This lecture by Dr. Thomas Wiser addresses the critical difficulties and complications encountered in prosthetical implantology, emphasizing the necessary alignment between patient expectations, treatment strategy, and long-term success. The presentation begins by outlining the German Consensus Conference recommendations for implant numbers in various indications (fixed vs. removable restorations, edentulous jaws) and discusses the merits and risks of hybrid tooth-implant bridges. A significant focus is placed on procedural preferences, strongly advocating for screw-retained restorations over cemented crowns to prevent peri-implantitis caused by residual cement. The importance of meticulous planning is highlighted, including pre-treatment CMD screening and achieving passive, tension-free superstructure fit (verified using the Sheffield test). Dr. Wiser also introduces modern digital workflows, such as facial scanning, to enhance planning and patient communication. Finally, the lecture covers complexities in treating medically compromised patients (e.g., cancer, microstomia) and specialized craniofacial prosthetics, noting that magnetic attachments are superior for exoral rehabilitations, and emphasizing the legal necessity of comprehensive informed consent regarding all treatment risks and potential aesthetic limitations.
Complications in Prosthetical Implantology: Recommendations and Challenges
1:05 Patient Expectations and Costs: Patients expect long life, function, aesthetics, and few complications. Treatment cost is high, with follow-up costs approximating 10% of the original investment.
2:18 Lack of Standardized Guidelines: There are no regular recommendations for optimal implant length, diameter, or design; choices remain individualized.
2:47 German Consensus Recommendations: Provides specific guidelines for implant placement, such as requiring 8 ensuring posts (implants or stable teeth) for a fixed restoration in a reduced maxilla.
3:50 Mandibular Requirements: For missing anterior mandibular teeth, the standard recommendation is one implant substituting two teeth.
6:37 Hybrid Bridges: Combining teeth and implants (Her-Brit bridges) results in a 10% reduced survival rate compared to purely implant-supported bridges, but is a viable, lower-cost option requiring a rigid connection for stability.
11:23 Complications in Hybrid Bridges: Risks include carious tooth fracture, peri-implantitis, intrusion of teeth (if connection is non-rigid), and hardware fractures.
17:16 CMD Screening: Craniomandibular Dysfunction (CMD) screening is legally recommended (and often mandatory in Germany) before implant prosthetic rehabilitation.
17:52 Screw Retention Preferred: The speaker strongly favors screw-retained over cemented restorations, as cement residue is a known cause of peri-implant inflammation and subsequent failure. If cementing, abutments must be >4mm high.
21:02 Managing Complications: Complications in removable restorations are frequent but easy to manage. Complications in fixed restorations (e.g., chipping) are less frequent but require removal and repair, which is difficult.
22:06 Angulated Screw Retention: CAD/CAM technology allows vertical screw retention even if the implant axis and prosthetic axis differ by 20β25 degrees.
25:01 Inserting CAD/CAM Superstructures: CAD/CAM restorations lack stability until screwed in; a stabilizing palatal key is recommended, and screws should be inserted sequentially to prevent aspiration.
26:48 Informed Consent is Crucial: Comprehensive legal clearing up is mandatory; patients must be informed that an "optimal" cosmetic result (e.g., a "Hollywood smile") cannot be guaranteed, especially with compromised hard/soft tissue (29:11).
32:49 Digital Planning: Face scanners (e.g., Medi Smile) are used to match facial data with intraoral scans, allowing for virtual planning and better estimation of the final result for patient communication.
38:02 Addressing Microstomia: Reduced inter-arch distance makes standard prosthetic procedures difficult, necessitating specialized, long instruments for fixing and unscrewing abutments.
42:01 Impression Accuracy: The conventional open tray impression technique is generally considered more accurate than the closed technique. Digital scanning offers patient acceptance but accuracy may be reduced in the posterior region compared to conventional methods (52:42).
53:35 Implant Stability Testing: Implant stability is quantified using P-Test (negative value comfortable) and Resonance Frequency Analysis (ISQ value > 60 comfortable), guiding decisions on blocked vs. single restorations.
56:36 Tension-Free Fit: The Sheffield test (checking for a gap when the superstructure is fixed with only one screw) is essential to confirm passive fit, which prevents scaffold fractures.
1:00:00 Cancer Patients: In patients undergoing radiation therapy, implant positioning may be shifted to areas of lower radiation exposure to improve prognosis. All abutments and superstructures must be removed prior to radiation (1:00:44).
1:06:51 Orthodontic Risk: Implants should never be placed during active orthodontic therapy due to the risk of implant extrusion/movement, as demonstrated in a case study.
1:08:12 Exoral Craniofacial Prosthetics: For patients with facial defects, silicon epitheses fixed on implants are the preferred solution. Implants in the orbital area have a lower survival rate than those in the nasal or ear areas.
1:10:55 Magnetic Attachments: Magnetic abutments are currently the best choice for retaining craniofacial epitheses due to their reliable retention and ease of use.
1:30:46 Key Takeaway: Success in implant prosthetics relies on adhering to literature and guidelines, focusing on the entire treatment procedure (not just one phase), and performing technically exact work alongside thorough legal informed consent.