An assessment of the pH changes and metal ions released into artificial saliva by fake orthodontic braces.

BACKGROUND: This present study assesses changes in the pH as well as the metal ions that fake braces release into artificial saliva (AS) using a pH meter and inductively coupled plasma atomic emission spectroscopy (ICP-AES), respectively. METHODS: Three sets of fake archwires (AWs) and brackets (Bs) as well as a set of controls were immersed in AS and placed in an incubator shaker at 50 rpm and 37°C. At Days 0, 1, 7, 14, 21, and 28, the pH of the AS medium was measured and 3.0 ml of AS was collected and stored at -20°C for elemental analysis. RESULTS: Significant changes in pH were observed on Days 0, 1, 7, 14, 21, and 28 in the AS of the AW group. However, these changes were only observed in the B group on Days 0 and 7. The fake samples released a large quantity of sodium (Na), potassium (K), and calcium (Ca) ions, at concentrations exceeding 100 mg/L, post-28 days of immersion. The control and fake braces samples released other ions; such as lithium (Li), magnesium (Mg), barium (Ba), chromium (Cr), copper (Cu), lead (Pb), and aluminium (Al); at concentrations that did not exceed 10 mg/L. CONCLUSIONS: The pH of the AS of all the samples increased post-incubation. Only 10 ions; namely, Na, Li, K, Mg, Ca, Ba, Cr, Cu, Pb, and Al; were detected in the AS.

Combination of Goniothalamin and Sol-Gel-Derived Bioactive Glass 45S5 Enhances Growth Inhibitory Activity via Apoptosis Induction and Cell Cycle Arrest in Breast Cancer Cells MCF-7.

Background: Combination of natural products with chemically synthesised biomaterials as cancer therapy has attracted great interest lately. Hence, this study is aimed at investigating the combined effects of goniothalamin and bioactive glass 45S5 (GTN-BG) and evaluating their anticancer properties on human breast cancer cells MCF-7. Methods: The BG 45S5 was prepared using the sol-gel process followed by characterisation using PSA, BET, SEM/EDS, XRD, and FTIR. The effects of GTN-BG on the proliferation of MCF-7 were assessed by MTT, PrestoBlue, and scratch wound assays. The cell cycle analysis, Annexin-FITC assay, and activation of caspase-3/7, caspase-8, and caspase-9 assays were determined to further explore its mechanism of action. Results: The synthesised BG 45S5 was classified as a fine powder, having a rough surface, and contains mesopores of 12.6 nm. EDS analysis revealed that silica and calcium elements are the primary components of BG powders. Both crystalline and amorphous structures were detected with 73% and 27% similarity to Na2Ca2(Si2O7) and hydroxyapatite, respectively. The combination of GTN-BG was more potent than GTN in inhibiting the proliferation of MCF-7 cells. G0/G1 and G2/M phases of the cell cycle were arrested by GTN and GTN-BG. The percentage of viable cells in GTN-BG treatment was significantly lower than that in GTN. In terms of activation of initiator caspases for both extrinsic and intrinsic apoptosis pathways, caspase-8 and caspase-9 were found more effective in response to GTN-BG than GTN. Conclusion: The anticancer effect of GTN in MCF-7 cells was improved when combined with BG. The findings provide significant insight into the mechanism of GTN-BG against MCF-7 cells, which can potentially be used as a novel anticancer therapeutic approach.

Assessment of stress shielding around a dental implant for variation of implant stiffness and parafunctional loading using finite element analysis.

PURPOSE: The aim of this study was to evaluate the mechanical stimuli transfer at the bone-implant interface via stress and strain energy density transfer parameters. This study also aimed to investigate the effect of different implant stiffness and parafunctional loading values on the defined mechanical stimuli transfer from the implant to the surrounding bone. METHODS: A three-dimensional finite element model of two-piece threaded dental implant with internal hexagonal connection and mandibular bone block was constructed. Response surface method through face-centred central composite design was applied to examine the influence of two independent factors variables using three levels. The analysis model was fitted to a second-order polynomial equation to determine the response values. RESULTS: The results showed that the implant stiffness was more effective than the horizontal load value in increasing the stress and strain energy density transfers. The interaction between both factors was significant in decreasing the likelihood of bone resorption. Decreasing the implant stiffness and horizontal load value led to the increased stress transfer and unexpected decrease in the strain energy density, except at the minimum level of the horizontal load. The increase in the implant stiffness and horizontal load value (up to medium level) have increased the strain energy transfer to the bone. CONCLUSIONS: The stress and strain energy density were transferred distinctively at the bone-implant interface. The role of both implant stiffness and parafunctional loading is important and should be highlighted in the preoperative treatment planning and design of dental implant.

Metal ions leachables from fake orthodontic braces incubated in simulated body fluid.

BACKGROUND: The demand for fake braces usage in Southeast Asia are increasing but lack of certification and information on fake braces as medical devices from regulated bodies raised a concern towards its safety. The aim of this study was to determine the types of metal ion leachable from removable fake braces based on heavy metal ions present in metallic materials, immersed in simulated body fluid (SBF) and analysed using inductively coupled plasma atomic emission spectroscopy. METHODS: Three sets of fake braces and one control were dissembled to only their brackets and archwires and immersed separately in SBF. They were placed in an incubator shaker at a temperature of 37 °C at 50 rpm. A 3.0 ml measurement of SBF was taken out from the sample containers at days 7, 14 and 28 and kept at - 20 °C for further analysis. Data were analysed using SPSS version 26.0 (IBM, Armonk, USA) (P < 0.05). Descriptive and one-way ANOVA analyses with Bonferroni post hoc tests were used to assess the significant differences between the metal ions released in SBF from the control samples and fake braces. RESULTS: All 23 elements under investigation except Si ions were detected from the control samples and fake braces. There were significant increased K ions and reduced levels of Mg ions from the fake archwires and brackets. Most ions released were less than 10 mg/L (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, Pb, Al) or 1 mg/L (Li, Ba) into the SBF medium. CONCLUSION: There were significant release of Ca and K ions from the fake samples. Elements such as Li, Ba, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd and Sb had increased in concentration at day 7 and the concentration plateaued until day 28.

The accuracy of demirjian method in dental age estimation of malay children.

This study is aimed to evaluate the accuracy of Demirjian method in estimating the chronological age of male and female Kelantanese Malay children between 6 and 16 years of age and to establish a new dental age (DA) curve if the Demirjian method was not found to be accurate. About 905 panoramic radiographs of healthy Malay children between 6 and 16 years of age were collected from the radiographic unit in the Hospital Universiti Sains Malaysia (HUSM) and the orthodontic clinic in Hospital Kota Bharu (HKB). Children who had any disease affecting the dental development, or have agenesis in the lower arch and poor quality radiographic images were excluded. The results showed that Demirjian method overestimated the chronological age (CA) by 1.23 years for boys and 1.20 years for girls and it was less accurate for the Kelantanese Malay children. Thus new standard curve were produced and tested on external samples. Results showed that the mean difference between the chronological age and DA is about 0.17 years for boys and 0.11 years for girls. DA was more advanced in the Kelantanese Malay boys and girls as compared to French-Canadian children in all age groups. It is concluded that the Demirjian method tends to be less accurate in estimating the chronological age in Malay children. The new curve that was produced is more applicable to the Kelantanese Malay children.

Microleakage assessment of a repaired, nano-filled, resin-based fissure sealant.

PURPOSE: The purpose of this study was to evaluate the effects of different repairing techniques of a fractured sealant on microleakage in vitro. METHODS: A nono-filled flowable composite (Filtek Z350) was placed on the occlusal surfaces of 112 intact extracted molars following cleoning by prophylaxis and acid etching. Sealant failure was produced on the entire sample. The teeth were then randomly allocated into 4 groups, each representing a different method of repair: group 1 (control)-prophylaxis brush followed by acid etching and 10 seconds of curing time; group 2-prophylaxis brush, acid etching, application of bonding agent, and 10 seconds of curing time; group 3-prophylaxis brush, acid etching, and 5 seconds of curing time; and group 4-prophylaxis brush, acid etching, and 20 seconds of curing time. Then, they were pointed with varnish and immersed in 1% methylene blue. The teeth were then sectioned, and a total of 648 surfaces were scored for microleakage. RESULTS: Statistical analysis did not demonstrate any one method of repair to be superior to the control method. There were no significant differences in microleakage between 10 and 20 seconds of curing time. CONCLUSION: Prophylaxis brush, acid etching, and light-emitting diode light curing for 10 seconds seems to be the simplest and the most appropriate method of repair and is, therefore, recommended.

Variations in tooth size and arch dimensions in Malay schoolchildren.

AIMS: To compare the mesio-distal tooth sizes and dental arch dimensions in Malay boys and girls with Class I, Class II and Class III malocclusions. METHODS: The dental casts of 150 subjects (78 boys, 72 girls), between 12 and 16 years of age, with Class I, Class II and Class III malocclusions were used. Each group consisted of 50 subjects. An electronic digital caliper was used to measure the mesio-distal tooth sizes of the upper and lower permanent teeth (first molar to first molar), the intercanine and intermolar widths. The arch lengths and arch perimeters were measured with AutoCAD software (Autodesk Inc., San Rafael, CA, U.S.A.). RESULTS: The mesio-distal dimensions of the upper lateral incisors and canines in the Class I malocclusion group were significantly smaller than the corresponding teeth in the Class III and Class II groups, respectively. The lower canines and first molars were significantly smaller in the Class I group than the corresponding teeth in the Class II group. The lower intercanine width was significantly smaller in the Class II group as compared with the Class I group, and the upper intermolar width was significantly larger in Class III group as compared with the Class II group. There were no significant differences in the arch perimeters or arch lengths. The boys had significantly wider teeth than the girls, except for the left lower second premolar. The boys also had larger upper and lower intermolar widths and lower intercanine width than the girls. CONCLUSION: Small, but statistically significant, differences in tooth sizes are not necessarily accompanied by significant arch width, arch length or arch perimeter differences. Generally, boys have wider teeth, larger lower intercanine width and upper and lower intermolar widths than girls.

Utilization of dental general anaesthesia for children.

Dental treatment under general anaesthesia may be needed for some children and adolescents due to medical or behaviour problem. The objective of the study is to identify the type of treatment that has been carried out under GA in Hospital Universiti Sains Malaysia (HUSM). A retrospective record review study from hospital records of dental patients (under 18 years old) receiving dental treatment under GA from 2003 until 2007 were retrieved from the database. Information such as the reason for GA, and the type of treatment provided was recorded in data sheet. The data were analyzed using SPSS 12.0.1 for Windows. It was checked and verified for errors. A total of 349 cases were treated of which 43.6% had medical problems. Patients were mostly diagnosed to have rampant caries (77.1%) and some of them have behavioural problems (34.4%). Treatment pattern in deciduous dentition revealed more extraction (97.8%) as compared to restoration (75.7%) whereas in permanent dentition more restoration was done (24.3%) as compared to extraction (2.2%). Majority of the restorations were done using Glass Ionomer Cements (47.5%). Biopsy (4.3%) contributed mainly to the surgery (24.1%) done during GA. General anesthesia is necessary when dental disease is interfering with health and general well-being of patient and it can facilitated dental treatment allowing dentists to benefit from improved treatment conditions and provide a higher quality of care.

Assessment of patients' level of satisfaction with cleft treatment using the Cleft Evaluation Profile.

OBJECTIVES: Determination of the psychosocial status and assessment of the level of satisfaction in Malaysian cleft palate patients and their parents. DESIGN: Cross-sectional study. PARTICIPANTS AND METHODS: Sixty cleft lip and palate patients (12 to 17 years of age) from Hospital Universiti Sains Malaysia and their parents were selected. The questionnaires used were the Child Interview Schedule, the Parents Interview Schedule, and the Cleft Evaluation Profile (CEP), administered via individual interviews. RESULTS: Patients were teased because of their clefts and felt their self-confidence was affected by the cleft condition. They were frequently teased about cleft-related features such as speech, teeth, and lip appearance. Parents also reported that their children were being teased because of their clefts and that their children's self-confidence was affected by the clefts. Both showed a significant level of satisfaction with the treatment provided by the cleft team. There was no significant difference between the responses of the patients and their parents. The features that were found to be most important for the patients and their parents, in decreasing order of priority, were teeth, nose, lips, and speech. CONCLUSIONS: Cleft lip and/or palate patients were teased because of their clefts, and it affected their self-confidence. The Cleft Evaluation Profile is a reliable and useful tool to assess patients' level of satisfaction with treatment received for cleft lip and/or palate and can identify the types of cleft-related features that are most important for the patients.