Evaluation of Three Hard Relining Materials in Complete Dentures
Condition: Complete Mandibular Dentures With Poor Retention
Study type: Interventional

Summary: 
      Purpose: The purpose of this study is to evaluate three hard relining materials after 3 and 6
      months of use with mandibular complete dentures. The effect of hard relining materials on
      supporting tissues and patients' satisfaction will also be assessed.

      Materials and Methods: 36 complete edentulous patients who already have maxillary dentures
      and complaining of instable mandibular dentures will be invited to participate in this study.
      Mandibular dentures will be relined randomly by one of three relining materials: two
      chairside relining materials (Tokuyama Rebase II Fast, Tokuyama Dental Co, Japan), and
      (Flexacryl Hard, Lang Co, USA) and one heat cured acrylic resin (Vertex, Dental technology
      Co, Holland).

      The color stability of relining material, peeling, and the effect on supporting tissue will
      be assessed by two separate prosthodontists after 3 and 6 months of follow up. In addition,
      patients will be asked to grade there overall satisfaction on a Visual Analogue Scale (VAS)
      ranging from 0 to 100.
    

Detailed description: 
      Relining denture is a process of resurfacing the tissue side of a denture to make it fit more
      accurately Direct relining of removable dentures with hard chair-side reline materials is
      suitable for improving the fit of the denture bases to the supporting tissues. Chairside
      reline materials are more convenient than those processed in a laboratory because the direct
      method is faster and does not cause clinically significant dimensional changes of the reline
      resin. However, when autopolymerized reline resins are used with a direct method, several
      problems can occur as burning sensation caused by monomers, an exothermic heat reaction and
      an unpleasant odor.

      There are three types of hard relining chair-side materials: Dual-polymerized Visible
      light-polymerized as Triad DuaLine, Light Liner (Hard), Astron LC (Hard).Visible
      light-polymerized as Lightdon-U, Triad Hi-Flow Reline Material, Triad VLC Reline Material.
      Finally, autopolymerized as New Truline, Tokuyama Rebase II (Fast) , GC Reline. Other
      concerns related to direct reline materials include patient tolerance (taste, temperature,
      odor), color stability, durability and ease of handling and polishing.

      Few studies evaluated the effect of disinfection solutions on relining materials properties
      as roughness and hardness. In one study, disinfectant solutions caused a decrease in
      hardness, whereas with roughness, the materials tested showed a statistically significant
      increase, except for Tokuyama. Depending on the examined relining materials, some materials
      have increased and the others have decreased surface roughness after immersion in
      disinfecting solutions or microwave disinfection.

      All previous laboratory studies concentrated on the effects of disinfection on relining
      materials properties as roughness, hardness, color change. However, the clinical studies did
      not compare chemically cured and heat cured relining materials and their effects on
      supporting tissue. The aim of this study is to evaluate the clinical performance of two
      -chemically cured- and heat cured denture relining material after 3 and 6 months of use. In
      addition, the effect of hard relining materials on supporting tissues, and patients'
      satisfaction has not been evaluated yet.
    

Intervention name(s): Rebase II Fast; Flexacryl; Vertex
Intervention type(s): Other; Other; Other
Intervention description(s): It is going to be used a direct relining material; This is going to be used as a second direct relining material; This is going to be used as an indirect relining material
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Chair-side hard relining; complete denture; patients' satisfaction; supporting tissues; autopolymerized reline resins; heat cured relining material