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"Latar Belakang: Bahan berbasis resin, termasuk resin komposit dan semen ionomer kaca yang dimodifikasi dengan resin (RMGIC), telah menjadi pilihan optimal untuk restorasi gigi, menawarkan kekuatan mekanis dan estetika. Namun, paparan bahan pemutih, khususnya hidrogen peroksida 35%, dapat mengganggu integritas permukaan material tersebut. Tujuan: Penelitian ini bertujuan untuk menyelidiki pengaruh bahan pemutih 35% terhadap kekerasan mikro RMGIC dan resin komposit mikrohibrid. Bahan dan Metode: Sebanyak 20 spesimen, resin komposit mikrohibrid (n=10) dan RMGIC (n=10), dipolimerisasi menggunakan unit curing LED selama 20 detik. Setelah polimerisasi, spesimen direndam dalam aquadest selama 24 jam dan kemudian disimpan dalam inkubator pada suhu 37°C. Semua spesimen dikeringkan, dan kekerasan mikro awalnya diukur menggunakan metode Vickers. Spesimen kemudian diberi perlakuan dengan agen pemutih hidrogen peroksida 35% dengan waktu paparan 15 menit per aplikasi, yang diulang sebanyak tiga siklus. Kekerasan mikro Vickers diukur pada lima titik berbeda pada setiap sampel di setiap interval pengujian, dimulai sebelum perlakuan pemutihan. Analisis statistik dilakukan menggunakan uji T-berpasangan dan uji T- independen untuk menilai dan membandingkan variasi kekerasan mikro antar kelompok. Nilai p kurang dari 0,05 dianggap signifikan secara statistik. Hasil: Resin komposit mikrohibrid menunjukkan nilai kekerasan mikro yang lebih tinggi sebelum pemutihan dibandingkan RMGIC. Setelah paparan agen pemutih hidrogen peroksida 35%, perubahan kekerasan mikro pada spesimen resin komposit mikrohibrid dan RMGIC diamati. Perbedaan nilai kekerasan mikro sebelum dan sesudah pemutihan signifikan secara statistik (p=0,000). Resin komposit mikrohibrid menunjukkan penurunan kekerasan mikro yang lebih besar dibandingkan RMGIC (p=0,000). Kesimpulan: Aplikasi hidrogen peroksida 35% mengakibatkan penurunan kekerasan mikro pada resin komposit mikrohibrid dan RMGIC, dengan penurunan yang lebih signifikan terjadi pada resin komposit mikrohibrid.

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Background : Resin based materials, including composite resins and resin-modified glass ionomer cements (RMGIC), have emerged as an optimal choice for dental restorations, offering both mechanical strength and aesthetic properties. However, exposure to bleaching agents, particularly 35%hydrogen peroxide , can compromise the material’s surface integrity. Objective : This study aims to investigate the effect of 35% bleaching agents affect the microhardness of RMGIC and microhybrid resin composites. Materials and method : A total of 20 specimens, microhybrid composite resins (n=10) and RMGIC (n=10), were polymerized using LED curing unit for 20 seconds. Following polymerization, the specimens were immersed in aquadest for 24 hours and subsequently stored in an incubator for at 37°C. All of the specimen were dried and their baseline Vickers microhardness was measured. The specimens were then subjected to 35% hydrogen peroxide bleaching agent with a 15-minute exposure per application, repeated for three cycles. Vickers microhardness was measured at five distinct points on each sample at each testing interval, starting before the bleaching treatment. Statistical analysis was performed using paired T-tests and independent T-tests to assess and compare the variations in microhardness across the groups. A p-value of less than 0.05 was considered statistically significant. Results : The microhybrid composite resins exhibited higher microhardness values prior to bleaching compared to RMGIC. Following exposure to 35% hydrogen peroxide bleaching agent, changes in the microhardness of both microhybrid composite resin and RMGIC specimens were observed. The differences in the microhardness values before and after bleaching, were statistically significant (p=0.000). Microhybrid composite resin shows a greater reduction of microhardness compared to RMGIC (p=0.000). Conclusion : The application of 35% hydrogen peroxide results in a reduction in microhardness for both microhybrid composite resin and RMGIC, with a more significant decrease observed in microhybrid composite resin."

"Latar Belakang: Bahan berbasis resin, termasuk resin komposit dan semen ionomer kaca yang dimodifikasi dengan resin (RMGIC), telah menjadi pilihan optimal untuk restorasi gigi, menawarkan kekuatan mekanis dan estetika. Namun, paparan bahan pemutih, khususnya hidrogen peroksida 35%, dapat mengganggu integritas permukaan material tersebut. Tujuan: Penelitian ini bertujuan untuk menyelidiki pengaruh bahan pemutih 35% terhadap kekerasan mikro RMGIC dan resin komposit mikrohibrid. Bahan dan Metode: Sebanyak 20 spesimen, resin komposit mikrohibrid (n=10) dan RMGIC (n=10), dipolimerisasi menggunakan unit curing LED selama 20 detik. Setelah polimerisasi, spesimen direndam dalam aquadest selama 24 jam dan kemudian disimpan dalam inkubator pada suhu 37°C. Semua spesimen dikeringkan, dan kekerasan mikro awalnya diukur menggunakan metode Vickers. Spesimen kemudian diberi perlakuan dengan agen pemutih hidrogen peroksida 35% dengan waktu paparan 15 menit per aplikasi, yang diulang sebanyak tiga siklus. Kekerasan mikro Vickers diukur pada lima titik berbeda pada setiap sampel di setiap interval pengujian, dimulai sebelum perlakuan pemutihan. Analisis statistik dilakukan menggunakan uji T-berpasangan dan uji T- independen untuk menilai dan membandingkan variasi kekerasan mikro antar kelompok. Nilai p kurang dari 0,05 dianggap signifikan secara statistik. Hasil: Resin komposit mikrohibrid menunjukkan nilai kekerasan mikro yang lebih tinggi sebelum pemutihan dibandingkan RMGIC. Setelah paparan agen pemutih hidrogen peroksida 35%, perubahan kekerasan mikro pada spesimen resin komposit mikrohibrid dan RMGIC diamati. Perbedaan nilai kekerasan mikro sebelum dan sesudah pemutihan signifikan secara statistik (p=0,000). Resin komposit mikrohibrid menunjukkan penurunan kekerasan mikro yang lebih besar dibandingkan RMGIC (p=0,000). Kesimpulan: Aplikasi hidrogen peroksida 35% mengakibatkan penurunan kekerasan mikro pada resin komposit mikrohibrid dan RMGIC, dengan penurunan yang lebih signifikan terjadi pada resin komposit mikrohibrid.

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Background : Resin based materials, including composite resins and resin-modified glass ionomer cements (RMGIC), have emerged as an optimal choice for dental restorations, offering both mechanical strength and aesthetic properties. However, exposure to bleaching agents, particularly 35%hydrogen peroxide , can compromise the material’s surface integrity. Objective : This study aims to investigate the effect of 35% bleaching agents affect the microhardness of RMGIC and microhybrid resin composites. Materials and method : A total of 20 specimens, microhybrid composite resins (n=10) and RMGIC (n=10), were polymerized using LED curing unit for 20 seconds. Following polymerization, the specimens were immersed in aquadest for 24 hours and subsequently stored in an incubator for at 37°C. All of the specimen were dried and their baseline Vickers microhardness was measured. The specimens were then subjected to 35% hydrogen peroxide bleaching agent with a 15-minute exposure per application, repeated for three cycles. Vickers microhardness was measured at five distinct points on each sample at each testing interval, starting before the bleaching treatment. Statistical analysis was performed using paired T-tests and independent T-tests to assess and compare the variations in microhardness across the groups. A p-value of less than 0.05 was considered statistically significant. Results : The microhybrid composite resins exhibited higher microhardness values prior to bleaching compared to RMGIC. Following exposure to 35% hydrogen peroxide bleaching agent, changes in the microhardness of both microhybrid composite resin and RMGIC specimens were observed. The differences in the microhardness values before and after bleaching, were statistically significant (p=0.000). Microhybrid composite resin shows a greater reduction of microhardness compared to RMGIC (p=0.000). Conclusion : The application of 35% hydrogen peroxide results in a reduction in microhardness for both microhybrid composite resin and RMGIC, with a more significant decrease observed in microhybrid composite resin."

"Tujuan: Penelitian ini bertujuan untuk membandingkan perubahan warna pada resin komposit nanohibrida sebelum dan setelah bleaching dalam perendaman kopi. Metode: Dua puluh spesimen resin komposit nanohibrida berbentuk silinder berdiameter 6 mm, tebal 2 mm dibagi menjadi 2 kelompok perendaman; Arabika dan Robusta n=10. Masing-masing kelompok perendaman direndam dalam waktu 7 hari, kemudian diaplikasikan bahan bleaching berupa hidrogen peroksida 40, dan setelah itu direndam kembali selama 7 hari. Pengukuran warna dilakukan sebanyak 4 kali menggunakan Colorimeter. Data dianalisis menggunakan uji statistik Paired T-Test dan Independent T-Test. Hasil penelitian menunjukkan adanya perbedaan signifikan.

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Aim This study aims to compare color changes in nanohybrid composite resins before and after bleaching in coffee immersion. Method Twenty specimens of nanohybrid composite resins were made into cylindrical shape with a diameter of 6 mm and thick of 2 mm divided into 2 immersion groups Arabica and Robusta n 10. Each immersion group was immersed within 7 days, then applied bleaching material of hydrogen peroxide 40, and after that was re immersed for 7 days. The color measurement was done 4 times by Colorimeter. Data were analyzed statistically by Paired T Test and Independent T Test. Result The result showed significant differences."

"Penelitian ini bertujuan untuk menganalisis pengaruh hidrogen peroksida 40 terhadap perubahan warna resin komposit nanohibrida oleh larutan teh. Dua puluh spesimen berdiameter 6 mm dan tebal 2 mm dibagi menjadi dua kelompok. Setiap kelompok direndam pada larutan teh hijau atau teh hitam selama 7 hari, kemudian di bleaching dan direndam kembali selama 7 hari. Perubahan warna diukur menggunakan colorimeter. Hasil penelitian menunjukkan bahwa terdapat perbedaan bermakna p0,05 antara perubahan warna teh hijau dan teh hitam setelah bleaching. Dapat disimpulkan bahwa hidrogen peroksida 40 mempengaruhi perubahan warna resin komposit nanohibrida.

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This study aims to analyze the influence of 40 hydrogen peroxide on color change of nanohybrid composite resins by tea solution. Twenty specimens, 6 mm in diameter and 2 mm thick were divided into two groups. Each group was immersed in green tea or black tea for 7 days, then bleached and re immersed for 7 days. The color change is measured using a colorimeter. The results showed that there were statistically significant differences p 0.05 between green tea and black tea after bleaching. It can be concluded that 40 Hidrogen Peroxide affects colous change of nanohybrid composite resin."

"Penelitian ini bertujuan untuk mengetahui pengaruh aplikasi hidrogen peroksida 40 terhadap kerentanan perubahan warna resin komposit nanohibrida oleh minuman berkarbonasi. Tiga puluh spesimen resin komposit nanohibrida berbentuk silinder diameter 6mm x ketebalan 2mm dibagi menjadi tiga kelompok; Coca-Cola, Fanta Strawberry, dan Sprite n=10. Seluruh spesimen direndam dalam minuman masing-masing selama 7 hari, diaplikasikan hidrogen peroksida 40, dan direndam kembali selama 7 hari. Pengukuran warna dilakukan sebanyak empat kali dengan Colorimeter. Nilai perubahan warna kemudian dihitung. Data dianalisis menggunakan uji statistik Paired-Samples T Test dan One-Way ANOVA.

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This study aims to analyze the effect of 40 hydrogen peroxide application on nanohybrid composite resin staining susceptibility by carbonated drinks. Thirty cylindrical specimens 6mm diameter x 2mm depth of nanohybrid composite resin were divided into 3 groups Coca Cola, Fanta Strawberry, and Sprite n 10. All specimens were immersed in each drinks for 7 days, bleached with 40 hydrogen peroxide, and re immersed for 7 days. Color measurement was done four times using a Colorimeter. Color differences between each measurement were calculated. Data were analyzed statistically by Paired Samples T Test and One Way ANOVA. "

"Elektrolisis plasma menjadi metode sintesis green hydrogen dan hidrogen peroksida yang memisahkan air menjadi gas H2 dan O2 dengan plasma katodik pada tegangan di atas elektrolisis konvensional akibat rekombinasi radikal H• dan •OH. Laju erosi elektroda akibat suhu plasma yang tinggi menjadi keterbatasan pada proses ini sehingga Stainless Steel SS – 201 yang memiliki laju erosi lebih kecil dibandingkan tungsten (Lukkes, et al. 2006) diteliti efektivitasnya dari jumlah mmol produk, energi spesifik (Wr), dan laju erosi. Penelitian dilakukan dengan melakukan uji rancang bangun reaktor elektrolisis plasma dan karakterisasi arus tegangan untuk menentukan kondisi operasi menggunakan elektrolit NaOH 0,02 M dan Na2SO4 pada konduktivitas serupa, serta konsentrasi aditif metanol sebagai scavenger radikal •OH. Hasil penelitian menunjukkan bahwa SS – 201 memiliki erosi yang lebih kecil sebesar 0,07 gram dibandingkan tungsten sebesar 1,05 gram setelah 60 menit proses. Pembentukan lapisan oksida pasif SS – 201 menambah luas kontak elektroda dan menghasilkan gas H2 sebanyak 104,55 mmol dibandingkan tungsten sebanyak 94,95 mmol. Penelitian ini juga membandingkan pengaruh penggunaan NaOH dan Na2SO4 dengan konduktivitas serupa yang menunjukkan NaOH menghasilkan lebih banyak H2 dibandingkan Na2SO4 sebanyak 97,55 mol karena cenderung mengarah pada produksi hidrogen peroksida karena komposisi elektrolit yang mendorong pembentukan radikal •OH. Selain itu, pengaruh variasi metanol diuji yang menunjukkan bahwa penambahan aditif metanol tidak hanya berperan sebagai scavenger radikal •OH namun terdekomposisi akibat plasma menghasilkan gas hidrogen dan radikal H•.

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Plasma electrolysis is a green hydrogen and hydrogen peroxide synthesis method that separates water into H2 and O2 gases with cathodic plasma at a voltage above conventional electrolysis due to the recombination of H• and •OH radicals. The electrode erosion rate due to high plasma temperature is a limitation in this process so that Stainless Steel SS – 201 which has a lower erosion rate than tungsten (Lukkes, et al. 2006) was examined for its effectiveness from the number of mmol of product, specific energy (Wr), and rate of erosion. The research was carried out by conducting design tests for plasma electrolysis reactors and characterizing current voltages to determine operating conditions using electrolytes of 0.02 M NaOH and Na2SO4 with similar conductivity, as well as the concentration of methanol additive as an •OH radical scavenger.

The results showed that SS-201 had less erosion of 0.07 gram compared to 1.05 gram of tungsten after 60 minutes of process. The formation of the SS-201 passive oxide layer increased the contact area of the electrodes and produced 104.55 mmol of H2 gas compared to 94.95 mmol of tungsten. This study also compared the effect of using NaOH and Na2SO4 with similar conductivity which showed that NaOH produced more H2 than Na2SO4 of 97.55 mmol because it tends to produce of hydrogen peroxide due to the electrolyte composition which encourages the formation of •OH radicals. In addition, the effect of methanol variations was tested which showed that the addition of additive methanol did not only act as an •OH radical scavenger but decomposed due to plasma to produce hydrogen gas and H• radicals."

"Latar Belakang: Melihat potensi tingginya jumlah virus didalam rongga mulut, dengan bukti bahwa SARS-CoV-2 ditemukan pada reseptor ACE2, perlu upaya untuk mencegah penularan dari pasien ke praktisi melalui saliva yang terkontaminasi. Virus ini menyebar lebih cepat karena SARS-CoV-2 bereplikasi disaluran pernapasan bagian atas dengan melepaskan patogen yang berpindah dari satu orang ke orang lain saat bersin dan batuk melalui penyebaran pernapasan. Diperkirakan waktu penularan bisa terjadi sebelum gejala muncul (sekitar 2,5 hari lebih awal dari munculnya gejala). Berkumur dengan hidrogen peroksida dapat menghilangkan lapisan permukaan epitel pada mukosa mulut yang diketahui terdapat reseptor ACE2 tempat terikatnya SARS- CoV-2 dan dapat menginaktivasi virus tersebut. Pedoman sementara American Dental Association (ADA) menyarankan penggunaan 1,5% Hidrogen peroksida sebagai pilihan untuk pembilasan mulut preoperatif sebagai obat kumur antiseptik. Nilai cycle threshold yang diperoleh RT – PCR bersifat semi-kuantitatif dan mampu membedakan antara viral load tinggi dan rendah. Tujuan Penelitian: Mengevaluasi perbedaan pengaruh penggunaan obat kumur diantara berkumur hidrogen peroksida 1,5% dan hidrogen peroksida 3% terhadap nilai cycle threshold RT-PCR pada pasien COVID - 19. Metode Penelitian: 42 subjek penelitian diambil dari pasien RSUP Persahabatan yang terinfeksi SARS-CoV-2 sesuai dengan kriteria inklusi dan ekslusi. Setelah dilakukan informed consent, subjek penelitian dibagi menjadi 3 kelompok, yaitu kelompok hidrogen peroksida 1,5%, kelompok hidrogen peroksida 3% dan kelompok kontrol. Subjek penelitian berkumur 30 detik di rongga mulut dan 30 detik di tenggorokan belakang dengan 15 ml sebanyak 3 kali sehari selama 5 hari. Analisis menggunakan nilai cycle threshold pada pemeriksaan RT-PCR pada hari ke-1, hari ke-3 dan hari ke-5 setelah berkumur. Hasil: Terdapat perbedaan bermakna pada hasil uji Friedman dan peningkatan nilai cycle threshold RT-PCR dari awal, hari ke-1, hari ke-3 dan hari ke-5 di keseluruhan kelompok dan masing – masing kelompok perlakuan. Peningkatan tertinggi nilai cycle threshold RT-PCR awal hingga hari ke-1 ditemukan pada kelompok hidrogen peroksida 3%, kemudian antara hari ke-1 hingga ke-3 dan hari ke-3 hingga hari ke-5 ditemukan pada kelompok hidrogen peroksida 1,5%. Kesimpulan: Berkumur hidrogen peroksida 1,5% dan hidrogen peroksida 3% berpengaruh terhadap peningkatan nilai cycle threshold RT-PCR SARS-CoV-2. Kedua konsentrasi hidrogen peroksida 1,5% dan hidrogen peroksida 3% memberikan pengaruh positif dalam menurunkan jumlah virus di rongga mulut, sehingga pilihan penggunaan konsentrasi hidrogen peroksida yang lebih kecil bisa menjadi pilihan untuk digunakan untuk berkumur.

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Background: Given the potential high number of viruses in the oral cavity, with evidence that SARS-CoV-2 is found at the ACE2 receptor, efforts are needed to prevent transmission from patient to practitioner through contaminated saliva. This virus spreads faster because SARS-CoV-2 replicates in the upper respiratory tract by releasing pathogens that are passed from one person to another when sneezing and coughing through respiratory spread. It is estimated that the time of transmission can occur before symptoms appear (about 2.5 days earlier than the onset of symptoms). Mouth rinse and gargling with hydrogen peroxide can remove the epithelial surface layer on the oral mucosa which is known to have ACE2 receptors where SARS-CoV-2 binds and can inactivate the virus. Interim guidelines of the American Dental Association (ADA) recommend the use of 1.5% hydrogen peroxide as an option for preoperative oral rinse as an antiseptic mouth rinse. The cycle threshold value obtained by RT-PCR is semi-quantitative and able to distinguish between high and low viral loads.

Objective: To evaluate the difference in the effect of using mouth rinse between 1.5% hydrogen peroxide and 3% hydrogen peroxide mouth rinse and gargling on the RT-PCR cycle threshold value in COVID-19 patients.

Methods: 42 subjects were patients recruited from Persahabatan General Hospital infected with SARS-CoV-2 according to the inclusion and exclusion criteria. Following informed consent procedure, the research subjects were divided into 3 groups, namely the 1.5% hydrogen peroxide group, the 3% hydrogen peroxide group and the control group. The subjects were instructed to rinse their mouths for 30 seconds and gargle for 30 seconds at the back of the throat with 15 ml of the mouth rinse 3 times a day for 5 days. Analysis of cycle threshold values was carried out using RT-PCR on day 1, day 3 and day 5 after mouth rinse and gargling.

Results: There were significant differences in the results of the Friedman test and an increase in the RT-PCR cycle threshold value starting from the beginning, day 1, day 3 and day 5 in the whole group and each treatment group. The highest increase RT-PCR cycle threshold value at day 1 was found in the 3% hydrogen peroxide group, while the increase between day 1 to 3 and day 3 to day 5 was found in the 1.5% hydrogen peroxide group.

Conclusion: Mouth rinse and gargling with 1.5% hydrogen peroxide and 3% hydrogen peroxide has an effect on increasing the cycle threshold value of the SARS-CoV-2 RT-PCR. Both 1.5% and 3% hydrogen peroxide concentration have a positive effect in reducing the number of viruses in the oral cavity, so the choice of using a lower hydrogen peroxide concentration can be an option to use for mouth rinse and gargling."

"Penelitian ini bertujuan untuk memperbaiki kualitas limbah sefadroksil dengan menggunakan proses perokson, yaitu suatu proses AOPs yang menggabungkan ozon yang berfase gas dan hidrogen peroksida yang berfase cair sebagai oksidator. Ozon yang digunakan berasal dari ozonator yang mampu menghasilkan ozon pada fase cair dan gas-cair kemudian langsung dicampurkan dengan H2O2. Variasi yang digunakan untuk melakukan uji kinerja proses perokson ini adalah rasio ozon terhadap hidrogen peroksida. Dari penelitian ini menghasilkan kondisi terbaik untuk degradasi limbah cair sefadroksil sintetik, yaitu ozon dengan rasio hidrogen peroksida sebesar 1;0,5. Persentase degradasi yang dihasilkan mencapai 86,04% dengan konsentrasi akhir 6,98 ppm dan ozon, reaktor hibrida ozon-plasma, dan rasio hidrogen peroksida sebesar 1:0,5. Persentase degradasi yang dihasilkan mencapai 82,12% dengan konsentrasi akhir 8,94 ppm.

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The aim of this research is to improve the quality of cefadroxil wastewater using peroxone process, an AOPs which combines ozone and hydrogen peroxide as an oxidizer. Ozone came from ozonator which capable of producing ozone in the liquid phase and gas-liquid then mixed with H2O2. Variation of variables used are ratio of ozone to hydrogen peroxide. From this research, produced the best conditions for the degradation of synthetic wastewater cefadroxil are ozone with hydrogen peroxide ratio of 1:0.5. The result degradation percentage reached 86,04% with a final concentration of 6,98 ppm and combine of ozone, hybrid plasma ozone reactor and hydrogen peroxide ratio of 1:0.5. The result degradation percentage reached 82,12% with a final concentration of 8,94 ppm.;The aim of this research is to improve the quality of cefadroxil wastewater

using peroxone process, an AOPs which combines ozone and hydrogen peroxide

as an oxidizer. Ozone came from ozonator which capable of producing ozone in

the liquid phase and gas-liquid then mixed with H2O2. Variation of variables used

are ratio of ozone to hydrogen peroxide. From this research, produced the best

conditions for the degradation of synthetic wastewater cefadroxil are ozone with

hydrogen peroxide ratio of 1:0.5. The result degradation percentage reached

86,04% with a final concentration of 6,98 ppm and combine of ozone, hybrid

plasma ozone reactor and hydrogen peroxide ratio of 1:0.5. The result degradation

percentage reached 82,12% with a final concentration of 8,94 ppm."

"Latar Belakang: Material restorasi gigi seperti resin komposit mikrohibrid dan semen ionomer kaca modifikasi resin (RMGIC) banyak digunakan karena kekuatan estetika dan mekanisnya. Dengan meningkatnya perawatan pemutihan gigi, muncul kekhawatiran tentang efek bahan pemutih terhadap sifat mekanis material-material ini, terutama karena terbatasnya penelitian tentang kinerja jangka panjang setelah paparan pemutihan. Tujuan: Penelitian ini bertujuan untuk mengevaluasi dampak pemutihan in-office menggunakan hidrogen peroksida 35% terhadap DTS resin komposit mikrohibrid dan RMGIC. Metode: Penelitian eksperimental in vitro ini dilakukan pada 40 spesimen silindris (diameter 6 mm × tinggi 3 mm) yang dibagi menjadi empat kelompok resin komposit mikrohibrid dan RMGIC, dengan dan tanpa pemutihan. Setelah penyinaran LED (1300 mW/cm , 20 detik) dan penyimpanan dalam air suling (37°C, 24 jam), spesimen menjalani pemutihan menggunakan hidrogen peroksida 35% selama tiga siklus 15 menit. DTS diukur menggunakan universal testing machine, dan hasilnya dianalisis dengan analisis statistik. Hasil: DTS resin komposit mikrohibrid sedikit menurun setelah pemutihan in-office dari 47,37 ± 9,24 MPa menjadi 46,94 ± 7,02 MPa, sementara RMGIC menunjukkan penurunan dari 13,04 ± 0,96 MPa menjadi 12,71 ± 1,82 MPa. Perubahan ini tidak signifikan secara statistik (p > 0,05), dengan resin komposit mikrohibrid tetap mempertahankan DTS yang secara signifikan lebih tinggi dibandingkan RMGIC (p = 0,001). Kesimpulan: Aplikasi pemutihan in-office menggunakan hidrogen peroksida 35% memiliki efek minimal dan tidak signifikan secara statistik terhadap DTS resin komposit mikrohibrid dan RMGIC, menunjukkan keamanan untuk penggunaan klinis, meskipun penelitian lebih lanjut tentang efek jangka panjang direkomendasikan.

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Background: Dental restorative materials such as microhybrid composite resin and resin modified glass ionomer cement (RMGIC) are widely used for their combination of aesthetic appeal and mechanical strength. With the growing popularity of tooth-whitening treatments, there is increasing concern about how bleaching agents might affect these materials' mechanical properties. While existing studies indicate that in-office bleaching treatments generally have minimal impact on the diametral tensile strength (DTS) of composite resins Despite the insights provided by prior studies, there is limited information regarding how these interactions might affect the long-term mechanical properties of microhybrid composite resins. Additionally, research on RMGIC's response to bleaching remains scarce, underscoring the importance of studying its mechanical performance after exposure to in-office bleaching agents. Objective: This study aimed to evaluate the impact of 35% hydrogen peroxide bleaching on the DTS of microhybrid composite resin and RMGIC. Methods: This experimental in vitro study was conducted on 40 cylindrical specimens (6 mm diameter × 3 mm height) divided into four groups: microhybrid composite resin (with and without bleaching) and RMGIC (with and without bleaching). Specimens were cured with a second-generation LED curing unit (1300 mW/cm , 20 seconds) and stored in distilled water at 37°C for 24 hours. Bleaching was performed using 35% hydrogen peroxide for three 15-minute cycles. DTS was measured using a universal testing machine, and the results were analyzed with paired t-tests. Results: The DTS of microhybrid composite resin slightly decreased after in-office bleaching (from 47.37 ± 9.24 MPa to 46.94 ± 7.02 MPa), while RMGIC showed a decrease from 13.04 ± 0.96 MPa to 12.71 ± 1.82 MPa. These changes were not statistically significant (p > 0.05). Comparisons between materials revealed that microhybrid composite resin exhibited significantly higher DTS than RMGIC both before and after in-office bleaching (p = 0.001). Conclusion: The application of 35% hydrogen peroxide in-office bleaching had minimal and statistically insignificant effects on the DTS of microhybrid composite resin and RMGIC, suggesting that short-term bleaching protocols are safe for these materials. Further studies are needed to investigate the long-term effects and repeated in-office bleaching cycles to ensure material durability in clinical settings."