Pusat Pengajian Sains Pergigian - Tesis

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A longitudinal qualitative study on lived experience of oral cancer patients during covid-19 pandemic in khyber pakhtunkhwa Pakistan
(2023-02)
Khattak, Maria Ishaq
Oral cancer health experiences are profound and complex for patients even at the best of times. There is, however, little knowledge of how oral cancer patient’s health experiences may alter and develop in response to the COVID-19 pandemic's changing environment. This study explored the physical, social and psychological experiences of oral cancer patients at diagnosis, six months after diagnosis, and one year after diagnosis, with a particular focus on how experiences change through the different periods of time during the COVID-19 pandemic. Patients diagnosed with oral cancer at Khyber College of Dentistry, Peshawar, Pakistan were included in the study. The participants were selected using a maximum variation purposive sampling method to participate in this study. A longitudinal qualitative design was employed using the principles of phenomenological inquiry. Three semi-structured interviews were conducted as follows: at diagnosis (T1), six months after diagnosis (T2), and twelve months after diagnosis (T3). The sample at T1 and T2 comprised 17 participants. The sample at T3 comprised of a total 12 participants. The interviews were conducted in Pashto, the local language of Khyber Pakhtunkhwa. The audio-recorded interviews were transcribed ad verbatim in English and thematically analyzed. Data was organized using ATLAS.ti software version 8. Eight major broad-level themes were derived at T1: (1) pain and generalized physical weakness, (2) shock at diagnosis, (3) psychological distress of the COVID-19 pandemic, (4) faith and religion, (5) double hit loss of employment, (6) social isolation, (7) social support from caregivers, and (8) lack of support from health care professionals. At T2, five major broad-level themes were derived: (1) physical impairment and limitations, (2) psychological vulnerability, (3) reliance on God for protection, (4) availability of social support systems, and (5) financial decline. Finally, four major broad level themes were derived at T3: (1) the new normal, (2) the sum of fears, (3) belief in traditional healing practices, and (4) striving towards normalcy in social life. In conclusion, this longitudinal qualitative study provides insight into the complexities of living with oral cancer during the pandemic. The narratives in the study highlight conventional physical experiences while heightened psycho-social concerns at diagnosis. Patients social support slightly improved six months after diagnosis, but increased financial burdens, psychological distress, and physical symptoms continued. Finally, after twelve months, patients attempted to recover physically and gain social normalcy, but unwavering psychological concerns about the recurrence of oral cancer and the COVID- 19 pandemic lingered. The duality of the common oral cancer experiences and additional pandemic-inflicted experiences were evident in all three phases which affected the physical, psychological, and social well-being of oral cancer patients in Pakistan
A new regression modelling approach and its application in biostatistics
(2024-07)
Eusufzai, Sumaiya Zabin
This research aims to develop an integrated methodology that will be formulated within a Multilayer Feedforward Neural Network (MLFFNN) framework and logistic regression. The mean absolute deviation and predicted mean square error will be utilised to evaluate the performance of the integrated model, and it serves as a yardstick to determine the accuracy and efficiency of the forecasting that is achieved as a result. The urgency of better significant results serves as a motivation for this study. The objective of this study is to develop and implement an integrated model combining Bootstrap and MLFFNN with logistic regression modelling (LRM) to achieve better prediction accuracy and interpretability. The integrated method used in this study is based on the principles of Bootstrap, LRM, and MLFFNN. The accuracy of the proposed technique is assessed using the Predicted Mean Squared Error Neural Network (PMSE.net), Mean Absolute Deviance (MAD), and the accuracy percentage. Each of these components acts as a benchmark for assessing the precision and effectiveness of the created model. A t-test was used to explore the difference between actual and predicted values from the models. Data analysis was conducted using the R program and SPSS version 26. Two case studies from dental public health have been used to validate this newly developed integrated model, i) dental caries among preschool children, and ii) The case study for oral health knowledge among mothers of preschool children. The incorporation of bootstrapping, MLFFNN, and logistic regression in an integrated approach enhances the accuracy of parameter estimation and addresses the uncertain relationship between dependent and independent variables. In the case study focusing on dental caries among preschool children, the Mean Absolute Deviation (MAD) is 0.0221126 and the Predicted Mean Squared Error (PMSE) is 0.07909. A paired sample t-test reveals no significant difference between the actual and predicted values, with means and standard deviations as follows: Actual (Mean [SD] = 0.30 [0.483]) and Predicted (Mean [SD] = 0.31 [0.373]); df = -0.067(9); p-value > 0.05. In the study concerning oral health knowledge among mothers of preschool children, the MAD is 0.05303337, and the PMSE is 0.053033. Results from the paired sample t-test indicate no significant difference between actual and predicted values, with means and standard deviations as follows: Actual (Mean [SD] = 0.600 [0.940]) and Predicted (Mean [SD] = 0.940 [0.030]); df = -2.154(9). This study’s findings will considerably contribute to epidemiological methodology research, particularly relationship mapping, by introducing an integrated model. Concerning MAD, PMSE, and p-value, these indicate both models showed high accuracy in outcome prediction. The significance of the produced syntax outcome will suggest a more accurate decision-making process in disease prevention.
A study of temporomandibular joint morphology and positions among class i, class ii, class iii malocclusion and the effect of petit facemask in class iii malocclusion subjects
(2022)
Azhar, Mohammed Irfan
The temporomandibular joint (TMJ) is the most complex synovial joint in the body. TMJ morphology can be affected due to various reasons such as age, sex, increased or decreased muscle activity, the growth pattern of the face, pathological changes, occlusal forces, and changes in the dental occlusion. The effect of these changes can result in remodelling and reconfiguration of the TMJ surfaces. Therefore, careful diagnosis and treatment planning is very essential before the initiation of any orthodontic procedure. The purpose of our study was to evaluate and compare the TMJ morphology of 120 subjects with 40 subjects each in Class I, Class II and Class III malocclusion using pre-treatment lateral cephalometric radiographs (LCRs) and to evaluate and compare the TMJ morphology of 28 subjects with Class III malocclusion treated with petit-FM (Facemask) using pre-and post-treatment LCRs. TMJ evaluation included the measurements of porion location (PL), glenoid fossa, condyle position, condylar height (CH), joint spaces, maxillary base position (MX) and mandibular base position (MD). This was a retrospective cross-sectional study. LCRs were obtained using Planmeca Promax 3D machine (Planmeca Oy, Helsinki, Finland). TMJ morphology measurements were accomplished using the WinCeph cephalometric software version.11 (Rise corporation, Sendai, Japan) for both objectives. Data analysis was performed using SPSS ver.26 software (IBM, SPSS Statistics, Armonk, NY-USA). A one-way ANOVA and Bonferroni post hoc test was done for objective 1, while paired t-test was carried out for objective 2. The comparison of TMJ morphology between Class I, II and III malocclusions showed a significant difference for superior joint space (SJS), posterior joint space (PJS), and MD with (p = 0.00). Correspondingly, the comparison of TMJ morphology between pre-and post-treatment subjects of Class III malocclusion in response to petit-FM therapy revealed significant difference for horizontal positions of the glenoid fossa with (p = 0.00) and (p = 0.03) respectively. Significant difference was observed in hinge axis with (p = 0.00) and (p = 0.04) and all variables of condyle position with (p = 0.00). Lastly, all the joint spaces, MX, and MD showed statistically significant differences with (p = 0.00). In conclusion, the first objective revealed highest SJS and PJS for Class III malocclusion and lowest for Class II malocclusion respectively. There was increase in the length of mandibular base (MD) in Class III subjects which indicate forwardly placed mandible and decrease in Class II subjects which represent backwardly placed mandible. Correspondingly, the second objective demonstrated significant alterations in horizontal position of the glenoid fossa indicating posterior displacement after FM therapy. The hinge axis and condylar head (both superior and posterior condyle) were placed postero-superiorly, while the anterior condyle was placed postero-inferiorly suggesting clockwise rotation of the mandible post treatment. There was an increase in the length of maxillary base which indicate forwardly placed maxilla and decrease in the length of mandibular base which exhibit backwardly placed mandible. Among joint spaces, the anterior joint space (AJS) was found to be larger, and smaller for SJS and PJS post treatment suggesting upward and backward movement of the mandible.
Alternative method to develop new strategy in ordinal regression: a case study in dental
(2025-03)
Lazin, Muhamamd Amirul Mat
Clinical data usually contain numerous features with a small sample size, resulting in higher dimensionality and poor accuracy. This reduces the performance of classifier systems in high-dimensional data sets because irrelevant features contribute to poor classification accuracy and add extra difficulties in finding potentially useful knowledge. The main objective is to develop an alternative model for ordinal regression through statistical methodology building. The methodology includes a computational study design and statistical techniques customised for dental science modelling. A combination of ordinal regression and bootstrap techniques in the developing an alternative model is the main key to the research focal point. Two case studies, tooth wear severity and tooth sensitivity, were used to test this technique, demonstrating its relevance to real-world dental data. All the fundamental programming was performed using R software. The results show that the alternative approach, especially with more bootstrap replications, offers improved model fitting and precision compared to traditional ordinal regression. This suggests its usefulness in improving the accuracy of health science research, especially in situations with small sample sizes. This study strengthens statistical methods in dental sciences by introducing a more robust alternative to ordinal regression, enabling researchers to obtain more accurate and reliable results even with limited datasets.
Antibacterial, 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 Hussain
The 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
Antimicrobial effects on streptococcus mutans and candida albicans and cytotoxicity study on human periodontal ligament fibroblast cell line of oxy-ionic solution at various ph levels - an in vitro study
(2025-04)
Ming, Xu
Oxy-ionic solutions, comprising hypochlorous acid, sodium hydroxide, and active chlorine, have gained recognition in dental care for their strong antimicrobial properties, especially against pathogens like Streptococcus mutans and Candida albicans. These solutions are produced through the electrolysis of saline water. However, the influence of pH on their antimicrobial effectiveness and cytotoxicity remains uncertain. This study investigates the antimicrobial efficacy of oxy-ionic solutions at varying pH levels (3, 5, and 7) against Streptococcus mutans and Candida albicans and their cytotoxicity on human periodontal ligament fibroblasts. This study evaluated the antimicrobial efficacy and cytotoxicity of oxy-ionic solutions using three complementary approaches. First, disk diffusion and broth microdilution assays quantified antimicrobial effects. Second, scanning electron microscopy (SEM) revealed microbial morphological changes. Third, ATP assays determined cytotoxicity against human periodontal ligament fibroblasts. The oxy-ionic solutions were tested at pH 3, 5, and 7 with concentrations of 100%, 75%, and 25%, except for pH 7 which was assessed only at 100% concentration. Disk diffusion results revealed that the pH 5 solution exhibited the largest zones of growth inhibition, with diameters of 13.79 mm for Streptococcus mutans and 19.67 mm for Candida albicans, indicating the strongest antimicrobial efficacy among the tested pH levels. Broth microdilution assays further confirmed this, with the pH 5 solution demonstrating the minimum inhibitory concentration of 50% for Streptococcus mutans and 25% for Candida albicans. Scanning electron microscopy analysis showed significant microbial cell wall damage and morphological changes when treated with the pH 5 solution. The ATP assay results on human periodontal ligament fibroblasts showed that all concentrations of oxy-ionic solutions at pH 3, pH 5, and pH 7 exhibited significant cytotoxicity after 2 minutes of exposure. Although cell viability improved with extended exposure time to 24 hours, it still remained below safe thresholds. These findings suggest that there is a therapeutic potential in the dental care of oxy-ionic solution pH 5 based on high antimicrobial effects, however further study on the dilution of the solution is necessary to ensure clinical safety and effectiveness.
Assessment of inflammatory markers and periodontal outcomes in CKD patients with periodontitis
(2022-06)
Rahman, Nurul Aliya Abdul
Chronic kidney disease (CKD) and periodontitis have an impact on patient’s morbidity and mortality. The prevalence of comorbid CKD and periodontitis is shown to be frequent. Periodontitis increases the inflammatory burden, which has been shown to disrupt renal function by altering serum inflammatory levels, and potentially worsening CKD. Pro-inflammatory Interleukin-1 (IL-1) and anti-inflammatory Interleukin-10 (IL-10) have immunomodulatory properties that regulates host immune responses. Little is known about changes in the serum inflammatory markers of IL-1 and IL-10 following the periodontal therapy in CKD patients in our populations. Therefore, this study was aimed to assess and compare the levels of inflammatory markers IL-1 and IL-10 as well as periodontal parameters at baseline and after receiving NSPT. Twenty CKD patients (stage 3 and stage 4) with periodontitis (Group 1), twenty non-CKD patients with periodontitis (Group 2) and twenty healthy patients (Group 3) were selected. The dental parameters such as Periodontal Probing Depth (PPD), Clinical Attachment Loss (CAL), Gingival Bleeding Index (GI) and Plaque Score (PS) were measured in each patient during first visit (baseline) and six weeks later (second visit). Blood sample was collected during each visit and analysed for serum IL-1 and IL-10 concentration using Enzyme-Linked Immunosorbent Assay. Our findings shows that IL-1 and IL-10 levels were found significantly higher (p<0.05) in CKD patients with periodontitis (Group 1) as compared to non-CKD patients with periodontitis (Group 2) and healthy subjects (Group 3). When compared to other groups, the levels of dental parameters (PPD, PS and GBI in Group 1 were significantly higher (p<0.05). Following NSPT, there was significant reduction (p<0.05) in inflammatory markers and clinical periodontal parameters in Group 1 and Group 2. This study demonstrates that patients with CKD and periodontitis had a more severe systemic inflammatory response and poorer periodontal status than non-CKD. NSPT shown improvement in both inflammatory markers and dental parameters as well as delay the progression of CKD. IL-1 and IL-10 is a promising inflammatory marker to assess CKD progression. Therefore, multicentre and larger sample size studies are needed in the future.
Bacterial leakage and marginal adaptation of three bioceramics pulp dressing material
(2023-04)
Siddiqua, Snigdha Niher Tabassum
This study aims to evaluate the sealing ability and marginal adaptation of three different bioceramics pulp dressing materials using a bacterial leakage test and scanning electron microscope (SEM). Fifty-five recently extracted lower first premolars were randomly divided into five groups, with three experimental groups (n=15), a positive control group (n=5) and a negative control group (n=5). The samples were instrumented with a modified coronal pulpotomy procedure except for the negative control group (n=5). Different types of bioceramics dressing material were placed in the cavity 3mm thickness in group 1 (Biodentine), group 2 (MTA) and group 3 (ProRoot MTA). There was no dressing material placed in the positive control group. Samples were placed in an incubator at 37℃, 100% humidity, for 24 hours to allow the material to be set, after the placement of the composite restoration. Two layers of nail varnish were applied, and the 3mm root tip was removed. The bacterial leakage test was performed using Enterococcus faecalis, and one sample from each experimental group was sliced and examined under SEM for marginal adaptation. Data analysis was conducted under the One-way ANOVA test, completed by Tukey’s post hoc test. The groups observed a significant difference in sealing ability and marginal adaptation (p<0.05), wherein Biodentine showed bacterial leakage on day 6 (7%), and on day 14 (80%), MTA showed on day 9 (14%) and on day 14 (40%), ProRoot showed on day 11 (7%) and on day 14 (33%). From SEM, ProRoot MTA demonstrated the least gap between the dressing material and significantly higher penetration in dentinal tubules. ProRoot MTA demonstrated better sealing ability and marginal adaptation compared to other groups. The finding indicates that ProRoot MTA would be the best pulp dressing material for the clinical setting. Keywords: Bacterial leakage test, bioceramics, Biodentine, MTA, ProRoot MTA, Pulpotomy, SEM.
Characterization of fiber reinforced nanohybrid dental composites from agricultural biowaste using kenaf fiber
(2022-06)
Abbas, Hina
Background: Fiber reinforced composite was introduced due to development of new biomaterials, technological advancements, and more effective treatment approaches. Aims of the study: This study aimed to determine the bonding mechanism between kenaf fibers and nanohybrid dental composite derived from agricultural biowaste. The kenaf fiber reinforced composite was investigated for flexural and compressive strength. The features of fractured surface of the flexural specimens were also assessed. Materials and method: Preparation of kenaf fiber reinforced composite was done using the treated silica from rice husk and kenaf cellulose. The kenaf cellulose was processed and treated using tetraethyl orthosilicate (TEOS) sol gel. Fourier- transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to investigate the treated kenaf cellulose. Six specimens were prepared for each group; composite groups A, B, C, D, E, F, G with 0%, 1% untreated, 2% untreated, 1% treated, 2% treated kenaf cellulose, Neofil and ever-X composite respectively. For compressive and flexural strength tests, specimens were formed using stainless steel molds with dimensions of 6mm x 4mm and 25mm x 2mm x 2mm, respectively. After light curing using a light cure unit (Elipar Deep cure L, 3M, USA) for 40 seconds, the specimens were tested using an Instron Universal Testing Machine (Shimadzu, Japan). SEM was used to examine the fractured flexural strength samples. Results: SEM showed the average diameter of treated kenaf fibers was 7.4μm whereas the average length of treated kenaf fibers was 537μm. The FTIR results suggested formation of chemical bonds between the kenaf cellulose and silica from TEOS sol gel. For flexural and compressive strength tests, one way ANOVA showed there was statistically significant difference (P<0.05) between all groups. The nanohybrid composite incorporated with treated kenaf cellulose resulted in comparable compressive strength with the commercial Neofil composite and no improvement for flexural strength. SEM analysis showed smoother fiber surface with presence of lesser voids and gaps between matrix and kenaf fiber which suggested enhanced interfacial bonding. Conclusion: Surface treatment of the kenaf cellulose improved the bonding mechanism in the kenaf reinforced nanohybrid composite. Adaptation between surface treated kenaf fiber and composite matrix contributed to improvement in compressive strength of fiber reinforced composite.
Childrens’ behaviour and physiological parameters at recovery following dental general anaesthesia with and without premedication oral midazolam at Hospital Universiti Sains Malaysia: a preliminary study
(2023-08)
Hisham, Abdul Rauf Badrul
Oral midazolam premedication usually prescribed for controlling behaviour and reducing anxiety of children and the use under general anaesthesia (DGA) on the behavioural and physiological status of uncooperative paediatric patients have not yet been well explored. This study is aimed to evaluate the effect of oral midazolam premedication on recovery behaviour and physiologic parameters of children undergoing DGA. Thirty uncooperative children aged from 2–11 years were involved in this randomised control trial study. Group I: Received 0.5 mg/kg midazolam orally 30 minutes before entering the operation theatre, while Group II: Did not receive any premedication. Their physiologic parameters were measured at the post anaesthesia care unit (PACU). The recovery behaviour was also recorded for the evaluation using the Modified Houpt Behavior Rating Scale. There was no significant differences in all recovery behaviour and physiologic parameters for both groups (p>0.05). No significant association of premedication oral midazolam with successful recovery behaviour (p=0.381). However, an interesting trend of positive recovery behaviour and physiology was observed among children with oral midazolam premedication. More studies with larger sample size are needed to explore the effect of oral midazolam in paediatric DGA as to discover the optimum effect of premedication.
Development and characterisation of kenafnanohybrid dental composites
(2024-02)
Rasid, Noorasyikin Ab
Natural fibres such as kenaf fibres have enormous potential in replacing synthetic fibre used for composite reinforcement. This study aimed to optimize the bonding mechanism between kenaf and nanohybrid dental composite from rice husk and investigate mechanical properties of this composite. Kenaf fibres was processed to obtain cellulose nanocrystals (CNC) and silane treated with hybridization of tetraethyl orthosilicate (TEOS) sol gel and γ-Methacryloxypropyltrimethoxysilane (γ- MPS). The treated CNC was investigated through Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Six specimens from each group with different ratio of γ-MPS and TEOS were prepared for compressive and flexural investigation. The experimental composites were compared with commercial nanohybrid composite and fibre reinforced composite (Ever-X posterior, Filtek Z350 and Neofil). Data was statistically analysed using one-way ANOVA test and the fracture surfaces of the samples were subjected to scanning electron microscope (SEM) assessment. FTIR results showed formation of chemical bonds between kenaf CNC with γ-MPS and TEOS sol gel. TGA showed highest decomposition temperature in non-silane treated kenaf fibre compared to silane treated kenaf fibre. Mean flexural and compressive strength between all groups showed statistically significant results (p=0.000). Experimental composite group with fibre reinforced showing higher flexural strength by 31 % while compressive strength increases by 38% compared to non- fibre reinforced composite, however the strength was lower as compared to commercial composites. The compressive strength of all the experimental composites were significantly lower than that of commercial composites. Silane treatment showing evidence of modification and improved bonding between the kenaf fibres and the resin matrix, even though the strength was lower than the commercial composite.
Development and characterization of honey-plga microparticles with antibacterial properties against streptococcus mutans in oral disease
(2023-08)
Imm, Chu Liu
Application of honey in a certain area of the human body like in the oral cavity might pose a problem due to its liquidity. Thus, honey also has been explored to be used in other forms for suitable application. One form of drug delivery system is through the incorporation of drugs into microparticles. Therefore, the aim of this study is to investigate the potential of honey to be incorporated into microparticles to enhance antibacterial activity. Three types of honey were used; Kelulut, Tualang and Manuka. Honey-PLGA microparticles were prepared using the double emulsion solvent evaporation method. Then the honey-PLGA microparticles were subjected to a variety of analyses and tests, including GC-MS analysis, FESEM, zetasizer analysis, in vitro release and an antibacterial test. Streptococcus mutans was used for antibacterial testing because this bacterium causes caries and periodontitis. The results showed that all types of honey used in this study could be incorporated into microparticles as a white powder. Based on FESEM analysis, honey-PLGA microparticles were spherical, and had a smooth surface, with a diameter ranging from 1 to 10 micrometer. GC-MS analysis showed the identified compounds found in raw Kelulut honey microparticles (RKHMP), raw Manuka honey microparticles (RMHMP) and raw Tualang honey microparticles (RTHMP) were 1, 11 and 5 compounds, respectively. The identified compounds found in extracted Kelulut honey microparticles (EKHMP), extracted Manuka honey microparticles (EMHMP) and extracted Tualang honey microparticles (ETHMP) were 15, 12 and 26 compounds, respectively. Extracted honey microparticles contain more identified compounds compared to raw honey microparticles. Zetasizer analysis showed the microparticles had low zeta potential and thus tended to precipitate in suspension. The microparticles showed slow-release character but no antibacterial activity against Streptococcus mutans. Within the limitation of the study, it can be concluded that, the three types of honey can be incorporated with other materials to produce honey-PLGA microparticles, however further study is needed in term of improving the formulation to produce microparticles that are highly effective against target microorganisms.
Development of a new hybrid model and its application in biostatistics
(2024-09)
Farooqi, Faraz Ahmed
Linear regression, a fundamental tool in statistical analysis, enables the exploration of relationships between variables. Despite its widespread use, traditional regression analysis encounters challenges when handling qualitative predictive variables (QPV), Multilayer Layer Feedforward Neural Network (MLFFNN), and Fuzzy Linear Regression. There is a significant gap in understanding how to integrate multiple linear regression with other approaches to enhance model accuracy and predictability. This highlights the need for the development of hybrid models. Integrating Multiple Linear Regression (MLR) with advanced techniques, such as fuzzy regression and neural networks, addresses MLR's limitations in handling complex data and improves model accuracy and generalizability. This hybrid approach is crucial for overcoming challenges in biostatistics and enhancing predictive performance. This study utilizes a comprehensive methodology that integrates several techniques, such as transforming QPV, bootstrapping, MLFFNN, and employing fuzzy regression. The utility of the developed methodology is demonstrated using three secondary datasets. All obtained results demonstrate statistical significance, with high accuracy reflected in the R2 values. Additionally, small mean squared errors confirm a close alignment between predicted and actual values. All cases show the method's superiority, offering researchers precise tools for biostatistical inferences and forecasts. Future work will adapt this approach for other regression types and explore its application across various domains.
Development of a novel bioceramic root canal sealer and its effect on the dislodgement resistance and dentinal tubule penetration
(2023-06)
Lin, Galvin Sim Siang
The present study aimed to fabricate and characterise novel algin-incorporated bioactive glass 58S calcium-silicate root canal sealer (Bio-G) and evaluate its effect on the dislodgement resistance and dentinal tubule penetration to root dentinal walls in comparison to commercially available bioceramic-based sealers (BioRoot RCS and iRoot SP). Three groups of bioactive glass (BG) 58S powders were synthesised using sol-gel method and characterised using SEM, HRTEM and FTIR for optimisation: BG-1 (no ammonia), BG-2 (3 ml of ammonia), and BG-3 (5 ml of ammonia). Optimised BG-3 was used to fabricate the powder form of experimental Bio-G sealer with the addition of calcium silicate, zirconia dioxide, calcium carbonate and alginic acid powder. Meanwhile, the liquid form composed of 5% calcium chloride solution. The experimental 0-5% algin Bio-G sealers were then compared with BioRoot RCS and iRoot SP. Standardised disc specimens of mixed sealer materials (n=5 per group) were prepared and placed in an incubator to allow setting before characterising under SEM, HRTEM, EDS, FTIR and XRD. Next, one-hundred-and-seventy-six mandibular premolars were randomly assigned (n=16 per group): control, gutta-percha + 0-5% algin Bio-G, gutta-percha + BioRoot RCS, and gutta-percha + iRoot SP groups, with the exclusion of the control group in adhesive pattern and dentinal tubule penetration tests. They were instrumented, obturated and placed in an incubator for 72 hours to allow sealer set. For the dentinal tubule penetration test, sealers were mixed with 0.1% of rhodamine B dye. Subsequently, teeth were cut into a 1-mm-thick cross-section at 5-mm and 10-mm levels from the root apex, respectively. Push-out bond strength, adhesive pattern and dentinal tubule penetration tests were performed. Experimental Bio-G sealer revealed irregular micro-sized particles with a higher content of oxygen, silicon, and calcium, as well as trace of aluminium and chloride. Meanwhile, FTIR and XRD findings suggested that all sealers predominantly contained calcium silicate hydrate, calcium carbonate, and zirconium dioxide, while calcium aluminium silicate oxide was detected in 0-5% algin Bio-G. 5% algin Bio-G showed the highest mean push-out bond strength (p<0.05) with more favourable adhesion pattern, while iRoot SP showed the greatest sealer penetration (p<0.05). In addition, no significant association was noted between the dislodgement resistance and dentinal tubule penetration (p>0.05). In conclusion, the present novel Bio-G sealer demonstrated desirable particle size distribution and acceptable degree of purity. Algin-incorporated Bio-G showed favourable adhesive pattern with comparable dislodgement resistance and dentinal tubule penetration values to commercialised bioceramic-based sealers.
Effect of low-level laser therapy on stability during retention phase after orhodontic treatment: a randomized controlled trial
(2025-03)
Yanpei, Wang
Low-level laser, also known as weak laser and low-intensity laser normally produce stimulating or positive effects on alveolar bone remodeling, inducing an increase osteoblasts and osteoclast resulting increased the incidence of orthodontic tooth movement (OTM) and inhibitory effects depending on the dose. The aim of this study is to investigate the stability in maxillary dentition after application of low-level laser therapy (LLLT) during leveling and alignment stage of fixed appliances. In this experiment, 20 eligible participants were selected from the random sampling samples of the previous experiments, and the Little's Irregularity Index (LII), intermolar width (IMW), intercanine width (ICW), arch length (AL), overbite(OB), and overjet(OJ) of the maxillary dentition were measured according to the ratio of the laser group: control group = 1;1. The results of the measurements were analyzed by SPSS version 26. Friedman's test and repeated-measures ANOVA were used for statistical comparison. The results of LII, ICW, OB, and OJ were not significant (P > 0.05). However, IMW (P = 0.038) and AL (P = 0.019) was statistically significant. Although the overall effects of LII, ICW, OB and OJ were not significant, the mean values in the laser group were generally smaller compared to control group. LLLT has no significant effects on LII, ICW, OB, and OJ. It was concluded that LLLT only had a subsequent effect on IMW and AL during 12 months of retention period. However, within group changes, LLLT has smaller mean values which indicate the stability over time in the laser group was clearly better than control group to prevent relapse.
Effects of single dose low-level laser therapy, on pain and healing of extraction socket after extraction of premolars in orthodontic patients
(2023-09)
Karim, Meenaz
Tooth extraction for orthodontic purposes is a common procedure. However, extractions, just like other surgeries carry some complications and risk like pain, swelling, infections, and dry socket. Non-steroidal anti-inflammatory drugs (NSAIDs) are preferred medicines to reduce post-extraction pain, but it may have systemic effects. Low-level laser therapy (LLLT) has been found effective in decreasing the post-extraction pain and acceleration of wound healing after third-molar extraction. Orthodontic forces initiate osteoclastic activities in the alveolar bone which causes mobility of the tooth which also eases the extraction and reduces post-extraction pain, but it has not been investigated. The purpose of this research was to evaluate the effect of single dose of LLLT on the pain and healing of extraction socket before alignment and levelling stage, after initiation of orthodontic treatment. Forty-four Pakistani patients, age between 12 to 18 years who needed pre-molar extraction for orthodontic treatment were selected, which were then divided into 2 groups (A and B). Both groups had experimental (Ae, Be) and placebo sides (Ap, Bp), allocated randomly for split mouth design. Group A underwent extractions first, then orthodontic treatment. However, group B underwent extractions after alignment and leveling of teeth. Gallium-Aluminum- Arsenic diode laser (continuous-mode, wavelength 940nm) was applied on 6points buccally and palatally, 1cm apical to the extraction socket, immediately after extraction. Irradiation was applied for 30seconds at each point, emitting energy of 3joules. After extraction, pain was recorded for a week with numeric rating scale and wound healing was assessed clinically at baseline, 2nd, 7th and 15th day. SPSS version 22.0 was used to analyze the data. Experimental and placebo sides were compared to observe the effect of LLLT on pain and wound healing, while inter group comparison was made to see the effects of prior engagement of tooth with the arch-wire, on pain and wound healing. Non-parametric Mann Whitney U test and Krusker Wallis test were applied to compare the results amongst all the groups. Group A experienced significantly more pain when compared with group B (p<0.05). The difference in pain between experimental and placebo sides in both the groups was insignificant. No significant difference was observed regarding wound healing among groups. In conclusion, single visit application of LLLT did not reduce the post-extraction pain and did not affect the extraction wound healing in orthodontic patients. Prior engagement of pre-molars reduced the extraction pain, however wound healing remained unaffected.
Elucidating IFI6 and RSAD2 protein expression in oral squamous cell carcinoma using immunohistochemistry and aptahistochemistry with novel in silico DNA-aptamers
(2025-07)
Butt, Danial Qasim
Emerging 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.
Evaluation of bacterial colonization on titanium dental implant surfaces following different instrumentation techniques: a comparative study
(2025-03)
Ghaffar, Hareem
The use of various hygiene tools for implant maintenance affects surface configurations, which in turn affects bacterial adhesion on titanium implant surfaces, which can lead to peri-implant diseases. This study aimed to compare the surface topographies and Streptococcus sanguinis colonization on titanium implant fixture surfaces after polishing methods with Er, Cr: YSGG laser, airflow, and titanium brush group with control/untreated group using Scanning Electron Microscope (SEM) observation and Colony Forming Unit (CFU) counts. Twenty MegaGen titanium implant fixtures were randomly distributed into four groups. Five fixtures were randomly selected for the control/untreated (C) group while the other three groups were treated with Er, Cr: YSGG laser, airflow, and titanium brush. One fixture from each group was observed under SEM for surface topographies evaluation. All other samples were cultured with Streptococcus sanguinis for bacterial colonization and adhesion evaluation. One sample for each group was selected for SEM observation while the other samples were prepared for CFU counting. From the SEM analysis, the surface topography produced by the titanium brush showed a smooth surface followed by airflow with fewer surface irregularities, and the laser group showed a haphazard structure as compared to the control group. Similarly, for bacterial colonization, the titanium brush had the least bacterial cell growth, sparsely present on the surface same as the control group followed by the airflow group showed the multilayer chains of colonies, and the laser group showed the clusters of colonies. However, for the CFU result, statistical analysis revealed a significant value (p<0.05) among all four groups. Titanium brush was concluded as the least invasive and most effective instrumentation tool for implant fixture surface topographies and bacterial growth evaluated under SEM. However, from CFU counts, the airflow instrumentation was found to be the one having the least bacterial counts compared to other groups
Expression of inhibitory neurotransmitter gabaa receptors in human dental pulp: a potential role in dental nociceptive signalling
(2023-08)
Sivakumar, Diveyaa
Dental pain is a prevalent and distressing condition that can have a significant impact on a person's daily life. It can arise from various causes, including dental diseases and conditions, as well as during dental treatments. Development of effective pain management strategies in the dental setting remains a challenge due to the unclear mechanisms of pain signalling in the dental pulp. Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian central nervous system (CNS) and has a well-established role in pain signalling. While several studies have explored the expression GABA and its receptors in the dental pulp, the exact influence of these receptors on dental pain signalling is still not fully understood. Therefore, this study aimed to investigate the gene and protein expression of the two most abundantly expressed GABAA receptor subunits, α1 and β2, in the healthy human dental pulp. In order to achieve the objective of the study, techniques such as RNA isolation, reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were employed. Prior to performing RT-PCR, the annealing temperature for amplification of both target genes were found to be 55°C. Gene expression analysis using RT-PCR demonstrated the presence of GABRA1 and GABRB2 in the dental pulp, and independent T-test analysis indicated that the expression of GABRA1 was significantly higher than GABRB2. Immunohistochemical staining provided visual evidence of GABRA1 and GABRB2 protein expression in the odontoblast layer of dental pulp, indicating their presence in cell bodies and odontoblastic processes extending into the dentin. Optimal IHC staining results were obtained by using Tris- EDTA (TE) buffer at pH9 for antigen retrieval with antibody concentrations of 1:50 and 1:200 for the GABRA1 and GABRB2 antibodies, respectively. These findings support the hypothesis that GABAA receptor α1 and β2 subunits are expressed in human dental pulp. The presence of gene and protein expression of these subunits offers valuable insights for further research into the potential roles of GABAA receptors in dental related pain signalling. Future studies using diseased samples and functional investigations are warranted to explore the precise mechanisms and implications of GABAA receptor α1 and β2 subunits in dental pain and their potential therapeutic applications.
Expression of vascular endothelial growth receptors in human papilloma virus-related oral squamous cell carcinoma cell lines
(2024-09)
Aziz, Muhammad Zulhilmi Ab
Oral squamous cell carcinoma (OSCC) is the most common type of malignancy that arises from mucosal epithelial lining of oral cavity. Smoking tobacco, alcohol consumption and Human Papillomavirus (HPV) are the main risk factors for OSCC. However, the effect of HPV infection in OSCC towards Vascular Endothelial Growth Factor Receptor (VEGFR) signalling in OSCC development is still unclear. This study aims to determine the expression of VEGFR1, VEGFR2, phosphorylated VEGFR1 (pVEGFR1), phosphorylated VEGFR2 (pVEGFR2) and Ki-67 with regards to HPV status in OSCC cell lines. Two types of OSCC cell lines which are HSC-2 (HPV-negative) and UPCI:SCC154 (HPV-positive) were maintained according to their recommended conditions. The expression of VEGFR1, VEGFR2, pVEGFR1, pVEGFR2 and Ki-67 were analysed using flow cytometry. The expression of VEGFR2 and pVEGFR2 were significantly higher on HSC-2 cells while significantly higher expression of Ki-67 was shown on SCC154 cells. Nevertheless, the protein expression value for all the targeted markers was higher on HSC-2 cells but not for Ki-67 which was higher on SCC154 cells. As conclusion, this study revealed that HPV infection in OSCC decreased the VEGFR expression which resulted in lower angiogenesis activity in HPV-infected OSCC. High Ki-67 expression in HPV-infected OSCC suggested that cell proliferation activity in HPV-infected OSCC was high even though lower angiogenesis marker were presented.

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