Effect of Gum Arabic powder on the mechanical properties of denture base acrylic.

Objective: This study aimed to improve the mechanical properties of denture base material using various concentrations of natural biopolymer, i.e., Gum Arabic (GA). Methods: This experimental study was conducted at the Dental Health Department of the College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia from May 2022 to July 2022. After obtaining exemption from the institutional review board, the powdered GA was added in ratios of weight 5, 10, and 20% to PMMA heat-cured acrylic powder to produce bar-shaped samples (65 × 10 × 30 mm3 in dimensions). While the control group was prepared as such. Micro hardness (n=10/group) and fracture toughness (n=10/group) were evaluated. One-way analysis of variance method was used to statistically analyze the results (p<0.05) using SPSS version 23. Results: Significant differences were observed for micro hardness (p<0.001) and fracture toughness (p=0.007) between the means of the different study groups. The control group exhibited the highest micro hardness (22.5±0.6 VHN) and fracture toughness (1.25±0.11 MPa.m1/2) value among the study groups. While 20 wt. % GA and 10 wt. % GA groups showed the lowest micro hardness and fracture toughness values, respectively. Conclusions: GA powder might not be an appropriate reinforcing material for denture base or the higher filler loading of GA in denture base acrylic might be detrimental to the mechanical properties.

Surface, mechanical and chemical properties of modified denture resin using natural biopolymer.

Objective: This laboratory study determined the surface, mechanical and chemical properties of polymethyl methacrylate (PMMA) denture resin reinforced with micron-sized Gum Arabic (GA) powder in different weight ratios. Methods: This laboratory study was conducted at the Dental Health Department of the College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia from November 2022 to February 2023. Three experimental denture resins were prepared by incorporating GA powder in heat-polymerized PMMA powder using different wt.% (5, 10, and 20 wt.%). While pristine PMMA served as the control group. A total of ten bar-shaped specimens with dimensions of 65 mm × 10 mm × 3.5 mm were prepared for each study group. The surface properties (micro CT and SEM evaluation), mechanical properties (Nanohardness, elastic modulus and flexural strength) and chemical properties (FTIR) were conducted. The data were statistically analyzed using the one-way analysis of variance and Tukey's post hoc tests (p<0.05). Results: The surface and bulk properties of experimental GA-reinforced PMMA resin materials deteriorated while the mechanical properties were also negatively altered using GA-based PMMA denture resin. A linear correlation was observed between weak mechanical properties and increasing wt.% of GA in denture resin. Conclusions: The incorporation of GA powder in denture resin might not be a viable option. The surface and mechanical properties of experimental PMMA composites were adversely affected compared to the control group.

Chloro-aluminum phthalocyanine-mediated photodynamic therapy in the treatment of stage-II chronic periodontitis among smokers.

PURPOSE: To assess the clinical periodontal, bacterial, and immunological outcomes of chloro-aluminum phthalocyanine-mediated photodynamic therapy (PDT) as an adjunct to dental scaling (DS) versus DS alone among cigarette smokers (CS) and never-smokers (NS). METHODS: A total of 26 patients (13 CS and 13 NS) with clinical and radiographic diagnosis of stage-II chronic periodontitis were recruited. Each patient from both groups were subjected with two parallel therapies (split-mouth): PDT + DS (test side) and DS alone (control side). Periodontal parameters were investigated by evaluating plaque scores (PS), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), and alveolar bone loss (ABL). Subgingival plaque was collected to detect and quantify Porphyromonas gingivalis and Tannerella forsythia using real-time quantitative polymerase chain reaction (RT-qPCR) assay. Gingival crevicular fluid was sampled for the quantification of interleukin (IL)-1ß and tumor necrosis factor-alpha (TNF-α) using enzyme linked immunosorbent assay. All assessments were performed at baseline, 3 months, and 6 months. RESULTS: Bleeding on probing was significantly reduced at 6 months after PDT + DS in CS groups (p < .05). Mean PD and CAL significantly reduced after both PDT + DS and DS subgroups and among NS and CS groups (p < .05). At 6 months follow-up, the copy number of both P. gingivalis and T. forsythia remained significantly high in CS group (p < .01). Only PDT + DS subgroup in CS significantly reduced the counts of P. gingivalis and T. forsythia at 3 months and 6 months (p < .05). Only at 6 months did PDT + DS showed statistically significantly reduced IL-1ß levels in the NS group (p < .01). TNF-α levels significantly reduced in CS group with PDT + DS and DS alone at both 3 months and 6 months follow-up (p < .01). CONCLUSION: Chloro-aluminum phthalocyanine-mediated PDT helped to improve the non-surgical periodontal therapy outcomes among stage-II chronic periodontitis patients among smokers and never-smokers.

Antimicrobial photodynamic therapy using chloro-aluminum phthalocyanine for treating advanced stage-III periodontitis in smoking patients.

PURPOSE: To evaluate the bacterial, clinical, and cytokine profile of adjunctive photodynamic therapy using chloro-aluminum phthalocyanine (CAP/aPDT) with root surface debridement (RSD) versus RSD alone in cigarette smokers (CS) and never-smokers (NS) during the period of 6 months. METHODS: Twenty-nine patients [CS - 14 and NS - 15] were recruited for the trial having stage-III periodontitis. All candidates from the study groups were subjected to a split-mouth treatment technique receiving CAP/aPDT + RSD and RSD alone. Periodontal parameters including plaque levels (PL), bleeding on probing (BP), probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. Polymerase chain reaction (qPCR) assay was used to analyze the copy numbers of Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf). Levels of tumor necrosis factor-alpha (TNF-α) interleukin (IL)-6 in the crevicular fluid were evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: CAP/aPDT+RSD decreased BP in smokers after 6 months (p < .05). Probing depth and CAL reported statistically significant reductions within both CAP/aPDT+RSD and RSD groups and also within the NS and CS (p < .05). Pg and Tf stayed elevated in smokers at the 6-month evaluation period (p < .01). Only CAP/aPDT+RSD significantly decreased Pg and Tf at 3- and 6-month follow-up in smokers (p < .05). CAP/aPDT+RSD showed decreased IL-6 levels in the NS during the 6-month follow-up (p < .01). TNF-α levels were significantly reduced in the CS group with CAP/aPDT+RSD and RSD alone until 6 months (p < .01). CONCLUSION: CAP-mediated aPDT along with nonsurgical periodontal therapy helped to improve the bacteriological outcomes among smokers and never-smokers with stage-III CP patients.

Mechanical Properties of the Modified Denture Base Materials and Polymerization Methods: A Systematic Review.

Amidst growing technological advancements, newer denture base materials and polymerization methods have been introduced. During fabrication, certain mechanical properties are vital for the clinical longevity of the denture base. This systematic review aimed to explore the effect of newer denture base materials and/or polymerization methods on the mechanical properties of the denture base. An electronic database search of English peer-reviewed published papers was conducted using related keywords from 1 January 2011, up until 31 December 2021. This systematic review was based on guidelines proposed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search identified 579 papers. However, the inclusion criteria recognized 22 papers for eligibility. The risk of bias was moderate in all studies except in two where it was observed as low. Heat cure polymethyl methacrylate (PMMA) and compression moulding using a water bath is still a widely used base material and polymerization technique, respectively. However, chemically modified PMMA using monomers, oligomers, copolymers and cross-linking agents may have a promising result. Although chemically modified PMMA resin might enhance the mechanical properties of denture base material, no clear inferences can be drawn about the superiority of any polymerization method other than the conventional compression moulding technique.

A review of membrane development in membrane distillation for emulsified industrial or shale gas wastewater treatments with feed containing hybrid impurities.

Investigations on membrane materials for membrane distillation (MD) and its applications have been ongoing since the 1990s. However, a lack of materials that produce robustly stable and up-to-the-mark membranes for MD for different industrial applications remains an ongoing problem. This paper provides an overview of materials developed for MD applications. Although key aspects of published articles reviewed in this paper pertain to MD membranes synthesized for desalination, future MD can also be applied to organic wastewater containing surfactants with inorganic compounds, either with the help of hybrid treatment processes or with customized membrane materials. Many industrial discharges produce effluents at a very high temperature, which is an available driving force for MD. However, there remains a lack of cost-effective membrane materials. Amphiphobic and omniphobic membranes have recently been developed for treating emulsified and shale gas produced water, but the problem of organic fouling and pore wetting remains a major challenge, especially when NaCl and other inorganic impurities are present, which further deteriorate separation performance. Therefore, further advancements in materials are required for the treatment of emulsified industrial wastewater containing surfactants, salts, and for oil or shale gas wastewater for its commercialized reuse. Integrated MD systems, however, may represent a major change in shale gas wastewater and emulsified wastewater that are difficult to treat.

Novel approach in managing post-extraction alveolar bone dimensions.

This case report presents a novel approach towards the preservation of alveolar ridge dimensions following the extraction of an upper left lateral incisor. The extracted teeth of a 56-year old patient was ground with a diamond bur running under the normal saline spray. Sedimented fine tooth-powder was collected and mixed with 2.0 ml of patient's intravenous blood. The powdered paste pushed inside the tooth socket by means of plugger until the socket was filled, leaving a space of 3mm only. The socket was sutured with a non-resorbable silk material. After one week, the adjacent tooth were endodontically prepared and a fixed partial denture was placed on the prepared abutments. The results suggest therapeutic approach with no immune response, which can be implemented at chairside. A significant preservation of alveolar ridge can be maintained using this novel approach.

Sociodemographic Characteristics as Predictors of Satisfaction in Public and Private Dental Clinics.

OBJECTIVE: This study aimed to investigate influence of multiple sociodemographic characteristics on the patient satisfaction levels in outpatient public and private dental practices of Riyadh, Saudi Arabia. METHODS: Questionnaire-based survey data were collected from 500 patients, 250 each from the public and private dental clinics of Riyadh, Saudi Arabia from September to December, 2017. Questions related to demographic factors and service attributes were included. A Likert scale of 5-points was used to measure satisfaction levels. Data was analyzed to calculate the descriptive and inferential statistics (analysis of variance and multiple regression analysis) to find the statistical difference (p < 0.01). RESULTS: Satisfaction level differed significantly by education level (P< 0.001) and the type of clinic (P<0.001). The multiple regression analysis suggest that all variables influenced satisfaction, except age and marital status. The satisfaction score was higher by 27% for private clinics compared to public clinics. CONCLUSION: This study was exploratory and revealed an effect of individual variables on overall satisfaction score of the services attributes. Future plans for patient care could be developed with the help of this research.

In vitro assessment of stainless steel orthodontic brackets coated with titanium oxide mixed Ag for anti-adherent and antibacterial properties against Streptococcus mutans and Porphyromonas gingivalis.

Orthodontic brackets made from stainless steel were introduced in dentistry, though they have less ability in reducing enamel demineralization and are not successful in preventing microbial as well as biofilm growth. In this study, we evaluated the significant role of different brackets in reducing enamel demineralization indirectly. Results from different tests indicate the significant reduction in adhesion, biofilm formation and slow growth of tested bacterial species on brackets coated with Ag + TiO2 and found to be statistically significant lower than control. There was no loss in cell viability in all brackets indicating that the cells are biocompatible with different bracket materials. Scanning electron microscopy showed less bacteria attached with the surface coated with Ag + TiO2 indicated that bacteria were losing adherent nature on coated surface. In conclusion, TiO2+Ag coating on stainless steel brackets possessed anti-adherent properties and also have demonstrable antibacterial properties therefore helps in preventing dental caries and plaque accumulation indirectly. The cell compatibility of TiO2+Ag coated brackets is superior to the uncoated samples therefore can be used in orthodontics as it not only provide suitable antimicrobial activity and resistance to biofilm formation but also sustained the cell viability of human gingival fibroblast (HGF) cell lines.

Recent Trends in Surface Treatment Methods for Bonding Composite Cement to Zirconia: A Reveiw.

PURPOSE: To evaluate the in vitro studies conducted in the last six years on new zirconia materials to discover and explore current trends in bonding composite cement to zirconia substrate. MATERIALS AND METHODS: An in-depth review of the in vitro studies performed between 2010 and 2016 was conducted, focusing on the current trends in surface conditioning methods for zirconia ceramic. PubMed was used for searching the literature. Resin composite bonding to zirconia, zirconia surface coating, and zirconia surface treatment method were the keywords used. Complete scientific articles were reviewed and evaluated for appropriateness. RESULTS: The literature survey showed a variety of surface treatment techniques comprising grit blasting (laboratory or chairside) with or without silica-coated alumina particles, the use of materials containing phosphate monomers, different silanes and primers, laser irradiation, Si vapor-phase deposition, and selective infiltration etching. CONCLUSIONS: The problem of composite cement bonding to zirconia has yet to be definitively solved. Nevertheless, the application of phosphate monomer on tribochemically silica-coated zirconia surfaces is currently the least complicated and most efficaceous means of bonding composite cement to zirconia. Selective infiltration etching seems to be a promising technique for establishing a durable bond between composite cement and zirconia, and should be studied further.

Impact of network aided platforms as educational tools on academic performance and attitude of pharmacology students.

OBJECTIVE: This cross-sectional study aimed to examine the impact of learning management system and WhatsApp application as educational tools on students' academic achievement and attitude. METHODS: The sample population was the students of six medical colleges of Riyadh, Saudi Arabia attending Medical Pharmacology's semester course in Bachelor of Medicine, Bachelor of Surgery (MBBS) program from September 2016 to January 2017. An exploratory approach was adopted based on a comparison between students exposed to only in-class lectures (Group-N), in-class lectures together with WhatsApp platform to disseminate the lecture slides (Group-W) and students group with in-class lectures facility blended with Learning Management System (LMS) and WhatsApp platform (Group-WL). The students' grades were assessed using unified multiple choice questions at the end of the semester. Data were analyzed using descriptive statistics and Pearson correlation (p<0.01). RESULTS: Using learning management system (LMS) and/or WhatsApp messenger tool showed a significant positive correlation in improving students' grades. Additionally, use of WhatsApp enhances students' in-class attendance though statistically insignificant. CONCLUSION: The results are pivotal for a paradigm shift of in-class lectures and discussion to mobile learning (M-learning). M-learning through WhatsApp may be as an alternative, innovative, and collaborative tool in achieving the required goals in medical education.

Spectrophotometric assessment of different surface coating materials on conventional glass ionomer cement.

The purpose of this in vitro study was to analyse the absorbance of dye material in conventional glass ionomer cement (GIC) by applying various commercially available surface protecting layers on GIC. 90 disc-shaped specimens were made using brass mold measuring 7mm in diameter and 2mm in thickness. 30 specimens were selected for each week testing having 6 groups (n=5). The groups were: G1 (Control group), G2 (Nail polish coated GIC), G3 (Master bond coated GIC), G4 (Copal varnish coated GIC), G5 (Varnal coated GIC), G6 (Cold mold seal coated GIC). The specimens of each group were immersed in a separate test tube filled with methylene blue dye, and placed in an incubator (37°C±2°C) for 1 week, 2 weeks and 3 weeks' time. After required time period, the specimens were rinsed under distal water for 1 minute and air dried for 1 hour. Next, the specimens of each group were put into new test tubes containing 1ml absolute alcohol and again stored at (37°C±2°C) for 24 hours. Absorbance were recorded in ultravoilet spectrophotometer. Results were analysed by Student t-test and Pearson's correlation. The results suggest that varnal and copal varnish are effective protecting materials with significant difference (P<0.01) after 3 weeks time. Our results conclude that the application of suitable protecting material may lead to longevity of GIC restorative biomaterial in a complexed oral environment.

Influence of mouth rinses on the surface hardness of dental resin nano-composite.

OBJECTIVE: The aim of this research was to assess the effect of mouth rinses with and without alcohol on the hardness of dental nano-filled composite. METHODS: The micro-hardness of fifty circular disk shaped specimens of 7 mm x 2 mm were measured after 14 days. Specimens were immersed into alcohol containing (Listerine and Colgate Perioguard) and alcohol-free (Prodent and Sensodyne Oral antiseptic) mouth rinse solutions. Artificial saliva served as the control. Vickers Micro-hardness was measured with a 30gram load for 30 seconds dwell time by using a diamond indenter. Significant differences were represented by p<0.05, whereas highly significant difference represented by p<0.01. The level of significance (p) was calculated with the help of repeated measure ANOVA. For multiple comparisons, Tukey's multiple comparison test was used. RESULTS: Statistical analysis revealed highly significant difference between specimens immersed in artificial saliva (control) and Listerine (p<0.01). Whereas significant difference were observed between control and Colgate Periogard (p<0.05). However, no significant difference was observed on comparing Prodent and Sensodyne Oral antiseptic mouth rinses with control group(p>0.05). Control specimens depicted highest value of micro-hardness(60.5746 ± 3.2703) compared to the lowest value seen in specimens immersed in Listerine solvent(54.4687 ± 1.0937). CONCLUSION: Alcohol containing mouth rinsing solutions have more deleterious effect on hardness of nano composites as compared to alcohol-free mouth rinses.

Effect of different pH solvents on micro-hardness and surface topography of dental nano-composite: An in vitro analysis.

OBJECTIVE: Erosion of tooth surface is attributed to recent shift in diet pattern and frequent use of beverages. The aim of this research was to evaluate the effects of different beverages on surface topography and hardness of nano-filled composite material. METHODS: Sixty flat disc shaped resin composite samples were fabricated and placed in distilled water for 24 hours. After 24 hours test samples were dried and divided into 4 groups. Group A (n=15) specimens were placed in tight amber bottle comprising 25 ml of artificial saliva. Similarly Group B, C and D were stored in equal amounts of orange juice, milk and coca cola drink respectively. Samples were checked for hardness and surface changes were evaluated with scanning electron microscopy. RESULTS: There were strong significant difference observed in samples immersed in orange juice and artificial saliva. A strong significant difference was seen between Group D and Group A. Group A and Group C showed no significant difference. The micro-hardness test showed reduced values among all samples. CONCLUSION: Beverages consumed daily have a negative influence on hardness and surface degradation of nano-filled dental composite. Comparatively, nano-filled composites possess higher surface area to volume ratio of their fillers particle size may lead to higher surface roughness than other resin based dental biomaterials.

Utilizing an Oxidized Biopolymer to Enhance the Bonding of Glass Ionomer Luting Cement Particles for Improved Physical and Mechanical Properties.

This study aimed to determine the reinforcing effect of two weight ratios of Gum Arabic (GA) natural biopolymer, i.e., 0.5% and 1.0% in the powdered composition of glass ionomer luting cement. GA powder was oxidized and GA-reinforced GIC in 0.5 and 1.0 wt.% formulations were prepared in rectangular bars using two commercially available GIC luting materials (Medicem and Ketac Cem Radiopaque). The control groups of both materials were prepared as such. The effect of reinforcement was evaluated in terms of microhardness, flexural strength (FS), fracture toughness (FT), and tensile strength (TS). The internal porosity and water contact angle formation on the study samples were also evaluated. Film thickness was measured to gauge the effect of micron-sized GA powder in GA-GIC composite. Paired sample t-tests were conducted to analyze data for statistical significance (p < 0.05). The experimental groups of both materials containing 0.5 wt.% GA-GIC significantly improved FS, FT, and TS compared to their respective control groups. However, the microhardness significantly decreased in experimental groups of both cements compared to their respective control groups. The addition of GA powder did not cause a significant increase in film thickness and the water contact angle of both 0.5 and 1.0 wt.% GA-GIC formulations were less than 90o. Interestingly, the internal porosity of 0.5 wt.% GA-GIC formulations in both materials were observed less compared to their respective control groups. The significantly higher mechanical properties and low porosity in 0.5 wt.% GA-GIC formulations compared to their respective control group indicate that reinforcing GA powder with 0.5 wt.% in GIC might be promising in enhancing the mechanical properties of GIC luting materials.

Effectiveness of photodynamic therapy adjunct to oral debridement in improving clinical, microbiological, and pain in necrotizing ulcerative gingivitis.

To evaluate the efficacy of photodynamic therapy (PDT) as adjunctive to oral debridement (OD) in the improvement of clinical, microbiological, and pain in patients with necrotizing ulcerative gingivitis (NUG). Patients with NUG were split into two groups: Group-OD + PDT received PDT with OD, while Group-OD underwent OD alone. Clinical inflammatory parameters including full mouth plaque scores (FMPS), full mouth bleeding scores (FMBS), and probing depth (PD) were assessed. Fusobacterium nucleatum and Prevotella intermedia were analyzed using the polymerase chain reaction technique. Pain examination was done using various pain scales. Group PDT + OD showed more reduction in FMPS, FMBS, and greater reduction in F. nucleatum and P. intermedia count compared to group OD at 12 weeks follow up (p < 0.01). Group PDT + OD showed significantly lower pain scores at 12 weeks (p < 0.05). PDT was more effective in improving clinical parameters, and reducing bacterial counts and pain in NUG patients than dental scaling alone.

Effectiveness of photodynamic therapy on clinical and biomarker related periodontal parameters and oral health related quality of life (OHRQoL) in Parkinson's disease patients with stage III periodontitis.

AIMS: To evaluate the clinical, radiographic, immune modulatory biomarkers and quality of life with the application of photodynamic therapy (PDT) as an adjunctive treatment to dental scaling and root planing (SRP) in patients with chronic periodontitis and Parkinson's disease. METHODOLOGY: Individuals who had a confirmed diagnosis of stage III periodontitis and stage 4 Parkinson's disease according to Hoehn and Yahr scale were involved in this study. The participants were divided into two groups: Group SRP (n = 25) received traditional dental scaling procedure including full-mouth debridement and disinfection, and Group PDT + SRP (n = 25) received both traditional cleaning procedures along with adjunctive chloro­aluminum phthalocyanine (CAPC) gel (0.005% concentration) mediated PDT. CAPC photosensitizer was activated using a diode laser (wavelength=640 nm, energy=4 J, 150 mW power, and overall power density of 300 J/cm2) for 60 s. The study measured clinical parameters such as plaque score (PI), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), and radiographic alveolar bone loss (ABL). Proinflammatory cytokine levels such as interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) and oral health related quality of life were also assessed. RESULTS: The mean age of patients in Group SRP was 73.3 years, while the mean age in Group PDT + SRP was 71.6 years. The PDT + SRP group showed a significant reduction in all clinical parameters at 6 and 12 months compared to the SRP group alone (p < 0.05). IL-6 and TNF-α levels were significantly reduced in the PDT + SRP group at 6 months compared to the SRP group alone (p < 0.05). However, at 12 months, both groups showed comparable TNF-α levels. The results showed that Group PDT + SRP had significantly lower OHIP scores compared to Group SRP, with a mean difference of 4.55 (95% confidence interval [CI]: 1.98 to 7.12) (p < 0.01). CONCLUSION: Combined SRP with PDT showed significant improvement compared to SRP alone in terms of clinical parameters, cytokine levels, and oral health-related quality of life in individuals diagnosed with stage III periodontitis associated with Parkinson's disease.

Fiber-reinforced composites in dentistry - An insight into adhesion aspects of the material and the restored tooth construct.

OBJECTIVE: This review aimed to highlight the insight into adhesion aspects within the components of the glass FRC (i.e., fiber and matrix) and between resin luting material and the glass FRC construction. METHODS: The fundamentals of semi-interpenetrating polymer network (semi-IPN) based FRCs and their advantages in forming a solid adhesive interface with indirect FRC restoration, dental adhesive, and luting cement are elaborated. The important resin matrix systems and glass fibers used in FRCs are discussed. This is principally based on a survey of the literature over Medline/PubMed, Web of Science, and Scopus databases and a review of the relevant studies and publications in scientific papers in international peer-reviewed journals for the specific topic of biomaterials science. The keywords used for the search approach were: adhesion, fiber-reinforced composite, glass fiber, and semi-interpenetrating polymer network. RESULTS: The polymer matrix systems of semi-IPN-based FRCs and formation of secondary-IPN layer are pivotal for bonding of multiphasic indirect dental constructs and repair. Additionally, describing areas of indication for FRCs in dentistry, explaining the adhesion aspects of FRC for the cohesion of the material itself, and for obtaining durable adhesion when the FRC construct is luted to tooth and remaining dentition. Current progress in the field of FRC research and future directions are summarized and presented. SIGNIFICANCE: By understanding the isotropic-anisotropic nature of fibers and the interfacial adhesion within the components of the FRC; between resin cement and the FRC construction, the clinically successful FRC-based multiphasic indirect tooth construct can be achieved. The interfacial adhesion within the components of the FRC and between resin luting material and the FRC construction play a key role in adhesion-based unibody dental restorations.

Oxidized Natural Biopolymer for Enhanced Surface, Physical and Mechanical Properties of Glass Ionomer Luting Cement.

This laboratory investigation aimed to synthesize and characterize micron-sized Gum Arabic (GA) powder and incorporate it in commercially available GIC luting formulation for enhanced physical and mechanical properties of GIC composite. Oxidation of GA was performed and GA-reinforced GIC in 0.5, 1.0, 2.0, 4.0 & 8.0 wt.% formulations were prepared in disc-shaped using two commercially available GIC luting materials (Medicem and Ketac Cem Radiopaque). While the control groups of both materials were prepared as such. The effect of reinforcement was evaluated in terms of nano hardness, elastic modulus, diametral tensile strength (DTS), compressive strength (CS), water solubility and sorption. Two-way ANOVA and post hoc tests were used to analyze data for statistical significance (p < 0.05). FTIR spectrum confirmed the formation of acid groups in the backbone of polysaccharide chain of GA while XRD peaks confirmed that crystallinity of oxidized GA. The experimental group with 0.5 wt.% GA in GIC enhanced the nano hardness while 0.5 wt.% and 1.0 wt.% GA in GIC increased the elastic modulus compared to the control. The CS of 0.5 wt.% GA in GIC and DTS of 0.5 wt.% and 1.0 wt.% GA in GIC demonstrated elevation. In contrast, the water solubility and sorption of all the experimental groups increased compared to the control groups. The incorporation of lower weight ratios of oxidized GA powder in GIC formulation helps in enhancing the mechanical properties with a slight increase in water solubility and sorption parameters. The addition of micron-sized oxidized GA in GIC formulation is promising and needs further research for improved performance of GIC luting composition.

Using Functionalized Micron-Sized Glass Fibres for the Synergistic Effect of Glass Ionomer on Luting Material.

This laboratory experiment was conducted with the objective of augmenting the mechanical properties of glass ionomer cement (GIC) via altering the composition of GIC luting powder through the introduction of micron-sized silanized glass fibres (GFs). Experimental GICs were prepared through the addition of two concentrations of GFs (0.5% and 1.0% by weight) to the powder of commercially available GIC luting materials. The effect of GF in set GIC was internally evaluated using micro-CT while the mechanical attributes such as nano hardness (nH), elastic modulus (EM), compressive strength (CS), and diametral tensile strength (DTS) were gauged. Additionally, the physical properties such as water solubility and sorption, contact angle (CA), and film thickness were evaluated. Reinforced Ketac Cem Radiopaque (KCR) GIC with 0.5 wt.% GF achieved improved nH, EM, CS, and DTS without affecting the film thickness, CA or internal porosity of the set GIC cement. In contrast, both GF-GIC formulations of Medicem (MC) GIC showed the detrimental effect of the GF incorporation. Reinforcing KCR GIC with 0.5 wt.% silanized GFs could improve the physical and mechanical attributes of luting material. Silanized GF, with optimal concentration within the GIC powder, can be used as a functional additive in KCR GIC with promising results.