Intracoronal stress transfer through enamel following RBC photopolymerisation: A synchrotron X-ray study

Research output: Contribution to journalArticlepeer-review

Standard

Intracoronal stress transfer through enamel following RBC photopolymerisation : A synchrotron X-ray study. / Al-Jawad, Maisoon; Addison, Owen; Sirovica, Slobodan; Siddiqui, Samera; Martin, Richard A; Wood, David J; Watts, David C.

In: Dental Materials, 14.08.2018.

Research output: Contribution to journalArticlepeer-review

Harvard

APA

Vancouver

Author

Al-Jawad, Maisoon ; Addison, Owen ; Sirovica, Slobodan ; Siddiqui, Samera ; Martin, Richard A ; Wood, David J ; Watts, David C. / Intracoronal stress transfer through enamel following RBC photopolymerisation : A synchrotron X-ray study. In: Dental Materials. 2018.

Bibtex

@article{0380ba12da4c4de7baade66253f08651,
title = "Intracoronal stress transfer through enamel following RBC photopolymerisation: A synchrotron X-ray study",
abstract = "OBJECTIVES: To measure the spatial distribution of crystallographic strain in tooth enamel induced by the photo-polymerisation of a dimethacrylate resin based composite cavity restoration.METHODS: Six sound first premolar teeth, allocated into two groups (n=3), were prepared with mesio-occlusal distal cavities. The enamel was machined at the point of maximum convexity on the outer tooth to create a vertical fin of thickness 100μm and 0.5mm depth to allow for synchrotron X-ray diffraction measurements. 2D diffraction patterns were used to determine crystallite orientation and quantify changes in the hydroxyapatite crystal lattice parameters, before and after photo-polymerisation of a composite material placed in the cavity, to calculate strain in the respective axis. The composite was photo-polymerised with either relatively high (1200mWcm-2, group 1) or low (480mWcm-2, group 2) irradiances using LED or quartz halogen light sources, respectively. A paired t-test was used to determine significant differences in strain between irradiance protocols at ɑ=0.001.RESULTS: Photo-polymerisation of the composite in the adjacent cavity induced significant changes in both the crystallographic c and a axes of the enamel measurement area. However the magnitude of strain was low with ∼0.1% difference before and after composite photo-polymerisation. Strain in enamel was not uniformly distributed and varied spatially as a function of crystallite orientation. Increased alignment of crystallites perpendicular to the cavity wall was associated with higher c axis strain. Additionally, strain was significantly greater in the c (p<0.001) and a axis (p<0.001) when using a high irradiance photo-polymerisation protocol.SIGNIFICANCE: Although cuspal deflection is routinely measured to indirectly assess the 'global' effect of composite shrinkage on the tooth-restoration complex, here we show that absolute strains generated in enamel are low, indicating strain relief mechanisms may be operative. The use of low irradiance protocols for photo-polymerisation resulted in reduced strain.",
author = "Maisoon Al-Jawad and Owen Addison and Slobodan Sirovica and Samera Siddiqui and Martin, {Richard A} and Wood, {David J} and Watts, {David C}",
note = "Copyright {\textcopyright} 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.",
year = "2018",
month = aug,
day = "14",
doi = "10.1016/j.dental.2018.07.005",
language = "English",
journal = "Dental Materials",
issn = "0109-5641",
publisher = "Elsevier",

}

RIS

TY - JOUR

T1 - Intracoronal stress transfer through enamel following RBC photopolymerisation

T2 - A synchrotron X-ray study

AU - Al-Jawad, Maisoon

AU - Addison, Owen

AU - Sirovica, Slobodan

AU - Siddiqui, Samera

AU - Martin, Richard A

AU - Wood, David J

AU - Watts, David C

N1 - Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

PY - 2018/8/14

Y1 - 2018/8/14

N2 - OBJECTIVES: To measure the spatial distribution of crystallographic strain in tooth enamel induced by the photo-polymerisation of a dimethacrylate resin based composite cavity restoration.METHODS: Six sound first premolar teeth, allocated into two groups (n=3), were prepared with mesio-occlusal distal cavities. The enamel was machined at the point of maximum convexity on the outer tooth to create a vertical fin of thickness 100μm and 0.5mm depth to allow for synchrotron X-ray diffraction measurements. 2D diffraction patterns were used to determine crystallite orientation and quantify changes in the hydroxyapatite crystal lattice parameters, before and after photo-polymerisation of a composite material placed in the cavity, to calculate strain in the respective axis. The composite was photo-polymerised with either relatively high (1200mWcm-2, group 1) or low (480mWcm-2, group 2) irradiances using LED or quartz halogen light sources, respectively. A paired t-test was used to determine significant differences in strain between irradiance protocols at ɑ=0.001.RESULTS: Photo-polymerisation of the composite in the adjacent cavity induced significant changes in both the crystallographic c and a axes of the enamel measurement area. However the magnitude of strain was low with ∼0.1% difference before and after composite photo-polymerisation. Strain in enamel was not uniformly distributed and varied spatially as a function of crystallite orientation. Increased alignment of crystallites perpendicular to the cavity wall was associated with higher c axis strain. Additionally, strain was significantly greater in the c (p<0.001) and a axis (p<0.001) when using a high irradiance photo-polymerisation protocol.SIGNIFICANCE: Although cuspal deflection is routinely measured to indirectly assess the 'global' effect of composite shrinkage on the tooth-restoration complex, here we show that absolute strains generated in enamel are low, indicating strain relief mechanisms may be operative. The use of low irradiance protocols for photo-polymerisation resulted in reduced strain.

AB - OBJECTIVES: To measure the spatial distribution of crystallographic strain in tooth enamel induced by the photo-polymerisation of a dimethacrylate resin based composite cavity restoration.METHODS: Six sound first premolar teeth, allocated into two groups (n=3), were prepared with mesio-occlusal distal cavities. The enamel was machined at the point of maximum convexity on the outer tooth to create a vertical fin of thickness 100μm and 0.5mm depth to allow for synchrotron X-ray diffraction measurements. 2D diffraction patterns were used to determine crystallite orientation and quantify changes in the hydroxyapatite crystal lattice parameters, before and after photo-polymerisation of a composite material placed in the cavity, to calculate strain in the respective axis. The composite was photo-polymerised with either relatively high (1200mWcm-2, group 1) or low (480mWcm-2, group 2) irradiances using LED or quartz halogen light sources, respectively. A paired t-test was used to determine significant differences in strain between irradiance protocols at ɑ=0.001.RESULTS: Photo-polymerisation of the composite in the adjacent cavity induced significant changes in both the crystallographic c and a axes of the enamel measurement area. However the magnitude of strain was low with ∼0.1% difference before and after composite photo-polymerisation. Strain in enamel was not uniformly distributed and varied spatially as a function of crystallite orientation. Increased alignment of crystallites perpendicular to the cavity wall was associated with higher c axis strain. Additionally, strain was significantly greater in the c (p<0.001) and a axis (p<0.001) when using a high irradiance photo-polymerisation protocol.SIGNIFICANCE: Although cuspal deflection is routinely measured to indirectly assess the 'global' effect of composite shrinkage on the tooth-restoration complex, here we show that absolute strains generated in enamel are low, indicating strain relief mechanisms may be operative. The use of low irradiance protocols for photo-polymerisation resulted in reduced strain.

U2 - 10.1016/j.dental.2018.07.005

DO - 10.1016/j.dental.2018.07.005

M3 - Article

C2 - 30119841

JO - Dental Materials

JF - Dental Materials

SN - 0109-5641

ER -