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 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.
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 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.
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.
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.
Fracture Resistance Of Weakened Root Structure Reinforced With Two Types Of Composite Resin And Endodontic Sealer
(2009-02)
Ahmad Mahmood Ahmad
The aim of this study was to compare the fracture resistance of weakened roots obturated with a new nano HA endodontic sealer or an epoxy resin endodontic sealer and reinforced by either auto-cured or light-cured composite resin.
Inhibition of endoplasmic reticulum stress using 4-phenyl butyrate mitigates osteoporosis in a mouse model of hindlimb suspension
(2024-08)
Al-Daghestani, Hiba Saad Subhi
Osteoporosis (OP) characterized by micro-architectural deterioration of bone tissue is a common skeletal disease in the elderly and may lead to fragility fractures. It may also negatively affect implant rehabilitation and prosthesis fixation in the older people. Mouse hindlimb suspension (HLS) is an established model to study disuse- induced OP and its molecular pathology. The disruption of protein folding by endoplasmic reticulum (ER), called ER stress may be a prime driver of OP during disuse. 4- phenylbutyrate (4-PBA) is short chain fatty acid that functions as a chemical chaperone to reduce ER stress. We aimed to investigate the impact of ER stress on OP, and the effect of 4-PBA, as an ER stress inhibitor in the HLS mouse with OP. 21 male C57BL/6J mice were randomly divided into three groups namely: ground-based controls, untreated HLS group, and HLS treated with 4-PBA via intra-peritoneal injections at 100mg/kg/d for 21 days. HLS duration was for 21 days, thereafter, mice were euthanized by cervical dislocation. Humeri, femora, and tibiae bones were collected and cleaned from soft tissues for measurements of reactive oxygen species (ROS) levels, histomorphometry, micro-CT, Raman spectroscopy, and gene expression studies. The results obtained were analysed using GraphPad Prism version 8. High levels of ROS were generated in the hindlimbs (HLs) and forelimbs (FLs) of the untreated HLS group compared to controls. The tibiae bones of the untreated HLS group demonstrated lower osteocyte density, numerous multinucleated osteoclast-like cells, and adipocyte infiltration within the marrow, while micro-CT revealed lower bone volume fraction, reduced trabecular thickness, along with fewer trabeculae striations with increased trabecular separation. Cortical thickness and total cross-section of cortical area were also reduced. Raman spectrophotometric analysis of the femur in the untreated HLS group revealed elevated ER stress with an increase in levels of hydroxyproline, non-collagenous proteins, phenylalanine, tyrosine, and CH2Wag, and a reduction in proteoglycans and adenine. Alkaline phosphatase (ALP) and osteocalcin (OC) expressions were downregulated, while cathepsin K (Cat K), Tartrate resistant Acid Phosphatase (TRAP), and sclerostin were upregulated. Taken together, these characteristics of bone reflect poorer mineralization, less collagen crosslinking, and a pro-inflammatory effect. Treatment with 4-PBA mitigated ER stress levels, restored the normal bone histomorphometry and microarchitecture, increased collagen crosslinking and mineralization, and promoted anti-inflammatory and downregulated bone resorption markers. This study shed light on characterizing the potential contribution of ER stress to OP during bone disuse and the potential effect of 4-PBA as an innovative pharmacological approach to OP treatment.
Investigation of chemicomechanical properties of polyamide 12 composite reinforced with fillers from agriculture biowaste as a potential dental post
(2024-04)
Babu, Nurul Syafika Atikah
Nanofillers and short fibres were added to polymer composites as the reinforcements to improve their mechanical properties. The synthetic E-glass fibres used in fibre- reinforced composite of commercial dental post was reported to be hazardous. Oil palm fibres and rice husk silica are cheaper and generally safer for workers than glass fibres in composite production. The aim of this research is to produce dental post and core which incorporated natural oil palm fibre (OPF) and rice husk (RH) silica from agricultural waste into the matrix and also to investigate the chemicomechanical properties of the produced post compared to the commercial post. Preparation of OPF/RH Silica/PA12 reinforced nanocomposite post was done by incorporating treated silica from rice husk and oil palm fibre crystallized nanocellulose (OPF CNC) into Polyamide 12 (PA12) matrix. Six samples with a size of 1.5mm x 2.0mm x 25.0mm were prepared for 7 groups (n=6, N=42) and six samples with the size 4mm diameter x 6mm height, were also prepared for 7 groups (n=6, N=42); Group 1 100% PA12, Group 2 PA12 (99%) + OPF CNC (1%), Group 3 PA12 (98%) + OPF CNC (2%), Group 4 PA12 (80%) + (20%) RH silica, Group 5 PA12 (80%) +(19%) RH silica + (1%) OPF CNC, Group 6 PA12 (80%) +(18%) RH silica + (2%) OPF CNC, Group 7 everStick post (flexure test)/ everX FlowTM (compressive test). The flexure and compressive tests were carried out using Instron Universal Testing Machine (Shimadzu, Japan) and the data were analysed using IBM SPSS version 26.0 (SPSS Inc, Chicago, IL, USA). Fourier- transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Thermogravimetric analysis (TGA) were used to examine the fractured flexural strength samples. Flexural test showed that there was a statistically significant difference in flexural strength between different groups (χ2 (df) = 38.65 (6), whereby the PA12 with CNC fillers showed an increased in flexure strength value compared to unfilled PA12 and has no significant difference with commercial post. The incorporation of OPF CNC in the PA12 composite however did not increase the compressive value compared to unfilled PA12 and showed a significantly reduction in compressive strength compared to commercial composite. SEM analysis confirmed the presence of both fillers in the composite and showed smoother surface with presence of lesser voids and gaps with increment of filler wt% which suggested enhanced interfacial bonding. TGA analysis showed that OPF CNC lowered the thermostability of the composite while RH silica improved the thermostability of the composite. Incorporation of OPF CNC into PA12 matrix increased flexure strength of the composite. Incorporation of silica on the other hand reduced the flexure strength of PA12. However, the incorporation of OPF CNC or RH silica did not give any impact to the compressive strength of PA12.
Investigation of skeletal relationships, tooth abnormalities, and biochemical composition of saliva in cleft lip and palate patients
(2023-09)
Qadeer, Mustafa
Cleft lip and palate (CLP) that affects many neonates annually, is one of the most common birth deformities and has been found to be linked with various other orofacial abnormalities including dental enamel hypoplasia and skeletal defects. Several studies have investigated some dental anomalies associated with CLP patients. However, details of the internal tooth structure (enamel thickness, enamel density and dentine thickness) as well as biochemical composition of saliva in patients with CLP are not available. The overall goal of this study is to assess skeletal relationships, tooth structures, tooth size and biochemical composition of the saliva in patients with CLP. A retrospective record review was conducted in the Department of Orthodontics and Oral Radiology, CMH-Lahore Medical College and Institute of Dentistry. 4152 cone beam computed tomography (CBCT) data sorting was performed and 73 patients with cleft were included to identify skeletal relationships in different cleft-types. Meanwhile, 84 ‘non-syndromic’ CLP patients (41 unilateral cleft lip and palate (UCLP) and 43 bilateral cleft lip and palate (BCLP)) and 39 non cleft subjects were selected to identify tooth abnormalities. Enamel thickness, enamel density, dentin thickness, and tooth size of the permanent maxillary incisors and canines were measured from their CBCT scans. Two-way ANOVA with interaction effect was applied to examine if gender has an effect in addition to cleft on various measurements of teeth. A cross-sectional study was conducted where saliva samples were collected from 27 individuals with UCLP, 27 individuals with BCLP, and 27 non-cleft individuals. Precipitate and supernatant of this saliva samples were analised by using fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy/energy-dispersive X-ray (SEM/EDX). Results of the skeletal relationships showed that the skeletal class III were found to be predominant in both sexes, followed by class II and class I (p ˃ 0.05). For tooth abnormalities, the enamel thickness, enamel density, mesiodistal width, crown height, root length and tooth length were significantly smaller in patients with CLP compared to non-cleft individuals (p < 0.05) while dentine showed no significant difference in most of teeth measured (p ˃ 0.05). Missing lateral incisor (81.4%) was found to be more common in BCLP. Atypical root shape was more prevalent in right lateral incisor in BCLP (p < 0.05). FTIR analysis of saliva showed the presence of inorganic phosphates, proteins, lipids, and hormone in the samples tested. Visible difference between FTIR spectra of cleft and non-cleft individuals, specifically in bands of inorganic phosphates, amide I, and amide II were observed. SEM results revealed interconnected filamentous network in the saliva of normal individuals whereas this filamentous network was not present in patients with CLP. In addition to variation in tooth sizes and decreased enamel density, abnormal biochemical composition as well as surface morphology of saliva may contribute to increase caries susceptibility in patients with CLP. Implementation of early oral health care prevention strategy to improve oral health status are essential in patients with CLP.
Modeling k-factors analysis in design of experiment (DOE) towards regression approach using multilayer feed-forward neural network (MLFF): its’ application in biostatistics
(2022-11)
Qadir, Soban
Design of Experiments (DOE) is one of the well-known and widely used statistical methodologies. The results of this DOE provide a very valuable result especially when a researcher studying the relationship between variables. A large number of studies that have been carried out today are hoping for a more accurate result. Indeed, the number of studies involving the development of scientific research methodology is increasing over time. This study aims to develop the best method for data analysis, especially involving a combination of DOE, bootstrap, and linear regression as well as a multi-layer feed-forward neural network (MLFF) through the R programming language. The thesis emphasizes the development of an accurate and valid regression model that involves several combinations of key methods. Based on the results obtained, it can be concluded that this developed methodology shows results encouraging for modeling techniques. In conclusion, this method can be used effectively, especially when performing regression modeling on experimental design.
Physical and mechanical characteristics evaluation of weakened endodontically treated teeth restored with fiber-reinforced composite: open apex and flared root canals
(2023-06)
Alshetiwi, Dawood Salman Dawood
Endodontically treated teeth (ETT) with compromised root canals due to pervasive damage induced by root canal over-instrumentation and incomplete physiological root formation are at high risk of fracture. The use of intra-radicular posts in these teeth is accompanied by a large resin cement layer due to the discrepency in the size and shape between the post and root canal. This study was conducted to assess the combination of different forms of Fiber-reinforced composites (FRC) used to enhance mechanical behavior of compromised ETT. Eighty extracted human premolar teeth were used in this study. Teeth were randomly allocated to five experimental groups with sixteen teeth per group (n = 16). Eight teeth from each group (n = 8) were submitted for objectives 1-3. The remaining eight teeth (n = 8) were prepared for objective 4. Groups were divided according to canal preparation methods and intra-radicular restoration with either a standard prefabricated fiber post or anatomically customized relined fiber post. Samples were then submitted for evaluation of intracanal adaptation using polyvinyl siloxane (PVS) light body impression material and artificial aging using computer-controlled chewing simulator. Fracture resistance and push-out bond strength tests were then carried out through a universal testing machine followed by mode of failure analysis via a stereomicrosope and scanning electron microscope. Assessment of intra-canal adaptation showed a statistically significant difference (p<0.05) in PVS material weight between the groups. Group 1 (control) had the lightest weight of PVS material, followed by groups restored with customized fiber posts (Group 4 and Group 5) and groups restored with standard fiber posts (Group 2 and Group 3). Artificial aging test results through Pairwise Log-Rank comparisons revealed that there was no statistically significant difference between Group 1 (control group), Group 5 and Group 4 (p>0.05). Group 2 and Group 3 showed a statistically significant lower survival rate compared to all other groups. Results of fracture resistance test showed the highest fracture resistance (1796 N) in Group 5, and it was significantly higher compared to other groups (p<0.05), while Group 2 showed the lowest mean fracture resistance (758 N) and was significantly lower compared to the other groups. In relation to push-out bond strength test, Group 5 and Group 4 demonstrated a significantly higher bond strength at all root thirds (p<0.05) than Group 3, Group 2, and Group 1. The most frequently observed failure occurred between the resin cement and radicular dentin for all the groups. In conclusion, the use of short fiber-reinforced composite (SFRC) to reline the prefabricated FRC post has been proven to improve intracanal adaptation and result in higher survival rate, superior fracture resistance with favorable failure patterns and increased push-out bond strength values compared to standard prefabricated FRC posts.
Radiographic analyses of skeletal and dental parameters for age estimation in Malaysian population
(2024-04)
Sigali, Waleed Mohammed Petro
To formulate a new prediction model for the age estimation range between 17-30 years old for both genders in the Malaysian population using oral parameters (root pulp visibility, periodontal ligament visibility, mental foramen and mandibular canal location) and stages of ossification of the medial clavicular epiphyseal cartilage. The study was a cross-sectional comparative study among the Malaysian population attending the clinic in the hospital set up at the Universiti Kebangsaan Malaysia and Universiti Sains Malaysia. Root pulp and periodontal ligament visibility showed a significant mean difference of age, mainly for stage 0 in the ethnic groups involved in the study between males and females. Measurements between right and left mental foramina and mental foramen to the inferior border of the mandible found a significant difference in mean between the ethnic groups after being adjusted for age and sex. There was also a significant difference in mean when measuring the distance from the midline to the right mental foramen between males and females after being adjusted for age and ethnic groups. Measurements from the right and left mandibular canal to the inferior border of the mandible found that there was a significant difference of mean between the ethnic groups after adjusted for age and sex, p-value < 0.001. The age prediction model using a combination of mandible variables, pulp, periodontal ligament visibility, mental foramen, and mandibular canal location showed R2 = 0.561. Hence, the model is considered to have a medium fit. Chest radiograph samples (390) showed a significant mean age difference between males and females, p-value = 0.017, using an independent t-test. Furthermore, there was a significant mean age difference between the ethnic groups, p-value < 0.001, by using a one-way ANOVA test. As for the age prediction model using right medial clavicle union, the ANOVA showed R2 = 0.767. This indicates that the final model explains 76.7% of the total variance in age. Hence, the model is considered to have an excellent fit. Using multi-factorial radiological methods showed good results while consuming less time and effort. Digital chest radiographs were a useful tool for predicting age.
Study of mild-moderate traumatic brain injury using tract-based spatial statistics (TBSS) and its relationship with cognitive function
(2023-09)
Abdullah, Aimi Nadhiah
Traumatic brain injury (TBI) is known to lead to cognitive function impairment. The degree of impairment, however, varies depending on the severity and time post-TBI. Diffuse axonal damage has been discovered as the underlying pathology even in mild TBI. Thus, this study aims to determine the state of white matter putative connectivity in patients with mild-moderate TBI in the subacute phase, or within 10 weeks of injury, and its correlation to cognitive scores. A case-control prospective study was conducted involving 11 male patients with mild-moderate TBI and an age-matched control group of 11 adult male volunteers. Diffusion MRI scanning and cognitive testing were performed within 10 weeks of injury. The difference in fractional anisotropy (FA) values between TBI patients and control group was studied using tract-based spatial statistics (TBSS). Then, the FA values that were significantly different between patients and controls were correlated with neuropsychological tests in the TBI group. When comparing patients to the control group, several clusters with peak voxels of substantial FA reductions (p < 0.05) in the white matter skeleton were seen. These clusters were later treated as region of interest and were found in the superior fronto-occipital fasciculus, superior longitudinal fasciculus, uncinate fasciculus, and cingulum. White matter fibres in the region of the genu of the corpus callosum, anterior corona radiata, superior corona radiata, anterior thalamic radiation, and a portion of the inferior frontal gyrus also contained these clusters. Region of interest analysis revealed FA values significantly correlated with Malay version of Auditory Verbal Learning Test (MAVLT) immediate recall scores in the region of genu of corpus callosum (r = 0.62, p = 0.004) and right superior fronto-occipital fasciculus (r = 0.50, p = 0.026). Matrix-reasoning scores positively correlated with FA values in the region of right superior fronto-occipital fasciculus (r = 0.45, p = 0.045) and left anterior corona radiate (r = 0.47, p = 0.036), while having negative correlation in the region of right superior fronto-occipital fasciculus (r = -0.49, p = 0.030). Mean diffusivity (MD) values significantly have positive correlation with both Rey Complex Figure Tests (RCFT) immediate (r = 0.593, p = 0.015) and delayed (r = 0.640, p = 0.002) scores in the right superior longitudinal fasciculus. During the sub-acute phase of TBI, the mild-moderate TBI patients showed unusually decreased FA values and increase MD values compared to controls, which suggested disruption of white matter tracts. The correlation between FA values with neuropsychological scores further provide evidence of cognitive impairment probably responsible by the structural disruption.
The cytotoxicity and antimicrobial activity of andrographis paniculata herbal mouthwash formulation
(2023-02)
Alojid, Anis Amiera Muhamad
Oral disease is a global health problem caused by oral pathogens. To prevent the oral disease, mouthwash is commonly used. However, commercial mouthwash contained alcohol and other chemicals found to be toxic with unfavourable side effects. Besides, existence drugs seemed to be ineffective due to excessive use and multidrug resistance against the oral pathogens. Thus, there is a demand for a safer and effective alternative treatment in dental product. As the studies on cytotoxicity and antimicrobial activities of medicinal herb, Andrographis paniculata (AP) against oral pathogens are limited, this study proposed AP aqueous extract as herbal mouthwash to determine its effectiveness against selected oral pathogens; Porphyromonas gingivalis, Streptococcus mutans, S. sobrinus, Staphylococcus aureus, and Actinomyces viscosus. In this study, antibacterial effect of AP aqueous extract against the tested oral pathogens was determined by disc diffusion and well diffusion assays, followed by antibacterial effect of five concentrations of AP herbal mouthwash at 1000, 500, 250, 125 and 62.5 mg/mL using well diffusion and broth microdilution method. Assessment of toxicity was determined by brine shrimp lethality bioassay and 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay onto L929 fibroblast cells while the analysis of heavy metal was analysed using atomic absorption spectrometry (AAS). Stability study was carried out on the final product of AP herbal mouthwash. Results revealed that AP aqueous extract significantly inhibited the growth of all oral pathogens (p<0.05) except for S. aureus with inhibition zones ranging from 2.83 ± 0.83 mm to 14.37 ± 0.83.mm. Similar to AP aqueous extract, AP herbal mouthwash exhibited significant antibacterial activities onto all tested pathogens except for S. aureus (p<0.05) with inhibition ranging from median (IQR) of 9.50 (3.80) to median (IQR) of 15.00 (3.40). All mouthwash concentrations caused bacteria inhibition from 10.56% to 261.09% with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) at 3.90 mg/mL to 7.81 mg/mL and 7.81 mg/mL to 62.50 mg/mL respectively. However, there was no MBC detected for S. aureus at these concentrations. Formulation of mouthwash was non-toxic to brine shrimp and L929 fibroblast cell line with LC50 value 3255.06 μg/mL and IC50 value 43.55 mg/mL respectively. AP herbal mouthwash was free from heavy metal contamination and maintained its characteristics and sterility for 12 months storage. In conclusion, AP herbal mouthwash at 7.81 mg/mL was found to be the best mouthwash formulation. However, more research works need to be carried out for its clinical use for further product commercialization.

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