ExternaL and Internal Connections - What is a Restorative Platform?
External and Internal Connections for dental implants refer to how the abutment (the part connecting the implant to the final crown or prosthesis) attaches to the implant fixture. These connections are crucial for ensuring stability, durability, and the overall success of the implant.
External Connection
An external connection features a protruding hexagonal or octagonal shape on the top of the implant fixture that fits into a matching slot in the abutment. This design, visible externally above the implant, was the first to be used in modern implant dentistry.
Benefits:
- Proven Track Record: External connections, such as the external hexagon (Brånemark system), have been utilised for decades and have well-documented success rates (Chrcanovic, Albrektsson, & Wennerberg, 2014).
- Ease of Use: The simpler design allows for easier handling and placement by the clinician (Siadat, Alikhasi, & Beyabanaki, 2016).
- Cost-Effectiveness: External connection implants are generally less expensive due to their long history and simpler manufacturing processes (Chrcanovic, Albrektsson, & Wennerberg, 2014).
Risks:
- Micro-Gap Concerns: The external hex design may create a micro-gap at the interface, increasing the risk of bacterial infiltration, which can lead to peri-implantitis and bone loss (Schwarz et al., 2018).
- Less Stability: External connections may provide less mechanical stability, especially in cases of lateral or rotational forces, making them less suitable for areas with high bite forces or in patients with parafunctional habits like bruxism (Chrcanovic, Albrektsson, & Wennerberg, 2014).
- Higher Risk of Screw Loosening: The design is more prone to screw loosening due to lateral forces applied during chewing (Siadat, Alikhasi, & Beyabanaki, 2016).
Internal Connection
An internal connection involves a hexagonal, octagonal, or conical shape that is recessed inside the implant fixture. The abutment fits into this internal space, creating a more secure and integrated connection.
Benefits:
- Enhanced Stability: Internal connections, such as internal hex or conical connections, provide improved mechanical stability due to a tighter fit between the implant and abutment, reducing the risk of micromovement (Chrcanovic, Albrektsson, & Wennerberg, 2014).
- Reduced Risk of Screw Loosening: This design disperses occlusal forces more evenly, lowering the chance of screw loosening or fractures (Schwarz et al., 2018).
- Improved Aesthetic Outcomes: Internal connections help maintain the soft tissue seal around the implant, enhancing aesthetic results, particularly in anterior regions (Siadat, Alikhasi, & Beyabanaki, 2016).
- Lower Risk of Bacterial Infiltration: The internal fit reduces the possibility of a micro-gap, thereby minimising the risk of bacterial infiltration and peri-implant disease (Schwarz et al., 2018).
Risks:
- Complexity: Internal connection systems are more complex and require precise placement, increasing the potential for complications if not properly executed (Chrcanovic, Albrektsson, & Wennerberg, 2014).
- Higher Cost: These implants tend to be more expensive due to advanced technology and tighter manufacturing tolerances (Siadat, Alikhasi, & Beyabanaki, 2016).
- Technical Skill Requirement: Proper handling and placement of internal connection implants may require a higher level of technical skill and experience (Schwarz et al., 2018).
We would like to acknowledge Dr. Manraj Kalsi for his insights and contributions to this page