Dr. Paul Weigl

Paul Weigl_260x260pxJW Goethe-University Frankfurt am Main
Head of Department of Postgraduate Education
Faculty of Oral and Dental Medicine

Dr. Paul Weigl graduated from the University of Munich Dental School in 1989. Since 1992 he has worked as an assistant professor and director of preclinical studies for the Department of Prosthodontics of the Johann Wolfgang Goethe-University Frankfurt am Main. Dr. Weigl has special focus in the field of prosthetics on implants. He is also a senior specialist at the Dept of Prosthodontics, University of Frankfurt. Additionally he runs a R&D project to develop a fully automatic working CAD/CAM process to manufacture complete crowns and bridges and to develop a new fs-laser based device for diagnosis and minimally invasive therapy of caries. His new Department of Postgraduate Education offers the master course “Master of Science of Oral Implantology” (www.moi.uni-frankfurt.de). The Department currently have 295 participating Master students from about 48 nations.

Lecture titles:

 “The Socket Chamber Concept for Immediate Placed Implants”

The secondary wound healing of an extraction wound can be changed in a primary by sealing it with a root-shaped component immediately after tooth loss. The resulting chamber is filled with blood which has a very high potential for healing and for new bone formation. This “Power of Healing” should advantageous used in the immediate implant placement, too.

An aggressive implant thread design is required to obtain a sufficient primary stability at a fresh extraction socket. A minimally invasive treatment work flow is mandatory: a flapless tooth extraction, the assembly of the final abutment (one abutment one time) and the insertion of a temporary crown with non-functional occlusion. Later has to seal and to support the peri-implant soft-tissue with a root shaped cervical part. In consequence a deep crown margin at a stock abutment occurs and forces to an extraoral cementation technique avoiding cement excess [1]. The blood-filled chamber completely ossified alone by healing [2] – the placement of membranes and bone replacement materials in case of a lack of buccal bone lamella loses its dogmatic required application [3]. This kind of immediate restoration simulates a tooth-reimplantation in the transition zone. It ensures the preservation of the original emergence profile including papillae.

At the completion of this lecture, participants will be able to:
– Recognize that a extraoral cementation technique minimize cement-associated per-implant marginal bone-loss.
– Understand that implants placed in fresh extraction sockets have to have an aggressive thread design for an immediate restoration creating a primary healing and a blood chamber for a complete    ossification.
– Become familiar with the universal two appointments work-flow for implants replacing a lost single tooth.

References:

[1] Frisch E., Ratka-Krueger P., Weigl P., Woelber J.:Extraoral cementation technique (ECT) to minimize cement-associated peri-implant marginal bone-loss: Can a thin layer of zinc oxide cement provide sufficient retention?Int J Prosth; July 2015
[2] Mainetti T, Lang NP, Bengazi F, Favero V, Soto Cantero L, Botticelli D. Sequential healing at implants installed immediately into extraction sockets. An experimental study in dogs. Clin Oral Implants Res. 2014 Dec 18.

[3] Sarnachiaro GO, Chu SJ, Sarnachiaro E, Gotta SL, Tarnow DP.

Immediate Implant Placement into Extraction Sockets with Labial Plate Dehiscence Defects: A Clinical Case Series. Clin Implant Dent Relat Res. 2015 Apr 27.

■ Challenges of Single Tooth Restoration in Implant Dentistry”

Media, social networks and positive opinions within the social environment of satisfied patients contributed to the high level of awareness of dental implants. This leads to a decreasing use of a three-unit bridge after a singular tooth loss. A single tooth crown is thus the most common type of suprastructure on implants. In respect to the anterior and posterior region of the oral cavity the importance of two requirements changes: aesthetics vs. strengths.

In the esthetic zone especially the selection of abutments correlates with the vertical positioning of the implant. The latter also depends on the oro-vestibular dimension of alveolar ridge. If a mid-facial-level is predictable with no or a minor (< 1 mm) apical loss compared to the natural contralateral tooth, a vertical tissue augmentation can be avoided. Furthermore, there is a choice how the peri-implant soft tissue is shaped: by the abutment or by the cervical part of the crown. Later influences the selection of the abutment material – titanium vs. ceramics. In sum, it is more important the shape, color and the preservation of the soft tissue than the load capacity of an implant.

The molar region is known for the highest masticatory forces. In case of a single tooth loss they cannot be distributed to neighboring implants and thus reduced per implant. The following recommendations should be considered to minimize the risk of overload or rapid fatigue of implant components:

– shortest possible vertical distance between the implant platform and the occlusal plane. In consequence a sub-crestal placement more than 0.5 mm should be avoided.
– precise occlusal adjustment, in particular the removal of all contacts in the laterotrusion, mediotrusion and retrotrusion.
– no single crown restoration filling a gap of more than one molar, particularly in narrowed gaps after the loss of two adjacent teeth.
– patients with severe bruxism should wear an occlusal splint overnight.

Conclusion: The risk of a technical failure can be reduced by a vertical/horizontal minimizing of the single molar crown to nature-like dimensions and a correct adjusted occlusion. Therefore, the huge vertical cantilever which mostly occurs at short implants (<6 mm) is close to the borderline of the mechanical strength of an implant.

At the completion of this lecture, participants will be able to:
– recognize the correlation between vertical implant positioning, oro-vestibular alveolar ridge dimension and right choice of abutment design for esthetic solutions at soft-tissue zone.
– become familiar for different soft tissue shaping methods: abutment vs. cervical part of a crown.
– understand the risk factors and their minimization for implant/abutment fractures
– recognize the special loading situation at single molar crowns anchored by single implants.

CV

Dr. Paul Weigl, born 08/24/1963 in Munich, Germany

1983-1989 Study of oral medicine and operative dentistry at the Ludwig-Maximilians-University Munich

1989  university degree

1990  conferral of a doctorate Dr. med. dent.

1989-1992 scientific staffer at the Department of Prosthodontics of the

Ludwig-Maximilians-University Munich

1992  scientific staffer at the Department of Prosthodontics of theJohann Wolfgang Goethe-University Frankfurt am Main

1993  assistant professor, management of preclinic study section at theDepartment of Prosthodontics of the Faculty of Oral and Dental Medicine,Johann Wolfgang Goethe-University Frankfurt am Main

1994  headship of field of prosthetics on implants

1996. headship of R&D of a fully automatic CAM/CAM process chain

2001  Lecturer of qualified post graduate education in implantology

2002  Degree of an advanced prosthodontics (German scientific associationof Prosthodontics)

2007  assistant professor, management of clinic study section at theDepartment of Prosthodontics of the Faculty of Oral and Dental Medicine,Johann Wolfgang Goethe-University Frankfurt am Main

2008  Establishing a Master of Science „Oral Implantology“http://www.moi.uni-frankfurt.de/

2009  Controllership of the Master of Science „Oral Implantology“

2012 Head of Department of Postgraduate Education of the Faculty of Oral and

Dental Medicine, Johann Wolfgang Goethe-University Frankfurt am Main

Main focus of scientific work:

–  Prosthodontics on implants is investigated by four prospective clinic trails. An effective prosthetic protocol is evaluated for its aesthetic result. Furthermore the integration of residual teeth in    suprastructures is assessed.

–  Two prospective clinical trials evaluating immediate placement and restoration of implants at the aesthetic zone

–  RCT of full anatomical ZrO2 Crown & Bridges borne on implants

–  Development of fully-automatic system for evaluation of tooth preparations

–  Development of new fully-automatic working CAD/CAM-systems.

–  Development of a new manufacturing tool for NC-controlled shaping of ceramics

–  Development of a wear-free telescopic retainer for removable dentures for geriatric patients