In vitro cytotoxic response to lithium disilicate dental ceramics

Martha G Brackett, Petra E. Lockwood, Regina L W Messer, Jill B. Lewis, Serge Bouillaguet, John C. Wataha

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Objectives: The use of lithium disilicate dental ceramics is increasing in dentistry and previous reports have suggested that they may have greater biological risks than previously thought. We tested a hypothesis that composition and processing influence the biological properties of these ceramics. Methods: The cytotoxicity of two machined and three pressed lithium disilicate materials (n = 6) were tested in vitro using mouse fibroblasts in direct contact with the materials for 72 h. Cellular response was estimated by mitochondrial succinate dehydrogenase activity (MTT method). Mitochondrial activity was expressed as a percentage of Teflon® controls, then compared to Teflon® using 2-sided t-tests (α = 0.05). Polished materials were aged in artificial saliva and tested for cytotoxicity periodically over 6 weeks, then were repolished (320 grit SiC paper), aged and tested again for 4 weeks. Results: All materials significantly (50-70%) suppressed cellular mitochondrial activity in the initial week, but suppression decreased by 25-30% over the next 2 weeks. In weeks 4 and 6 some materials exhibited a cytotoxic 'relapse' of 10-20%. The cytotoxic response was no different for machined or pressed materials, but the presence of ZnO had at least an association with longer-term cytotoxicity and relapse. Repolishing to 320 grit did not increase cytotoxicity significantly. Significance: Our results suggest that lithium disilicates are not biologically inert, and that many have a similar cytotoxicity dynamic regardless of small differences in composition or processing.

Original languageEnglish (US)
Pages (from-to)450-456
Number of pages7
JournalDental Materials
Volume24
Issue number4
DOIs
StatePublished - Apr 1 2008

Fingerprint

Ceramics
Cytotoxicity
Tooth
Lithium
Polytetrafluoroethylene
Artificial Saliva
Recurrence
Succinate Dehydrogenase
Dentistry
Polytetrafluoroethylenes
Fibroblasts
Processing
Chemical analysis
lithia disilicate
In Vitro Techniques
Association reactions

Keywords

  • Biocompatibility
  • CAD-CAM
  • Cytotoxicity
  • Mitochondrial activity
  • Porcelain

ASJC Scopus subject areas

  • Materials Science(all)
  • Dentistry(all)
  • Mechanics of Materials

Cite this

In vitro cytotoxic response to lithium disilicate dental ceramics. / Brackett, Martha G; Lockwood, Petra E.; Messer, Regina L W; Lewis, Jill B.; Bouillaguet, Serge; Wataha, John C.

In: Dental Materials, Vol. 24, No. 4, 01.04.2008, p. 450-456.

Research output: Contribution to journalArticle

Brackett, Martha G ; Lockwood, Petra E. ; Messer, Regina L W ; Lewis, Jill B. ; Bouillaguet, Serge ; Wataha, John C. / In vitro cytotoxic response to lithium disilicate dental ceramics. In: Dental Materials. 2008 ; Vol. 24, No. 4. pp. 450-456.
@article{3d175634516d4770a513cc2ba2aa384b,
title = "In vitro cytotoxic response to lithium disilicate dental ceramics",
abstract = "Objectives: The use of lithium disilicate dental ceramics is increasing in dentistry and previous reports have suggested that they may have greater biological risks than previously thought. We tested a hypothesis that composition and processing influence the biological properties of these ceramics. Methods: The cytotoxicity of two machined and three pressed lithium disilicate materials (n = 6) were tested in vitro using mouse fibroblasts in direct contact with the materials for 72 h. Cellular response was estimated by mitochondrial succinate dehydrogenase activity (MTT method). Mitochondrial activity was expressed as a percentage of Teflon{\circledR} controls, then compared to Teflon{\circledR} using 2-sided t-tests (α = 0.05). Polished materials were aged in artificial saliva and tested for cytotoxicity periodically over 6 weeks, then were repolished (320 grit SiC paper), aged and tested again for 4 weeks. Results: All materials significantly (50-70{\%}) suppressed cellular mitochondrial activity in the initial week, but suppression decreased by 25-30{\%} over the next 2 weeks. In weeks 4 and 6 some materials exhibited a cytotoxic 'relapse' of 10-20{\%}. The cytotoxic response was no different for machined or pressed materials, but the presence of ZnO had at least an association with longer-term cytotoxicity and relapse. Repolishing to 320 grit did not increase cytotoxicity significantly. Significance: Our results suggest that lithium disilicates are not biologically inert, and that many have a similar cytotoxicity dynamic regardless of small differences in composition or processing.",
keywords = "Biocompatibility, CAD-CAM, Cytotoxicity, Mitochondrial activity, Porcelain",
author = "Brackett, {Martha G} and Lockwood, {Petra E.} and Messer, {Regina L W} and Lewis, {Jill B.} and Serge Bouillaguet and Wataha, {John C.}",
year = "2008",
month = "4",
day = "1",
doi = "10.1016/j.dental.2007.06.013",
language = "English (US)",
volume = "24",
pages = "450--456",
journal = "Dental Materials",
issn = "0109-5641",
publisher = "Elsevier Science",
number = "4",

}

TY - JOUR

T1 - In vitro cytotoxic response to lithium disilicate dental ceramics

AU - Brackett, Martha G

AU - Lockwood, Petra E.

AU - Messer, Regina L W

AU - Lewis, Jill B.

AU - Bouillaguet, Serge

AU - Wataha, John C.

PY - 2008/4/1

Y1 - 2008/4/1

N2 - Objectives: The use of lithium disilicate dental ceramics is increasing in dentistry and previous reports have suggested that they may have greater biological risks than previously thought. We tested a hypothesis that composition and processing influence the biological properties of these ceramics. Methods: The cytotoxicity of two machined and three pressed lithium disilicate materials (n = 6) were tested in vitro using mouse fibroblasts in direct contact with the materials for 72 h. Cellular response was estimated by mitochondrial succinate dehydrogenase activity (MTT method). Mitochondrial activity was expressed as a percentage of Teflon® controls, then compared to Teflon® using 2-sided t-tests (α = 0.05). Polished materials were aged in artificial saliva and tested for cytotoxicity periodically over 6 weeks, then were repolished (320 grit SiC paper), aged and tested again for 4 weeks. Results: All materials significantly (50-70%) suppressed cellular mitochondrial activity in the initial week, but suppression decreased by 25-30% over the next 2 weeks. In weeks 4 and 6 some materials exhibited a cytotoxic 'relapse' of 10-20%. The cytotoxic response was no different for machined or pressed materials, but the presence of ZnO had at least an association with longer-term cytotoxicity and relapse. Repolishing to 320 grit did not increase cytotoxicity significantly. Significance: Our results suggest that lithium disilicates are not biologically inert, and that many have a similar cytotoxicity dynamic regardless of small differences in composition or processing.

AB - Objectives: The use of lithium disilicate dental ceramics is increasing in dentistry and previous reports have suggested that they may have greater biological risks than previously thought. We tested a hypothesis that composition and processing influence the biological properties of these ceramics. Methods: The cytotoxicity of two machined and three pressed lithium disilicate materials (n = 6) were tested in vitro using mouse fibroblasts in direct contact with the materials for 72 h. Cellular response was estimated by mitochondrial succinate dehydrogenase activity (MTT method). Mitochondrial activity was expressed as a percentage of Teflon® controls, then compared to Teflon® using 2-sided t-tests (α = 0.05). Polished materials were aged in artificial saliva and tested for cytotoxicity periodically over 6 weeks, then were repolished (320 grit SiC paper), aged and tested again for 4 weeks. Results: All materials significantly (50-70%) suppressed cellular mitochondrial activity in the initial week, but suppression decreased by 25-30% over the next 2 weeks. In weeks 4 and 6 some materials exhibited a cytotoxic 'relapse' of 10-20%. The cytotoxic response was no different for machined or pressed materials, but the presence of ZnO had at least an association with longer-term cytotoxicity and relapse. Repolishing to 320 grit did not increase cytotoxicity significantly. Significance: Our results suggest that lithium disilicates are not biologically inert, and that many have a similar cytotoxicity dynamic regardless of small differences in composition or processing.

KW - Biocompatibility

KW - CAD-CAM

KW - Cytotoxicity

KW - Mitochondrial activity

KW - Porcelain

UR - http://www.scopus.com/inward/record.url?scp=38949148937&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=38949148937&partnerID=8YFLogxK

U2 - 10.1016/j.dental.2007.06.013

DO - 10.1016/j.dental.2007.06.013

M3 - Article

C2 - 17675143

AN - SCOPUS:38949148937

VL - 24

SP - 450

EP - 456

JO - Dental Materials

JF - Dental Materials

SN - 0109-5641

IS - 4

ER -