American Dental Association Specification Research Articles

Impact of colloidal silver nanoparticles (AgNPs) added for their antimicrobial efficacy on the compressive strength of poly(methyl methacrylate)-based acrylic denture base resin subjected to two different curing cycles: An in vitro study

Abstract Introduction: Colloidal silver nanoparticles (AgNPs) have been incorporated into acrylic resins to induce antimicrobial properties. However, as additives, they can influence the mechanical properties of the final product. The aim of the present study was to evaluate compressive strength of acrylic denture base resin incorporated with different concentrations of AgNPs subjected to two different curing cycles. Materials and Methods: Lucitone 199 acrylic denture base resin was used in the present in vitro study design because of its high-impact strength, while AgNPs were incorporated at 0.5% and 5% concentration by polymer mass. Specimens devoid of AgNPs were used as controls. The specimens were fabricated according to the American Dental Association specification No. 12 for denture base resin: Second revision, BS specification 2482 and tested for compressive strength using universal testing machine. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 19 (SPSS Inc., Chicago, IL, USA). Descriptive statistics was used to compare two different curing cycles; while one-way analysis of variance and Kruskal–Wallis H-test were used for statistical analysis. P <0.05 was considered statistically significant. Results: Colloidal silver nanoparticles (AgNPs) incorporation at 0.5% concentration increased the mean compressive strength in both the short and long curing cycles by 5.3% and 8.3% respectively when compared with the control group. Conclusions: The findings of the present study suggested that the mean compressive strength of acrylic denture base resin modified with 0.5% concentration of AgNPs was above the control group, both in the short and long curing cycles. However, at 5% concentration of AgNPs, decrease in compressive strength compared to the control group was observed, both in short and long curing cycles, giving it a questionable prognosis, while the results were found to be statistically significant. The following core competencies are addressed in this article: Practice-based learning and improvement, Patient care and procedural skills, Systems-based practice, Medical knowledge.

Preparation and characterization of novel nano-tricalcium silicate-58s bioactive glass-based root canal sealer

Introduction: Calcium silicate-based root canal sealers are gain significant interest in the recent endodontic treatment, but the high solubility and long setting time are the most shortcoming. Therefore, this study aimed to develop new nano-tricalcium silicate-58s bioactive glass (BG)-based root canal sealer with phosphate-buffered saline (PBS) as a liquid precursor, as well as to evaluate the hydration reaction of the newly prepared sealer. Materials and Methods: Different formulae were prepared by adding nano-zirconium dioxide (ZrO2) and 58s BG to the tricalcium silicate (C3S) at different concentrations. Furthermore, two types of liquid were used as precursors (PBS and distilled water). Then after, the setting time and solubility were evaluated for each prepared formula. Statistical analysis was performed using analysis of variance and Tukey tests. The formula that had the best properties was characterized by X-ray diffraction and Fourier transform infrared spectroscopy. Results: It was found that the ZrO2 at 25%, BG at 30%, and the use of PBS as a liquid improved the physical properties of the prepared sealer. Results indicated that the main hydration reactions by products for the best formula were noncrystalline calcium silicate hydrate, crystalline Ca(OH)2, CaCO3, Ca(H2PO4)2, Ca3(PO4)2, and hydroxyapatite. Conclusions: The experimental formula that composed mainly of 45% C3S, 25% ZrO2, and 30% BG as a powder and PBS as a liquid precursor had superior properties, which is in line with the American Dental Association specification.

Comparative Assessment of Flexural Strength in Heat-cured Polymethyl Methacrylate Resin Reinforced with Silver Nanoparticles, Siwak, and Fluconazole: An In-vitro Study

Introduction: For crafting complete dentures, Polymethylmethacrylate (PMMA) has long been the material of choice. Various reinforcements are being used to enhance the properties of PMMA and minimise denture fracture. Aim: The present in-vitro study compared the flexural strength of PMMA resin samples reinforced with Silver Nanoparticles (Ag NP), siwak, and fluconazole. Materials and Methods: The present in-vitro experiment was conducted from July to August 2017 at the Prosthodontics Department of a Dental College with technical support from the Centre for Scientific Research and Development (CSRD), affiliated with People’s University in Bhopal, Madhya Pradesh, India. Flexural testing was conducted at the Central Institute of Plastic Engineering and Technology (CIPET), Bhopal. A total of 120 acrylic resin samples, each measuring 65 mm in length, 10 mm in width, and 2.5 mm in thickness, were fabricated in accordance with American Dental Association (ADA) Specification No. 12. These specimens were categorised into four distinct groups. The first group consisted of only PMMA resin (Group A), while the remaining three groups comprised PMMA resin enhanced with AgNP (Group B), Siwak (Group C), and Fluconazole (Group D), respectively, with each group containing 30 samples. Subsequently, these specimens underwent a flexural strength assessment through a 3-point flexural test. The statistical analysis to assess and compare the mean flexural strength of the samples was conducted. The present analysis was performed first by applying an Analysis of Variance (ANOVA) test, followed by pairwise comparisons with Tukey’s Post-hoc test. A p-value less than 0.05 was used to determine statistical significance. Results: The mean flexural strength (±Standard Deviation) in N/mm2 for PMMA; PMMA+AgNP; PMMA+Siwak and PMMA+ Fluconazole was 82.33±5.18; 80.55±5.67; 71.50±10.15; and 74.03±10.84, respectively. The mean flexural strengths of the PMMA and PMMA+AgNP groups were similar (p=0.842). However, the flexural strength of the Siwak+PMMA and Fluconazole+PMMA groups was significantly less than that of the other two groups. Conclusion: The flexural strength of PMMA is unaffected by the inclusion of AgNP at a concentration of 1%, and its incorporation would allow the benefit from its antibacterial qualities. It is not advised to add fluconazole or siwak because doing so reduces the flexural strength.

Influence of Three Different Denture Cleansers on Surface Roughness and Strength of Heat-polymerizing Resin: An In Vitro Study.

The purpose of the current study was to evaluate the impact of three different denture cleansers on the strength and surface roughness of heat-polymerizing resin. A total of 120 resin discs (10 mm in diameter and 2 mm thick) were created using a stainless steel mold for surface roughness testing and flexural strength testing (in accordance with the American Dental Association (ADA) Specification No.12). Samples were divided into one of three groups (40 samples in each group): group I: Clanden, group II: Clinsodent, group III: Fittydent. Samples were immersed in denture-cleansing solutions for 30 minutes every day, and this process was repeated over a period of 15 days. Samples were stored in distilled water at room temperature in between the immersions. A surface analyzer was utilized to compare the surface roughness of each sample before and after immersion treatments. For recording flexural strength, each sample was subjected to three-point bending test by mounting samples on Universal testing machine. Comparing mean values between groups using one-way ANOVA and the Tukeys honest significant difference (HSD) post hoc test. A significance level of 0.05 was used for all statistical calculations Results: After 15 days, the maximum change of mean surface roughness of heat-polymerizing resin was found in Clanden denture cleanser group (2.64 ± 0.12) followed by Clinsodent group (2.26 ± 0.09) and Fittydent group (1.92 ± 0.06). After 15 days, the maximum change of mean flexural strength changes of heat-polymerizing resin was found in Clanden denture cleanser group (94.78 ± 0.14), followed by Fittydent group (98.64 ± 0.03) and Clinsodent group (99.26 ± 0.21). Within the limitation, the current study concluded that changes were observed in surface roughness and flexural strength of all heat-polymerizing resin samples after immersion in all three denture cleansers; but least surface roughness and flexural strength changes were observed with the Fittydent cleanser group and Clinsodent group, respectively. Cleaning dentures is crucial for maintaining both the prosthesis and oral health; therefore, it is necessary to select a cleanser that is effective without negatively affecting the base resin's qualities over time.

Effect of Gingival Hemostatic Agents on the Surface Detail Reproduction and Dimension Stability of Three Elastomeric Impression Materials.

This study aimed to evaluate the effects of aluminum chloride based hemostatic agents on the surface detail reproduction and dimension stability. Three impression materials were investigated after contaminated with three commercial astringents with different concentration of aluminum chloride. The specimens from three impression materials were fabricated with a stainless-steel mold that followed the American Dental Association specification no.19. The mold was preliminarily contaminated with three hemostatic agents racestyptine, Dryz, and Expasyl™-and 80 specimens from each impression material-polyvinylsiloxane (PVS), polyether, and polyvinylsiloxane ether (PVSE), were fabricated and subjected to each astringent. The surface detail reproduction was examined using a stereomicroscope at 4x magnification, and the dimensional stability was analyzed at 24 hr with a measuring microscope. The surface detail data were statistically analyzed with Fisher's test at a significance level of 0.05. The dimensional stability data were analyzed using two-way ANOVA and Tukey's test at a significance level of 0.05. Aluminum chloride hemostatic agents can affect the surface detail reproduction of impression materials differently (p < 0.05). Thus, the first null hypothesis was rejected. PVS showed the highest percentage of satisfactory surface detail regardless of the hemostatic agent used in this study. PVSE showed a reduced percentage of satisfactory surface detail when the concentration of aluminum chloride was high. The three hemostatic agents affected the dimensional stability of each material differently (p < 0.05). Therefore, the second null hypothesis was also rejected.

Comparative evaluation of dimensional stability, accuracy, and reproducibility of two commercially available interocclusal recording materials: An in vitro study

Abstract Aim: The study aimed to evaluate and compare the dimensional stability, accuracy, and reproducibility of two commercially available interocclusal recording materials. Settings and Design: This study was an in vitro study. Materials and Methods: Two commercially available interocclusal recording materials were taken—polyvinyl siloxane and bis-acrylic. Two groups each of 40 specimens were made, and a stainless-steel master die was prepared according to American dental association specification no. 19. The die consisted of cylindrical ruled block with a diameter of 38 mm, height of 31 mm, mold, and a metal riser. Materials were homogenously mixed and loaded in the prepared die to obtain the specimen in the form of a disc measuring 3 mm in thickness and 30 mm in diameter with three parallel lines on the surface designated as X, Y, and Z, and two vertical lines marked as CD, C’D’. The specimens were submerged in a 36 ± 1°C water bath for 3 min. Distance between lines was measured with the contour measuring device Contracer at 1, 24, 48, and 72 h time intervals, and the values were statistically analyzed. Statistical Analysis Used: The samples were statistically analyzed using the statistical software (STATA 15.0), t test was used to access the significant differences, and the results were presented. The level of statistical significance was set at less than 0.05. Results: Both the materials showed maximum accuracy and dimensional stability in the initial stages but decreased as the time factor increased. The results showed a less significant percentage of dimensional change for bis-acrylic-based material, whereas polyvinyl siloxane exhibited significant dimensional changes up to 48 h. Conclusion: Dimensional changes were influenced by both material and time factors, and the difference exhibited by the materials were statistically significant at 1, 24, and 48 h.

Effect of Graphene Oxide Nanoparticles on the Flexural Strength of all CeramicsAn In-vitro Study

Introduction: Desirable properties of monolithic ceramics like strength, stability at high temperatures, high stiffness has made it useful for biomedical, electronic, automotive, industrial, defence and space applications. The brittle nature and mechanical unreliability of monolithic ceramics limit their use. Aim: To evaluate, if there is an increase in flexural strength of all ceramics incorporated with graphene nanoparticles. Materials and Methods: This in-vitro study was conducted in the Department of Prosthodontics and Crown and Bridge, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India, from February 2021 to April 2021, where 20 specimens of all ceramic dimensions of 20×5×3 (20 mm in length, 5 mm in width, 3 mm in thickness) according to American Dental Association (ADA) specification number 69, 1991 for flexural strength were grouped into group A (Control) with no Graphene Oxide (GO), group B with GO added. A universal testing machine with a cross head speed of 0.5 mm/ min and a span length of 15 mm was used to load the specimen in the centre. To compare the flexural strength of the two groups, the Mann Whitney U-test was used. Normality was the data assessed using Shapiro-Wilk and Kolmogorov-Smirnov test. Results: The results show that there was a significant difference (p=0.001) in the mean flexural strength between the groups. Group B had the highest mean flexural strength of 562.61 MPa, while Group A had the lowest of 458.61 MPa. Conclusion: The results concluded that, all ceramics incorporated with graphene nanoparticles showed superior flexural strength.

The Effect of Storage Time on the Dimensional Stability of Zinc Oxide Eugenol Impression Material Under Dry and Moist Conditions - An In- Vitro Study

Introduction: Accurate impression is an important factor to fabricate accurate dental casts and ultimately accurate dental prostheses. Due to time constraints, sometimes there is need of storing impression for some time which may alter the dimension. The objective of this study was to evaluate the dimensional stability of zinc oxide eugenol impression paste at different time intervals and in twoconditions, dry and wet storage. Methods: Sixty study molds of zinc oxide eugenol impression material were prepared according to American dental Association specification no 19 for non-aqueous elastic dental impression materials and the distance between two specific lines were measured at different time intervals. The paired t test was utilized to assess the difference in mean dimension of the molds from specified time to the original measurement immediately after setting. Results: In dry storage condition, the dimensional changes were not seen up to 24 hours, but at 36 hours, there is statistically significant dimensional change. In wet condition, there was significant change in dimension after 6 hours onwards. Conclusion: The dimensional change was not significant up to 24 hours in dry condition. Thus, it can be poured up to 24 hours after setting. Dimensional stability was not seen after 6 hour and hence is recommended to pour within 30 minutes if kept under wet condition.

Prevalence of oral potentially malignant disorders (OPMD) in adults of Western Maharashtra, India: A cross-sectional study.

Oral cavity cancer is estimated to be the third most common malignancy after cancer of cervix and stomach in developing countries. The objective of this study is to investigate the relationship between smoking, alcoholic consumption, betel quid chewing, and OPMD in a prospective manner. A descriptive, cross-sectional study was conducted among 35-55-year-old adults of Western Maharashtra, India. Oral cavity examination as recommended by the American Dental Association specification was followed. Data recorded were transferred from precoded survey pro forma to the computer. The prevalence of OPMD was assessed by determining the percentage of the study population affected. Analysis was done to find out the risk of oral premalignant disorders. The Chi-square (x2) test and adjusted odds ratio (ORs) with 95% confidence interval (CI) were calculated. The Statistical Package for the Social Sciences (SPSS) software version 21.0 was used for the statistical analysis and significance level was set at P < 0.05. Odds of having OPMD are five times higher for those who smoke (OR = 5.78; 95% CI, [6.18, 7.82]) as compared to those who do not. The odds of suffering from OPMD are about five times higher among those who chew as compared to those who do not (OR = 4.98; 95%CI, [2.91, 7.28]). The mean frequency of tobacco chewing per day and duration in years in participants with OPMDs was significantly higher as compared with normal oral mucosa (P < 0.05 and P < 0.05), respectively, in the use of different tobacco forms. These findings can be used to design case control or cohort studies to further understand the relation between habits and OPMD.

Novel Cold Cure Acrylic Denture Base with Recycled Zirconia Nano-Fillers That Were Functionalized by HEMA Agent Incorporation: Using the Sprinkle Approach.

BackgroundThough acrylic resins possess many useful properties, denture fracture is nevertheless a familiar issue.ObjectiveThis study aimed to determine the effect of low-percent recycled Zirconia nanoparticles as filler on the transverse strength, impact strength, surface hardness, water sorption, and solubility of resin using the sprinkle cold-curing technique.Materials and MethodsVarious formulae were prepared and mixed with PMMA (polymer) powder containing varying percentages (0.01%, 0.1%, 0.3%, and 0.5%) of recycled ZrO2NPs to mono-methyl methacrylate (MMA monomer). A 2-hydroxyethyl-methacrylate (HEMA) agent was used to functionalize recycled zirconia (ZrO2) nano-fillers. X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and dynamic light scattering were used to characterize the samples. For mechanical tests, standard metallic moulds (according to American Dental Association specification no. 27) were machined for 60 specimens’ preparation, 12 for each percent (zero, 0.01%, 0.1%, 0.3%, and 0.5%). A one-way ANOVA test was used to compare the five groups for parametric data, while the Kruskal–Wallis test was employed for nonparametric data. The P 0.05 value was accepted as the significance level. All formulae were tested for cytotoxicity at 24 and 48 hours on WI38 normal lung cell lines.ResultsThe XRD analysis demonstrated the tetragonal crystallographic structure of the recycled zirconia nanoparticles. Incorporating a low percentage of recycled ZrO2 nanoparticles (0.01%, 0.1%, 0.3%, and 0.5%) improved the tested properties of PMMA to different degrees in a significant and non-significant pattern, while the optimal tested percent was 0.3%.ConclusionThe 0.3% percentage of recycled zirconia nanoparticles maintained and improved the physical and mechanical properties of acrylic resin. Recycled ZrO2/PMMA nanocomposite is a synergistic candidate due to its economic return and clinical application safety.

Effect of Hypochlorites on the Compressive Strength and Surface Hardness of Type V Dental Stone: An In Vitro Study

The study aimed to evaluate the compressive strength and surface hardness of a type V dental stone after hypochlorite disinfection. Two types of specimens were made according to the American Dental Association (ADA) specification no. 25 for each wet compressive strength, dry compressive strength, and surface hardness. The specimens were split into three groups with 30 samples each according to the type of disinfection. All specimens were immersed in their respective disinfecting solutions for 30 minutes at room temperature and after removal, they were left to dry for 24 hours at room temperature. Total five cycles of immersion and drying were followed. A compressive strength test was done using a universal testing machine. Wet compressive strength was tested one hour after the last cycle and dry compressive strength was tested 7 days after the last cycle. Surface hardness was measured after 48 hours using Vickers hardness test. The results were statistically analyzed. There was a statistical difference between the calcium hypochlorite and sodium hypochlorite groups for both dry and wet compressive strength. The mean wet compressive strength of calcium hypochlorite was higher when compared to the sodium hypochlorite group and it was statistically significant (p = 0.042). The results were similar and statistically significant (p = 0.003) for dry compressive strength. When the mean surface hardness of the sodium hypochlorite (As) group was compared to calcium hypochlorite the results were highly significant (p = 0.0001) with the mean surface hardness of the calcium hypochlorite group more than the sodium hypochlorite group. Calcium hypochlorite used as a disinfectant showed better compressive strength and surface hardness when compared to sodium hypochlorite as a disinfectant. Dental casts poured in the contaminated impressions which might not be disinfected at all or properly. They also come in contact with the prosthesis that might be tried inside the patient's mouth and sent to a lab for corrections without disinfecting the cast causing cross-contamination between patients, dentists, and laboratory personnel. However, immersion disinfection with sodium or calcium hypochlorite might affect important properties of the cast. Any negative effect on the mechanical or physical properties of the cast will affect the final outcome of the prosthesis.

Comparative Effect of Incorporation of ZrO2, TiO2, and SiO2 Nanoparticles on the Strength and Surface Properties of PMMA Denture Base Material: An In Vitro Study.

Objective This study aimed to investigate the effects of nanoparticles (zirconium dioxide (ZrO2), titanium dioxide (TiO2), and silicon dioxide (SiO2)) on the flexural strength, impact strength, hardness, and wear resistance of the acrylic resin denture base material. Materials and Methods Acrylic resin specimens were fabricated in dimensions according to American Dental Association (ADA) specifications per test. Specimens were divided according to nanofiller into four groups; unmodified as control, ZrO2 (Z), TiO2, (T), and SiO2 (S) groups. Each one was subdivided into two subgroups according to nanoparticle concentrations; 3% and 7% (Z3, Z7, T3, T7, S3, and S7). A 3-point bending test, Charpy impact test, and Vickers hardness test were used for flexural strength, impact strength, and hardness measurements, respectively. Wear resistance was measured by the differences in surface roughness of tested specimens before and after the wear test. A scanning electron microscope was used to assess nanoparticle specifications and distributions and for fracture surfaces analysis. ANOVA, Bonferroni's post hoc test, and the Kruskal–Wallis test were applied for data analysis (α = 0.05). Results Regarding the flexural and impact strength, there was a statistically remarkable increase for all tested groups compared with the control group, except for the T7 and S7 groups (P value <0.001, effect size = 0.893) and (P value <0.001, effect size = 0.759), respectively. There was a statistically significant improvement in the hardness of all tested groups compared with the control group (P value <0.001, effect size = 0.67) except T3 and S3. Regarding wear, a statistically significant enhancement was noticed in the wear resistance of all tested groups (P value <0.001, effect size = 0.685), except for the T7 and S7 groups. Conclusion The flexural strength, impact strength, and wear resistance improved with both concentrations of ZrO2 and low TiO2 and SiO2 concentrations. The hardness increased with both concentrations of ZrO2 and high TiO2 and SiO2 concentrations.

Gessos pedra, usualmente empregados pelo cirurgião-dentista brasileiro, face a norma proposta pela Associação Dentária Americana

The main objective of this research was to analyse four dental gypsum products by brazilian dentists, according to the proposed American Dental Association specification for Dental Gypsum Products. (Six Draft) Iuated: consistency, setting time, compressive strenght, setting expansion and reproduction of detail. Only one the products tested (products tested (product D) met all the requirements. The other three products, (A, B and C) althought and reproduction of detail requirements, failed with regard to setting time and setting expansion requirements.

Effect of Incorporation of Different Concentrations of Silver Nanoparticles as an Antimicrobial Agent on the Flexural and Impact Strength of Heat-Cured Denture Base Resin

Abstract Aim This article evaluates the effect of incorporating different concentrations of silver nanoparticles as an antimicrobial agent on the flexural and impact strength of heat-cured denture base resin. Material and Methods A total of 80 specimens of polymethyl methacrylate resin were fabricated (40 for flexural strength and 40 for impact strength). Specimens were fabricated using stainless steel die of dimension 65 mm × 10 mm × 2.5 mm as per the American Dental Association specification no. 12, and 50 mm × 6 mm × 4 mm as per ISO 1567:1999 for flexural strength and impact strength, respectively, and were divided into four groups (A, B, C, and D) based on the concentrations of silver nanoparticles (0%, 2.5%, 5%, and 10%). The specimens were subjected to three-point bending test and Izod impact tester for testing flexural and impact strength, respectively. Data obtained was compiled and analyzed using one-way analysis of variance and post hoc tests. Results Results showed that for both the properties, maximum strength was observed in group A (control) followed by groups B and C, and minimum was observed in group D. A statistically significant difference in flexural strength was found among all the groups, whereas no statistically significant difference in impact strength was found among any of the groups. Conclusion Within the limitations of this in vitro study, it was concluded that though incorporation of silver nanoparticles exhibited no effect on the impact strength of heat cure denture base resin, it decreased the flexural strength, so it should be used cautiously.

Antimicrobial Activity, Physical Properties and Sealing Ability of Epoxy Resin-Based Sealer Impregnated with Green Tea Extract-Chitosan Microcapsules: An In-Vitro Study

Aim: To assess the effect of prepared green tea-chitosan microcapsules on the antibacterial efficiency against Enterococcus faecalis, the physical properties, and the sealing ability of resin-based endodontic sealer impregnated with these microcapsules. Materials and Methods: Green tea extract (GTE) and chitosan solution were prepared, then GTE was dissolved into this solution followed by precipitation of chitosan nanoparticles (CSNPs) loaded with GTE. Microcapsulation of GTE-CSNPs was performed and the solution was prepared (3 % w/v concentration). Characterization of microcapsules was conducted using Fourier-Transform Infrared Spectroscopy (FTIR), Zeta potential, and transmission electron microscope (TEM). The release of GTE at different pH values was evaluated. GTE-CSNPs solution was added to an epoxy resin-based sealer and the antibacterial activity was evaluated via direct contact test. The physical properties of the modified sealer were evaluated according to American Dental Association (ADA) specifications. Sealing ability was evaluated stereomicroscopically. Data were statistically analyzed. Results: FTIR and Zeta potential ensured the attachment between GTE and Chitosan. The particle size of CSNPs and GTE-CSNPs was around 20 nm, while microcapsules were greater than 1000 nm. A significantly higher percentage of GTE was released at pH 5 than pH 7.4, (𝑃 < 0.001). After sealer modification, the antibacterial evaluation showed significant decrease in optical density (𝑃 < 0.001). Also, the setting time, film thickness and microleakage were significantly decreased, however, the solubility was significantly increased (𝑃 < 0.001) but still within the acceptable limit of ADA specifications. Conclusions: GTE-Chitosan microcapsule is a proper natural candidate for improvement of sealer’s properties.

Comparative Evaluation of Surface Detail Reproduction and Dimensional Stability of Poly Ether, Vinyl Siloxane, and Vinyl Siloxane Ether Impression Materials: An In vitro Study.

Introduction:Impression making is an integral part of prosthetic dentistry. Development of material science has allowed integrating qualities of hydrophilic polyether and hydrophobic polyvinyl siloxane into a newer hybrid material, vinyl polysiloxane (VPS) ether. This study was aimed to compare the VPS ether with the polyether and polyvinyl siloxane in terms of accuracy and dimensional stability.Materials and Methods:Stainless steel dies with the American Dental Association specification 19 were made. Die has three horizontal and two vertical lines which are used for taking the impression. Two cross-points at the junction of the vertical lines with line 2 were marked as x and x' and served as beginning and end points of measurements for dimensional accuracy. Accuracy was evaluated 30 min after making each impression. If at least two of the three horizontal lines were reproduced continuously between cross-points, this impression was considered satisfactory. The specimens are poured with Type IV gypsum product and allowed to set completely for 24 h. Then, dimensional stability was measured in the model by measuring the distance between the two lines and comparing the distance with the measurement of line on metal die, which was used to make the impression.Results:The mean value obtained for light- and medium-bodied VPS ether was 0.05370 and 0.05330 and for light and medium-bodied polyvinyl siloxane was 0.06370 and 0.07150, respectively. The mean value for polyether monophase was 0.06430. Two-way ANOVA and post hoc test showed statistical significance.Conclusion:The newer VPS ether material showed good surface detail reproduction and dimensional stability when compared with polyvinyl siloxane and polyether.

Dimensional accuracy and surface detail reproduction of hydrophilic polyvinylsiloxane impression material tested under dry and moist salivary conditions: An In vitro study

Background: The dimensional accuracy and surface detail reproduction of impression materials play a major role in determining the extent to which indirectly produced prostheses and restorations have an acceptable fit. The purpose of the present study was to compare the dimensional accuracy and surface detail reproduction of hydrophilic polyvinylsiloxane (PVS) impression material tested under dry and moist salivary conditions. Methods: The study samples were assigned two groups based on the condition in which they were made. One group consisted of casts obtained from impressions made in dry condition (n = 12), while the other group consisted of casts obtained from impressions made in moist salivary conditions (n = 12). Impressions of the master model were made using hydrophilic PVS impression material by two-step putty-wash technique and working casts were obtained. Dimensional accuracy was measured by comparing the inter-abutment distance in each cast to the master model using a profile projector with an accuracy of 0.001 mm, while surface detail reproduction was evaluated using the American Dental Association specification No. 19 criteria of continuous replication of at least two of the three horizontal lines. Descriptive statistics such as mean and standard deviation were calculated for both the groups. Differences from the master model were analyzed by paired t–test, while one-way analysis of variance (ANOVA) was used for intergroup comparisons. P ≤ 0.05 was considered statistically significant. Results: One-way ANOVA revealed a highly significant difference in the dimensional accuracy of impressions made under moist conditions as against those which were made under dry condition (P

A Comparative Evaluation of Dimensional Accuracy and Surface Detail Reproduction for Polyvinyl Siloxane and Vinyl Siloxane Ether under Dry and Moist Conditions- An In-vitro Study

Introduction: The conventional impression procedure plays a major role in prosthodontics inspite of advancement in intra- oral scanning devices and 3D imaging procedures. Dimensional accuracy and surface detail reproduction are important for recording an impression. Aim: The study evaluated and compared the dimensional accuracy and surface detail reproduction of Polyvinyl Siloxane (PVS) and vinyl siloxane ether impression materials when used under dry and moist conditions. Materials and Methods: An in-vitro study was conducted in the Department of Prosthodontics, Rural Dental College, Pravara Institute of Medical Sciences, Loni, Ahmednagar, Maharashtra, India, for a period of two years from October 2018 to September 2020. A total of 60 impressions were made with PVS (Group A) and vinyl siloxane ether (Group B) under dry (A1, B1) and moist (A2, B2) conditions of stainless steel dies which had lines engraved on superior surface of the die. Using a Harloc’s Tool maker’s microscope, dimensional accuracy was measured by comparing the width of line Y in each impression. Surface detail reproduction was evaluated by American Dental Association (ADA) specification no. 19 where it stated continuous replication of at least any two lines out of the three lines inscribed on the die. Data analysis processing was performed in the SYSTAT version 12 (made by Crane’s software, Bangalore). Student’s unpaired t-test and Chi-square test were performed to determine statistical difference between PVS and vinyl siloxane ether where the level of significance was set at 5% and 1%. Results: The mean dimensional change and SD values for PVS under dry condition ranged from 21.93±2.46 to 22.40±2.89 (in mm). The mean dimensional change and SD values for PVS under moist condition ranged from 22.87±3.20 to 23.33±3.42. The mean dimensional change and SD values for vinyl siloxane ether under dry condition ranged from 21.93±3.61 to 24.73±5.20. The mean dimensional change and SD values for vinyl siloxane ether under moist condition ranged from 21.93±4.48 to 22.87±4.15. No statistical difference was found under dry and moist conditions within 2 hours and after 24 hours for both the materials. Conclusion: The study revealed no significant difference between dimensional accuracy and surface detail reproduction for PVS and vinyl siloxane ether. Both the materials can reproduce the details under dry and moist conditions satisfactorily and remained dimensionally stable till 24 hours after impression making.

EFFECT OF GOOD DENTAL CARE ON ORAL INFLAMMATION, CYTOKINES AND CHEMOKINES LEVELS IN RENAL TRANSPLANT PATIENTS: A RANDOMIZED CONTROLLED STUDY

Poor oral health results in inflammation and cytokine production in CKD and transplant patients. There is need to evaluate the benefit of good oral hygiene on renal transplant outcome. Pro-inflammation cytokines (TNF-A, ILB1, IL2, IL4), anti-inflammatory cytokines(IL6, IL10), chemokines (MCP1,2,3,4), Adiponectin and CRP are markers of status of inflammation. A randomized controlled trial was carried out amongst CKD patients going for renal transplantation. The randomization was done in 100 CKD patients going for transplantation. All patients had dental and oral examination (Type III clinical examination as per American Dental Association specifications and WHO oral health proforma, 2013) Group I (Interventional group) 50 CKD patients and Group II (Non-intervention group) - 50 patients of chronic kidney disease (CKD), going for transplantation were studied before and 3 months after transplantation. Group III (Control group) comprised of 50 healthy age, sex matched subjects. Intervention group did regular tooth brushing, use of dental floss along with use of mouth wash twice every day for 3 months after transplantation. They were given counselling sessions for good oral and dental care for a period of 3 months after transplant. Non-intervention group continued usual oral and dental care. Both groups had base line oral examination just before transplantation and at 3 months after transplant. The oral and dental findings specially the periodontitis score was compared between groups I and II and with the healthy controls. TNF-A, ILB1,IL2, IL4 IL6, IL10, MCP1,2,3,4, Adiponectin levels were measured on luminex platform (Bio-Plex Multiplex Immunoassay)and CRP (C- reactive protein) values were assayed(Latex Particle Immuno-turbidimetric method). These markers were assayed at baseline (before transplantation) and after 3 months. Comparison between Interventional and non-interventional groups at baseline and at 3months showed that periodontitis score and CRP levels significantly came down at 3 months in intervention group, Adiponectin levels were significantly reduced in non-interventional group while there was no significantly change in adenopectin levels in interventional group. CRP is regulated by interleukin-6 (IL- 6), and tumor necrosis factor-α (TNF-α). IL6, IL10 MCP1,2 values increased significantly by intervention. Rise in levels of IL1B was less in intervention group as compared to non intervention group. TNF-α increased significantly in Non-intervention group after 3 months. There was no effect on IL2,IL4 values remain in both groups, This is a report of results of a randomized control study in transplant recipients showing the benefits of good oral and dental care in relation to inflammation, Good oral and dental care in transplant recipients improved inflammation score and also reduced markers of inflammation which could have beneficial effect on post-transplant outcomes. There is need to include good oral and dental care and evaluation in CKD patients going for kidney transplantation.

Assessing the effect of ceramic additives on the physical, rheological and mechanical properties of conventional glass ionomer luting cement – An in-vitro study

AimTo evaluate the effect of the addition of conventional ceramics on the physical, rheological and mechanical properties of conventional glass ionomer luting cement. Materials and methods5%, 10%, 15% and 20% (w/w) of Enamel and Body conventional ceramic additives (E44 Enamel and B96/c4 Body) were reinforced in the two commercially available glass ionomer luting cement – GC Fuji I (GC Corporation Tokyo, Japan) and Ketac Cem Radiopaque (3M ESPE AG). Setting time, film thickness and compressive strength of the cement was measured according to the American Dental Association Specification number 96 for luting cement. Enthalpy change of the cement reaction was measured with the help of Differential Scanning Calorimetry analysis. Compatibility between the sizes of powder particles was measured with the help of a particle size analyzer. Results5% of ceramic additive could not improve much of the compressive strength. Compressive strength increased significantly (p < 0.05) with the addition of 10% of ceramic additive, beyond which, there was a gradual decrease in strength. Although the setting time and film thickness were also shown to increase due to the additive, the former did not exceed the limit specified by the American Dental Association Specification number 96 (2–8 min for setting time and 25 microns for film thickness). ConclusionAddition of 10% of conventional ceramics resulted in a significant increase in the compressive strength of GIC Luting Cement without any significant compromise in its setting time. The substantial increase in film thickness is a major limitation. Use of ceramic additives with physical properties compatible with that of the glass ionomer cement may aid in increasing the compressive strength without compromising its setting time or film thickness.