TY - JOUR
T1 - Spatio-temporal temperature fields generated coronally with bulk-fill resin composites: a thermography study
AU - Yang, Jiawei
AU - Algamaiah, Hamad
AU - Watts, D.C.
PY - 2021/8/1
Y1 - 2021/8/1
N2 - Objectives: This study aimed to investigate the effects of (i) a high-irradiance (3s)
light-curing protocol versus (ii) two standard-irradiance (10s) protocols on 2D
temperature maps during intra-dental photo-irradiation within a molar cavity restored
with either Ultra-Rapid Photo-Polymerized Bulk Fill (URPBF) composites or a preheated
thermo-viscous bulk-fill composite, compared to a standard bulk-fill resinbased-
composite (RBC). The specific objectives included visual assessment of the
temperature maps and quantitative assessment of several temperature/time plots at
four different locations.
Methods. A caries-free lower first molar cavity served as a natural tooth mold. Resin
composites were placed without intermediary adhesive. Two URPBF composites
(PFill; PFlow) and one pre-heated thermo-viscous bulk-fill composite (Viscalor: VC)
were compared to a contemporary bulk-fill composite (One Bulk Fill: OBF). Two
LED-LCU devices were used: Bluephase PowerCure (PC) and Elipar S10 (S10), with
three light-irradiation protocols (PC-3s, PC-10s and S10-10s). 2D temperature maps
over the entire coronal area were recorded for 120 s during and after irradiation using
a thermal imaging camera. Changes at four different levels were selected from the
data sets: (0, 2 and 4 mm from the cavity top and at 1 mm below the dentin cavity
floor). The maximum temperature attained (Tmax), the mean temperature rise (ΔT), the
time (s) to reach maximum temperature and the integrated areas (°C·s) under the
temperature/time (T/t) plots were identified. Data were analysed via three-way
ANOVA, One-way ANOVA, independent t-tests and Tukey post-hoc tests (p<0.05).
Results. All RBCs showed qualitatively similar temperature-time profiles. PFlow
reached Tmax in the shortest time. PC-3s (3000 mW/cm2) generated comparable ΔT to
S10-10s, except with PFill, where ΔT was greater. Despite the same irradiance (1200
mW/cm2), Elipar S10 led to higher Tmax and ΔT compared to PC-10s. The highest
Tmax and ΔT were observed at the 2 mm level, and the lowest were at 1 mm depth into
the underlying dentin.
Significance. Coronal 2D temperature maps showed rises largely confined within the
bulk-fill RBC materials, with maxima at 2 mm rather than 4 mm depth indicating
some extent of thermal insulation for the underlying dentin and pulp. RBCs
polymerized via different irradiation protocols showed similar temperature changes.
With the PC-3s protocol - also with pre-heated VC - minimal temperature rises at 1
mm within dentin suggest their clinical safety when sufficient remaining dentin
thickness is present.
AB - Objectives: This study aimed to investigate the effects of (i) a high-irradiance (3s)
light-curing protocol versus (ii) two standard-irradiance (10s) protocols on 2D
temperature maps during intra-dental photo-irradiation within a molar cavity restored
with either Ultra-Rapid Photo-Polymerized Bulk Fill (URPBF) composites or a preheated
thermo-viscous bulk-fill composite, compared to a standard bulk-fill resinbased-
composite (RBC). The specific objectives included visual assessment of the
temperature maps and quantitative assessment of several temperature/time plots at
four different locations.
Methods. A caries-free lower first molar cavity served as a natural tooth mold. Resin
composites were placed without intermediary adhesive. Two URPBF composites
(PFill; PFlow) and one pre-heated thermo-viscous bulk-fill composite (Viscalor: VC)
were compared to a contemporary bulk-fill composite (One Bulk Fill: OBF). Two
LED-LCU devices were used: Bluephase PowerCure (PC) and Elipar S10 (S10), with
three light-irradiation protocols (PC-3s, PC-10s and S10-10s). 2D temperature maps
over the entire coronal area were recorded for 120 s during and after irradiation using
a thermal imaging camera. Changes at four different levels were selected from the
data sets: (0, 2 and 4 mm from the cavity top and at 1 mm below the dentin cavity
floor). The maximum temperature attained (Tmax), the mean temperature rise (ΔT), the
time (s) to reach maximum temperature and the integrated areas (°C·s) under the
temperature/time (T/t) plots were identified. Data were analysed via three-way
ANOVA, One-way ANOVA, independent t-tests and Tukey post-hoc tests (p<0.05).
Results. All RBCs showed qualitatively similar temperature-time profiles. PFlow
reached Tmax in the shortest time. PC-3s (3000 mW/cm2) generated comparable ΔT to
S10-10s, except with PFill, where ΔT was greater. Despite the same irradiance (1200
mW/cm2), Elipar S10 led to higher Tmax and ΔT compared to PC-10s. The highest
Tmax and ΔT were observed at the 2 mm level, and the lowest were at 1 mm depth into
the underlying dentin.
Significance. Coronal 2D temperature maps showed rises largely confined within the
bulk-fill RBC materials, with maxima at 2 mm rather than 4 mm depth indicating
some extent of thermal insulation for the underlying dentin and pulp. RBCs
polymerized via different irradiation protocols showed similar temperature changes.
With the PC-3s protocol - also with pre-heated VC - minimal temperature rises at 1
mm within dentin suggest their clinical safety when sufficient remaining dentin
thickness is present.
U2 - 10.1016/j.dental.2021.06.008
DO - 10.1016/j.dental.2021.06.008
M3 - Article
SN - 0109-5641
VL - 37
SP - 1237
EP - 1247
JO - Dental Materials
JF - Dental Materials
IS - 8
ER -