title: Excess cement and the risk of peri-implant disease - a systematic review.
abstract: OBJECTIVE
  The aim of this systematic review was to assess the role of excess cement as risk indicator for peri-implant diseases.
  
  
  METHODS
  A systematic literature search with the keywords peri-implant disease, peri-implant mucositis, peri-implantitis, excess cement, cemented, and screw-retained restorations was performed for articles published by June 2016 using MEDLINE and EMBASE electronic databases, complemented by hand searching.
  
  
  RESULTS
  The included 26 publications referring to 21 study groups were published between 1999 and 2016 and comprised 945 subjects with 1010 cemented implant restorations in 10 prospective and eight retrospective studies and eight case reports/series with pronounced heterogeneity of the study designs. Prevalence of peri-implant diseases varied between 1.9% and 75% of the implants with cemented restorations, with proportions of 33-100% associated with excess cement. In publications including early follow-ups and regular recall intervals, peri-implant disease was mostly detected at an early stage. Cofactors, such as type of abutment (standardized or individualized) and cementum medium used, did not have a significant influence, while higher prevalence of peri-implant diseases was found with immediate loading or cementation subsequent to reentry, and with cemented vs. screw-retained restorations.
  
  
  CONCLUSIONS
  Excess cement was identified as a possible risk indicator for peri-implant diseases and was more frequently observed with soft tissue healing periods shorter than 4 weeks. To reduce the risk of peri-implant disease associated with excess cement, a crown margin at the level of the mucosal margin providing sufficient access is recommendable, and soft tissue maturation and early follow-ups after restoration placement should be assured.
authors.affiliation: Department of Periodontology, Endodontology and Cariology, University Centre for Dental Medicine, University of Basel, Basel, Switzerland.
authors.forename: Noémie
authors.initials: N
authors.lastname: Staubli
authors.affiliation: Department of Periodontology, Endodontology and Cariology, University Centre for Dental Medicine, University of Basel, Basel, Switzerland.
authors.forename: Clemens
authors.initials: C
authors.lastname: Walter
authors.affiliation: Department of Periodontology, Endodontology and Cariology, University Centre for Dental Medicine, University of Basel, Basel, Switzerland.
authors.forename: Julia C
authors.initials: JC
authors.lastname: Schmidt
authors.affiliation: Department of Periodontology, Endodontology and Cariology, University Centre for Dental Medicine, University of Basel, Basel, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: Weiger
authors.affiliation: Department of Periodontology, Endodontology and Cariology, University Centre for Dental Medicine, University of Basel, Basel, Switzerland.
authors.forename: Nicola U
authors.initials: NU
authors.lastname: Zitzmann
mesh_terms: D003738:Dental Cements; D006801:Humans; D057873:Peri-Implantitis / Q000209:etiology*; D012307:Risk Factors; D013280:Stomatitis / Q000209:etiology*
chemical_list: D003738:Dental Cements
keywords: cement excess; implant restoration; peri-implant diseases; peri-implant mucositis; peri-implantitis; review