Implantology Step by Step

Christoph T. Sliwowski

IMPLANTOLOGY

STEP BY STEP

2nd Edition, fully revised and extended

Co-authors:

Stefan Hümmeke

Dominika Sliwowska

Christian F. J. Stappert

London, Berlin, Chicago, Tokyo, Barcelona, Beijing, Bucharest, Istanbul, Milan, Moscow, New Delhi, Paris, Prague, Riyadh, São Paulo, Seoul, Singapore, Warsaw and Zagreb

2nd Edition, fully revised and extended

A CIP record for this book is available from the British Library.

ISBN:
978-3-86867-291-6 (ebook)
978-1-85097-281-5 (print)

Quintessence Publishing Co. Ltd,

Grafton Road, New Malden, Surrey KT3 3AB,

United Kingdom

www.quintpub.co.uk

Copyright © 2015

Quintessence Publishing Co. Ltd

All rights reserved. This book or any part thereof may not be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher.

Translation: Rosana Jelaska

Editing: Quintessence Publishing Co. Ltd, London, UK

Layout and Production: Janina Kuhn, Quintessenz Verlags-GmbH, Berlin, Germany

Printed and bound in Germany

Introduction

Dear reader, dear colleagues,

A few years ago saw the publication of the two-volume work Implantologie Step by Step, starting with part I “Maxilla” and followed by part II “Mandible,” in both German and Polish. Interest in a practical implantology “cookbook” was great and both volumes quickly became bestsellers. Since then, implantology has evolved with such speed that it seemed a good idea to revise both volumes fully, and to update and extend them. The result is now in your hands.

The division into maxilla and mandible has been retained, but the two parts have now been brought together in a single volume. Sub-sections covering the anterior and posterior regions and the edentulous jaw have also been retained. A section on totally edentulous patients has been added for the sake of completeness. Chapter 3 entitled “The Edentulous Mandible” has been totally revised, describing not only the cantilever fixed bridge but also the new Sliwowski Overdenture System concept. This technique makes it possible to provide the patient with a high-quality immediate restoration on a minimally invasive and economic basis.

The diagnostic tools and treatment plan are outlined before each treatment is described. One new feature is that the year when the treatment began is given in the summary at the end of each case, alongside the treatment course and timings of the various procedures. The aim of this is to allow you to place the treatment on the developmental timeline of implantology. Another new addition to the case reports is the “Continued follow-up” section, which may span a number of years, allowing better evaluation of the long-term results. As in the first edition, both general and important additional information relating to the described cases is highlighted under the “Note” or “Attention” headings.

The authors’ attitude to the presented material has also changed. We present not just a selection of “good” and successful cases, but also those particularly critical, controversial and problematic ones which can teach us a lot, but which we practitioners rarely bring to light in the normal course of things, and usually prefer to keep “in the drawer.”

Along with long-established and tried-and-tested concepts, this book also gives consideration to further developments and current trends in implantology. Conventional 2D diagnosis is becoming more and more a thing of the past and is being replaced by 3D diagnosis and planning. The availability of cone beam computed tomography (CBCT) scanners continues to grow, making this type of diagnosis a reality. The immediate non-functional and functional loading of implants is also increasing, often replacing the conventional load-free healing period of implant treatment.

Finally, I would like to extend my most cordial thanks to all our readers for their huge interest in the previous edition, and wish all our colleagues lots of enjoyment in referring to this book and much success with the treatment of their patients.

Christoph T. Sliwowski

Zahnimplantat Klinik Düsseldorf,

November 2014

Authors

Dr Med Dent Christoph T. Sliwowski

Christoph T. Sliwowski studied Dentistry in Warsaw (graduating in 1982). He has been practicing in Germany since 1987. Since 1989, his main interest has been implantology; in 1995, he took his doctorate in this subject with Prof Hubertus Spiekermann in Aachen. Since 1997, his main focus of activity has been in implantology, and since 2003 he has been an Accredited Implantology Specialist with the German Society for Dental Implantology (DGZI) and the European Association of Dental Implantologists (BDIZ EDI). From 1998 to 2008, he was Medical Superintendent at the Zahnklinik Rhein-Ruhr, a specialist clinic for implant dentistry and esthetics in Mülheim on the Ruhr. Since 2010, he has been Director of the Zahnimplantat Klinik Düsseldorf, a dental implant clinic that he set up at the St. Vinzenz Hospital in Düsseldorf.

Dr Sliwowski is a member of several implantology societies, including the German Society for Implantology (DGI), the German Center for Oral Implantology (DZOI), BDIZ and the Polish Association of Implant Dentistry (OSIS); he is an Active Member of the DGZI and Diplomate of the International Congress of Oral Implantologists (ICOI). Since 2003, he has been a consultant for continuing professional development with the BDIZ, the German Association of Oral Surgeons (BDO), the German Association for Oral and Maxillofacial Surgery (DG MKG), DGI and DGZI. Since 2007, he has acted as an expert assessor with the BDIZ EDI and as Vice-President of the Polish Medical Association in Germany (Polnische Medizinische Gesellschaft in Deutschland e. V.).

Dr Sliwowski is also author of the patent for the Sliwowski Overdenture System, an innovative restoration concept for the edentulous mandible.

Dr Med Dent Stefan Hümmeke

Stefan Hümmeke, born in 1972, studied Dentistry at the University of Münster, Germany and took his doctorate in dentistry in 1998. In 2003, after several years of further training, he was awarded the title of Dental Surgeon Specialist in Oral Surgery.

From 2001 to 2007, he worked at the Department of Oral and Maxillofacial Surgery at the Klinikum Osnabrück hospital in Osnabrück, Germany, as Senior Staff Member from 2004. From 2007 to 2009, he worked with Prof E. Esser at the Implantat Centrum Osnabrück (ICOS) center for implant treatment. In January 2010, he founded the oral surgery center Oralchirugie Osnabrück (OCOS) and set up his own oral surgery and implantology practice in Osnabrück.

The main focus of his work is on all-ceramic restorations, along with imaging investigations and the surgical implementation of virtual implant planning by navigation surgery and stereolithographic surgical templates.

Dominika Sliwowska, DDS

Dominika Sliwowska studied Dentistry in Poznan´, Poland from 2004 to 2009, graduating as a Doctor of Dental Surgery (DDS). From 2010, she was Assistant Dentist and, since 2013, she has been Junior Partner at the Zahnimplantat Klinik Düsseldorf, the dental implant clinic at the St. Vinzenz Hospital in Düsseldorf, Germany. Her key activities include implant-supported prosthodontics, periodontology and the treatment of peri-implantitis.

Dr Med Dent Habil Christian F. J. Stappert, DDS, MS, PhD

Christian Stappert studied Dentistry and earned his doctorate and DDS from the Johannes Gutenberg University Mainz, Germany. After working as an Assistant Professor and research associate at the Department of Prosthodontics at the University RWTH Aachen, Germany (under Prof H. Spiekermann), from 1997, he continued his postgraduate Prosthodontics training at the Department of Prosthodontics (Prof J. R. Strub) of the Albert-Ludwigs University in Freiburg, Germany (as Senior Staff Member from 2001), where he gained his postdoctoral teaching qualification in 2008, in the key area of prosthodontics.

Until March 2012, Dr Stappert worked as Director of Aesthetics and Periodontal Prosthodontics at the Department of Periodontology & Implant Dentistry (under Prof D. Tarnow) and also as Chief Research Officer at the Department of Biomaterials & Biomimetics (under Prof Dr V. Thompson) of the New York University College of Dentistry. He is currently Professor and Director of Implant Periodontal Prosthodontics at the Department of Periodontics at the University of Maryland School of Dentistry.

His research focus is on ceramic materials and restorations. He has published internationally on these topics and is an editorial board member of several learned journals in his field.

Acknowledgments

First, I would like to extend my very warmest thanks to my co-authors, Dr Christian F. J. Stappert, Dr Stefan Hümmeke and my daughter and Junior Partner Dominika Sliwowska, DDS, for the outstanding collaborative work involved in producing this book.

My most particular thanks must go to my wife, Dr Beata Sliwowska, for her support in working on this book and for patiently and repeatedly proofreading the manuscript.

I want to give my warmest thanks to my former business partners and colleagues Dr Michael Weber and Dr Ali Alexander Pacyna for their close and confidential collaboration in the joint treatment of our patients.

Thanks must go to my prosthodontist colleagues Dr Roland Althoff, Dr Gregor Cwajgart, Dr Uwe Hildebrand, Dr Eberhard Helbig, Dr Hubertus Klaus, Dr Barbara Wonschik and Dentist Markus Peters for our first-class and successful collaboration.

I want to thank my former assistants, Sahra Osmani, Andrea Graf, Dorothea Vogel, Christel Kloster, Andrea Terjung-Jahn, Caroline Wojtynowski, Gülcan Cek and Aldijana Gashi, as well as my current assistants at the Zahnimplantat Klinik Düsseldorf, Andrea Karst, Sandra Bohnen and Anna Schmiebusch, for their dedicated work and assistance in the treatment of patients and for the accompanying photographic and radiologic documentation.

Similarly, I would like to give very special thanks to my former dental technicians, Horst Mosch, Fernando Abrantes, Ute Olbers, Ivonne Levik, Olaf van Iperen, Gerhard Makowski, Willi Knepper and Jochen Essel, along with the technicians at DentaLab, Ludger Jansen, Marian Jansen, Ingo Gleichner and Frank Paffrath, for their careful planning and painstaking creation of prosthetic devices.

To the management of Quintessenz Verlags, Dr Horst-Wolfgang Haase, Christian Haase and Johannes Wolters in Berlin, along with Ireneusz Czyzewski and Iwona Koziel in Warsaw, I give thanks for the huge dedication without which this book would never have come into existence.

Christoph T. Sliwowski

Contents

Chapter 1 The Anterior Mandible

3D diagnosis and planning

Pronounced residual ridge atrophy

Shortage of space, insufficient distance to the neighboring teeth

Single-tooth gap

Typical treatment course

Late implant placement with immediate loading

Atypical treatment course – problematic baseline situation

Immediate implant placement following extraction

Note: Narrow and high gap between neighboring teeth

Problems and complications

Horizontal augmentation of a knife-edge residual ridge

Immediate restoration

Immediate implant placement and immediate loading

Multi-tooth gap

Typical treatment course

Replacement of three incisors on two implants

Atypical treatment course – problematic baseline situation

Preventive horizontal augmentation

Problems and complications

Implant placement in an extensive bone defect

Immediate loading

Immediate fixed partial denture loaded onto definitive implants

Flapless implant placement and augmentation with immediate loading

Chapter 2 The Posterior Mandible

3D diagnosis and SimPlant planning

3D planning of a single-tooth implant

3D planning of a free-end situation

Single-tooth gap

Typical treatment course

Replacing a molar with two implants

Replacement of a molar with an implant with vertical mucosal distraction

Atypical treatment course – problematic baseline situation

Replacement of a molar with one implant in a large gap

Problems and complications

Fracture of a non-WP implant

Note: Iatrogenic complication with nerve involvement

Immediate loading

Immediate provisional loading of a definitive implant

Multi-tooth gap and free-end situation

Typical treatment course

Two-session approach with augmentation

Atypical treatment course – problematic baseline situation

Single-session approach with augmentation and transmucosal healing

Large bone defect following the loss of implants

Problems and complications

Fracture of an implant with a tooth/implant-supported fixed partial denture

Failed augmentation with a bone block in a patient with an extremely narrow residual ridge

Immediate loading of provisional implants

Typical treatment course

Bilateral free-end situation

Atypical treatment course

Customizing provisional implants

Problems and complications

Loosened blade implant, provisional implants to protect the augmentation material

Immediate loading of definitive implants

3D implant planning and its surgical implementation

Diagnostic possibilities of cone beam CT imaging

Stereolithographic surgical guides

Implant placement with the stereolithographic SurgiGuide surgical template

Navigation technique

Chapter 3 The Edentulous Mandible

Diagnosis

3D CBCT diagnosis and SimPlant planning

3D diagnosis and SimPlant planning for the fabrication of the Sliwowski Overdenture System (SOS) SurgiGuide template

Note: Extremely narrow mandible

Rehabilitation with implant placement only in the interforaminal region

Removable prostheses on two implants

Typical treatment course

Removable immediate prosthesis on two implants and one prefabricated bar – the SOS method

Notes on the SOS method

Atypical treatment course – problematic baseline situation

Treatment of an extremely narrow residual ridge with the SOS method

SOS with osteoplasty and augmentation

Immediate implant placement following extraction and direct loading with SOS without a template

Problems and complications

Early loss of an SOS implant and re-implantation

Large mandibular defect and unexpected complication due to a slight change in position of the template

Note on impression taking

Removable prostheses on several implants

Typical treatment course

Immediate fixed bridge on five implants and definitive bar-retained restoration

Note: Connecting bar with a locking mechanism

Atypical treatment course – problematic baseline situation

Immediate loading with a provisional bar and an age-appropriate, definitive telescopic crown-retained prosthesis

Problems and complications

Inadequate dental prosthesis on two non-preservable implants – implant re-insertion and immediate loading

Fixed bridges on several implants

Typical treatment course

Fixed immediate bridge – implant placement with a 3D template

Atypical treatment course – problematic baseline situation

Extraction, immediate implant placement and immediate fixed bridge

Immediate fixed bridge loaded onto provisional implants

Problems and complications

Destruction of the residual ridge due to peri-implantitis

Removal of an incorrectly placed implant

Full rehabilitation including implant placement in the posterior mandible

Typical treatment course

Fixed bridges for prosthetic restoration of the entire mandible

Immediate mandibular prosthetic restoration loaded onto provisional implants

Atypical treatment course – problematic baseline situation

Fixed immediate prosthesis following extensive dental treatment and augmentation

Selective extractions for the optimal positioning of definitive implants

Problems and complications

Premature loosening of provisional implants

Iatrogenic complication during the removal of provisional implants and peri-implantitis after 10 years of functional use

Immediate loading of definitive implants

Immediate loading of permanent implants with a fixed bridge

Chapter 4 The Anterior Maxilla

Diagnosis with esthetic considerations

3D diagnosis and SimPlant planning

Single-tooth replacement

Typical treatment course

Single-tooth implant – Simpler in Practice technique

Note: Simpler in Practice Technique

Fabrication of the provisional restoration – Simpler in Practice

Esthetic requirements dictated by a high smile line

Atypical treatment course – problematic baseline situation

Single-tooth implants in an adolescent girl presenting with shortage of space

Note: Implants in adolescents

Emergency implant placement following traumatic loss of an anterior tooth

Problems and complications

Spontaneous perforation of the mucosa

Note: Fracture risk of ceramic abutments

Biological and mechanical complications: suture dehiscence and loosening of the screw retention

Development of an apical cyst at an anterior dental implant

Immediate loading of a single-tooth implant in the presence of a well-preserved residual ridge

Immediate implant placement and immediate loading following extraction of the primary canines

Immediate restoration of a single-tooth implant

Immediate implant placement following an inflammatory process around tooth

Premolar implants and several single-tooth implants

Premolar implant in a patient with a high smile line

Several single-tooth gaps following traumatic tooth loss

Restoration of several single-tooth gaps

Restoration of multi-tooth gaps

Typical treatment course

Replacement of four missing incisors on four implants

Replacement of four missing incisors on two implants

Atypical treatment course – problematic baseline situation

Restoration of a multi-tooth gap with preservation of the anatomical structures

Note: The “corkscrew technique”

Simultaneous immediate and delayed implant placement to replace two central incisors

Problems and complications

Implant treatment following the loss of an implant-supported restoration

Note: Mucosal graft technique

Immediate restoration loaded onto provisional implants following loss of the old implant-supported restoration

Chapter 5 The Posterior Maxilla

Diagnosis

Conventional diagnosis

Fabrication of a radiologic or surgical template

Note: Shaping the surgical template

3D diagnosis and planning

Restoration of single- and multi-tooth gaps

Typical treatment course

Fixed bridge with multiple abutments

Note: Cosine curve technique to improve the gingival situation

Atypical treatment course – problematic baseline situation

Restoration in a case of pronounced, one-sided residual ridge atrophy

Note: The cast coping laboratory method (relating to the case history on page 331)

Sinus floor elevation with vertical and horizontal augmentation and single-tooth implant with orthodontic treatment

Problems and complications

Sinus floor elevation with reconstruction of the residual ridge and gingiva

Implant treatment after sinus floor elevation in two sessions

Immediate loading

Immediate loading of a restoration on both provisional implants and natural teeth

Note: Aligning IPIs

Sinus floor elevation with horizontal augmentation, implant placement and immediate restoration loaded onto IPIs

Immediate restoration supported on definitive implants and one natural tooth

Free-end situation

Simple treatment course (without sinus floor elevation)

Restoration in the form of an abbreviated dental arch without sinus floor elevation

Implant placement without sinus floor elevation with a 3D template

Typical treatment course

Sinus floor elevation with lateral augmentation and mucosal distraction

Note: Sinus elevation (sinus floor elevation, sinus lift)

Implant placement with sinus floor elevation using the two-session approach

Atypical treatment course – problematic baseline situation

Implant placement with sinus floor elevation accompanied by concomitant apicoectomy and lateral bone augmentation

Extensive augmentation in several directions

Problems and complications

Sinus floor elevation involving avoidance of a blood vessel and perforation of the maxillary sinus mucosa

Apical granuloma on a smooth machined implant

Immediate loading

Immediate restoration with concomitant sinus floor elevation

Sinus floor elevation, implant placement and immediate restoration loaded onto IPIs

Chapter 6 The Edentulous Maxilla

3D diagnosis with a custom template

Note on the stabilization of the template

Rehabilitation without reconstruction of the posterior maxilla

Typical treatment course

Bar connector restoration on six implants

Note: Exposure technique

Cantilever implant bridge on nine implants

Atypical treatment course – problematic baseline situation

Removable restoration – incidental finding by CT imaging

Problems and complications

Fixed restoration with a change in implant inclination – a mechanical complication

Note: Mechanical complications

Immediate loading

Immediate loading of definitive implants with NobelGuide

Note: Immediate restoration on healing abutments

Rehabilitation with reconstruction of the posterior maxilla

Typical treatment course

Sinus floor elevation and implant placement in a single session

Severe residual ridge atrophy: sinus floor elevation and vertical augmentation prior to implant placement

Note: Several augmentative procedures in one operation

Atypical treatment course – problematic baseline situation

Extremely problematic baseline situation following the loss of sinus augmentation material and implants

Extreme residual ridge atrophy, sinus floor elevation with no bony sinus floor

Problems and complications

Severe horizontal residual ridge atrophy and loss of an implant

Sinus floor elevation and implant placement following loss of the old implants

Immediate loading

Typical treatment course

Immediate restoration of provisional implants following extraction

Immediate restoration with sinus floor elevation and implant placement

Atypical treatment course – problematic baseline situation

Sinus floor elevation and subsequent implant placement with immediate restoration loaded onto mixed implants

Sinus floor elevation with immediate restoration of provisional implants and no definitive implants

Problems and complications

Premature loss of provisional implants

Sinus floor elevation and immediate restoration loaded onto provisional implants, implant loss during the healing phase

Chapter 7 The Edentulous Maxilla and Mandible

Full rehabilitation of the maxilla and mandible

3D diagnosis

3D planning for implant placement in the maxilla and a Sliwowski Overdenture System (SOS) in the mandible

3D planning for sinus elevation in the maxilla and implant placement in the mandible

Typical treatment course

Bar structures with locking attachments in both maxilla and mandible

Sinus elevation and subsequent implant placement, reconstruction of the gingival zone

Note on split-thickness flaps and roll flaps

Atypical treatment course – problematic baseline situation

Sinus elevation, subsequent implant placement without immediate prosthetic loading

Switch from overdentures to implant-supported fixed restorations in both jaws

Problems and complications

Complication following an earlier treatment with disk implants in a heavy smoker with poor oral hygiene

Implant-supported restoration in a heavy smoker with poor oral hygiene

Immediate loading

Immediate restoration of provisional implants directly after dental treatment

Immediate restoration of provisional implants in the maxilla and definitive implants in the mandible, with a life-threatening complication

Notes on life-threatening hemorrhage

References

List of materials

The anterior mandible represents the most comfortable operating area for the implantologist. The main contributing factors for this include: good access and a good view of the operation site; a generally sufficient bone supply; no sensory anatomical structures; a lower risk of esthetic problems than in the maxilla; and less functional stress on the implants. For reasons such as these, this region is best suited for immediate non-functional or even immediate functional loading. However, the chief problem in this area is the smaller diameter of the mandibular incisors relative to standard implants. The replacement of one or two adjacent incisors presents a particular challenge.

3D diagnosis and planning

Pronounced residual ridge atrophy

Radiologic and dental cast analyses are two key components of the preoperative diagnostic investigations. In the standard panoramic radiograph, the visualization of the anatomical structures in the anterior tooth region often lacks sharpness, so that it needs to be supplemented with a single-tooth radiograph. Far more reliable planning can be achieved with the aid of either conventional computed tomography (CT) or cone beam CT imaging (CBCT), also known as digital volume tomography (DVT). Both methods provide a metrically exact representation of the region, free of any superimpositions, thus allowing precise three-dimensional (3D) planning.

A CBCT image provides not only a pictorial overview of the situation, but also enables very detailed planning. The 3D reconstruction gives the best overview. In the case presented here, tooth 41 is sited far from the residual ridge and hangs loosely in the soft tissue (Fig 1-1a). The bone defect that has developed appears correspondingly extensive, and it may be assumed that augmentation will be necessary. The gap following the loss of tooth 31 has closed completely, so that only one incisor can be replaced, even though both the middle ones are missing. The distance between the roots of the neighboring teeth is relatively big, so that sufficient space is available in the mesiodistal direction (Fig 1-1a). For detailed planning, the data are input into a planning program, in this instance SimPlant (Dentsply). In the SimPlant program, the intended implant can be taken from a library (collection of all current implant types) and placed in the jaw. An abutment can also be selected after the positioning of the implant, and placed onto it. In this case, the program allows a Brånemark System implant (Nobel Biocare), 18-mm long and with a diameter of 3.75 mm, to be selected based on the available bone supply. The implant abutment (in this case, CeraOne (Nobel Biocare), height 5 mm) can be seen in all three dimensions and in the 3D reconstruction (Fig 1-1b). The distance between the implant and the neighboring teeth is best assessed on the consecutive panoramic sections (Fig 1-1c). The most important view when planning each individual implant is the cross-sectional view, which shows the width of the residual ridge (Fig 1-1d). It allows the transverse and vertical bone supply to be assessed accurately, providing a basis for the prognosis of the primary stability of the implant. Any bone deficits that are present can be identified and a need for augmentation already becomes apparent in the planning phase. The 3D reconstruction provides a good overview of the available bone supply and the positioning of the implant (Fig 1-1e). Better assessment of the position of the implant relative to the nerve (which needs to be marked manually; Fig 1-1f) is delivered by the semi-transparent view or full fade-out of the bone structures. The model, with the section going through the implant, may be rotated in any direction, giving a view of the planned implant position from all perspectives (Fig 1-1g). The bone densitometry function provides good guidance on the expected bone quality at the implant site (Fig 1-1h). However, because of the poorer quality of the detailed visualization compared to CT, this analysis is of limited use when applied to CBCT images.

For the treatment course, see page 13.

Shortage of space, insufficient distance to the neighboring teeth

In this case, tooth 31 is not preservable due to painful internal resorption, and must therefore be extracted. This internal resorption has been confirmed on the CBCT images in all three planes. The width of the gap can be measured with high accuracy, not only radiologically, but also on the model after erasing tooth 31 (Fig 1-1i). The implant is planned using the SimPlant software (Fig 1-1j). One of the narrowest available implants, NobelDirect (Nobel Biocare), 16-mm long and with a diameter of 3 mm, has been selected due to the shortage of space. This implant is placed into the jaw virtually. The planning process is performed in all three planes and also with the aid of the 3D reconstruction. A visual representation of the positioned implant and its spatial relationship to the neighboring structures, particularly the teeth, becomes clearly apparent on the semi-transparent 3D reconstruction (Fig 1-1k). The panoramic section allows good assessment of the problem zones along the roots (Fig 1-1l).

It is advantageous to carry out an additional check of the spatial visualization on the horizontal (axial) section (Fig 1-1m). The most important evidence in most cases – the cross-sectional view – confirms that the dimensions of the residual ridge are adequate in this instance (Fig 1-1n).

For the treatment course, see page 16.

Single-tooth gap

The implant rehabilitation of a single-tooth gap in the anterior mandible, following the loss of one mandibular incisor, requires not only a special set of instruments, but also a particularly high level of precision from the implantologist. In most cases, the resultant gap is very narrow and the available space between the roots of the neighboring teeth extremely limited. Iatrogenic injury to the neighboring teeth can only be avoided with detailed preoperative radiologic investigations and by performing the surgical procedure with great care. If the residual ridge has healed, the freshly inserted implant can be loaded directly with a prosthesis, which is highly advantageous for both the patient and the dentist.

Because of the limited space, implants of reduced diameter, ie, narrow platform (NP) implants such as NobelActive (diameter 3.0 and 3.3 mm) and NobelDirect (diameter 3.0 mm) from Nobel Biocare, or Touareg (diameter 3.0 mm) from Adin or the K.S.I. Bauer screws, are particularly suitable for minimizing the risk of damage to the roots of neighboring teeth. Instruments required for implant placement include long shank drills, extra-long thread cutters and dental screwdrivers, as well as drill extensions, which can reach to the required depth in the narrow gap between the neighboring teeth (see page 16). Surgical guides or templates are used only in rare cases due to the limited space.

In the anterior tooth region, the single-tooth implant may be inserted directly after the tooth is extracted (immediate implant placement) or after the socket has fully healed (delayed implant placement). Requirements for immediate implant placement include: first, an adequate bone supply of good quality to anchor the implant with primary stability; and, second, the absence of any acute inflammation. After implant placement, the implant can be fitted with a cover screw and allowed to heal submerged, or with a healing abutment for transmucosal healing. In immediate implant placement, a healing abutment helps preserve the anatomical structures, such as the gingival margin and interdental papillae. Instead of a healing abutment, this function can also be performed by an interim crown on a provisional abutment, but these must be placed entirely out of both static and dynamic occlusion.

For the preoperative 3D investigations, see page 2.

3D analysis and SimPlant planning

A CBCT image was taken before implant placement and the implants were virtually positioned in the SimPlant program (Fig 1-2c). Because of the shortage of space and good bone quality, the plan was to use K.S.I. Bauer screws for both sites.

Attention: The advantage of K.S.I. Bauer screws is that they provide good primary stability and can be loaded immediately. They have been successfully used by the main author for many years as provisional implants for immediate loading. Despite earlier doubts, they are eminently suitable for use as definitive implants in extremely narrow gaps. They have a flexible section to allow the crown to be adjusted with regard to any prosthetic aspects.

Implant placement

Implant placement took place under general anesthesia and was performed in combination with the osteotomy of retained tooth 28 and bilateral sinus elevation. Before implant placement, the teeth located either side of the gaps were stripped slightly, to make more space for the crowns. The incision was made centrally over the residual ridge and extended further horizontally below papilla 41, 42 to provide a join. A labial flap was constructed, preserving the papilla, and both implants were inserted. The labial atrophy was treated with the harvested bone chips. Alignment of the implant heads was followed by tight closure of the incision with Gore-Tex (W. L. Gore and Associates) and Mopylen 6-0 sutures (Resorba) (Fig 1-2d). The first provisional crowns were manufactured and directly incorporated with the aid of theromoplastic foil. (Fig 1-2e).

Prosthetic loading

One week later, the sutures were removed and the long-term crowns fabricated in the laboratory were incorporated (Fig 1-2f). The labial contour of the residual ridge looks considerably better even after simple augmentation (Fig 1-2g). Implant placement into the maxilla following sinus elevation was planned for 1 year later. The new CBCT image also provided a view of the peri-implant bone in the mandible in all three planes (Fig 1-2h). Comparison of the planned implant 31 (Fig 1-2i) with the implant already in situ (Fig 1-2j) in a cross-sectional view showed slight deviation of the apex of the positioned implant in the labial direction. This has resulted from the considerable resistance offered by the hard lingual cortical bone. The inclination of the implant head (Fig 1-2j) could be corrected by bending it. After 1 year, the bone and gingival situation around the implants continued to be stable. The patient was so happy with the appearance and function of the provisional crowns that she did not even want to have the definitive crowns fitted (Fig 1-2k).

Extraction and implant placement

Extraction of the tooth and creation of a mucoperiosteal flap exposed an extensive bone defect, which had also led to exposure of one root surface of tooth 31 (Fig 1-3c). A regular platform (RP) implant (diameter 3.75 mm), 21-mm long and with a conical neck, was inserted centrally into this defect and the underlying residual ridge (Fig 1-3d).

Instead of a cover screw, a 2-mm-high healing abutment was screwed onto the implant to act as a spacer. The remaining crevices in the bone defect were filled with the bone chips harvested during preparation of the implant bed (Fig 1-3e). Saliva-proof wound closure was performed following periosteal slitting and mobilization of a trapezoid flap, using monofilament, microsurgical 6-0 sutures (Fig 1-3f). Use of a membrane was not necessary for this three-wall bone defect.

Attention: Implants of reduced diameter (NP, approximately 3 mm) are best suited for replacing a lower incisor. Only narrow implants allow an adequate distance to be maintained from neighboring teeth. At the time (in 1998), the longest NP implant in the Brånemark System was 15 mm long; stable anchoring in the bone was doubtful at this length. The extraordinary implant length of 21 mm is an enormous advantage where a deep defect is present: it ensures stable anchoring in basal bone, which is so important in immediate implant placement, thus resulting in sufficient primary stability.

Exposure and prosthetic loading

After a 5-month healing period, the implant was exposed and the healing abutment exchanged for a higher one (Fig 1-3g). At this point, the panoramic radiograph showed stable anchoring of the implant in the bone, along with good regeneration of the former bone defect (Fig 1-3h). The implant was fitted with a CeraOne abutment and prosthetically loaded with an all-ceramic crown. In view of the very small distance between the implant and neighboring tooth 31 (one disadvantage of an RP implant) and the lack of bone before implant placement (Fig 1-3d), it was not possible to create an interdental papilla. However, this caused no impairment to the patient, even with his widest smile (Figs 1-3i and 1-3j).

Extraction and implant placement

Once the tooth was removed, a wide mucoperiosteal flap was created between teeth 32 and 42 (Fig 1-5b). The gap was of sufficient width for a Nobel Biocare RP TiUnite implant (diameter 3.75 mm). The 18-mm long implant was inserted and a 5-mm-high CeraOne abutment was screwed on with the required torque of 32 N/cm. Augmentation was necessary to restore the contours of the residual ridge and cover the exposed implant threads (Fig 1-5c).

To encourage revascularization of the augmentation material, the labial cortical bone was perforated several times with a fine spiral bur (Fig 1-5d). The bone chips harvested during preparation of the implant bed were mixed with a regenerative bone substitute (Bio-Oss; Geistlich) and filled into the defect. A resorbable collagen membrane (Bio-Gide; Geistlich), fixed with small titanium pins, was used to stabilize the augmentation material (Fig 1-5e). The augmentation was overextended both horizontally and vertically to compensate for subsequent resorptive loss. Following saliva-proof suturing of the operation site, a provisional cap was fitted onto the CeraOne abutment (Fig 1-5f) and a provisional immediate crown with no functional loading prepared (Fig 1-5g).

Prosthetic loading

To achieve an optimal esthetic result when manufacturing the definitive crown, the CeraOne abutment, which was rather too long, should have been exchanged for an all-ceramic CerAdapt (Nobel Biocare) abutment (Fig 1-5h). However, the patient was happy to accept the metal rim that was only just visible, and did not want the abutment to be changed for financial reasons. Therefore, the definitive all-ceramic crown was incorporated on the existing abutment. Figure 1-5i shows the clinical situation 6 years following incorporation of the crown.

Extraction, immediate implant placement, augmentation and immediate loading

Due to the advanced internal resorption, the tooth fractured as soon as the dental forceps were applied. The remaining root was extracted using a periotome and a compression screw (Fig 1-6b) using the non-destructive “corkscrew technique” (see page 294), without damaging the bony socket. Following the non-destructive root extraction, a NobelDirect implant, 16-mm and with the smallest diameter (3 mm), was inserted into the socket (Fig 1-6c). The prepared provisional crown was cemented on with TempBond (Kerr Corporation) (Fig 1-6d).

Since part of the vestibular lamella could no longer be fully preserved, the small defect was augmented with the bone substitute OSTIM (Heraeus Kulzer) (hydroxylapatite; Fig 1-6e). The periosteal flap was repositioned without the use of a membrane and fixed with 6-0 sutures (Fig 1-6f). To ensure that implant healing was not endangered, the crown was placed completely out of occlusion (Fig 1-6g). The gingival situation (Fig 1-6h) stabilized after only a few weeks, and the implant was harmoniously incorporated into the overall situation (Fig 1-6i).

Multi-tooth gap

If several teeth have been lost from the anterior mandible, the level of difficulty of the implant treatment depends significantly on the width of the resultant gap. If three or four incisors have been lost, a functionally and esthetically satisfactory restoration can be achieved in most cases using two implants. A situation that presents a much greater therapeutic challenge is when two adjacent incisors have been lost and the gap is too wide for one implant, but too narrow for two. The insertion of a single implant and the subsequent reconstruction of both missing teeth is unfavorable both esthetically and functionally. If the restoration is to be accomplished with the aid of two implants, these should be as narrow as possible.

Implant placement

Implant placement was performed 6 weeks after extraction (Fig 1-7b). At this point, mobilization of the mucoperiosteal flap revealed that the extraction sockets had not yet healed (Fig 1-7c). Preparation of the implant bed in the regions of teeth 32 and 41 (Fig 1-7d) was followed by the insertion of two Replace Select implants (Nobel Biocare), 3.5 mm in diameter (Fig 1-7e). Vertical augmentation was necessary to enable the correct prosthetic positioning of the implants. Healing abutments 2 mm high were fitted instead of cover screws, to support the augmentation material (Fig 1-7f). The peri-implant bone defects were filled with the bone chips harvested during preparation (Fig 1-7g). The postoperative follow-up radiograph shows the positioning of the implants relative to the roots of the neighboring teeth (Fig 1-7h).