The effect of glycerin on the surface hardness and roughness of nanofill composite

Abstract

Background: Present research studied the surface hardness and roughness dependence on polymerization. Polymerization of composites occurs through chain reaction that is induced by free radicals. Oxygen in the air decreases the excitability of the photo initiator, causing polymerization interference. Oxygen inhibition layer (OIL) is formed on the surface. OIL can be reduced by curing the composite through by application of glycerin to the surface. Purpose: To determine the effect of glycerin on the surface hardness and roughness of nanofill composite. Material and Methods: 64 specimens of composite (Z350 XT, 3M) were prepared using a disc-shaped acrylic. The groups were divided into group A surface hardness (N=32) and group B surface roughness (N=32). Group A1, the specimen was coated with glycerin and light cured for 20 s and group A2, the specimen was exposed to air and light cured for 20 s. Group B1 was coated with glycerin and light cured for 20 s and Group B2 was exposed to air and light cured for 20 s. The specimens were stored in distilled water for 24 h at 370. Measuring with Vickers and surface roughness tester and. Data were statistically analyzed using Mean-whitney U Test. Results: There were statiscally significant difference between the surface hardness and roughness of nanofill composite coated with glycerin and without glycerin (p<0,05) Conclusion: The surface hardness of nanofill composite resin coated with glycerin is higher than composite without glycerin and the surface roughness of nanofill composite resin coated with glycerin is lower than composite without glycerin

Pengaruh Perendaman Air Perasan Jeruk Lemon dan Asam Cikala Terhadap Kekasaran Permukaan Resin Komposit Nanofiller

“…Resin komposit nanofiller dikembangkan untuk memperbaiki kekurangan yang dimiliki resin komposit generasi-generasi sebelumnya seperti mikrofiller dan mikrohibrid karena memiliki efek pemolesan yang lebih baik daripada mikrofiller dan memiliki sifat mekanik yang kuat seperti resin komposit mikrohibrid, yakni berupa kekuatan tekan, kekuatan tarik, dan tingkat keausan (Anusavice, 2013;Asiri et al, 2019). Kombinasi yang unik yaitu nano partikel individual dan nanocluster partikel filler yang berukuran nano (5-20 nm) akan mengurangi jumlah ruang interstistial antara partikel filler, sehingga dapat meningkatkan sifat fisik dan hasil poles yang lebih baik bila dibandingkan dengan resin komposit lain (Rusmayanti et al, 2017) Kehalusan permukaan bahan restorasi perlu dijaga, karena permukaan restorasi komposit yang kasar melebihi batas kritis 0,2 μm menyebabkan risiko terbentuknya plak, karies sekunder, perubahan warna, kerusakan permukaan dan warna tumpatan serta dapat menyebabkan iritasi pada jaringan lunak sekitar (Ansuj et al, 2016;Kawai et al, 2000;Zakiyah et al, 2018) Salah satu faktor yang mempengaruhi kekasaran adalah cairan di dalam rongga mulut yang diserap resin komposit yang berasal dari saliva, maupun makanan dan minuman yang dikonsumsi sehari-hari (Muawanah et al, 2012) Paparan makanan yang bersifat asam dan ber pH rendah < 7 dapat menyebabkan kerentanan erosi pada permukaan tumpatan dan gigi (Erdemir et al, 2016). Lingkungan yang asam akibat makanan dan minuman yang dikonsumsi terus menerus memiliki kelebihan ion H+ menyebabkan terjadinya ketidakstabilan ikatan kimia pada resin komposit sehingga menyebakan degradasi.…”

The Microhardness and Surface Roughness Assessment of Bulk-Fill Resin Composites Treated with and without the Application of an Oxygen-Inhibited Layer and a Polishing System: An In Vitro Study

“…Studies [ 12 , 13 , 14 ] have revealed the importance of resin composite reaction to polymerization in the presence of atmospheric oxygen, as this can affect the surface layer of the resin composite by producing free radicals that can bind to the Bis-GMA monomer and oxygen itself. These oxygen-free radical bonds are characterized by the formation of a stable peroxide radical and are non-reactive.…”

“…This layer contains the residual monomers which, due to decreased conversion, obtain less hardness on the resin composite surface [ 13 ]. Its thickness varies from 2.5 to 50 µm, in visible light-cured resin composites [ 14 ]. Due to this, the use of glycerin is recommended before light-curing the last layer of resin composite, as it forms a physical barrier that optimizes the conditions of light-curing processes by acting as an inhibitor of atmospheric oxygen that converts highly reactive radicals into relatively stable hydroperoxides, allowing a better curing quality in the outermost layer of composite resins [ 15 , 16 ].…”

“…The superficial microhardness of resin composites is important for the clinical success of restoration, since the higher the microhardness of restorative material, the better the resistance to surface wear and scratching [ 10 , 11 ]. Therefore, it is important to improve this mechanical property on the surface by subjecting it to polishing procedures, eliminating rough surfaces that would eventually affect the resin composites’ resistance to chewing forces, since small surface reliefs can fracture and facilitate the retention of bacterial plaque and even facilitate the formation of secondary caries [ 12 , 13 , 14 ].…”