Amalgam Replacement: Biomimetic Onlays versus Composite Fillings

When considering dental restorations to replace your mercury amalgam fillings, particularly from a biological and health perspective, biomimetic onlays/inlays and composite fillings are both options that aim to restore the function and aesthetics of damaged teeth. However, these two approaches differ in their materials, techniques, and how they affect the tooth’s long-term health.

1. Definition and Materials
Biomimetic Onlays/Inlays:
Biomimetic dentistry focuses on mimicking the natural properties of teeth in both function and structure. Onlays and inlays are custom-made restorations typically made of ceramic or porcelain, designed to fit precisely into a damaged tooth.
These materials are chosen for their biocompatibility, durability, and ability to mimic the natural tooth’s biomechanics.
Composite Fillings:
Composite fillings are made of a resin-based material combined with glass or quartz particles, designed to fill cavities and restore minor tooth damage.
The material is applied directly to the tooth and hardened with a curing light. It’s generally used for smaller cavities and repairs.
2. Biological and Health Considerations
A. Strength and Durability
Biomimetic Onlays/Inlays:
Biomimetic onlays and inlays are designed to restore the tooth’s natural structure and integrity by reinforcing the remaining tooth, rather than removing more tooth material (as traditional crowns do).
These restorations are bonded using adhesive techniques that distribute force evenly, reducing the risk of fractures. They behave similarly to natural enamel in terms of strength and elasticity, making them more durable for large restorations.
Composite Fillings:
Composite fillings work well for smaller cavities but are less durable when used in larger restorations. The composite material can shrink over time, potentially leading to gaps or cracks in the filling.
In cases of extensive damage, composite fillings might need replacement or additional repairs.
B. Tooth Preservation
Biomimetic Onlays/Inlays:
One of the significant advantages of biomimetic onlays/inlays is their focus on tooth preservation. Since these restorations are bonded to the tooth structure with minimal drilling, they help maintain more of the natural tooth compared to other restorative techniques, reducing the risk of future issues.
Composite Fillings:
Composite fillings also allow for conservative tooth preparation. However, for larger cavities, more tooth material might need to be removed to ensure the filling adheres properly, which could weaken the tooth in the long run.
C. Biocompatibility and Health Impact
Biomimetic Onlays/Inlays:
The materials used in biomimetic onlays/inlays, such as ceramics and porcelain, are highly biocompatible, meaning they are well tolerated by the body and do not cause inflammation or immune responses.
Porcelain and ceramic do not contain toxins and are metal-free, which is ideal for patients looking for more natural, non-toxic solutions in dental care.
Composite Fillings:
While composite fillings are considered safe, some composites contain bisphenol A-glycidyl methacrylate (Bis-GMA), a derivative of bisphenol A (BPA), which has raised concerns regarding potential hormonal disruption. Although the amount of BPA exposure is minimal, patients sensitive to chemicals might prefer alternatives.
Composites can also break down over time, potentially exposing the body to the chemical compounds in the resin.
D. Risk of Secondary Decay
Biomimetic Onlays/Inlays:
Due to their excellent fit and bond to the natural tooth structure, biomimetic onlays/inlays create a tight seal that reduces the risk of secondary decay. Their ability to replicate the natural function and durability of teeth makes them less prone to micro-leakage, a common cause of decay beneath restorations.
Composite Fillings:
Composite fillings are more prone to micro-leakage as the material can shrink slightly during the curing process. This shrinkage creates small gaps between the filling and the tooth, which can allow bacteria to enter, potentially leading to secondary decay.
E. Longevity
Biomimetic Onlays/Inlays:
These restorations tend to last much longer than composite fillings. Their durability and resistance to wear and tear make them a better long-term solution for larger restorations, with an average lifespan of 10-20 years or more when properly maintained.
Composite Fillings:
Composite fillings typically last 5-10 years, depending on the size and location. Over time, they may need to be replaced due to wear, fracture, or recurrent decay.
F. Cost
Biomimetic Onlays/Inlays:
Biomimetic onlays/inlays tend to be more expensive than composite fillings due to the use of high-quality materials (such as porcelain) and the custom fabrication process in a dental lab.
Composite Fillings:
Composite fillings are generally less expensive and can be placed in a single dental visit, making them a more affordable option for smaller cavities or minor restorations.
3. Overall Health Impact
Biomimetic Onlays/Inlays:
From a biological and health perspective, biomimetic onlays/inlays are considered superior for larger restorations because they closely mimic the natural tooth’s structure and function. They reduce the risk of future dental issues, promote long-term tooth preservation, and are made from non-toxic, biocompatible materials.
Composite Fillings:
Composite fillings are safe for smaller cavities and offer an aesthetically pleasing result, but they may not be the best long-term solution for extensive restorations. For health-conscious patients concerned about BPA exposure or long-term durability, composite fillings may be less ideal compared to biomimetic restorations.
Conclusion
From a biological and health perspective, biomimetic onlays/inlays are a better option for long-term tooth preservation, durability, and biocompatibility, especially in cases of extensive tooth damage. They align with the body’s natural function and structure, reducing future dental complications. However, composite fillings offer a less expensive and quicker solution for small cavities but may pose potential concerns about BPA exposure and long-term durability.