Pusat Pengajian Sains Pergigian - Tesis

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The synthesis and characterization of hydroxylapatite microtubules/polylactic acid GTR membranes and its effect on periodontal bone regeneration
(2024-11)
Junyan, Wang
The general objective of the study is to develop novel hydroxylapatite microtubules/PLA GTR membranes and evaluate them for mechanical and biological properties. HAp microtubules were prepared through hydrothermal synthesis. The composition and morphology of the synthesized materials were examined by a scanning electron microscope (SEM), transmission electron microscopy (TEM), Xray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Then the novel hydroxylapatite microtubules/PLA GTR membranes were fabricated. The membranes were verified whether they met the clinical mechanical requirements in degradation and stretching properties. In addition, we examined its interaction with human periodontal ligament stem cells (hPDLSCs), harvested from healthy teeth. The osteogenic effect of the membrane on hPDLSCs was examined by evaluating the gene and protein expressions of the RUNX2, OPN, and OCN using Quantitative PCR (qPCR) and Western blotting analysis, respectively. In this study, all data for the mechanical property tests, which include water contact angle tests, tensile tests, swelling analysis and biodegradation analysis were expressed as mean and standard deviation. For cell proliferation and osteogenic differentiation experiments, the data were numerical. The normality of distribution was assessed using Q-Q plot analysis. In some cases, natural log transformation was employed to aid in representing data that exhibited normal distribution. The significance level was set at p = 0.05. The HAp microtubules/PLA membrane had better tensile and breaking strengths and lower fracture productivity than the PLA membrane. The expansion rate reached 34% after 2 h, and the degradation rate exceeded 25% after 40 days. Water contact angle measurement results showed that the bilayer membrane was hydrophilic on one side and hydrophobic on the other side. The results of the cell experiments also showed that the membrane had no cytotoxicity. The number of cells in the HAp microtubule/PLA membrane group was found to be significantly higher than that observed in the group with a PLA membrane (p<0.05). Furthermore, the expression of genes and proteins associated with bone composition was significantly elevated in the HAp microtubule/PLA membrane group compared to the HAp powder/PLA membrane and hPDLSCs group (p<0.05). The HAp microtubule side can promote the expression of genes and proteins related to osteogenesis, while the PLA side can inhibit cell adhesion. The HAp microtubules/PLA membrane has stability and good mechanical properties. The double-layer structure has the function of a biological barrier and promotes bone formation.
A novel classification for coronal remaining dentine thickness in carious teeth
(2025-01)
Maqbool, Manahil
Dental caries is a prevalent issue impacting a significant portion of the population. The part of coronal dentine that remains following a carious attack is referred to as the remaining dentine thickness (RDT). The amount of RDT left after caries significantly influences diagnosis and treatment planning. This study aimed to introduce a novel classification that categorises coronal RDT based on its decreasing thickness and information on its related factors. A comprehensive study design incorporating a systematic review (SR), an in vitro experiment, and a modified Delphi technique was employed. Articles measuring coronal RDT were screened for the SR. For the in vitro experiment, human extracted carious molars and premolars were used, in which the RDT was measured utilising digital periapical radiographs, cone-beam computed tomographic (CBCT) scanning, and Hirox stereomicroscopy (histological sections). The classification framework was constructed using the identified factors, and validated using the modified Delphi technique with the help of international experts in the field of caries management. A content analysis was conducted on the articles included for the SR, one-way ANOVA was applied to compare the RDT measurements obtained during the in vitro experiment, and a content validity index (CVI) was utilised to assess the consensus agreement among international experts participating in the modified Delphi process. A total of 17 articles were included in the SR after the full-text screening, upon which the content analysis was performed. Only 63 teeth were used in the in vitro experiment, that met the inclusion and exclusion criteria. No significant difference was observed in RDT values acquired using CBCT and Hirox. Nonetheless, a significant difference (p<0.05) was observed between digital radiographs and CBCT, as well as between digital radiographs and Hirox. A total of 10 components were identified from the SR/content analysis and in vitro experiment, that helped in constructing the Dentinal Triage framework. Next, this framework underwent validation utilising three rounds of modified Delphi with 22 international experts, yielding item-CVI scores of 0.89 (89%), 0.97 (97%), and 0.98 (98%), respectively; indicating a strong consensus agreement among the international expert panel in regards to the entire Dentinal Triage by the end of round three. In conclusion, it was observed that digital radiography overestimated RDT relative to CBCT and Hirox microscopy. Nevertheless, it still served as the most practical chairside tool for assessing coronal RDT. The novel coronal RDT classification, the Dentinal Triage, was developed and successfully validated with a 98% consensus agreement amongst the international dental experts in caries management.
Prevalance of sleep-disorded breathing and efficacy of twin block appliance treatment in saudi children with class ii malocclusion and obstructive sleep apnoea
(2024-12)
Zreaqat, Ma’en Hussni Rashid
Obstructive sleep apnoea (OSA) is a disorder of breathing during sleep characterized by prolonged partial upper airway obstruction and/or intermittent complete obstruction that disrupts normal ventilation during sleep and normal sleep patterns. It is an increasing major public health concern worldwide, partly resulting from the obesity epidemic which has encroached into the pediatric population. Individuals with a Class II skeletal malocclusion may suffer from snoring due to a retrognathic position of the mandible resulting in a retro-glossal tongue position which restricts posterior pharyngeal airway space which may result in obstructive sleep apnoea. This sleep pathology carries devastating health consequences resulting in hypertension, ischemic heart disease and stroke and associated with insulin resistance. Children who are sleep deprived often demonstrate nocturnal enuresis, daytime fatigue, hyperactivity and poor performance at school. Early recognition of this condition through routine dental clinical examination, standard screening questionnaires, and further craniofacial cephalometric analysis may help in early diagnosis and treatment. There is a growing body of evidence that shows the effective role of myofunctional appliances in the management of obstructive sleep apnoea associated with Class II skeletal malocclusion. The anterior displacement of the mandible guided by this device is able to widen the posterior pharyngeal airway space, reducing the upper airway resistance and improves airflow while breathing throughout the night. The aims of this study were first: To determine the prevalence of sleep disordered breathing among Saudi school children as a population-based study using the Pediatric Sleep Questionnaire (PSQ), and second: To evaluate the impact of twin block management on upper airway CBCT dimensions, oropharynx parameters, biochemical levels, and quality of life in OSA children with Class II skeletal malocclusion. This prospective cohort study comprised polysomnography-proven OSA growing children with class II skeletal malocclusion and mandibular retrognathia in the age range of 8 to 12 years who have completed twin block treatment and matched corresponding controls. Results showed that twenty three percent of Saudi school children were at high risk of developing SDB with male predilection as a risk factor. Snoring, sleep apnoea, and mouth breathing were prevalent in high-risk SDB children. There is a strong association between increased body mass index (BMI) and SDB. The epidemic spread of obesity among Saudi school children and its negative impacts merit serious discussion in future health strategies. Male gender, increased BMI, high tonsil and Mallampati scores were clinical indicators of the presence of OSA. However, only Mallampati scale was associated with severity of OSA. Due to the financial burden for of polysomnography (PSG), clinical diagnostic indicators should be established and encouraged especially in community based studies. The results of CBCT scans analysis showed that children with OSA have a smaller oropharynx volume, minimum cross-sectional area (CSAmin), anterio-posterior and lateral dimensions of CSAmin, hypopharynx CSAmin, and increased upper airway length compared to corresponding controls. A small CSAmin seems to be the most relevant anatomical variable in the pathogenesis of OSA. The current study shows that correction of class II skeletal malocclusion and mandibular retrognathia with twin-block appliance resulted in significant increase of upper air way parameters.
Mobile application gigiku sihat to improve dietary habit and oral hygiene among children aged 4 to 6 years and dietary and oral health knowledge, attitude and practice among parents: a community intervention study in Kelantan
(2025-04)
Zulkefle, Rumaisa’
Maintaining good oral health in children involves a combination level of parental knowledge, attitude, and persistent behavioral routines towards children’s nutrient and oral health. The ability of smartphone to overcome barriers in conventional education method is needed since more parents depend on it nowadays. In order to improve dietary habits and oral health, app of Gigiku Sihat (GS) was developed targeted to parents of preschool children. Aim of this study was to evaluate the effectiveness of mHealth apps Gigiku Sihat for improving dietary habits and oral health among 4- to 6-year-olds children at KEMAS preschool in Tumpat and Pasir Mas, Kelantan and their parents’ nutrition and oral health knowledge, attitude, and practice (KAP). A cluster randomized trial was done. During the study period, participants in the intervention group (IG) used GS installed in their mobile device, while the control group (CG) received TIP TOP which was delivered once during the first visit. The sample size was 60 for each IG and CG. Primary outcome measures including parental nutrition and oral health KAP and children’s cariogenic food frequency (CFF) were evaluated through validated self-administered questionnaires, and OH status was determined through clinical examination using Simplified Oral Hygiene Index (OHI-S). Measurement of variables were done at baseline, 4- (Evaluation 1) and 8-weeks (Evaluation 2) post-intervention. Descriptive analysis, independent t-test, and repeated measures ANOVA were performed with significance level set at p<0.05. A total of 116 parent-child pairs (IG:56, CG:60) completed the study. Both groups have more girls compared to boys. Majority of parents in both groups aged 30-39 years old (IG:73.2%, CG:53.3%); had finished secondary school as their highest education level (IG:48.2%, CG:66.7%); were housewife or not working (IG:41.1%, CG:68.3%); had less than 6 family members (IG:62.5%, CG:55%) and had monthly household income of RM1,000 - RM1,999 (IG: 32.1%, CG:45.0%). Most of parents in IG (35.7%) had spent RM500-RM599 monthly for food, while most of parents in CG (31.7%) had monthly expenditure of RM700-RM799. The main water supply for both groups was from AKSB (pipe water) (IG:69.6%, CG:73.3%). At Evaluation 1, IG showed significantly lower mean CFF score in the categories of biscuits (p=0.017), crisps (p=0.024, 0.003), soya bean-based milk (p=0.007) and sugared drinks /condensed milk (p=0.042). At Evaluation 2, significantly lower mean CFF scores was also observed in IG for traditional kuih (p=0.006), chocolate (p<0.001), crisps (p=0.003), sweets (p=0.047), processed fruits (p=0.002), soya bean-based milk (p<0.001) and sugared drinks /condensed milk (p=0.004). There was a significantly lower OHI-S score (p=0.023) and higher attitude score (p=0.041) at Evaluation 2 in IG as compared to CG. There was no significant difference in parental knowledge and practice scores between the IG and CG. GS was effective in improving parental attitude score, children’s oral health, as well as some categories of CFF of the preschool children. Mobile application, dietary habits, oral hygiene, KAP, preschool and parents.
Antimicrobial enhancement of denture base resin using microcapsule drug delivery technology: a characterization study
(2025-05)
Mahadi, Nik Nur Syahidatul Jannah
Denture stomatitis (DS) presents as a common inflammatory reaction in denture wearing patients. It is highlighted that the rising demand for dentures, particularly among the elderly, due to factors such as aging populations and associated health issues affecting oral hygiene. Alternatively, new development of antimicrobial elimination that could effectively inhibit the growth of oral bacteria could be an active area of research. The aim of this study is to investigate the antimicrobial interaction of PLA/TTO microcapsules in polymerized PMMA denture base resin against Staphylococcus aureus, Streptococcus mutans and Candida albicans. A new drug delivery methodology employed via emulsion and solvent evaporation (ESE) techniques was performed to synthesize polylactic acid (PLA) microcapsules containing antimicrobial agents; tea tree oil (TTO). The characterization of TTO/PLA microcapsules were characterized using Ultraviolet-visible (UV-Vis), Fourier-transform Infrared (FTIR), Gas chromatography-mass spectrometry (GCMS) and field emission scanning electron microscope (FESEM). The modified PMMA denture base was prepared in three different concentrations of prepared microcapsules (TTO: PLA (% w/w)), 10%, 50% and 100%. For antimicrobial activity, the modified PMMA was evaluated for antimicrobial activity through leaching solution at the intervals of 7th, 14th and 30th days using the well diffusion test and time-killed assay. Then, FESEM images was performed to assess the attachment of microorganism on the surface of modified denture base. The results obtained from characterization analysis showed the microcapsules were successfully synthesized using emulsion and solvent evaporation method where the drug release study and the average particle size formed is homogenously distributed for controlled drug release. The antimicrobial activity of modified PMMA base resin incorporated with PLA/TTO microcapsules showed a good antimicrobial effect (Table 4.2/4.3/4.4/4.5) and statistically revealed a significant effect (p<0.05) against S. aureus and C. albicans where the inhibition area increased as the concentration increased except for S. mutans. The time killed assay was used to study the antimicrobial agent over the time, it showed that the antimicrobial activity of modified denture base exhibited a good antimicrobial effect against all microorganism tested. In morphological test using FESEM, the attachment of fungal and bacteria cell tested is lesser as the concentration increased within 24 hours studied. The study revealed incorporation of PLA/TTO microcapsules in denture base, has significant impacted on enhanced antimicrobial activity, offering potential usefulness for denture users in the future. However, further studies including physical properties and cytotoxicity are needed to be investigated before the clinical trials.

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