Pre-Heating Effect on the Microhardness and Depth of Cure of Bulk-Fill Composite Resins

OBJECTIVE: The aim of this study was to investigate the effect of preheating three bulk-fill and one conventional composite resin on the Vickers microhardness and depth of cure of these composites. METHODS: In this study, three bulk-fill composites-SDR Plus (SDR), Estelite BULK FILL Flow (EST), Admira® Fusion x-tra (AFX), and one conventional composite resin G-ænial POSTERIOR (GP) were used as the control group. The samples were obtained at room temperature (24°C) and at 55°C in T2 mode after being placed in a heating device for 10 minutes. The samples were divided into eight groups (n=10) according to the type of material and heating process that was utilized (preheated and nonheated). All samples were tested with a Vickers microhardness (VHN) tester on the bottom and top surfaces. The first measurements were obtained at baseline; the second set of measurements was performed after the samples were stored in distilled water at 37°C for 24 hours. The depth of cure was calculated using a bottom/top hardness ratio of measurements. Statistical analysis was performed utilizing the SPSS V23 and Shapiro-Wilk tests. Lastly, the Duncan test was used for multiple comparisons (p<0.05). RESULTS: While the VHN increased after the preheating procedure in bulk-fill composites, it decreased in GP. There was no difference between the baseline and the 24-hour VHN values in SDR and GP. After 24 hours, while the VHN of EST increased, the VHN of AFX decreased. There was no difference between the hardness ratios of the AFX and EST samples (p<0.001) and hardness ratios were greater than GP and SDR. CONCLUSION: When comparing the baseline and the 24-hour values, the VHN depended on the type of materials. Sufficient curing depth was obtained in all groups with a thickness of 2mm.

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Investigation of the effect of different application techniques on microhardness in bulk-fill composite resins

International Dental Research ◽

10.5577/intdentres.2021.vol11.suppl1.6 ◽

2021 ◽

Vol 11 (Suppl. 1) ◽

pp. 32-37

Author(s):

Muhammet Fidan ◽

Hakan Yasin Gönder

Keyword(s):

Vickers Microhardness ◽

Composite Resin ◽

Native Speakers ◽

Composite Resins ◽

The Other ◽

Control Group ◽

Application Techniques ◽

Native Speakers Of English

Aim: The aim of this study was to investigate the effect of different application techniques on microhardness in one universal resin material and three different bulk-fill composite resin materials. Materials and Methods: In this study, one universal composite resin (Universal Restorative 200 [U], 3M-ESPE, USA) and three different bulk-fill composite resins (Filtek-One Bulk-Fill Restorative [F]; 3M-ESPE, USA: Tetric Evo-Ceram Bulk-Fill [E]; and Ivoclar-Vivadent, Liechtenstein; Tetric N-Ceram Bulk-Fill [N], Ivoclar-Vivadent, Liechtenstein) materials were used. A total of 60 disk-shaped samples, including 20 samples from each bulk-fill composite resin group, were prepared. The polymerization of the bulk-fill composite resins in one group was completed using a 2 mm (40 sec) + 2 mm (40 sec) incremental technique, and in the other group, it was completed using a 4 mm bulk technique (40 sec). The U composite resin (control group) polymerization was completed using a 2 mm + 2 mm (40 sec) incremental technique (n = 10). The Vickers microhardness (VHN) values of the samples were calculated. The data were analyzed with Kruskal–Wallis and Mann–Whitney U tests (p < 0.05). Results: Higher VHN values were found in the U composite resin compared to those in the bulk-fill composite resins (p < 0.05). In the bulk technique, a lower VHN value was observed in the N bulk-fill composite resin than in the control group (p < 0.05), while there was no difference between the N and E composite resin groups (p > 0.05). A lower N bulk-fill composite resin was observed in the groups in which the incremental technique was applied than in the control group (p < 0.05). When the techniques applied to the bulk-fill composite resins were evaluated within themselves, higher VHN values were observed in the E composite resin in the group in which the incremental technique was applied but not in the group in which the bulk was applied. Conclusion: It was observed that the content differences of composite resins were effective at different VHN values. The U composite resin (control) group showed higher VHN values than all the bulk-fill composite groups. How to cite this article: Fidan M, Gönder HY. Investigation of the effect of different application techniques on microhardness in bulk-fill composite resins. Int Dent Res 2021;11(Suppl.1):32-7. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.6 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

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Influence of Hydrogen Peroxide Bleaching Gels on Color, Opacity, and Fluorescence of Composite Resins

Operative Dentistry ◽

10.2341/11-189-l ◽

2012 ◽

Vol 37 (5) ◽

pp. 526-531 ◽

Cited By ~ 10

Author(s):

CRG Torres ◽

CF Ribeiro ◽

E Bresciani ◽

AB Borges

Keyword(s):

Hydrogen Peroxide ◽

Composite Resin ◽

Color Change ◽

Composite Resins ◽

Control Group ◽

Peroxide Bleaching ◽

Color Changes ◽

Tukey Test ◽

Bleaching Gels ◽

Bleaching Treatment

SUMMARY The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

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Effect of light-activation methods and water storage on the flexural strength of two composite resins and a compomer

Brazilian Oral Research ◽

10.1590/s1806-83242006000200010 ◽

2006 ◽

Vol 20 (2) ◽

pp. 143-147 ◽

Cited By ~ 8

Author(s):

Leonardo Eloy Rodrigues Filho ◽

Luis Antônio dos Santos Burger ◽

Silvia Kenshima ◽

José Roberto de Oliveira Bauer ◽

Igor Studart Medeiros ◽

...

Keyword(s):

Flexural Strength ◽

Composite Resin ◽

Water Storage ◽

Storage Period ◽

Multiple Comparisons ◽

Composite Resins ◽

Activation Method ◽

Light Activation ◽

Tukey Test ◽

Effect Of Light

The present study evaluated the flexural strength of three composite resins recommended for direct esthetic restorations: a polyacid modified composite (Dyract AP), a unimodal composite resin (Filtek Z250) and a hybrid composite resin (Point 4). The variation factors, apart from the type of composite resin, were the light activation method and the water storage period. The composite resins were light-cured in continuous mode (40 s, 500 mW/cm²) or in ramp mode (0-800 mW/cm² for 10 s followed by 30 s at 800 mW/cm²) and stored for 24 hours or 30 days in distilled water at 37°C. The data were analyzed by ANOVA and Tukey test for multiple comparisons (alpha = 0.05). The composite resin Z250 presented the highest mean flexural strength (166.74 MPa) and Dyract AP presented the lowest one (129.76 MPa). The storage for 30 days decreased the flexural strength in ramp mode (24 h: 156.64 MPa; 30 days: 135.58 MPa). The light activation method alone did not lead to different flexural strength values.

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Effect of Tooth-Whitening Procedures on Stained Composite Resins

Operative Dentistry ◽

10.2341/17-301-l ◽

2019 ◽

Vol 44 (1) ◽

pp. 65-75 ◽

Cited By ~ 3

Author(s):

JW Reinhardt ◽

MM Balbierz ◽

CM Schultz ◽

B Simetich ◽

MW Beatty

Keyword(s):

Red Wine ◽

Composite Resin ◽

Color Change ◽

Composite Resins ◽

The Other ◽

Time Interval ◽

Distilled Water ◽

Water Control ◽

Tooth Whitening ◽

Final Composite

SUMMARY In this laboratory study, a composite resin was stained to a visibly discernible level using both coffee and red wine over 14 days (change was considered clinically noticeable and significant when ΔEab*≥2.7). Color change was measured at one, three, seven, and 14 days of staining. Although the nature of color change was different for the two staining solutions, the overall degree of staining (ΔEab*) rendered by either coffee or wine at each time interval was not significantly different (p≥0.05). Four whitening protocols were applied to stained composites. Treatment included applications of distilled water (control), Crest Pro-Health [HD] toothpaste, Crest Whitestrips, Opalescence PF bleach (15%), and application of a fine pumice polishing (Preppies). HD toothpaste and Whitestrips were applied daily for 21 days, Opalescence was applied daily for 10 days, and polishing was applied once. Each of the whitening products, applied in a manner simulating at-home or in-office treatment, was effective in producing color improvements (lightening) over controls (p<0.05), but none of the four treatments produced lightening that was significantly different from the other treatments (p≥0.05). A comparison of final composite color with that measured at baseline showed that Opalescence returned composite color to an acceptable level following exposure to both staining solutions (ΔEab*<2.7), Whitestrips returned color close to baseline for wine-stained composites, and HD paste and polishing permitted residual stain to remain (ΔEab*≥2.7).

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Effect of irradiation mode and filling technique on resin/dentin bonding strength in class I cavities

Brazilian Oral Research ◽

10.1590/s1806-83242004000300015 ◽

2004 ◽

Vol 18 (3) ◽

pp. 260-265 ◽

Cited By ~ 4

Author(s):

Alex José Souza dos Santos ◽

Marcelo Giannini ◽

Luis Alexandre Maffei Sartini Paulillo ◽

José Roberto Lovadino ◽

Ricardo Marins de Carvalho

Keyword(s):

Bonding Strength ◽

Composite Resin ◽

Composite Resins ◽

Class I ◽

Control Group ◽

Human Teeth ◽

Dentin Bonding ◽

Soft Start ◽

Microtensile Testing ◽

Dunnett's Test

Factors such as light-curing mode, filling technique and cavity configuration may affect the bonding strength to dentin. This study evaluated the effect of irradiation mode and filling technique on resin/dentin bonding strength on the buccal wall of class I cavities in human teeth. Occlusal enamel was removed to expose a flat dentin surface. Occlusal cavities (4 x 3 x 3 mm) were prepared in dentin. The adhesive Single Bond was applied according to the manufacturer's instructions and TPH Spectrum composite resin was placed using the following: oblique incremental, horizontal incremental or bulk filling techniques. The composite resin was light-cured either by continuous (600 mW/cm² for 40 s) or Soft-Start (250 mW/cm² for 10 s + 600 mW/cm² for 30 s) modes. Specimens of the control group were obtained by bonding the material to the flat exposed buccal wall of the cavity (C-factor = 1). The teeth were stored in water at 37ºC for 24 h and prepared for microtensile testing. Bonded beams of approximately 0.8 mm² were obtained from the buccal wall and tested with a tension of 0.5 mm/min. Results were analyzed by two-way ANOVA, Tukey's test and Dunnett's test (alpha = 0.05). Incremental placement techniques with both irradiation modes produced higher bonding strength values than the bulk technique (p < 0.05). Bonding strength tested in the cavities had lower values than those obtained in flat dentin surfaces (control group) (p < 0.05), except for incremental fillings using stepped irradiation. Bonding strength to the cavity walls depends on the filling technique and on the irradiation mode of composite resins.

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Influence of additional polymerization in the microhardness of direct composite resins

Brazilian Dental Science ◽

10.14295/bds.2007.v10i2.333 ◽

2010 ◽

Vol 10 (2) ◽

Author(s):

Geraldo Henrique L. Lombardo ◽

Cristiane F. Carvalho ◽

Graziela Galhano ◽

Rodrigo Othávio A. Souza ◽

Lafayete N. Júnior ◽

...

Keyword(s):

Vickers Microhardness ◽

Resin Composite ◽

Saint Paul ◽

Metallic Matrix ◽

Composite Resins ◽

The Other ◽

Distilled Water ◽

Anova Test ◽

Tukey Test

Objective: To evaluate different methods of additional polymerization in the Vickers’ microhardness of three composite resins. Material and Methods: With assistance of a metallic matrix (3 x 4mm), 30 specimens (sps) of each direct resin composite (drc) were prepared, entitled: Filtek Z250(3M ESPE, Saint Paul/MN-USA)(Gr1), W3D(Wilcos, Petrópolis/ RJ-Brazil)(Gr2), and EstheticX (Dentsply/York/PA-USA)(Gr3). All sps were photopolimerized, by the incremental technique, during 40 seconds (Gr1 - n=10: control). After that, 20 samples of each group were divided and half of the samples (n=10) were submitted to the additional polymerization during 15 minutes to 127ºC in autoclave (Gr2) and the other half in stove (Gr3). After all sps were stored in distilled water (37ºC/24 hours). The microhardness was accomplished in digital machine (Future-Tech, FM 700 Model), with 50kg of load. The data obtained (Kg/mm2) were analyzed utilizing the ANOVA Test (2 factors) and Tukey test (p<0.05). Results: The values of mean ± standar deviations obtained were: Gr1a(84,2±5,1), Gr1b (71,6±6,7), Gr1c (89,6±7,4), Gr2a (101,1±6,0), Gr2b (96,4±9,0), Gr2c (112,6±7,3), Gr3a (74,0±6,5), Gr3b (66,0±12,7) e Gr3c (81,7±6,5). The polymerization in stove produced a higher microhardness than the other kinds of polymerization (p<0.05) and the microhardness of the resins statistically differed among them (p<0.05). Conclusion: The additional polymerization of the Filtek Z250 in the stove produced microhardness statistically higher than the others.

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Pengaruh kopi arabika terhadap perubahan warna resin komposit hybrid

e-GIGI ◽

10.35790/eg.5.1.2017.15294 ◽

2017 ◽

Vol 5 (1) ◽

Author(s):

Style V. Sirang ◽

P. S. Anindita ◽

. Juliatri

Keyword(s):

Hybrid Composite ◽

Composite Resin ◽

Composite Resins ◽

Control Group ◽

Control Group Design ◽

Arabica Coffee ◽

Group Design ◽

Hybrid Type ◽

Post Test ◽

One Way Anova

Abstract: Composite resin is one of the restorations used in the field of dentistry due to its good esthetic property. To date, the most commonly used composite resin is the hybrid type. Its weakness is the nature of fluid absorbance that can change its color. This discoloration can caused inter alia by food and beverage consumption. Arabica coffee is mostly consumed by our society, however, it has deposit of chlorogenic acid that might cause discoloration. This study was aimed to assess the influence of arabica coffee to the discoloration of hybrid composite resins. This was a true experimental study with a pre test and post test only control group design. Total samples were 24 composite resins of hybrid type (diameter 5 mm and height 2 mm). Each treatment group consisted of 6 samples. The samples were divided into 4 treatment groups, as follows: 0 day, 3 days, 5 days, and 7 days of immersion in arabica coffee solution. The one-way anova test showed that the influence of arabica coffee solution to discoloration of composite resins was significant (p=0.00). Conclusion: There was a significant influence of the duration of immersion in arabica coffee to discoloration of hybrid composite resinsKeywords: resin composite, discoloration, arabica coffee Abstrak: Resin komposit merupakan salah satu bahan restorasi yang sering digunakan di bidang kedokteran gigi karena memiliki nilai estetik yang baik. Saat ini jenis resin komposit yang sering digunakan yaitu resin komposit tipe hybrid. Resin komposit memiliki kekurangan yaitu sifat absorbansi cairan yang dapat menyebabkan perubahan warna. Salah satu penyebab perubahan warna yaitu makanan dan minuman. Kopi arabika merupakan minuman yang sering dikonsumsi oleh masyarakat dan memiliki kandungan asam klorogenik yang dapat memengaruhi perubahan warna. Penelitian ini bertujuan untuk mengetahui pengaruh kopi arabika terhadap perubahan warna resin komposit hybrid. Jenis penelitian ialaj eksperimental murni dengan pre test dan post test only control group design. Jumlah sampel penelitian yaitu 24 resin komposit tipe hybrid dengan ukuran diameter 5 mm dan tinggi 2 mm, dibagi dalam tiga kelompok. Masing-masing kelompok perlakuan terdiri dari 6 sampel. Sampel dibagi menjadi 4 kelompok yaitu kelompok perlakuan 0 hari, 3 hari, 5 hari, dan 7 hari perendaman dalam larutan kopi arabika. Hasil analisis data dengan uji one way Anova menunjukkan adanya pengaruh kopi arabika terhadap perubahan warna resin komposit (p=0,00). Simpulan: Terdapat pengaruh bermakna dari lama perendaman dalam kopi arabika terhadap perubahan warna resin komposit hybrid. Kata kunci : resin komposit, perubahan warna, kopi arabika

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Perbedaan Kekuatan Geser Reparasi Gigi Tiruan Cekat dengan Resin Komposit Packable dan Flowable (Uji Laboratoris pada permukaan logam NiCr)

Majalah Kedokteran Gigi Indonesia ◽

10.22146/majkedgiind.15533 ◽

2012 ◽

Vol 19 (2) ◽

pp. 102

Author(s):

Endang Wahyuningtyas ◽

Suparyono Saleh ◽

Sri Budi Barunawati

Keyword(s):

Bond Strength ◽

Shear Bond Strength ◽

Composite Resin ◽

Testing Machine ◽

Composite Resins ◽

Distilled Water ◽

Research Subjects ◽

Flowable Composite ◽

Diamond Bur ◽

Universal Testing

Latar Belakang. Resin komposit merupakan bahan pilihan untuk reparasi Gigi Tiruan Cekat porcelain fused to metal (PFM) Karena estetis baik dan manipulasi mudah. Tujuan penelitian ini adalah mengetahui perbedaan kekuatan geser perlekatan resin komposit pada permukaan logam Gigi Tiruan Cekat dengan menggunakan resin komposit jenis packable dan jenis flowable. Metode penelitian. Subjek penelitian berupa logam NiCr (Noritake, Japan) berbentuk silinder dengan diameter 10 mm dan tinggi 3 mm. Penelitian dibagi menjadi dua kelompok, masing-masing terdiri dari 10 subjek. Kelompok pertama reparasi dengan resin komposit packable (Z250™ 3M ESPE, USA) dan kelompok kedua reparasi dengan resin komposit flowable (Dyad flow, Kerr, USA). Permukaan subjek dikasari dengan wheel diamond bur, dietsa dengan asam fosfat 37 % (Scotchbond™, 3M ESPE, USA) kemudian dicuci dan dikeringkan, selanjutnya diaplikasikan silan (Rely X™ Ceramic Primer, 3M ESPE, USA) dan bonding (Adper™ Single Bond, 3M ESPE, USA). Permukaan kemudian dilapisi dengan resin komposit packable dan flowable, disinari selama 40 detik. Subjek penelitian direndam di dalam distilled water dan dimasukkan ke dalam incubator dengan suhu 37°C selama 7 hari. Uji kekuatan geser dilakukan dengan menggunakan Universal Testing Machine. Data dianalisis dengan uji t. hasil uji t menunjukkan terdapat perbedaan bermakna kekuatan geser reparasi gigi tiruan cekat pada permukaan logam (p<0,05). Kesimpulan penelitian ini adalah kekuatan geser reparasi pada permukaan logam dengan menggunakan resin komposit flowable yang mengandung bahan coupling agent lebih tinggi dibandingkan reparasi pada permukaan porselen dengan menggunakan resin komposit packable. Background. One of selected material by repairing the fixed partial denture was composite resin because of its good aesthetics and low manipulation. The aim. This research was aimed at identifying the differences of shear bond strength of composite resin on metal surface by using different composite resins, namely packable and flowable composite resins. Method. The research subjects were cylinders with 10 mm in diameter and 3 mm in height. The research subjects with metal material of NiCr (Noritke, Japan) involved two groups. The first group comprising 10 repair subjects with composite packable (Z250™, 3M ESPE, USA) and 10 repair subjects with flowable composite (Dyad flow, Kerr, USA). The surface of the subjects were roughned with wheel diamond bur and etched with 37% phosphate acid (Scotbond™, 3M ESPE, USA) were applied. The surface was then coated with packable and flowable composite resins and light-cured for 40 seconds. The research subjects were immersed in distilled water and put into the incubator at temperature of 37°C for 7 days. The shear bond strength test was conducted using the Universal Testing Machine. Data were analyzed using t-test. The result. The research result showed that there were differences of shear bond strength of repair between packable and flowable composite resins. The result of t-test indicated significant diffrences on metal surface (p<0,05). The conclusion of this research is that shear bond strength of repair with flowable composite which contain coupling agent has higher shear bond strength than that of packable composite resin.

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The Effect of Finishing and Polishing Procedures on the Surface Roughness of Composite Resin Materials

The Journal of Contemporary Dental Practice ◽

10.5005/jcdp-8-1-27 ◽

2007 ◽

Vol 8 (1) ◽

pp. 27-35 ◽

Cited By ~ 54

Author(s):

Nuray Attar

Keyword(s):

Surface Roughness ◽

Composite Resin ◽

Resin Composite ◽

Composite Resins ◽

Control Group ◽

Surface Groups ◽

Average Roughness ◽

Strip Surface ◽

Polishing Procedures ◽

Surface Sealant

Abstract Aims The aims of this study were to evaluate the effect of various finishing and polishing procedures on the surface roughness of six different composite resin materials (Artemis Enamel, TPH Spectrum, Filtek A–110, Filtek Supreme Enamel, Solitaire 2, and Filtek P–60) as well as to evaluate the effectiveness of the surface sealant application (BisCover) on the surface roughness after finishing and polishing procedures of tested composites. Methods and Materials Specimens (n=168) measuring 5 mm in diameter x 2 mm in thickness were fabricated in a plexiglass well covered with a Mylar strip using six composite resins. A control group of seven specimens of each material received no polishing after being cured under the Mylar strip. Twenty-one specimens for each composite were randomly divided among three finishing and polishing groups (n=7). Each group was polished using a different system: Carbide bur/Sof-Lex disc, Carbide bur/Enhance disc with polishing paste, and Carbide bur/Edenta composite finishing kit. The average surface roughness (Ra, ìm) of the control and treated specimens were measured with the Mitutoyo Surftest–402 Surface Roughness tester. After a surface sealant (BisCover) was applied to all treated specimens, according to manufacturer's instructions, the average roughness (Ra) was measured again. Results were statistically analyzed using analysis of variance (ANOVA) and the post-hoc Scheffe's test at a p<0.05 significance level. Results Significant differences were found for the surface roughness (p<0.05) with interaction among composite resins and the finishing systems used (p<0.05). Enhance/Biscover finishing and polishing procedure surface was not significantly different from the Mylar strip surface groups (p>0.05). The Mylar strip group was not significantly different from the Sof-Lex/BisCover and Edenta/BisCover groups. The ranking of mean Ra values by materials was as follows: Filtek Supreme Enamel < Filtek A110 < TPH Spectrum < Artemis <Filtek P–60 < Solitaire 2. The ranking of mean Ra values by polishing systems was as follows: Enhance/BisCover < Mylar Strip < Sof-Lex/BisCover < Edenta/BisCover < Sof-Lex < Enhance < Edenta. Conclusion Smoother surfaces were recorded for the Enhance/BisCover and the Mylar strip-formed surface groups. The composite finishing kit Edenta significantly increased the Ra for all tested composites (p<0.05). But after finishing with Edenta, the use of a surface sealant (BisCover) significantly improved the surface smoothness of all tested composites (p<0.05). Use of BisCover surface sealant on anterior and posterior resin composite restorations after finishing and polishing procedures is recommended. Citation Attar N. The Effect of Finishing and Polishing Procedures on the Surface Roughness of Composite Resin Materials. J Contemp Dent Pract 2007 January;(8)1:027-035.

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Effect of the photoactivation method on composite resin cure.

Clinical and Laboratorial Research in Dentistry ◽

10.11606/issn.2357-8041.clrd.2015.76207 ◽

2015 ◽

Vol 21 (3) ◽

pp. 156

Author(s):

Andrea Tami Abe ◽

Carina Sincler Delfino ◽

Kátia Martins Rode ◽

Miriam Lacalle Turbino

Keyword(s):

Vickers Microhardness ◽

Composite Resin ◽

Conventional Technique ◽

Composite Resins ◽

Polymerization Time ◽

Pulse Delay ◽

Soft Start ◽

Halogen Light ◽

Level Of Significance ◽

High Degree

For composite resins to obtain good properties, they must present a high degree of conversion and minimal polymerization contraction. To minimize this contraction, alternative photoactivation techniques have been suggested. The objective of this study was to compare the hardness of a photoactivated composite resin using the pulse-delay, soft start and continuous conventional technique, in thicknesses of 1, 2 and 3mm. The resin was activated with halogen light and the photoactivation time and intensity varied according to the technique. The samples were stored in an oven at 37ºC for one week and submitted to the Vickers microhardness test, on both the irradiated surface and the opposite surface. The results were submitted to ANOVA and the Tukey’s test with a level of significance of 5%. It was concluded that the hardness was higher with photoactivation of 40 seconds and for the techniques that had the same photoactivation time (20 seconds) there was no difference in terms of hardness. Therefore the hardness is not influenced by the technique, but rather, by the polymerization time.

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