The Application Of Er:YAG Laser And Nd:YAG Laser In Implantation

Objective:The purpose of this study is to explore the application of Er:YAG laser and Nd:YAG laser in implant surgery and observe the promotion of tissue repair around the implant through in vivo experiments.To provide scientific basis and theoretical guidance for the more effective application of Er:YAG laser and Nd:YAG laser in implantations.Methods:In this study,the rabbit experimental model of femoral defect implant implantation was used to simulate the process of bone repair and tissue reconstruction around the human implant.Thirty-six experimental rabbits were selected and divided into four groups: Er:YAG laser group,Nd:YAG laser group,Er:YAG laser group combined with Nd:YAG laser group（combined group）and the control group.The rabbits were implanted with an implant at the proximal end of the femur.The animals were sacrificed on days 3,7 and 14,respectively.The femoral tissue 3mm around the implant was collected and fixed in 4% paraformaldehyde for 48 hours before removal.Micro-CT scanning analysis was performed on the implant and the surrounding bone tissues to obtain data including bone density（BMD,g/cm 3）,trabecular thickness（Tb.Th,mm）,trabecular resolution（Tb.Sp,mm）and trabecular count（Tb.N,1/mm）.Micro-CT can be used to observe the bone density of bone tissue around the implant and the resolution of trabecular bone to quantitatively analyze the repair of bone tissue around the implant.The implant and part of the surrounding bone tissue were embedded with methyl methacrylate,cut into hard tissues and stained with VG.The physiological gap between the implant and bone tissue was observed through the sections stained with VG for the hard tissues.Then,some bone tissues around the implant were decalcified in 7% EDTA,and the decalcified tissue mass was embedded in paraffin and sectioned for HE staining.The effect of bone repair was qualitatively analyzed by observing the thickness of trabecular bone around the implant and whether there was inflammatory tissue around in the sections stained with hematoxylin and eosin.The paraffin sections of some bone tissues around the implant were marked with osteocalcin and vascular endothelial growth factor by immunohistochemistry,and the positive expression of OCN and VEGF was observed to quantitatively analyze the effect of bone integration.Image Pro Plus 6.0,SPSS 19.0and Prism statistical software were used for data processing and analysis.Result:1.Bone samples with implants were obtained by Micro-CT bone tissue scanning on days 3,7 and 14 after operation.The Tb.sp values of the Er: YAG laser group and the Nd: YAG laser group were lower than those of the control group on days 3 and 7after operation,and the Tb.Sp value of the Er: YAG laser group was slightly lower than that of the Nd: YAG laser group.The Tb.sp values of each time period in the combination group were significantly lower than those in the Er:YAG laser group,the Nd:YAG laser group,and the control group.Three days after surgery,the difference in BMD values between the Er: YAG laser group and the Nd: YAG laser group was not significant and the efficacy of the combination group was significantly superior to that of the other groups.Seven days after surgery,the BMD value of the Er:YAG laser group was significantly superior to that of the Nd:YAG laser group,and the BMD value of the combination group was the highest.The BMD of the combined group was 0.16±0.01（g/cm）14 days after surgery,which was significantly superior to those of the Er:YAG laser group,the Nd:YAG laser group,and the control group.As a whole,the bone mineral density,the number of trabeculae,and the thickness of trabeculae in the combination group at different time points were significantly superior to those in the single laser group and the control group.2.VG staining of the hard tissues of the implant and bone tissue was observed and calculated.On day 14 after operation,the average proportions of new bone tissue areas in the Er:YAG laser group,the Nd:YAG laser group,the combination group and the control group were 57.08%,52.73%,70.16% and 40.47%,respectively.There was no obvious physiological gap between the implant and the surrounding bone tissue in the combination group,and the bone repair rate was the highest.At the same time,the bone integration efficiency of Er:YAG laser group was superior to that of Nd:YAG laser group.At the same time,the HE staining sections of the femoral samples at the 3rd and7 th day after operation were analyzed by Image Pro Plus 6.0 image analysis and processing software.It can be seen that the average trabecular width of the combination group was significantly higher than that of the Er:YAG laser group,the Nd:YAG laser group and the control group in all time periods.As a whole,the trabecular area and trabecular width in the combined group were higher than those in the single laser group and the control group.The inflammatory cell infiltration was small,and the bone trabeculae were densely arranged.There were more new bone trabeculae and a large number of osteoblasts were surrounded around them.3.The OCN positive expression in the Er:YAG laser group was significantly greater than that in the Nd:YAG laser group and the control group 3 and 7 days after surgery.However,the OCN positive expression in the Er:YAG laser group 14 days after surgery was similar to that in the Nd:YAG laser group.Immunohistochemical staining of OCN and VEGF showed that the percentages of OCN positive areas in the combination group were higher than those in other experimental groups and the control group at the same time point,and the percentages of VEGF positive areas in the combination group were significantly better than those in other experimental groups and the control group.The difference between different groups was statistically significant.Compared with the control group,the application of dual-wavelength laser promoted the efficiency of early peri-implant bone integration.Conclusion:The combined application of dual-wavelength laser in implantations has the best effect,and lays a theoretical foundation for the clinical application of dual-wavelength laser to promote the peripheral bone tissue.The results showed that the combination of Er:YAG laser and Nd:YAG laser had a positive effect on the early bone integration of the implant.Moreover,compared with the traditional reamer for implant surgery,Er:YAG laser and Nd:YAG laser can more significantly promote the proliferation of osteoblasts and the formation of new bone.In addition,the combination of Er:YAG laser and Nd:YAG laser significantly outperformed the laser alone and improved peri-implant bone integration by modulating the expression of OCN and VEGF.In summary,this experimental study has important clinical significance,which can provide a scientific basis for the combination of Er:YAG laser and Nd:YAG laser to promote early bone integration of bone tissues around the implant.