Effect of Moving the Tip of the Light Curing Unit on the Irradiance Value Delivered.

Objective: To determine the effect of differences in the distances and radial positions of the tips of Light-Curing Units (LCU) on the irradiance values delivered.

Materials And Methods: Four LCUs-Valo X, Emitter A, CuringPen, and Pinkwave were tested at different distances from the tip (0, 2, 4, 6, 8 mm) and radial displacements (2 and 4 mm East, West, North, South). The radiant power (mW) and emission spectrum (mW/nm) were measured using an integrating sphere with a 4 mm aperture.

Effect of thickness and irradiance on the polymerization delay at the bottom surface of light-cured resin composites.

Objective: To examine the effects of the resin-based composite (RBC) thickness and incident irradiance on the time delay after the light turns on before polymerization starts at the bottom surface of the RBC.

Methods: The degree of conversion (DC) was determined using Fourier-transform infrared spectroscopy (FT-IR) at a rate of 13 measurements per second. Six commercial RBCs were tested at three thicknesses (0.

Impact of high irradiance and short exposure times on the polymerization kinetics of sculptable and flowable bulk-fill composites.

Objective: To determine the presence of exposure reciprocity in nine resin-based composites (RBCs) using fast (3 s, high irradiance) or standard light-curing modes for 10 s, 20 s, or 30 s.

Methods: Five sculptable and four flowable bulk-fill RBCs were light-cured using a Bluephase PowerCure light-curing unit (LCU). The RBCs were divided into groups according to the exposure modes tested: fast (3 s mode - at 3130 mW/cm), or for the manufacturer's recommended time on the standard (High mode at 1226 mW/cm).

Effect of a 4 mm vs. a 6 mm Diameter Mold on the Depth of Cure of 6 Bulk-Fill Resin-Based Composites.

Dental researchers and manufacturers use the ISO 4049 standard to determine the depth of cure (DoC) of resin-based composites (RBCs). This standard uses a 4 mm diameter stainless-steel mold and subsequently divides the length of the remaining hard RBC by 2. However, the DoC values obtained using this mold have been challenged.

Effect of using curing light manufacturer-recommended exposure times on the microhardness of resin composites.

Objectives: This study evaluated the effect of the light curing unit (LCU), light curing technique (LCT), and insertion technique (CIT) of resin-based composite (RBC) on the microhardness at various depths of RBC specimens.

Methods: A mesio-occlusal-distal (MOD) mold was used to make samples of conventional RBC (n = 3/group) using either an incremental (I) or a bulk-fill (BF) technique. The RBC was photocured using one of three different LCUs (Bluephase Style 20i for 15 s (I) and 10 s (BF), Monet laser for 1 s (I) and 3 s (BF), and Pinkwave for 10 s (I) and 20 s (BF).

Influence of temperature and primer application on setting time and degree of conversion of a dual-cure self-adhesive cement.

Objectives: To examine the in vitro effect of different temperatures and use of a primer on the setting time (ST) and degree of conversion (DC) of a novel dual-cure self-adhesive cement (Set Maxx, SDI Limited).

Methods: Set Maxx was tested alone or with Stela Primer (SDI), both with light curing (LC) for 20 s with the Valo X (Ultradent), or it was allowed to self-cure (SC). The ST was determined according to ISO 4049 (n = 5).

Effect of damage or contamination to the tips of 200 light-curing units.

Objective: The light-curing unit (LCU) has become a vital piece of dental equipment that must be correctly maintained. This study investigated the impact of contamination and physical damage to the light tip on the power and radiant emittance values from old and new LCUs.

Materials And Methods: Two investigators assessed 200 LCUs in dental clinics.

Physicomechanical properties of resin-based composites photo-polymerized using laser, polywave and quadwave curing lights.

Objectives: This study evaluated the fracture toughness (K), energy absorption E and Vickers hardness (VH) of resin-based composites (RBC) photo-polymerized with new light curing unit (LCU) technologies: one laser diode (Monet Laser - AMD Lasers), one polywave™ LED (PowerCure - Ivoclar) and one quadwave LED (PinkWave - Apex).

Methods: Two conventional: Evo, Tetric EvoCeram (Ivoclar) and FS, Filtek Supreme (Solventum); and two bulk-fill: PF, PowerFill (Ivoclar) and AF, Admira Fusion x-tra (VOCO) were tested. The RBC specimens were photo-polymerized for 1 second with the Monet, 3 seconds with the PinkWave in the 3-second-high output mode, and the 10-second standard mode using the PowerCure light.

Effect of Three Heating Guns on the Temperature of Two Bulk-Fill Resin-Based Composites.

Objective: To evaluate the effect of three heating guns-Phasor (Vista Apex, Racine, USA), VisCalor (VOCO, Cuxhaven, Germany), and Compex HD (AdDent Inc. Danbury, USA)-on the temperature changes of two bulk-fill resin-based composites (RBCs): VisCalor Bulk (VBF, VOCO) and Filtek One Bulk Fill Restorative (OBF, Solventum, St. Paul, USA).

Evaluation of a quadwave curing light compared to a dual-peak LED curing light.

Objective: To determine if the PinkWave (PW) light-curing unit (LCU) that emits red and infrared (IR) light as well as violet and blue light improves the depth of cure and degree of conversion (DC) of resin-based composites (RBCs).

Methods: The DC of RBCs at various distances was calculated from data collected at a rate of 13 Hz using attenuated total reflectance Fourier-transform infrared spectroscopy. To assess the contributions of the different wavelengths of light, optical filters were used to block the red and IR light from the PW.

Effect of beam divergence on the irradiance from dental light curing units.

Objective: This study measured the beam divergence angle and light output from dental light curing units (LCUs). Twenty LCUs were assessed using a laboratory-grade wide beam imager to determine the relationship between the beam divergence on the irradiance as a function of distance from the light tip.

Methods: The irradiance (mW/cm) and beam divergence angles (°) at 5, and 10 mm from the tips of 18 Light-Emitting Diode (LEDs), 1 Quartz-Tungsten-Halogen (QTH), and 1 Laser diode LCU.

Effect of Indenter Load on Vickers Microhardness and Indentation Depth of One Resin Composite.

The load and size of the indentation may affect the hardness value. This study investigated the effect of the indentation size on the microhardness of one resin-based composite (RBC). Metal molds 4 mm deep and 12 mm in diameter were filled with Tetric EvoCeram Bulk Fill (Ivoclar) and light-cured for 10 s using a broad-spectrum LED curing light.

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.

Opalescence and Fluorescence of 46 Resin-Based Composites Exposed to Ultraviolet Light.

Identifying the boundary between the tooth and the resin-based composite (RBC) is difficult when replacing restorations. Ultraviolet (UV) light has been reported to assist the viewer by causing the RBC to fluoresce. Using a laboratory-grade fiberoptic spectrometer, 46 RBCs were exposed to UV light from the Woodpecker O-Star curing light.

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.

Evaluation of the information provided in the instruction manuals of dental light-curing units.

Objective: This study evaluated the completeness and accuracy of information in LCU instruction manuals from 40 manufacturers.

Materials And Methods: Instruction manuals from 40 LCUs (20 from leading manufacturers and 20 budget units) were reviewed. Twenty-eight parameters across five categories were assessed using a binary scale (0=incorrect/missing, 1=correct).

Effect of high irradiance and short exposure times on the depth of cure of six bulk-fill resin composites.

This study examined the effect of high irradiance and short exposure times on the depth of cure of six resin-based composites (RBCs). Bluephase PowerCure and the Valo X light-curing units (LCUs) were used to photocure bulk-fill RBCs for their recommended exposure times: Admira Fusion x-tra (AFX/20s), Aura Bulk Fill (ABF/20s), Filtek One Bulk Fill (FOB/20s), Opus Bulk Fill APS (OBF/30s), Tetric EvoCeram Bulk Fill (TEC/10s) and Tetric PowerFill (TPF/10s). In addition, all bulk-fill RBCs were tested for depth of cure with one short 3 s exposure time from the Bluephase PowerCure or the Valo X in the Xtra Power mode.

Thermography and conversion of fast-cure composite photocured with quad-wave and laser curing lights compared to a conventional curing light.

Objectives: This study investigated effects of the different emittance-mode protocols from three light curing units (LCUs): (i) a Laser (Monet); (ii) a quad-wave (PinkWave); (iii) a conventional LED (Elipar S10) on the temperature rise (ΔT) and degree of conversion (DC) when photo-curing fast or conventional bulk-fill resin-based composites (RBC). The aim was to correlate ΔT and DC, and the radiant exposure delivered to RBC specimens.

Methods: A 3D-printed resin mold of 4 mm depth was filled with two bulk-fill RBCs: Tetric PowerFill® (fast photo-polymerised composite) (TPF) or Tetric EvoCeram® Bulk-Fill (EVO).

Effect of thickness and shade of CAD/CAM composite on the light transmission from different light-curing units.

The thickness and shade of a restoration will affect the transmission of light from the light-curing unit (LCU). This study determined the power (mW), spectral radiant power (mW/nm), and beam profile of different LCUs through various thicknesses and shades of a CAD-CAM resin composite (BRAVA Block, FGM). Five thicknesses: 0.

Effect of four different mono and multi-wave light-curing units on the Knoop hardness of veneer resin composites.

Objectives: To evaluate the effect of mono and multi-wave light-curing units (LCUs) on the Knoop hardness of resin-based composites (RBC) that use different photoinitiators.

Methods: Central incisor-shaped specimens 12 mm long, 9 mm wide, and 1.5 mm thick were made from 2 RBCs that use different photoinitiators: Tetric N-Ceram (Ivoclar Vivadent) - and Vittra APS (FGM), both A2E shade.

Effect of Tooth Brushing Cycles and Dentifrice Fluoride Concentration on a Glazed CAD/CAM Ceramic.

Purpose: To evaluate the effect of tooth brushing and dentifrice fluoride (F-) concentration on changes in color and translucency (ΔE00 and ΔT00, respectively), surface gloss (GS), surface roughness (Sa), and microstructure of a glazed CAD/CAM ceramic.

Materials And Methods: Ceramic blocks (e.max/CAD) were sectioned into rectangular plates (14 x 12 x 1 mm), and one surface of each sample was glazed.

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.

Surface properties and Streptococcus mutans biofilm adhesion of ion-releasing resin-based composite materials.

Objective: To evaluate the adhesion of Streptococcus mutans (S. mutans) and related surface properties of ion-releasing resin-based composite (RBC) restorative materials.

Methods: Two ion-releasing RBCs, Activa (ACT) and Cention-N (CN), were compared to a conventional RBC (Z350) and a resin-modified glass ionomer cement (Fuji-II-LC).

Skill Retention of Light-Curing Technique Using Only Verbal Instructions versus Using an Instructional Video: A 2-Year Follow-Up Study of Dental Students.

Purpose: To evaluate the retention of light-curing skills among dental students after two years of clinical experience and determine if there are any differences in the skills retention between students who received verbal instructions or those who had received an instructional video. The students' satisfaction with past learning, self-confidence, and general knowledge about light-curing were also evaluated.

Methods: This study is a 2-year evaluation of previous work.

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.