Modifications in Glass Ionomer Cements: Nano-Sized Fillers and Bioactive Nanoceramics

Minimally invasive judgement calls: managing compromised first permanent molars in children

This paper aims to update the reader on how minimally invasive (MI) techniques may be used to improve the longevity of carious or defective/compromised first permanent molars (cFPMs) in young children. Clinical and radiographic diagnosis and the prognostic factors will be discussed in view of recent studies showing that these teeth can be kept in function and have an improved prognosis as the child gets older. Clinical protocols for their care, based on the latest evidence and techniques for MI restorations, together with longevity information of possible restorative options, are described. This paper also explores the rationale behind enforced extractions and related morbidity, in order to help oral healthcare practitioners to determine the optimal management of these key elements in the dentition for the benefit of the patients.

Effect of water aging on the anti-biofilm properties of glass ionomer cement containing fluoro-zinc-silicate fillers

A previous study has reported that a novel fluoro-zinc-silicate glass ionomer cement (Caredyne Restore) showed superior anti-biofilm effects by interfering with bacterial adhesion. However, the active ions may degrade with time. This study aimed to assess the valid anti-biofilm effects of Caredyne Restore after being aged by water immersion for 3 weeks. Streptococcus mutans biofilm was allowed to grow on the surface before and after water aging for 24 h using a modified Robbins device flow-cell system. The results showed water aging promoted biofilm formation. Insufficient amount of fluoride and zinc ions were released from Caredyne Restore after water aging under neutral pH condition. An acidic pH is needed to exert effective anti-biofilm properties. As the release of active ions from Caredyne Restore will gradually decrease after the restoration,  the restoration may not prevent biofilm formation after 3 weeks while neutral pH is maintained by the buffering capacity of saliva.

Physical Properties of Glass Ionomer Cement Containing Pre-Reacted Spherical Glass Fillers

The aim of this study was to assess the effect of different commercial liquid phases (Ketac, Riva, and Fuji IX) and the use of spherical pre-reacted glass (SPG) fillers on cement maturation, fluoride release, compressive (CS) and biaxial flexural strength (BFS) of experimental glass ionomer cements (GICs). The experimental GICs (Ketac_M, Riva_M, FujiIX_M) were prepared by mixing SPG fillers with commercial liquid phases using the powder to liquid mass ratio of 2.5:1. FTIR-ATR was used to assess the maturation of GICs. Diffusion coefficient of fluoride (DF) and cumulative fluoride release (CF) in deionized water was determined using the fluoride ion specific electrode (n=3). CS and BFS at 24 h were also tested (n=6). Commercial GICs were used as comparisons. Riva and Riva_M exhibited rapid polyacrylate salt formation. The highest DF and CF were observed with Riva_M (1.65x10-9 cm2/s) and Riva (77 ppm) respectively. Using SPG fillers enhanced DF of GICs on average from ~2.5x10-9 cm2/s to ~3.0x10-9 cm2/s but reduced CF of the materials on average from ~51 ppm to ~42 ppm. The CS and BFS of Ketac_M (144 and 22 MPa) and Fuji IX_M (123 and 30 MPa) were comparable to commercial materials. Using SPG with Riva significantly reduced CS and BFS from 123 MPa to 55 MPa and 42 MPa to 28 MPa respectively. The use of SPG fillers enhanced DF but reduced CF of GICs. Using SPG with Ketac or Fuji IX liquids provided comparable strength to the commercial materials.

Current aspects and prospects of glass ionomer cements for clinical dentistry

Glass ionomer cement (GIC) is a tailor-made material that is used as a filling material in dentistry. GIC is cured by an acid-base reaction consisting of a glass filler and ionic polymers. When the glass filler and ionic polymers are mixed, ionic bonds of the material itself are formed. In addition, the extra polymer anion reacts with calcium in enamel or dentin to increase adhesion to the tooth tissue. GICs are widely used as adhesives for artificial crowns or orthodontic brackets, and are also used as tooth repair material, cavity liner, and filling materials. In this review, the current status of GIC research and development and its prospects for the future have been discussed in detail.

Commercially Available Fluoride-Releasing Restorative Materials: A Review and a Proposal for Classification

Resin composite and glass ionomer cement (GIC) are the most commonly used dental materials to perform direct restorations. Both have specific characteristics that explain their popularity and their limits. More than 20 years ago, the first attempt (followed by others) to combine the advantages of these two families was performed with compomers, but it was not very successful. Recently, new formulations (also called 'smart materials') with claimed ion release properties have been proposed under different family names, but there are few studies on them and explanations of their chemistries. This comprehensive review aims to gather the compositions; the setting reactions; the mechanical, self-adhesive, and potential bulk-fill properties; and the ion release abilities of the large existing families of fluoride-releasing restorative materials and the new restorative materials to precisely describe their characteristics, their eventual bioactivities, and classify them for an improved understanding of these materials. Based on this work, the whole GIC family, including resin-modified and highly viscous formulations, was found to be bioactive. Cention N (Ivoclar Vivadent, AG, Schaan, Lietschentein) is the first commercially available bioactive resin composite.

Smart injectable self-setting bioceramics for dental applications

A thermo-responsive injectable bioactive glass (BAG) that has the ability to set at body temperature was prepared using pluronic F127 and hydroxypropyl methylcellulose as the carrier. The injectable composite has the advantage to fill irregular shape implantation sites and quick setting at body temperature. The structural and morphological analysis of injectable BAG before and after setting was done by using Fourier Transform Infrared spectroscopy (FTIR), and Scanning Electron Microscope (SEM). The effect of an ultrasonic scaler for a quick setting of injectable BAG was also investigated. The ultrasonic scaler sets the BAG formulation three-folds faster than at body temperature and homogenized the dispersion. The in vitro bio-adhesion was studied in the bovine tooth in both artificial saliva and deionized water for periodic time intervals, i.e., day 7, 30, 90, and 180, which confirmed the apatite layer formation. The mineral density analysis was used to differentiate the newly formed apatite with tooth apatite. In the MTT assay, the experimental material showed continuous proliferation and cell growth. This indicated that injectable hydrogel promoted cell growth, facilitated proliferation, and had no cytotoxic effect. The SEM and micro-CT results (performed after in vitro bioactivity testing) showed that the injectable BAG had the ability to regenerate dentin, hence this material has the potential to be used for dental and biomedical applications including tooth and bone regeneration in minimally invasive procedures in future.

Polymeric and inorganic nanoscopical antimicrobial fillers in dentistry

Failure of dental treatments is mainly due to the biofilm accumulated on the dental materials. Many investigations have been conducted on the advancements of antimicrobial dental materials. Polymeric and inorganic nanoscopical agents are capable of inhibiting microorganism proliferation. Applying them as fillers in dental materials can achieve enhanced microbicidal ability. The present review provides a broad overview on the state-of-the-art research in the field of antimicrobial fillers which have been adopted for incorporation into dental materials over the last 5 years. The antibacterial agents and applications are described, with the aim of providing information for future investigations. STATEMENT OF SIGNIFICANCE: Microbial infection is the primary cause of dental treatment failure. The present review provides an overview on the state-of-art in the field of antimicrobial nanoscopical or polymeric fillers that have been applied in dental materials. Trends in the biotechnological development of these antimicrobial fillers over the last 5 years are reviewed to provide a backdrop for further advancement in this field of research.

Bioactive Glass Applications in Dentistry

At present, researchers in the field of biomaterials are focusing on the oral hard and soft tissue engineering with bioactive ingredients by activating body immune cells or different proteins of the body. By doing this natural ground substance, tissue component and long-lasting tissues grow. One of the current biomaterials is known as bioactive glass (BAG). The bioactive properties make BAG applicable to several clinical applications involving the regeneration of hard tissues in medicine and dentistry. In dentistry, its uses include dental restorative materials, mineralizing agents, as a coating material for dental implants, pulp capping, root canal treatment, and air-abrasion, and in medicine it has its applications from orthopedics to soft-tissue restoration. This review aims to provide an overview of promising and current uses of bioactive glasses in dentistry.

Cell physiological effects of glass ionomer cements on fibroblast cells

The cytotoxicity of glass ionomer cements (GICs) was investigated using a novel, cost-effective, easy-to-perform and standardized test. GIC rings were made using in-house designed, custom-made moulds under sterile conditions; 10 with Fuji Equia and 10 with Fuji Triage capsules, placed in direct contact with primary human gingival fibroblasts (HGF) and immortalized human fibroblasts (HFF1). On day 1, 4, 14 and 21, an AlamarBlue® (resazurin) assay was completed towards determining the effects of the GICs on metabolic activities of the cells, whilst cell morphology was examined by light microscopy. The influence of the compounds released from the GIC rings on cell physiological effects (viability, proliferation and adhesion) during 24 h incubation was further investigated by impedimetry. Result trends obtained from this battery of techniques were complementary. At 100 v/v% concentration, the released compounds from Equia were strongly cytotoxic, while at lower concentration (0, 4, 20 v/v%) they were not cytotoxic. In contrast, Triage elicited only slightly transient cytotoxicity. The method proposed has been proved as being efficient, reliable and reproducible and may be useful in quick testing of the cytotoxicity of similar biomaterials by using an immortalized cell line.

Modifications of Glass Ionomer Cement Powder by Addition of Recently Fabricated Nano-Fillers and Their Effect on the Properties: A Review

The aim of this article is to provide a brief insight regarding the recent studies and their recommendations related to the modifications to glass ionomer cement (GIC) powder in order to improve their properties. An electronic search of publications was made from the year 2000 to 2018. The databases included in the current study were EBSCOhost, PubMed, and ScienceDirect. The inclusion criteria for the current study include publication with abstract or full-text articles, original research, reviews or systematic reviews, in vitro, and in vivo studies that were written in English language. Among these only articles published in peer-reviewed journals were included. Articles published in other languages, with no available abstract and related to other nondentistry fields, were excluded. A detailed review of the recent materials used as a filler phase in GIC powder has revealed that not all modifications produce beneficial results. Recent work has demonstrated that modification of GIC powder with nano-particles has many beneficial effects on the properties of the material. This is due to the increase in surface area and surface energy, along with better particle distribution of the nano-particle. Therefore, more focus should be given on nano-particle having greater chemical affinity for GIC matrix as well as the tooth structure that will enhance the physicochemical properties of GIC.

Effect of a novel glass ionomer cement containing fluoro-zinc-silicate fillers on biofilm formation and dentin ion incorporation

OBJECTIVES

This study is aimed at evaluating the effect of a new glass ionomer cement (GIC) containing fluoro-zinc-silicate fillers on biofilm formation and ion incorporation.

MATERIALS AND METHODS

Streptococcus mutans biofilms were developed on two GIC materials: Caredyne Restore (CD) and Fuji VII (FJ); and hydroxyapatite (HA) for 24 h at 37 °C using a flow cell system. The morphological structure and bacterial viability were analyzed using a confocal laser scanning microscopy. Bacterial adhesion during the initial 2 h was also assessed by viable cell counting. To study the ion incorporation, restored cavities prepared on the root surfaces of human incisors were subjected to the elemental mapping of the zinc and fluoride ions in the GIC-dentin interface using a wavelength-dispersive X-ray spectroscopy electron probe microanalyzer.

RESULTS

Morphological observations revealed that biofilm formation in the CD group was remarkably inhibited compared with the HA and FJ groups, exhibiting sparse, thinner biofilm clusters. The microorganisms adhering to the CD group were significantly inhibited, revealing 2.9 ± 0.4 for CD, 4.9 ± 0.2 for FJ, and 5.4 ± 0.4 log colony-forming units (CFU) for HA. The CD zinc ion incorporation depth was 72.2 ± 8.0 μm. The fluoride penetration of CD was three times deeper than that of FJ; this difference was statistically significant (p < 0.05).

CONCLUSIONS

Enhanced by the incorporation of zinc and fluoride ions, the new GIC inhibited biofilm formation by interfering with bacterial adhesion.

CLINICAL RELEVANCE

A novel GIC comprised of fluoro-zinc-silicate fillers may improve clinical outcomes, such as root caries and minimally invasive dentistry.

Mechanical Properties of High Viscosity Glass Ionomer and Glass Hybrid Restorative Materials

OBJECTIVES

to determine the mechanical properties of hybrid and high-viscosity glass ionomer cements. Compressive strength and hardness of three glass ionomer cements (GIC) were measured: Ketac ™ Universal Aplicap ™, EQUIA Fil® and EQUIA FORTE Fil®, and the SEM sample analysis were performed.

MATERIALS AND METHODS

The samples for measuring the compressive strength were prepared using silicone molds with standard dimensions of 6 mm x 4 mm and stored in deionized water for five days, while the samples for hardness measurement were prepared using Teflon molds with a cylindrical opening in the middle, dimensions 2 mm in height and 5 mm in width. For each material, one sample was made (n = 1) and stored in deionized water at 37ºC for 25 days. A representative sample of each material was analyzed using SEM. For the comparison of obtained values, the ANOVA test was used, while Tukey test was used for the multiple comparison.

RESULTS

There were no significant differences between the compressive strength of the three tested materials (p <0.05). The hardness values were: 157 HV0,2 for Ketac ™ Universal Aplicap ™, 47 HV0,2 for EQUIA Fil® and 39 HV0,2 for EQUIA FORTE Fil®, respectively, and were significantly different, implying that Ketac ™ Universal Aplicap ™ has much higher hardness values than the other materials tested. SEM sample analysis revealed similar fracture modes of the tested materials.

CONCLUSION

It was concluded that there were no statistically significant differences in compressive strength and fracture modes between the tested materials, while Ketac ™ Universal Aplicap ™ hardness results were significantly higher than the ones measured for EQUIA Fil® and EQUIA FORTE Fil®.

The Biological Evaluation of Conventional and Nano-Hydroxyapatite-Silica Glass Ionomer Cement on Dental Pulp Stem Cells: A Comparative Study

BACKGROUND

Despite their lower strength, glass ionomer cements (GICs) are widely used as restorative materials because of their anti-cariogenic properties, direct adhesion to tooth structure and good biocompatibility. Recently, the addition of nano-hydroxyapatite (nano-HA)-silica to conventional GIC (cGIC) has been shown to improve the strength of cGIC. However, the biocompatibility and cell attachment properties of this material are unknown.

AIMS

This study aims to evaluate and compare the cytotoxicity and cell attachment properties of cGIC and nano-HA-silica-GIC on dental pulp stem cells (DPSCs).

METHODS AND MATERIALS

Material extracts of nano-HA-silica-GIC and cGIC were prepared into seven serial dilutions and applied to 96 well plates seeded with DPSCs. After 72 h, the cell viability was determined using MTT assay. The DPSCs cell attachment properties were examined under scanning electron microscope (SEM) after 24 and 72 h. Kruskal-Wallis test was used to analyse the data for MTT assay (P < 0.05). SEM images of cell attachment properties were also described.

RESULTS

Nano-HA-silica-GIC and cGIC was shown to be slight to non-cytotoxic at all concentrations, except 200 mg/ml. Moderate cytotoxicity has been observed at 200 mg/ml concentration where nano-HA-silica-GIC and cGIC revealed cell viability values of 44.38 and 42.15%, respectively. Nano-HA-silica-GIC demonstrated better cell viability values than cGIC at all concentrations except for 6.25 and 12.5 mg/ml. Nevertheless, the results were not statistically significant (P > 0.05). SEM examination revealed the increasing numbers of DPSCs attached to both groups with prominent filopodia, especially after 72 h.

CONCLUSIONS

Nano-HA-silica-GIC exhibited good biocompatibility which is comparable to cGIC and favoured the attachment of DPSCs.

Characteristics of chitosan-modified glass ionomer cement and their effects on the adhesion and proliferation of human gingival fibroblasts: an in vitro study

This study explores the possibility of adhering gingival tissue to a root surface that was restored with chitosan (CS)-modified glass ionomer cement (GIC) in the case of gingival recessions associated with root caries, which provides a theoretical basis for clinical application at the cellular level. The specimens were mixed after integrating 1, 2, and 4 wt% CS into the GIC fluid. The characteristics and cytocompatibility were then examined. As more CS was incorporated into the GIC fluid, the mechanical properties and cytocompatibility of chitosan-modified glass ionomer cement (CS-GIC) first improved but then reduced. Under scanning electron microscopy, microcracks were observed on the surface of all materials, but the fewest microcracks were observed on the surface of 2 wt% CS-GIC. The compressive strength of 2 wt% CS-GIC was significantly higher than that of the other groups at 5 days (P < 0.05) and the addition of chitosan didn't change the basic fracture mode of materials. Additionally, the integration 2 wt% CS into GIC can obviously reduce acidity of the original GIC (P < 0.01) when using extracts with concentrations of 100 and 50%. The Cell Counting Kit-8 assay and adhesion and proliferation of human gingival fibroblasts (HGFs) on the surface of the materials indicated that 2 wt% CS-GIC presented better cytocompatibility and was more suitable for the growth of HGFs. In summary, 2 wt% CS-GIC could be considered as a potential root filling material to allow the adhesion and growth of gingival tissue.

Contraction and Hydroscopic Expansion Stress of Dental Ion-Releasing Polymeric Materials

Ion-releasing polymeric restorative materials seem to be promising solutions, due to their possible anticaries effect. However, acid functional groups (monomers) and glass filler increase hydrophilicity and, supposedly, water sorption. The purpose of the study was to evaluate the influence of water sorption of polymeric materials on the stress state at the restoration-tooth interface. Beautifil Bulk Fill Flow, Beautifil Flow Plus F00, Beautifil Flow F02, Dyract eXtra, Compoglass Flow, Ionosit, Glasiosite, TwinkiStar, Ionolux and Fuji II LC were used for the study. The stress state was measured using photoelastic analysis after: 0.5, 24, 72, 96, 168, 240, 336, 504, 672, 1344 and 2016 h. Moreover, water sorption, solubility and absorption dynamic were assessed. The water sorption, solubility and absorption dynamic of ion-releasing restorative materials are material dependent properties. The overall results indicated that the tested restorative materials showed significant stress decrease. The total reduction in contraction stress and water expansion stress was not observed for materials with low value of water sorption (Beautifil Bulk Fill, Dyract eXtra, Glasionosit and Twinky Star). The photoelastic method turned out to be inadequate to evaluate stress changes of resin modified glass-ionomer cement (RMGI, Fuji II LC and Ionolux).

Effects of deformation rate variation on biaxial flexural properties of dental resin composites

Objectives

This study aimed to determine the biaxial flexural strength (BFS) of resin composite materials at distinct deformation rates.

Methods

Two micro-hybrid [Filtek Z100™ Restorative (Z100), Filtek™ Z250 (Z250)] and two nano-filled [Filtek™ Supreme XT Body (FSB), Filtek™ Supreme Translucent (FST)] composite resins were selected. Disc-shaped (12 × 1 mm) specimens were fabricated using nylon split moulds. Bar-shaped specimens (25 × 2 × 2 mm) were fabricated from each material to determine the flexural modulus. The specimens were tested for BFS and flexural modulus under dry and wet conditions after 1, 13, and 52 weeks.

Results

The highest BFS was recorded for Z250 (162 ± 19 MPa), followed by FST (154 ± 16 MPa), Z100 (150 ± 18 MPa), and FSB (136 ± 18 MPa). The materials exhibited a clear trend of increase in BFS with deformation rate. Following immersion for 1 week, the BFS was 126 ± 18 MPa for Z100, and 124 ± 17 MPa for Z250, which were higher than those of FSB (99 ± 16 MPa) and FST (115 ± 19 MPa) under comparable conditions. There was a remarkable reduction in the flexural moduli of the specimens immersed for 1 week compared to those of the dry specimens: Z100 (from 18.3 ± 1.2 GPa for dry specimen to 15.7 ± 0.8 GPa after immersion for 1 week), Z250 (from 16.7 ± 0.8 GPa to 13.3 ± 1.4 GPa), FSB (from 13.7 ± 0.6 GPa to 11.0 ± 2.1 GPa) and FST (from 12.7 ± 2.3 GPa to 10.4 ± 1.0 GPa).

Conclusion

This study concludes that the BFS and flexural moduli of resin-based dental restoratives decline when they are immersed in an aqueous medium until saturation with water. However, after equilibrium is established, the immersion medium does not affect the restorative materials further. Variations in deformation rate did not have a significant effect on the BFS of resin-based dental restoratives.

The effect of dentine pre-treatment using bioglass and/or polyacrylic acid on the interfacial characteristics of resin-modified glass ionomer cements

OBJECTIVE

To evaluate the effect of load-cycle aging and/or 6 months artificial saliva (AS) storage on bond durability and interfacial ultramorphology of resin-modified glass ionomer cement (RMGIC) applied onto dentine air-abraded using Bioglass 45S5 (BAG) with/without polyacrylic acid (PAA) conditioning.

METHODS

RMGIC (Ionolux, VOCO) was applied onto human dentine specimens prepared with silicon-carbide abrasive paper or air-abraded with BAG with or without the use of PAA conditioning. Half of bonded-teeth were submitted to load cycling (150,000 cycles) and half immersed in deionised water for 24 h. They were cut into matchsticks and submitted immediately to microtensile bond strength (μTBS) testing or 6 months in AS immersion and subsequently μTBS tested. Results were analysed statistically by two-way ANOVA and Student-Newman-Keuls test (α = 0.05). Fractographic analysis was performed using FE-SEM, while further RMGIC-bonded specimens were surveyed for interfacial ultramorphology characterisation (dye-assisted nanoleakage) using confocal microscopy.

RESULTS

RMGIC applied onto dentine air-abraded with BAG regardless PAA showed no significant μTBS reduction after 6 months of AS storage and/or load cycling (p > 0.05). RMGIC-dentine interface showed no sign of degradation/nanoleakage after both aging regimens. Conversely, interfaces created in PAA-conditioned SiC-abraded specimens showed significant reduction in μTBS (p < 0.05) after 6 months of storage and/or load cycling with evident porosities within bonding interface.

CONCLUSIONS

Dentine pre-treatment using BAG air-abrasion might be a suitable strategy to enhance the bonding performance and durability of RMGIC applied to dentine. The use of PAA conditioner in smear layer-covered dentine may increase the risk of degradation at the bonding interface.

CLINICAL SIGNIFICANCE

A combined dentine pre-treatment using bioglass followed by PAA may increase the bond strength and maintain it stable over time. Conversely, the use of PAA conditioning alone may offer no significant contribute to the immediate and prolonged bonding performance.

Effect of a calcium chloride solution treatment on physical and mechanical properties of glass ionomer cements

This paper details a novel method to improve wear resistance of dental glass ionomer cement (GIC) restorations. The purpose of this in vitro study was to evaluate the effect of a calcium chloride (CaCl₂) solution treatment on surface hardness, surface roughness, compressive strength, water sorption and solubility of three conventional glass ionomer cements (GICs). Additionally, the changes of the Ca composition and morphology of the surface of the tested GICs were also investigated. The experimental groups of the study were: Group 1 (control) specimens after mixing were left in the mold to set without any treatment for 5 min; Group 2 specimens were left in the mold to set for 5 min and then each specimen was immersed in 10 ml of 42.7 wt% CaCl₂ solution for 60 s. Statistical analysis was performed using one-way ANOVA and Tukey post hoc tests (a = 0.05). Calcium chloride solution treatment increased surface hardness of the GICs compared to control groups (P < 0.05), while surface roughness and compressive strength did not change after the treatment (P > 0.05). Reduction in water sorption and solubility was detected but not in all CaCl₂ solution-treatment groups. No alterations were observed in surface morphology of the GICs, while surface calcium composition was increased after the treatment (P < 0.05). The use of a CaCl₂ solution immediately after initial setting of GICs may be advantageous for some properties of the materials and possibly leads to improved prognosis and wear resistance of their restorations.

Comparative abrasive wear resistance and surface analysis of dental resin-based materials

OBJECTIVE

The objective of this study was to assess the surface properties (microhardness and wear resistance) of various composites and compomer materials. In addition, the methodologies used for assessing wear resistance were compared.

MATERIALS AND METHODS

This study was conducted using restorative material (Filtek Z250, Filtek Z350, QuiXfil, SureFil SDR, and Dyract XP) to assess wear resistance. A custom-made toothbrush simulator was employed for wear testing. Before and after wear resistance, structural, surface, and physical properties were assessed using various techniques.

RESULTS

Structural changes and mass loss were observed after treatment, whereas no significant difference in terms of microhardness was observed. The correlation between atomic force microscopy (AFM) and profilometer and between wear resistance and filler volume was highly significant. The correlation between wear resistance and microhardness were insignificant.

CONCLUSIONS

The AFM presented higher precision compared to optical profilometers at a nanoscale level, but both methods can be used in tandem for a more detailed and precise roughness analysis.

Propolis: A natural biomaterial for dental and oral healthcare

The field of health has always emphasised on the use of natural products for curing diseases. There are varieties of natural products (such as silk, herbal tea, chitosan) used today in the biomedical application in treating a large array of systemic diseases. The natural product "Propolis" is a non-toxic resinous material having beneficial properties such as antimicrobial, anticancer, antifungal, antiviral and anti-inflammatory; hence gain the attention of researchers for its potential for bio-dental applications. The study aims to explore the properties and chemistry of propolis concerning biomedical and dental applications. In addition, status and scope of propolis for current and potential future in bio-dental applications have been discussed. This review gives an insight to the reader about the possible use of propolis in modern-day dentistry.

Influence of Energy Beverages on the Surface Texture of Glass lonomer Restorative Materials

BACKGROUND AND OBJECTIVE

The objective of the study was to find whether energy beverages have an erosive effect, leading to a risk in the clinical performance of glass ionomer restorative materials.

AIM

This study evaluated the influence of energy beverages on the surface texture of glass ionomer restorative materials.

MATERIALS AND METHODS

Glass ionomer materials used were Ionofil Plus AC, GC EQUIA, and Ketac Molar; energy beverages are Code Red, Red Bull, and Power Horse. Specimens prepared were discs of 8 mm diameter and 3 mm thickness; specimens from each material were evaluated following aging with Code Red, Red Bull, and Power Horse energy beverages. Distilled water was used as a control. The surface roughness (Ra) was assessed by surface scanning interferometry. The surface roughness values (ΔRa and Ra) were measured for each specimen. The data were analyzed statistically using multiple repeated measures [analysis of variance (ANOVA)] and paired data t-test (p < 0.05 was considered as the significance level).

RESULTS

The surface roughness (ΔRa and Ra) values before and after aging using Code Red, Red Bull, and Power Horse energy beverages differ significantly for all the materials regardless of the immersion time (p < 0.05). All the materials showed roughness changes after immersion periods of 1 day, 1 week, and 1 month.

CONCLUSION

It can be concluded that all energy beverage solutions used in this study had an adverse effect on the surface roughness degradation of the tested glass ionomers with increasing immersion time.

CLINICAL SIGNIFICANCE

Energy beverages have an erosive effect on glass ionomer, which influences the clinical importance of the material; it also has anticarious property because it releases the fluoride.

The Effect of Preventive Agents (Mouthwashes/Gels) on the Color Stability of Dental Resin-Based Composite Materials

The color of dental restorative material should be maintained throughout its functional lifetime in an oral environment. However, the frequent use of mouthwash may affect the color stability of these composite restorations. The aim of this study is to assess the effects of using various mouthwashes on the color stability of various dental restorative composite materials. For this purpose, four mouthwashes/gels (Flocare gel (0.4% stannous fluoride), Pascal gel (topical APF fluoride), Pro-Relief mouthwash (sodium fluoride), and Plax Soin mouthwash (sodium fluoride)), and distilled water as a control, were selected. These were divided into five groups: Group 1: Flocare gel; Group 2: Pascal gel; Group 3: Pro-Relief mouthwash; Group 4: Plax Soin mouthwash; and Group 5: distilled water (control). Prepared restorative materials samples were immersed in the groups of mouthwashes/gels and the distilled water (control) for 24, 48, and 72 h. The discoloration that all materials exhibited with all immersion groups was significantly different at each of the three time periods for all groups (p < 0.05). Results from immersion in Flocare gel, Pascal gel, Pro-Relief mouthwash, and Plax Soin mouthwash were statistically significant (p < 0.05). The color change chroma was not significant for Pro-Relief and Plax Soin mouthwash (p > 0.05). Mouthwashes/gels affect color shifting for all composite resin materials, and changes are exaggerated over time. However, discoloration effects are not perceptible to the human eye.

Chitosan Biomaterials for Current and Potential Dental Applications

Chitosan (CHS) is a very versatile natural biomaterial that has been explored for a range of bio-dental applications. CHS has numerous favourable properties such as biocompatibility, hydrophilicity, biodegradability, and a broad antibacterial spectrum (covering gram-negative and gram-positive bacteria as well as fungi). In addition, the molecular structure boasts reactive functional groups that provide numerous reaction sites and opportunities for forging electrochemical relationships at the cellular and molecular levels. The unique properties of CHS have attracted materials scientists around the globe to explore it for bio-dental applications. This review aims to highlight and discuss the hype around the development of novel chitosan biomaterials. Utilizing chitosan as a critical additive for the modification and improvement of existing dental materials has also been discussed.

The Impact of Hyposalivation on Quality of Life (QoL) and Oral Health in the Aging Population of Al Madinah Al Munawarrah

Hyposalivation (HS) affects aging individuals by causing pain and discomfort in the oral cavity. The aim here was to determine the impact of hyposalivation and the saliva pH on the quality of life and caries status of geriatrics population. A total of 138 male outpatients attending the Taibah University College of Dentistry (TUCoD) dental clinic were included in the study. The saliva flow, pH, Quality of Life (QoL), and caries status were recorded. The QoL was measured using the Arabic version of the Oral Health Impact Profile-14 (OHIP-14), and the caries status was recorded using the Decayed, Missed, Filled Teeth (DMFT) index. The mean age was 67.5 years and 64% were classified as having hyposalivation. The older respondents tended to have a lower saliva flow and pH compared to their younger counterparts. There was a significant inverse association (p = 0.02) between the caries status and mean saliva flow rate. There was also a significant (p < 0.001) positive correlation between caries and the OHIP-14 scores (Spearman’s ρ = 0.293). The prevalence of hyposalivation was relatively high and there was an inverse relationship between the age, the saliva flow, and pH. Those with more caries reported significantly poor QoL.