Denture Lining Material PDF

## Denture Lining Material ### Biomaterial * **Definition:** They are very soft material that added to fitting the surface of denture to act as cushion * **Types:** * Tissue Conditioner * Soft Liners (acrylic / rubber) ### Tissue Conditioner * **Definition:** Resilient liner act as temp...

## Denture Lining Material ### Biomaterial * **Definition:** They are very soft material that added to fitting the surface of denture to act as cushion * **Types:** * Tissue Conditioner * Soft Liners (acrylic / rubber) ### Tissue Conditioner * **Definition:** Resilient liner act as temporary cushion to prevent masticatory loads from being transferred to underlying tissue. * **Uses:** * After surgery (reduce pain – surgical pack) * Functional Impression * Treatment of irritated denture-bearing mucosa * **Composition:** * **Powder:** Ethyl methacrylate polymer (no initiator) * **Liquid:** Aromatic ester, ethyl alcohol & Butyl Phthalate (plasticizer). It is a solvent liquid, not a monomer. * **Reaction:** * Gelation Reaction (physical reaction) * As solvent evaporates, polymer gel is left behind. * **Manipulation:** * Mouth-cured or chair side technique * **Properties:** * Hardness is very low (softest of resilient liners) * Flowable & gets excellent details * No reaction with tissue (good biological effect) * Weight loss (evaporation of solvent) * Material loses resiliency after 5 days due to losing plasticizer. * Dimension change is less than 2%. **Material must be replaced.** **Kit of this material contains Lubricants to paint the polished surface of denture for easy removal of excess material.** ### Soft Liners * **Uses:** * Knife-edge ridge covered by thin mucosa * Mucosa very thin (inadequate thickness) * Patient who has bruxism or clenches his teeth * Denture patient problem is psychological (not tolerant to hard denture) * **Requirements:** * **Resilient:** * Dimension stable * Adhere to denture base * Good rupture properties * **Color stability:** * Compatible with tissue * Easy in processing * Low water absorption ### Classification | | Acrylic | Cold Cure | Rubber | |-------------|-------------|------------|--------| | **Cold Cure** | Plasticized | Dold Cure | Heat Cure | | **Temporary** | One month | Permanent | Permanent | | | (6-7 Months) | (6-7 Months) | (6-7 Months) | | **Permanent** | P/L | Paste (silicone) | Single paste | | | Chair side | Catalyst (liquid) | (vinyl terminated silicon polymer) | | | Lab | Lab | Lab | | **Replaced due to**: | Plasticizer | Water sorption & | | | | | fungal growth | | **Note:** * All soft liners are permanent to the patient, but change after time * **Temporary:** A few weeks to a month * **Permanent:** 6-7 months ### Recent Advances #### A - Temporary Soft Liner * **Acrylic cold cure - mouth cure (not used)** * Manipulation: Similar to conditioner (chair side technique) * **Indication:** * Patient problem denture * Patient with severe undercuts * Improve old dentures * Follow up to tissue conditioner * **Composition:** * **Pink Powder:** * PMMA * MMA * Initiator * Tertiary amine * **Liquid:** * Plasticizer (aromatic ester) * Ethanol * **Reaction:** Chemical Polymerization Reaction * **Properties:** * Loose resiliency after one month * Poor adhesion to denture * Cracks on surface * Not easy to clean. * Bad Biological Effect * Tertiary amine & monomer cause irritation * Fungal growth & bad odor * **Cleaning:** * Best way for cleaning is using very diluted solution of hypochlorite to avoid damaging the soft liner. * Avoid oxygenation cleaners that may cause degradation and pitting of the material. #### B - Permanent Soft Liner * **Laboratory Processed (used now)** * Types * Heat Cure Acrylic that is called Plasticized acrylic resin * Cold cured (Room Temperature Vulcanization – RTV) * Heat cured (Heat Temp Vulcanization - HTV) * Rubber (silicon) * **Cold Cure:** * Difficult manipulation (flasking-packing as denture) * **Heat Cure:** * Difficult manipulation (flasking-packing as denture) **Biological Properties:** * Fungal & bacterial growth * In some patients, these materials can degrade rapidly, causing bad odor and irritation. #### Light Activated Type * **Single paste in opaque plastic cartridge of:** * Urethane di-methylacrylate * Filler * Micro fine silica * **Used up to 1 year meaning a Permanent Soft Liner ** * **Bonding agent used before placing in denture.** * **Visible light cured allowing relining completed in 30-45 minutes.** * **Chair Side** #### Recent Advancements * **To improve antimicrobial and antifungal properties ** * **Act as a mechanical barrier to decrease water sorption.** * **Solubility of chemical components.** * **To create roughness of the fitting surface of the denture.** * **To improve tensile bond between denture, soft liner** * **It acts as a permanent soft liner as no plasticizer leaching out** * **Low surface tension and good wetting and bond with the denture.** * **Resistance to fungal growth.** * **It heat-cured silicone permanent lining with no plasticizer.** * **Biocompatible** * **Strongly bond to any denture base (old or new).** * **It cold-cured silicone permanent lining.** * **Biocompatible.** * **Bond well to the denture.** * **Direct applied from the cartridge onto the denture (chair side use).**