Evaluation of Compressive Strength of Repaired Direct Composite Resin Restorations

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The aim of the study was to evaluate the influence of different techniques of finishing and polishing as well as the use of sealants on the surface condition of some composite resins used in the dental office. 80 specimens of composite materials (Nanoceramic, Nanocomposit and Nanohybrid) were made and divided into 3 groups G1-coated composite with sealant lacquer, G2 - finished in 2 stages, and G3 - finished in 3 stages. Roughness (Ra) was determined with the Taylor Hobson Form Talysurf Profiometer. The data was analyzed using one-way ANOVA followed by a multiple comparison t test. Significant differences were found between the groups in terms roughness (p [ 0.001). The results showed that Seal - and - Shine (PULPDENT) was capable of reducing surface roughness and provided polished surfaces for all materials.

Section: Tabel 1 Materials Used In the Studymentioning

confidence: 49%

Comparative Evaluation of the Effect of Surface Polishing of a Glaze/composite Sealant and Different Polishing Systems on Surface Roughness of Three Composite Resin Type

Bolat¹,

Stoleriu²,

Iovan³

et al. 2018

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“…Stress applied to the surface of the material in a dry environment is transmitted inside the structure through the silane layer and causes deformation both inside and outside the nanoclusters. The presence of water in the resin matrix could diminish the internal concentration of the wiping and would allow the cracks to spread [25][26][27][28]. Moreover, when wet materials are tested, hydrolysis and polymerization of the silane phase inside the nanoclusters causes changes in stress transmission both inside and outside the nanoclusters.…”

Section: Sem Evaluation Of Fractured Surfacesmentioning

confidence: 99%

Comparative Study Regarding the Compressive Strength of Different Composite Resins Used for Direct Restorations

Nica¹,

Iovan²,

Stoleriu³

et al. 2018

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The aim of this study was to evaluate and to compare the compression behavior under identical mechanical tests, of three different composite resins, by determining Young�s modulus for compression, ultimate compressive strength and ultimate compressive strain. The studied materials were: Filtek Z250 Universal Restorative, Filtek Z550 and Filtek Bulk Fill Posterior Restorative (3M ESPE, St. Paul, MN, USA). Fifteen cylindrical samples, having 6 mm in height and 5 mm in diameter, were made from each material, using plastic molds. The samples were subjected to quantitative analysis of the compression behavior after mechanical tests. The fractured fragments of the samples were subjected to qualitative surface evaluation by scanning electron microscopy. Results were statistically analyzed using one-way analysis of variance (ANOVA) with Tukey�s post hoc test. Filtek Z250 had the lowest value of Young�s modulus for compression and the results were statistically significant (p[0.05) when compared to Filtek Bulk Fill Posterior Restorative and Filtek Z550. There were no statistically significant differences between all three materials regarding ultimate compressive strength (p]0.05). The lowest value for ultimate compressive strain was recorded for Filtek Bulk Fill.

“…The evaluation of warmed restorative materials mechanical properties is essential to determine the effect of heat on material capability to resist to occlusal forces, fracture and wear. Surface hardness, compressive strength [22], and diametral tensile strength are common investigations to establish the mechanical behavior of restorative materials in oral cavity [23][24][25].…”

mentioning

confidence: 99%

The Effect of Heating on Surface Microhardness of Resin-based Materials for Direct Restoration

Stoleriu¹,

Iovan²,

Nica³

et al. 2018

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The aim of this study was to evaluate and to compare the surface hardness of three types of resin-based materials used for direct restoration after heating at different temperatures. A giomer (Beautifil II, Shofu Dental), a compomer (Dyract eXtra, Dentsply Sirona) and a hybrid composite resin (Gaenial Posterior, GC Corporation) were selected for this study. Twenty disk-shaped specimens of each material were heated at room temperature (21�C), at 37�C, at 50�C and at 60�C. Vickers microhardness test was performed on top and bottom surfaces using digital microhardness tester (Micro-Vickers Hardness System CV- 400DMTM, CV Instruments Namicon). The top and bottom surfaces VHN was calculated as a mean value of five determinations. Also, the microhardness ratio was calculated by dividing the top mean VHN value by bottom mean VHN value. Increased mean hardness values were recorded after heating, irrespective of resin-based tested materials. The highest hardness values were recorded after heating all three materials at 60�C, followed by the hardness recorded at 50�C, 37�C and 21�C. For top surfaces, the lowest hardness value was recorded in Dyract eXtra group when samples were warmed at room temperature and the highest hardness value was obtained in Beautifil II group when samples where heated at 60�C. For the bottom surfaces, Dyract eXtra specimens heated at 21�C presented the lowest hardness values and Beautifil II samples heated at 60�C presented the highest hardness values. On top and on bottom surfaces Dyract eXtra showed the lowest hardness values, followed by G-aenial Posterior and Beautifil II, irrespective the heating temperature.