Alloplasts are synthetic, inorganic, biocompatible bone substitutes that function as defect fillers to repair skeletal defects. The acceptance of these substitutes by host tissues is determined by the pore diameter and the porosity and inter-connectivity. This narrative review appraises recent developments, characterization, and biological performance of different synthetic materials for bone, periodontal, and dental tissue regeneration. They include calcium phosphate cements and their variants β-tricalcium phosphate (β-TCP) ceramics and biphasic calcium phosphates (hydroxyapatite (HA) and β-TCP ceramics), calcium sulfate, bioactive glasses and polymer-based bone substitutes which include variants of polycaprolactone. In summary, the search for synthetic bone substitutes remains elusive with calcium compounds providing the best synthetic substitute. The combination of calcium sulphate and β-TCP provides improved handling of the materials, dispensing with the need for a traditional membrane in guided bone regeneration. Evidence is supportive of improved angiogenesis at the recipient sites. One such product, (EthOss® Regeneration, Silesden UK) has won numerous awards internationally as a commercial success. Bioglasses and polymers, which have been used as medical devices, are still in the experimental stage for dental application. Polycaprolactone-TCP, one of the products in this category is currently undergoing further randomized clinical trials as a 3D socket preservation filler. These aforementioned products may have vast potential for substituting human/animal-based bone grafts.

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Despite the advances in cancer treatment, the 5-year survival rate for oral cancer has not changed significantly for the past 40 years and still remains among the worst of all anatomic sites. Gene expression microarrays have been used successfully in the identification of genetic alterations in cancer development, however, these have hitherto been limited by the need for specimens with good quality intact RNA. Here, we demonstrated the use of formalin-fixed paraffin-embedded tissues in microarray experiments to identify genes differentially expressed between cancerous and normal oral tissues. Forty-three tissue samples were macrodissected and gene expression analyses were conducted using the Illumina DASL assay. We report RNA yield of 2.4 and 0.8 microg/mm(3) from tumour and normal tissues, respectively and this correlated directly with the tissue volume used for RNA extraction. Using unsupervised hierarchical clustering, distinct gene expression profiles for tumour and normal samples could be generated, and differentially expressed genes could be identified. The majority of these genes were involved in regulation of apoptosis and cell cycle, metastasis and cell adhesion including BCL2A1, BIRC5, MMP1, MMP9 and ITGB4. Representative genes were further validated in independent samples suggesting that these genes may be directly associated with oral cancer development. The ability to conduct microarrays on formalin-fixed paraffin-embedded specimens represents a significant advancement that could open up avenues for finding genes that could be used as prognostication and predictive tools for cancer.

Introduction: Flexible denture is an alternative treatment modality for removable partial denture (RPD) that aid the retention by ensuring seal around the entire border of the denture. It is also referred as hypoallergenic denture especially for those who are allergic towards conventional acrylic denture which is the poly-methylmethacrylate monomer (PMMA) and metal (cobalt chromium). The flexible material exhibits lower flexural modulus than conventional type of baseplate material denture that makes it nearly unbreakable. Nowadays, there are a handful of different flexible materials in the dental market for the general dental practitioners to choose but somehow the studies on the properties of these different types of flexible materials are sparse. Objectives: The present study is to study the development of the flexible materials, the different type of flexible materials and their physical properties. Methods: From the limited article journals available, the authors have summarized the history, development and constituents of different type of flexible materials used in fabricating denture. Besides that, the authors also discussed about the indications, contraindications, advantages and disadvantages of the materials in denture constructions based on all the published researches available on this topic using published materials available in the dental library, University of Malaya and the databases (Science Direct, PubMed). Conclusion: Each flexible material has its pros and cons. Therefore, careful selection of material and understanding of the flexible dentures’ indications and contraindications are utmost importance to make sure the best treatment outcome. Hence, patients’ best interest and quality of life can be upheld.

Acrylic resin is commonly used to fabricate removable prostheses due to its adequate physical, mechanical properties and cost effectiveness. There has been continuous development of the materials to improve their properties and to widen its application in different clinical setting. To study the history development of the acrylic resin and elaborate on the properties of different types and the processing methods of acrylic resins used to fabricate denture base which are commercially available in the market. This would help the dental clinician in choosing the best material of choice. The authors have summarized the history, development and classification of different types of acrylic resins used in fabricating denture and processing methods based on all the published research available on this topic using published materials available in the Dental Library, University of Malaya and the database (Science Direct, PubMed). Every type of acrylic denture base material has its pros and cons. Therefore, careful selection of material and the processing method is crucial to ensure the best outcome for prosthodontic treatment. Hence, upholding the patients' best interest and improving their quality of life. www.adum.edu.my