Durafill VS Research Articles

Toxicity of Flow Line, Durafill VS, and Dycal to Dental Pulp Cells: Effects of Growth Factors

Introduction The objective was to determine the effects of growth factor treatment on dental pulp cell sensitivity to toxicity of 2 composite restoration materials, Flow Line and Durafill VS, and a calcium hydroxide pulp capping material, Dycal. Methods Toxicity of the dental materials to cultures of primary dental pulp cells was determined by the MTT metabolism assay. The ability of 6 different growth factors to influence the toxicity was tested. Results A 24-hour exposure to either Flow Line or Durafill VS caused approximately 40% cell death, whereas Dycal exposure caused approximately 80% cell death. The toxicity of Flow Line and Durafill VS was mediated by oxidative stress. Four of the growth factors tested (bone morphogenetic protein [BMP]-2, BMP-7, epidermal growth factor [EGF], and transforming growth factor [TGF]-β) decreased the basal MTT values while making the cells resistant to Flow Line and Durafill VS toxicity except BMP-2, which made the cells more sensitive to Flow Line. Treatment with fibroblast growth factor-2 caused no change in basal MTT metabolism, prevented the toxicity of Durafill VS, but increased the toxicity of Flow Line. Treatment with insulin-like growth factor-I (IGF-I) increased basal MTT metabolism and made the cells resistant to Flow Line and Durafill VS toxicity. None of the growth factors made the cells resistant to Dycal toxicity. Conclusions The results indicated that growth factors can be used to alter the sensitivity of dental pulp cells to commonly used restoration materials. The growth factors BMP-7, EGF, TGF-β, and IGF-I provided the best profile of effects, making the cells resistant to both Flow Line and Durafill VS toxicity.

Influence of NaHCO3 Powder on Translucency of Microfilled Composite Resin Immersed in Different Mouthrinses

The regular use of mouthrinses, particularly when combined with the use of air-powder polishing, could affect the appearance of tooth-colored restorations. The current study sought to evaluate the effect of NaHCO(3) powder on translucency of a microfilled composite resin immersed in different mouthrinses, at distinct evaluation periods. Eighty disk-shaped specimens of composite resin (Durafill VS, Heraeus Kulzer GmbH & Co. KG, Hanau, Germany) were prepared. The composite specimens were then randomly allocated into two groups according to the surface treatment: exposure to NaHCO3 powder (10 seconds) or nonexposure, and they were randomly assigned into four subgroups, according to the mouthrinses employed (N = 10): Periogard (Colgate/Palmolive, São Bernardo do Campo, SP, Brazil), Cepacol (Aventis Pharma, São Paulo, SP, Brazil), Plax (Colgate/Palmolive), and distilled water (control group). The samples were immersed for 2 minutes daily, 5 days per week, over a 4-month test period. Translucency was measured with a transmission densitometer at seven evaluation periods. Statistical analyses (analysis of variance and Tukey's test) revealed that: distilled water presented higher translucency values (86.72%); Periogard demonstrated the lowest translucency values (72.70%); and Plax (74.05%) and Cepacol (73.32%) showed intermediate translucency values, which were statistically similar between them (p > 0.01). NaHCO3 air-powder polishing increased the changes in translucency associated with the mouthrinses. Air-powder polishing alone had no effect on material translucency. Translucency percent was gradually decreased from 1 week of immersion up to 4 months. It may be concluded that the NaHCO3 powder and the tested mouthrinses have affected the translucency of microfilled composite resin, according to the tested time. During the last decade, the demand for composite resin restorations has grown considerably, however, controversy persists regarding the effect of surface roughness on color stability.

Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

This in vitro study evaluated the Knoop hardness of the composite resins Charisma (C) and Durafill VS (D) polymerized in 3 different conditions: at room temperature (A) (23 +/- 1 degrees C); refrigerated at 4 +/- 1 degrees C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 +/- 1 degrees C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (alpha=0.05). On the top surface, C(AI) was statistically similar to C(15I) and D(AI) to D(15I) (p>0.05). On the bottom surface, C(AI) presented higher hardness values when compared to COI and C(15I) (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C(7d) and D(7d) except for C(07d), which was not different from C(OI) at either surface (p>0.05). D(07d) showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

Effect of Bleaching on Roughness of Dental Composite Resins

This study investigated the effect of three bleaching agents (Whiteness Perfect, Whiteness Super, Whiteness HP) on roughness of three dental resin composites (Admira, Durafill VS, Gradia Direct). Twenty disk-shaped standard specimens (10 × 2 mm) of each composite material were prepared and divided into four subgroups (n = 5). In each resin composite group, the unbleached specimens served as control; the other specimens were bleached with one of the bleaching agents according to the manufacturer's instruction. Roughness values were assessed using the atomic force microscope and metallographic microscope. Two-dimensional and 3D images were also taken for detecting surface alterations of each specimen group. Although the surfaces of all specimens did not seem to be smooth, the unbleached control specimens showed more irregular areas compared with those of the bleached ones. Roughness values were decreased in bleached groups to some extent depending on the bleaching agents used.

In vitro toothbrushing abrasion of dental resin composites: packable, microhybrid, nanohybrid and microfilled materials

This study evaluated weight loss and surface roughening after toothbrushing of different resin composites: one packable (Solitaire 2, Heraeus Kulzer), one microhybrid (Charisma, Heraeus Kulzer), one nanohybrid (Simile, Pentron) and one microfilled (Durafill VS, Heraeus Kulzer). Cylindrical specimens (n = 20) were prepared. Half of the samples were submitted to 60,000 strokes, at 4 Hz, with a dentifrice-water slurry. Control samples (n = 10) remained stored at 37 degrees C. Pre- and post-abrasion parameters for weight (mg) and surface roughness (Ra, microm) were determined on an analytical balance and a surface profilometer. Data were separately submitted to Repeated Measures ANOVA and Tukey's test (a = 0.05). Percentages of weight loss were analyzed by ANOVA and Tukey's test (a = 0.05). The relationship between both evaluations was assessed by Pearson's test (a = 0.05). The means (%) for weight loss (standard deviation) were 0.65(0.2), 0.93(0.2), 1.25(0.6) and 1.25(0.4) for Simile, Durafill, Charisma and Solitaire, respectively. Baseline roughness means ranged from 0.065(0.01), 0.071(0.01), 0.066(0.02) and 0.074(0.01) for Simile, Durafill, Charisma and Solitaire, respectively, to 0.105(0.04), 0.117(0.03), 0.161(0.03) and 0.214(0.07) after testing. The composites with larger fillers presented higher weight loss and roughening than the finer materials (p < 0.05). For both evaluations, control specimens showed no significant alteration. No significant relationship between loss of weight and roughness alteration was detected (r = 0.322, p = 0.429).

Luminescence of selected dental composites in vitro

Objectives The work was motivated by the necessity to evaluate the emission changes of dental composites, as the emission under UV light is one of the important optical parameters of the hard tooth tissue. Methods Fulfill extra, Artemis and Durafill VS materials in A3.5 shade were tested. Coffee, tea, red wine and distilled water (blank) were used as staining drinks. The samples were soaked for 7 days. Total luminescence matrices were collected with an interval of 1 nm in emission and 10 nm in excitation, in the front-face geometry. Results The exposure of dental composites to staining drinks caused a reduction in luminescence intensity by up to 40%, the magnitude of the reduction depending on the drink and on the composite material. In the special case of the intrinsically weak fluorescent Durafill VS, the exposure to coffee apparently caused an increase in luminescence intensity due to coffee components adsorbed on the sample surface. Significance It is important to improve the emission stability of dental composites. The presently proposed methods are effective in evaluating the emission of dental composites. Emission needs to be tested in addition to color, as the two parameters are uncorrelated.

Shear strength evaluation of composite–composite resin associations

Objective The aim of this study was to investigate the shear strength between distinct associations of different commercial composite resins and their fracture modes. Methods Nine composite–composite associations ( n = 90) were prepared for shear strength evaluation and separated into the following groups: Z/Z (Filtek Z250 UD + Filtek Z250 A2); Z/D (Filtek Z250 UD + Durafill VS A2); Z/S (Filtek Z250 UD + Filtek Supreme YT); C/C (Charisma OA2 + Charisma A2); C/D (Charisma OA2 + Durafill VS A2); C/S (Charisma OA2 + Filtek Supreme YT); H/H (Herculite XRV B2D + Herculite XRV B2E); H/D (Herculite XRV B2D + Durafill VS A2); H/S (Herculite XRV B2D + Filtek Supreme YT). Shear tests were carried out using universal mechanical test equipment with a load of 200 kgf and speed of 0.5 mm/min. Ultimate shear strength data (MPa) from all tested groups were submitted to analysis of variance (one-way ANOVA) and the Tukey test. The fractured surfaces of the test samples were visually evaluated by binocular stereomicroscope at 20 times magnification. Fractures were classified as either adhesive or cohesive or mixed. Results The highest ultimate shear strength observed for composite–composite associations was found for the groups: Z/Z, C/S, H/H, H/S, Z/S and C/C. Those associations containing the Durafill resin were weaker than the others. Conclusion Microparticle RBC associations presented lower shear strength than hybrid and/or nanoparticle RBC associations, once the only significant difference was found when the Durafill resin was involved.

Effect of Bleaching on Color Change and Refractive Index of Dental Composite Resins

This study investigated the effects of three bleaching agents (Whiteness Perfect, Whiteness Super, and Whiteness HP) on the color change and refractive index of three dental composites (Admira, Durafill VS, and Gradia Direct). Twenty disk-shaped specimens (10 x 2 mm) of each composite were prepared and divided into four subgroups (n=5). An unbleached group was used as a control, while the remaining specimens in the three subgroups were bleached with one of the bleaching agents respectively. Color change was assessed according to CIELAB color system and refractive indices were determined by phase modulated spectroscopic ellipsometry. Color differences between bleaching and baseline value (DeltaE) were less than 3.3 for all groups. However, bleaching with Whiteness HP led to noticeable color changes for Admira and Durafill VS. While this agent had no effect on the refractive indices of these composites, the other two agents containing carbamide peroxide increased their refractive indices. Therefore, results suggested that replacement of such composite restorations may be required after bleaching.

Influence of different light curing units on the cytotoxicity of various dental composites

Objectives To evaluate the dependence of the toxicity of various dental composites on the use of high- and low-power light curing units (LCUs). Methods The composites Filtek Z 250, Durafill VS, Solitaire 2 and Grandio were polymerized using different light densities from three LCUs, namely Heliolux II, Swiss Master Light (SML) and a prototype LED. The toxicity of polymerized samples was tested by exposing them to the cell culture medium up to 28 days. The extracts of the composites were collected daily and used for incubation in human gingival fibroblasts cultures. Results Slow, low-intensity curing using the LED or the Heliolux II showed similar characteristics for all four composites, regarding the cell viability rate of human gingival fibroblasts. After 1 day of storage suboptimal results could be observed for the SML/Durafill and optimal results for SML/Grandio combination (approximately 100% cell viability). In addition, the composite Solitaire the SML yielded significantly better results than the other LCUs (cell viability, p ≤ 0.001: SML 60.5%, Heliolux 44.5%, LED 44.2%). Furthermore, the combination of the SML with Z 250 composite showed, after the first day and up to day 28, statistically significantly higher cell viability rates than the combination with the LED or Heliolux II. Significance This study shows that the combination of a high power LCU with some composites positively influences the HGF cell viability effected by the investigated composite extracts. Moreover, there is further indication that a reduction of composite toxicity is possible if the curing mode is adapted to the used composite.

Characterization of nanofilled compared to universal and microfilled composites

Objectives The purpose of this study was to compare the inorganic fraction and the mechanical properties of three nanofilled composites with four universal hybrid and two microfilled composites. The degrees of conversion of the materials photopolymerized using halogen and LED units were also investigated. Methods Three nanofilled (Supreme, Grandio and Grandio Flow), four universal hybrid (Point-4, Tetric Ceram, Venus, Z 100) and two microfilled (A 110, Durafill VS) composites were used in this study. Their filler weight content was measured by thermogravimetric analysis. The morphology of the filler particles was determined using scanning-electron microscopy (SEM). Mechanical properties were measured: dynamic and static elastic moduli, flexural strength and Vickers microhardness. The degree of conversion in relation with the depth of polymerization of every material tested was evaluated using Raman spectrophotometry. Results Nanofilled resin composites show higher elastic moduli than those of universal and microfilled composites, except for the Z-100. The microfilled composites exhibit by far the lowest mechanical properties. The flexural strength does not appear as a discriminating factor in this study. The degrees of polymerization obtained with the halogen lamp are higher than those obtained with the LED lamp. Significance Nanofilled resin composites show mechanical properties at least as good as those of universal hybrids and could thus be used for the same clinical indications as well as for anterior restorations due to their high aesthetic properties.

Relative curing degree of polyacid-modified and conventional resin composites determined by surface Knoop hardness

Objectives The aim of the present study was to investigate the relative curing degree at a depth of 2 mm of several polyacid-modified composites (PAM-Cs) as a function of shade. Methods The Knoop hardness of the irradiated top and non-irradiated bottom surfaces of 2 mm thick samples of the PAM-Cs Hytac, F2000, Glasiosite, Dyract, Dyract AP, and Compoglass F and of the resin composites Z100, Herculite Enamel XRV, and Durafill VS, were determined for shades A2 and A4. Results The top and bottom hardness of F2000 and Glasiosite ranged between that of the two composites Herculite and Z100. Compoglass, Dyract and Dyract AP had a lower top and bottom hardness than the hybrid composites, but higher than that of the microfilled composite Durafill. The top hardness of Hytac compared with that of the first group, whereas the bottom hardness compared with the second group. The bottom-to-top KHN ratio reflecting the relative curing degree at a depth of 2 mm was less than 80% for the two shades of Hytac and Compoglass as well as for the A4 shade of Dyract AP and Herculite. Significance A hard top surface of a PAM-C is not an indication of adequate in depth polymerization. Shade A2 results in significantly greater values for the curing degree compared to shade A4, the effect depending quantitatively on the formulation of the material. Some formulations of PAM-C do not reach an adequate curing degree at a depth of 2 mm so that it is recommended to apply the incremental technique even in box-only cavities with layers of maximum 2 mm.

Microhardness evaluation around composite restorations using fluoride-containing adhesive systems

The purpose of this study was to evaluate the microhardness of dental enamel around composite restorations bonded with fluoride-containing adhesive systems (FCAS), after thermo- and pH-cycling protocols. Standardized cylindrical cavities were prepared on enamel surfaces of 175 dental fragments, which were randomly assigned into seven experimental groups (n=25). Four groups used FCAS: Optibond Solo (OS); Prime&Bond 2.1 (PB); Syntac Sprint (SS) and Tenure Quick (TC). Other groups consisted of "Sandwich" technique restoration (STR) (glass ionomer liner + hydrophobic adhesive resin /restorative composite) or used Single Bond with (SB) or without (SBWC) cycling protocols. Adhesive systems were applied according to manufacturers' instructions and cavities were restored with a microfilled composite (Durafill VS). After finishing and polishing, all groups were submitted to 1,000 thermal cycles (5 ºC and 55 ºC) and to demineralization (pH 4.3) and remineralization (pH 7.0) cycling protocols, except for SBWC group. The Knoop microhardness of enamel surfaces were measured around restorations. Indentations were recorded at 150, 300 and 450-mm from the cavity wall. Data were analyzed by two-way ANOVA and Duncan's Test (a=0.05%). Means ± SD of enamel microhardness for the groups were (Kg/mm²): SBWC: 314.50 ± 55.93ª ; SB: 256.78 ± 62.66b; STR: 253.90 ± 83.6b; TQ: 243.93 ± 68.3b; OS: 227.97 ± 67.1c; PB: 213.30 ± 91.3d; SS: 208.73 ± 86.6d. Means ± SD of microhardness for the distances 150, 300, 450mm from the cavity wall were, respectively: 234.46 ± 77.81ª; 240.24 ± 85.12ª; 262.06 ± 79.46b. SBWC group, which was not submitted to thermo- and pH-cycling protocols, showed the highest enamel microhardness mean value and the FCAS resulted in lower microhardness values. At 450 mm from the cavity wall, the enamel microhardness increased significantly.

Effect of thermal cycling and filling technique on leakage of composite resin restorations

The objective of this study was to evaluate in vitro the effect on leakage of two incremental filling techniques and two composite resins with different elastic modulus and similar polymerization shrinkage. Eighty Class V cavities (4x4x2mm) were prepared in bovine incisors and were randomly restored with Z-250 (Z) or Durafill VS (D) + Single Bond in axial (a) or oblique (o) increments. The restorations were divided into two groups: Not Aged - N (4-hour-storage in water at 37ºC) and Aged - A (1-week storage in water at 37ºC + 1000 x - 5º-55ºC / 1-min dwell time). The specimens were covered with 2 coats of nail varnish so that only the restoration margins were exposed to silver nitrate 50% (2h) and developed under fluorescent light (8h). After they were sectioned twice in buccal-lingual direction, the four exposed surfaces were digitized (Vidcap) and the silver nitrate penetration was measured (ImageLab) at the incisal and gingival walls. Data were analyzed by a 3-way ANOVA (Resin, Filling Technique and Aging) separately for incisal and gingival walls (alpha=0.05). Resin and Aging were statistically significant either for the incisal and the gingival walls. The microfill composite resin infiltrated more than the hybrid composite. The thermal cycling caused an overall increase in silver nitrate penetration. The filling technique affected leakage depending on the composite resin and aging regimen.

Curing depth of (polyacid-modified) composite resins determined by scraping and a penetrometer

Objectives: The present study aimed to compare the curing depth of polyacid-modified composite resins (PAM-C) and some representative composite resins as a function of shade and post-cure using a scraping method and a penetrometer. Methods: The curing depth of the PAM-C Hytac, F2000, Glasiosite, Dyract, Dyract AP, and Compoglass F and of the composite resins Durafill VS and Z100 were determined for shade A2 and A4 using a scraping method based on ISO 4049:2000 and a digital penetrometer. Samples were light-cured (800 mW/cm 2 at 40 s) in bulk in split stainless steel molds. Immediately after light-curing or after a 24 h post-cure, the height of the cylinder of cured material was measured and taken as the curing depth. Results: For both test methods, the curing depth was independent of post-cure ( P≥0.05), but differed significantly among materials and shade ( P<0.001). Moreover, there was a significant interaction between the latter ( P<0.001). Regression analysis generally demonstrated that there was no significant systematic or proportional difference between the test methods. The curing depths of the PAM-C F2000 and Glasiosite were comparable to that of the hybrid composite Z100, but greater than the curing depth of the microfilled composite Durafill VS. The PAM-C Dyract AP, Dyract, Compoglass F and Hytac had a curing depth smaller than that of the microfilled composite. Significance: The scraping method based on ISO 4049:2000 and a digital penetrometer give comparable curing depths for PAM-C. The curing depth greatly varies among the materials and can be considerably smaller than that of a microfilled composite resin. Shade A2 results in significantly greater values for the curing depth compared to shade A4, the effect depending quantitatively on the formulation of the material.

Sliding wear of 19 commercially available composites and compomers

Objectives. The aim of this study was to determine the influence of particle size, particle material and morphology on the sliding wear of 19 light curing, commercially available composites (Durafill VS, Metafil CX, Heliomolar RO, Solitaire, Arabesk, Artglass, Charisma F, Pertac II, Charisma, Degufill Ultra, TPH Spectrum, Z100, Tetric classic, Pertac Hybrid, Estilux Hybrid, Dyract AP, Compoglass F, Compoglass and Hytac). Methods. The materials were applied to an aluminum sample holder (7.5 mm diameter, 2 mm depth) in one layer and polymerized in a Dentacolor XS light curing unit for 180 s. The surface was ground flat (#1000) to remove any matrix rich surface layer. Then samples were stored in Ringer's solution for 24 h at 37 °C. Occlusal contact wear was simulated in a sliding wear tester (Munich Artificial Mouth). Eight specimens of each material were tested in a pin-on-block design with oscillating sliding of a Degussit antagonist (5 mm diameter) at a vertical load of 50 N. The horizontal excursion of the antagonist was 8 mm. Wear was quantified by a replica technique every 6000, 10,000, 30,000 and 50,000 cycles using a 3D-laser scanner. The materials were compared by their mean wear after 50,000 cycles. Comparisons of different composites and compomers were performed using analysis of variance and t-tests including the Bonferroni correction. Results. The microfiller composites (Durafill VS, Metafil CX, Heliomolar RO) revealed the lowest, and the compomers (Dyract AP, Compoglass F, Compoglass and Hytac) showed the highest contact wear ( p<0.05). The wear of the hybrid composite (Estilux Hybrid) and the micro hybrid composites (Solitaire, Arabesk, Artglass, Charisma F, Pertac II, Charisma, Degufill Ultra, TPH Spectrum, Z100, Tetric classic, Pertac Hybrid) was higher than that of the microfiller composites ( p<0.05). The results showed additional significant differences within the three groups of composites. The coefficient of determination between loss of height and maximum particle size was r 2=0.41. Significance. Both particle size and morphology have a high influence on the wear properties concerning the two-body wear in the occlusal contact area.

The effect of thermocycling on microleakage of several commercially available composite Class V restorations in vitro

Statement of the problem Microleakage is a major factor contributing to the occurrence of secondary carious lesions around composite restorations. Purpose of study This in vitro study investigated the effect of thermocycling on microleakage of several composite Class V restorations. Material and methods One hundred twenty molars were randomly distributed into 6 groups of 20 teeth. Class V preparations were made in the buccal and lingual surfaces of each tooth and restored in bulk by use of 6 composites (Arabesk, Silux-Plus, Solitaire 2, Durafill VS, Charisma, and Renew) according to the manufacturers’ recommendations. The teeth were stored in distilled water at room temperature for 24 hours. The teeth in each group were divided randomly into 2 subgroups: (a) thermocycled for 500 cycles between 5° and 55°C with a dwell time of 30 seconds, (b) no thermocycling treatment. All restored teeth were immersed in 1% methylene blue dye for 4 hours and sectioned buccolingually with a diamond wheel. Dye penetration was scored by use of a stereomicroscope at original magnification ×4. The generalized linear models statistical analysis was used (α=.05). Results The preparation margins (enamel/dentin) and thermocycling had a significant effect on microleakage ( P=.0351, P<.0001, respectively); the type of material had no significant effect ( P=.1689). Conclusions Thermocycling significantly increased the microleakage ( P<.0001). The overall microleakage at the enamel margins was significantly less than at the dentinal margins ( P=.0351).

PHYSICAL PROPERTIES OF COMPOSITES CURED WITH CONVENTIONAL LIGHT OR ARGON LASER

ABSTRACT Objective: This study evaluated various physical properties of two resin composites polymerized by either an argon laser or a conventional visible light. Materials and Methods: A hybrid composite, Herculite XRV (Kerr Corp., Orange, California), and a microfill composite, Durafill VS (Kulzer, Wehrheim, Germany), were used in this study. Three physical properties, diametral tensile strength, compressive strength, and flexural strength, were tested. Five specimens of each composite resin were made for each set of physical properties tested, for a total of 18 groups and 90 specimens. Specimens were fabricated according to the American National Standards Institute and American Dental Association Specification No. 27 for each property tested. The composite was polymerized with either an argon laser (power density of 1000 mW/cm2) for 10 or 20 seconds or a conventional visible light (power density of 354 mW/cm2) for 40 seconds. Specimens were stored in water in light‐proof containers at 37°C for 7 days before testing with a Zwick (Atlanta, Georgia) universal testing machine. Results: The physical properties of Herculite XRV were not affected by the light source or exposure time. For Durafill VS, no significant differences were observed for the diametral tensile strength whether the argon laser or conventional light was used. However, the flexural strength of the microfill was significantly lower when polymerized with the argon laser a t 10 seconds compared with the two other curing methods (20‐second laser cure, 40‐second conventional cure). Also, the compressive strength of Durafill VS polymerized with the argon laser a t 10 seconds was significantly lower than when it was cured with the conventional light for 40 seconds. Conclusions: Hybrid and microfill resin composites cured with an argon laser for 20 seconds had physical properties comparable to composites polymerized with a conventional visible light unit for 40 seconds. Therefore, with adequate exposure time, the argon laser is a potential alternative to conventional visible light‐curing.