In the ever-evolving field of dentistry, the combination of natural teeth and dental implants in fixed restorations presents a unique challenge and opportunity. In a recent EAO session, Professor Florian Beuer from the Charité University in Berlin shed light on this complex topic. Here’s a comprehensive overview of his insights.
The Context and Relevance Combining natural teeth with dental implants in fixed restorations is akin to bridging two different worlds. Historically, this technique was viewed with skepticism due to the differing behaviors of teeth and implants under load. Teeth, with their natural periodontal ligament, exhibit mobility, while implants are rigidly fixed in bone. This discrepancy has led to concerns about the long-term success of such restorations. However, as Professor Beuer points out, despite the challenges, this approach remains relevant, particularly when addressing patient-specific needs and constraints.
Key Drivers for Combining Teeth and Implants The primary motivations for considering this type of restoration include:
Preservation of Natural Teeth: Maintaining as many natural teeth as possible is beneficial for both biological and psychological reasons. Reduction of Surgical Invasiveness: By utilizing existing teeth, the number of implants and the extent of surgical intervention can be minimized. Cost Considerations: Fixed restorations that combine teeth and implants can be more cost-effective compared to placing multiple implants. Scientific Evidence and Clinical Practice Despite its practical application, scientific literature on the subject is sparse. Professor Beuer highlights that there are only a few studies, with just 185 restorations reviewed over 30 years. This limited data stems from concerns about complications historically associated with such restorations, particularly the fear of differential mobility between teeth and implants.
Addressing Complications: Mobility and Material Considerations One of the major complications in combining teeth and implants is the differential mobility. Natural teeth can move slightly due to their periodontal ligament, while implants do not. This difference can lead to stress and potential failure of the restoration. Historically, prosthetic solutions included using attachments that allowed for some movement, but this often resulted in biological complications such as intrusion of natural teeth.
Professor Beuer recommends a rigid connection between teeth and implants, preferably using cemented restorations. While metal-ceramic materials have been predominantly studied, there is a growing interest in all-ceramic materials like zirconia, especially in posterior restorations, despite the current lack of long-term data.
Practical Considerations and Technical Tips When planning such restorations, several technical aspects must be considered:
Distance Between Implant and Tooth: Studies suggest that three to four unit bridges are optimal, with the best performance seen in restorations replacing up to two teeth. Rigid Connection: A cemented, rigid connection is crucial for the success of the restoration. Material Choice: Although metal-ceramic has the most data, zirconia is emerging as a promising material for these restorations. Complications to Watch For Common complications include ceramic fractures and issues with abutments. However, the most concerning are secondary caries and the potential loss of retention on natural abutments, which can lead to tooth extraction. Regular monitoring and meticulous maintenance are essential to mitigate these risks.
The Cantilever Question An interesting query from the audience addressed whether a cantilever bridge on implants might present fewer complications than combining teeth and implants. Professor Beuer notes that while cantilever bridges should not exceed 8mm in length to avoid increased marginal bone loss, combining teeth and implants might still be preferable in certain clinical situations.
Conclusion Combining natural teeth and dental implants in fixed restorations is a nuanced approach that requires careful planning and consideration of various factors. While the scientific evidence is limited, clinical experience and ongoing advancements in materials and techniques continue to support its viability. For practitioners, understanding the potential complications and adopting a meticulous, patient-centered approach is key to success.
For more detailed discussions and to engage with experts like Professor Beuer, the EAO’s live sessions and after-discussion lounges provide valuable platforms for learning and professional development.