When patients move from natural teeth to complete dentures, implant-supported restorations or another definitive prosthesis, interim dentures and immediate dentures can both provide temporary tooth replacement. However, the terms describe different aspects of treatment.
An interim denture is intended for temporary use during a transitional stage. An immediate denture is fabricated before the planned teeth are extracted and inserted immediately after extraction. This difference affects impression timing, laboratory planning, post-extraction adjustment and patient expectations.
For dental technicians, the workflow extends from working-cast preparation to processed acrylic denture trimming. Different HP burs can be used with the same straight handpiece at different stages.
What Is an Interim Denture?
An interim denture is used for a limited period before definitive rehabilitation. It may support aesthetics and function during staged extractions, implant healing or tissue stabilization.
Interim dentures as temporary removable prostheses used between initial treatment and a definitive restoration. Because the oral condition may continue to change, an interim denture may require adjustment, relining or replacement as treatment progresses.
What Is an Immediate Denture?
An immediate denture is constructed before extraction and inserted on the same day the designated teeth are removed. This avoids an obvious edentulous period and preserves useful pre-extraction information such as tooth position and appearance.
The challenge is that the laboratory must fabricate the denture before the final post-extraction tissues exist. The technician therefore works from pre-extraction records and modifies the cast according to the treatment plan.
A 2025 systematic review of immediate complete dentures emphasized defined clinical protocols, minimally invasive surgical procedures, attention to occlusion and regular patient follow-up.
Interim vs Immediate Dentures: What Is the Difference?
| Feature | Interim Denture | Immediate Denture |
|---|---|---|
| Definition | Temporary prosthesis during a treatment phase | Denture inserted immediately after extraction |
| Timing | Depends on treatment plan | Same day as extraction |
| Records | May be taken at different stages | Primarily pre-extraction |
| Main role | Transitional function and aesthetics | Immediate tooth replacement |
| Main challenge | Adapting to treatment changes | Predicting post-extraction anatomy |
| Follow-up | Adjustment as treatment progresses | Early adjustment and management of ridge remodeling |
An immediate denture can also function as an interim prosthesis when it is intended only for the healing period. Immediate describes when it is inserted; interim describes its role in the treatment plan.
Why Does an Immediate Denture Become Loose?
After extraction, the alveolar ridge changes in width and height as healing occurs.
A systematic review and meta-analysis found mean horizontal ridge reduction of approximately 2.73 mm at clinically measured non-molar sites and 3.61 mm at radiographically measured molar sites, although the amount varies according to location and measurement method.
As the ridge remodels, an immediate denture that initially adapts well may become less retentive. Follow-up can therefore involve pressure-area adjustment, occlusal adjustment, relining, rebasing or replacement.
Laboratory Workflow: One Model S100, Different HP Burs
The Kaneiko Model S100 Straight Low-Speed Dental Handpiece can serve as the handpiece platform across several stages of denture laboratory work.
It uses a 1:1 direct-drive transmission, accepts Ø2.35 mm HP burs and operates at up to 40,000 rpm, depending on the connected air motor. Model S100 is the non-fibre-optic version, making it suitable for extraoral laboratory procedures where external laboratory lighting is available.
Instead of changing handpieces, the technician can keep the Model S100 and select a compatible HP bur according to the material and task.
Step 1: Working Cast Preparation — Model S100 + Plaster Bur
After the impression is poured, the working cast is inspected for excess gypsum and irregularities.
The Kaneiko Model S100 can be paired with the Mr.Bur CVD Coated Cross Cut Standard Tungsten Carbide Bur for Plaster.
Mr.Bur specifies this bur for HP straight handpiece low-speed use, including denture technique and plaster applications. The original denture workflow uses it to refine gypsum models before wax-up and articulation.
The objective is controlled cast refinement so the model provides a reliable foundation for subsequent tooth arrangement and denture fabrication.
Step 2: Immediate Denture Cast Modification — Model S100 + Medium Cross Cut Laboratory Bur
Immediate dentures add another laboratory challenge because the remaining teeth are still present when the records are obtained.
The cast may therefore need modification to simulate the planned extraction areas before the replacement teeth are arranged.
Using the same Kaneiko Model S100, the technician can change to the Mr.Bur Tungsten Carbide Medium Cross Cut Laboratory Bur.
Mr.Bur identifies this as an HP straight-handpiece, low-speed bur for denture technique. In the original immediate-denture workflow, the bur is used during cast refinement and simulation of extraction sites before articulation and processing.
The principle is simple: the handpiece remains the same, while the bur changes according to the laboratory task.
Step 3: Acrylic Denture Trimming — Model S100 + Acrylic Resin Bur
After tooth arrangement, wax-up, flasking and processing, the denture is deflasked. Excess acrylic resin and processing flash may then require removal.
The Kaneiko Model S100 can now be paired with the Mr.Bur Cross Cut Standard Tungsten Carbide Bur for Acrylic Resin.
Mr.Bur specifies this bur for HP straight handpiece low-speed use, including prosthodontics, denture technique and acrylic denture applications. The original article uses it during deflasking and initial trimming to remove excess acrylic and shape the denture base.
This pairing can support acrylic denture trimming, border reduction, flange contouring and refinement of bulky areas before polishing. Operating speed and technique should always follow the bur, material and handpiece manufacturer's instructions.
The laboratory workflow is therefore:
Model S100 + Plaster Bur → Working Cast Preparation → Model S100 + Medium Cross Cut Laboratory Bur → Immediate Denture Cast Modification → Model S100 + Acrylic Resin Bur → Processed Denture Trimming
Why Trimming Is Not the Final Step
Carbide bur trimming creates the required contour, but it does not create the final polished denture surface.
Research on denture-base acrylic found that specimens finished with tungsten carbide burs had greater surface roughness than specimens subsequently polished using appropriate polishing procedures. The same research notes that rough denture-base surfaces can encourage microorganism adhesion and plaque formation.
The practical sequence should therefore progress from trimming → contour refinement → finishing → polishing.
The carbide burs in this workflow perform material reduction and shaping; final polishing remains a separate laboratory stage.
Clinical Follow-Up After Immediate Denture Placement
Insertion is only the beginning of the immediate denture procedure.
Follow-up should reassess pressure areas, extraction-site healing, denture borders, retention, stability, vertical dimension and occlusal contacts.
The 2025 systematic review of immediate complete dentures also emphasized regular patient follow-up and maintenance of vertical dimension and balanced occlusion.
Patients should therefore understand from the beginning that denture fit may change during healing and that relining or replacement may eventually become necessary.
Do Digital Dentures Eliminate These Adjustments?
No. Digital denture workflows can reduce treatment time, but they do not eliminate clinical verification or denture adjustment.
A systematic review found that digital complete-denture workflows saved approximately 205 to 233 minutes of clinical time compared with conventional methods in included studies. However, additional visits, retention problems and denture remakes were still reported.
Whether a denture is conventionally processed, milled or 3D printed, fit evaluation, laboratory refinement and follow-up remain important.
Frequently Asked Questions
Are interim and immediate dentures the same?
No. Interim dentures are defined by their temporary treatment role, while immediate dentures are defined by insertion immediately after extraction. An immediate denture can also serve as an interim prosthesis.
Which burs are used in this denture workflow?
The workflow uses the Mr.Bur CVD Coated Cross Cut Standard Tungsten Carbide Bur for Plaster for working-cast preparation, the Mr.Bur Tungsten Carbide Medium Cross Cut Laboratory Bur for immediate-denture cast modification, and the Mr.Bur Cross Cut Standard Tungsten Carbide Bur for Acrylic Resin for processed acrylic trimming.
Why does an immediate denture need relining?
Post-extraction bone and soft tissues remodel, changing the supporting ridge and reducing adaptation between the denture base and underlying tissues.
Key Takeaway
Understanding interim vs immediate dentures requires both clinical and laboratory perspectives. Interim dentures serve a temporary treatment phase, while immediate dentures are defined by placement directly after extraction.
In the laboratory, the Kaneiko Model S100 Straight Low-Speed Dental Handpiece can remain the central straight handpiece while the technician changes the HP bur according to the material: the plaster bur for working-cast refinement, the medium cross cut laboratory bur for immediate-denture cast modification, and the acrylic resin bur for processed denture trimming.
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