title: Caries-Preventive Effect of High-Viscosity Glass Ionomer and Resin-Based Fissure Sealants on Permanent Teeth: A Systematic Review of Clinical Trials.
abstract: BACKGROUND
  Glass-ionomers are traditionally regarded to be inferior to resin as fissure sealants in protecting teeth from dental caries, due to their comparatively lower retention rate. Unlike low-viscosity glass-ionomers, high-viscosity glass-ionomer cements (HVGIC) are placed as sealants by pressing the material into pits and fissures with a petroleum-jelly-coated index finger. Hence, HVGIC sealants are assumed to penetrate pits and fissures deeper, resulting in a higher material retention rate, which may increase its caries-preventive effect.
  
  
  METHODS
  The aim of this review was to answer the question as to whether, in patients with fully erupted permanent molar teeth, HVGIC based fissure sealants are less effective to protect against dental carious lesions in occlusal pits and fissures than resin-based fissure sealants? A systematic literature search in eight databases was conducted. Heterogeneity of accepted trials and imprecision of the established evidence were assessed. Extracted sufficiently homogenous datasets were pooled by use of a random-effects meta-analysis. Internal trial validity was evaluated. The protocol of this systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO / Nr.: CRD42015016007).
  
  
  RESULTS
  Seven clinical trials were provisionally included for further review. Of these, one was excluded. Seven trial reports reporting on six trials were accepted. From these, 11 datasets were extracted and pooled in four meta-analyses. The results suggest no statistically significant differences after up to 48 months and borderline significant differences in favour of HVGIC sealants after 60 months (RR 0.29; 95% CI: 0.09-0.95; p = 0.04 / RD -0.07; 95% CI: -0.14, -0.01). The point estimates and upper confidence levels after 24, 36, 48 and 60 months of RR 1.36; RR 0.90; RR 0.62; RR 0.29 and 2.78; 1.67; 1.21; 0.95, respectively, further suggest a chronological trend in favour of HVGIC above resin-based sealants. The internal trial validity was judged to be low and the bias risk high for all trials. Imprecision of results was considered too high for clinical guidance.
  
  
  CONCLUSIONS
  It can be concluded that: (i) Inferiority claims against HVGIC in comparison to resin-based sealants as current gold-standard are not supported by the clinical evidence; (ii) The clinical evidence suggests similar caries-preventive efficacy of HVGIC and resin-based sealants after a period of 48 months in permanent molar teeth but remains challenged by high bias risk; (iii) Evidence concerning a possible superiority of HVGIC above resin-based sealants after 60 months is poor (even if the high bias risk is disregarded) due to imprecision and requires corroboration through future research.
authors.affiliation: Systematic Review initiative for Evidence-based Minimum Intervention in Dentistry/Department of Community Dentistry, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Steffen
authors.initials: S
authors.lastname: Mickenautsch
authors.affiliation: Systematic Review initiative for Evidence-based Minimum Intervention in Dentistry/Department of Community Dentistry, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Veerasamy
authors.initials: V
authors.lastname: Yengopal
mesh_terms: D000180:Acrylic Resins / Q000627:therapeutic use*; D002648:Child; D003731:Dental Caries / Q000517:prevention & control*; D005260:Female; D005899:Glass Ionomer Cements / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D010895:Pit and Fissure Sealants / Q000627:therapeutic use*; D019279:Resin Cements / Q000627:therapeutic use*; D012822:Silicon Dioxide / Q000627:therapeutic use*; D014070:Tooth / Q000473:pathology
chemical_list: D000180:Acrylic Resins; D005899:Glass Ionomer Cements; D010895:Pit and Fissure Sealants; D019279:Resin Cements; C015897:glass ionomer; D012822:Silicon Dioxide