Dental Composites with Calcium / Strontium Phosphates and Polylysine.

PURPOSE:This study developed light cured dental composites with added monocalcium phosphate monohydrate (MCPM), tristrontium phosphate (TSrP) and antimicrobial polylysine (PLS). The aim was to produce composites that have enhanced water sorption induced expansion, can promote apatite precipitation a...

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Main Authors: Piyaphong Panpisut, Saad Liaqat, Eleni Zacharaki, Wendy Xia, Haralampos Petridis, Anne Margaret Young
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2016-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC5058497?pdf=render
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author Piyaphong Panpisut
Saad Liaqat
Eleni Zacharaki
Wendy Xia
Haralampos Petridis
Anne Margaret Young
author_facet Piyaphong Panpisut
Saad Liaqat
Eleni Zacharaki
Wendy Xia
Haralampos Petridis
Anne Margaret Young
author_sort Piyaphong Panpisut
collection DOAJ
description PURPOSE:This study developed light cured dental composites with added monocalcium phosphate monohydrate (MCPM), tristrontium phosphate (TSrP) and antimicrobial polylysine (PLS). The aim was to produce composites that have enhanced water sorption induced expansion, can promote apatite precipitation and release polylysine. MATERIALS AND METHODS:Experimental composite formulations consisted of light activated dimethacrylate monomers combined with 80 wt% powder. The powder phase contained a dental glass with and without PLS (2.5 wt%) and/or reactive phosphate fillers (15 wt% TSrP and 10 wt% MCPM). The commercial composite, Z250, was used as a control. Monomer conversion and calculated polymerization shrinkage were assessed using FTIR. Subsequent mass or volume changes in water versus simulated body fluid (SBF) were quantified using gravimetric studies. These were used, along with Raman and SEM, to assess apatite precipitation on the composite surface. PLS release was determined using UV spectroscopy. Furthermore, biaxial flexural strengths after 24 hours of SBF immersion were obtained. RESULTS:Monomer conversion of the composites decreased upon the addition of phosphate fillers (from 76 to 64%) but was always higher than that of Z250 (54%). Phosphate addition increased water sorption induced expansion from 2 to 4% helping to balance the calculated polymerization shrinkage of ~ 3.4%. Phosphate addition promoted apatite precipitation from SBF. Polylysine increased the apatite layer thickness from ~ 10 to 20 μm after 4 weeks. The novel composites showed a burst release of PLS (3.7%) followed by diffusion-controlled release irrespective of phosphate addition. PLS and phosphates decreased strength from 154 MPa on average by 17% and 18%, respectively. All formulations, however, had greater strength than the ISO 4049 requirement of > 80 MPa. CONCLUSION:The addition of MCPM with TSrP promoted hygroscopic expansion, and apatite formation. These properties are expected to help compensate polymerization shrinkage and help remineralize demineralized dentin. Polylysine can be released from the composites at early time. This may kill residual bacteria.
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spelling doaj.art-7dacaece20504ce5ab4a346ba93ebbf22022-12-21T19:39:10ZengPublic Library of Science (PLoS)PLoS ONE1932-62032016-01-011110e016465310.1371/journal.pone.0164653Dental Composites with Calcium / Strontium Phosphates and Polylysine.Piyaphong PanpisutSaad LiaqatEleni ZacharakiWendy XiaHaralampos PetridisAnne Margaret YoungPURPOSE:This study developed light cured dental composites with added monocalcium phosphate monohydrate (MCPM), tristrontium phosphate (TSrP) and antimicrobial polylysine (PLS). The aim was to produce composites that have enhanced water sorption induced expansion, can promote apatite precipitation and release polylysine. MATERIALS AND METHODS:Experimental composite formulations consisted of light activated dimethacrylate monomers combined with 80 wt% powder. The powder phase contained a dental glass with and without PLS (2.5 wt%) and/or reactive phosphate fillers (15 wt% TSrP and 10 wt% MCPM). The commercial composite, Z250, was used as a control. Monomer conversion and calculated polymerization shrinkage were assessed using FTIR. Subsequent mass or volume changes in water versus simulated body fluid (SBF) were quantified using gravimetric studies. These were used, along with Raman and SEM, to assess apatite precipitation on the composite surface. PLS release was determined using UV spectroscopy. Furthermore, biaxial flexural strengths after 24 hours of SBF immersion were obtained. RESULTS:Monomer conversion of the composites decreased upon the addition of phosphate fillers (from 76 to 64%) but was always higher than that of Z250 (54%). Phosphate addition increased water sorption induced expansion from 2 to 4% helping to balance the calculated polymerization shrinkage of ~ 3.4%. Phosphate addition promoted apatite precipitation from SBF. Polylysine increased the apatite layer thickness from ~ 10 to 20 μm after 4 weeks. The novel composites showed a burst release of PLS (3.7%) followed by diffusion-controlled release irrespective of phosphate addition. PLS and phosphates decreased strength from 154 MPa on average by 17% and 18%, respectively. All formulations, however, had greater strength than the ISO 4049 requirement of > 80 MPa. CONCLUSION:The addition of MCPM with TSrP promoted hygroscopic expansion, and apatite formation. These properties are expected to help compensate polymerization shrinkage and help remineralize demineralized dentin. Polylysine can be released from the composites at early time. This may kill residual bacteria.http://europepmc.org/articles/PMC5058497?pdf=render
spellingShingle Piyaphong Panpisut
Saad Liaqat
Eleni Zacharaki
Wendy Xia
Haralampos Petridis
Anne Margaret Young
Dental Composites with Calcium / Strontium Phosphates and Polylysine.
PLoS ONE
title Dental Composites with Calcium / Strontium Phosphates and Polylysine.
title_full Dental Composites with Calcium / Strontium Phosphates and Polylysine.
title_fullStr Dental Composites with Calcium / Strontium Phosphates and Polylysine.
title_full_unstemmed Dental Composites with Calcium / Strontium Phosphates and Polylysine.
title_short Dental Composites with Calcium / Strontium Phosphates and Polylysine.
title_sort dental composites with calcium strontium phosphates and polylysine
url http://europepmc.org/articles/PMC5058497?pdf=render
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AT elenizacharaki dentalcompositeswithcalciumstrontiumphosphatesandpolylysine
AT wendyxia dentalcompositeswithcalciumstrontiumphosphatesandpolylysine
AT haralampospetridis dentalcompositeswithcalciumstrontiumphosphatesandpolylysine
AT annemargaretyoung dentalcompositeswithcalciumstrontiumphosphatesandpolylysine