Acrylic Denture Base Material Research Articles

Evaluating the effect of the addition of Nano-cellulose fibers on certain properties of heat-cured acrylic resin denture base material

Background Polymethylmethacrylate (PMMA) is the most often used polymer for denture bases because to its inexpensive cost, lightweight nature, insolubility in mouth fluid, outstanding cosmetic features, and ease of repairability. However, various limitations such as insufficient surface hardness, low strength, brittleness, weak flexural strength, poor impact strength, and low fatigue resistance have a detrimental impact on acrylic resins. Method This research examined the impact strength, transverse strength, surface hardness, surface roughness, and color stability of heat-cured acrylic denture base material after 0.5% and 1% by wt. CNFs were added. The cellulose nanofibers were combined with a PMMA monomer for 5 minutes in a probe sonicator. One group of samples was made without cellulose nanofibers in PMMA, while two groups were prepared with 0.5% and 1% CNFs by weight, and tests of the impact strength, transverse strength, surface hardness, surface roughness, and color stability of the samples were carried out. The data were analyzed using descriptive statistics, including the mean and standard deviation, and bar charts were used to visualize the results. Sample interactions and fiber dispersion were assessed using FTIR and FE-SEM. Results Compared to the control group, 0.5% by wt. and 1% by wt. CNF improved the impact and transverse strength substantially, while shore D surface hardness was not improved. Hue (a) and chroma (b) were substantially influenced by CNF at 0.5% by weight compared to the control group, although surface roughness and color value (L) were not. Surface roughness, color value (L), and color hue (a) were substantially impacted by 1% compared to the control group; however, color chroma (b) was not. Conclusions This research found that 0.5% and 1% by wt. CNF in PMMA resin increased the impact strength, transverse strength, surface hardness, surface roughness, color value, hue, and chroma of heat-cured polymethyl methacrylate denture base material.

Water sorption and Solubility of Modified Heat Cured Acrylic Denture Base Material with Silver and Zirconia Nanoparticles

Water sorption and Solubility of Modified Heat Cured Acrylic Denture Base Material with Silver and Zirconia Nanoparticles

Gadolinium oxide Nanoparticles Infusion in Heat-Cured Acrylic Denture Base Material: Impact on Glass Transition Temperature and Mechanical Strength Enhancement

Introduction: Nano dentistry has paved the way for advanced therapeutic opportunities in various dental disciplines, particularly in the improvement of oral health. One area of focus is the enhancement of mechanical properties of dental materials, such as acrylic resins commonly used in denture base materials. Various strategies, including chemical corrections and the addition of particles, have been explored to augment the mechanical qualities. This study investigates the impact of incorporating Gadolinium oxide nanoparticles into heat-cured acrylic denture materials. Materials and Methods: The denture base was processed using a standardized approach, with the addition of Gadolinium oxide nanoparticles during the monomer phase. A total of 120 specimens were fabricated. 30 specimens for each test using 10 specimens for each nanoparticle concentration (Control 0%, 1%, and 1,5% nanoparticles). The nanoparticles were dispersed using sonication to ensure uniform distribution. The study assessed properties such as glass transition temperature using a differential scanning calorimeter, impact strength and transverse strength utilizing an Instron universal testing machine, and surface roughness via profilometer measurements. Scanning electron microscope also utilized. One way ANOVA was used to determine the mean differences. Results: The study revealed significant improvements in glass transition temperature, impact strength, and transverse strength. The peak values were often seen in the 1.5% wt. group. Surface roughness, however, showed non-significant changes with nanoparticle additions, possibly due to the minimal involvement of nanoparticles on the outer surface. Conclusion: Incorporating Gadolinium oxide nanoparticles into heat-cured acrylic denture base materials demonstrated notable enhancements in key mechanical properties. The findings suggest that nanoparticle additions contribute to increased strength and rigidity, as evidenced by improvements in impact and transverse strength. However, surface roughness remained largely unaffected. This study contributes valuable insights into the potential benefits of nanotechnology in optimizing dental materials for improved clinical performance and patient outcomes.

Physico-chemical and Mechanical Assessments of a New 3D Printed PMMA-Based Acrylic Denture Base Material

Background Three-dimensional (3D) printing is progressively being applied in the dental arena due to its time-saving potential and low cost, especially for the digital preparation of acrylic resin denture bases in the treatment of edentulism. Objective This study investigated the flexural strength, surface properties, water sorption, and solubility of a new poly (methyl methacrylate) (PMMA) resin denture base fabricated with a 3D printer (test group) and compared it with a conventional heat-cured resin (control group). Materials and Methods Sixty cuboid wax samples were prepared from two groups, with a thickness of 4 mm and dimensions of 10×80 mm. Then, half of the samples in each group were thermocycled to determine the strength, surface properties, water sorption, and solubility of the samples. Two-way ANOVA and independent t-test were used at a significance level of 0.05 after the normality of data in groups was tested with the Kolmogorov-Smirnov. Results Based on the obtained results, the flexural strength was higher in heat-cured resins than in the resin fabricated with the 3D printer. However, the flexural strength values in both resins were clinically acceptable (65 MPa) based on ISO standards. There was no significant difference in the mean flexural strength in the presence or absence of thermal stress for both groups. The layered structure was observed in the samples fabricated with two groups. However, the layering structure disappeared in all cases after polishing. The layering structure had no differences in the presence or absence of thermal stress. Mass change over time was observed for all groups. In the water sorption phase, the mass increased rapidly in the first 7 days, and then the increase rate decreased until it reached an equilibrium on day 21. In the desorption phase, the mass decreased steadily in the first 7 days, and then reduction was continued until equilibrium was obtained on day 21 of the dewatering process. Conclusion The 3D printer samples had greater water sorption, and no differences were found between the solubility of 3D printer samples and heat-cured samples. Heat-cured resin exhibited enhanced water sorption after thermal cycling, and 3D-printed materials displayed no significant change.

The Effect of some Natural Products as a Denture Cleansers on some Physical Properties of Acrylic Denture Base Material

The study aims to evaluate the effect of some commercially available natural products (soda+ vinegar, soda +thymol , saturated salt solution) in relation to the commercial denture cleansers (Protifex) ,on surface roughness and hardness dimensional accuracy of acrylic denture base materials. one hundred samples were prepared from heat activated acrylic resin denture base material, they are (1cm*1cm*2mm length, width and thickness respectively). After that, half of the samples for each group were immersed for ½ hr per day in the denture cleanser, the other half of the samples immersed for 8 hr per day in the denture cleanser through one month. The denture cleansers used are three solutions prepared freshly everyday for immersion of the samples. The surface roughness of the samples were tested by using Stylus profilometer(Talysurf 10, England), while the hardness of the samples were tested by using Rockwell hardness tester (Wolpert, Germany), the mean is taken for each group and evaluated by using one way analysis of variance test, Dunnet T-test to compare the groups. The results demonstrated that there were no significant differences in the surface roughness and hardness, but with significant difference between treats of length of acrylic resin denture base material and duration of immersion at (P=0.05). All the prepared natural solutions would be accepted in relation to effect on surface roughness , dimensional accuracy, and hardness of acrylic denture base material.

Effect of Beverage Solutions on Flexural Strength of PEEK CAD –CAM, 3D Printing Denture Base and Heat Cure Acrylic Resin Denture Base Materials

This research was to evaluate the effect of distilled water (D.W.), tea, coffee, and cola on flexural strength of PEEK CAD-CAM, 3D printing and heat cure acrylic resin denture base at different durations (6, 12and 24 days). Material used in this research are PEEK, 3D printing and Heat cure acrylic resin with dimension (64 × 10 × 3.3 ±0.2 mm, ISO 20795- 1:201320) for each tested material. Total number of samples are n= (195) samples, Control samples n=15, experimental samples n=180.The control samples were non immersed in beverage media. The experimental samples were immersed in beverage media (distilled water, tea, coffee, and cola) for evaluating the flexural strength at different time which are (6, 12 and 24 days), then all collecting data were statically analyzed by spss version 25, by means of Descriptive statistics, analysis of Variance (ANOVA) and Duncan multiple range tests at p ≤ 0.05. The beverage solutions had been non significantly decreased the flexural strength and this decreasing worst as the immer sion periods increased, the most decreasing in flexural strength o f PEEK denture base was achieved in 24 immersion days in cola (252.0960 MPa ±5.19825) followed by coffee (253.4360 MPa ± 6.60975) followed by tea(253.7780 MPa ± 6.44697) followed by distilled water (254.1420 MPa ±7.41318) as comparing with control(260.2420MPa ±5.08412), the most decreasing in flexur al strength of 3D printing denture base was achieved in 24 immersion days in cola (103.1680 MPa ±12.26532) followed by coffee (105.4360 MPa ±12.36951) followed by tea (10 7.4530MPa ±11.47399) followed by distilled water (109.1320 MPa ±11.66156) as comparing with control(119.7140 MPa ± 12.25421), the most decreasing in flexural strength of heat cure acrylic resin denture base was achieved in 24 immersion days in cola (118.5640MPa ±13.06764) follow ed by coffee (122.3640MPa ± 9.78213) followed by tea( 123.5600MPa ±14.05144) followed by distilled water (126.3620 MPa ± 11.35254) as comparing with control (134.6420 MPa ± 9.79330) at p ≤ 0.05. All beverage media had been negatively aff ected the flexural strength of all experimental materials and as t he immersion periods increased the affect became worst. The aggressive effect was in cola followed by coffee followed by tea and the least effect was in D.W. beverage media. The worst immersion period was 24 then 12 and 6 days. for all tests use but this affect was non significantly.

Comparative Evaluation to Surface Roughness of Modified Heat Cured Acrylic Resin by Zinc Oxide Nanoparticles and CAD/CAM Denture Base Materials - In Vitro Study

One of the most promising CAD/CAM approaches is milling denture base materials from highly condensed pre-polymerized resin discs. In an effort to overcome the disadvantages of acrylic resin denture base materials, nano-filler materials have been added as well as denture base chemistry adjusted to strengthen the denture base.This eliminates disadvantages associated with polymerization shrinkage compared to conventional heat-cured acrylic resin. Aim of this study: evaluate the surface roughness of PMMA acrylic resin after strengthening the denture- base by addition of zinc oxide nano-filler material to acrylic resin PMMA with concentration (1%) and compare with milled CAD/CAM and non-modified heat-cured PMMA denture base materials. Materials and methods: thirty specimens of acrylic resin PMMA were prepared and divided into three groups 10 specimens for each groups as follows; Control Group (Group1) without ZnO nanoparticles ; Group (2) with (1%) by weight of ZnO nanoparticles ; Group (3) milled CAD/CAM.Each specimen is of dimension ( 10 x 10 x 3 ) in mm and was fabricated using conventional processing method and milling the CAD/CAM blocks .Results: showed the lowest mean value was recorded by milled CAD/CAM (0.230 Ra) Then the non-significant reduction with mean value (0.312 Ra) by PMMA+ ZnO 1% and highest mean value of surface roughness was recorded by pure PMMA without additive (0.327 Ra).Conclusions: There were significant differences between control group PMMA and milled (CAD/CAM) with slight reduction of surface roughness of PMMA with (1%) Zno nanoparticles.

Effect of Beverage Solutions on Surface Roughness of PEEK CAD –CAM, 3D Printing Denture Base and Heat Cure Acrylic Resin Denture Base Materials

The Aim: The aim of this research was to investigate how distilled water, tea, coffee, and cola affected the surface roughness of poly ether ether ketone CAD-CAM, 3D printing, and heat cure acrylic resin denture bases at specific intervals (6 ,12days). Materials and Methods: Disk shape 10 mm (diameter) ×2 m m (thickness), manufactured from materials used which were PEEK, 3D printing and heat cure acrylic resin. Total number of samples are n= (75) samples, control samples not immersed in beverage media n= 15, experimental samples immersed in beverage solutions (distilled water, tea, coffee and cola) n=60 for evaluating the surface roughness at (6, 12 and 24 days) .Then all collecting data were statically analyzed by spss v ersion 25, by means of descriptive statistics, analysis of variance (ANOVA) and duncan multiple range tests at p ≤ 0.05. The Results: The results revealed a significant increase in surface roughness in all beverage solutions at p ≤ 0.0 5. Conclusions: All beverage solutions had a negative effect on surface roughness of all experimental materials, the surface roughness increased. cola had the most aggressive effect followed by coffee then tea and distilled water have the least ef fect.

Dimensional stability of acrylic denture base material after poly vinyl pyrrolidone addition

Problem Denture base dimensional changes were found with commercial theremocured acrylic resins. The dimensional stability of acrylic resin denture base is the main necessity effects the retention and stability of the denture. This study was conducted to measure the dimensional accuracy of experimental prepared material in comparison with control material before and after thermo cycling cured by water bath and microwave. In this stady the total (40) specimens of heat cure acrylic resin lower denture base were cured by water bath and microwave after addition poly vinyl pyrrolidone (PVP). (Experimental). Preparation of modified heat cured denture base acrylic resin was carried out by preparing of (PMMA) (80%) and poly vinyl pyrrolidone (PVP) (20%) and the liquid part composed of methyl methacrylate (MMA) monomer. Evaluation was made by measuring dimensional stability and accuracy. Distances were measured between (3) points marked on denture bases "AB, AC and BC" before and after thermo cycling for both control and experimental groups. The result of this study showed that there was no significant differences (p>0.05) between control and experimental groups at three point "AB, AC and BC" before and after thremocycling. Dimensional stability and accuracy was not influenced by addition of PVP to acrylic denture base resin before and after thermo cycling in both heat and microwave treatment.

Which metal surface treatment improves the bond strength between metal alloys and acrylic resin in removable partial dentures? A systematic review.

The union of the metal removable partial denture framework to the heat polymerized acrylic resin is related to prosthesis longevity. However, methods to enhance this bond are not clear to clinicians and dental laboratory technicians. The purpose of this systematic review was to identify which metal surface treatments best increase the bond strength between heat polymerized acrylic resin and removable partial denture alloys. This review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in the International Prospective Registry of Systematic Reviews (PROSPERO) database (CRD42022384926). Electronic searches were carried out independently, by 3 examiners in Medline/PubMed, Scopus, and Web of Science databases, and in the nonpeer-reviewed literature via ProQuest. The electronic searches resulted in 4143 articles, with 4055 after removing duplicates. After reading the titles and abstracts, 37 articles were selected for reading in full-text version, from which 6 articles were included. All studies evaluated materials for conventional acrylic resin denture base (heat polymerized), processed by water bath, bonded to metal. For the metal framework alloys, cobalt chromium (Co-Cr) alloys were used in 2 studies, titanium (Ti) in 2 studies, and Co-Cr and Ti in the other 2 studies. Different metal surface treatments were used as airborne-particle abrasion with aluminum oxide (particle sizes of 50µm, 110µm, and 250µm) followed by the primer application and the isolated use of the primer, compared to the absence of isolated intervention or airborne-particle abrasion of the metal surface. Among the different primers used, those based on 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) showed the highest acrylic resin-to-metal bond strength values. Airborne-particle abrading the metal with Al2O3 followed by applying a 10-MDP-based primer, increased the bond strength between metal framework alloys and heat polymerized acrylic resin denture base material.

SINGLE COMPLETE DENTURE WITH THE INCORPORATION OF A DENTURE TITANIUM MESH INTO THE DENTURE BASE AND METAL OCCLUSAL STOPS: A CLINICAL REPORT

The single complete denture is a complex prosthetic treatment that necessitates a comprehensive understanding of prosthetic rehabilitation for the loss of natural dentition. One of the main challenges encountered during the provision of successful single complete denture treatment is the repeated fracture of the prosthesis. To address this issue, incorporating denture titanium mesh into the denture base is proposed as an ideal solution to strengthen the prosthesis. Another common problem is the wearing off of acrylic denture teeth when opposing natural dentition. To mitigate this issue, the use of metal occlusal stops in the single complete denture is recommended. This clinical report presents a case of successful rehabilitation of an edentulous maxillary ridge using denture titanium mesh incorporated into the heat-cure acrylic denture base material, along with metal occlusal stops in a patient with an edentulous maxillary jaw.

Comparative evaluation of flexural strength of heat polymerized acrylic resin denture base material repaired with auto- polymerized acrylic resin using surface treated reinforcement materials – An in vitro study

: The purpose of this vitro study was to comparatively evaluate the flexural strength of repaired denture base resin using different surface treated reinforcement materials.According to ADA specification No. 12, typical heat polymerized acrylic resin specimens were created, and various repairs were made to them. Autopolymerizing resin was used for repair. The flexural strength was evaluated using the INSTRON universal testing equipment on a total of 90 samples (with 15 samples in each group). In this study the highest value of flexural strength was obtained for group in which the reinforcement was done with surface treated half round wires that were sandblasted, etched followed by application of alloy primer.: Specimens repaired with reinforcement increases flexural strength. Reinforcement with silanized woven roving e glass fibers showed significant increase in flexural strength compared to unreinforced specimens. There was no statistical difference between the samples repaired with sandblasted wires and etched wires group.

The Effect of Nano Hydroxyapatite on the Bond Strength of Acrylic Teeth Repaired to an Acrylic Resin Denture Base Using Two Types of Auto Polymerized Acrylic Resins

The insufficiently binder between acrylic teeth and dentures is considered to be the primary cause of teeth fractures from the dentures and is one of the disadvantages of acrylic denture base material. This research has been conducted to assess various concentrations of Nano hydroxyapatite addition on the shear bond between repaired acrylic teeth and polymer. One-hundred specimens of resin were split into two main subdivisions. 50 specimens were repaired with cold cured Duracryl Plus and the other 50 were repaired with a special type of acrylic O-cry1. Each one was sectioned into tested groups depending on (1%., 2%., 3%, and 5% by wt. of nano hydroxyapatite) incorporation and control group (0% of nano hydroxyapatite) with (n=10). The Universal testing machine was utilized for shear bond strength measurement. The obtained values were diffracted by t-test, ANOVA, and LSD-test. There was an increase in bond strength that repairing with O-cry1 than Duracryl Plus with a heightening in the bond strength, which was seen with incorporating nano hydroxyapatite into the acrylic resin with a significant difference between them. The 2% wt. Nano hydroxyapatite group demonstrated the maximum mean values, while those for the 5% wt. Nano hydroxyapatite group were recording minimum value with a significant difference between them. Repairing with O-cry1 recording better bond strength than Duracryl Plus acrylic. Furthermore, the addition of hydroxyapatite in Nano-form has successfully improved the “shear bond strength” of teeth to the PMMA at 2% wt. nano hydroxyapatite.

EFFECT OF ADDITION RAMIE AND COCONUT COIR FIBERS WITH DIFFERENT CONCENTRATIONS ON TENSILE STRENGTH OF ACRYLIC DENTURE BASE

Background: Acrylic denture base material has advantages such as good aesthetics, ease of repair, and affordable price, but this denture has mechanical properties, one of which is low tensile strength so fractures often occur during use. Utilization of natural fibers such as ramie (Boehmeria Nivea) and coconut coir (Coco Nucifera L) can be used as an alternative reinforcement for acrylic denture bases. Purpose: To determine the effect of adding ramie fiber and coconut coir fiber at different concentrations on the tensile strength of the acrylic denture base. Method: This study used a laboratory experimental method with a flat dumbell-shaped specimen with a size of 75 × 10 × 3 mm based on ISO 527-1 (2019). The specimens consisted of 42 plates which were divided into 7 groups, namely 6 specimens each group without fiber addition (control), with the addition of ramie fiber 1%, 2%, 3%, and the addition of coconut coir fiber 1%, 2%, 3%. Tensile strength testing using Universal Testing Machine (UTM), data were analyzed by One-way ANOVA test and Post Hoc LSD test. Result: The 3% ramie fiber addition group had the highest tensile strength (76.47 MPa), the 1% coconut coir fiber addition group had the lowest tensile strength (58.91 MPa). There was a significant difference in the results of the control group's tensile strength test and the addition of 3% ramie fiber and 1% coconut coir fiber (p-value < 0.05). Conclusion: The greater the concentration of ramie and coconut fiber additions, the higher the tensile strength value, although the tensile strength value in the coconut fiber addition group was lower than the control group and ramie fiber addition.

Tribological, microhardness and color stability properties of a heat-cured acrylic resin denture base after reinforcement with different types of nanofiller particles.

Polymethyl methacrylate (PMMA) is not an ideal material in all aspects, as it has poor mechanical and antimicrobial properties. The enhancement of the mechanical and physical features of PMMA-based material is highly required. The present study aimed to estimate the effect of adding different types of nanoparticle (NP) materials on the mechanical and physical features of heat-cured acrylic resin denture base material. A total of 120 samples were divided into 4 groups: the control group; the 5 wt% ZrO2 NPs group; the 5 wt% TiO2 NPs group; and the 5 wt% Ag NPs group. Each one was subdivided into 3 groups according to the test performed: the microhardness test; the abrasive wear test; and the color stability test. Then, the results of these tests were evaluated. The maximum mean value for the microhardness test was observed in the group treated with the addition of 5 wt% Ag NPs, followed by the 5 wt% ZrO2 NPs group, and finally the 5 wt% TiO2 NPs group. The lowest mean microhardness value was recorded for the control group. The maximum mean value for the abrasive wear test was attributed to the control group and the lowest mean value was related to the 5 wt% Ag NPs group. The maximum color change was noted in the 5 wt% Ag NPs group, followed by the 5 wt% ZrO2 NPs and 5 wt% TiO2 NPs groups. The lowest mean value for the color change was found in the control group. There was an increase in hardness and wear resistance in the group treated by adding 5 wt% Ag NPs, and the control group had the best color stability, followed by the 5 wt% TiO2 NPs group. However, a detrimental effect on color stability was observed when 5 wt% Ag NPs was added.

Evaluation of Two Denture Base Material on the Supporting Structures of Mandibular Tooth Supported Over Denture

Purpose: To compare the effect of thermoplastic resin and heat cured acrylic resindenture base materials on pocket depth and bone height around two mandibular caninessupporting mandibular tooth supported over denture. Subject and Methods: Tenpatients having completely edentulous maxillary ridge and bilateral canine in the lowerarch were selected. Root canal treatment and preparation were performed to obtainnon coping abutment with amalgam plugs that covered with over denture. Maxillarycomplete dentures were constructed for all patients. Patients were divided into two equalgroups. Group I: received thermoplastic mandibular over denture. Group II: receivedconventional heat cure acrylic resin mandibular over denture. Clinical and radiographic evaluation were performed at denture insertion , after 6month and after 9monthfor both mandibular over denture. Results: Statistical analysis of bone height showedthat group I (thermoplastic denture) has less bone resorption than group II (acrylicdenture) which was statically significant. Statistical analysis of change in pocket depthshowed that group I (thermoplastic denture) has less change in the pocket depth thangroup II (acrylic denture) which was not statistically significant. Conclusion: Withinthe limitation of this study thermoplastic over denture preserved pocket depth and boneheight more than conventional heat cured acrylic resin.

Evaluation of Two Denture Base Material on the Supporting Structures of Mandibular Tooth Supported Over Denture

Purpose: To compare the effect of thermoplastic resin and heat cured acrylic resindenture base materials on pocket depth and bone height around two mandibular caninessupporting mandibular tooth supported over denture. Subject and Methods: Tenpatients having completely edentulous maxillary ridge and bilateral canine in the lowerarch were selected. Root canal treatment and preparation were performed to obtainnon coping abutment with amalgam plugs that covered with over denture. Maxillarycomplete dentures were constructed for all patients. Patients were divided into two equalgroups. Group I: received thermoplastic mandibular over denture. Group II: receivedconventional heat cure acrylic resin mandibular over denture. Clinical and radiographic evaluation were performed at denture insertion , after 6month and after 9monthfor both mandibular over denture. Results: Statistical analysis of bone height showedthat group I (thermoplastic denture) has less bone resorption than group II (acrylicdenture) which was statically significant. Statistical analysis of change in pocket depthshowed that group I (thermoplastic denture) has less change in the pocket depth thangroup II (acrylic denture) which was not statistically significant. Conclusion: Withinthe limitation of this study thermoplastic over denture preserved pocket depth and boneheight more than conventional heat cured acrylic resin.

Flexural strength acrylic resin heat cured for denture base in soaking mouthwash containing siwak

Background: Teeth have an important role in a person, the most common cause of tooth loss is caries and periodontal disease. Tooth loss can be overcome by making dentures, removable denture components consist of dental elements, clasps, and bases. The denture base is part of denture that rests on soft tissues of oral cavity and is where denture elements are attached. One of the important mechanical properties for denture bases is flexural strength. Acrylic resin denture base material has disadvantage that it absorbs liquid and is porous so that food debris can settle and become a place for microorganisms to grow and multiply. This study aims to determine flexural strength of heat cured acrylic resin for denture base in immersing mouthwash containing siwak Method: this laboratory experiment used 12 linear specimens with a size (64 x 10 x 3.3 mm) ± 0.2 mm in accordance with ISO 20795-1:2013 which were divided into 2 groups, the first group was immersed in aquabidest (control), the second group was immersed in mouthwash containing siwak for 7 days. The data obtained were then tested using the Independent T-test Result: There was no significant difference (p > 0.05) in the flexural strength of heat cured acrylic resin Conclusion: From the research, there is no effect flexural strength of heat cured acrylic resin in soaking mouthwash containing siwak. The effect of mouthwash containing siwak on the flexural strength of heat-cured acrylic resin was not significant.

Effects of Different Surface Treatments of Woven Glass Fibers on Mechanical Properties of an Acrylic Denture Base Material

Silanized glass fibers are popular reinforcements of acrylic denture base materials. To increase the number of surface hydroxyl groups and to improve interfacial adhesion between the matrix and reinforcements, acid or base treatments of glass fibers are commonly performed before the silanization. However, limited data are available on the effect of these treatments on the mechanical properties of acrylic matrix composite materials used for denture base applications. In this work, before the silanization of a woven glass fiber fabric (GF) with 3-(trimethoxysilyl) propyl methacrylate, activation pretreatments using HCl and NH4OH aqueous solutions have been performed. To characterize the glass surface, FTIR spectroscopy was used. Specimens of cured acrylic denture base resin and composites were divided into five groups: (1) cured acrylic denture base resin-control group; (2) composite with non-silanized GF; (3) composite with silanized GF; (4) composite with NH4OH activated and silanized GF; (5) composite with HCl activated and silanized GF. The flexural and impact properties of specimens were evaluated by means of three-point-bending tests and Charpy impact testing, respectively. The residual reactivity of the samples was analyzed using differential scanning calorimetry. The results of mechanical testing showed that acid and base pretreatments of the glass fabric had a positive effect on the flexural modulus of prepared composites but a negative effect on their impact strength. Possible interfacial adhesion mechanisms and the diffusion control of isothermal cure reactions due to vitrification have been discussed.

Influence of Optiglaze Material on Wear Resistance of Thermoplastic Resin

Statement of problem: The wear resistance for flexible denture base material.
 Purpose: The purpose of the study was to measure the wear resistance, of flexible acrylic denture base material; after being coated with light-polymerized glaze material.
 Materials and methods: A total of (30) Thermoplastic resin specimens were divided into three groups according to the tests, each group consisted of 10 specimens (A) control group had no surface treatment, group (B) specimens surface was treated with Optiglaze materials after finishing and polishing; group (C) specimens was treated with Optiglaze materials after finishing only without polishing. Each specimen's weight loss was measured by comparing the weights before and after the wear test. Collected data were statistically analyzed using SPSS.
 Results: The results of this study showed the higher mean values for wear resistance was registered by (C) group which was 8.7420,followed by (B) group which was 7.3210,while the lowest mean value related to the (A) group which was 7.0907.
 Conclusion: Statistically wear values were lower for groups C & D and higher in group A.
 Clinical implications: This study may be useful in assisting dental professionals and technicians in selecting the best polishing and coating material for dentures. Coating flexible acrylic resin denture materials with an Optiglaze to improve wear resistance.