Surface Hardness Of Composite Resin Research Articles

Influence of the Loading with Newly Green Silver Nanoparticles Synthesized Using Equisetum sylvaticum on the Antibacterial Activity and Surface Hardness of a Composite Resin.

The aim of the study was to evaluate the antibacterial activity and surface hardness of a light-activated microhybrid composite resin modified with green silver nanoparticles (AgNPs). AgNPs were synthesized using an Equisetum sylvaticum extract and characterized through different methods such as UV-Vis, EDX, and FTIR. The obtained AgNPs were mixed with a microhybrid composite resin (Herculite XRV, Kerr Corp., Orange, CA, USA) in different concentrations: 0% (group A-control); 0.5% (group B); 1% (group C); and 1.5% (group D). A total of 120 composite resin disk-shaped samples were obtained and divided into 4 groups (n = 30) according to AgNP concentration. Each group was then divided into 2 subgroups: subgroup 1-samples were not soaked in 0.01 M NaOH solution; and subgroup 2-samples were soaked in 0.01 M NaOH solution. The antibacterial activity against Streptococcus mutans was determined using a direct contact test. A digital electronic hardness tester was used to determine the composite resin's Vickers surface hardness (VH). Statistical analysis was performed using the Mann-Whitney U and Kruskal-Wallis nonparametric tests with a confidence level of 95%. Groups C and D showed higher antibacterial activity against S. mutans when compared to the control group (p < 0.05). No significant differences were recorded between VH values (p > 0.05). The use of AgNPs synthesized from Equisetum sylvaticum as a composite resin filler in 1% wt. and 1.5% wt. reduced the activity of Streptococcus mutans. Soaking of the experimental composite resin decreased the antibacterial efficacy. The loading of a microhybrid composite resin with AgNPs in concentrations of 0.5% wt., 1% wt., and 1.5% wt. did not influence the surface hardness.

Benefit of Glycerine on Surface Hardness of Hybrid &amp; Nanofill Resin Composite

Background: Composite resins restoration is a treatment for tooth structure loss due to pathological conditions. Longevity of composite resins restoration can be affected by surface hardness restoration. Glycerin can increase surface hardness restoration with inhibit bond oxygen and free radicals on polymerization composite resins. Purpose: Analyze the increase surface hardness composite resins restoration after glycerin application before light-curing composite resins. Review(s): Of the six journals included in this literature review, five journals reported significant differences because of the obstacles in the polymerization process of the composite resin when composite contact with light-curing will activate the photoinitiator to produce highly reactive free radicals, free radicals will break the double chain carbon bonds of monomers and form single bonds of free radicals with monomers. Bonding of free radicals with monomers will produce polymeric bonds (degree of conversion) which affects the level of surface hardness of the filling. While one journal noted no significant difference in the surface hardness of composite resin after glycerin application. Conclusion: The use of glycerin before light-curing can increase the surface hardness composite resin restorations.

Comparison Of The Effect Of Acid Type Of Cuko Pempek On The Surface Hardness Of Mycrohybrid And Nanohybrid Composite Resin

Abstract often used nowadays because of the combination of filler with good aesthetic and mechanical strength. Various factors in the oral cavity such as acid solution can affect the surface hardness of composite resin. Cuko pempek is an additional sauce that served which has acidic pH. This study aimed to compare the effect of acid type of cuko pempekhardness of microhybrid and nanohybrid composite. Materials and Methods:Thirty-six samples of microhybrid (n=18) and nanohybrid composite (n=18) with 5 mm in diameter and 2 mm in thickness were immersed in three different solutions: artificial saliva (control), cuko pempek using vinegar, and cuko pempekSurface hardness was measured before and after immersion using Vickers Hardness Tester. Resultsshowed a significant difference on the surface hardness of composite resin before and after ardness of microhybrid and nanohybrid composites after (p&lt;0,0167) showed statistically significant differences, while there were no cuko pempek using vinegar and tamarind (p&gt;0,0167). This study alsothat there were significant differences on the surface hardness of microhybrid and nanohybrid composite after cuko pempek using vinegar, and cuko pempek using tamarind (p&lt;0,05). face hardness of nanohybrid composite was lower than microhybrid composite after using vinegar and tamarind. composite resin, surface hardness. 

PERENDAMAN DENGAN PERASAN BUAH JERUK LEMON (Citrus lemon) DAPAT MENURUNKAN KEKERASAN RESIN KOMPOSIT NANOHYBRID

Composite resin is a restoration material that is often used because the composite resin has good aesthetic value like mimetic the teeth color. Composite resins have a physical and mechanical condition. One of the mechanical condition is hardness. The surface hardness of composite resins is the surface resistance of the composite resin material to the applied pressure. One of the factors influencing composite hardness is the food and beverages consumed. Consuming acidic drinks continuously for a long time period can erode composite resin filling. The purpose of this study was to determine the effect of soaking into a citrus lemon on the hardness of nanohybrid composite resin. This type of research was true experimental with pre-test post-test with control group design using 24 composite resin samples which are divided into 4 groups with 6 samples each. The groups in this study were nanohybrid composite resins soaked with citrus lemon and aqua dest for 60 minutes and 120 minutes. The hardness tested using a Vicker hardness tester. The results of the study using the LSD (Least Significant Difference) test showed that the significance value of p= 0.014 (p&lt;0.05), which means that the use of citrus lemon for 120 minutes affected the hardness of nanohybrid composite resin. In conclusion, soaking with citrus lemon for 120 minutes reduces more the hardness of nanohybrid composite resin compared with soaking for 60 minutes.

Effect of Bench Time on Surface Hardness of Nanofiller Composite Resin

The purpose of this study was to evaluate the effect of different bench time on surface hardness of the composite resin after being stored in the refrigerator at 4°C. Before used in this study, the composite resin was refrigerated at 4°C for the test group and kept at 25°C for the control group. The specimens were divided into control group (I) and five experimental groups according to the bench time before polymerization, 0 (II); 15 (III); 30 (IV); 45(V); and 60 (VI) minutes. Sixty specimens with 10 mm diameter and 2 mm thickness were made by using nanofiller composite resin. The material was filled into stainless steel mold and curing for 20 s. After kept in a dark box for 24 hours, the surface hardness of all specimens were tested using Microhardness Tester. The data were analyzed with one-way ANOVA (p≤0.05) and LSD’s post hoct test. The results showed that the 60 minute bench time group presented the highest surface hardness value followed by 45, 30, 15 and 0 minutes bench time group. Moreover, the hardness value of 60 min group was almost similar with the control group. Statistical analysis showed no significant differences (p>0.05) between groups. It concluded, bench time has an effect on the surface hardness of composite resin but no significant differences statistically.

The evaluation of the surface micro-hardness values in different depth of resin blocks

Objective: Computer-aided design and manufacturing technology has shown great improvement in dentistry since the 1980s. This technology is based on a one-stage restoration using prefabricated blocks. Two main types of materials are used during CAD / CAM indirect restorations:  glass-ceramic / ceramic and resin composite. CAD / CAM resin blocks are polymerized under high temperature and pressure. Polymerization depth affects the surface hardness of composite resins. When preparing a restoration, different depth layers of the resin block are used. The aim of this study is to show that adequate polymerization is achieved in each layer of the resin blocks and that the hardness of each layer is the same. Two composite resin block materials and one hybrid resin block material were included in this study. Material and method: The CAD/CAM block materials evaluated in this study were Cerasmart, Lava  and Vita Enamic Square specimens (n=5/material) of approximate dimensions 10×10×2 mm blocks were sectioned (5 slices/block) from commercially available CAD-CAM materials using a diamond saw (exakt 300 cl Apparatebau, Norderstedt, Germany) with water cooling. All specimens were abraded followed by 500,1200,2500 grid using SiC abrasive paper (exakt 400 cs Apparatebau, , Norderstedt, Germany). After storage in distilled water at 37 °C for 24 hours the Knoop hardness test was performed using a hardness testing machine (Buehler MMT 3 digital micro hardness tester, Lake Bluff, IL, USA) using a load of 500 gf and a loading time of 10s. Results: The material with the highest hardness number was Vita Enamic block, whereas the lowest numbered group was the Cerasmart. The rank order of surface hardness was as follows: Vita Enamic&amp;gt; Lava Ultimate &amp;gt;Cerasmart. Conclusion: The hardness measurements of the layers of blocks were similar.

THE EFFECT OF THERMOCYCLING TEST ON THE SURFACE HARDNESS VALUE OF BULK FILL RESIN COMPOSITE

Background: Bulk fill typed composite resin can be applied at once into the tooth cavity of approximately 4 mm. The surface hardness of composite resin can be affected by temperature. Variation temperature in oral cavity due to the consumption of cold and hot food or beverages. Thermocycling tests are used to simulate aging of restorative materials in oral cavity by exposing material to repeated cycles of cold(4 oC) and hot(60°C) temperatures. Purpose: To analyze thermocycling test effect with 1500 and 3000 cycles to the surface hardness value bulk fill composite resin. Methods: This study is true experimental post test only with control group design. This study used 27 samples of bulk fill composite resin divided into 3 groups, first group is control group that did not do thermocycling test, second group is group of thermocycling 1500 cycles and third group of thermocycling 3000 cycles. Results: Mean value of composite resin surface hardness control group 46.529 ± 1.331 MPa, group thermocycling 1500 cycles 44.100 ± 1.039 MPa, and group thermocycling 3000 cycles 42.251 ± 1.470 MPa. The data were tested using One Way ANOVA and post Hoc Bonferroni with p <0.05, there were significant differences in all treatment group. Conclusion: Thermocycling test with 1500 and 3000 cycles (equal with clinically used 6 month and 1 year) in resin composites may decrease surface hardness value

THE EFFECT OF THERMOCYCLING TEST ON THE SURFACE HARDNESS VALUE OF BULK FILL RESIN COMPOSITE

Background: Bulk fill typed composite resin can be applied at once into the tooth cavity of approximately 4 mm. The surface hardness of composite resin can be affected by temperature. Variation temperature in oral cavity due to the consumption of cold and hot food or beverages. Thermocycling tests are used to simulate aging of restorative materials in oral cavity by exposing material to repeated cycles of cold(4 oC) and hot(60°C) temperatures. Purpose: To analyze thermocycling test effect with 1500 and 3000 cycles to the surface hardness value bulk fill composite resin. Methods: This study is true experimental post test only with control group design. This study used 27 samples of bulk fill composite resin divided into 3 groups, first group is control group that did not do thermocycling test, second group is group of thermocycling 1500 cycles and third group of thermocycling 3000 cycles. Results: Mean value of composite resin surface hardness control group 46.529 ± 1.331 MPa, group thermocycling 1500 cycles 44.100 ± 1.039 MPa, and group thermocycling 3000 cycles 42.251 ± 1.470 MPa. The data were tested using One Way ANOVA and post Hoc Bonferroni with p <0.05, there were significant differences in all treatment group. Conclusion: Thermocycling test with 1500 and 3000 cycles (equal with clinically used 6 month and 1 year) in resin composites may decrease surface hardness value

PENGARUH JUS JERUK DAN MINUMAN BERKARBONASI TERHADAP KEKERASAN PERMUKAAN RESIN KOMPOSIT

Background: Orange juice and Carbonat drink contains an acid agent which can affect the surface hardness of composite resin. Changes of surface hardness of composite resin is caused by infiltration of water containing the acid agent that affect the bonding of matrix to filler composite resin. This study purpose to determine the effect of immersed orange juice and carbonat drink on surface hardness of composite resin. Method: This was experimental laboratory study with a pre and post test control group design. The samples of composite resin had 12 mm in diameters and 2 mm in thickness (n=27). Composite resin used is FiltexTM Z350 XT shades A2. Samples were divided into three groups : group A immersed with orange juice, group B immersed with carbonat drink, and group C immersed with aquadest as the negative control. Samples were immersed for 24 hours. The pre and post immertion of composite resin surface hardness were measured with Micro Vickers Hardness Tester. Results: Post immertion Vickers hardness was compared by using one way anova test. The result showed that immersed orange juice and carbonat drink significantly reduced the surface hardness of composite resin (p &lt; 0,05). Concluision: The conclusion Immersed carbonat drink more reduced the surface hardness of composite than orange juice. It is suggested to reduce the duration direct exprossure of consumption carbonat drink.

Surface Hardness of Dental Composite Resin Restorations in Response to Preventive Agents

To assess the impact of using preventive mouthwash agents on the surface hardness of various resins composites. Hundred specimens were prepared from five types of composite resin material in a Teflon mold. Five specimens from each type of restorative materials (Herculite XRV Ultra, Estelite Σ Quick, Z Hermack, Versa Comp Sultan, and Empress Direct IPS) were evaluated posttreatment with immersion in four types of preventive mouthwashes gels and rinses - group 1: Flocare gel (0.4% stannous fluoride), group 2: Pascal gel (topical APF fluoride), group 3: Pro-relief mouthwash (Na fluoride), and group 4: Plax Soin mouthwash (Na fluoride) - at 37°C in a dark glass container at 24, 48, and 72 hours. Surface hardness measurement was made for each tested material. Statistically, we analyzed the mean values with one-way analysis of variance (ANOVA) and Tukey's test, with significance level of p < 0.05. All composite resin materials showed decrease in their surface hardness with the time elapsed (24, 48, and 72 hours) postimmersion in the preventive mouthwashes and gels except the Herculite XRV Ultra and Versa Comp Sultan materials. Flocare gel group showed increase in the surface hardness after 48 hours of immersion than the other periods and in Estelite Σ Quick after 72 hours. There was significant differences in all materials tested with the immersion in the preventive mouthwashes and gels, such as Flocare gel (0.4% stannous fluoride), Pro-relief mouthwash (Na fluoride), and Plax Soin mouthwash (Na fluoride) except Pascal gel (topical APF fluoride) (p > 0.05), at time intervals mentioned earlier (p < 0.05). The effect of preventive mouthwashes and gels on resin composite materials was decreased surface hardness with the time elapse of immersion for all materials except the Flocare gel group, which contains 0.4% stannous fluoride as a preventive ingredient increases the surface hardness after 48 h for Herculite XRV Ultra and Versa Comp Sultan and Estelite Σ Quick after 72 hours. The preventive agents in the form of mouthwash and gel are used to prevent oral diseases that affect the surface hardness of composite resin, and this leads to occlusion, color stability, and surface roughness.

새로운 광증감제 사용에 따른 UDMA 복합수지의 특성

Purpose: The purpose of this study was to know the availability of two photosensitizers, PD, DA, as a photosensitizer instead of CQ in UDMA dental composite resin. We want to know photopolymerization effect of UDMA unfilled resin and surface hardness of composite resin containing PD and DA were compared with those of CQ, most widely used photosensitizer for dental composite resins. Methods: The photopolymerization effect of UDMA studied by FT-IR spectroscopy increased with irradiation time and the amount of photosensitizer. Knoop hardness of experimental composite resins prepared by the addition of the photosensitizer content and irradiation time. Results: The relative photopolymerization effect of UDMA increased in the order of PD > CQ > DA. The composite resin of UDMA containing DA or PD, which shows better Knoop hardness than that containing CQ. Conclusion: PD and DA show as effective photosensizers, suitable for UDMA dental composite resin compare with a higher efficiency than CQ.

Influence of two methods of additional activation on composite resins surface hardness

Aim: To evaluate the influence of two methods of additional activation on the surface hardness of composite resins. Methods: Two types of composites were tested: Filtek P60 and Filtek P350. For each material, 48 specimens were prepared and divided into four groups: Group 1 (control) - conventional activation, using a halogen light for 40 s; Group 2 - conventional activation and additional activation with a halogen lamp for 60 s; Group 3 - conventional activation and additional activation with an autoclave at 127°C for 6 min at 1.7 kg/cm3 pressure; and Group 4 - conventional activation and additional activation with an autoclave at 134 °C for 15 min at 2.1 kg /cm3 pressure. The use of autoclave has been suggested for being a standard equipment at dental offices, and thus, even at locations far from dental laboratories, it would be possible to have simple techniques that allow access to indirect restorations at lower costs. Data obtained in the study were analyzed statistically by analysis of variance followed by Tukey’s test at a 5% level of significance. Results: For Z350, there was a significant increase in hardness for all groups of additional activation (Groups 2, 3 and 4), compared with the control group. For P60, a significant increase in surface hardness was found compared with the control group for the groups that used additional activation with an autoclave (Groups 3 and 4). Conclusions: Additional activation with an autoclave increased the surface hardness of the tested resins to a greater degree than additional activation with a halogen light.

The effect of colored drinks on the surface hardness of composite resin.

Aims: to determine the effect of colored drinks on the surface hardness of three types of composite restorations. Materials & methods: Three composite resins (a compoglass, conventional and ceramic composites) were used in this study. Transparent disc with 2mm thickness and hole of 5mm diameter were used for the preparation of composite samples, ten samples were made for each type of composite with a total of 30 samples. Four samples from each type of composite were immersed in( a cola ,tea, normal saline and coffee) respectively (normal saline as a control for the study),after that each colored drink measure amount of ph before put the samples using ph meter(Pw 9421,philips) and then each sample stored for (one week, two week and one month) inside incubator at 37° C then the samples were tested for the micro hardness with a Vickers micro hardness tester(Wolpert,Germany)with 200g load. Five micro hardness measurements were obtained on top surface of each sample on the following time period: before immersing in color drinks, after immersing each samples in cola, coffee and tea. Data were analyzed using One way analysis (ANOVA) and Duncan, a value of P≤ 0.05 was consi-dered significant .Results: The results of ANOVA showing a significant difference among all ceram-ic samples regarding all media and time when P≤ 0.05.Conclusion: it can be concluded that all conven-tional materials are susceptible to the effect of aqueous media of oral cavity and other softening drink.

Effect of Inhomogeneity of Light from Light Curing Units on the Surface Hardness of Composite Resin

This study investigated the characteristics of output light from different types of light curing units, and their effects on polymerization of light-activated composite resin. Three quartz-tungsten-halogen lamps, one plasma arc lamp, and one LED light curing unit were used. Intensity distribution of light emitted from the light guide tip was measured at 1.0-mm intervals across the guide tip. Distribution of Knoop hardness number on the surface of resin irradiated with the light curing units was also measured. For all units, inhomogeneous distribution of light intensity across the guide tip was observed. Minimum light intensity values were 19-80% of the maximum values. In terms of surface hardness, inhomogeneous distribution was also observed for the materials irradiated with the tested units. Minimum values were 53-92% of the maximum values. Our results indicated that markedly inhomogeneous light emitted from light curing unit could result in inhomogeneous polymerization in some areas of the restoration below the light guide tip.

Evaluation of the surface hardness of composite resins before and after polishing at different times

Purpose:The aim of this study was to evaluate the surface hardness of six composite resins: Revolution, Natural Flow, Fill Magic Flow, Flow-it! (flowables), Silux Plus (microfilled) and Z100 (minifilled) before and after polishing at different times.Materials and Methods:For this purpose, 240 specimens (5mm diameter, 1.4mm high) were prepared. Vickers hardness was determined before and after polishing at different times: immediately, 24h, 7 and 21 days after preparation of the samples. Statistical analysis was performed by ANOVA and Tukey test.Results:There was no difference in the hardness of flowable resins, which had lower hardness than the minifilled resin. The minifilled resin showed the highest surface hardness as compared to the other materials (p<0.01). All materials exhibited higher hardness after polishing, being more evident after 7 days.Conclusion:It may be concluded that, regardless of the composite resin, surface hardness was considerably increased when polishing was delayed and performed 1 week after preparation of the samples.