主。结论:双波长激光联合辅助治疗牙周牙髓联合病变的效果优于盐酸米诺环素,具有较好的临床应用前景。     

Nd: YAG laser irradiation in root canal disinfection

Abstract The purpose of this study was to assess the efficacy of Nd:YAG laser irradiation in disinfecting the root canal system. Seventy-five teeth were uniformly instrumented and sterilized, and their root canals were infected for 60 min with an overnight culture of Enterococcus faecalis in Tryptic Soy Broth. The teeth were divided into 6 groups: 1 - non-infected controls; 2 - infected controls; 3 - infected, laser treated; 4 - infected, laser dummy (dye only); 5 - infected, laser dummy (dye and air-water spray); 6 - infected, NaOCl-treated (reference group). After treatment, the root canals were dried and dentinal shavings removed for a post-treatment culture. Quantitative analysis of bacteria surviving the various treatments were performed, and the bacterial counts for each group were compared. SEM analysis of teeth split longitudinally was used to illustrate the effect of treatment on the smear layer and on surface bacteria. Nd:YAG laser irradiation (group 3) significantly reduced the number of bacteria while NaOCl irrigation (group 6) effectively disinfected the canals.     

A histopathological study of the morphological changes at the apical seat and in the periapical region after irradiation with a pulsed Nd:YAG laser

In this study, the effects of pulsed Nd:YAG laser irradiation on the apical seat and periapical region of instrumented root canals were investigated. One hundred and ninety-two teeth, including incisors and molars (239 root canals), in 18 healthy adult beagle dogs were used. After extirpation of the pulp under anaesthesia, each root canal was shaped up to at least a size 40 K-file, and then laser irradiated using the following parameters: 1 W, 15 pps for 2, 3, and 4 s; 2 W, 15 pps for 2 s. The effectiveness of debris removal and carbonization on the root canal walls immediately laser irradiation were examined and inflammation of the periapical region at 1, 2, and 4 weeks after laser irradiation was examined using light microscopy. Effective debris removal was observed in most cases in the laser-treated groups and was dependent on irradiated energy. Carbonization was observed in the irradiated root canals except at the parameter of 1 W for 2 s. Periapical inflammation was observed at 1 W for 2 s to the same extent as in the control group (P > 0.01). These results suggest that the pulsed Nd:YAG laser is useful for debris removal with no adverse effects immediately after extirpation of the pulp if appropriate parameters are selected.     

脉冲Nd:YAG激光联合锶强化生物活性玻璃对牙本质过敏症的疗效评价

目的观察脉冲Nd:YAG激光联合锶强化生物活性玻璃治疗牙本质过敏症的临床效果。方法将89例患者156颗患牙随机分为3组,试验组(52颗):患牙涂锶强化生物活性玻璃并加用Nd:YAG激光照射;对照A组(49颗):仅用脉冲Nd:YAG激光照射;对照B组(55颗):仅涂抹锶强化生物活性玻璃。对比3组在治疗后即刻、1个月及3个月的疗效差异。结果3组患牙治疗后即刻疗效比较差异无显著性(P>0.05);随访1、3个月试验组总有效率优于对照A、对照B组,差异均有统计学意义(P<0.05,P<0.01),同时1个月及3个月时对照A组的有效率优于单纯生物凝胶组(P<0.05)。VAS疼痛值检测显示出不同时段试验组较两对照组治疗效果差异明显(P<0.05)。结论脉冲Nd:YAG激光联合锶强化生物活性玻璃治疗牙本质过敏症比单一的治疗方法具有更佳的临床效果。     

脉冲Nd:YAG激光根管内照射对狗牙尖周组织的影响

目的：观察脉冲Ｎｄ：ＹＡＧ激光根管内照射对狗牙尖周组织的影响。方法;组织学切片法和超薄切片法。结果;２．１Ｗ,１４０ｍＪ,１５Ｈｚ的脉冲;Ｎｄ：ＹＡＧ激光根管内照射２５ｓ,对尖周组织产生了明显的损伤,并延缓了尖周病变的愈合。１．２Ｗ,８０ｍＪ,１５Ｈｚ的脉冲Ｎｄ;ＹＡＧ激光根管内照射２５ｓ,对尖周组织产生的损伤明显轻于传统根管治疗,有利于尖周病变的愈合。     

A histopathological study of the effects of pulsed Nd:YAG laser irradiation on infected root canals in dogs.

The effects of pulsed Nd:YAG laser irradiation during root canal treatment of infected teeth were investigated histopathologically in dogs. One hundred and eight teeth with a single root in 15 healthy adult beagle strain dogs were used in this study. After inducing infected teeth, each root canal was shaped with up to at least a #40 K-file; then, after coating with black ink, the canal was irradiated using the following parameters: 1 W, 30 pps, for 1 and 2 s, and 2 W, 30 pps, for 2 s. The degree of inflammation of the periapical regions at 2, 4, and 8 wk was examined histopathologically by light microscopy. Inflammation of the periapical regions in the laser-treated groups was significantly less than that in the control group at 4 and 8 wk (p < 0.05). These results suggest that pulsed Nd:YAG laser is useful for root canal treatment of infected teeth, if appropriate parameters are selected.     

Comparative Evaluation of Nd:YAG Laser and Fluoride Varnish for the Treatment of Dentinal Hypersensitivity

IntroductionVarious methods and materials are used in the treatment of dentin hypersensitivity. The aim of this randomized prospective controlled clinical trial was to evaluate and compare the desensitizing effects of the neodymium-doped yttrium aluminium garnet (Nd:YAG) laser and fluoride varnish by considering the degree of pre- and posttreatment pain, discomfort, and functional complications.MethodsTwenty patients with clinically diagnosed cervical dentin hypersensitive teeth were included and randomly allocated to either the application of fluoride varnish (group fluoride) or Nd:YAG laser (100 mJ, 20 Hz; group Nd:YAG). The assessment of pain and discomfort was performed by a visual analog scale after an air blast at baseline, immediately after treatment, and at patient visits on weeks 1, 2, 3, and 4.ResultsLaser treatment resulted in significant improvements of discomfort immediately after treatment and after 1 week. At the 2-, 3-, and 4-week examination, the discomfort in group fluoride decreased up to nearly 75% to 85% of baseline scores, whereas the effect of the laser stayed nearly unchanged. The visual analog scale scores for pain at 4 weeks examination were significantly lower in the fluoride group compared with those in the laser group (p < 0.05).ConclusionsNd:YAG laser is a suitable tool for the immediately successful reduction of dentinal hypersensitivity and has better patient satisfaction and shorter treatment time.     

17% EDTA与脉冲Nd：YAG激光去除根管壁玷污层疗效的电镜研究

目的对17%EDTA与脉冲Nd：YAG激光对根管壁玷污层清除效果进行分析与比较。方法选取30颗新鲜单根成人离体牙,根管机械预备后随机分为三组,每组10例,分别给予5.25%NaClO冲洗（对照组）、17%EDTA＋5.25%NaClO冲洗以及5.25%NaClO冲洗＋Nd：YAG激光照射处理后,电镜下观察根管侧壁玷污层去除情况。利用计算机图像分析软件计算开放牙本质小管口面积/牙本质面积比。统计学方法采用单因素方差分析,α=0.05。结果EDTA冲洗及Nd：YAG激光照射后均可使根管侧壁玷污层明显减少,但EDTA冲洗对牙本质小管口开放作用明显优于Nd：YAG激光照射组及对照组（P〈0.01）。结论17%EDTA对根管壁玷污层的清除效果优于脉冲Nd：YAG激光,适合于临床广泛应用。     

Nd:YAG激光和Er:YAG激光对根管内粪肠球菌杀灭效果的研究

［摘要］ 目的 观察Nd:YAG激光、Er:YAG激光及两者联用对根管内粪肠球菌的杀灭效果。方法 选取离体牙建立粪肠球菌感染模型,随机分为五组：A组：生理盐水组;B组：1%次氯酸钠溶液组;C组：Nd:YAG激光组;D组：Er:YAG激光组;E组：Nd:YAG激光+Er:YAG激光组。通过细菌培养和扫描电镜观察对比各组的杀菌效果。结果 细菌培养和扫描电镜结果显示：A组杀菌率最低,B组杀菌率最高,E组次高。除C组和D组间杀菌率相近外（P>0.05）,各组间均有统计学差异（P<0.05）。结论 Nd:YAG激光和Er:YAG激光均有一定的根管杀菌效果,两者联用效果更佳,可作为传统消毒方法的补充。     

激光和脱敏剂治疗牙本质敏感症的临床疗效对比

目的对比Nd：YAG激光和Gluma脱敏剂治疗牙本质敏感症的临床疗效。方法 20例牙本质敏感症患者,两例对称的同名患牙分别随机分到激光组和Gluma组。激光组选用的参数为120 mJ,5 Hz,照射时间1 min,Gluma组药物涂擦时间为2 min。记录患者在治疗后即刻、术后1周、术后1个月对探针和气流刺激的视觉模拟评分（visual analogue scale,VAS）。结果术后即刻激光组、Gluma组VAS分别为4.05±0.95、4.75±1.33（P〉0.05）,术后1周激光组、Gluma组VAS分别为3.10±0.91、3.70±1.03（P〉0.05）,提示短期内激光和Gluma对牙本质敏感症的疗效无差异。术后1个月激光组、Gluma组的VAS分别为2.35±0.75、3.20±0.83（P〈0.01）,提示随着时间延长,激光照射可以显著缓解患者的牙本质敏感症状。结论 Nd：YAG激光（120 mJ,5 Hz）照射1 min与脱敏剂Gluma涂擦2 min相比,脱敏效果1周内两者无差异,术后1个月疗效以激光为优。     

The sealing ability of an epoxy resin root canal sealer after Nd:YAG laser irradiation of the root canal

AIM: To evaluate ex vivo the effect of Nd:YAG laser irradiation with and without black ink on instrumented root canal walls, and the degree of both coronal and apical microleakage of filled root canals. METHODOLOGY: Seventy-two single-rooted teeth were instrumented up to a size 40 K-file, and then divided into six groups of 10 teeth: groups 1 and 4 remained unlased and acted as control groups, groups 2 and 5 were treated with a Nd:YAG laser (Fidelis Plus, Herzele, Belgium), groups 3 and 6 were treated with a laser and black ink; the remaining 12 teeth served as positive and negative controls. The laser was operated at 1.5 W, 15 Hz, four times for 5 s with a 20-s interval. Groups 4-6 were filled using cold lateral condensation of gutta-percha and AH26. After storage in water for 48 h at 37 degrees C, through-and-through leakage (L in microL day-1) was measured for 48 h under a pressure of 1.2 atm using a fluid transport model and recorded as L=0 (L1), 010 (L3). After the assessment of leakage with the fluid transport model, the teeth were immersed in rhodamine B solution for 48 h at 37 degrees C. Apical and coronal dye leakage was scored after longitudinal splitting of these teeth. All teeth of groups 1-3 were split longitudinally and observed under SEM for evaluation of remaining smear layer. RESULTS: Through-and-through leakage was only observed in the group lased with black ink (two samples-L2). Apical and coronal dye leakage was observed in all groups; there were no statistically significant differences amongst the three experimental groups. The through-and-through leakage, measured with the fluid transport model in two teeth of group 6, was confirmed in the dye leakage test (rhodamine B dye was observed along the total length of the root filling). There was evidence of melted and ablated root canal dentine in the laser-treated groups. These findings were more obvious in root canals lased in association with black ink. All apical foramina in the lased group remained patent. CONCLUSIONS: Nd:YAG laser irradiation with black ink increased the amount of melted and ablated dentine areas compared with that without black ink. Nd:YAG lasing in association with black ink did not result in a reduction of either coronal or apical microleakage in root filled teeth.     

Nd:YAG激光治疗牙本质过敏症的临床疗效观察

目的 :探讨Nd :YAG激光治疗牙本质过敏症的疗效。方法 :15 3例患者的 2 70颗患牙 ,随机分为 2组 ,分别用Nd :YAG激光和Gluma脱敏剂进行治疗后观察疗效。结果 :实验组治愈率为 92 .5 9% ,有效率为94.0 7% ;对照组治愈率为 49.62 % ,有效率为 71.84%。结论 :2种治疗方法的疗效有显著性差异 (P <0 .0 1) ,激光治疗牙本质过敏的效果优于Gluma脱敏剂。     

Effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals: an electrochemical study

AIM: The purpose of this laboratory study was to evaluate the effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals using an electrochemical method. METHODOLOGY: Forty extracted single-rooted teeth were selected and the anatomic crown of each tooth was removed. The specimens were randomly divided into four groups. In group 1, the root canals were prepared with K-files and irradiated with Nd:YAG laser (5 W, 20 Hz) via a 300 microns optical fibre. Then the root canals were obturated with laterally condensed gutta-percha and Pulp Canal Sealer EWT. In group 2, the root canals were treated with the same method as those of group 1 but without laser irradiation. In group 3, the root canals were prepared with ProFiles, laser irradiated and then obturated with vertically condensed gutta-percha and Pulp Canal Sealer EWT. In group 4, the root canals were treated with the same method as those of group 3 but without laser irradiation. The electric resistance between standard and experimental electrodes in the canals was measured over a period of 10 days. RESULTS: At 2 h, groups 1 and 3 irradiated with laser had significantly less apical leakage than group 2 (P < 0.05). After 10 days, group 4 had the highest leakage, followed by groups 2, 1 and 3; the differences between the groups was statistically significant (P < 0.05). CONCLUSIONS: Laser irradiation following root canal preparation reduced apical leakage following root canal obturation.     

根管治疗中应用Nd:YAG 激光的扫描电镜观察

目的 探讨Nd：YAG激光在根管治疗中的应用。方法 选用28个离体单根牙，随机分为4组。对照组不做处理。常规组进行根管扩大和根管冲洗，激光组经根管扩大后，用Nd：YAG激光1．5W，20pps分别照射15s和30s，并用扫描电镜观察。结果 激光照射15s组玷污层被去除，牙本质小管封闭和半封闭。激光照射30s组牙本质过分熔融，牙本质小管口开放。结论 Nd：YAG激光在根管治疗中的应用是可行的。     

Effects of pulsed Nd:YAG laser irradiation on smear layer at the apical stop and apical leakage after obturation

AIM: This study evaluated the removal of smear layer at the apical stop by pulsed Nd:YAG laser irradiation with or without black ink, and the degree of apical leakage after obturation in vitro. METHODOLOGY: Sixty extracted human single-rooted teeth were used in this study. The teeth were instrumented up to a size 40 K-file, and then divided into three groups of 20 teeth each: group 1 was unlased as a control group; group 2 was treated with a laser; group 3 was treated with a laser and black ink. The laser was operated at 2 W and 20 pp for 2 s, and irradiation was performed twice with a 30-s interval. In each group, 10 teeth for the leakage study were obturated and immersed in rhodamine B solution for 48 h at 37 degrees C, and the others were used for evaluation of remaining smear layer. All teeth were bisected longitudinally and observed by stereoscopy or scanning electron microscopy. RESULTS: The smear layer in the laser-treated groups almost melted or evaporated, and was removed significantly compared with the control group (P < 0.05). Leakage was observed in 60% of samples in group 1 and in 20% of samples in group 2. No leakage was observed in group 3, which was significantly different from the control (P < 0.05). CONCLUSIONS: These results suggest that pulsed Nd:YAG laser irradiation with black ink increases the removal of smear layer compared with that without black ink, and reduces apical leakage after obturation significantly.