scholarly journals Effect of Polymerization Time on Residual Monomer Release in Dental Composite: In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ezgi Sonkaya ◽  
Zeliha Gonca Bek Kürklü ◽  
Şeyhmus Bakır

Light activated resin-based composites are the most accepted and used materials among clinicians. The aim of this study is to determine the amount of residual monomer released from nanofiller composite resins for different polymerization times and storage periods in vitro. To this purpose, Tetric Ceram (Ivoclar, Liechtenstein), Clearfil Majesty Posterior (Kuraray, Japan), Grandio (VOCO, Germany), and Filtek Ultimate Universal (3M, USA) were used as nanofiller resin composites samples. Four groups ( n = 40 , diameter: 5 mm, thickness: 2 mm) of each material were fabricated, and each group was exposed to three different polymerization time (10, 20 and 40 sec). High-performance liquid chromatography (HPLC) was used to measure the amount of monomers released over 1, 15, and 30 days. The highest amount of monomer release was seen in Tetric EvoCream composite, while the least monomer release was seen in Clearfil Majesty composite. Regardless of the polymerization time, material, or storage period, the highest amount of eluted monomer was Bis-GMA. It is observed that there is no statistically significant difference between various polymerization times. Monomer release reached its highest level on the 15th day and decreased on the 30th day for all composites. Polymerization time did not affect the monomer release from the composites, but the type of the monomers and concentration of the filler used in the composites affected the amount of released monomers. The use of TEGDMA (co)monomer reduced the monomer release.

2019 ◽  
Vol 56 (3) ◽  
pp. 529-533
Author(s):  
Mihaela Pantea ◽  
Diana Andreea Ighigeanu ◽  
Alexandra Totan ◽  
Maria Greabu ◽  
Daniela Miricescu ◽  
...  

This in vitro study analyses the biochemical interaction between saliva and three types of dental composite resins (a direct resin, an indirect resin and a dual-cure resin used for cementation of indirect dental restorations). The resin samples were obtained following a specific protocol and in line with the producers� recommendations; the resin samples were incubated with saliva samples collected from 19 healthy volunteers. The obtained results showed that the tested composite resins did not produce significant changes in oxidative stress parameters that were analysed (albumin, uric acid, GGT / gamma glutamyl transferase, OXSR-1 / oxidative stress responsive kinase 1) and do not influence the inflammatory salivary status reflected by the levels of IL-6 - an inflammatory marker.


2016 ◽  
Vol 17 (12) ◽  
pp. 997-1002 ◽  
Author(s):  
Fahad I Alkhudhairy ◽  
Zeeshan H Ahmad

ABSTRACT Introduction Various bulk-fill materials depending on their composition, viscosity, and flow ability have different physical and mechanical properties. The aim of this in vitro study was to determine and compare the shear bond strength and microleakage properties of activa restorative with other bulk-fill restorative materials surefil (SDR), Biodentine, ever X posterior. Materials and methods Forty permanent premolars were selected for shear bond strength, and 20 permanent premolars were selected with class II cavities on mesial and distal side for microleakage. Universal testing device was used to assess the shear bond strength. Microleakage was checked using dye penetration method under a stereomicroscope. Mean and standard deviation values were calculated from the recorded values. Intergroup comparison was done by one-way analysis of variance (ANOVA) followed by pairwise comparison using Tukey honestly significant difference (HSD) post hoc test. Results The mean shear bond strength was highest for SDR surefil followed by Ever X posterior, Bioactive restorative, and Biodentine respectively. In this study, SDR (surefil) showed better shear bond strength and better microleakage properties compared with the other test materials (F = 186.7157, p < 0.05). Conclusion The result of this study showed that flowable and fiber-reinforced composites have better shear bond strength and microleakage properties. Clinical significance Flowable bulk-fill composite resins can be used as dentin substitutes because of its superior properties. How to cite this article Alkhudhairy FI, Ahmad ZH. Comparison of Shear Bond Strength and Microleakage of Various Bulk-fill Bioactive Dentin substitutes: An in vitro study. J Contemp Dent Pract 2016;17(12):997-1002.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4001
Author(s):  
Vincenzo D’Antò ◽  
Simone Muraglie ◽  
Beatrice Castellano ◽  
Ettore Candida ◽  
Maria Francesca Sfondrini ◽  
...  

Background: Attachments are composite auxiliaries that are used during a clear aligner orthodontic therapy to achieve difficult tooth movements. Two important factors are the planned configuration and the actual position of these auxiliary elements to obtain the desired force system. The aim of the present study was to evaluate the role of different composite materials in the correct reproduction of attachment shape and position. Methods: The materials that were considered in the study were a flowable resin, a dental restorative material, and an orthodontic composite. The attachments were created on three models of extracted teeth. Once the impressions were performed, 25 attachments of different shapes were added onto each virtual model to obtain the necessary templates to make the attachments. Each tested material was used to create a set of 25 attachments that were then scanned with an accuracy of 10μm. The resultant STL (stereolithography) files were superimposed onto the ones from the initial virtual plan, through Geomagic software, and the aligned scans were then compared while using a color map. The parameters that were calculated to make a comparison between the created attachments and the ideal ones were the maximum deviation in defect and in excess, the overflow, and the volume’s difference. In addition to these measurements comparing the three above-mentioned groups, the difference in volume between all the ideal and realized samples were analyzed. To test for differences among the three groups, a one-way Analysis of variance (ANOVA) was used with a Bonferroni post-hoc test. The level of significance was set at p < 0.05. Results: No statistically significant results were found between the three groups regarding the maximum value in defect, the maximum value in excess, and the minimum value as control, while a statistically significant difference was found between the overflow of orthodontic resin when compared to the flowable composite. Conclusions: The three materials that were used in this study were appropriate for attachment fabrication. The fidelity of attachment reproduction was similar when using the three different composites. The orthodontic composite showed more overflow when compared with the flowable one.


Author(s):  
Anjna Sharma ◽  
Pankaj Mishra

ABSTRACT Aim To compare the compressive strengths of composite resins and resin-modified glass ionomer cements (RMGICs) at different times. Materials and methods A total of 36 samples were prepared, 12 samples of each group, composite resins Filtek Z 250, Filtek Z 350, and resin-modified glass ionomer cement. Compressive strengths of specimens were measured after 1, 24 hours, and 7 days. Test was carried out on a “Universal Testing Machine” with cross-head speed of 5 mm/min. Results There was a significant difference between all the three restorative materials. Analysis of variance showed that mean compressive strengths of Z 250 after 1, 24 hours were higher than Z 350 and RMGIC (p < 0.05). The mean compressive strengths were reduced after 7 days in all the three groups, but after 7 days, the values of Z 250 when compared with the Z 350 and RMGIC were higher. Conclusion The study demonstrated that compressive strengths of hybrid composite resins (Z 250) were significantly higher than that of nanocomposites (Z 350) and RMGIC. How to cite this article Sharma A, Mishra P, Mishra SK. Time-dependent Variation in Compressive Strengths of Three Posterior Esthetic Restorative Materials: An in vitro Study. Int J Prosthodont Restor Dent 2016;6(3):63-65.


2019 ◽  
Vol 44 (3) ◽  
pp. E122-E132 ◽  
Author(s):  
L St-Pierre ◽  
C Martel ◽  
H Crépeau ◽  
MA Vargas

SUMMARY Objectives: The objective of this in vitro study was to compare, with a threshold value of 200 nm, the surface roughness obtained when using 12 different polishing systems on four different composite resins (microfill, nanofill, and two nanohybrids). Methods and Materials: A total of 384 convex specimens were made using Durafill VS, Filtek Supreme Ultra, Grandio SO, and Venus Pearl. After sandblasting and finishing with a medium-grit finishing disc, initial surface roughness was measured using a surface roughness tester. Specimens were polished using 12 different polishing systems: Astropol, HiLuster Plus, D♦Fine, Diacomp, ET Illustra, Sof-Lex Wheels, Sof-Lex XT discs, Super-Snap, Enhance/Pogo, Optrapol, OneGloss and ComposiPro Brush (n=8). The final surface roughness was measured, and data were analyzed using two-way analysis of variance. Pairwise comparisons were made using protected Fisher least significant difference. Results: There were statistical differences in the final surface roughness between polishing systems and between composite resins (p&lt;0.05). The highest surface roughness was observed for all composite resins polished with OneGloss and ComposiPro Brush. Enhance/Pogo and Sof-Lex Wheels produced a mean surface roughness greater than the 200-nm threshold on Filtek Supreme Ultra, Grandio SO, and Venus Pearl. Data showed that there was an interaction between the composite resins and the polishing systems. Conclusions: A single polishing system does not perform equally with all composite resins. Except for Optrapol, multi-step polishing systems performed generally better than one-step systems. Excluding Enhance/Pogo, diamond-impregnated polishers led to lower surface roughness. Durafill VS, a microfill composite resin, may be polished more predictably with different polishers.


Author(s):  
Fábio Nakao ARASHIRO ◽  
Michelle Tavares Galotto NANTES ◽  
Pedro Gregol da SILVA ◽  
Key Fabiano Souza PEREIRA ◽  
Muryllo Eduardo Sales dos SANTOS

ABSTRACT Objective: This research study aims at conducting an in vitro evaluation of crack formation in freshly extracted teeth after undergoing different storage and decontamination methods. Methods: 60 erupted upper third molars conventionally extracted using forceps # 210h (quinelato surgical instruments, rio claro - sp) and randomly distributed in three groups (n = 30): group 1 - storage in dry environment for 30 days, group 2 - sterilization in autoclave and storage for 30 days in distilled water, and group 3 - 10% formaldehyde decontamination for 14 days and storage in distilled water for additional 30 days. after the storage period, teeth had their roots transversely sectioned at 2, 4 and 6 mm below the root apex using a low rotation diamond disk under constant cooling. the evaluation of fragments was performed using a 30-time magnification microscope. Results: Cracks were seen only in group 1 and the chi-square statistical test with 5% significance level showed a statistically significant difference comparing the dry storage group to the others. Conclusion: The storage of extracted teeth in a dry environment influences the formation of dentinal defects.


Author(s):  
Magrur Kazak DDS, PhD ◽  
Nazmiye Donmez DDS, PhD ◽  
Fatemeh Bahadori PhD ◽  
Vildan Betul Yenigun PhD ◽  
Abdurrahim Kocyigit MD, PhD

Objective: Studies have focused on use of non-expired composites. Unfortunately some clinicians still use expired composite resins without considering their effects. The objective of this in vitro preliminary research was to investigate cytotoxicity of expired(6-months) and non-expired composite resins. Materials and methods: Expired (E) and non-expired (NE) samples of one bulk-fill (Tetric N-Ceram Bulk-fill [TNB], Ivoclar Vivadent), two nano-hybrid (Tetric N-Ceram [TN], Ivoclar Vivadent; Clearfil Majesty ES-2 [CM], Kuraray) composite resins were tested on L929 fibroblast cells. Medium covering cells was removed then plastic rings (2-mm height) were filled with non-polymerized composite resins, placed in direct contact with cells and polymerized with LED light curing unit (LCU). Three samples were prepared for each group. After polymerization, removed medium was added to the cells. Cells that were left without medium (WOM) and cells that were exposed to LCU were used as positive control groups. Cells without any treatment were used as negative control group (C). Cells were incubated with tested materials for 7-days to evaluate cytotoxicity. Cell viability was calculated by sulforhodamine B test as a percentage (%). One-way ANOVA and post-hoc Tukey tests were used for statistical analyses (p<0.05). Results: Comparison between E and NE groups of same composite resins did not result in statistically significant differences (p>0.05), except between TN NE and TN E (p<0.05). TN E group was significantly more cytotoxic than TN NE group. When NE composite resin groups were compared to each other, statistically significant difference was only obtained between TNB NE and TN NE (p<0.05). Among all tested groups, TN NE group showed the least cytotoxic profile. No statistically significant differences were determined when E composite resin groups were compared to each other (p>0.05). All experimental groups compared with C group showed statistically significant cytotoxicity (p<0.05). A statistically significant difference existed between LCU and C groups (p<0.05). Conclusions: In clinical practice, expired composite resins should never be used. Although a correlation was found between expiration dates of nano-hybrid composite resins and cell viability, opposite data were obtained for bulk-fill composite resin. Researches are still required to evaluate biocompatibility of bulk-fill composite resins at various thicknesses with current LCUs.


2012 ◽  
Vol 10 (2) ◽  
pp. 98-104
Author(s):  
P Mazumdar ◽  
U Kumar Das ◽  
R Kundu

Introduction: Composite resins have become one of the most commonly used direct restorative materials for anterior and posterior teeth.Objectives: To observe and analyze the gap at the resin dentin interface in class II cavities restored with light cure composite resin in four experimental groups employing 37% phosphoric acid or self etching monomers and restored with /without light cure flowable composite resin.Methods: 40 sound maxillary first premolars, extracted due to orthodontic reasons was taken, distoproximal cavities were prepared and divided into 4 groups. Teeth of Group 1 was etched by 37% Phosphoric acid and light cure flowable composite resin was used, in group 2 ,two coats of self etching acidic monomer were applied and light cure flowable composite resin was used. Teeth of group 3 was etched with 37% phosphoric acid and restored without light cure flowable composite resin and in group 4, two coats of self etching acidic monomer were applied and restored without using light cure flowable composite resin material. Thermocycling was done after finishing and polishing and viewed under scanning electron microscope to observe and analyze the gap between tooth and the restoration.Result: Gap was observed at dentin-composite resin interface in all 4 groups. Results were evaluated by F-test and Manwhitney U test. No statistically significant difference was found.Conclusion: Use of flowable composite resin liner and the etching technique do not have any influence on the gap.DOI: http://dx.doi.org/10.3126/hren.v10i2.6571 Health Renaissance 2012; Vol 10 (No.2); 98-104


2021 ◽  
Vol 10 (4) ◽  
pp. e27310414305
Author(s):  
Ricardo Coelho Okida ◽  
Isis Almela Endo Hoshino ◽  
Lívia Patrícia Romanini ◽  
Amanda Maslen Fontes ◽  
Lara Maria Bueno Esteves ◽  
...  

The aim of this study was to evaluate the influence of the polishing period on surface roughness (Ra) before and after thermal aging in four composite resins - CR (Durafill VS, Vittra APS, Filtek Z350XT and Spectra Smart). This in vitro study evaluated: (1) CR in 4 levels; (2) polishing period (PP) in three levels (immediate, 7 and 14 days) and (3) artificial aging in two levels: without aging and after 10,000 cycles. For this, 240 CR specimens were allocated into 12 groups (n=20) according to PP with SofLex Pop On disks.  For Ra, 3 measurements on the top surface of each specimen were performed with a diamond tip and constant load of 4mN and 0.25mm/s. Next, the specimens were aged in thermocycling, with temperatures of 5° and 55°C, during 30 seconds in each temperature, and repeated testing afterwards. The data were submitted to statistical tests with 5% significance. The alteration in Ra was observed only in the late polishing in the period of 7 days, where the Durafill VS CR showed higher Ra in comparison to the other CRs. After thermocycling, the groups showed significant difference only with late polishing in the 21-day period; the nanoparticulated RCs (Z350XT˂Vittra APS) recorded the highest Ra values, followed by the microhybrid (DurafillVS) and nanohybrid (Spectra Smart) RCs, respectively. Thus, late polishing in the 7-day and immediate period provided higher Ra values, especially for the nanohybrid and microhybrid composite resins.


2018 ◽  
Vol 7 (2) ◽  
pp. 28-31
Author(s):  
Varunjeet Chaudhary ◽  
Sanad Singh Solanki ◽  
Varsha Yadav ◽  
Seema Lahoti

Objective: To evaluate the shear bond strength of stainless steel brackets bonded with fluoride-releasing composite resins, comparing effect of adhesion booster and conventional primer.Materials & Method: Sixty extracted premolars were subjected to bracket bonding with fluoride-releasing composite resin; which were bonded by randomly divided into two groups of bonding agents: Group 1- conventional primer as control group, Group 2- adhesion booster. After bonding, the samples were thermocycled (500 cycles) at 5ºC and 55ºC temperatures. After 48 hours they were subjected to shear bond strength testing in occluso-gingival direction, using an MTS 810 Universal Testing Machine with load speed of 0.5 mm/min.Result: Mean shear bond strength was significantly more in samples bonded with adhesion booster (14.792±3.805 Mpa) as compared to conventional primers (11.327±4.047 Mpa). There was statistically significant difference in shear bond strength between the groups (p=0.001).Conclusion: The use of the adhesion booster significantly increased the bond strength of bracket bonded with fluoride-releasing composite.


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