The Study Of The Er:YAG Laser In The Second Phase Of Implant Surgery

In recent years,laser has been widely used in oral and maxillofacial soft tissue surger-y,such as the treatment of labial(lingual)frenectomy,mucocele,epulis,hemangioma,leukoplakia,etc.The control of thermal effect soft tissue has always been the focus.Which wavelength laser to use,how,to control the parameters of laser is currently.a controv ersial issue.In addition,laser is also rapidly developing in the field of implantation.Regardless of the preparation of implant site,implant surgery,treatment of peri-implantitis,lasers have played a huge advantage.The purpose of this study was to conform the saf-ety and efficacy of Er:YAG laser in the clinical application of stage II surgery.of implanta-tion.This paper consists of three parts.The first part and the second part are in vitro experiments,which show the safety of Er:YAG laser in soft tissue cutting and implant surf-ace.The third part is to compare the clinical effects of Er:YAG laser and traditional scalpel in the stage II surgery of implantation.In order to provide information for clinical application.Part ? Laser-assisted surgery with different wavelengths on soft tissue:a preliminary in vitro study on thermal increase and histological evaluationBackground:Lasers have become standard tools for the surgical treatment of oral lesions.The purpose of this study is to compare different laser wavelengths in relation to both thermal increase and "histologist quality" in a model of soft surgery procedures.Material and Methods:Cuts were made in goat tongues'mucosa with different lasers(Er:YAG at 2W without air/water spray and at 4W without air/water spray;Diode at 3W an-d in continuous mode and at 5W in continuous mode;Nd:YAG at 3W and 5W in pulsed mode and conventional scalpel as control.Thermal evaluation was realized by a therm-ocouple to evaluate thermal increase on the depth of the specimen,Macroscopic and microscopic morphological changes were evaluated.Results:Temperature elevation:The increase of temperature in depth was more consistent for diode and Nd:YAG laser,with increase between 10°Cand 16°Cand less important for Er:YAG laser,with an increase between 2? and 6?.Statistical analysis retrieved a significant result(P<0.05).Macroscopic and microscopic elevation:The results of this study showed that the surgical instruments that caused greater tissue damage extension were:the diode laser 5W CW(607.62?m),the Nd:YAG 5W PW(574.72?n),the Diode laser 3W CW(513.36?m),the Nd:YAG 3W PW(421.53?m),Er:YAG 4W(92.27?m)laser and Er:YAG 2W(82.35?m)laser,regardless of power,mode or air/water spray used.An positive asso-ciation between the Extent of Thermal Tissue Damage and the Degree of Carbonizat-ion,and an negative association between the Extent of Thermal Tissue Damage and Regu-larity of the incision were found.Conclusion:1.The Er:YAG laser was the device with a lower influence on thermal increase which had the best quality of incision.2.The Nd:YAG laser and the Diode laser caused greater tissue carbonization.Part ? Morphological Changes of Titanium Surface after Er:YAG Laser and Nd:YAG Laser IrradiationBackground:To evaluate the morphological changes of the titanium surface after irradia-tion with the Er:YAG Laser and Nd:YAG Laser at various energiesMaterial and Methods:There are 9 SLA surface treated titanium discs in total,4 tita-nium discs was set as Er:YAG laser group,and 4 titanium discs Nd:YAG laser group,andl titanium discs was set blank control group.Er:YAG laser components A1,A2,A3,A4 four subgroups,using R14 hand tools,set the MSP irradiation mode,the frequency is 20Hz,the irradiation power is A1 group 40mJ,A2 group 70mJ,A3 group 100mJ,A4 group 150mJ;Nd:YAG laser components B1,B2,B3,B4 four subgroups,using MSP mode,the frequency is 15Hz,fiber is 300um,irradiation power is B1 group 1W,B2 group 1.5W,B3 gr-oup 2W,B4 Group 3W.The blank control set a piece of titanium.Laser irradiation:The tip of the fiber is 1 mm away from the surface of the titanium disc,the surface of each disc was treated at 45°and moved at a speed of 2 mm/s.after irradiation,the surfaces morpho-logy of the titanium discs were analyzed by scanning electron microscopy(SEM).Results:Er:YAG laser group:In the power range(40mJ?150mJ),no significant melting,condensation and other changes occurred on the surface of the titanium disc.Nd:YAG laser group:Scanning electron microscopy observation shows that when the power is higher than 1.5W,the surface of the titanium disc shows melting,condensation and micro-cracks.The degree of change is proportional to the power output.Conclusion:Er:YAG laser with power lower than 150mJ and Nd:YAG laser with power lower than 1W have no obvious effect on the surface morphology of SLA-treated titanium disc.When the power of Nd:YAG laser is above 1.5W,the surface of titanium disc appea-red melting,condensation and microcracks.The scale of damage is proportional to the po-wer output.Part ? The clinical comparative study of the Er:YAG laser and traditional scalpel in the second phase of implant surgeryBackground:This study was aimed to compare the efficacy and soft tissue wound healing using Er:YAG laser and conventional scalpel in the second stage of implant surgery.Materials and Methods:Forty patients were studied with a total of 64 implants in which osseointe-gration was complete.The subjects were divided into 2 groups:A group(20 patients with 33 implants),subjected to Er:YAG laser at second-stage implant surgery;and B group of 20 subjects(with 31 implants)treated with conventional second-stage surgery.To evaluate the influence of different methods on soft tissue healing.Clinical parameters such as need and amount of local anesthesia,duration of surgery,intraoperative bleeding,pain index(NRS),wound healing index(HI),and time for impression taking were recorded at various intervals.Results:1.The average duration for Group A(Er:YAG laser was found to 8.6±2.02 min,and for Group B was found to 10.1±2.55 min.The operation time of group A was lower than that of group B(P = 0.013<0.05).2.The patients who needed local infiltration anesthesia in group A(24.2%)were significantly lower than those in group B(100%).The average dosage of local infiltration anesthetics(0.3 ml)was significantly lower than that in traditional scalpel group(1.1 ml).The difference between the two groups was statistically significant(P<0.05).3.The amount of bleeding during operation in group A was significantly lower than that in group B,and the difference was statistically significant(P<0.05).4.The NRS score of pain degree in group A was higher than that in group B on the first day and the third day after operation(P<0.05),but there was no significant difference between the two groups on the 7th day after operation(P>0.05).5.The average time for impression taking in group A and B was found to be 7.2±0.48 and 12.6±1.25days,respectively.The difference between group A and group B was statistically significant(P<0.05).6.Intergroup comparison of HI among Group A and Gronp B was done using Chi-square test.Significant difference were found between two group(P<0.05)Conclusion:The advantages afforded by Er:YAG laser treatment include technical simplicity,the possibility of obviating local anesthesia,absence of postoperative pain and edema,and thus facilitating rapid prosthetic rehabilitation.