title: Systematic review of treatment modalities for gingival depigmentation: a random-effects poisson regression analysis.
abstract: OBJECTIVE
  Repigmentation variably occurs with different treatment methods in patients with gingival pigmentation. A systemic review was conducted of various treatment modalities for eliminating melanin pigmentation of the gingiva, comprising bur abrasion, scalpel surgery, cryosurgery, electrosurgery, gingival grafts, and laser techniques, to compare the recurrence rates (Rrs) of these treatment procedures.
  
  
  METHODS
  Electronic databases, including PubMed, Web of Science, Google, and Medline were comprehensively searched, and manual searches were conducted for studies published from January 1951 to June 2013. After applying inclusion and exclusion criteria, the final list of articles was reviewed in depth to achieve the objectives of this review. A Poisson regression was used to analyze the outcome of depigmentation using the various treatment methods.
  
  
  RESULTS
  The systematic review was based on case reports mainly. In total, 61 eligible publications met the defined criteria. The various therapeutic procedures showed variable clinical results with a wide range of Rrs. A random-effects Poisson regression showed that cryosurgery (Rr = 0.32%), electrosurgery (Rr = 0.74%), and laser depigmentation (Rr = 1.16%) yielded superior result, whereas bur abrasion yielded the highest Rr (8.89%).
  
  
  CONCLUSIONS
  Within the limit of the sampling level, the present evidence-based results show that cryosurgery exhibits the optimal predictability for depigmentation of the gingiva among all procedures examined, followed by electrosurgery and laser techniques.
  
  
  CONCLUSIONS
  It is possible to treat melanin pigmentation of the gingiva with various methods and prevent repigmentation. Among those treatment modalities, cryosurgery, electrosurgery, and laser surgery appear to be the best choices for treating gingival pigmentation.
authors.affiliation: Division of Periodontics, Department of Dentistry, Changhua Christian Hospital, Changhua, Taiwan.
authors.forename: Yi Hung
authors.initials: YH
authors.lastname: Lin
authors.forename: Yu Kang
authors.initials: YK
authors.lastname: Tu
authors.forename: Chun Tai
authors.initials: CT
authors.lastname: Lu
authors.forename: Wen Chen
authors.initials: WC
authors.lastname: Chung
authors.forename: Chiung Fang
authors.initials: CF
authors.lastname: Huang
authors.forename: Mao Suan
authors.initials: MS
authors.lastname: Huang
authors.forename: Hsein Kun
authors.initials: HK
authors.lastname: Lu
mesh_terms: D003452:Cryosurgery / Q000379:methods; D004598:Electrosurgery / Q000379:methods; D005881:Gingiva / Q000637:transplantation; D005882:Gingival Diseases / Q000601:surgery*; D006801:Humans; D017495:Hyperpigmentation / Q000601:surgery*; D053685:Laser Therapy / Q000379:methods; D016012:Poisson Distribution; D012008:Recurrence; D016896:Treatment Outcome