Niklaus LANG

Professor of Implant Dentistry, The University of Hong Kong 2008-2012,   Professor Emeritus, University of Berne, Switzerland, Chairman 1980-2008;
Dr. odont. h.c., Aristotle University of Thessaloniki, Greece, 2011, Honorary Professor University of Aarhus, Denmark 2006-2011; Odont. Dr. h.c., University of Gothenburg, Sweden, 1997; Honorary Fellow RCPS Glasgow, 1995; Dr. odont. h.c., University of Buenos Aires, Argentina, 1994; Dr. odont. h.c., University of Athens, Greece, 1989; PhD, University of Berne, 1978; Master of Science in Periodontics, University of Michigan, Ann Arbor, 1975; Dr. med. dent., University of Berne, 1970;
Honorary Professor: The University of Hong Kong 2013-2019, University College London 2012 -, University of Zürich 2013 -, Honorary Research Consultant National Dental Centre of Ingapore 2013-2019
Guest Professor University of Otago, Dunedin, New Zealand, 2008, National University of Singapore, 2002, 2004, 2007, 2009, 2013; University of Michigan, USA, 2005, University of Göteborg, Sweden, 2000, University of Queensland, Brisbane, Australia, 1999/2000, University of Aarhus, Denmark, 1994, The University of Hong Kong, 1994, University of Texas, Health Science Center at San Antonio, Texas, USA, 1986; Professor Extraordinario, Universidad Autonoma de Nuevo Leon, Monterrey, Mexico, 1980. 
Published over 640 articles in peer-reviewed scientific journals and several textbooks (h-Index: 88). Over 3000 lecturs in 5 continents.  Editor-in-chief emeritus: Clinical Oral Implants Research 1990-2016,
Honorary member of: the American Academy of Periodontology AAP, the Danish, German, Helenic, Italian, Lithuanian, Slovenian, SouthAfrican and Swiss Societies of Periodontology, Danish Society for the Study of Periodontology, Italian Society of Osseointegration, International Team of Implantology (ITI), Australian-New Zealand Academy of Periodontology (ANZAP), Ukrainian Academy of Periodontology (UAP)
German Society of Implantology (DGI). Platinum medal of the Spanish Society of Periodontology and Implant Dentistry SEPA,  Distinguished Scientist Award of the EFP 2015, Honorary member of the British Society of Periodontology (BSP), Norton M. Ross Award for Excellence in Clinical Research of the American Dental Association,

 

What is the value of a tooth ? What is its longevity ?

 

Answering these questions is certainly not an easy enterprise and probably best dealt with by stating: "It just depends". However, for the practicing dentist a relatively reliable answer is of utmost importance, especially when reconstructions are planned to restore adequate function, obtain satisfying esthetics and obtain and maintain oral health. Therefore, the questions will be answered for various situations: For the healthy tooth with an almost intact periodontal support, for the periodontally compromised, but successfully treated abutment tooth, for the devitalized, but root canal treated tooth, for the endodontically compromised tooth with periodical pathology. These discussions will emphasize the importance of maintaining natural teeth even if they are affected by pathological findings. Post therapeutic treatment prognoses are well documented, especially for survival and complication rates of fixed partial dentures on tooth abutments, on implants and on both tooth and implant abutments. The major question is not to discuss the alternative between tooth abutments versus implant abutments, but to discuss predictability and longevity of teeth following active periodontal or endodontic therapy. In that respect, implants do not provide a higher value to the patient. They are not chosen to replace teeth, but to help replace already missing teeth. It has to be realized that that the long- term documentation of implant survival and complication rates are at its best 10 years old and that none of the systems sold today have more than 5-year data to offer. However, even for teeth jeopardized by periodontal or endodontic conditions the literature provides a number of long-term studies to answer the above proclaimed questions with high reliability always considering the single patient situation with great respect.

 

Morphogenesis of the Peri-Implant Soft Tissue Seal


Mandibular premolars were extracted in 20 Labrador dogs. After a healing period of 3 months, four Implants (ITI Dental Implant System) were placed in the right and left sides of the mandible. A non-submerged implant installation technique was used and the mucosal tissues were secured to the conical marginal portion of the implants with interrupted sutures. The sutures were removed after 2 weeks and a plaque control program including daily cleaning of the remaining teeth and the implants was initiated. The animals were sacrificed and biopsies were obtained at various intervals to provide healing periods extending from Day 0 (2 h) to 12 weeks. The mandibles were removed and placed in the fixative. The implant sites were dissected and processed for histological analysis.
Large numbers of neutrophils infiltrated and degraded the coagulum that occupied the compartment between the mucosa and the implant during the initial phase of healing. At 2 weeks after surgery, fibroblasts were the dominating cell population in the connective tissue interface but at 4 weeks the density of fibroblasts had decreased. Furthermore, the first signs of epithelial proliferation were observed in specimens representing 1-2 weeks of healing and a mature barrier epithelium occurred after 6-8 weeks of healing. The collagen fibers of the mucosa were organized after 4-6 weeks of healing.
It is suggested that the soft-tissue attachment to implants placed using a non-submerged installation procedure is properly established after several weeks following surgery.