Yammine Salwa, Jabbour Edgard, El Toum Sami, Cassia Antoine
Department of Restorative Dentistry and Endodontic, Faculty of Dentistry, Lebanese University, Beirut, Lebanon.
Department of Oral Medicine and Maxillofacial Radiology, Faculty of Dentistry, Lebanese University, Beirut, Lebanon.
Scientifica (Cairo). 2018 May 2;2018:2691942. doi: 10.1155/2018/2691942. eCollection 2018.
Diode lasers have multiple indications in everyday dental practice. They allow carrying out incisions, coagulation of soft tissue, and Low-Level Laser Therapy. The goal of this study is to compare histologically the tissue interaction zones and edges of an induced laser incision on rabbits' tongues with three different wavelengths of 810, 940, and 980 nm in continuous mode.
Fourteen male rabbits were divided into six groups. Each animal underwent three incisions of 10 mm length on the right ventral face of the tongue, carried out in continuous mode with three diode lasers with different wavelengths of 810, 940, and 980 nm. Rabbits were sacrificed at 0, 1, 2, 6, and 15 hours and 14 days. Five rabbits were sacrificed at 0 hours and 2 hours and one rabbit was sacrificed at 1, 6, and 15 hours and at 14 days. The appearance of neutrophils marked the onset time of the inflammatory reaction. Histological study of the incisions was chosen to evaluate the edges and to measure the depth and width of carbonization and necrotic and inflammatory zones. Healing was evaluated at 14 days. Friedman test was used to assess statistical differences between groups.
In the experimental adopted conditions, the carbonization zone was marked by degradation of vacuoles and an elongation of nuclei and was observed on the edges of incisions. Carbonization and necrotic and inflammatory zones were measured for rabbits sacrificed at 0, 1, 2, 6, and 15 hours but the onset of inflammation zone marked by the infiltration of neutrophils did not appear before 6 hours. The neutrophils infiltration was higher at 15 hours than at 6 hours. Complete healing was shown at 14 days. According to the time for the regularity of the edges, the interpretation was qualitative without a statistical test. The statistical analysis of the three different diode lasers in this study showed nonsignificant difference between the different groups for the depth ( = 0.121) and width ( = 0.376) of the incisions, the carbonization zone ( = 0.692), and the necrotic zone ( = 0.223). For the inflammation zone at 6 and 15 hours, statistical analysis was not carried out; only one rabbit was enough to evaluate onset of neutrophils infiltration and to compare its density for 6 and 15 hours.
These results indicate that diode laser used in the continuous mode is predictable for induced incision. The use of three diode lasers with different wavelengths of 810, 940, and 980 nm did not reveal a significant statistical difference according to depth and width of the incision and for carbonization and necrotic zone. The appearance of neutrophils was marked between 4 and 6 hours and was higher at 15 hours.
二极管激光在日常牙科实践中有多种应用。它们可用于进行切口、软组织凝固以及低强度激光治疗。本研究的目的是通过组织学方法比较在连续模式下使用810、940和980 nm三种不同波长的二极管激光对兔舌进行诱导激光切口后的组织相互作用区域和边缘情况。
将14只雄性兔分为6组。每只动物在舌右侧腹面进行3次长度为10 mm的切口，使用三种不同波长（810、940和980 nm）的二极管激光以连续模式进行操作。在0、1、2、6、15小时以及14天时处死兔子。0小时和2小时处死5只兔子，1、6、15小时以及14天时各处死1只兔子。中性粒细胞的出现标志着炎症反应的起始时间。选择对切口进行组织学研究以评估边缘情况，并测量碳化、坏死和炎症区域的深度及宽度。在14天时评估愈合情况。采用Friedman检验评估组间的统计学差异。
在采用的实验条件下，碳化区域表现为空泡降解和细胞核伸长，在切口边缘可见。对在0、1、2、6和15小时处死的兔子测量了碳化、坏死和炎症区域，但以中性粒细胞浸润为标志的炎症区域在6小时之前未出现。中性粒细胞浸润在15小时时高于6小时。14天时显示完全愈合。根据边缘的规则性时间进行的解读是定性的，未进行统计学检验。本研究中对三种不同二极管激光的统计分析表明，不同组在切口深度（P = 0.121）、宽度（P = 0.376）、碳化区域（P = 0.692）和坏死区域（P = 0.223）方面无显著差异。对于6小时和15小时的炎症区域，未进行统计分析；仅1只兔子就足以评估中性粒细胞浸润的起始情况并比较其在6小时和15小时时的密度。
这些结果表明，连续模式下使用的二极管激光用于诱导切口具有可预测性。使用810、940和980 nm三种不同波长的二极管激光，在切口深度和宽度以及碳化和坏死区域方面未显示出显著的统计学差异。中性粒细胞在4至6小时之间出现，15小时时数量更多。
