Potential Therapeutic and Effective Properties of Soft Tissue Liners

Soft tissue liners are polymer materials between the oral tissue and the surface of the denture. They have an essential role in reducing the effect of the masticatory force on the oral mucosa. This short review gleaned data on soft tissue liners to highlight their potential therapeutic importance in the management of denture-related stomatitis and their comparison to other materials. Published articles in many databases were collected using keywords with soft liner properties, viscoelastic, dental materials, impression technique, and additive liner materials. The soft liners were compared to the viscoelastic oral mucosa, and their influences on the control of denture plaque were highlighted too. Their application in the treatment of denture-related stomatitis, as well as adhesion and biofilm formation, was highlighted. The result showed that soft tissue liners have high therapeutic efficacy and effective properties in treating denture stomatitis due to the incorporation of chlorhexidine, antifungal, and antimicrobial agents. The use of soft liners improved ridge resorption and had a crucial effect on the loss of denture fit and stability. In addition, soft tissue liners in combination with additive materials recovered the effect of saliva on the formation and adhesion of biofilm. Uniquely, the application of soft liners in the functional impression technique was ideal, due to their extensive physical properties, their viscoelasticity, and the immediate poured impression. Therefore, soft liners are highly recommended in many dental conditions such as dentures opposing natural dentition, resorption of irregular bone, immediate implant placement, tooth undercuts, oral mucosa atrophy, bruxism, and xerostomia

Structure And Dynamics Of Modulated Traveling Waves In Cellular Flames

We describe spatial and temporal patterns in cylindrical premixed flames in the cellular regime, $Le < 1$, where the Lewis number $Le$ is the ratio of thermal to mass diffusivity of a deficient component of the combustible mixture. A transition from stationary, axisymmetric flames to stationary cellular flames is predicted analytically if $Le$ is decreased below a critical value. We present the results of numerical computations to show that as $Le$ is further decreased traveling waves (TWs) along the flame front arise via an infinite-period bifurcation which breaks the reflection symmetry of the cellular array. Upon further decreasing $Le$ different kinds of periodically modulated traveling waves (MTWs) as well as a branch of quasiperiodically modulated traveling waves (QPMTWs) arise. These transitions are accompanied by the development of different spatial and temporal symmetries including period doublings and period halvings. We also observe the apparently chaotic temporal behavior of a disordered cellular pattern involving creation and annihilation of cells. We analytically describe the stability of the TW solution near its onset+ using suitable phase-amplitude equations. Within this framework one of the MTW's can be identified as a localized wave traveling through an underlying stationary, spatially periodic structure. We study the Eckhaus instability of the TW and find that in general they are unstable at onset in infinite systems. They can, however, become stable for larger amplitudes.Comment: to appear in Physica D 28 pages (LaTeX), 11 figures (2MB postscript file