Dental Materials
Volume 25, Issue 7 , Pages 884-891, July 2009

In vitro remineralization of enamel by polymeric amorphous calcium phosphate composite: Quantitative microradiographic study

Paffenbarger Research Center, American Dental Association Foundation, National Institute of Standards and Technology, 100 Bureau Drive Stop 8546, Gaithersburg, MD 20899-8546, USA

Received 3 November 2008; received in revised form 12 January 2009; accepted 14 January 2009.

Abstract 

Objective

This study explores the efficacy of an experimental orthodontic amorphous calcium phosphate (ACP) composite to remineralize in vitro subsurface enamel lesions microradiographically similar to those seen in early caries.

Methods

Lesions were artificially created in extracted human molars. Single tooth sections a minimum of 120μm thick were cut and individually placed in holders exposing only the carious enamel surface. The exposed surfaces were either left untreated (control) or coated with a 1mm thick layer of the experimental ACP composite (mass fraction 40% zirconia-hybridized ACP and 60% photo-activated resin), or a commercial fluoride-releasing orthodontic cement. The composite-coated sections were then photo-cured and microradiographic images were taken of all three groups of specimens before the treatment. Specimens were then cyclically immersed in demineralizing and remineralizing solutions for 1 month at 37°C to simulate the pH changes occurring in the oral environment. Microradiographs of all specimens were taken before and after treatment.

Results

Quantitative digital image analysis of matched areas from the contact microradiographs taken before and after treatment indicated higher mineral recovery with ACP composites compared to the commercial orthodontic F-releasing cement (14.4% vs. 4.3%, respectively), while the control specimens showed an average of 55.4% further demineralization.

Significance

Experimental ACP composite efficiently established mineral ion transfer throughout the body of the lesions and restored the mineral lost due to acid attack. It can be considered a useful adjuvant for the control of caries in orthodontic applications.

Keywords: Amorphous calcium phosphate, Caries, Enamel, Polymeric composite, Remineralization

To access this article, please choose from the options below

Login to an existing account or Register a new account.

  • Purchase this article for 31.50 USD (You must login/register to purchase this article)

    Online access for 24 hours. The PDF version can be downloaded as your permanent record.

  • Subscribe to this title

    Get unlimited online access to this article and all other articles in this title 24/7 for one year.

  • Claim access now

    For current subscribers with Society Membership or Account Number.

  • Visit SciVerse ScienceDirect to see if you have access via your institution.
 

 Certain commercial materials and equipment are identified in this work for adequate definition of the experimental procedures. In no instance does such identification imply recommendation or endorsement by the American Dental Association Foundation or the National Institute of Standards and Technology, or that the material and the equipment identified is necessarily the best available for the purpose.

PII: S0109-5641(09)00100-6

doi:10.1016/j.dental.2009.01.094

Dental Materials
Volume 25, Issue 7 , Pages 884-891, July 2009