Water Sorption and Solubility of Vanillin-Incorporated Self-Curing Orthodontic Polymethylmethacrylate Resin

2021 ◽  
Vol 1020 ◽  
pp. 187-191
Author(s):  
Thongchai Poonpiriya ◽  
Pornrachanee Sawaengkit ◽  
Pornkiat Churnjitapirom ◽  
Sroisiri Thaweboon

Polymethylmethacrylate (PMMA) resin is one of the most commonly used materials for fabricating the base of removable orthodontic appliances. It is known that PMMA resin can promote the adhesion of microbes due to its surface porosity and from long-term use. Vanillin-incorporated PMMA resin has been reported to have antimicrobial effects against Candida albicans. However, the influence of vanillin incorporation on the water sorption and solubility of self-curing orthodontic PMMA resin has not been studied. Objective: To determine the water sorption and solubility of self-curing orthodontic PMMA resin incorporated with different concentrations of vanillin. Materials and methods: Three groups of self-curing orthodontic PMMA resin incorporated with 0.1% and 0.5% vanillin as well as PMMA without vanillin as a control were prepared with ten specimens per group. Water sorption and solubility tests were performed according to ISO 20795-2:2013 specifications. One-way ANOVA and Tukey’s multiple comparison tests at a p<0.05 significance level were used to analyse the data. Results: All three groups met ISO standard requirements. The means of water sorption values showed insignificant differences among the three groups even though the value of the 0.5% vanillin group tended to decrease. Water solubility of the 0.1% vanillin-incorporated group was not significantly different when compared with the control group whereas that of the 0.5% vanillin-incorporated group exhibited a significant lower value when compared with both control and 0.1% vanillin-incorporated groups. This suggests that increasing concentrations of vanillin would decrease the water solubility of PMMA resin. Conclusion: The incorporation of 0.5% vanillin into self-curing orthodontic PMMA resin could significantly reduce its water solubility and showed a trend of less water sorption property. Even with different vanillin concentrations, the water sorption and water solubility properties of PMMA resin were within the ISO standards. Nevertheless, further studies are recommended to determine the amount of residual monomer present in different concentrations of vanillin-incorporated PMMA resin.

2020 ◽  
Vol 853 ◽  
pp. 46-50
Author(s):  
Thongchai Poonpiriya ◽  
Pornrachanee Sawaengkit ◽  
Sroisiri Thaweboon ◽  
Pornkiat Churnjitapirom

Polymethylmethacrylate (PMMA) resin is the main polymeric material used in removable orthodontic appliances. However, it can promote the adhesion of microbes due to its surface porosity and from long-term use. While vanillin incorporated PMMA resin has been reported to have antimicrobial effects against Candida albicans, the influence of vanillin incorporation on the physical properties of self-curing orthodontic PMMA resin has not been studied. Objective: To determine the flexural strength and flexural modulus of self-curing orthodontic PMMA resin incorporated with vanillin in different concentrations. Materials and methods: Three groups of self-curing orthodontic PMMA with incorporated vanillin concentrations of 0.1%, 0.5% as well as PMMA without vanillin as a control were prepared with ten specimens per group. Flexural strength and flexural modulus were tested by a 3-point bending machine according to ISO 20795-2:2013 specifications. One-way ANOVA and Tukey’s multiple comparison tests at a p<0.05 significance level were used to analyse the data. Results: The 0.1% vanillin incorporated group met ISO standard requirements (flexural strength = 60.48 MPa, flexural modulus = 1756.60 MPa), while the 0.5% vanillin incorporated group failed to pass this standard (flexural strength = 46.94 MPa, flexural modulus = 1423.49 MPa). The means of both flexural strength and flexural modulus showed significant differences among the three groups. Increasing the concentration of vanillin would decrease the flexural strength and flexural modulus of PMMA resin. Conclusion: The incorporation of vanillin into self-curing orthodontic PMMA resin can affect its physical properties, namely flexural strength and flexural modulus. At a concentration of 0.1% vanillin incorporation, PMMA resin displayed physical properties within the ISO standards.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3453
Author(s):  
Abdulaziz Alhotan ◽  
Julian Yates ◽  
Saleh Zidan ◽  
Julfikar Haider ◽  
Carlos Alberto Jurado ◽  
...  

When PMMA denture base acrylics are exposed to oral environments for prolonged periods, the denture base absorbs water, which has a negative influence on the denture material and the degree to which the denture base will be clinically effective. This study assessed the water sorption, desorption, and hygroscopic expansion processes within PMMA denture-base resins reinforced with nanoparticles or fibre in comparison to the non-reinforced PMMA. The surfaces of the fillers were modified using a silane coupling agent (y-MPS) before mixing with PMMA. Group C consisted of specimens of pure PMMA whereas groups Z, T, and E consisted of PMMA specimens reinforced with ZrO2, TiO2 nanoparticles, or E-glass fibre, respectively. The reinforced groups were subdivided into four subgroups according to the percentage filler added to the PMMA resin by weight (1.5%, 3.0%, 5.0%, or 7.0%). Five specimens in disc shape (25 ± 1 mm × 2.0 ± 0.2 mm) were tested for each group. To assess water sorption and hygroscopic expansion, specimens from each group were individually immersed in water at 37 ± 1 °C for 180 days. The samples were then desorbed for 28 days at 37 ± 1 °C, to measure solubility. Water sorption and solubility were calculated using an electronic balance in accordance with ISO Standard 20795-1, and hygroscopic expansion was measured using a laser micrometre. Statistical analysis was undertaken at a p ≤ 0.05 significance level using a one-way ANOVA followed by Tukey post-hoc tests. The results demonstrated that the values of sorption (Wsp), mass sorption (Ms%), and % expansion within the tested groups reached equilibrium within 180 days. A noticeable difference was observed in groups Z and E for (Wsp)/(Ms%) compared to the Group C, but this was not significant. However, the difference between Group C and Group T for these measurements was significant. Non-significant differences also existed between each respective reinforced group and the control group in terms of hygroscopic expansion % values. During the 28-day desorption period, there were no differences in the values of solubility (Wsl)/mass desorption (Md%) between Group C and each of the reinforced tested groups. The findings indicate that the inclusion of ZrO2 nanoparticles or E-glass fibres does not increase the water solubility/sorption of the PMMA. However, modifying the PMMA with TiO2 did significantly increase the water sorption level.


2013 ◽  
Vol 18 (6) ◽  
pp. 26-30 ◽  
Author(s):  
Glaucio Serra ◽  
Liliane Siqueira de Morais ◽  
Carlos Nelson Elias

INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length) were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.


2018 ◽  
Vol 88 (5) ◽  
pp. 530-537
Author(s):  
E. Erin Bilbo ◽  
Steven D. Marshall ◽  
Karin A. Southard ◽  
Verrasathpurush Allareddy ◽  
Nathan Holton ◽  
...  

ABSTRACT Objectives: The long-term skeletal effects of Class II treatment in growing individuals using high-pull facebow headgear and fixed edgewise appliances have not been reported. The purpose of this study was to evaluate the long-term skeletal effects of treatment using high-pull headgear followed by fixed orthodontic appliances compared to an untreated control group. Materials and Methods: Changes in anteroposterior and vertical cephalometric measurements of 42 Class II subjects (n = 21, mean age = 10.7 years) before treatment, after headgear correction to Class I molar relationship, after treatment with fixed appliances, and after long-term retention (mean 4.1 years), were compared to similar changes in a matched control group (n = 21, mean age = 10.9 years) by multivariable linear regression models. Results: Compared to control, the study group displayed significant long-term horizontal restriction of A-point (SNA = −1.925°, P &lt; .0001; FH-NA = −3.042°, P &lt; .0001; linear measurement A-point to Vertical Reference = −3.859 mm, P &lt; .0001) and reduction of the ANB angle (−1.767°, P &lt; .0001), with no effect on mandibular horizontal growth or maxillary and mandibular vertical skeletal changes. A-point horizontal restriction and forward mandibular horizontal growth accompanied the study group correction to Class I molar, and these changes were stable long term. Conclusions: One phase treatment for Class II malocclusion with high-pull headgear followed by fixed orthodontic appliances resulted in correction to Class I molar through restriction of horizontal maxillary growth with continued horizontal mandibular growth and vertical skeletal changes unaffected. The anteroposterior molar correction and skeletal effects of this treatment were stable long term.


2011 ◽  
Vol 35 (4) ◽  
pp. 433-436 ◽  
Author(s):  
Asli Topaloglu-Ak ◽  
Fahinur Ertugrul ◽  
Ece Eden ◽  
Mustafa Ates ◽  
Hakan Bulut

Objective: This study investigates the effect of fixed and removable orthodontic appliances among children on salivary Streptococcus mutans, Lactobacillus sp. and Candida albicans. Study Design: The study was conducted on 69 patients aged between 6-17 years who used fixed or removable orthodontic appliances. Five ml samples of unstimulated saliva from each patient were collected at baseline and at the 1, 3 and 6 month periodic controls. Samples were diluted and plated on Mitis Salivarus Agar (MSA), Man Rogosa Sharp Agar (MRS) and Saboroud Dextrose Agar (SDA). The growths on the plates were examined under a stereomicroscope. Numbers of colony forming units (CFU) per plate were counted. For statistical analysis,the paired t test and Chi-Square were used. Results: S mutans and Lactobacillus sp counts increased significantly 6 months after the insertion of fixed/removable orthodontic appliances in the oral cavity. A significant increase for C albicans presence was noted after 3 months compared with baseline for fixed appliances.Conclusion: Long-term utilization of orthodontic appliances may have a negative effect on microbial flora and increase the risk of new carious lesions and periodontal problems. Patients should be recalled within short time intervals to be motivated for oral hygiene during their orthodontic therapy.


2018 ◽  
Vol 39 (1) ◽  
pp. 187
Author(s):  
Lorena Chaves Monteiro ◽  
José Dantas Ribeiro Filho ◽  
Waleska De Melo Ferreira Dantas ◽  
Bruna Maria Ribeiro ◽  
Micheline Ozana da Silva ◽  
...  

The objective of this study was to assess the effects of an electrolyte and energy repository on the hematologic and biochemical variables of horses after a polo game and compare them to the effects of a commercial electrolyte repository and water. Twelve healthy horses, aged 5 to 10 years, mean body weight 356.25 ± 25.6 kg and in training for polo games, were randomly divided into three groups of four animals each and received one of three treatments. Animals participated in a 7-minute polo game. At the end of the match, they were taken to individual stalls where they received treatments for spontaneous hydration for 6 hours. Treatments were Hydroelectrolytic and Energy Repository (RHE) containing sodium, chloride, potassium, calcium, magnesium, dextrose, maltodextrin and, sucrose; and Commercial Paste (PCO) containing calcium, fructooligosaccharides, glycine, magnesium, potassium, sodium, and ad libitum water. The control group (Water) received water. Blood samples were collected as follows: just before the beginning of exercise (T0), immediately after exercise (T1), 3 hours after the end of exercise (T3), and 6 hours after the end of exercise (T6). The volume of voluntary intake was measured at T3 and T6. Packed cell volume and serum concentrations of sodium, potassium, chloride, calcium, magnesium, phosphorus, creatinine, total protein, plasma glucose, and lactate were measured. Data were submitted to descriptive statistics (mean ± standard deviation), Lilliefors and Cochran & Bartlett tests, analysis of variance (ANOVA), and Tukey or Duncan tests at a 5% significance level. The net volume ingested by the RHE group was higher than the PCO and control groups. In all groups, a reduction in chloride concentration and increases in packed cell volume, protein, creatinine, glucose, and lactate concentrations were observed in T1. These variables returned to the values found at T0 throughout the rehydration phase (T3 and T6). It is concluded that the ingestion of the hydroelectrolytic energy repository does not cause alteration in the biochemical profile of the animals.


2019 ◽  
Vol 801 ◽  
pp. 9-14 ◽  
Author(s):  
Sroisiri Thaweboon ◽  
Boonyanit Thaweboon

Removable orthodontic appliances made of poly methyl methacrylate (PMMA) resin are commonly used after complete orthodontic treatment to keep teeth in the right position and prevent the shift out from the alignment. The use of these appliances can place patients at increased risk of dental caries through the biofilm accumulation ofStreptococcus mutans, caries-associated bacteria, on the surfaces of appliance themselves. Moreover, their rough surfaces or intrinsic porosities of PMMA enhance a condition for plaque aggregation, altering the oral microflora and limiting the washing out action of saliva on teeth and mucosal tissues, subsequently bringing about enamel demineralization and gingival inflammation. Cleaning by brushing or using chemical disinfectants is necessary for hygiene maintenance of the appliances, but requires patient cooperation, which is uncertain. Vanillin is a natural phenolic aldehyde which is used widely as a flavoring agent in various foods. It has been reported by many studies to exhibit antimicrobial activity. The aim of the present study was to evaluate antimicrobial property of vanillin-incorporated orthodontic PMMA resin onS. mutansbiofilm formation. The self-curing orthodontic PMMA resin samples (SCG Chemicals, Thailand) were prepared according to the percentage of vanillin incorporation (0%, 0.1% and 0.5% vanillin). Another group of commercial resin samples without vanillin (Dentsply Caulk, USA) was prepared in the same manner. All samples were coated with sterile unstimulated saliva collected from three healthy adult volunteers at 37 °C for 60 min. TheS. mutansbiofilm formation was done with the 107colony forming unit (CFU)/m of bacterial suspension in 96-well plate and incubated at 37°C in 5% CO2 atmosphere for 24 h. The amount of biofilm was quantified by Cell Counting Kit WST-8 (Dojindo Molecular Technologies, USA) at 450 nm. All tests were performed in triplicate on three separate occasions. One-way ANOVA and Turkey’s test were used for the statistical analysis. A significant inhibitory effect was observed in 0.5% vanillin incorporated samples at 48 h compared with 0% vanillin and commercial samples. The percentage of biofilm reduction was 30%. In conclusion, the incorporation of vanillin to self-curing orthodontic PMMA resin could significantly inhibit biofilm formation ofS. mutans. Using this PMMA resin, removable orthodontic appliances with antimicrobial property can be applied to prevent dental caries or tooth demineralization in orthodontic patients.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1922
Author(s):  
Iwona Ewa Kochanowska ◽  
Katarzyna Chojnacka ◽  
Edyta Pawlak-Adamska ◽  
Marcin Mikulewicz

Background: Due to the long-term contact with metallic elements of orthodontic appliances, the potential influence of released metal ions on living organisms and the type of induced changes was investigated. Materials and Methods: Twenty-four young domestic pigs classified in two groups (experimental and control) were chosen as the object of this study. In the experimental group of animals, two metal plates consisting of orthodontic bands representing the mass of orthodontic appliance were mounted on the internal side of the cheek for six months. The liver, lung, and brain samples were taken post mortem from animals of both groups. The gene expression of two isoforms of metallothionein (MT-1 and MT-2) were investigated using the qPCR technique. Protein expression was confirmed by the Western blot and ELISA techniques. Results: The differences in metallothionein concentrations were observed in the lung and brain in the the group of experimental animals, but not in the liver. The expression of MT-1 and MT-2 genes in the experimental vs. control group (respectively) was as follows: lung MT-1 1.04 vs. 1.11, MT-2 0.96 vs. 1.05, liver MT-1 0.89 vs. 0.91 vs. 1.12, MT-2 0.91 vs. 1.05, brain MT-1 1.24 vs. 1.20, and MT-2 0.955 vs. 0.945. These results were confirmed by gene activity, which was tested by qPCR. This increased the activity of metallothionein genes in the lungs and brain as a consequence of the release of metal ions into these tissues. The possible effects of detected change in metallothionein-2 gene expression could be the alteration of physiological functions of lung tissue. Conclusions: The effect of long-term exposure to metal orthodontic appliances on metallothioneins gene expression, as well as the induction of protein synthesis was proved.


Author(s):  
P.A. Zhelezny ◽  
◽  
S.P. Zhelezny ◽  
Yu.K. Zheleznaya ◽  
A.P. Zheleznaya ◽  
...  

Long-term clinical observations on the treatment and rehabilitation of 117 children with tumors and tumor-like formations of the maxillofacial region are presented. To replace jaw defects, we used transplants preserved in various ways: frozen — in 48 patients, preserved in 0,5% formalin — in 7 patients, Kostma — in 7 pati¬ents, Deprotex — in 28 patients, Orgamax — in 27 patients. In the postoperative period, orthopedic and orthodontic rehabilitation of patients was carried out using removable and non-removable orthodontic appliances and dental implant systems. In the near term, no complications were revealed in 108 patients; consolidation of the graft with the bone bed occurred. 9 patients developed a purulent inflammatory process with allograft sequestration. The follow-ups of the patients showed that after transplantation, the allograft was gradually resorbed and replaced with a full-fledged organotypic regenerate within a period of 1,0 to 3 years. During the long-term up to 10 years follow-up, 92 patients (89,3 %) obtained good anatomical, functional and aesthetic results of rehabilitation, characterized by full restoration of the function of the dentition and facial aesthetics. In 11 patients (10,7 %), the results were satisfactory.


VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  

Background: Prostanoids are used in the treatment of Raynaud’s phenomenon and acral perfusion disorders secondary to collagenosis. In subjective terms, intravenous administration of these agents produces success in more than 50% of patients. The therapeutic outcome of clinical administration of alprostadil or iloprost may vary from individual to individual. Patients and methods: The following variables were analysed in a cross-over study in 27 patients with collagenosis and Raynaud’s phenomenon: plasma viscosity and erythrocyte aggregation (rheological variables), partial pressure of oxygen and laser Doppler flowmetry in the finger region, and lymphocyte phenotyping and interleukin (IL) determinations (immunological variables). Results: Laser Doppler flowmetry revealed significant differences between patients with secondary Raynaud’s phenomenon and a control group of 25 healthy subjects. Laser Doppler readings did not change significantly as a result of the treatments. Therapy with iloprost produced a reduction in IL-1beta, L-selectin (CD 62 L) and IL-6. Conclusion: The change in immunological variables due to iloprost may explain the long-term effects of prostaglandins in the treatment of Raynaud’s phenomenon. From our results it is not possible to infer any preference for iloprost or alprostadil.


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