Background: Several studies have described the benefits of LASER when used for crown lengthening (CL). However, there has been a lack of clinical trials comparing surgical functional crown lengthening (FCL) and LASER flapless CL. The aim of this study was to compare both methods together in terms of soft-tissue wound healing, gingival marginal stability and sub-gingival bacterial load reduction.
Subjects and methods: Twenty patients with eligible teeth for FCL were recruited and randomly allocated to either; Group I: 10 posterior teeth indicated for FCL received closed flap laser assisted CL utilizing (Er,Cr:YSGG) laser or Group II : 10 posterior teeth indicated for FCL received open flap conventional surgical technique. Soft tissue healing was evaluated on the 7th day,45th day and after 3 months. Gingival marginal stability was evaluated immediately after surgery and after 3 months.Sub-gingival bacterial load was assessed at base-line, on the 7th day and after 45 days.
Results: Group 1 showed significant better soft tissue healing after 7 days but there was no significant difference between the 2 groups after 45 days as well as after 3 months. Regarding the gingival marginal stability, there was no significant difference between both groups. There was a significant reduction in sub-gingival bacterial load in both groups, however, group 1 showed significant lower bacterial load after 7 days as well as after 45 days.

Conclusion: Closed flap laser-assisted CL using Er,Cr:YSGG laser can be used as an alternative procedure for conventional surgical FCL with better and faster healing and bacterial disinfection.