Pusat Pengajian Sains Pergigian - Tesis
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- PublicationMobile application gigiku sihat to improve dietary habit and oral hygiene among children aged 4 to 6 years and dietary and oral health knowledge, attitude and practice among parents: a community intervention study in Kelantan(2025-04)Zulkefle, Rumaisa’Maintaining good oral health in children involves a combination level of parental knowledge, attitude, and persistent behavioral routines towards children’s nutrient and oral health. The ability of smartphone to overcome barriers in conventional education method is needed since more parents depend on it nowadays. In order to improve dietary habits and oral health, app of Gigiku Sihat (GS) was developed targeted to parents of preschool children. Aim of this study was to evaluate the effectiveness of mHealth apps Gigiku Sihat for improving dietary habits and oral health among 4- to 6-year-olds children at KEMAS preschool in Tumpat and Pasir Mas, Kelantan and their parents’ nutrition and oral health knowledge, attitude, and practice (KAP). A cluster randomized trial was done. During the study period, participants in the intervention group (IG) used GS installed in their mobile device, while the control group (CG) received TIP TOP which was delivered once during the first visit. The sample size was 60 for each IG and CG. Primary outcome measures including parental nutrition and oral health KAP and children’s cariogenic food frequency (CFF) were evaluated through validated self-administered questionnaires, and OH status was determined through clinical examination using Simplified Oral Hygiene Index (OHI-S). Measurement of variables were done at baseline, 4- (Evaluation 1) and 8-weeks (Evaluation 2) post-intervention. Descriptive analysis, independent t-test, and repeated measures ANOVA were performed with significance level set at p<0.05. A total of 116 parent-child pairs (IG:56, CG:60) completed the study. Both groups have more girls compared to boys. Majority of parents in both groups aged 30-39 years old (IG:73.2%, CG:53.3%); had finished secondary school as their highest education level (IG:48.2%, CG:66.7%); were housewife or not working (IG:41.1%, CG:68.3%); had less than 6 family members (IG:62.5%, CG:55%) and had monthly household income of RM1,000 - RM1,999 (IG: 32.1%, CG:45.0%). Most of parents in IG (35.7%) had spent RM500-RM599 monthly for food, while most of parents in CG (31.7%) had monthly expenditure of RM700-RM799. The main water supply for both groups was from AKSB (pipe water) (IG:69.6%, CG:73.3%). At Evaluation 1, IG showed significantly lower mean CFF score in the categories of biscuits (p=0.017), crisps (p=0.024, 0.003), soya bean-based milk (p=0.007) and sugared drinks /condensed milk (p=0.042). At Evaluation 2, significantly lower mean CFF scores was also observed in IG for traditional kuih (p=0.006), chocolate (p<0.001), crisps (p=0.003), sweets (p=0.047), processed fruits (p=0.002), soya bean-based milk (p<0.001) and sugared drinks /condensed milk (p=0.004). There was a significantly lower OHI-S score (p=0.023) and higher attitude score (p=0.041) at Evaluation 2 in IG as compared to CG. There was no significant difference in parental knowledge and practice scores between the IG and CG. GS was effective in improving parental attitude score, children’s oral health, as well as some categories of CFF of the preschool children. Mobile application, dietary habits, oral hygiene, KAP, preschool and parents.
- PublicationAntimicrobial enhancement of denture base resin using microcapsule drug delivery technology: a characterization study(2025-05)Mahadi, Nik Nur Syahidatul JannahDenture stomatitis (DS) presents as a common inflammatory reaction in denture wearing patients. It is highlighted that the rising demand for dentures, particularly among the elderly, due to factors such as aging populations and associated health issues affecting oral hygiene. Alternatively, new development of antimicrobial elimination that could effectively inhibit the growth of oral bacteria could be an active area of research. The aim of this study is to investigate the antimicrobial interaction of PLA/TTO microcapsules in polymerized PMMA denture base resin against Staphylococcus aureus, Streptococcus mutans and Candida albicans. A new drug delivery methodology employed via emulsion and solvent evaporation (ESE) techniques was performed to synthesize polylactic acid (PLA) microcapsules containing antimicrobial agents; tea tree oil (TTO). The characterization of TTO/PLA microcapsules were characterized using Ultraviolet-visible (UV-Vis), Fourier-transform Infrared (FTIR), Gas chromatography-mass spectrometry (GCMS) and field emission scanning electron microscope (FESEM). The modified PMMA denture base was prepared in three different concentrations of prepared microcapsules (TTO: PLA (% w/w)), 10%, 50% and 100%. For antimicrobial activity, the modified PMMA was evaluated for antimicrobial activity through leaching solution at the intervals of 7th, 14th and 30th days using the well diffusion test and time-killed assay. Then, FESEM images was performed to assess the attachment of microorganism on the surface of modified denture base. The results obtained from characterization analysis showed the microcapsules were successfully synthesized using emulsion and solvent evaporation method where the drug release study and the average particle size formed is homogenously distributed for controlled drug release. The antimicrobial activity of modified PMMA base resin incorporated with PLA/TTO microcapsules showed a good antimicrobial effect (Table 4.2/4.3/4.4/4.5) and statistically revealed a significant effect (p<0.05) against S. aureus and C. albicans where the inhibition area increased as the concentration increased except for S. mutans. The time killed assay was used to study the antimicrobial agent over the time, it showed that the antimicrobial activity of modified denture base exhibited a good antimicrobial effect against all microorganism tested. In morphological test using FESEM, the attachment of fungal and bacteria cell tested is lesser as the concentration increased within 24 hours studied. The study revealed incorporation of PLA/TTO microcapsules in denture base, has significant impacted on enhanced antimicrobial activity, offering potential usefulness for denture users in the future. However, further studies including physical properties and cytotoxicity are needed to be investigated before the clinical trials.
- PublicationAntibacterial, cytotoxic and genotoxic effects of nano-hydroxyapatite-silica glass ionomer cement and its dentine pulp complex response in a rat model(2025-08)Niazi, Fayez HussainThe aim of this study was to assess antibacterial and genotoxic effects of nano-hydroxyapatite-silica glass ionomer cement (nano-HA-SiO2-GIC) and its dentine pulp complex reactions’ evaluation in an animal model. Minimal bacterial concentration (MBC), minimal inhibitory concentration (MIC), and time kill assay (TKA) were carried out to assess antibacterial efficacy for 10% nano-HA-SiO2-GIC and compared with conventional Glass ionomer cement (cGIC) against three different bacteria Streptococcus mutans, Staphylococcus aureus and Enterococcus faecalis. Mutagenicity and DNA damage of nano-HA-SiO2-GIC using Comet assay and Ames test were also evaluated. Further, an in-vivo study was performed to evaluate and compare the dentin–pulp complex response following occlusal and cervical restorations in rat molars restored with nano-HA-SiO2-GIC and cGIC. It was found that both S. aureus and E. faecalis exhibited comparatively greater resistance to cGIC with an MIC of 30μg/mL. In contrast, the MIC of cGIC against S. mutans was 20μg/mL. The MIC for nano-HA-SiO₂-GIC were the same for E. faecalis when compared with cGIC (30μg/mL) whereas it was 10μg/mL for both S. mutans and S. aureus (p < 0.05). Time kill assays revealed that nano-HA-SiO₂-GIC effectively killed 99% of the tested bacteria after 6 hours whereas cGIC was able to eradicate these bacteria in 8 hours. The highest cell viability (159.4%) for nano-HA-SiO2-GIC was noticed at 3.125 mg/ml, while the lowest (24.26%) was observed at 200 mg per ml. IC50, IC25 and IC10 values were 95.27, 51.4 and 20.1 mg/ml for cGIC, and 106.9, 55.8 and 22.9 mg/ml for nano-HA-SiO2-GIC respectively. The IC10 of both test materials showed no significant DNA damage compared to that of the negative control based on the Comet assay (p > 0.05). Despite this, a significant difference was present in the tail moment between all concentrations of both types of GIC groups as well as the positive control (p < 0.05). Nano-HA-SiO2-GIC showed less than double the average number of revertant colonies compared to that of the negative control when tested using Ames test. For in-vivo studies, parameters such as disorganization of the pulp tissue, inflammatory cell infiltration, detection of bacteria, and tertiary dentin deposition were measured for each group. Overall, there was no difference between cervical and occlusal restorations in terms of remaining dentine thickness (RDT). One week after the sacrifice, the odontoblastic layer was disrupted the pulp area close to the cut dentin displayed moderate inflammation in both types of restorations. One month after sacrifice, there was no evidence of disruptions of the odontoblast layer. In terms of inflammation, the pulp tissue recovered in almost all cases except one of c-GIC, but a few cases of the nano-HA-SiO2-GIC group still displayed mild-to-moderate inflammatory reactions, especially on the occlusal restorations. A significant difference in tertiary dentin thickness (TDT) in first molars was observed for both cGIC (66.21 ± 43.15), and nano-HA-SiO2-GIC (96.66 ± 41.2) as compared to second molars (31.97 ± 5.30). The addition of nano-HA-SiO2 to cGIC significantly enhanced the antibacterial properties, found to be non-mutagenic and do not cause DNA damage at the lowest concentration of IC10 based on the Comet assay. In addition, it exerted favourable dentine pulp complex response when compared to cGIC. Based on the findings of the current study, nano-HA-SiO2-GIC produce promising findings and thus can be suggested as a future potential material for use in clinical dentistry
- PublicationElucidating IFI6 and RSAD2 protein expression in oral squamous cell carcinoma using immunohistochemistry and aptahistochemistry with novel in silico DNA-aptamers(2025-07)Butt, Danial QasimEmerging research highlights interferon-stimulated genes (ISGs) such as IFI6 and RSAD2 as potential protumorigenic biomarkers, contributing to cancer proliferation and survival. While their role in apoptotic dysregulation has been documented in various malignancies, their involvement in evading immune evasion, particularly in oral squamous cell carcinoma (OSCC), remains largely unexplored. Understanding their influence within the tumour microenvironment is, therefore, imperative. Advances in biomarker detection technologies offer substantial advantages in improving specificity, sensitivity, and reproducibility while mitigating cost and batch variation challenges in antibody-based OSCC diagnostics. This study aims to examine IFI6 and RSAD2 protein expression in cancer and immune cells (neutrophils, plasma cells, and lymphocytes) within the OSCC tumour microenvironment using immunohistochemistry (IHC) and aptahistochemistry (AHC), employing in silico-derived DNA aptamers. Additionally, it seeks to design, characterise, and validate these DNA aptamers for potential application in AHC. IFI6 and RSAD2 protein expression was analysed in OSCC (n=23) and healthy (n=7) tissue samples via IHC and AHC. The correlation between protein expression, cancer, immune cell presence, and histological tumor grades was statistically assessed. DNA aptamers for IFI6 and RSAD2 were designed in silico, and their binding interactions were characterised using molecular docking (binding energy), PyMOL, and Protein Ligand Interaction Profiler (PLIP) for hydrogen bonding analysis. Molecular dynamics simulations in GROMACS assessed complex stability (RMSD) and aptamer flexibility (RMSF). Stem-hairpin loop DNA aptamers (35–50 meters) were successfully developed for IFI6 and RSAD2. Among them, 35- and 50-mer IFI6 and 35- and 45-mer RSAD2 aptamers exhibited high binding affinity (-15.7 to -18.7 kcal/mol), strong hydrogen bonding (<4 Å), stable RMSD (<0.4 nm), and flexible loop regions (RMSF >0.4 nm). IHC and AHC analyses revealed significant IFI6 and RSAD2 expression in OSCC tissues while absent in healthy samples (p<0.05). Expression levels were markedly elevated in poorly differentiated tumour grades and tumour-associated immune cells (p<0.05). This study confirms IFI6 and RSAD2 expression in OSCC cancer and immune cells, correlating with higher tumour grades. These findings support their potential as prognostic biomarkers in the tumour microenvironment. The in silico-derived DNA aptamers demonstrate strong binding characteristics and hold promise for AHC-based OSCC detection, offering a cost-effective and reliable diagnostic alternative.
- PublicationSynthesis and mechanical properties of a modified low-shrinkage diacrylated polyethylene glycol composite resin(2025-07)Nongman, Abdul FattahThis study investigates the synthesis, characterisation, and application potential of low-shrinkage diacrylated polyethylene glycol (DAPEG)-based (also known as PEGDA – polyethylene glycol diacrylate) dental composites, focusing on the effects of molecular weight and silica filler loading on mechanical, thermal, and dimensional properties. Silica was synthesised via the sol-gel process from tetraethyl orthosilicate (TEOS) was confirmed with Fourier Transform Infrared. DAPEG monomers were synthesised from polyethylene glycol and acryloyl chloride, verified by FTIR and nuclear magnetic resonance, revealing a clear influence of molecular weight on thermal stability. DAPEG 400 with lower molecular weight shows a lower density and viscosity, hence improving the curing behaviour. In addition, DAPEG 400 demonstrated good depth of cure, high degree of conversion, gel content, and also ease of handling compared to higher molecular weight DAPEGs. Higher molecular weight DAPEG 4000 exhibited enhanced crystallinity and thermal stability. DAPEG 400 composites with optimal silica filler loading significantly increased mechanical properties (flexural and compressive strength) up to 10.27 MPa and 41.42 MPa, water resistance, and dimensional stability, plus lower polymerisation shrinkage. In this work, DAPEG 400 composite with 60 % silica loading demonstrated the lowest polymerisation shrinkage of 1.58 %, much lower than other dental composite resins available in the market.