Effect of Restorative Cavity Designs and Restoration Techniques on Fracture Resistance and Fracture Patterns in Simulated Immature Teeth: An In Vitro Study

Merve Sarı; Şule Pekuz; Pelin Tufenkci

doi:10.7126/cumudj.1805743

EN TR

Effect of Restorative Cavity Designs and Restoration Techniques on Fracture Resistance and Fracture Patterns in Simulated Immature Teeth: An In Vitro Study

Abstract

Objectives: This study evaluated the effects of different restorative techniques—direct composite, fiber post, and the Bioblock technique—on the fracture resistance and fracture patterns of simulated immature teeth with mesio-occlusal (MO) and single buccal cusp (SBC) cavity designs. Materials and Methods: Seventy single-rooted mandibular premolars were selected. Ten teeth served as the control group, while the remaining specimens were randomly allocated into six experimental groups (n=10) according to cavity design (MO or SBC) and restorative technique (direct composite, fiber post, or Bioblock). To simulate immature apices, root canals were enlarged using Gates Glidden drills, followed by apexification with a 3-mm-thick MTA layer. All specimens then underwent fracture resistance testing. Fracture resistance data were analyzed using one-way analysis of variance (ANOVA), while fracture pattern data were evaluated with the chi-square test. The level of statistical significance was set at α = 0.05. Results: The lowest fracture resistance was observed in the SBC fiber post group, while the control group exhibited the highest values. All MO subgroups demonstrated significantly higher fracture resistance than the SBC subgroups (p<0.01). No significant difference was found between the direct composite and Bioblock groups (p>0.05); however, both exhibited significantly greater fracture resistance than the fiber post groups (p<0.01). No significant differences were observed in fracture patterns among the groups (p>0.05). Conclusion: MO cavity designs provided greater fracture resistance compared with SBC designs. Fiber post restorations yielded the lowest resistance values, whereas direct composite and Bioblock techniques performed significantly better.

Keywords

Restoratif Kavite Tasarımlarının ve Restorasyon Tekniklerinin Simüle Edilmiş İmmatür Dişlerde Kırılma Direnci ve Kırılma Paternleri Üzerine Etkisi: İn Vitro Çalışma

Öz

Amaç: Bu çalışma, farklı restoratif tekniklerin—direkt kompozit, fiber post ve Bioblock tekniği—mezio-okal (MO) ve tek bukkal kusp (SBC) kaviteli simüle immatür dişlerde kırılma direnci ve kırılma paternleri üzerindeki etkilerini değerlendirmiştir. Gereç ve Yöntemler: Yetmiş tek köklü mandibular premolar diş seçilmiştir. On diş kontrol grubu olarak ayrılmış, kalan örnekler ise kavite tasarımı (MO veya SBC) ve restoratif teknik (direkt kompozit, fiber post veya Bioblock) esas alınarak rastgele altı deney grubuna (n=10) dağıtılmıştır. İmmatür apeksleri simüle etmek için kök kanalları Gates Glidden frezleriyle genişletilmiş ve ardından 3 mm kalınlığında MTA tabakası ile apeksifikasyon yapılmıştır. Tüm örneklerde kırılma direnci testi uygulanmıştır. Kırılma direnci verileri tek yönlü varyans analizi (ANOVA) ile, kırılma paterni verileri ise ki-kare testi ile değerlendirilmiştir. İstatistiksel anlamlılık düzeyi α = 0,05 olarak belirlenmiştir. Bulgular: En düşük kırılma direnci SBC fiber post grubunda gözlenirken, en yüksek değerler kontrol grubunda bulunmuştur. Tüm MO alt grupları, SBC alt gruplarına göre anlamlı derecede daha yüksek kırılma direnci göstermiştir (p<0,01). Direkt kompozit ve Bioblock grupları arasında anlamlı fark bulunmamıştır (p>0,05); ancak her ikisi de fiber post gruplarına kıyasla anlamlı derecede daha yüksek kırılma direnci sergilemiştir (p<0,01). Gruplar arasında kırılma paternleri açısından anlamlı farklılık gözlenmemiştir (p>0,05). Sonuçlar: MO kavite tasarımları, SBC tasarımlarına kıyasla daha yüksek kırılma direnci sağlamıştır. Fiber post restorasyonlar en düşük direnç değerlerini verirken, direkt kompozit ve Bioblock teknikleri anlamlı derecede daha iyi performans göstermiştir.

Anahtar Kelimeler

Supporting Institution

This study was funded by the Hatay Mustafa Kemal University Scientific Research Projects (Project No: 22.DHU.008).

Ethical Statement

This study was approved by the ... University, Non-Interventional Research Ethics Committee (Protocol Number: 06/05/2021-26). The authors certify that the study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. As this study did not involve human participants, Hatay Mustafa Kemal University Non-Interventional Research Ethics Committee determined that informed consent was not required.

Thanks

None

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Details

Primary Language

English

Subjects

Dental Materials and Equipment , Endodontics , Restorative Dentistry

Journal Section

Research Article

Authors

Merve Sarı ^*
0000-0002-9432-3809
Türkiye

Şule Pekuz
0000-0002-6563-1327
Türkiye

Pelin Tufenkci
0000-0001-9881-5395
Türkiye

Publication Date

March 27, 2026

Submission Date

October 17, 2025

Acceptance Date

February 26, 2026

Published in Issue

Year 2026 Volume: 29 Number: 1

DOI

https://doi.org/10.7126/cumudj.1805743

IZ

https://izlik.org/JA36TM67AD

Cite

RIS / Bibtex

EndNote

Sarı M, Pekuz Ş, Tufenkci P (March 1, 2026) Effect of Restorative Cavity Designs and Restoration Techniques on Fracture Resistance and Fracture Patterns in Simulated Immature Teeth: An In Vitro Study. Cumhuriyet Dental Journal 29 1 129–137.