Document Detail

Radiopacity of compomers, flowable and conventional resin composites for posterior restorations.
MedLine Citation:
PMID:  10337294     Owner:  NLM     Status:  MEDLINE    
The objective of this study was to densitometrically determine the relative radiopacity (aluminum [Al]-equivalent values) of dentin, enamel, and 20 resin composite materials currently used for posterior restorations. Specimens 5 mm in diameter and 2 mm thick were fabricated from 20 materials (n = 7) for a total of 140 specimens. Human molars were longitudinally sectioned 2.0 mm thick to include both enamel and dentin. The optical densities of enamel, dentin, restorative materials, lead, and aluminum step wedge were obtained from radiographic images, using a transmission photodensitometer. The Al equivalent (mm) for each material was calculated from the linear regression equation of the log of normalized optical density and Al mm thickness obtained from the step wedge. A linear regression of the logarithm of normalized optical density and Al mm thickness was plotted (r2 = 0.9953), and the relative radiopacities, expressed as equivalent thickness of Al, were ranked ordinally. All materials tested, with the exception of an unfilled resin adhesive, complied with ISO Standard 4049, being at least as radiopaque as a 2.0 mm thickness of 99.6% pure Al. Four of six flowable composites had radiopacity values that fell between that of dentin and enamel, while two materials were more radiopaque than enamel. The three compomers tested had radiopacities greater than enamel. In addition, all traditional light- and chemical-cure resin composite materials tested were more radiopaque than enamel. All materials tested, with the exception of one adhesive resin, were at least as radiopaque as dentin and complied with ISO Standard 4049. Clinicians should be able to distinguish these restorative materials radiographically from recurrent decay, voids, gaps, or other defects that lead to clinical failure. Utilization of materials ranked more radiopaque than enamel would enable clinicians to distinguish the restorative material from tooth structure.
M R Bouschlicher; D S Cobb; D B Boyer
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Operative dentistry     Volume:  24     ISSN:  0361-7734     ISO Abbreviation:  Oper Dent     Publication Date:    1999 Jan-Feb
Date Detail:
Created Date:  1999-05-25     Completed Date:  1999-05-25     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7605679     Medline TA:  Oper Dent     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  20-5     Citation Subset:  D    
University of Iowa, Department of Operative Dentistry, Iowa City 52242-1001, USA.
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MeSH Terms
Absorptiometry, Photon
Composite Resins / chemistry*
Contrast Media
Glass Ionomer Cements / chemistry*
Linear Models
Radiography, Dental*
Reg. No./Substance:
0/Composite Resins; 0/Contrast Media; 0/Glass Ionomer Cements

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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