title: Influence of Soft Tissue Thickness on Peri-Implant Marginal Bone Loss: A Systematic Review and Meta-Analysis.
abstract: Multiple variables have been shown to affect early marginal bone loss (MBL). Among them, the location of the microgap with respect to the alveolar bone crest, occlusion, and use of a polished collar have traditionally been investigated as major contributory factors for this early remodeling. Recently, soft tissue thickness has also been investigated as a possible factor influencing this phenomenon. Hence, this study aims to further evaluate the influence of soft tissue thickness on early MBL around dental implants.
  
  
  
  Electronic and manual literature searches were performed by two independent reviewers in several databases, including Medline, EMBASE, and Cochrane Oral Health Group Trials Register, for articles up to May 2015 reporting soft tissue thickness at time of implant placement and MBL with ≥12-month follow-up. In addition, random effects meta-analyses of selected studies were applied to analyze the weighted mean difference (WMD) of MBL between groups of thick and thin peri-implant soft tissue. Metaregression was conducted to investigate any potential influences of confounding factors, i.e., platform switching design, cement-/screw-retained restoration, and flapped/flapless surgical techniques.
  
  
  
  Eight articles were included in the systematic review, and five were included in the quantitative synthesis and meta-analyzed to examine the influence of tissue thickness on early MBL. Meta-analysis for the comparison of MBL among selected studies showed a WMD of -0.80 mm (95% confidence interval -1.18 to -0.42 mm) (P <0.0001), favoring the thick tissue group. Metaregression of the selected studies failed to demonstrate an association among MBL and confounding factors.
  
  
  
  The current study demonstrates that implants placed with an initially thicker peri-implant soft tissue have less radiographic MBL in the short term.
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Fernando
authors.initials: F
authors.lastname: Suárez-López Del Amo
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Guo-Hao
authors.initials: GH
authors.lastname: Lin
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Alberto
authors.initials: A
authors.lastname: Monje
authors.affiliation: Department of Oral Surgery and Implant Dentistry, University of Granada, Granada, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Galindo-Moreno
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D016301:Alveolar Bone Loss; D000539:Alveolar Process; D001851:Bone Diseases, Metabolic; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D006801:Humans; D013524:Surgical Flaps
chemical_list: D015921:Dental Implants
keywords: Alveolar bone loss; dental implant-abutment design; dental implants; endosseous dental implantation; evidence-based dentistry; review, systematic