Pusat Pengajian Sains Pergigian - Tesis
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- PublicationModeling 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, SobanDesign 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.
- PublicationBacterial leakage and marginal adaptation of three bioceramics pulp dressing material(2023-04)Siddiqua, Snigdha Niher TabassumThis 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.
- PublicationThree-dimensional morphometric analysis of mandibular foramina: a cone beam computed tomography study comparing Mahajir and Pukhtoon ethnics in Pakistan.(2024-08)Alam, Beenish FatimaA thorough understanding of the anthropometric landmarks on the mandible and their clinical application is necessary, before performing any surgical procedure to reduce the risk of inferior alveolar nerve injury. Cone bean computed tomography (CBCT) is a widely recognised diagnostic tool that generates high-quality, accurate images and assists in identifying the precise location of anatomical components. It has been utilised as instruments for facilitating preoperative planning of surgical procedures. This study aimed to identify the foramen located on the surface of mandible, and to determine their number, shape, classification, dimensions, position, and their distance to various anatomical landmarks. Another objective is to determine the association of mandibular foramen location with mandibular body and ramus height and length between sexes, between right and left sides, and between Mahajir and Pukhtoon ethnic groups of Pakistan. Four hundred CBCT from Mahajir and Pukhtoon Pakistani populations were collected from Khans Dental Institute, Karachi from 2016 to 2021. CBCT imaging was carried out using the New Tom VGi machine (NewTom Co., Ltd., Shawnee, Italy). Image processing and morphometric analysis of the mandibular foramina was conducted using MIMICS software (Materialise, Belgium). Statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS), version 28.0 (IBM SPSS Statistics, Armonk, NY, USA). The results of this investigation showed that midline lingual foramen was the most common form. Pukhtoon ethnicity had larger lingual foramen dimensions overall, while males exhibited larger measurements in terms of size. The Pukhtoon ethnic group exhibited a greater distance from landmarks to lingual foramen. The most prevalent shape of mental foramen was round. In terms of size and distance to landmarks, Pukhtoon showed longer measurements from mental foramen. The most typical horizontal location was next to the second premolar, and the most frequently observed vertical position was apical to the tooth's root apex. The round shape was the common for accessory mental foramen while irregular and oval shapes were more prevalent on both sides of accessory mandibular foramen. Additionally, oval shapes were observed to be more prevalent on the right and left side of mandibular foramen. Similarly, the mandibular foramen and accessory mandibular foramen dimensions and distance to landmarks were observed to be greater in Pukhtoon ethnicity. A weak but positive correlation was detected between mandibular foramen with ramus width, height, and length of the mandibular body. This study provided valuable insight and clinical reference values regarding dimensions and distances to anatomical landmarks of all foramina of the mandible for the Mahajir and Pukhtoon ethnicity in Pakistan as well as according to different sexes and sides, which potentially be useful during pre-surgical evaluation of the mandible.
- PublicationA new regression modelling approach and its application in biostatistics(2024-07)Eusufzai, Sumaiya ZabinThis 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.
- PublicationProteomics approaches in identification of key signalling pathways associated with collagen type 1-induced osteogenic differentiation of dental stem cells(2024-07)Nasir, Nur Julia NabilaCollagen type 1 (Col-1) is a promising scaffolding material in bone regeneration approach. However, the predominant signalling pathway involved when dental pulp stem cells (DPSC) cultured on the scaffold are still poorly understood. This study analysed the stemness of the DPSC prior to the studies of relevant signalling pathways involved and the proteomic profiles to determine the mechanism underlying the Col-1 induced osteogenesis. Characterisation of DPSC were analysed via its morphology, MSC surface markers, population doubling level as well as differentiation capacity. For the signalling pathways analysis, cells were grouped into complete culture medium (CCM; negative control), osteogenic induction medium (OIM; positive control) and Col-1 without and with three different pathway inhibitors: LY294002 (PI3K/AKT inhibitor), LY23200882 (TGF-β/Smad inhibitor) and PD98059 (MAPK/ERK inhibitor). Western blot analysis over 7, 14, and 21 days and LC-MS/MS proteomic profiling on day 21 revealed that the PI3K/AKT signalling pathway is crucial for the osteogenic differentiation of DPSC on both OIM and Col-1 group. PI3K/AKT pathway was predominant throughout the 21 days of Col-1 induced osteogenesis, while MAPK/ERK and TGF-β/Smad was more relevant at earlier and later stage, respectively. Crosstalk between signalling molecules showed bidirectional or unidirectional dependent to each other, where AKT activation can be influenced by Smad, but not vice versa. Likewise, Smad activation can be influenced by ERK1/2, but not the other way around. Proteomic profiling of Col-1 induced osteogenesis showed majority of the proteins were associated with glycolysis, carbon metabolism, biosynthesis of amino acid and focal adhesion.