Implant Considerations
According to the Journal of Clinical Periodontology glossary, a dental complication is defined as an unexpected event or outcome associated with dental treatment that negatively affects the patient's health, comfort, or the success of the treatment. This can include biological issues, such as infections or bone loss, as well as mechanical failures, such as fractures of dental restorations or implant components. Complications can arise during or after treatment and may require additional interventions to resolve.
Early implant failure is usually due to a failure of the implant to osseointegrate. This may be due to incorrect surgical technique, failure to achieve primary fixation, or infection, as well as systemic conditions which might leave patients pre-disposed to issues.
Systemic conditions can predispose patients to complications with dental implants, particularly when these conditions affect healing or immune response. Late implant failure is typically categorised into two main types:
- Biological Factors: Plaque-induced peri-implant disease is a primary cause of late implant failure. If peri-implantitis is not treated promptly, it can lead to significant crestal bone loss, resulting in implant mobility and eventual failure.
- Mechanical Factors: Unfavourable loading due to poor restorative design or occlusion can also lead to late implant failure. This can cause fractures in the implant, its components, or the restorative structure itself.
Early implant failures often occur unpredictably due to unforeseen factors. In contrast, late failures are often preventable with careful monitoring and appropriate patient guidance.
Preventing and Managing Peri-Implant Disease
Several factors can increase the risk of peri-implant diseases:
- Host Susceptibility: Patients with a history of periodontitis, uncontrolled diabetes, certain medications, heavy smoking, or immunosuppression are at higher risk. In such cases, meticulous plaque control is crucial to minimise the risk of peri-implant disease.
- Prosthesis Design: The design of the prosthesis should facilitate easy oral hygiene practices to ensure effective plaque control post-treatment.
- Implant Design: The surface roughness of the implant can affect its susceptibility to peri-implant diseases.
- Soft Tissue Considerations: The quantity and quality of the surrounding soft tissue play a significant role, with a thick, keratinised mucosa being ideal. Soft tissue grafting may be necessary to achieve optimal conditions.
- Patient Motivation: Ongoing patient education and motivation are essential to maintain oral hygiene and prolong the lifespan of the implant.
- Implant-Related Complications
- Implant complications can be broadly classified into biological, mechanical (technical), and aesthetic categories:
Biological Complications:
- Surgical issues such as haemorrhage, nerve damage, and mandibular fractures.
- Early implant loss due to factors like lack of osseointegration, infection, contamination, trauma, or overload.
- Peri-implant complications, including mucosal inflammation, soft tissue proliferation, dehiscence, fistula formation, and peri-implantitis.
- Malpositioned implants, which can often be avoided with careful preoperative planning.
Mechanical Complications:
- Fracture of the restoration, often due to excessive occlusal forces exceeding 200 N, as implants lack the shock-absorbing capacity of a periodontal ligament.
- Wear on the restoration or opposing teeth.
- Screw-related issues, including screw loosening or fracture, often caused by a lack of passivity between implant components, which increases internal stress and can lead to mechanical failure. An internal connection design with minimal taper (2–15°) is shown to have better mechanical performance than external connections (Gracis et al., 2012).
- Abutment-related issues, such as incomplete seating or abutment fracture.
- According to Salvi and Bragger (2009), factors that increase the risk of mechanical and technical complications include the absence of a metal framework in overdentures, cantilever extensions greater than 15 mm, bruxism, the length of the reconstruction, and a history of repeated complications. However, these factors do not necessarily affect the overall survival and success rates of implants.
Aesthetic Complications:
- White Tissue Aesthetic Issues: These include problems with the crown's position, alignment, shape, size, proportions, symmetry, colour, contour, and emergence profile.
- Pink Tissue Aesthetic Issues: Challenges like gingival recession, black triangles, asymmetry, and metal shadowing through the gingiva.
- The risk of aesthetic complications is elevated in patients with high aesthetic expectations, a prominent smile line, compromised periodontal tissues, and insufficient hard or soft tissues in the aesthetic zone (Fuentealba and Jofre, 2015).
- This comprehensive approach to understanding the factors that influence implant success underscores the importance of careful planning, patient education, and ongoing maintenance to prevent and manage complications effectively.
We would like to acknowledge Dr. Manraj Kalsi for his insights and contributions to this page