Clinical Experimental Study On The Combined Treatment Of Chronic Periodontitis With Er:YAG Laser And Nd:YAG Laser

Objective:The application of Er:YAG laser and Nd:YAG laser in periodontal treatment is currently gaining widespread attention.The present study aims to investigate the clinical effectiveness of the combined Er:YAG laser and Nd:YAG laser in the treatment of chronic periodontitis in comparison with SRP,to establish scientific and reliable theoretical support for the combined treatment of chronic periodontitis with Er:YAG laser and Nd:YAG laser,and to provide guidance for the application and promotion of this treatment modality in clinical practice.Method:Thirty selected patients with chronic periodontitis were included in this research.A split-mouth design was used,with the left and right quadrants randomly assigned to one treatment group.Laser group: Er:YAG laser(Energy: 50 m J,Frequency: 15 Hz,Power: 0.75 W,Water: 4,Gas: 4)+ Nd:YAG laser(Pulse width: MSP,Frequency:15Hz,Power: 1.50W),SRP group: scaling and root planing with a traditional manual subgingival scraper.Probing depth(PD)and clinical attachment level(CAL)were probed at six positions(proximal buccal,middle buccal,distal buc-cal,proximal tongue/palate,middle tongue/palate,and distal tongue/palate)for each tooth in 30 patients using periodontal probes at three time points: baseline,1 month post-treatment,and 3 months post-treatment,and gingival status and bleeding were monitored and the bleeding index(BI)was recorded for each tooth.Meanwhile,sites with PD ≥5 mm were randomly selected for subgingival plaque and gingival sulcus fluid collection in the Laser and SRP groups,respectively,and all sampling sites were kept consistent at 1 and 3 months after treatment.Absolute quantification PCR(AQ-PCR)and enzyme-linked immunosorbent assay(ELISA)were applied to measure the level of red complex in subgingival plaque and the level of cytokines in gingival sulcus fluid,respectively.Result:1.In the process of clinical parameter analysis,there was a significant improvement in all clinical parameters in both groups at 1 and 3 months post-treatment,and the mean values of PD,CAL,and BI were lower than baseline(P<0.001).However,there was no obvious decrease in PD and BI in the SRP group between 1-3 months(P>0.05).At any time point after treatment,the mean PD,CAL and BI in the Laser group decreased significantly compared to the SRP group,and there was a statistically significant difference(P<0.001).After treatment,it was observed that the gingival color changed from bright red to pink in both laser group and SRP group,the gingival color recovered,the texture changes from flimsy to ductile and the bleeding decreases.2.In the process of microbial analysis,there were no significant difference between the Laser and SRP groups in the percentages of Porphyromonas gingivalis(Pg),Treponema dentatum(Td)and Tannerella forsythia(Tf)at any point(P>0.05).The data indicated that,apart from the Laser group where the percentage of Pg decreased significantly at the 3-month follow-up(P=0.035),the percentages of Pg,Tf and Td at other time points were not significantly different from baseline(P>0.05).3.In the process of inflammatory mediatore analysis,interleukin-1β(IL-1β)levels were significantly lower in both groups than before treatment at all time points after treatment(P<0.001),but IL-1β levels did not significantly change 1-3 months after treatment in either group.(P>0.05).At 1 and 3 months of follow-up,no statistical meaningful comparison of IL-1b levels between the Laser and SRP groups(P>0.05).The intra-group comparison between the two groups at any post-treatment time point was statistically validated(P<0.001),except for a non-significant decrease in matrix metalloproteinase 8(MMP-8)levels at 1-3 months in the SRP group(P>0.05).In addition,at 3 months after treatment MMP-8 levels were markedly lower in the Laser group than in the SRP group(P<0.001).Conclusion:1.Co-operative therapy of chronic periodontitis with Er:YAG and Nd:YAG lasers has a positive effect on improving clinical symptoms,reducing probe depth,clinical attachment level and bleeding index compared with SRP.2.Co-operative therapy of chronic periodontitis with Er:YAG and Nd:YAG lasers for chronic periodontitis has a bactericidal effect on Pg.3.Co-operative therapy of chronic periodontitis with Er:YAG and Nd:YAG lasers can significantly reduce the MMP-8 level and improve the inflammation control compared with SRP.This study confirmed that the combination of Er:YAG laser and Nd:YAG laser is effective in the treatment of chronic periodontitis.The combined application of Er:YAG laser and Nd:YAG laser can be a new therapeutic method for chronic periodontitis and be widely used in clinic.