Remineralization of Dentinal Lesions Using Biomimetic Agents: A Systematic Review and Meta-Analysis.

The objective of this article was to systematically provide an up-to-date review on the different methods of remineralizing human dentine using different biomimetic agents. The authors performed a systematic search within PubMed, Scopus, and Web of Science in addition to the grey literature in Google Scholar® using MeSH terms. The PICO question was P: human teeth dentinal sections; I: application of biomimetic remineralizing agents; C: other non-biomimetic approaches; O: extent of remineralization and physical properties of remineralized dentine. The initially identified studies were screened for titles and abstracts. Non-English articles, reviews, animal studies, studies involving the resin-dentine interface, and other irrelevant articles were then excluded. The other remaining full-text articles were retrieved. Bibliographies of the remaining articles were searched for relevant studies that could be included. A total of 4741 articles were found, and finally, 39 full-text articles were incorporated in the current systematic review. From these, twenty-six research studies used non-collagenous protein (NCP) analogs to biomineralize dentine, six studies used bioactive materials derived from natural sources, six studies used zinc hydroxyapatite, and one study used amelogenin peptide to induce hydroxyapatite formation on the surface of demineralized dentine. Additive effects of triclosan and epigenin were assessed when combined with commonly available NCPs. Overall, a moderate risk of bias was observed and, hence, the findings of the included studies could be acceptable. A meta-analysis of some similar studies was performed to assess the depth of remineralization and elastic modulus. Despite having high heterogeneity (I2 > 90), all the studies showed a significant improvement in biomimetic remineralization efficacy as compared to the control. All the included studies carried out a functional remineralization assessment and found a 90-98% efficacy in the extent of remineralization while the elastic modulus reached 88.78 ± 8.35 GPa, which is close to natural dentine. It is pertinent to note the limitations of these studies that have been carried out in vitro under controlled settings, which lack the effects of a natural oral environment. To conclude, the authors suggest that the biomimetic remineralization of dentine using NCP analogs, bioactive materials, and natural products carries significant potential in treating dentinal lesions; however, more long-term studies are needed to assess their clinical applications in vivo.

Effectiveness of Self-Assembling Peptide (P11-4) in Dental Hard Tissue Conditions: A Comprehensive Review.

The limitations on the use of fluoride therapy in dental caries prevention has necessitated the development of newer preventive agents. This review focusses on the recent and significant studies on P11-4 peptide with an emphasis on different applications in dental hard tissue conditions. The self-assembling peptide P11-4 diffuses into the subsurface lesion assembles into aggregates throughout the lesion, supporting the nucleation of de novo hydroxyapatite nanocrystals, resulting in increased mineral density. P11-4 treated teeth shows more remarkable changes in the lesion area between the first and second weeks. The biomimetic remineralisation facilitated in conjunction with fluoride application is an effective and non-invasive treatment for early carious lesions. Despite, some studies have reported that the P11-4 group had the least amount of remineralised enamel microhardness and a significantly lower mean calcium/phosphate weight percentage ratio than the others. In addition, when compared to a low-viscosity resin, self-assembling peptides could neither inhibit nor mask the lesions significantly. Moreover, when it is combined with other agents, better results can be achieved, allowing more effective biomimetic remineralisation. Other applications discussed include treatment of dental erosion, tooth whitening and dentinal caries. However, the evidence on its true clinical potential in varied dental diseases still remains under-explored, which calls for future cohort studies on its in vivo efficacy.

Early Odontogenic Differentiation of Dental Pulp Stem Cells Treated with Nanohydroxyapatite-Silica-Glass Ionomer Cement.

This study aimed to investigate the effects of nanohydroxyapatite-silica-glass ionomer cement (nanoHA-silica-GIC) on the differentiation of dental pulp stem cells (DPSCs) into odontogenic lineage. DPSCs were cultured in complete Minimum Essential Medium Eagle-Alpha Modification (α-MEM) with or without nanoHA-silica-GIC extract and conventional glass ionomer cement (cGIC) extract. Odontogenic differentiation of DPSCs was evaluated by real-time reverse transcription polymerase chain reaction (rRT-PCR) for odontogenic markers: dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), osteocalcin (OCN), osteopontin (OPN), alkaline phosphatase (ALP), collagen type I (COL1A1), and runt-related transcription factor 2 (RUNX2) on day 1, 7, 10, 14, and 21, which were normalized to the house keeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Untreated DPSCs were used as a control throughout the study. The expressions of DSPP and DMP1 were higher on days 7 and 10, that of OCN on day 10, those of OPN and ALP on day 14, and that of RUNX2 on day 1; COL1A1 exhibited a time-dependent increase from day 7 to day 14. Despite the above time-dependent variations, the expressions were comparable at a concentration of 6.25 mg/mL between the nanoHA-silica-GIC and cGIC groups. This offers empirical support that nanoHA-silica-GIC plays a role in the odontogenic differentiation of DPSCs.

Molecular Detection of Glycophorins A and B Variant Phenotypes and their Clinical Relevance.

Crossover or conversion between the homologous regions of glycophorin A (GYPA) and glycophorin B (GYPB) gives rise to several different hybrid glycophorin genes encoding a number of different glycophorin variant phenotypes which bear low prevalence antigens in the MNS blood group system. GP.Mur is the main glycophorin variant phenotype which causes hemolytic transfusion reaction (HTR) and hemolytic disease of the fetus and newborn (HDFN) in East and Southeast Asians. The detection of glycophorin variant phenotypes using serological methods is limited to phenotyping reagents that are not commercially available. Moreover, the red blood cells used for antibody identification are usually of the GP.Mur phenotype. The current Polymerase Chain Reaction (PCR)-based methods and loop-mediated isothermal amplification (LAMP) are available alternatives to phenotyping that allow for the specific detection of glycophorin variant phenotypes. This review highlights the molecular detection method for glycophorins A and B variant phenotypes and their clinical relevance.

White mineral trioxide aggregate mixed with calcium chloride dihydrate: chemical analysis and biological properties

OBJECTIVES: This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate (CaCl₂·2H₂O), compared to that of WMTA. MATERIALS AND METHODS: Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazol-diphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively. RESULTS: Results showed that the addition of CaCl₂·2H₂O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. CONCLUSIONS: The addition of CaCl₂·2H₂O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.

Biological Interaction Between Human Gingival Fibroblasts and Vascular Endothelial Cells for Angiogenesis: A Co-culture Perspective

Advancement in cell culture protocols, multidisciplinary research approach, and the need of clinical implication to reconstruct damaged or diseased tissues has led to the establishment of three-dimensional (3D) test systems for regeneration and repair. Regenerative therapies, including dental tissue engineering, have been pursued as a new prospect to repair and rebuild the diseased/lost oral tissues. Interactions between the different cell types, growth factors, and extracellular matrix components involved in angiogenesis are vital in the mechanisms of new vessel formation for tissue regeneration. In vitro pre-vascularization is one of the leading scopes in the tissue-engineering field. Vascularization strategies that are associated with co-culture systems have proved that there is communication between different cell types with mutual beneficial effects in vascularization and tissue regeneration in two-dimensional or 3D cultures. Endothelial cells with different cell populations, including osteoblasts, smooth muscle cells, and fibroblasts in a co-culture have shown their ability to advocate pre-vascularization. In this review, a co-culture perspective of human gingival fibroblasts and vascular endothelial cells is discussed with the main focus on vascularization and future perspective of this model in regeneration and repair.

Effect of perivitelline fluid from horseshoe crab on the expression of COL1A1 in dental pulp stem cells

Perivitelline fluid, extracted from the fertilized eggs of horseshoe crabs, has been reported to play a vital role in supporting embryogenesis as well as cell proliferation. The present study aims to evaluate the effect of PVF on the expression of COL1A1 in human dental pulp stem cells (DPSCs). The cells were grouped into two; untreated (control) and treated with a single dose of PVF (0.019 mg/ml). Gene expression was quantified for COL1A1 on day 1, 3 and 7 using reverse transcriptase PCR. The expression of COL1A1 on day 3 of treated group with PVF was the highest though there was a decline of COL1A1 expression on day 7. Mann Whitney test was utilized to determine the significance of COL1A1 expression between treated and untreated groups. Significant difference in the expression of COL1A1 was observed between the treated and untreated groups on day 3 though there was no significance in the expression on day 7. The present study indicates that PVF may have the potential to increase cell proliferation in human DPSCs.

Angiogenic Potential of Extracellular Matrix of Human Amniotic Membrane

Combination between tissue engineering and other fields has brought an innovation in the area of regenerative medicine which ultimate aims are to repair, improve, and produce a good tissue construct. The availability of many types of scaffold, both synthetically and naturally have developed into many outstanding end products that have achieved the general objective in tissue engineering. Interestingly, most of this scaffold emulates extracellular matrix (ECM) characteristics. Therefore, ECM component sparks an interest to be explored and manipulated. The ECM featured in human amniotic membrane (HAM) provides a suitable niche for the cells to adhere, grow, proliferate, migrate and differentiate, and could possibly contribute to the production of angiogenic micro-environment indirectly. Previously, HAM scaffold has been widely used to accelerate wound healing, treat bone related and ocular diseases, and involved in cardiovascular repair. Also, it has been used in the angiogenicity study, but with a different technical approach. In addition, both side of HAM could be used in cellularised and decellularised conditions depending on the objectives of a particular research. Therefore, it is of paramount importance to investigate the behavior of ECM components especially on the stromal side of HAM and further explore the angiogenic potential exhibited by this scaffold.

Effects of different processing methods of human amniotic membrane on the quality of extracted RNA

The aim of this study was to determine the efficiency of different human amniotic membrane (HAM) processing methods on the concentration, purity and integrity of RNA. Two different techniques (Technique 1 and Technique 2) were employed for the processing of HAM, which differed in terms of washing solution, sample storage conditions and processing time. Based on preservation of HAM, three groups were formed under each technique. In Technique 1, the groups were fresh frozen 1 (F1), glycerol preserved (GP) and gamma irradiated glycerol preserved (IGP); where else in Technique 2, the groups were fresh frozen 2 (F2), 50% glycerol/Dulbecco’s modified Eagle medium (DMEM) cryopreserved HAM diluted with phosphate buffered saline (GB) and 50% glycerol/DMEM cryopreserved HAM diluted with diethylprocarbonate water (GD). Total RNA was extracted from the samples and their concentration, purity and integrity were examined. The F2 sample of which there was no pre-washing step and involved direct sample storage at -80ºC, shorter processing time and chilled processing conditions had yielded better quality of RNA compared to the others.

Keloid Scarring: Understanding the Genetic Basis, Advances, and Prospects

Keloid disease is a fibroproliferative dermal tumor with an unknown etiology that occurs after a skin injury in genetically susceptible individuals. Increased familial aggregation, a higher prevalence in certain races, parallelism in identical twins, and alteration in gene expression all favor a remarkable genetic contribution to keloid pathology. It seems that the environment triggers the disease in genetically susceptible individuals. Several genes have been implicated in the etiology of keloid disease, but no single gene mutation has thus far been found to be responsible. Therefore, a combination of methods such as association, gene-gene interaction, epigenetics, linkage, gene expression, and protein analysis should be applied to determine keloid etiology.

Genotoxicity assessment of locally produced dental nanocomposite using Comet assay

The aim of this study was to determine the genotoxicity of a locally produced nanocomposite by Universiti Sains Malaysia, Malaysia using Comet assay. Stem cells from human exfoliated deciduous teeth (SHED) were treated with the nanocomposite at five different concentrations (0.006, 0.0125, 0.025, 0.05, and 0.1 mg/ml) along with concurrent negative (medium alone) and positive control (zinc sulfate heptahydrate) and incubated at 37°C for 24 hours in an incubator at 5% CO2. The tail moment was used to assess the extent of DNA damage. The tail moment for the group of SHED treated with nanocomposite (for all the five different concentrations) was not statistically significant as compared to the negative control, suggesting that the locally produced dental nanocomposite did not induce any DNA damage. Hence, it can be concluded that the locally produced nanocomposite is non-genotoxic on stem cells from human exfoliated deciduous teeth.

Cytogenetics: Past, Present And Future

Fifty years have elapsed since the discovery of the number of human chromosomes in 1956. Newer techniques have been developed since then, ranging from the initial conventional banding techniques to the currently used molecular array comparative genomic hybridisation. With a combination of these conventional and molecular techniques, cytogenetics has become an indispensable tool for the diagnosis of various genetic disorders, paving the way for possible treatment and management. This paper traces the history and evolution of cytogenetics leading up to the current state of technology.