FREQUENTLY ASKED QUESTIONS
FOR DENTAL LABORATORIES
- What is WELDENZ Dental Resin?
WELDENZ is a uniquely formulated high-performance, thermoplastic resin comprised primarily of copolymer polypropylene. It is an innovative, easy-to-use biocompatible resin that simplifies dental prosthesis fabrication and patient treatment.
- What are the indications for WELDENZ crowns and bridges?
Because WELDENZ is a thin yet strong resin, its removable ‘capping’ feature is perfect for bridges and crowns while preserving the natural structure of adjacent, supporting teeth. It is non-invasive and in most cases, requires very little or even no preparation of teeth.This makes WELDENZ an outstanding alternative for cases characterized by high bone resorption or when an implant is too costly for the patient.
- Can I add stain to WELDENZ Dental Resin to characterize the restoration?
Fiber can be added to characterize the restoration.
- What is the life expectancy of a WELDENZ crown/ bridge/ denture?
A WELDENZ appliance lasts up to 2-3 years depending on the patient. With the use of pontic teeth combined with WELDENZ pink resin base, it can last longer than 3 years. A regular visit to the dental clinic for cleaning and polishing is recommended.
- How long can the pontic span be without additional reinforcements?
There is no limit to the pontic span as the WELDENZ base plate is able to support the teeth. However, shrinkage might happen as pontic span increase. In this case, the patient will feel uncomfortable due to the tightness of the prosthesis.
- How do I repair WELDENZ dental prosthesis if something should break or if I want to add a tooth?
WELDENZ Dental Resin of the same shade can weld together as long as both resin are polymerized the same number of times. Therefore, WELDENZ can be repaired or a tooth can be added as long as the resin used for repair/replacement is polymerized the same number of times.
- What is the advantage of using WELDENZ Dental Resin over lab processed, pressure-cured acrylic?
Acrylic denture, especially when it involves metal reinforcement, takes a long time to fabricate. WELDENZ denture, on the other hand, is easy to fabricate and polish. Therefore, it takes a shorter time than conventional method of fabrication. Compared to acrylic denture, WELDENZ denture is more comfortable, and safer as WELDENZ has no allergic factor.
- Can I use metal or reinforced fiber reinforcements with WELDENZ processed bridges?
It is possible to use such reinforcement but WELDENZ does not need that.
- How many shades are available for WELDENZ crowns and bridges?
There are three shades for the teeth – Bright White (T1), Standard White (T2) and White (T3).
- How many shades are available for WELDENZ denture bases?
There are three shades for the denture base – Light Pink (G1), Standard Pink (G2) and Dark Pink (G3).
- Is any curing required for a WELDENZ denture?
No curing is required. The main component of WELDENZ dental resin is Copolymer Polypropylene which its characteristic property is to become soft when it warms up and hard when it cools down. If the clasp of WELDENZ denture loosens, you can tighten it by soaking it in warm water for at least a minute and holding the clasp tightly.
- For removable crown, will patients swallow the crown accidentally?
WELDENZ’s thin yet firm material means that the crown/bridge fits snugly. We have not heard of any cases of patients swallowing a crown accidentally.
- What is the approximate amount of resin for each tooth (crown & bridge application)?
About 5-10 grams is needed to make a crown and 10-13 gram is needed for a bridge.
- Is there any difference between making a WELDENZ denture and other flexible dentures?
The fabrication process is the same as other flexible partials that are using the injection method.
- What is the minimal thickness for a WELDENZ abutment tooth or clasp?
The minimum thickness for the abutment tooth or clasp is 0.5mm.
- What is the minimal thickness for a WELDENZ appliance that fits over the natural tooth?
The minimum thickness for a WELDENZ appliance that fits over the natural tooth is 1.0 – 1.5mm. However, the thickness is varied depending on the design of each denture.
- How strong is the WELDENZ Dental Resin (modulus of elasticity, flexural strength, fracture toughness, etc)?
Material Acrylic Polysulphone PET Weldenz Strength (MPa) 55~76 70~100 48~73 65~130 Modulus of Elasticity (MPa) 2400~3100 2200~2600 2800~4800 2400~6000 Bending Strength (MPa) 86~118 90~106 96~113 90~200 Coefficient of Water Absorption (W%) 0.4 0.03 0.05 <0.01
- What is the maximum pontic span for a bridge with 2 abutments in the anterior/posterior?
There is no limit to the pontic span. However, there will be shrinkage when the pontic span increase. This shrinkage might make the patient feel uncomfortable (tightness).
- Can I use WELDENZ Dental Resin for partial dentures? If so, will I need a metal framework?
Yes, WELDENZ Dental Resin can be used for partials. Depending on individual patient’s preference, WELDENZ partial could be made with metal framework.
- Are WELDENZ dentures flexible?
WELDENZ dentures can be flexible.
- Can I add a tooth or repair a WELDENZ partial?
Yes, it is possible to repair, reline and rebase a WELDENZ prosthesis. The resin used for repair must be of the same shade and has been polymerized the same number of time as the denture to be repaired.
- Are WELDENZ dentures recommended for bruxers or clenchers?
Yes, WELDENZ can be recommended for bruxers or clenchers. As WELDENZ is less abrasive, it is beneficial for bruxers or clenchers since it will not damage their natural teeth. A regular visit to the dental clinic for cleaning and polishing is recommended.
- Is WELDENZ flexible (what is the modulus of elasticity?)?
Yes, WELDENZ is flexible. The modulus elasticity is 2400~6000 MPa.
- Can I use WELDENZ Dental Resin for posterior bridges?
WELDENZ can be used for both anterior and posterior bridges.
- Will WELDENZ dentures discolour over time?
WELDENZ dentures will not discolour over time. However, over time, the surface may become rough as it is non-abrasive. This may cause stains to appear on the surfaces of the teeth. A trip to the dentist to polish the teeth will remove the stain. To eradicate that, we recommend applying composite resin on the surface of the teeth to make it more durable and stain-resistant. It will enhance the aesthetic of the teeth too.
- Does the dentist need to prepare undercuts in the natural dentition for retention of the WELDENZ appliance?
WELDENZ material is thin and flexible. In most cases, no undercut is needed.
- Can I construct a WELDENZ appliance across all occlusal surfaces to open the bite?
Yes, WELDENZ can be constructed across all occlusal surfaces. However, in some cases, the material might shrink a little causing some discomfort to the patient. Hence, we would recommend the construction of two posterior and an anterior bridge to achieve the same purpose.
- If we make mistake and mill too much or if dentures shrink as time goes by, is it possible to rebase and reline the dentures? If yes, how do you do that?
Yes, it is possible to repair, reline and rebase WELDENZ dentures. The same shade of resin that has been polymerized the same number of times can be welded together. Please refer to our Tutorial Videos and Quick Guides.
- What equipment do we need to start using WELDENZ?
If your lab currently has the injection system for fabricating flexible partials, it can be used for WELDENZ too. For fabricating WELDENZ, the optimal injection pressure is approximately 0.7 MPa. The WELDENZ starter kit includes the furnace, manual press, melting cylinder and injection flask.
- Can we use our current injection system?
WELDENZ works with most existing injection systems used for fabricating flexible partials.