Evaluation and response of dental pulp stem cells following pulp capping procedure using calcium hydroxide cement and gic or restorative procedure using gic in primary molars

The biological examination of pulp injury, repair events and the response of dental pulp stem cells to dental restorative materials is of paramount importance for understanding the post operative development and the use of these repair activities to accomplish restorative treatment.The structure of the tooth is almost always exposed to different dental materials and the deciduous teeth are known to be a rich source of stem cells. Therefore, it is important to evaluate the response of dental pulp stem cells to the commonly used dental materials in pediatric dentistry such as Glass Ionomer Cement (GIC) and Calcium hydroxide Ca(OH)2 lining cement. The aims of this study were to confirm the presence of stem cells in deciduous extracted teeth by immunocytochemistry, and evaluate the stem cells proliferative activity and their response by comparing the Tertiary Dentin Thickness (TDT) formation following restorative procedures on the teeth. Healthy pediatric dental patients aged between 9 to 11 years old with caries teeth on primary molars without pulpal exposure who attended the pediatric dental clinic for dental treatment in School of Dental Sciences, Health Campus, Universiti Sains Malaysia, were selected.The teeth were divided into two groups: for Group 1 the teeth were filled with GIC(Fuji IXGP capsule, GC, Japan) alone and in Group 2, the teeth were lined with Ca(OH)2 cement (Dycal ®, Dentsply, Germany) and filled with GIC (Fuji IXGP capsule, GC, Japan).The teeth were reviewed for up to 6 months before being extracted according to the selected criteria and under standardized normal procedures. The presence of stem cells in deciduous teeth was confirmed by immunocytochemistry using surface antigenic markers CD 1 OS and CD 166.Colocimetric proliferation reagent alamarBlue™ was used to evaluate the proliferative activity for Group 1 and Group 2. The dental pulp stem cells response following restorative procedures was evaluated using Haematoxyline and Eosin (H&E) staining for histological section under a microscope using image pro software (Media cypemetics. Inc., USA). Stem cells from human extracted deciduous teeth were found positive for CD 105 and CD 166. The proliferative activity for both Group 1 and Group 2 showed slight difference, but it was not statistically significant.However, the TDT areas in Group 2 were significantly more than Group 1. The pulp of deciduous teeth contains stem cell population and following pulp capping procedure using Ca(OHh cement (Dycal®, Dentsply, Germany) and GIC (Fuji IXGP capsule, GC, Japan), responded well and maintained their proliferative activity. However, these materials create different response of SHLD tertiary dentin appeared to be more under restorations lined with Ca(OHh. Thus Ca(OHh cement has high credibility to be used in deep cavities for pulp protection

Descriptive Results Of Digital Dentisty Readiness Among Dental Practitioners In Malaysia

Technology application in dentistry evolved dramatically allowing easy data management. Dental practice equipped by ICT application enables the improvement in work flow and efficiency due to huge number of software available that serves many non-internet clinical applications as well as administrative application technology

Effect of Vitamin E on Human Periodontal Ligament Fibroblasts

The periodontal ligament fibroblasts plays an essential role in the organization and maintenance of the connective tissue during development and in response to injuries and diseases. They are also responsible of the migration and differentiation of the variety of cells that takes part in the osteogenesis in response to external forces (1, 2). Age related changes include decreased fibroblasts density and cellular activity which slows orthodontic tooth movement due to prolonged response of the connective tissue to external forces which poses a potential risk in orthodontic treatment (3, 4). Vitamin E had been studied worldwide due to its health benefits in the fields of chronic diseases and ageing such as the anti-inflammatory and anti-osteoporotic effects (5, 6). Vitamin E consists of 2 major isoforms: tocopherols and tocotrienols, each with four distinct analogues (alpha, beta, gamma, and delta). Tocopherols are saturated forms of vitamin E, and tocotrienols are the unsaturated forms, distinguishable by the three double bonds in the tails of tocotrienols (7). Studies showed that tocotrienol is superior for its antioxidant properties as well as increasing cells viability and proliferation (8, 9). The current project aim to evaluate the response of human periodontal ligament fibroblasts (HPdLF) upon exposure to various concentrations of tocotrienols rich fraction (TRF) conditioned medium

Contact Pattern of Alveolar Consonants in the Malay Consonants of Paralysis Subject using Electropalatography

Place of articulation plays an important part to produce different sounds. Besides the place of articulation, tongue is also an active articulator during a continuous speech. During the speech, the tongue moves around creating different sounds when it is placed at different place of articulation. The movement of tongue is controlled by muscles. The lack of muscle movement will produce inactive tongue movement. Paralysis is an example of the muscle weakness in a person resulting in difficulties to move. Paralysis may occur due to several factors including stroke and spinal cord injury (SCI). One of the indirect effects of paralysis is slurred speech and difficulty in speaking. This study aims to determine the contact pattern of five paralysed subjects during speech production of alveolar consonants in the Malay Language. The subjects had paralysis due to different aetiologies and with different medical history backgrounds. All participants were required to produce five single consonants; /d/, /t/, /l/, /n/ and /s/. The data recording was done in a studio laboratory with a soundproof system. The device used for detecting the tongue and hard palate contact in this study was electropalatography (EPG). Subjects were required to wear the artificial palate consists of 62 sensors to detect the tongue and hard palate contact. The speech contact was analysed using Articulate Assistant 1.18TM. The results were then compared with the average contact pattern of Malay speaker which had been obtained in the previous study. In conclusion, the subjects who had frequent treatments produced better articulation and the subjects with positive attitudes produced better articulation during the treatment process

In vitro investigations of bioactive glass scaffolds for dental tissue engineering

The regeneration of large bone and dental defects is hampered by the lack of remaining available tissue and the limited degree of vascularisation to support the healing process. Current treatment strategies using autologous tissue are inadequate for regenerative medicine. By contrast, the development of smart biomaterials that promote angiogenesis and bone deposition is gaining interest. This thesis describes the in vitro investigations of two bioactive glasses, namely strontium-containing bioactive glass (SrBG) and cobalt-containing bioactive glass (CoBG), for their potential use in the repair and regeneration of dental related structures. Strontium was incorporated into the bioactive glass (BG) structure by virtue of its dual role in promoting new bone formation and preventing osteoclast-mediated bone resorption. Cobalt is a known hypoxia-mimicking agent, and the incorporation of cobalt into the BG structure may also help create the hypoxic environment that benefits vascularisation during the regeneration of hard and soft tissue. Dental stem cells from permanent (dental pulp stem cells, DPSC) and deciduous teeth (stem cells from exfoliated deciduous tooth, SHED) were used in the current project since both appeared suitable for the regeneration of oral and dental related structures. Strontium-containing BG (SrBG) with 0%, 10% and 100% substitution of strontium for calcium were studied. Their dissolution profiles in culture medium (DMEM and RPMI) were assessed using inductively coupled plasma-optical emission spectroscopy (ICP-OES), and the dissolution products were tested on human osteosarcoma cells (Saos-2) and mouse monocyte cells (RAW264.7). At the selected SrBG powder to liquid ratio (SrBG in DMEM was 6.0 mg/ml, and SrBG in RPMI was 1.5 mg/ml), the bioactive glasses were non-cytotoxic. In addition, when dental pulp stem cells from the permanent and deciduous teeth (DPSC and SHED, respectively) were seeded on the 10% SrBG discs, both cell types had a higher proliferation rate when compared to those seeded on tissue culture plastic (Thermanox) after 21 days of culture. The use of DPSC and SHED as a source of stem cells for dental tissue engineering was investigated on cobalt-containing BG (CoBG). These glasses act as hypoxia-mimicking materials, a desirable property since hypoxia is known to enhance stem cell proliferation, stimulate VEGF secretion through the HIF-1 pathway, which help to improve vessel formation. First, the dissolution products from CoBG (0%, 1%, 2% and 4% cobalt for calcium substitution in mole percent) were incubated with the dental stem cells, and in vitro assays showed that the cobalt-containing BG-conditioned media had a dose-dependent effect on metabolic activity and proliferation. In addition, the CoBG succeeded in activating the hypoxia pathway, leading to VEGF secretion. The DPSC and SHED also secreted a substantial amount of collagen. Next, CoBG powder was incorporated into a biodegradable polymer, polycaprolactone (PCL), and three-dimensional cobalt-containing BG with PCL (CoBG/PCL) scaffolds were produced. The CoBG/PCL scaffolds also promoted the DPSC and human mesenchymal stem cells (hMSC) metabolic activity, and the cobalt released had no negative effect on cell survival. The CoBG/PCL scaffolds were also able to stimulate the hypoxia pathway and caused both DPSC and hMSC to secrete VEGF. Following the osteogenic induction of cells seeded on the CoBG/PCL scaffolds, there was lower ALP activity suggesting the cells remained undifferentiated when exposed to the hypoxia-mimicking CoBG. Although the DPSC and SHED were seeded only on the 10SrBG discs (10% of strontium substitution with calcium in BG), the results presented in this thesis demonstrate the potential of SrBG and CoBG scaffolds for dental tissue repair and regeneration. The CoBG as dissolution products from the CoBG powder and the incorporation of CoBG powder into scaffolds demonstrated activation of HIF pathway, which has promising potential for dental tissue repair and regeneration.Open Acces

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

Abstract 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

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

Variations in tooth size and arch dimensions in Malay schoolchildren

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

Bibliometric profiles of top 50 most cited articles on bioactive glass

Citation analysis of a certain publication acknowledges its impact on the scientific community. This study conducted a multivariate analysis of the top 50 most cited articles published on the field of Bioactive Glass. A systemic search was performed using the “All database” section of the Web of Science to retrieve the top 50 most cited original publications. The selected articles were then manually cross-matched with Elsevier Scopus and Google Scholar Database. Parameters such as article title, authorship, institution, country of publication, year, citation count, citation density, current citation index, and journal name were retrieved from Web of Science. Different ranges of citation numbers were retrieved for these publications in which 197-913 are from Web of Science, 209-962 are from Elsevier Scopus, and 269-1225 are from Google Scholar. A total of 153 authors contributed to this marked list, where Professor L.L. Hench contributed the highest number of articles (n=21). Imperial College London published the highest number of articles (n=21). In summary, this study provides a good scientometric picture of bioactive glass related publications, which illustrate the trend of biomaterials development over the years and suggests future scopes to the scientific community