This lecture by Dr. Thomas Wiser provides a comprehensive overview of complications in prosthetic implantology, focusing on treatment strategies, technical challenges, and patient management. Dr. Wiser details the official German "Consensus Conference" guidelines, which specify the recommended number of implants for various clinical situations, including single-tooth, partial, and fully edentulous restorations. He compares different prosthetic concepts, such as screw-retained versus cemented restorations, advocating for screw-retained solutions to avoid complications like peri-implantitis from cement remnants. The lecture highlights the importance of thorough pre-treatment planning, including mandatory CMD (Craniomandibular Dysfunction) screening in Germany, comprehensive legal informed consent, and the use of modern technologies like face scanners for aesthetic planning. Key technical aspects are covered, including a comparison of conventional and digital impression techniques, methods for quality control like implant stability testing (Periotest, RFA/ISQ), and ensuring a tension-free fit with the Sheffield test. The presentation concludes with a look at complex cases, including extraoral implants for craniofacial rehabilitation, where magnetic attachments are preferred, and a critical warning against placing implants during active orthodontic therapy due to the risk of extrusion.
A Clinician's Guide to Complications in Prosthetic Implantology
0:02:15 German Implant Guidelines: The German "Consensus Conference" provides specific recommendations for the number of implants required. For example, for a fixed, full-arch restoration, 8 implants are recommended in the maxilla (upper jaw) and 6 in the mandible (lower jaw). These guidelines serve as a standard for treatment planning and insurance purposes.
0:08:22 Hybrid Bridges (Implant-Tooth Supported): Combining implants and natural teeth in a single bridge is a viable option that is less expensive and surgical than a full implant solution. However, it has a ~10% lower survival rate and requires a completely rigid connection to prevent complications like tooth intrusion.
0:17:52 Screw-Retained vs. Cemented Restorations: The speaker strongly prefers screw-retained restorations. A key takeaway is that residual dental cement left below the gumline is a significant cause of peri-implantitis (inflammation and bone loss around an implant), which can lead to implant failure.
0:22:23 Modern CAD/CAM Solutions: Advanced CAD/CAM technology allows for angulated screw channels, enabling vertical screw-retained restorations even when implants are not perfectly parallel. This improves aesthetics and simplifies retrievability.
0:26:48 The Importance of Pre-Treatment Planning: A thorough "legal clearing up" (informed consent) is essential to manage patient expectations, especially regarding aesthetics. In Germany, a CMD (Craniomandibular Dysfunction) screening is mandatory by law before starting prosthetic treatment.
0:32:49 Advanced Planning with Face Scanners: New technology allows clinicians to merge 3D facial scans with intraoral scans. This helps in designing restorations that are in harmony with the patient's facial features and allows the patient to visualize the potential outcome.
0:42:01 Impression Techniques Compared: While the open-tray conventional impression technique is considered highly accurate, digital intraoral scanning offers better patient comfort and is superior for capturing the position of angulated implants. However, its accuracy can decrease in posterior, full-arch situations.
0:53:35 Critical Quality Control Checks: The stability of each implant should be quantitatively measured using tools like the Periotest or Resonance Frequency Analysis (ISQ values). Additionally, the passive, tension-free fit of the final prosthesis must be verified (e.g., using the Sheffield test) to prevent mechanical stress and fractures.
1:01:07 Common Complications and Positioning Errors: Poor three-dimensional implant positioning is a major cause of prosthetic failure, making it impossible to create a functional and aesthetic restoration. Other common issues include screw loosening and fracture of veneering materials, especially in patients with bruxism (teeth grinding).
1:06:26 Critical Warning on Orthodontics: A crucial clinical pearl is to never place an implant while a patient is undergoing active orthodontic therapy. Because an implant is fused to the bone (ankylosed), orthodontic forces can cause it to be moved out of position (extruded) along with the surrounding bone.
1:07:38 Extraoral Implants for Craniofacial Defects: The lecture covers the specialized use of implants to retain facial prostheses (e.g., for the eye, nose, or ear). Magnetic attachments are identified as the most effective retention system. Survival rates for these implants are highest in the ear area, followed by the nasal area, and are lowest in the orbital (eye) area.