Antifugal action of some natural oils on acrylic resin denture base materials. In the case of the polyamide specimens, a wax sprue was attached to the metallic pattern before investing, while in the PMMAs case the conventional denture flasking technique was followed. 2012;12(2):295-300. E* parameter increased with the cycles up to 2.0-2.5 units at the end of the experiment, with the microwaved groups presenting the highest values. From each material, sixteen specimens were constructed, which were divided into two groups (n=8). The present study was conducted at three dental centers, where patients selected were those who were not happy with their existing complete / complete [Figure 1], complete / partial [Figure 2], partial / partial dentures [Figures [Figures33 and and4],4], made of conventionally used poly methyl- methacrylate denture base material and were in search of some substitute. In the present study, all the 18 cases were prolonged denture wearers who had undergone frequent adjustments such as relining and rebasing of their old dentures, which were not functionally comfortable. Group (Experimental): specimens were placed in a cup filled with 200 ml of distilled water and in a microwave device (Siemens-Electrogerte HF1210, Siemens AG, Munich, Germany) operating at 450 W for 3, 7, 14, 28, 56, 84, 112, 140, 168, 196, and 224 cycles of 3 minutes2828 - Senna PM, Sotto-Mattior BS, Silva WJ, Del Bel Curry AA. The effect of repeated microwave irradiation on the dimensional stability of a specific acrylic denture resin. Eighteen cases who were not satisfied with their conventional acrylic dentures were selected. 2009;37(9):666-72. All the cases were evaluated for the following parameters [Tables [Tables11 and and2]:2]: mucosal irritation, halitosis, ease of insertion and removal and fractures / cracks frequency and comfort in function. Dimensional stability of dentures during processing and while in-service is of great importance for denture fit and patient satisfaction. There was no fracture observed in new flexible dentures. 2015;24(1):25-31., involving within changes numerous other factors besides processing and microwave disinfection. Influence of microwave disinfection on the dimensional stability of intact and relined acrylic-resin denture bases. 2009;101(3):205-13., but there is little information on the effect on color of microwave irradiation as a method of disinfection. Antifugal action of some natural oils on acrylic resin denture base materials. J Mater Sci. - Wroe R, Rowley AT. This observation was reported at grades 4 and 2 by one patient each, respectively, with new flexible dentures. J Dent. - Al- Sumaidae RR. Effect of microwave disinfection on mechanical properties of denture base acrylic resin. Evidence for non-thermal microwave effect in the sintering of partially stabilized zirconia. 1983;11(1):80-8. The effects of microwave disinfection on the dimensional stability of denture base materials have been extensively studied, and some of them showed significant dimensional changes22 - Alkhodary MA. 21 - Makila E, Honka O. J Prosthodont.

Accessibility 25 - Polyzois GL, Zissis AJ Yannikakis SA.

This study revealed a significant effect of the microwaving action on initial shrinkage, color and translucency of polyamide and PMMA denture base materials, which behaved differently. - Senna PM, Silva WJ. 2015;73(5):353-63. It also has a high creep resistance and fatigue endurance along with the excellent wear characteristics and solvent resistance. Table 1b shows that with old dentures six patients observed halitosis at grade 4 which was highest and five patients observed it at grade 3. sharing sensitive information, make sure youre on a federal J Dent. The acrylic denture base prostheses have their own advantages and disadvantages.

Sample size was decided in a priori estimation using G*Power software v.3.1.9.2 (Universitt Kiel, Kiel, Germany), and an effect size (f) of 0.60, almost half the value found in a previous study2323 - Polychronakis NC, Polyzois GL, Lagouvardos PE, Papadopoulos TD. 33742. 2014;60(4):3737-42. The flexible dentures were found to fare significantly better as compared to the conventional methyl methacrylate dentures on the parameters taken in the present study. When questioned about the preference among the two types of denture base material, 100% patients preferred the flexible dentures over the customary methyl methacrylate dentures. 1979;6(2):199-204. 2015;73(5):353-63. 1992;20(6):370-4. to the active sites of the polymer chain2020 - Lamb DJ, Ellis B, Priestley D. The effects of process variables on levels of residual monomer in autopolymerizing dental acrylic resin. 2012;12(2):295-300.,1111 - Duyck J, Vandamme K, Muller P, Teughels W. Overnight storage of removable dentures in alkaline peroxide-based tablets affects biofilm mass and composition. TP values decreased for both materials when irradiated, and reached a decrease of 18.5%-22.5% after 224 cycles. 18 - Hong G, Murata H, Li Y, Sadamori S, Hamada T. Influence of denture cleansers on the color stability of three types of denture base acrylic resin. Influence of microwave disinfection on the dimensional stability of intact and relined acrylic-resin denture bases. Al-Rafidain Dent J. Phillips Science Of Dental Materials; p. 238.

Since ages, polymethyl methacrylate (PMMA) has been used to fabricate the dentures and when facilities are available, metal cast / metal frame / metal base dentures are also fabricated to restore the defects. Linear dimensional changes of denture base and hard chair-side reline resins after disinfection. J Mech Biomed Mater. 2011;20(8):632-8. Previous studies examined the effects of denture cleansers on the color stability of denture base materials1010 - Durkan R, Ayaz EA, Bagis A, Gurbuz A, Ozturk N, Korkmaz FM. J Prosthodont. Effectiveness of microwave sterilization on three hard chairside reline resins. However, de-bonding of the teeth was observed in four cases after 10 and 11 months of use and was attributed to faulty de-waxing procedure, where wax was not completely removed from the mechanical undercuts (Diatorics) and the molten flexible denture base material could not flow into the areas created for mechanical locking.[9]. Color stability of resins and nylon as denture material in beverages. 2010;3(7):480-7. Anusavice KJ. 1996;127(5):672-80.. Several methods of disinfection have been suggested33 - American Dental Association Council on Scientific Affairs and Council on Dental Practice. Polychronakis, et al.2323 - Polychronakis NC, Polyzois GL, Lagouvardos PE, Papadopoulos TD. The change in Valplast control group was mainly due to the decrease in L* and in Vertex to the decrease in L* with a small increase in a* (Figures 4-6). Acta Stomatol Croat. Acrylic dentures, denture base materials, flexible dentures. Photosensitization of in vitro biofilms formed on denture base resins. (EN). J Prosthet Dent. Most of the changes were negative, indicating a decrease when the number of cycles was increased. 1999;81(4):375-9. 1999;81(4):375-9.. Am J Dent. 2006;102(2):1821-6. 6 - Consani RL, Iwasaki RY, Mesquita MF, Mendes WB, Consani S. Effect of repeated simulated disinfections by microwave energy on complete denture base adaptation. Photosensitization of in vitro biofilms formed on denture base resins. 2011;20(8):606-12. Prosthodontic planning & observations regarding this material are discussed on various parameters. Only two cases (11%) reported halitosis, four cases (22.2%) reported debonding of teeth from the dentures after 10 and 11 months, respectively. The .gov means its official. Comparative effects of denture cleansers on physical properties of polyamide and polymethyl methacrylate base polymers. Initial finishing was performed with 600 grit, 800 grit and 1200 grit waterproof silicon carbide paper in an Ecomet III polishing equipment (Buehler Ltd, Evaston, III, USA) while polishing was performed using a high gloss agent (KMG, Candulor AG, Zurich, Switzerland) on a white cotton yam wheel polishing brush (Bur Dental, Guangzhoo, China). J Prosthet Dent. 2009;37(9):666-72. Looking at the graph of Figure 3, it is seen that the change for the Vertex was initially close to that of Valplast, but in two weeks reached the level of its total change and remained there until the end of 224 cycles (7.5 months). Within control baths, both materials retained their initial TP values (their loss was only 0.010%-0.012%), but in the microwave oven, TP values decreased significantly (18.7%-22.5%). Int J Prosthodont. Stay informed of issues for this journal through your RSS reader, Text Palate shape, denture base thickness and teeth presence are some of the factors that lead to the final effect. 2006;102(2):1821-6. or to the higher amount of grain boundaries existing in the PMMA material. Effect of cleansing methods on 3-D surface roughness, gloss and color of a polyamide denture base material. In spite of various advancements and research in dental materials, training, and techniques across the world, the fracture, foul smell, and allergy to PMMA could not be avoided. Comparative effects of denture cleansers on physical properties of polyamide and polymethyl methacrylate base polymers. Some problems with these prostheses are difficult to address, such as insertion in undercut areas, brittleness of methyl methacrylate which leads to fracture, and allergy to methyl methacrylate monomer.[2]. Influence of microwave disinfection on the dimensional stability of denture reline polymers.J Prosthodont. (Case 1 and 2) Complete/complete flexible dentures, (Case 3) Complete / partial flexible denture, (Case 4) Partial / partial flexible denture, (Case-5) Partial /Partial flexible dentures. 2014;48(4):279-84.,2727 - Senna PM, Silva WJ. However, this change was not considered important since it was below the clinically perceptible levels of 2.799 - Douglas RD, Steinhauer TJ, Wee AG. However, both denture base materials under microwaving disinfection cycles exhibited a small shrinkage at first which later became greater for the Vertex (PMMA) and decreased slightly for the Valplast (polyamide). 2015;24(1):25-31. Egypt Dent J. J Prosthodont. Although, cast partial denture has been a viable substitute, the requirement of high skill in preparation, technique-sensitive casting procedure, heavy weight, and visibility of metal clasp made it more difficult and cumbersome alternative and net results have not been encouraging. 1996;127(5):672-80. Measurements were performed at a right angle with the surface of the specimen, at three different sites in the middle area of the specimen for obtaining a mean value. 2013;41(12):1281-9. 2012;12(2):295-300. will also be available for a limited time. 2013;30(1):26-31. (2010) reported no significant effect on dimensional stability. St Louis: Mosby; 1997.. The Once trained in good oral habits, halitosis started disappearing in these two cases also. Influence of microwave disinfection on the dimensional stability of denture reline polymers.J Prosthodont. Shrinkage effects of microwaving on PMMA denture base materials are similar to the effects in the studies of Gonalves, et al.1414 - Gonalves AR, Machado AL, Giampaolo ET, Pavarina AC, Vergani CE. Trend analysis on the above values indicated a rather logarithmic regression line of change along the number of cycles, and a much higher coefficient of determination (R2) for the microwaved group than in the control group, for both materials (Table 2). - Durkan R, Ayaz EA, Bagis A, Gurbuz A, Ozturk N, Korkmaz FM. Gerodontology. Egypt Dent J. (English), https://doi.org/10.1590/1678-7757-2017-0536. Int J Prosthodont. Intraoral determination of the tolerance of dentists for perceptibility and acceptability of shade mismatch. - Basso MF, Giampaolo ET, Vergani CE, Machado AL, Pavarina AC, Ribeiro RC. 15 - Hamouda IM, Ahmed SA. The specimens length changed since the first cycles (Figure 2). 2014;60(4):3737-42.,2727 - Senna PM, Silva WJ. The new PMC design is here! After polymerisation, flasks were bench-cooled before specimens were removed from them. J Am Dent Assoc. As per questionnaire, the results were compiled and the data were analyzed by a nonparametric test, Wilcoxon signed ranks test to study the change in various indices of functional observations and to draw the conclusion. Before injecting polyamide into the gap, the material was heat-melted at 280C for 11 minutes in a digital melting Valplast furnace. 2013;30(1):26-31.. Microwave irradiation of dentures is performed by either the wet (placed in a water bath) or dry disinfection method. The most commonly used material for the fabrication of complete / partial dentures so far has been PMMA. J Prosthet Dent. Most probably, the decrease can be explained by the increase in roughness due to microwave irradiation on PMMA and polyamide material (Figure 8), as Polychronakis, et al.2323 - Polychronakis NC, Polyzois GL, Lagouvardos PE, Papadopoulos TD. (2014) who found that PMMA showed linear shrinkage up to -1.16% following disinfection of seven 6 minutes cycles in a microwave oven at 650W. Corresponding address: Nick Polychronakis.

2013;29(11):1091-7. Both resins tested in this study exhibited a statistically significant change of their initial color after microwave disinfection and reached the level of almost 2.5 units of * at the end of 224 cycles. It is imperative that such prostheses be disinfected, at the dental surgery or laboratory, to reduce risks of cross-contamination and to comply with infection control guidelines33 - American Dental Association Council on Scientific Affairs and Council on Dental Practice. - Coimbra FC, Salles MM, Oliveira VC, Macedo AP, Silva CH, Pagnano VO, et al. Adding denture cleanser to microwave disinfection regimen to reduce the irradiation time and the exposure of dentures to high temperatures. Antimicrobial efficacy of complete denture cleansers. Acta Stomatol Croat. 9 - Douglas RD, Steinhauer TJ, Wee AG. Influence of microwave disinfection on the dimensional stability of denture reline polymers.J Prosthodont. Effect of microwave disinfection on mechanical properties of denture base acrylic resin. Anthony DH, Peyton FA. Al-Rafidain Dent J. FOIA Nishigawa G, Matsunaga T, Maruo Y, Okamoto M, Natsuaki N, Minagi S. Finite Element Analysis of the Effect of the Bucco-Lingual Position of Artificial Posterior Teeth under Occlusal Force on the Denture Supporting Bone of the Edentulous Patients. 1995;8(2):150-4. Antimicrobial efficacy of complete denture cleansers. The figure shows that TP values for the Vertex material are initially higher than those of Valplast and remained the same for both materials of the control groups at all cycle intervals. bacteria, fungi or viruses) turns them into sources of infection risk that may affect denture wearers and dental professionals. (2011), although in their studies the irradiation protocol was different (650 W for 6 minutes or 900 W for 3 minutes per cycle). Furthermore, bleaching of dental base materials, unpleasant taste to patients and oral tissue reactions are some of the adverse effects of chemical disinfectants1515 - Hamouda IM, Ahmed SA. The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials. Also, the postinsertion maintenance is easy, which makes it a very user- friendly denture base material.[7,8]. 11 - Duyck J, Vandamme K, Muller P, Teughels W. Overnight storage of removable dentures in alkaline peroxide-based tablets affects biofilm mass and composition. Infection control recommendations for the dental office and the dental laboratory. J Prosthodont. The effect of repeated microwave irradiation on the dimensional stability of a specific acrylic denture resin. Effect of microwave disinfection on mechanical properties of denture base acrylic resin. The length of each specimen was measured using a digital caliper calibrated to 0.03 mm (Mitutoyo Inc., Tokyo, Japan). The change was positive (Length increased) for the control groups and remained stable for the rest of the cycles, but for the microwaved groups the change was negative (Length decreased) and became more negative for the Vertex material and less negative for the Valplast material (Figure 2). 2011;20(8):606-12.,3131 - Wagner DA, Pipko DJ. 5 - Coimbra FC, Salles MM, Oliveira VC, Macedo AP, Silva CH, Pagnano VO, et al. All measurements were carried out by the same investigator. government site. [3,4] Once the casting was completed, the flask was allowed to bench cool .The sprues were removed and dentures polished. J Dent. The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. - Makila E, Honka O. Learn more They were provided flexible dentures along with a questionnaire to precisely evaluate the advantages of new material. 2010;19(5):364-8. J Appl Polym Sci. Adding denture cleanser to microwave disinfection regimen to reduce the irradiation time and the exposure of dentures to high temperatures.