A broken smile isn't only a dental issue. It changes how you eat and how confident you feel day to day. This case follows a patient who came to ArtSmiles after his All on X acrylic bridge fractured about two years after it was fitted by another clinician. We rebuilt the bridge in multilayer zirconia on his existing implants, with a reinforcing titanium bar underneath.
In this article
The Problem: A Fractured Acrylic Bridge
This patient had previously received an All on X implant supported restoration from another clinician. While the concept behind the original treatment was sound, the acrylic bridge had fractured after 2 years in function.
Acrylic prosthesis fracture is actually one of the most commonly reported complications in implant supported full arch restorations. A retrospective study by Mackert et al. (2024) found that catastrophic fracture of the acrylic resin accounted for 61% of prosthesis replacements, with a combined survival rate of just 54% at five years and 32% at ten years. Similarly, a systematic review by Patzelt et al. (2014) identified acrylic prosthesis fracture as the major prosthetic complication in the All on 4 treatment concept.
Clinical Examination: Healthy Implants, Reduced Vertical Dimension
We performed a thorough clinical examination. The good news was that all of the existing implants were healthy and well integrated. There were no signs of peri-implant disease or implant failure, which meant we could work with the existing foundation.
However, the examination revealed that the vertical dimension of occlusion (VDO) had been reduced. This is the measurement of the height relationship between the upper and lower jaws when the teeth are in contact. When the vertical dimension is too low, the acrylic layer of the prosthesis becomes very thin, making it far more vulnerable to fracture under normal biting forces.
As Gittelson (2002) highlighted, getting the vertical dimension right is one of the main factors in how long full arch implant supported prostheses actually last. In this case, the reduced VDO was a key contributing factor to the original bridge failure.
The Treatment Plan: From Temporaries to Zirconia
Rather than rushing straight to a final restoration, we recommended a staged approach. The plan involved creating temporary bridges first to carefully establish the ideal aesthetics and vertical dimension before committing to the definitive prosthesis.
Stage 1: 3D Printed Resin Temporaries
We designed and fabricated temporary bridges using 3D printed resin. These temporary bridges did two jobs. They let us check whether the new bite height was actually comfortable when he was eating, talking, and sleeping on it at home. They also gave his jaw muscles time to settle into the new position before we committed to the final zirconia.
Digital workflows using 3D printed provisional prostheses have become an essential part of modern implant rehabilitation. Research by Papaspyridakos et al. (2023) demonstrated that digitally fabricated prosthesis prototypes can achieve clinically acceptable fit through a complete digital workflow, making them a reliable tool for treatment planning.
After evaluating the first temporary bridge, adjustments were made and a second temporary was created. This iterative process allowed us to fine tune both the aesthetics and the functional bite relationship. After the second temporary, I was confident that the vertical dimension and overall appearance were exactly where my patient needed them to be.
Stage 2: The Final Multilayer Zirconia Bridge
With the ideal parameters confirmed through the temporary phase, we moved forward with the definitive restoration. The final bridge was fabricated in multilayer zirconia (shade B1) with a titanium bar for internal reinforcement.
Choosing zirconia over acrylic was a deliberate decision backed by strong clinical evidence. A long term study by Barootchi et al. (2020) compared zirconia and metal acrylic implant supported prostheses over an average follow up of 8.7 years. The zirconia prostheses demonstrated a significantly higher survival rate of 93.7% at five years compared to 83% for metal acrylic restorations, along with fewer overall complications.
Additionally, a six year clinical study by Ayna et al. (2021) found that ceramic restorations showed superior results in terms of reduced marginal bone loss and lower plaque accumulation compared to acrylic alternatives. A two year retrospective study by Cappare et al. (2021) also confirmed that monolithic zirconia prostheses had significantly lower plaque accumulation at probing sites (53%) compared to metal acrylic prostheses (76%).
The Result
After installing the final zirconia bridge, I performed careful adjustments to ensure a balanced and comfortable bite. The total procedure time from initial assessment to final restoration was approximately three months.
The patient walked out with a bridge that looks natural and feels solid when he bites down. Multilayer zirconia gives the teeth subtle colour gradients from the gum line to the edge, so they don't read as uniform white blocks. The titanium bar running through the bridge adds rigidity, which is where acrylic-only bridges tend to struggle over time.
Real case from our practice: fractured acrylic All on X bridge (left) and the multilayer zirconia replacement on the same implants (right). Shared with patient consent. Individual results may vary.
Why Zirconia for Full Arch Restorations?
Based on the current evidence, zirconia offers several meaningful advantages for All on X cases:
Stronger track record. Zirconia full-arch bridges show 93.7% survival at five years, compared with 83% for metal-acrylic (Barootchi et al. 2020).
Easier on the gums around your implants, with less plaque sticking to the surface and less bone loss at the implant margins.
Fewer repair visits over the years.
The colour isn't flat. Multilayer zirconia is layered so it shifts from warmer near the gum to more translucent at the edge, which is why it reads as natural.
Costs more upfront. You tend to save on repairs and remakes later (one study put complication rates at 53% for zirconia vs 76% for acrylic).
Key Takeaways from This Case
A few lessons worth taking from this case:
Acrylic bridge fracture is a well documented complication in All on X restorations, especially when the vertical dimension is not properly managed
A thorough examination can identify the root cause of failure, not just the symptoms
Using 3D printed temporary bridges before the final restoration allows for precise refinement of bite and aesthetics
Multilayer zirconia with a titanium bar holds up longer than acrylic and collects less plaque at the gum line
Healthy implants from a previous treatment can be preserved and built upon with the right approach
If you have an existing All on X restoration that has fractured or you are considering your options for a full arch solution, our team at ArtSmiles is here to help. Book a consultation to discuss what is possible for your smile. Every prosthesis we place is covered by our practice warranty.
Disclaimer
This article documents one patient's treatment at ArtSmiles. It is shared for educational purposes with the patient's written consent. Individual results vary and depend on factors including oral health, bone and gum condition, general medical history, and how well the restoration is maintained after treatment. Nothing in this article is a guarantee of outcome, a substitute for a clinical examination, or advice specific to your case. Any treatment carries risks and potential complications, which will be explained to you at consultation.
Before starting any dental treatment, book a consultation so we can assess your teeth, gums, and bone in person, take the imaging we need, and discuss the options, timelines, and costs that apply to your situation.
Case executed by Dr Cristian Dunker
General Dentist
AHPRA DEN0002257085
ArtSmiles, Southport, Gold Coast
Frequently Asked Questions
Why do acrylic All on X bridges fracture?
Acrylic resin is strong but not as strong as zirconia or metal. Over time, biting forces, bruxism, and a reduced vertical dimension of occlusion can cause the acrylic to crack or break. Mackert et al. (2024) reported that catastrophic acrylic fracture accounted for 61% of prosthesis replacements, with only 54% of acrylic bridges surviving five years.
If my acrylic bridge broke, are my implants ruined too?
Not usually. The implants and the bridge are separate components. In this case all four implants were healthy, well-integrated, and free of peri-implant disease, so we simply built a new zirconia bridge on top of the existing implant foundation. A clinical exam and X-ray will confirm whether your implants are still solid.
How long does a zirconia All on X bridge last?
The best long-term data we have comes from Barootchi et al. (2020), who followed zirconia full-arch bridges for an average of 8.7 years. At the five-year mark, 93.7% were still in service, compared with 83% for the older metal-acrylic style. We can't promise a number beyond that, but outcomes tend to be better when you keep up regular check-ups, clean around the bridge daily, and wear a night splint if you grind your teeth.
Why use 3D printed temporary bridges before the final zirconia?
Because you only get one shot at the final. 3D printed temporaries let us test the new vertical dimension, smile line, and bite in real life before we commit. In this case we went through two temporary bridges to lock in the right aesthetics and chewing position, then cut the zirconia to that exact prescription.
How long does a zirconia replacement take?
For this case, about three months from first consultation to final zirconia bridge, because the implants were already in place and healthy. If your implants need replacing or your gums need treating first, the timeline extends to 6 to 9 months. A 3D scan at consultation will tell us which path applies to you.
Written by Dr Cristian Dunker, BDSc, MBA.
Medically reviewed by Dr Cristian Dunker.
References
Mackert et al. (2024). Prosthetic complications and survival rates of metal-acrylic implant fixed complete dental prostheses. J Prosthet Dent. PubMed
Patzelt et al. (2014). The all-on-four treatment concept: a systematic review. Clin Implant Dent Relat Res. PubMed
Gittelson (2002). Vertical dimension of occlusion in implant dentistry: significance and approach. Implant Dent. PubMed
Papaspyridakos et al. (2023). Complete digital workflow for prosthesis prototype fabrication with double digital scanning. J Prosthodont. PubMed
Barootchi et al. (2020). Long-term clinical outcomes and cost-effectiveness of full-arch implant-supported zirconia-based and metal-acrylic fixed dental prostheses. Int J Oral Maxillofac Implants. PubMed
Ayna et al. (2021). Six-year clinical outcomes of implant-supported acrylic vs. ceramic superstructures according to the All-on-4 treatment concept. Odontology. PubMed
Cappare et al. (2021). Implant rehabilitation of edentulous jaws with predominantly monolithic zirconia compared to metal-acrylic prostheses. J Biol Regul Homeost Agents. PubMed
