Abstract:

Abstract:Objective To study the clinical effects of high-frequency electric knife,CO₂ laser,microwave technique and conventional surgery in treating gingival hyperplasia caused by  ill porcelain-fused-to-metal (PFM) and explore the values of their chinical applications.Methods Different types and various degrees of 148 patients with gingival hyperplasia were randomly divided into  high-frequency electric knife group,microwave technique group,CO₂  laser group,and conventional surgery group,37 cases in each group.The patients were treated with the 4 kinds of methods mentioned  above.Then gingiva was removed and  its form was repaired to restore and reconstruct the periodontal physiological function and appearance.Results ①Compared with  conventional surgery group,in high-frequency electric knife,CO₂  laser,microwave technigue groups,the  operative time was shorher,the intraoperative blood loss was lower,the wound healing time was shortened,and the wound infection rates were decreased(P<0.05 or P<0.01).②The gingival indexes(GI),sulcus bleeding indexes(SBI) and modified bleeding indexes(mBI) in 4 groups after operation were significantly decreased compared with before operation(P<0.01).The GI in high-frequency electric knife group,CO₂  laser group,and microwave technique groups after operation were significntaly  lower than that in conventional surgery group (P<0.05).③ The one-year  efficiencies in high-frequency electric knife group,CO₂  laser group,and  microwave technique group were 97.3%,94.6%,and 97.3%,there were no significant differences between three groups (χ2 = 0.34,P> 0.05);but they were sifnificantly higher than that in conventional surgery group  (89.2%) (χ2 = 0.54,P<0.05).Conclusion High-frequency electric knife,CO₂ laser,and microwave technique   can be effective in the treatment of gingival hyperplasia,and superior to conventional surgery.

Key words: gingival hyperplasia;high-frequency electric knife;CO2 laser;microwave technique;gingival index;sulcus bleeding index;modified bleeding index