Letter to the Editor.

The authors wish to acknowledge that the information on the Monet website⁹ has now changed (2024) to reflect that exposures longer than 3 seconds are required for larger restorations and that overlapping exposures should be used. The website now states that for preparation areas that are larger than 5mm in depth and 8mm in diameter, two overlapping spot cures of 3 seconds are recommended (Figure 2). The single 1 and 3x1- second exposure times used in the article are not recommended by the manufacturer and should now be considered 'off-label' use of the Monet.

Ability of a novel primer to enhance the polymerization of a self-cured resin composite.

Objective: This study evaluated the degree of conversion (DC), polymerization kinetics, and temperature of a new self-cure bulk-fill resin-based composite (Stela Automix, SDI).

Methods: The study was divided into seven groups: (1) Stela Primer, (2) Stela Automix, (3) Stela Automix exposed to light for 20 s after 100 s, (4) Stela Primer with Stela Automix, (5) Stela Primer with Stela Automix and exposed to light for 20 s after 100 s, (6) Scotchbond Universal with Stela Automix, and (7) Scotchbond Universal with Stela Automix and exposed to light for 20 s after 100 s. The real-time reaction rates and DC at the bottom of 2 mm thick specimens at ∼32 °C were measured at 720 s after insertion using a spectrometer with an Attenuated Total Reflectance detector.

The dark art of light curing in dentistry.

Objective: This study was designed to show that the commonly reported irradiance values that are quoted in most publications inadequately describe the light output from light curing units (LCUs).

Methods: The total spectral radiant power (mW) output from 12 contemporary LCUs was measured with a fiberoptic spectroradiometer and a calibrated integrating sphere. Five recordings were taken for each LCU and exposure mode.

Effect of a 3-second Off-label Exposure on the Depth of Cure of Eight Resin-based Composites.

Objectives: This study evaluated the depth of cure (DoC) of eight resin-based composites (RBCs) photocured using one multipeak light-curing unit (LCU) on the standard output setting for the manufacturer's RBC recommended exposure time and at a higher irradiance for 3 seconds.

Methods: Three conventional RBCs: Tetric EvoCeram (Evo), Tetric N-Ceram (Cer), Tetric Prime (Pri); and five bulk-fill: Tetric N-Ceram Bulk Fill (CerBF), Opus Bulk Fill APS (OpusBF), Opus Bulk Fill Flow APS (OpusF), Tetric PowerFill (PFill) and Tetric PowerFlow (PFlow) were examined. Only PFill and PFlow are formulated to be photocured in 3 seconds.

Ability of Six Curing Lights to Photocure Four Resin-Based Composites in a MOD-Mold: A Double-Blind Study.

Objective: The ability of six curing lights to photocure four resin-based composites (RBCs) in a mold simulating a cavity was compared visually.

Materials And Methods: Four RBCs were photocured using the: Woodpecker B for 2x10s, SmartLite Pro 2x10s, Valo Cordless 2x10s, Valo Cordless 2x3s Xtra power, Valo X 2x10s, Valo X 2x5s Xtra power, PowerCure 2x3s mode, Monet 1x1s and Monet 3x1s, in a mold representing a molar Class II restoration. Immediately after photocuring, the RBC specimens were immersed in a solvent to remove the uncured RBC, after which they were photographed and de-identified.

Evaluation of 278 New Bluephase Style Light Curing Units Purchased Over Six Years.

Objective: This study measured 278 new curing lights (LCUs) to determine if they met the manufacturer's specifications.

Materials And Methods: Over a 6-year period, the light output from 278 Bluephase Style LCUs was measured before the LCUs were given to students (41 in 2017, 44 in 2018, 46 in 2019, 48 in 2020, 50 in 2021, and 49 in 2022). The radiant exitance (mW/cm²) from each year was compared using ANOVA and Tukey- Kramer multiple comparisons test with adjustment for the unequal sample sizes (α=0.

Irradiance from 12 LED light curing units measured using 5 brands of dental radiometers.

Objective: To evaluate the accuracy of five brands of radiometers in reporting the irradiance (mW/cm ) from twelve brands of LCUs compared to a 'Gold Standard' (GS) reference obtained from a hand-held laboratory-grade radiometer.

Materials And Methods: The irradiance was measured from two examples of twelve brands of previously used LCUs on two examples of five brands of dental radiometers. The emission spectrum was also obtained.

Ability of short exposures from laser and quad-wave curing lights to photo-cure bulk-fill resin-based composites.

Objective: This study investigated the ability of a laser, and a 'quad-wave' LCU, to photo-cure paste and flowable bulk-fill resin-based composites (RBCs).

Methods: Five LCUs and nine exposure conditions were used. The laser LCU (Monet) used for 1 s and 3 s, the quad-wave LCU (PinkWave) used for 3 s in the Boost and 20 s in the Standard modes, the the multi-peak LCU (Valo X) used for 5 s in the Xtra and 20 s in the Standard modes, were compared to the polywave PowerCure used in the 3 s mode and for 20 s in the Standard mode, and to the mono-peak SmartLite Pro used for 20 s.

In-vitro pulpal temperature increases when photo-curing bulk-fill resin-based composites using laser or light-emitting diode light curing units.

Objective: To evaluate the in vitro pulpal temperature rise (ΔT) within the pulp chamber when low- and high-viscosity bulk-fill resin composites are photo-cured using laser or contemporary light curing units (LCUs).

Materials And Methods: The light output from five LCUs was measured. Non-retentive Class I and V cavities were prepared in one upper molar.

A Blinded Comparative Study of Four Commercially Available LEDs and a Laser Light Curing Device.

Objective:  This study determined the effectiveness of five light-curing units (LCUs; four light-emitting diode [LED] and one laser) used on different settings to photo-activate four conventional resin-based composites (RBCs).

Materials And Methods:  A total of 108 RBC specimens were photo-activated in a white Delrin mold representing a mesial-occlusal-distal (MOD) class II restoration in a molar tooth. The proximal boxes were 5 mm deep, and the mesial-distal length was 12 mm.

In vitro temperature changes in the pulp chamber caused by laser and Quadwave LED-light curing units.

The study evaluated the pulp temperature (PT) increase in Class I and V preparations when exposed to the Monet Laser (for 1 and 3 s), the PinkWave (for 3 and 10 s), the Valo Grand (for 3 and 10 s), the PowerCure, (for 3 and 10 s) and the SmartLite Pro (for 10 s). Non-retentive Class I and Class V cavities were prepared in one molar fixed in an acrylic plate and positioned in a warm water bath. The PT baseline was kept at 32 °C to simulate physiological conditions.

Temperature changes and hardness of resin-based composites light-cured with laser diode or light-emitting diode curing lights.

The temperature and Vickers Hardness (VH) at the top and bottom surfaces of three resin-based composites (RBCs) were measured when light-cured using five light-curing units (LCUs). The spectrum, power, and energy delivered to the top of the RBCs and transmitted through the RBCs were measured. Starting at 32℃, the temperature rise produced by the Monet Laser (ML-1 s and 3 s), Valo Grand (VG-3 s and 10 s), DeepCure (DC-10 s), PowerCure, (PC-3 s and 10 s) and PinkWave (PW-10 s) were measured at the bottom of specimens 2 mm deep × 6 mm wide made of Filtek Universal A2, Tetric Evoceram A2 and an experimental RBC codenamed Transcend UB.

Power output from 12 brands of contemporary LED light-curing units measured using 2 brands of radiometers.

Background: Given the increasing use of photo-activated resins in dentistry, dentists and researchers need a user-friendly dental radiometer to measure the power output from dental light-curing units (LCUs).

Objective: Our goal was to measure the accuracy of two brands of dental radiometers in reporting the power (mW) from twelve brands of contemporary LCUs compared to a 'gold standard' (GS) reference value obtained from an integrating sphere attached to a fiberoptic spectroradiometer.

Methods: The power output was measured from two units of 12 brands of LCUs, five times on the ''GS" system, five times on two Bluephase Meter II dental radiometers, and five times on two Mini Gig hand-held spectroradiometers.

Depth of cure of 10 resin-based composites light-activated using a laser diode, multi-peak, and single-peak light-emitting diode curing lights.

Objectives: To evaluate the depth of cure (DOC) of ten contemporary resin-based composites (RBCs), light-cured using different LCUs and exposure times.

Methods: The power, radiant emittance, irradiance, radiant exposure (RE), and beam profiles from a laser (M, Monet), a multi-peak (V, Valo Grand), and single-peak (S, SmartLite Pro) LCU were measured. The DOC was measured using a 6-mm diameter metal mold and a solvent dissolution method to remove the uncured RBC.

In Vivo Pulp Temperature Changes During Class V Cavity Preparation and Resin Composite Restoration in Premolars.

Objective: This in vivo study evaluated the influence of the sequence of all restorative steps during Class V preparation and restoration in human premolars on pulp temperature (PT).

Methods And Materials: Intact premolars with orthodontic extraction indication of 13 volunteers received infiltrative anesthesia and isolation with rubber dam. An occlusal preparation was made with a high-speed diamond bur under air-water spray until the pulp was minimally exposed, then a thermocouple probe was inserted within the pulp.

Comparison of in vivo and in vitro models to evaluate pulp temperature rise during exposure to a Polywave® LED light curing unit.

Objectives: To measure and compare in vivo and in vitro pulp temperature (PT) increase (ΔTEMP) over baseline, physiologic temperature using the same intact upper premolars exposed to the same Polywave® LED curing light.

Methodology: After local Ethics Committee approval (#255,945), local anesthesia, rubber dam isolation, small occlusal preparations/minute pulp exposure (n=15) were performed in teeth requiring extraction for orthodontic reasons. A sterile probe of a temperature measurement system (Temperature Data Acquisition, Physitemp) was placed within the pulp chamber and the buccal surface was sequentially exposed to a LED LCU (Bluephase 20i, Ivoclar Vivadent) using the following exposure modes: 10-s low or high, 5-s Turbo, and 60-s high.

Controlling , Human Pulp Temperature Rise Caused by LED Curing Light Exposure.

Objective: The objective of this study was to evaluate the effectiveness of air spray to reduce pulp temperature rise during exposure of intact premolars to light emitted by a high-power LED light-curing unit (LCU).

Methods And Materials: After local Ethics Committee approval (#255945), intact, upper first premolars requiring extraction for orthodontic reasons from five volunteers received infiltrative and intraligamental anesthesia. The teeth (n=9) were isolated using rubber dam, and a minute pulp exposure was attained.

Analysis of temperature increase in swine gingiva after exposure to a Polywave LED light curing unit.

Objective: This study evaluated the temperature increase in swine gingival temperature after exposure to light emitted by a Polywave LED light curing unit (LCU, Bluephase 20i, Ivoclar Vivadent).

Methods: After local Ethics Committee approval (protocol 711/2015), 40 pigs were subjected to general anesthesia and the LCU tip was placed 5mm from the buccal gingival tissue (GT) close to lower lateral incisors. A thermocouple probe (Thermes WFI, Physitemp) was inserted into the gingival sulcus before and immediately after exposure to light.