scholarly journals Effect of the Time of Salivary Contamination during Light Curing on Degree of Conversion and Microhardness of a Restorative Composite Resin

Biomimetics ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 23 ◽  
Author(s):  
Rasoul Sahebalam ◽  
Alireza Boruziniat ◽  
Fahimeh Mohammadzadeh ◽  
Abdolrasoul Rangrazi

Saliva contamination is a major clinical problem in restorative procedures. The purpose of this study was to evaluate the effect of the time of salivary contamination during light curing on the degree of conversion and the microhardness of a restorative composite resin. Eight groups of 10 samples for measuring the microhardness and eight groups of 5 samples for evaluating the degree of conversion were prepared. The samples of each group were contaminated with human saliva at a certain time. The first group (T0) was contaminated before light curing. The specimens in groups T2–T30 were contaminated at 2, 5, 10, 15, 20 and 30 s after the start of light curing, respectively. The samples of group T40 were contaminated after light curing. The degree of conversion and the microhardness of the specimens were measured by Fourier transform infrared (FTIR) spectroscopy and Vickers hardness testing techniques, respectively. The results of this study revealed that there were no significant differences between the groups in terms of the degree of conversion of the composite resin. Consistent with the findings for the degree of conversion, significant differences in the microhardness between the groups were not found. In conclusion, from a clinical point of view, the results of our study showed that the time of salivary contamination (before, during or after light curing of composite resin) has no significant effect on the polymerization (degree of conversion) and one of the important mechanical properties of dental composite resins (microhardness).

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1839 ◽  
Author(s):  
Bora Gwon ◽  
Eun-Bin Bae ◽  
Jin-Ju Lee ◽  
Won-Tak Cho ◽  
Hyun-Young Bae ◽  
...  

The aim of this study was to evaluate the wear properties of opposed dental ceramic restorative CAD/CAM materials and several posterior direct restorative composite resins. Three kinds of dental ceramics CAD/CAM materials (monolithic zirconia, lithium disilicate, leucite) and four dental composite resins—that is, MI Gracefil, Gradia Direct P, Estelite Σ Quick, and Filtek Supreme Ultra—were used in this study. For each of the 12 groups (three ceramics × four composite resins), five each of a canine-shaped ceramic specimen and a cuboidal shape opposing composite resin were prepared. All of the specimens were tested in a thermomechanical loading machine (50 N, 100,000 cycles, 5/55 °C). Wear losses of ceramic specimens and composite resin specimens were evaluated using a three-dimensional profiling system and an electronic scale, respectively. Statistical analyses were performed using the Kruskal–Wallis test and Mann–Whitney U test with Bonferroni’s correction. Zirconia showed significantly less volumetric loss than lithium disilicate or leucite regardless of composite resin type (p > 0.05/3 = 0.017), and that Estelite Σ Quick showed significantly more weight loss than Filtek Supreme Ultra, MI Gracefil, or Gradia Direct P regardless of ceramic type (p > 0.05/6 = 0.083). Zirconia showed less volumetric loss than lithium disilicate or leucite. Some composite resins opposing ceramics showed considerable weight loss.


2005 ◽  
Vol 288-289 ◽  
pp. 645-648
Author(s):  
Hwan Kim ◽  
Sung Ho Park ◽  
I.Y. Jung ◽  
S.B. Jeon ◽  
Kwon Yong Lee

In this study, the wear characteristics of five different dental composite resins cured by conventional halogen light and LED light sources were investigated. Five different dental composite resins of Surefil, Z100, Dyract AP, Fuji II LC and Compoglass were worn against a zirconia ceramic ball using a pin-on-disk type wear tester with 15 N contact force in a reciprocal sliding motion of sliding distance of 10 mm/cycle at 1Hz under the room temperature dry condition. The wear variations of dental composite resins were linearly increased as the number of cycles increased. It was observed that the wear resistances of these specimens were in the order of Dyract AP > Surefil > Compoglass > Z100 > Fuji ı LC. On the morphological observations by SEM, the large crack formation on the sliding track of Fuji ıLC specimen was the greatest among all resin composites. Dyract AP showed less wear with few surface damage. There is no significant difference in wear performance between conventional halogen light curing and light emitting diodes curing sources. It indicates that a light emitting diodes (LED) source can replace a halogen light source as curing unit for composite resin restorations.


2016 ◽  
Vol 10 (1) ◽  
pp. 446-453 ◽  
Author(s):  
Elisabeth Dursun ◽  
Hélène Fron-Chabouis ◽  
Jean-Pierre Attal ◽  
Anne Raskin

Background: Bisphenol A (BPA) is an endocrine disruptor with potential toxicity. Composite resins may not contain pure BPA, but its derivatives are widely used. Several studies found doses of BPA or its derivatives in saliva or urine of patients after composite resin placement. Objective: The aims of this study were to establish an exhaustive list of composite resins marketed in Europe and their composition, and to assess the extent of BPA derivatives used. Methods: A research on manufacturers' websites was performed to reference all composite resins marketed in Europe, then their composition was determined from both material safety data sheets and a standardized questionnaire sent to manufacturers. Manufacturers had to indicate whether their product contained the monomers listed, add other monomers if necessary, or indicate “not disclosed”. Results: 160 composite resins were identified from 31 manufacturers and 23 manufacturers (74.2%) responded to the survey. From the survey and websites, the composition of 130 composite resins (81.2%) was: 112 (86.2%) based on BPA derivatives, 97 (74.7%) on bis-GMA, 17 (13.1%) without monomer derived from BPA (UDMA, sometimes with TEGDMA) and 6 (4.6%) with UDMA (only); 1 (0.8%) did not contain a BPA derivative or UDMA or TEGDMA. Pure BPA was never reported. Conclusion: This work has established a list of 18 composite resins that contain no BPA derivative. Manufacturers should be required to report the exact composition of their products as it often remains unclear or incomplete.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Homan Naeimi Akbar ◽  
Keyvan Moharamzadeh ◽  
Duncan J. Wood ◽  
Richard Van Noort

The aim of the present study was to compare the translucency of different shades of two highly aesthetic multilayered restorative composite resins. In total nine shades from Esthet.X and ten shades from Filtek Supreme composite resins were chosen. Discs of each shade were prepared (N=3) and light-cured. Total and diffuse transmittance values for each sample were measured. Statistical analysis showed that the opaque dentine shades of both composites were the least translucent and the enamel shades had the highest translucency. There was a significant decrease in translucency from A2 to C2 of regular body shades and also from A4 to C4 of opaque dentine shades of Esthet.X composite resin. Grey enamel shade had a significantly higher diffuse translucency compared to clear and yellow enamel shades. There was a significant decrease in translucency from A2B to D2B and also in diffuse translucency from A4D to C6D shades of Filtek Supreme composite resin. It can be concluded that the color of the composite resins tested in this study had a significant effect on their translucency. Information on the translucency of different shades of composite resins can be very useful for the clinicians in achieving optimal esthetic restorative outcome.


2008 ◽  
Vol 27 (4) ◽  
pp. 523-533 ◽  
Author(s):  
Chang-Jun BAEK ◽  
Seok-Hee HYUN ◽  
Sang-Kyu LEE ◽  
Hyo-Joung SEOL ◽  
Hyung-II KIM ◽  
...  

2014 ◽  
Vol 8 (1) ◽  
pp. 144-147 ◽  
Author(s):  
Seyed Mostafa Mousavinasab ◽  
Mehrdad Barekatain ◽  
Elahe Sadeghi ◽  
Farzaneh Nourbakhshian ◽  
Amin Davoudi

Introduction:Hardness is one of the basic properties of dental materials, specially composite resins which is relevant to their polymerization. The aim of this study was to evaluate the effect of light curing distance and the color of clear Mylar strips on surface hardness of Silorane-based (SCR) and Methacrylate-based composite resins (MCR).Materials and methods:40 samples of MCRs (Filtek Z250) and SCRs (Filtek P90) were prepared in size of 5 mm×2 mm (80 samples in total). The samples divided into 8 groups (10 samples in each one) based on the color of clear Mylar strips (white or blue) and distance from light curing source (0 mm or 2 mm). All the samples cured for 40 second and stored in incubator for 24 hours in 37°C temperature. Surface hardness test was done by Vickers test machine and the collected data were analyzed by one-way ANOVA and paired T-test by using SPSS software version 13 at significant level of 0.05.Results:MCRs cured with blue Mylar strips from 0 mm distance had the highest (114.5 kg/mm2) and SCRs cured with white Mylar strips from 2 mm distance had the lowest (42.2 kg/mm2) mean of surface hardness. Also, the results of comparison among SCRs and MCRs showed significant differences among all groups (all P values <0.01).Conclusion:The hardness decreased as the distance increased and the blue Mylar strips provided higher hardness than clear ones. Also, Filtek Z250 showed higher hardness compared to Filtek P90.


2016 ◽  
Vol 10 (1) ◽  
pp. 538-545 ◽  
Author(s):  
Ayob Pahlevan ◽  
Masumeh Hasani Tabatabaei ◽  
Sakineh Arami ◽  
Sara Valizadeh

Objectives:Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights.Materials and Methods:DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were placed in Teflon molds and cured from the top. The thermocouple under samples recorded the temperature rise. After initial radiation and specimens reaching the ambient temperature, reirradiation was done and temperature was recorded again. Both temperature rise and DC data submitted to one-way ANOVA and Tukey-HSD tests (5% significance).Results:The obtained results revealed that DC was not significantly different between the understudy composite resins or curing units. Low shrinkage composite resin showed a significantly higher temperature rise than hybrid composite resin. Argon laser caused the lowest temperature rise among the curing units.Conclusion:Energy density of light curing units was correlated with the DC. Type of composite resin and light curing unit had a significant effect on temperature rise due to polymerization and curing unit, respectively.


2019 ◽  
Vol 8 (8) ◽  
Author(s):  
Luiz Henrique Soares Torres ◽  
Luiza Monzoli Covre ◽  
Caio Pimenteira Uchôa ◽  
Déborah Laurindo Pereira Santos ◽  
Renato Torres Augusto Neto ◽  
...  

As resinas compostas fotopolimerizáveis têm tido cada vez mais indicações na odontologia restauradora devido às vantagens que apresentam. Porém variações na técnica de fotoativação, densidade de energia, intensidade da luz e tempo de irradiação podem gerar polimerização incompleta, o que pode resultar em uma resina composta com alta porosidade, pouca dureza, baixo polimento, alta capacidade de pigmentação ou efeitos tóxicos na polpa. Este estudo tem por objetivo analisar o efeito do tempo de polimerização na pigmentação extrínseca de três resinas compostas fotopolimerizáveis. Utilizando uma fonte de LED, foram confeccionados 180 espécimes de resina composta microhíbrida, nanohíbrida e nanoparticulada, com diferentes protocolos de polimerização. Os espécimes foram subdivididos em grupos de acordo com o agente pigmentante. Com o uso de um colorímetro, foram analisados quanto à mudança de cor (ΔE). Os dados foram submetidos ao teste ANOVA e Duncan (α=0,05). A resina composta microhíbrida apresentou os menores valores de ΔE em comparação à nanoparticulada e à nanohíbrida quando imersos em vinho. Quanto maior o tempo de polimerização menores valores de ΔE foram obtidos. Não somente o tempo de polimerização influencia no grau de pigmentação, mas também fatores intrínsecos às resinas compostas tais como carga, agente fotoiniciador e matriz orgânica.Descritores: Autocura de Resinas Dentárias; Materiais Dentários; Pigmentação.ReferênciasMatson MR, Matson AMFP. Avaliação do grau de conversão de resinas compostas quando ativadas por luz halógena: método convencional, alta potência e método “soft”. Rev Inst Ciênc Saúde. 2006;24(4):307-11.Delaviz Y, Finer Y, Santerre JP. Biodegradation of resin composites and adhesivesby oral bacteria and saliva: A rationale for new material designs that consider the clinical environment and treatment challenges. Dent Mater. 2014;30(1):16-32.Nahsan FPS, Ueda JK, Silva JO, Schimitt VL, Naufel FS, Formighieri LA et al. Estabilidade de cor de resina composta após imersão em café, água e solução de clorexidina. Rev Bras Pesq Saúde. 2009;11(2):13-7.Al  Kheraif  AA,  Qasim  SS,  Ramakrishnaiah  R,  Rehman  I.  Effect  of different beverages on the color stability and degree of conversion of nano and microhybrid composites. Dent Mater J. 2013;(32)2:326-31.Ceballos L, Fuentes MV, Tafalla H, Martínez A, Flores J, Rodríguez J. Curing effectiveness of resin composites at different exposure times using LED and halogen units. Med Oral Pathol Oral Cir Bucal 2009;14(1):e51-6.Rahiotis C, Patsouri K, Silikas N, Kakaboura A. Curing efficiency of high- intensity light-emitting diode (LED) devices. J Oral Sci.  2010; 52(2):187-95.Sgarbi SC, Pereira SK, Martins JMH, Oliveira MAC, Mazur RF. Degree of conversion of resin composites light activated by halogen light and led analyzed by ultraviolet spectrometry. Rev Clín Pesq Odontol. 2010;6(3):223-30.Caldarelli PG, Beltrani FC, Santos FA, Shibayama R, Hoepper  MG. Manchamento de uma resina composta e sua Relação com o efeito da intensidade da luz Emitida por aparelhos fotopolimerizadores de Lâmpada halôgena. Rev Fac Odontol Aracatuba. 2011;(32)2:44-8.Valentini F, Oliveira SGD, Guimarães GZ, Barbosa RPS, Moraes RR. Effect of surface sealant on the color stability of composite resin restorations. Braz Dent J. 2011;22(5):365-68.Freitas ABDA, Gomes HR, Guimarães FBR, Marinho VA, Barros LM. Influência do tipo de aparelho fotopolimerizador na absorção de água por restaurações de resina composta. Rev Inst Ciênc Saúde.  2008;(26)1:65-9.Porto ICCM, Soares LES, Martin AA, Cavalli V, Liporoni PCS. Influence of the photoinitiator system and light photoactivation units on the degree of conversion  of  dental  composites. Braz Oral Res. 2010;24(4):475-81.Pequeno JHP, Araújo GS, Neri JR, Bomfim AGM, Mendonça JS, Santiago SL. Efeito dos protocolos de fotoativação na dureza de uma resina composta nanoparticulada. ROBRAC. 2012;21(56):394-97.Uhl A, Mills RW, Rzanny AE, Jandt KD. Time dependence of composite shrinkage using halogen and LED light curing. Dent Mater. 2005;21(3):278-86.Eick JD, Kotha SP, Chappelow CC, Kilway KV, Giese GJ, Glaros AG et al. Properties of  silorane-based  dental resins and composites containing    a    stressreducing  monomer. Dent Mater. 2007;23(8):1011-17.Neumann MG, Schmitt CC, Ferreira GC, Correa IC. The initiating radical yields and the efficiency of polymerization for various dental photoinitiators excited by different lightcuring units. Dent Mater. 2006;22(6):576-84.Asmussen   E,  Peutzfeldt   A.   Influence   of   composition   on   rate   of polymerization contraction of light-curing resin composites. Acta Odontol Scand. 2002;60(3):146-50.Silva EH, Albuquerque RC, Lanza LD, Vieira GC, Peixoto RT, Alvim HH et al. Influence of different light sources on the conversion of composite resins. Indian J Dent Res. 2011;22(6):790-94.Souza E, Espíndola M, Diegoli NM, Kuroshima KN. Avaliação da alteração de cor de diferentes compósitos restauradores - influência de corantes usados na cavidade oral - estudo in vitro. RGO. 2006;54(1):43-6.Salvego RN, Dias RPB. Figueiredo JLG. Estabilidade de cor de resinas compostas no processo de manchamento e clareamento, Rev Dental Press Estét. 2013;10(3):54-62.Firoozmandi LM, Balducci I, Araújo MAM.  Influência da Fotopolimerização e da Cor da Resina Composta na Microdureza. Pesq Bras Odontoped Clín Integr. 2009;9(1):37-42.Anfe TEA, Agra CM, Vieira GF. Comparação de duas técnicas de fotoativação na sorção e solubilidade de resinas compostas em solução de etanol. J Biodent Biomater. 2011;1(1):61-7.Villalta P, Lu H, Okte Z, Garcia-Godoy F, Powers JM. Effects of staining and bleaching on color change of dental composite resins. J Prosthet Dent. 2006;95(2):137-42.Barghi N, Berry T, Hatton C. Evaluation intensity output of curing lights in private dental offices. J. am. dent. assoc. 1994;125(7):992-96.Santini A, Miletic V, Swift MD, Bradley M. Degree of conversion and microhardness of TPO-containing resin-based composites cured by polywave and monowave LED units. J Dent. 2012;40(7):577-84.


2019 ◽  
Vol 56 (2) ◽  
pp. 434-439
Author(s):  
Cristina-Angela Ghiorghe ◽  
Vlad Carlescu ◽  
Claudiu Topoliceanu ◽  
Irina Nica ◽  
Galina Pancu ◽  
...  

The aim of this study was to evaluate the microhardness Rockwell and Young s modulus of a new nano-hybrid and nano-fill composite resins exposed to corrosive media. The study was performed on two composite resins, one nano-hybrid and one nano-fill, enamel, dentine, translucent, respectively body shade, of which were made 20 samples (25.0 � 0.1 mm lengths, 10.0 � 0.1 mm widths and 3.0 � 0.1 mm thicknesses), which were immersed in mouthwash for 1 minute per day for 10 days, the rest of the time being stored in artificial saliva. Measurements of Rockwell microhardness and Young�s modulus on samples were made between on the first day, after 6 days and 10 days of immersion in mouthwash comparative with 0 day. The results showed that after immersion in the corrosive environment, both materials had the hardness values changed, but medium values of Rockwell microhardness to nano-fill composite resin were higher than nano-hybride. At the nano-hybride composite resin, it was observed that the enamel and clear translucent groups had the mean values increased after the first day of exposure to mouthwash, compared to the dentine group, which showed a higher mean value after 6 days. At the nano-fill composite resin, for the enamel and body groups were obtained the higher values of HRC after 10 days. For the dentine group, after 6 days, Filtek Ultimate showed the same variation as Harmonize dentine shade. Harmonize composite resin showed higher values of Rockwell microhardness and Young�s modulus for all study groups compared to Filtek Ultimate.


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