Effect of microwave disinfection on mechanical properties of denture base acrylic resin

Effect of disinfection techniques on physical-mechanical properties of a microwave-activated acrylic resin

“…In the present study, the Knoop hardness significantly increased after microwave polymerization, as did the Izod impact strength and glass transition temperature. Others suggested that the protocol (720 W/5 minutes) reduced [20] or did not affect (650 W/3 and 5 minutes) the impact strength [19,23] . A protocol of 650 W/3 minutes decreased the glass transition temperature of acrylic resin [21] .…”

“…Different time (3, 5, and 6 minutes) and power (650 and 720 W) settings of microwave irradiation have been proposed in the literature for denture disinfection [10,[19][20][21][22] . Despite its effectiveness in disinfection, these protocols have reached contradictory findings, including deleterious effects on some physical and mechanical properties due to the material heating during the irradiation, which could affect the polymer structure [19][20][21] . Previous studies suggested that the time the acrylic resins are subjected to heat during disinfection could be reduced in order to produce adequate disinfection without any adverse effects [7,23,24] .…”

Cell Membrane Integrity of Candida Albicans after Different Protocols of Microwave Irradiation

“…Destruction of microorganisms by the non-thermal effect could be explained by absorption of micro wave irradiat ion by certain biochemical molecu les, such as proteins and nucleic acids. So, the interaction between electro magnetic field produced by the microwaves and the cell mo lecules would lead to cell destruction [47]. It is also suggested that one of the antifungal effect with microwaves is due to the fact that the temperature rise in the microorganis m is greater than that of the surrounding mediu m. In addition, the microorganisms themselves have thermal p roperties, which are d irect ly involved with microbial destruction [16].…”

“…In addition, it has been suggested that micro waves are not sufficiently strongto directly change chemical bonds and their effects have been attributed to other mechanis ms such as dielectric relaxation, ionic conductivity and biopolymer alterat ion [7]. However, micro wave heating is energy conversion and not heating as in a conventional oven, sothe micro wave absorbent material exposed to a microwave field converts this energy into heat within itself [47]. In this context, Senna et al [48] reported that microwave irrad iation reaches the microorganis m killing temperature more effect ively than conventional heating process, which needs to heat the entire environ ment.…”

Proteti̇k Di̇ş Tedavi̇si̇nde Dezenfeksi̇yon Ve Steri̇li̇zasyon

“…Ancak yapılan bir çalıĢmada mikrodalga ile 5 dk dezenfeksiyonun ısı ile polimerize akrilik rezinlerin fiziksel özelliklerini zayıflattığı bildirilmiĢtir. 59 Astarlama yapılmıĢ ve yapılmamıĢ akrilik protez kaide materyalleri üzerinde sodyum hipoklorit ve mikrodalga ile dezenfeksiyonun etkilerinin araĢtırıldığı bir çalıĢmada sodyum hipoklorit ile dezenfeksiyonun fiziksel özellikler dikkate alındığında daha güvenli bir yöntem olduğu, mikrodalga ile dezenfeksiyon sonucunda kaidelerde bir miktar büzülme olduğu gösterilmiĢtir. 26 Kullanılan dezenfeksiyon yöntemlerinin materyalin yapısal özellikleri üzerindeki etkisi kadar kaide materyali, astar materyali ve protez diĢlerinin renk stabilitesi üzerine etkisi olabileceği de dikkate alınmalıdır.…”