The long and the short of it

22 December 2023

Short or long dental implants? Zaki Kanaan asks which is better.

Short or long dental implants? Zaki Kanaan asks which is better.

With growing patient demand for alternatives to traditional dentures, there is little doubt that as a population, we are becoming more aware of the options when it comes to dentistry. Treatments such as dental implants are among the most common enquiries to the Oral Health Foundation.

Osseointegration is critical for implant stability and is considered a prerequisite for implant loading and long-term clinical success. In many clinical situations, insufficient bone volume is a key limiting factor for dental implant placement and successful osseointegration. The choice of implant length and diameter can play a critical role in the success of the treatment.

Short resort

While surgical techniques to obtain adequate bone volume, such as bone grafts, sinus lifting, and nerve transposition, are an option, these surgeries are technique-sensitive and might cause significant postoperative complications such as graft resorptions, severe pain or neurosensory disturbances. Short dental implants have been proposed as a simpler, cheaper, and faster alternative for the rehabilitation of atrophic edentulous areas to avoid the disadvantages of these surgical techniques.

It should be noted that the definition of short dental implants is somewhat controversial. Dental implants with intra-bony lengths of less than 10mm, 8mm or 7mm are all defined as short implants in different studies.

Longer dental implants typically measure above 10mm in length. They offer increased implant stability due to their greater length and deeper integration into the jawbone. This can be particularly advantageous for patients with compromised bone quality or those who require support for multiple crowns or bridges. They are often preferred for aesthetic reasons, as they can provide better support for prosthetic materials, resulting in improved natural appearance and enhanced patient satisfaction. Their longer length allows for better emergence of soft tissue, creating a more natural appearance.

Diameter decision

The diameter of the implant is also important. When the diameter of an implant is increased, the contact area between the implant and the bone is increased, and therefore, it increases the stability of the implant. It is believed that wider diameter implants reduce the stress around the crestal bone and potential bone loss.

Indeed, the diameter is considered more important than the implant length in the distribution of loads to the surrounding bone. At least 3.25mm in diameter is required to ensure adequate implant strength, and most implants are approximately 4mm in diameter. Implants with larger diameters are more stable and others with smaller diameters have been shown to have a better performance when increasing their length.

Short and longer implants show similar survival rates after one year of loading. However, the marginal bone loss around short implants placed in the atrophic area has been shown to be lower than in longer implant sites placed in the augmented bone area of posterior regions of maxillaries.

It is notable that the implant loading protocol (delayed vs immediate) does not influence the performance of narrow diameter implants. The implant survival rate is 97.4 per cent for long implants and 95.4 per cent for short implants. Immediate loading seems to not jeopardise the survival of or bone stability around short implants either.

Careful considerations

It is imperative that when choosing between short and long dental implants, clinicians take several considerations into account, including:

  • Bone quality and quantity: Assessing the patient’s bone structure and volume is fundamental to determining the suitability of either short or long dental implants
  • Prosthetic requirements: Determining the number and type of prosthetic elements influences which implant length is most appropriate
  • Patient preferences and expectations: Understanding patient preferences and expectations is essential. Nervous patients may prefer to avoid the surgical techniques that accompany the use of longer implants.

Staying on top of topics like this is part and parcel of the benefits of becoming a member of the Association of Dental Implantology (ADI). On top of presenting great opportunities to network with experts in the field, ADI full members also receive free premium membership of Dentinal Tubules as part of their ADI membership package. Dentinal Tubules offers access to a wealth of knowledge, with a huge online content library featuring top dental educators speaking on the latest clinical techniques, business learning and core compliance topics. Online resources including webinars, articles and case studies, are available 24/7, making it easy for members to fit studying into a busy schedule and to complete their CPD/CE. 

Both short and long dental implants offer distinct advantages that can be tailored to meet individual patient needs. Short dental implants provide minimally invasive treatment options, while long dental implants offer enhanced stability and aesthetic outcomes. The selection of the appropriate implant type should be based on clinical assessment, considering factors such as bone quality, prosthetic requirements, and patient preferences.

 

For more information visit www.adi.org.uk

References available on request.