Role of saliva and salivary components as modulators of bleaching agent toxicity to human gingival fibroblasts in vitro

David Tipton, S. D. Braxton, M. K. Dabbous

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Mild oxygenating agents generating H2O2 are used for effective at-home tooth bleaching, but can cause gingival ulcers in some patients. There are concerns about the possible pathological effects of relatively long-term exposure of oral tissues to bleaching agents. Previous work in our laboraory showed that a bleaching agent, which generates ~3% H2O2 from carbamide peroxide, was toxic to human gingival fibroblasts in vitro, but that the toxicity was abolished by treatment with the H2O2-destroying enzyme catalase. The purpose of the present study was to determine if whole saliva, the salivary enzyme lactoperoxidase (LP) (which, like catalase, removes H2O2), or salivary mucin protected fibroblasts from bleaching agent toxicity. The cells were exposed to 0.05% agent with or without saliva, LP, mucin or catalase (as a positive control based on our previous study) and assessed for effect on viability/morphology (by microscopic observation), proliferation (by [3H]-thymidine incorporation), and the production of fibronectin (FN) and type I collagen (by ELISA). While the bleaching agent at 0.05% caused cell death, the cells appeared viable and morphologically normal when treated with the bleaching agent and LP (≥0.1 μM), saliva (>4%), or catalase (>0.3 μg/ml). There was dose-dependent protection by saliva, LP, and catalase from agent inhibition of proliferation (P ≤ 0.04) and FN production (P ≤ 0.01). Mucin had statistically insignificant or no protective effect as assessed by the above parameters. Treatment with saliva, LP, mucin, and catalase gave complete or partial protection from agent-inhibition of collagen production (P ≤ 0.04). The results suggest that the toxicity of the agent is largely due to H2O2, and that it may be reduced or abolished in vivo by enzymes present in saliva and/or the oral tissues which break down H2O2.

Original languageEnglish (US)
Pages (from-to)766-774
Number of pages9
JournalJournal of periodontology
Volume66
Issue number9
DOIs
StatePublished - Jan 1 1995

Fingerprint

Bleaching Agents
Lactoperoxidase
Saliva
Catalase
Fibroblasts
Mucins
Fibronectins
Enzymes
Tooth Bleaching
Poisons
Collagen Type I
Thymidine
Ulcer
In Vitro Techniques
Cell Death
Collagen
Enzyme-Linked Immunosorbent Assay
Therapeutics

All Science Journal Classification (ASJC) codes

  • Periodontics

Cite this

Role of saliva and salivary components as modulators of bleaching agent toxicity to human gingival fibroblasts in vitro. / Tipton, David; Braxton, S. D.; Dabbous, M. K.

In: Journal of periodontology, Vol. 66, No. 9, 01.01.1995, p. 766-774.

Research output: Contribution to journalArticle

@article{d37b67f8a2384408ab948942a1b3c80a,
title = "Role of saliva and salivary components as modulators of bleaching agent toxicity to human gingival fibroblasts in vitro",
abstract = "Mild oxygenating agents generating H2O2 are used for effective at-home tooth bleaching, but can cause gingival ulcers in some patients. There are concerns about the possible pathological effects of relatively long-term exposure of oral tissues to bleaching agents. Previous work in our laboraory showed that a bleaching agent, which generates ~3{\%} H2O2 from carbamide peroxide, was toxic to human gingival fibroblasts in vitro, but that the toxicity was abolished by treatment with the H2O2-destroying enzyme catalase. The purpose of the present study was to determine if whole saliva, the salivary enzyme lactoperoxidase (LP) (which, like catalase, removes H2O2), or salivary mucin protected fibroblasts from bleaching agent toxicity. The cells were exposed to 0.05{\%} agent with or without saliva, LP, mucin or catalase (as a positive control based on our previous study) and assessed for effect on viability/morphology (by microscopic observation), proliferation (by [3H]-thymidine incorporation), and the production of fibronectin (FN) and type I collagen (by ELISA). While the bleaching agent at 0.05{\%} caused cell death, the cells appeared viable and morphologically normal when treated with the bleaching agent and LP (≥0.1 μM), saliva (>4{\%}), or catalase (>0.3 μg/ml). There was dose-dependent protection by saliva, LP, and catalase from agent inhibition of proliferation (P ≤ 0.04) and FN production (P ≤ 0.01). Mucin had statistically insignificant or no protective effect as assessed by the above parameters. Treatment with saliva, LP, mucin, and catalase gave complete or partial protection from agent-inhibition of collagen production (P ≤ 0.04). The results suggest that the toxicity of the agent is largely due to H2O2, and that it may be reduced or abolished in vivo by enzymes present in saliva and/or the oral tissues which break down H2O2.",
author = "David Tipton and Braxton, {S. D.} and Dabbous, {M. K.}",
year = "1995",
month = "1",
day = "1",
doi = "10.1902/jop.1995.66.9.766",
language = "English (US)",
volume = "66",
pages = "766--774",
journal = "Journal of Periodontology",
issn = "0022-3492",
publisher = "American Academy of Periodontology",
number = "9",

}

TY - JOUR

T1 - Role of saliva and salivary components as modulators of bleaching agent toxicity to human gingival fibroblasts in vitro

AU - Tipton, David

AU - Braxton, S. D.

AU - Dabbous, M. K.

PY - 1995/1/1

Y1 - 1995/1/1

N2 - Mild oxygenating agents generating H2O2 are used for effective at-home tooth bleaching, but can cause gingival ulcers in some patients. There are concerns about the possible pathological effects of relatively long-term exposure of oral tissues to bleaching agents. Previous work in our laboraory showed that a bleaching agent, which generates ~3% H2O2 from carbamide peroxide, was toxic to human gingival fibroblasts in vitro, but that the toxicity was abolished by treatment with the H2O2-destroying enzyme catalase. The purpose of the present study was to determine if whole saliva, the salivary enzyme lactoperoxidase (LP) (which, like catalase, removes H2O2), or salivary mucin protected fibroblasts from bleaching agent toxicity. The cells were exposed to 0.05% agent with or without saliva, LP, mucin or catalase (as a positive control based on our previous study) and assessed for effect on viability/morphology (by microscopic observation), proliferation (by [3H]-thymidine incorporation), and the production of fibronectin (FN) and type I collagen (by ELISA). While the bleaching agent at 0.05% caused cell death, the cells appeared viable and morphologically normal when treated with the bleaching agent and LP (≥0.1 μM), saliva (>4%), or catalase (>0.3 μg/ml). There was dose-dependent protection by saliva, LP, and catalase from agent inhibition of proliferation (P ≤ 0.04) and FN production (P ≤ 0.01). Mucin had statistically insignificant or no protective effect as assessed by the above parameters. Treatment with saliva, LP, mucin, and catalase gave complete or partial protection from agent-inhibition of collagen production (P ≤ 0.04). The results suggest that the toxicity of the agent is largely due to H2O2, and that it may be reduced or abolished in vivo by enzymes present in saliva and/or the oral tissues which break down H2O2.

AB - Mild oxygenating agents generating H2O2 are used for effective at-home tooth bleaching, but can cause gingival ulcers in some patients. There are concerns about the possible pathological effects of relatively long-term exposure of oral tissues to bleaching agents. Previous work in our laboraory showed that a bleaching agent, which generates ~3% H2O2 from carbamide peroxide, was toxic to human gingival fibroblasts in vitro, but that the toxicity was abolished by treatment with the H2O2-destroying enzyme catalase. The purpose of the present study was to determine if whole saliva, the salivary enzyme lactoperoxidase (LP) (which, like catalase, removes H2O2), or salivary mucin protected fibroblasts from bleaching agent toxicity. The cells were exposed to 0.05% agent with or without saliva, LP, mucin or catalase (as a positive control based on our previous study) and assessed for effect on viability/morphology (by microscopic observation), proliferation (by [3H]-thymidine incorporation), and the production of fibronectin (FN) and type I collagen (by ELISA). While the bleaching agent at 0.05% caused cell death, the cells appeared viable and morphologically normal when treated with the bleaching agent and LP (≥0.1 μM), saliva (>4%), or catalase (>0.3 μg/ml). There was dose-dependent protection by saliva, LP, and catalase from agent inhibition of proliferation (P ≤ 0.04) and FN production (P ≤ 0.01). Mucin had statistically insignificant or no protective effect as assessed by the above parameters. Treatment with saliva, LP, mucin, and catalase gave complete or partial protection from agent-inhibition of collagen production (P ≤ 0.04). The results suggest that the toxicity of the agent is largely due to H2O2, and that it may be reduced or abolished in vivo by enzymes present in saliva and/or the oral tissues which break down H2O2.

UR - http://www.scopus.com/inward/record.url?scp=0028850489&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028850489&partnerID=8YFLogxK

U2 - 10.1902/jop.1995.66.9.766

DO - 10.1902/jop.1995.66.9.766

M3 - Article

VL - 66

SP - 766

EP - 774

JO - Journal of Periodontology

JF - Journal of Periodontology

SN - 0022-3492

IS - 9

ER -