Mapping camphorquinone consumption, conversion and mechanical properties in methacrylates with systematically varied CQ/amine compositions

T. Guimarães, L. F. Schneider, R. R. Braga, Carmem Pfeifer

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Objectives. To evaluate conversion, bulk mechanical properties and camphorquinone (CQ)consumption in methacrylate resins, comprising a range of overall initiator concentrationsand CQ/amine ratios.

Methods. BisGMA (Bisphenol-A glycidyl dimethacrylate), TEGDMA (triethyleneglycoldimethacrylate) and UDMA (urethane dimethacrylate) were mixed at a 1:1:1 molar ratio.CQ was used as the visible light photosensitizer, in combination with EDMAB (Ethyl p-dimethylamino benzoate), at 3:1, 2:1, 1:1, 1:2 and 1:3 weight ratios, at 0.5, 1.0, 1.5, 2.0 and3.0 wt% overall initiator concentration. Butylhydroxytoluene was added at 0.05 wt% as aninhibitor. Unfilled resins were photoactivated with a dental light source (VIP Jr, Bisco) for60 s at 600 mW/cm2. Flexural strength/modulus were assessed in 2 × 1 × 10 mm bars, testedin three-point bending. Degree of conversion was assessed at the bottom of the same speci-mens using FT-RAMAN. CQ consumption was measured using a UV-vis spectrometer. Datawere analyzed with two-way ANOVA/Tukey test (α = 5%).

Results. Lower conversion and inferior mechanical properties were observed with loweroverall initiator concentrations and higher amine/CQ ratios. The lowest overall initiator con-centration (0.5%) presented the statistically lowest conversion/properties results, except forthe 1:3 amine/CQ ratio. For overall concentrations equal or greater to 1.5%, the amine/CQratio did not influence conversion or mechanical properties. CQ consumption was less effi-cient for the highest overall initiator concentrations and lower amine/CQ ratios.

Clinical relevance. Above 1.5 wt% overall initiator concentration, the conversion and gen-eral mechanical properties were independent of the initiator concentration. Therefore,there seems to be no benefit to increasing the initiator concentration above that level. At higher camphorquinone concentrations, light transmission and photosensitizer consumption becomes impaired, which could lead to decreased depth of cure and yellowing of the restoration.

Original languageEnglish (US)
Pages (from-to)1274-1279
Number of pages6
JournalDental Materials
Volume30
Issue number11
DOIs
StatePublished - Nov 1 2014

Fingerprint

Methacrylates
Amines
Mechanical properties
Chemical analysis
Photosensitizers
Resins
Ultraviolet spectrometers
Photosensitizing Agents
Light
Light transmission
Analysis of variance (ANOVA)
Bending strength
Restoration
Light sources
camphorquinone
Butylated Hydroxytoluene
Benzoates
Analysis of Variance
Tooth
Weights and Measures

Keywords

  • Amine
  • Camphorquinone
  • Degree of conversion
  • Methacrylates
  • Photopolymerization

ASJC Scopus subject areas

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

Cite this

Mapping camphorquinone consumption, conversion and mechanical properties in methacrylates with systematically varied CQ/amine compositions. / Guimarães, T.; Schneider, L. F.; Braga, R. R.; Pfeifer, Carmem.

In: Dental Materials, Vol. 30, No. 11, 01.11.2014, p. 1274-1279.

Research output: Contribution to journalArticle

@article{299205693555419a8f7f3352190176a7,
title = "Mapping camphorquinone consumption, conversion and mechanical properties in methacrylates with systematically varied CQ/amine compositions",
abstract = "Objectives. To evaluate conversion, bulk mechanical properties and camphorquinone (CQ)consumption in methacrylate resins, comprising a range of overall initiator concentrationsand CQ/amine ratios.Methods. BisGMA (Bisphenol-A glycidyl dimethacrylate), TEGDMA (triethyleneglycoldimethacrylate) and UDMA (urethane dimethacrylate) were mixed at a 1:1:1 molar ratio.CQ was used as the visible light photosensitizer, in combination with EDMAB (Ethyl p-dimethylamino benzoate), at 3:1, 2:1, 1:1, 1:2 and 1:3 weight ratios, at 0.5, 1.0, 1.5, 2.0 and3.0 wt{\%} overall initiator concentration. Butylhydroxytoluene was added at 0.05 wt{\%} as aninhibitor. Unfilled resins were photoactivated with a dental light source (VIP Jr, Bisco) for60 s at 600 mW/cm2. Flexural strength/modulus were assessed in 2 × 1 × 10 mm bars, testedin three-point bending. Degree of conversion was assessed at the bottom of the same speci-mens using FT-RAMAN. CQ consumption was measured using a UV-vis spectrometer. Datawere analyzed with two-way ANOVA/Tukey test (α = 5{\%}).Results. Lower conversion and inferior mechanical properties were observed with loweroverall initiator concentrations and higher amine/CQ ratios. The lowest overall initiator con-centration (0.5{\%}) presented the statistically lowest conversion/properties results, except forthe 1:3 amine/CQ ratio. For overall concentrations equal or greater to 1.5{\%}, the amine/CQratio did not influence conversion or mechanical properties. CQ consumption was less effi-cient for the highest overall initiator concentrations and lower amine/CQ ratios.Clinical relevance. Above 1.5 wt{\%} overall initiator concentration, the conversion and gen-eral mechanical properties were independent of the initiator concentration. Therefore,there seems to be no benefit to increasing the initiator concentration above that level. At higher camphorquinone concentrations, light transmission and photosensitizer consumption becomes impaired, which could lead to decreased depth of cure and yellowing of the restoration.",
keywords = "Amine, Camphorquinone, Degree of conversion, Methacrylates, Photopolymerization",
author = "T. Guimar{\~a}es and Schneider, {L. F.} and Braga, {R. R.} and Carmem Pfeifer",
year = "2014",
month = "11",
day = "1",
doi = "10.1016/j.dental.2014.08.379",
language = "English (US)",
volume = "30",
pages = "1274--1279",
journal = "Dental Materials",
issn = "0109-5641",
publisher = "Elsevier Science",
number = "11",

}

TY - JOUR

T1 - Mapping camphorquinone consumption, conversion and mechanical properties in methacrylates with systematically varied CQ/amine compositions

AU - Guimarães, T.

AU - Schneider, L. F.

AU - Braga, R. R.

AU - Pfeifer, Carmem

PY - 2014/11/1

Y1 - 2014/11/1

N2 - Objectives. To evaluate conversion, bulk mechanical properties and camphorquinone (CQ)consumption in methacrylate resins, comprising a range of overall initiator concentrationsand CQ/amine ratios.Methods. BisGMA (Bisphenol-A glycidyl dimethacrylate), TEGDMA (triethyleneglycoldimethacrylate) and UDMA (urethane dimethacrylate) were mixed at a 1:1:1 molar ratio.CQ was used as the visible light photosensitizer, in combination with EDMAB (Ethyl p-dimethylamino benzoate), at 3:1, 2:1, 1:1, 1:2 and 1:3 weight ratios, at 0.5, 1.0, 1.5, 2.0 and3.0 wt% overall initiator concentration. Butylhydroxytoluene was added at 0.05 wt% as aninhibitor. Unfilled resins were photoactivated with a dental light source (VIP Jr, Bisco) for60 s at 600 mW/cm2. Flexural strength/modulus were assessed in 2 × 1 × 10 mm bars, testedin three-point bending. Degree of conversion was assessed at the bottom of the same speci-mens using FT-RAMAN. CQ consumption was measured using a UV-vis spectrometer. Datawere analyzed with two-way ANOVA/Tukey test (α = 5%).Results. Lower conversion and inferior mechanical properties were observed with loweroverall initiator concentrations and higher amine/CQ ratios. The lowest overall initiator con-centration (0.5%) presented the statistically lowest conversion/properties results, except forthe 1:3 amine/CQ ratio. For overall concentrations equal or greater to 1.5%, the amine/CQratio did not influence conversion or mechanical properties. CQ consumption was less effi-cient for the highest overall initiator concentrations and lower amine/CQ ratios.Clinical relevance. Above 1.5 wt% overall initiator concentration, the conversion and gen-eral mechanical properties were independent of the initiator concentration. Therefore,there seems to be no benefit to increasing the initiator concentration above that level. At higher camphorquinone concentrations, light transmission and photosensitizer consumption becomes impaired, which could lead to decreased depth of cure and yellowing of the restoration.

AB - Objectives. To evaluate conversion, bulk mechanical properties and camphorquinone (CQ)consumption in methacrylate resins, comprising a range of overall initiator concentrationsand CQ/amine ratios.Methods. BisGMA (Bisphenol-A glycidyl dimethacrylate), TEGDMA (triethyleneglycoldimethacrylate) and UDMA (urethane dimethacrylate) were mixed at a 1:1:1 molar ratio.CQ was used as the visible light photosensitizer, in combination with EDMAB (Ethyl p-dimethylamino benzoate), at 3:1, 2:1, 1:1, 1:2 and 1:3 weight ratios, at 0.5, 1.0, 1.5, 2.0 and3.0 wt% overall initiator concentration. Butylhydroxytoluene was added at 0.05 wt% as aninhibitor. Unfilled resins were photoactivated with a dental light source (VIP Jr, Bisco) for60 s at 600 mW/cm2. Flexural strength/modulus were assessed in 2 × 1 × 10 mm bars, testedin three-point bending. Degree of conversion was assessed at the bottom of the same speci-mens using FT-RAMAN. CQ consumption was measured using a UV-vis spectrometer. Datawere analyzed with two-way ANOVA/Tukey test (α = 5%).Results. Lower conversion and inferior mechanical properties were observed with loweroverall initiator concentrations and higher amine/CQ ratios. The lowest overall initiator con-centration (0.5%) presented the statistically lowest conversion/properties results, except forthe 1:3 amine/CQ ratio. For overall concentrations equal or greater to 1.5%, the amine/CQratio did not influence conversion or mechanical properties. CQ consumption was less effi-cient for the highest overall initiator concentrations and lower amine/CQ ratios.Clinical relevance. Above 1.5 wt% overall initiator concentration, the conversion and gen-eral mechanical properties were independent of the initiator concentration. Therefore,there seems to be no benefit to increasing the initiator concentration above that level. At higher camphorquinone concentrations, light transmission and photosensitizer consumption becomes impaired, which could lead to decreased depth of cure and yellowing of the restoration.

KW - Amine

KW - Camphorquinone

KW - Degree of conversion

KW - Methacrylates

KW - Photopolymerization

UR - http://www.scopus.com/inward/record.url?scp=84908128883&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84908128883&partnerID=8YFLogxK

U2 - 10.1016/j.dental.2014.08.379

DO - 10.1016/j.dental.2014.08.379

M3 - Article

VL - 30

SP - 1274

EP - 1279

JO - Dental Materials

JF - Dental Materials

SN - 0109-5641

IS - 11

ER -