Effect of Different Fillers and Concentrations on the Flexural Strength of Heat-Polymerized PMMA Denture Base Resin

Abstract

Objective: The aim of the current study was to evaluate the effect of different nanofillers and their corresponding concentrations on the flexural strength of heat-polymerized PMMA denture base resin. Methods: A total of 110 PMMA specimens were produced according to ISO standards and divided into 11 groups (n = 10). PMMA was reinforced with titanium-dioxide (TiO₂), silicon-dioxide (SiO₂), graphitic carbon nitride (g-C₃N₄), multiwalled carbon nanotubes (MWCNTs), and cellulose nanofibrils (CNFs) at concentrations of 1 wt% and 2 wt%, while unreinforced PMMA served as the control group. A three-point bending assessment was utilized to measure the flexural strength. The results were put through analysis employing one-way ANOVA alongside Tukey's HSD post-hoc evaluations (α=.05). Results: Significant differences in flexural strength were observed among the groups (p<.05). The lowest mean flexural strength values were recorded for g-C₃N₄ (2%) (68.54 MPa) and MWCNTs (2%) (68.99 MPa). Within the TiO₂ groups, the 1% concentration (83.21 MPa) showed higher flexural strength than the 2% concentration (78.72 MPa), while CNF-reinforced PMMA demonstrated the highest flexural strength overall, with CNF (1%) demonstrating the maximum value (134.66 MPa), followed by CNF (2%) (129.94 MPa). Each experimental cohort surpassed the critical flexural strength standard specified by ISO 20795-1. Conclusions: The integration of nanofillers significantly affected the flexural strength of PMMA denture base resin. The reinforcing effect was strongly dependent on filler type and concentration. Among the tested materials, cellulose nanofibrils at 1 wt% provided the most effective reinforcement, whereas higher concentrations of several nanofillers adversely affected flexural strength.

Keywords

• Polymethyl methacrylate
• denture bases
• nanoparticles
• flexural strength
• titanium dioxide.

Supporting Institution

Atatürk University

Ethical Statement

Ethical approval of the study was received from the Committee for Ethics Research at the University of Atatürk (Date: 04/02/2026, Number: 05).

Farklı Nanodoldurucuların ve Konsantrasyonlarının Isıyla Polimerize Edilmiş PMMA Protez Kaide Rezininin Eğilme Dayanımına Etkisi

Abstract

Amaç: Bu çalışmanın amacı, farklı nanodoldurucuların ve konsantrasyonlarının ısı ile polimerize edilmiş polimetil metakrilat (PMMA) protez kaide materyallerinin eğilme dayanımı üzerindeki etkisini değerlendirmektir. Yöntemler: Toplam 110 adet PMMA numunesi ISO standartlarına göre üretildi ve 11 gruba (n = 10) ayrıldı. PMMA, %1 ve %2 ağırlık konsantrasyonlarında titanyum dioksit (TiO₂), silicon dioksit (SiO₂), grafit karbon nitrit (g-C₃N₄), çok duvarlı karbon nanotüpler (MWCNT) ve selüloz nanofibriller (CNF) ile takviye edildi; takviyesiz PMMA ise kontrol grubu olarak kullanıldı. Eğilme dayanımı, üç nokta eğilme testi kullanılarak ölçüldü. Veriler tek yönlü ANOVA ve Tukey HSD post-hoc testleri kullanılarak analiz edildi (α=.05). Bulgular: Gruplar arasında eğilme dayanımında önemli farklılıklar gözlemlendi (p<.05). En düşük ortalama eğilme dayanımı değerleri g-C₃N₄ (%2) ve MWCNT'ler (%2) için kaydedildi. TiO₂ için, %1'lik grup %2'lik gruba göre daha yüksek eğilme dayanımı gösterdi. CNF takviyeli PMMA en yüksek eğilme dayanımını sergiledi; CNF (%1) maksimum değeri gösterirken, onu CNF (%2) izledi. Tüm gruplar ISO 20795-1 tarafından belirtilen minimum eğilme dayanımı gereksinimini aştı. Sonuç: Nanodoldurucuların eklenmesi, PMMA protez kaide materyallerinin eğilme dayanımını önemli ölçüde etkilemiştir. Güçlendirme etkisi, dolgu maddesinin türüne ve konsantrasyonuna büyük ölçüde bağlıydı. Test edilen malzemeler arasında, %1 ağırlık oranındaki selüloz nanofibriller en etkili güçlendirmeyi sağlarken, çeşitli nanodoldurucuların daha yüksek konsantrasyonları eğilme dayanımını olumsuz etkilemiştir.

Keywords

• Polimetil metakrilat
• protez kaideleri
• nanodoldurucular
• eğilme dayanımı
• titanyum dioksit.

Supporting Institution

Atatürk Üniversitesi

Ethical Statement

Çalışmanın etik onayı Atatürk Üniversitesi Araştırma Etik Kurulu'ndan alınmıştır (Tarih: 04/02/2026, Sayı: 05)

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