Cytotoxicity Evaluation of INOX (Nanoksa G Plus) High- Performance Polymer Discs on Cell Cultures: An In-Vitro Experimental Study

INOX; Nanoksa G-Plus; scaffold; periodontal regeneration; peri-implant tissue engineering; cytocompatibility; osteogenic differentiation; fibroblasts; ALP; RUNX2; osteocalcin; MTT assay; DNA integrity; high-performance polymer

Ghada Gamal Adayil1*
BDS, M.Sc, PhD; Lecturer of
Periodontology, Department of Oral
Medicine and Periodontology, Faculty
of Dentistry, Cairo University, Email:
Ghada.adayil@dentistry.cu.edu.eg
ORCID: 0009-0007-0022-1558
Mihad Ibrahim2
BDS, M.Sc, PhD candidate, Department
of Periodontology, Faculty of Dentistry,
Cairo University, Email:
mihad.ibrahim@dentistry.cu.edu.eg
ORCID: 0009-0003-2127-9442
Hazem Ahmed Elsayed3
BDS, M.Sc candidate, Department of
Periodontology, Faculty of Dentistry,
Cairo University, Email:
hazem.elsayed@dentistry.cu.edu.eg
ORCID: 0009-0001-4123-0238
Marwa A. El-Saeed4
BDS, M.Sc, PhD, Lecturer of Oral
Biology, Department of Oral Biology,
Faculty of Dentistry, Cairo University,
Email:
marwa.elsaeed@dentistry.cu.edu.eg
ORCID:0000-0002-9090-2352

European Journal of Prosthodontics and Restorative Dentistry (2026) 34 (3s), 01-13

Cytotoxicity Evaluation of
INOX (Nanoksa G Plus) HighPerformance Polymer Discs
on Cell Cultures: An In-Vitro
Experimental Study

Background/Objectives: INOX (Nanoksa G-Plus) is a nano-reinforced highperformance polymer composed of a methacrylate-based matrix reinforced with nano-zirconia and nano-carbon fillers, currently used as a CAD/CAM restorative material for full-arch implant-supported frameworks and denture bases. Despite its increasing clinical use, comprehensive biological characterization, particularly its potential to support regenerative cellular responses, remains unexplored. The present study aimed to evaluate the cytocompatibility, osteogenic differentiation potential, and genotoxic profile of INOX in human fibroblasts, to establish its candidacy as a scaffold material for periodontal and peri-implant regeneration. Methods: Human skin fibroblast cells (HFB4); VACSERA, Cairo, Egypt, were exposed to two-fold serial dilutions of INOX extract 1500–0.73 µg/mL. Cytocompatibility was assessed using the MTT colorimetric viability assay ISO 10993-5. Osteogenic gene expression was quantified by real-time quantitative polymerase chain reaction (RT-qPCR) targeting alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN). DNA integrity was assessed by the diphenylamine (DPA) colorimetric assay and confirmed by agarose gel electrophoresis. Surface characteristics of the material and fibroblast morphology were further examined using scanning electron microscopy (SEM). Results: Cell viability ranged from 82.62% to 101.59% across all tested concentrations, consistently exceeding the 70% ISO 10993-5 non-cytotoxicity threshold. RT-qPCR revealed significant upregulation of ALP fold change: 2.96, RUNX2 fold change: 2.18, and OCN fold change: 3.18 in INOX-exposed fibroblasts relative to untreated controls. DNA fragmentation was minimal and comparable between groups: test: 2.14 ± 0.08%; control: 1.80 ± 0.05%, with agarose gel electrophoresis confirming predominant genomic integrity in both groups. Table 4: Percent DNA fragmentation and corresponding optical density OD values in % DNA Optical density fragmen

Received: 05.03.2026 Revised: 25.03.2026 Accepted: 29.04.2026

I N TS/HFB R 4 O D U C C/HF

∆T

S

∆B

T1

T2

tation

T

B1

B2

B3

3

2.144559

0.018

0.821

0.0

0.01

0.

0.8

0.8

0.8

333

22

7

0

23

19

22

1 5 1.800327

0.014 • 667

B4

0.8

0.0

0.01

0.

0.7

0.8

0.8

15

3

0

92

02

06

•

1

•

6

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