Why You Need a Temporary Crown After a Root Canal
After a root canal, the tooth is structurally weakened and needs immediate protection. A temporary crown serves as a short-term restoration while the permanent crown is being fabricated. Our our methodology ensures all health information is accurate and evidence-based. This article explains why a temporary crown after a root canal is essential, how it is made, how long it lasts, and what it costs in Australia.
Why Does a Root Canal Leave the Tooth Fragile?
After root canal therapy, the tooth loses a significant amount of moisture. Research by Sedgley and Messer (1992, Journal of Endodontics) found that dentin water content drops by approximately 20%, leaving the remaining structure brittle and prone to microcracks. The creation of an access cavity during how a root canal is performed removes the roof of the pulp chamber and additional dentin, further weakening the tooth.
The landmark study by Aquilino and Caplan (2002, Journal of Endodontics) demonstrated that unrestored posterior root canal-treated teeth have a fracture risk 5-6 times higher than those crowned. The 10-year survival rate for teeth with a crown is 85-90%, compared with only 50-60% without a crown. The Australian Society of Endodontology (ASE) issued a position statement in 2021 recommending that all root canal-treated posterior teeth receive a full-coverage crown restoration within 4 weeks to prevent fracture.
In Australia, the Australian Institute of Health and Welfare (AIHW) reported that 1.2 million root canal procedures were performed in 2020-21, making this a very common scenario. The temporary crown is the first step in protecting this fragile tooth while the permanent restoration is being made.
What Is a Temporary Crown and What Does It Do?
A temporary crown after a root canal is a short-term, custom-fitted cap placed over the treated tooth while the permanent crown is being fabricated in a dental laboratory. It is typically worn for 2-4 weeks. The three main materials used are tooth-coloured acrylic (polymethyl methacrylate), bis-acryl composite (brands such as Luxatemp and Protemp 4), and preformed stainless steel crowns for posterior teeth.
Acrylic has approximately 7% polymerisation shrinkage, while bis-acryl shrinks only 2-3%. The flexural strength of bis-acryl is around 80-100 MPa, and its fracture resistance is approximately 400-500 N, compared with 200-300 N for acrylic. The Australian Dental Association (ADA) Policy 6.1.6 (2020) states that a provisional restoration must protect the tooth, maintain occlusal function, prevent gingival overgrowth, and allow proper oral hygiene.
It is important to distinguish the temporary crown from the temporary filling (Cavit G, IRM, or Coltosol) placed immediately after root canal treatment. The temporary filling is not designed to withstand occlusal forces and can fracture or leak if used as a long-term restoration. The temporary crown also maintains the space between teeth, prevents opposing teeth from drifting, and protects the gingival margin while the permanent crown is being made. On an itemised treatment plan, the temporary crown is listed under ADA item number 615 (acrylic/composite) or 616 (stainless steel).
How Is a Temporary Crown Made and Fitted?
The process begins with the dentist removing the temporary filling using a round bur (#4 or #6) at high speed with water spray. The tooth is then confirmed to be comfortable before starting the preparation. The tooth is prepared with diamond burs: occlusal reduction of 1.5-2.0 mm and axial reduction of 1.0-1.5 mm, while preserving a ferrule of 1.5-2.0 mm of vertical sound tooth structure above the gingival margin. A lack of ferrule increases failure rates by up to 30% (Sorensen & Engelman, 1990).
An impression is taken with polyvinyl siloxane or a digital scan and sent to the laboratory for the permanent crown. The temporary crown is fabricated chairside in 15-30 minutes from either self-curing acrylic (e.g., Duralay) or dual-cured bis-acryl composite. It is then trimmed with diamond burs and polished with silicone polishers. The temporary crown is cemented with temporary cement such as TempBond (zinc oxide-eugenol), RelyX Temp NE (non-eugenol), or GC TempCem, applied in a film thickness of just 15-25 μm. The occlusion is checked with articulating paper (e.g., Bausch 40 μm).
There are trade-offs between the different materials. Chairside acrylic is cheaper but has more shrinkage and porosity. Bis-acryl costs about $15-20 more per unit but fits better and is stronger. Laboratory heat-cured acrylic offers the best fit and strength but costs $200-400 and requires a second appointment. Your dentist will choose the option that best suits ythis resourceal situation and budget.
How Long Do You Need to Wear a Temporary Crown?
The typical timeframe is 2-4 weeks, which is how long the dental laboratory needs to fabricate the permanent crown. According to Balkenhol et al. (2008, Journal of Dentistry), temporary crowns survive an average of 4.2 weeks for acrylic and 5.8 weeks for bis-acryl. Failure statistics show dislodgement rates of 2-5% and fracture rates of 1-3% for acrylic versus 0.5-1% for bis-acryl between appointments (Christensen, 2002).
After 4 weeks, the risk of cement washout, marginal leakage, and bacterial recontamination rises above 20%, which is why delaying the permanent crown is risky. The dental laboratory fabricates the permanent crown after a root canal during this time.
To protect the temporary crown, chew on the opposite side of your mouth, avoid sticky foods such as caramel and chewing gum, and avoid hard foods like nuts and crusty bread. A what to eat after a root canal diet helps avoid putting pressure on the temporary crown. If the temporary crown falls off, keep it and contact your dental practice immediately. Never attempt to re-cement it with superglue or over-the-counter denture adhesive, as this can damage the underlying tooth structure.
How Much Does a Temporary Crown Cost in Australia?
According to the Australian Dental Association (ADA) fee survey from 2019, the average fee for an acrylic or composite temporary crown (item 615) is approximately $210, with a typical range of $150-$350. Stainless steel temporary crowns (item 616) range from $120 to $250. By comparison, permanent crown costs in Australia are significantly higher: ceramic crowns $1,200-$2,200, metal-ceramic crowns $1,000-$1,800, and full gold crowns $1,500-$2,500. The temporary crown is a minor component of the overall restoration cost.
Private health fund rebates for a temporary crown are modest, typically $50-$120 depending on the fund and annual limits. Medicare does not cover temporary crowns except under the limited Chronic Disease Dental Scheme. The Child Dental Benefits Schedule (CDBS) excludes temporary crowns entirely, covering only basic restorative items (511-525) up to a maximum benefit of $1,026 over two years. The temporary crown fee is usually billed separately from the root canal treatment fee, so you can find a breakdown of root canal costs in Australia in our dedicated guide. Always request a written treatment plan with item numbers.
Frequently Asked Questions
Can I eat normally with a temporary crown after a root canal?
You can eat, but you will need to be careful for the 2-4 weeks the temporary crown is in place. Chew on the opposite side of your mouth and avoid sticky foods such as caramel and chewing gum, as well as hard foods like nuts and crusty bread that could dislodge or fracture the crown. The temporary cement is designed to hold the crown securely but not permanently, so treating the area gently is essential.
What should I do if my temporary crown falls off?
Keep the crown and contact your dental practice as soon as possible - dislodgement occurs in roughly 2-5% of temporary crowns between appointments. Do not attempt to re-cement it yourself with superglue or over-the-counter denture adhesive, as this can damage the underlying tooth structure or make it difficult for the dentist to re-cement it properly. Most practices will re-cement the crown quickly, often at minimal or no additional cost.
Why can't I just keep the temporary filling instead of getting a temporary crown after a root canal?
A temporary filling such as Cavit G or IRM is placed immediately after the root canal to seal the access cavity, but it is not designed to withstand the forces of chewing. A temporary crown covers the entire tooth, protecting the weakened structure from cracks and fractures while preventing bacteria from leaking into the canal system. Unrestored posterior root canal-treated teeth fracture 5-6 times more often than crowned teeth, which is why the Australian Society of Endodontology recommends crowning within 4 weeks.
Is getting a temporary crown painful?
No - because the tooth has already had the nerve removed during root canal treatment, it is non-vital and does not feel sharp pain during crown preparation. You may experience some pressure or gum sensitivity from the tooth preparation and impression-taking, but this typically settles within a few days. Over-the-counter pain relief such as paracetamol or ibuprofen is usually sufficient if needed.
How long can I delay getting the permanent crown?
The Australian Society of Endodontology recommends restoring root canal-treated posterior teeth with a full-coverage crown within 4 weeks. After this point, the risk of cement washout, marginal leakage and bacterial recontamination rises above 20% (Balkenhol et al., 2008). Delaying beyond 8 weeks significantly increases the chance of the temporary crown fracturing or the treated tooth cracking, which could ultimately lead to endodontic retreatment.
For more information on root canal treatment and aftercare, explore our endodontics guides.
