Non-Diamond addition with decreased repair gap improves flexural and impact strength of repaired denture resin: study

This study aimed to evaluate the effect of nanodiamond (ND) addition to repair resin with repair gap modifications on the flexural and impact strength of repaired polymethylmethacrylate denture base.

Heat-polymerized acrylic resin specimens (N = 100/test) were prepared and sectioned to half creating two repair gaps: 2.5- and 0 mm with 45 degrees beveling. They were further divided into subgroups (n = 20) according to Non-Diamond concentration (control, 0.25%ND, and 0.50%ND), thermocycling (500 cycles) was done to half the specimens in each subgroup. Flexural strength was tested using 3-point bending test and impact strength was tested by Charpy's impact test. Analysis of variance and post-hoc Tukey's tests were performed for data analysis (α = 0.05). Scanning electron microscope was employed for fracture surface analysis and Non-Diamond distribution.

Results 

• Before and after thermocycling, the addition of Non-Diamond significantly increased the flexural strength and elastic modulus in comparison to control group while 0 mm repair gap showed insignificant difference between Non-Diamond -reinforced groups
• Regarding impact strength, Non-Diamond addition increased the impact strength with 0 mm gap in comparison to control and 2.5 mm with ND while later groups showed no significant in between
• Comparing thermocycling effect per respective concentration and repair gap, thermocycling adversely affected all tested properties except elastic modulus with 0 mm–0.25 and 0 mm–0.5% and impact strength with 2.5 mm, 2.5 mm–0.25%, 2.5 mm– 0.5%

Non-Diamond addition combined with decreased repair gap improved the flexural strength, elastic modulus, and impact strength of repaired denture resin, while thermocycling has a negative effect on denture repair strength.

Reference:

Mohammed M. Gad , Mohamed Saber Ali, et al. Polymethylmethacrylate Incorporating Nanodiamonds for Denture Repair: In Vitro Study on the Mechanical Properties.

CC BY 4.0 · Eur J Dent 2022; 16(02): 286-295

DOI: 10.1055/s-0041-1735792

Keywords:

Non-Diamond, decreased, repair, gap, improves, flexural, impact, strength, repaired, denture, resin, Mohammed M. Gad , Mohamed Saber Ali , Ahmad M. Al-Thobity , Yousif A. Al-Dulaijan , Mai El Zayat , Abdel-Naser M. Emam , Sultan Akhtar , Soban Q. Khan , Fahad A. Al-Harbi , Shaimaa M. Fouda, thieme