Graftless solutions for the edentulous patient

The need to wear a removable prosthesis or at times to abstain from wearing any form of dental prosthesis while the grafts were healing as well as the extended treat-ment times and the m

Graftless

Solutions for

the Edentulous Patient

Saj Jivraj

Editor

BDJ Clinician’s Guides

BDJ Clinician’s Guides

More information about this series at http://www.springer.com/series/15753

Saj Jivraj

Anacapa Dental Art Institute

Oxnard, California, USA

ISSN 2523-3327 ISSN 2523-3335 (electronic)

BDJ Clinician’s Guides

ISBN 978-3-319-65857-5 ISBN 978-3-319-65858-2 (eBook)

https://doi.org/10.1007/978-3-319-65858-2

Library of Congress Control Number: 2017964316

© Springer International Publishing AG 2018

This work is subject to copyright All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recita- tion, broadcasting, reproduction on microfilms or in any other physical way, and transmission or infor- mation storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed.

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The need to wear a removable prosthesis or at times to abstain from wearing any form of dental prosthesis while the grafts were healing as well as the extended treat-ment times and the multiple procedures needed prior to the placement of dental implants to support a fixed prosthesis deterred patients from seeking care.

Today, the “graftless concepts” eliminate the need for grafting and long waiting periods prior to the reconstruction of the edentulous or the patients with “terminal dentition” The ability to remove the patient’s failing dentition, place implants and fabricate a fixed, immediate load prosthesis has changed the manner in which many

of our colleagues treat their patients in 2017

The vast body of literature confirming that the graftless approach has the same or

at times better long-term outcome as compared to the 2-stage, delayed loading tocols has led to better patient care, higher patient acceptance of treatment while still maintaining long-term success data

pro-It is prudent at this point in time to consider why such a change in paradigm and treatment planning has occurred by reviewing the major research and development findings over the last several decades

In the 1980s, understanding bone biology and refining the surgical techniques for the preparation of the osteotomy and placement of the implant was the focus in research and development of implant dentistry We were content if osseointegration had occurred and referred the patient for prosthetic reconstruction of the implants regardless of the number, angulation or distribution of the implants

In the 1990s we began to understand the limits of functional loads placed on osseointegrated implants Attention to understanding the biomechanical limits of the hardware improved the management of the functional loads placed on implants resulting in more predictable, long-term outcomes

In the 2000s, research focused on “graftless concept” using tilted implants as well as distal site anchorage by using the Zygoma implant propelled treatment plan-ning to an unprecedented level The ability to treat a subgroup of patients declared

Foreword

• Patient-centred treatment planning

Congratulations to the editor, Dr Saj Jivraj, for his leadership in collaborating with experienced clinicians in producing this updated text for the treatment plan-ning of the edentulous patients with a fixed, implant-supported prosthesis

“…a decisive factor in patient care is simplification of treatment, which should

be based on identifying and utilizing the enormous capacity of existing original anchoring tissues…”

Simplification, understanding and appreciating when a treatment option is

ade-quate vs optimal

In conjunction with my colleagues Drs Zarrinkelk, Ferro and Yeung, we discuss treatment planning using conventional “analogue” techniques It is appropriate to highlight that the appreciation of “analogue” planning is critical and crucial if the clinician would like to transition using the digital workflow

Drs Pikos, Pozzi, Arcurrl and Moy comprehensively present the integration of digital treatment planning into the contemporary implant practice

Interdisciplinary management of every patient’s treatment plan resulting in a predictable outcome, which can only be achieved by following documented and

evidence-based treatment options

Drs Tunkiwala and Kher in collaboration with Mizuno and Torosian discuss the intricacies of the final prosthesis, which was envisioned in the treatment planning

stage They underscore the concept of “begin with the end in mind” in their

step-by-step discussions of the various stages for the fabrication of the planned definitive prosthesis

The ability to prevent as well as manage complications is essential for both the surgical and the restorative care provider Drs Bongard, Powel and Dawood discuss the various techniques and algorithms for the management of complications with the graftless concept

Long-term success in treatment planning for the fully edentulous patients is strongly linked to the ability to control the occlusal forces Our colleagues must recognize that recall appointments must be pragmatic Not only should the recall appointment address the patients oral hygiene but documenting the stability of the abutment and the prosthetic screws is absolutely critical

“…the continuous cross arch rigid connection of the prosthesis to the implants

by ensuring tight abutment and prosthetic screws is essential for long term success…”.

Foreword

In the immortal words of PI Branemark,

“Listening to the needs and the demands of the patient and executing treatment

plans in the best interest of our patients is paramount.”

Foreword

Dental implants are one of the most significant developments in the treatment of patients who are missing teeth When the method to place and restore these implants was presented to North America at the Toronto Conference more than 30 years ago,

a strict protocol was adhered to

Over time, researchers and clinicians have taken advantage of better imaging, CAD/CAM technology, newer materials and implant designs to innovate and develop methods of shortening treatment times while obtaining predictable out-comes for patients

These methods and materials have been used and reported on by multiple authors and some of these authors have collaborated on this book Collectively they have contributed to this particular method of restoring edentulous patients and elucidated not only the mechanics of placing and restoring implants but more importantly man-aging atypical situations, patient selection and management of complications.Readers of this book will clearly understand a clear treatment protocol that will lead to predictable outcomes for their patients In addition this body of work can help clinicians decide on whether this mode of treatment is suitable for their patients and help them to avoid any complications that may occur This information will also allow the clinician to decide when it is appropriate to refer a patient to more experi-enced colleagues

I have known Dr Jivraj personally for over 15 years and can attest to his tion to patient care and using a solid evidence base to make treatment decisions Rest assured he has taken the same care in assembling this experienced group of clinicians and teachers to share their experiences and knowledge on this focused subject

dedica-Winston Chee, D.D.S., F.A.C.P University of Southern California

Los Angeles, CA, USA

Foreword

Dr Saj Jivraj has assembled in this textbook a quintessential team of talented renown surgeons and restorative dentists who extensively share their vast knowl-edge in the latest innovations in Implant Dentistry In order to address the ever-increasing magnitude of patients in need of extensive implant treatment, graft-less implant solutions must be combined with an in-depth knowledge of surgical and restorative procedures through a rigorous and well-coordinated interdisciplin-ary approach

world-This textbook displays in an effective and methodical manner the modern dation for the diagnosis and graftless treatment of edentulous patients with fixed implant-supported prosthetics It provides clear and understandable concepts through basic and advanced implant principles that are required in the initial com-prehensive diagnosis and digital workflow all the way through the interdisciplinary teamwork necessary to manage tilted and zygomatic implants, and ultimately pro-duce high-quality full arch implant supported restorations

foun-We have greatly benefited over the past years at Augusta University from the great teachings of Dr Jivraj and we trust that this important work will be enjoyed worldwide as a reference textbook in modern implant dentistry

Gerard J. Chiche The Dental College of Georgia

Augusta, GA, USA

Foreword

As the years pass, the things that become important really come into perspective It

is to these important aspects of my life that I wish to dedicate this book

To My Family

First and foremost and without hesitation I would like to thank my beautiful wife Dilaz She is my life, my inspiration and a wonderful mother to my two beautiful children Sara and Zain You said “yes” to everything which should have been “no”; you allowed me the time to become professionally what I dreamed about as a young graduate You persevered when times got tough and gave up everything moving with

me to the USA. For the countless hours I did not spend with you and the kids, for the unconditional love, friendship and unwavering support I thank you To Sara and Zain, words cannot express the profound love I have for you You have taught me to appreciate life in ways I thought were not possible, the little things you do and say make me a better person, husband and father I will always be by your side to sup-port you in anything you do Work hard and dream big and believe in the impossible

I would also like to dedicate this book to the memory of two exceptional women, Mrs Amina and Rukiya Jivraj, who were taken from this world far too early Not a day goes by when I don’t think of you I feel your presence in all the important deci-sions that I make I miss you both dearly and wish we could have created more memories together When people say, “Life is too short”, I now understand what that means I do know we will meet again, and it is that day to which I look forward

To My Colleagues

I’d like to thank Drs Winston Chee and Terry Donovan who believed in me and who provided me with the opportunity to complete my Prosthodontic education at the Herman Ostrow USC School of Dentistry I will be forever grateful

This journey began with Dr Hooman Zarrinkelk over a decade ago I would like

to thank him for taking the road less travelled with me He has pushed me to be the best I can be I admire his attention to detail and commitment to excellence A lot of the patients you see in this text are the result of our collaboration There are very few

in our profession like him and I am grateful for having had the opportunity to work with him and to see a professional relationship turn into a lifelong friendship

Acknowledgements

Dr Armando Lopes and Dr Paulo Malo for their contributions to the text.

The laboratory section was graciously written by Mr Kenji Mizuno and Mr Aram Torosian I truly appreciate the countless hours they spent documenting the lab phase and putting it into a format that is practical

I would like to acknowledge all the students and faculty involved with the advanced Prosthodontic programme at Herman Ostrow USC School of Dentistry from whom I have learnt so much and still continue to do so

I would be remiss if I did not thank my team at Anacapa Dental Art Institute They make coming into work each day enjoyable and always go the extra mile for our patients Their dedication and commitment is second to none and I want to let you know I appreciate everything you do

I would also like to thank Melker Nielsson for his friendship and advice over the years It was through his guidance and support that I pursued graftless solutions as

an option for my patients

To My Patients

Who make each and every day enjoyable for me Thank you for allowing me to compile these clinical photographs It’s caring for these patients that makes my profession so rewarding and makes me look forward to the next day

Contents

1 Diagnosis and Treatment Planning: A Restorative Perspective 1

Saj Jivraj and Hooman Zarrinkelk

2 Diagnosis and Treatment Planning: A Surgical Perspective 15

Hooman M Zarrinkelk and Saj Jivraj

3 Guided Surgery: Treatment Planning and Technique 25

Mike A Pikos and Saj Jivraj

4 Comprehensive Integrated Digital Workflow

to Guide Surgery and Prosthetics for Full-Arch

Rehabilitation: A Narrative Review 45

Alessandro Pozzi, Lorenzi Arcuri, and Peter Moy

5 Surgical and Prosthetic Biomechanical Considerations

When Using the Zygoma Implant 69

Edmond Bedrossian, Edmond Armand Bedrossian, Spencer

Anderson, and Chan Park

6 Scientific Basis of Immediate Loading and the Biomechanics

of Graft-Less Solutions 85

Bobby Birdi, Saj Jivraj, and Komal Majumdar

7 Graftless Surgical Protocol 99

Ana Ferro, João Botto, Mariana Alves, Armando Lopes, and Paulo

Maló

8 Surgical Protocol for the Placement of the Zygomatic Implant:

A Graftless Approach for Treatment of the Edentulous Maxilla 133

Edmond Bedrossian and Per-Ingvar Brånemark

9 Rationale for Immediate Loading 159

Stephanie Yeung and Saj Jivraj

10 Material Considerations for Full-Arch

Implant-Supported Restorations 189

Saj Jivraj and Sundeep Rawal

11 Clinical Steps for Fabrication of a Full- Arch Implant-Supported

Restoration: Metal Ceramics, Zirconia, Acrylic Titanium 213

Udatta Kher, Ali Tunkiwala, Saj Jivraj, and Aqeel Reshamvala

12 Speech and Facial Aesthetic Considerations for the Contour

of Fixed Prostheses 243

Glen Liddelow and Graham Carmichael

13 Laboratory Fabrication of Full-Arch

Implant-Supported Restorations 261

Kenji Mizuno, Aram Torosian, and Saj Jivraj

14 Prosthetic Complications with Immediately Loaded,

Full-Arch, Fixed Implant-Supported Prostheses 321

Steven Bongard and David Powell

15 Management of Failure and Implant- Related Complications

in Graftless Implant Reconstructions (for Atrophic Jaws) 333

Andrew Dawood and Susan Tanner

16 Maintenance of Full-Arch Implant- Supported Restorations,

Peri-implant and Prosthetic Considerations 355

Sanda Moldovan and Saj Jivraj

17 Clinical Patient Presentations 367

Saj Jivraj and Hooman Zarrinkelk

Index 429

Contents

Lorenzi Arcuri University of Rome Tor Vergata, Rome, Italy

Edmond  Bedrossian American Board of Oral & Maxillofacial Surgery, Chicago, IL, USA

Department of Oral & Maxillofacial Surgery, University of the Pacific Arthur

A. Dugoni School of Dentistry, San Francisco, CA, USA

Implant Surgical Training, University of the Pacific Arthur A.  Dugoni School of Dentistry, San Francisco, CA, USA

American College of Prosthodontics, San Francisco, CA, USA

Bobby  Birdi, M.D., M.Sc., F.R.C.D.(C) University of Minnesota School of Dentistry, Minneapolis, MN, USA

Private Practice, Vancouver, Canada

João  Botto, D.D.S., M.Sc. Oral Surgery Department, Malo Clinic, Lisbon, Portugal

Per-Ingvar  Brånemark, M.D. The Brånemark Osseointegration Center (BOC), Gothenburg, Sweden

Graham Carmichael, BSc, BDSc Hons, DClinDent Consultant Prosthodontist, Craniofacial Unit, Princess Margaret Hospital, WA, Australia

Consultant Prosthodontist, Maxillofacial Department, Royal Perth Hospital, Perth,

The Dawood and Tanner Specialist Dental Practice, London, UK

Edmond  Armand  Bedrossian Department of Prosthodontics, University of Washington, Seattle, WA, USA

Ana Ferro, D.D.S., M.Sc. Oral Surgery Department, Malo Clinic, Lisbon, Portugal

Saj  Jivraj, B.D.S., M.S.Ed. Herman Ostrow USC School of Dentistry, Los Angeles, CA, USA

Eastmann Dental Institute, London, UK

Private Practice, Oxnard, CA, USA

Udatta Kher, M.D.S. Private Practice, Mumbai, India

Glen Liddelow, BDSc, MScD, DClinDent Clinical Associate Professor, School

of Dentistry, University of Western Australia, Perth, WA, Australia

Consultant Prosthodontist, Craniofacial Unit, Princess Margaret Hospital, WA, Australia

Armando  Lopes, D.D.S., M.Sc. Oral Surgery Department, Malo Clinic, Lisbon, Portugal

Komal Majumdar, B.D.S., D.I.C.O.I., D.I.S.O.I. Diplomate of the International Congress of Oral Implantologists, Indian Society of Oral Implantologists, Mumbai, India

Paulo  Maló, D.D.S., Ph.D. Oral Surgery Department, Malo Clinic, Lisbon, Portugal

Kenji Mizuno, C.D.T. Oxnard, CA, USA

Sanda Moldovan, D.D.S., M.S., C.N.S. Private Practice, Beverly Hills, CA, USA

Peter Moy, D.M.D. Oral and Maxillofacial Surgery, Restorative Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA

Surgical Implant Dentistry, Los Angeles, CA, USA

Chan Park, D.D.S., M.D. Department of Oral & Maxillofacial Surgery, University

of the Pacific, Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA

Mike A. Pikos, D.D.S. Private Practice, FL, USA

David Powell, D.M.D., M.Sc., FR.C.D.(C) Chrysalis Dental Centres, North York,

Sundeep Rawal, D.M.D. Private Practice, FL, USA

Aqeel  Reshamvala, B.D.S., M.D.Sc. Dept of Prosthodontics, MGM Dental College and Hospital, Navi Mumbai, India

Steven Bongard, D.D.S. Chrysalis Dental Centres, North York, ON, Canada

Susan Tanner, M.R.D., R.C.S.(Eng.), M.Sc. The Dawood and Tanner Specialist Dental Practice, London, UK

Aram Torosian, C.D.T., M.D.C. A.S. Ronald Goldstein Center for Esthetic and Implant Dentistry, Dental College of Georgia at Augusta University, Georgia

Ali Tunkiwala, M.D.S. Private Practice, Mumbai, India

Stephanie Yeung, D.D.S. Private practice, Santa Monica, USA

Hooman Zarrinkelk, D.D.S. Diplomate, American Board of Oral and Maxillofacial Surgeons, Chicago, IL, USA

Fellow, American College of Oral and Maxillofacial Surgeons, Washington,

DC, USA

Private Practice, Ventura, CA, USA

Contributors

© Springer International Publishing AG 2018

S Jivraj (ed.), Graftless Solutions for the Edentulous Patient, BDJ Clinician’s

Guides, https://doi.org/10.1007/978-3-319-65858-2_1

S Jivraj, B.D.S., MS.Ed ( * )

Herman Ostrow USC School of Dentistry, Los Angeles, CA, USA

Eastmann Dental Institute, London, UK

Private Practice, Oxnard, CA, USA

e-mail: saj.jivraj@gmail.com

H Zarrinkelk, D.D.S

Diplomate, American Board of Oral and Maxillofacial Surgeons, Chicago, IL, USA

Fellow, American College of Oral and Maxillofacial Surgeons, Washington, DC, USA

Private Practice, Ventura, CA, USA

pres-to aesthetics, phonetics, form and function are high

There are a myriad of factors that need to be evaluated to determine if the patient is a suitable candidate for a fixed vs a removable implant-supported res-toration Evaluation of the edentulous patient is also complicated by the fact that patients may not only be missing clinical crown height but in addition may have experienced a combination of tooth, soft tissue and bone loss, with associated changes in facial form

The purpose of this chapter is to evaluate the diagnostic factors that are cal in treatment planning of a patient for fixed implant-supported restorations

criti-The predictability of successful osseointegrated implant rehabilitation of the tulous jaw as described by Branemark et al [1] introduced a new era of manage-ment for the edentulous predicament

Implant rehabilitation of the edentulous patient remains one of the most complex restorative challenges because of the number of variables that affect both the aes-thetic and functional aspects of the prosthesis

The routine treatment for edentulism has been complete dentures Epidemiological data has reported that the adult population in need of 1 or 2 dentures would increase from 35.4 million adults in 2000 to 37.0 million adults in 2020 [2], and the research-ers warn that their estimates may be “significantly conservative” Clinical studies have reported that patients with dentures have shown only a marginal improvement

in the quality of life when compared with implant therapy [3] The common reasons for dissatisfaction in patients using dentures include but are not limited to pain, poor retention and stability and difficulty eating [4]

A review of the literature noted that prostheses supported by osseointegrated implants significantly improved the life of edentulous patients when compared with conventional dentures [5]

Many patients tolerate complete dentures despite the dissatisfaction

Reasons for this could be the following:

• Anatomic: They have been told that they are not implant candidates because of pneumatized sinuses and severe resorption of the posterior mandible

Due to economic factors, many patients have been provided with implant- and mucosa-supported overdentures

However, cost needs to be considered not only during fabrication of the sis but also during maintenance Overdentures seem to have more post-insertion maintenance than their fixed counterparts If this is consistent, it could be ques-tioned whether an economic indication for choosing an overdenture could be justi-fied when there is sufficient bone to support implants for a fixed prosthesis The patient must be made aware that maintenance costs for removable prostheses on implants will be higher than those of a fixed prosthesis Today, clinicians are seeing

prosthe-an increasing number of dentate patients where the dentition is terminal These patients would have been edentulous a long time ago if it had not been for the efforts of skilled restorative dentists Clinical treatments have involved maintain-ing non- restorable teeth for as long as possible to avoid a removable appliance Patients understand that maintaining a terminal dentition has consequences on the bone However, the fear of edentulism forces them to ignore failing oral conditions

In spite of the increasing numbers of edentulous or soon-to-be edentulous patients, there still appear to be many reasons why patients avoid treatment with dental implants

S Jivraj and H Zarrinkelk

These reasons could include the following:

• The fear of wearing a removable appliance in the transitional phase

• The notion that the proposed treatment is time consuming and unpredictable

• The number of visits involved and the fear of pain

• Cost

Most patients will look toward an implant rehabilitation hoping to acquire a fixed prosthesis Treatment planning of edentulous patients with fixed restorations on dental implants has undergone a paradigm shift since the introduction of graft-less solutions, in particular the All-on-4 method™

Today, patients have options whereby in the right indication complete tion can be accomplished by the use of four implants per arch The major advan-tages of this procedure are reduced number of implants and ability to bypass extensive grafting procedures This rehabilitation not only satisfies aesthetics and function but also considerably reduces costs for the patient This ultimately results

rehabilita-in rehabilita-increased patient acceptance and an rehabilita-increased number of patients treated Very few patients today are able to afford extensive implant rehabilitations on six to eight implants and the All-on-4™ or graft-less protocol is gaining popularity as being the treatment of choice for the edentulous patient

In a world environment where the numbers of edentulous patients are increasing, there are not enough available dentists trained in these protocols to be able to treat them Patients are not given these options because of the dentist’s reluctance to offer them Reasons for this are lack of education and the notion that these treatment protocols are not predictable despite there being numerous multicentre studies to the contrary

As in all phases of dentistry, diagnosis is critical in obtaining a predictable come An incomplete or erroneous diagnosis can yield unsatisfactory results for both the patient and treating clinician

out-The decision-making parameters when rehabilitating patients require the clinician

to make a decision as to whether a fixed or a removable prosthesis would be more suitable Zitzmann and Marinello [6] and Jivraj et al [7] described in detail parame-ters that need to be evaluated A fixed restoration should not be promised to a patient until all diagnostic criteria are evaluated These criteria must include quality and quan-tity of bone available to support implants, lip line, lip support and aesthetic demands Implants should not be placed until a definitive treatment plan has been established as implant positions may vary depending on the type of prostheses to be delivered.From a diagnostic perspective, several parameters need to be evaluated before deciding upon the type of prosthesis that is most appropriate for the patient The following considerations pertain to restorative treatment planning (Fig. 1.1) Surgical considerations will be presented in a separate chapter:

1 Positioning of the maxillary and mandibular incisal edge

2 Restorative space

3 Lip support

1 Diagnosis and Treatment Planning: A Restorative Perspective

4 Smile line and lip length

5 Contours and emergence

aesthet-to determine if adequate space exists for the anticipated resaesthet-toration Often the illary incisal edge is overerupted and treatment planning involves repositioning the incisal edge more apically (Fig. 1.2) Putting the maxillary central in the right posi-tion may require alveolectomy to provide sufficient running room from the head of the implant fixture to the emergence profile as it exits the free gingival margin [9]

max-To determine if a fixed or removable restoration would be appropriate, a wax

in is done without a flange For a fixed restoration, the clinical crown should ideally end up at the soft-tissue level of the alveolar ridge In this situation, minimal resorp-tion would have occurred, interarch space will be favourable and an optimal tooth- lip relationship is present When a large vertical distance exists between the cervical

Upper lip length Facial and lip support Smile line

Phonetics

Amount of bone available

Position of incisal edge

Thickness

of mucosa

Intra-oral factors Extra-oral factors

Fig 1.1 Factors that need consideration before deciding upon a fixed vs removable implant

rehabilitation

S Jivraj and H Zarrinkelk

aspect of the tooth and the alveolar ridge but the tooth-lip relationship is favourable, pink ceramic or acrylic may be utilized to disguise the tooth length and a fixed res-toration is still possible When there is both a vertical and horizontal discrepancy between the ideal position of the tooth and the alveolar ridge, and the tooth-lip relationship is not optimal, this may be an indication for use of a removable prosthe-sis The flange will provide adequate lip support, and the teeth can be positioned appropriately to satisfy the parameters of aesthetics

The mandibular incisal edge is positioned for function The clinician must vide shallow guidance, sufficient to provide posterior disclusion in both protrusive and lateral excursions Anterior guidance must be smooth and distributed amongst

pro-as many anterior teeth pro-as possible

A thorough evaluation must be made of the existing mandibular incisal-edge position When patients are missing posterior teeth and have been diagnosed as hav-ing lack of posterior support the mandibular incisal edge is often in the incorrect position The clinician must decide whether to reshape, reposition or restore if the maxillary arch is being considered for implant-supported restorations Conventional prosthodontic guidelines will place the mandibular incisal edge just at the level of the lower lip with 0.5–1.0 mm of the incisal edge visible Guidelines in relation to the lower mandibular occlusal plane can also be sought from anatomical landmarks such as the retromolar pad

If the clinician is planning a fixed implant-supported restoration for the ble, adequate restorative space must be provided The overeruption of teeth brings with it an excess of bone, which must be reduced prior to the implants being placed

differ-Fig 1.2 Repositioning the incisal edge more apically will have an impact on the implant

place-ment Alveolectomy will need to be performed prior to implant placement in this patient’s case

1 Diagnosis and Treatment Planning: A Restorative Perspective

space.14 Adequate restorative space is critical, and guidelines exist depending upon the type of prosthesis in the treatment being planned There must be adequate space for bulk of restorative material that also permits a prosthesis design to estab-lish aesthetics and hygiene If space is limited, re-establishing a patient’s vertical dimension or altering the opposing occlusion should be considered [10]

Guidelines for space requirements for ceramic-based restorations are 10–13 mm for a screw-retained ceramic-based restorations and 14–16  mm for acrylic resin/titanium-based restorations (Figs. 1.3 and 1.4) [6 7]

1.3 Lip Support

One of the best diagnostic tools is the patient’s existing maxillary denture The cian can evaluate the patient’s denture to determine what are the likes and dislikes regarding aesthetics, speech and function Each point should be noted for improve-ments in the new restoration There is always a tendency for patients to prefer fixed over removable prostheses It is the restorative dentists’ responsibility to determine

clini-if this is feasible Facial support is an important decision in this regard

Assessment of the patient’s facial support with and without the denture in place, with the patient facing forward and in profile, needs to be made so the clinician can determine which type of prostheses would be more suitable (Figs. 1.5 and 1.6)

Facial support, if inadequate, is obtained mainly by the buccal flange of a removable restoration Lip support is derived from the alveolar ridge shape and cervical crown contours of the anterior teeth Resorption of the edentulous maxilla proceeds cranially and medially and this often results in a retruded position of the anterior maxilla.When evaluating a diagnostic set-up with the anterior teeth in proper relation to the lip, the position of the anterior teeth is often anterior to the alveolar ridge (Figs. 1.7 and

1.8) Depending on the severity of the resorption, there can be a discrepancy between the ideal location of the teeth and the ridge This, in turn, leads to a discrepancy of the anticipated position of the implants in relation to the teeth This discrepancy must be taken into consideration to achieve a prosthesis that satisfies the parameters of adequate speech, lip support, hygiene, sufficient tongue space and patient acceptance

If the anticipated position of the teeth and implant results in a large horizontal crepancy, a number of options must be considered before finalizing implant placement

dis-If the horizontal discrepancy is quite large, options include the following: (a) Bone reduction and a deeper implant placement to allow the contours of the restoration to satisfy the parameters of lip support and hygiene: Without bone reduction, undesirable contours in the restoration are developed, which make it very difficult for the patient to maintain hygiene (Fig. 1.9)

Fig 1.5 Looking at the profile view of the patient with the denture in and out can give the

clini-cian an indication if the flange of the denture is required for lip support

Fig 1.6 This patient has an obvious lack of lip support with a concave facial profile

1 Diagnosis and Treatment Planning: A Restorative Perspective

Fig 1.8 Patient with flangeless try-in This patient is a candidate for a fixed implant-supported

restoration

Fig 1.9 If a patient with inadequate lip support requests a fixed restoration the clinician must

assess to see if this is possible On occasion bone must be removed and the implant placed higher

up so the emergence of the restoration can start higher up

Fig 1.7 When requesting a diagnostic denture set-up from a dental technician, a flangeless try-in

should be requested

S Jivraj and H Zarrinkelk

(b) LeFort I osteotomy: Most patients are reluctant to undergo this type of surgery

(c) Use of a removable flange and fabrication of an implant-supported overdenture

1.4 Smile Line and Lip Length

The movement of the upper lip during speech and smiling should be evaluated Tjan

et al [8] described the average smile as having the position of the upper lip such that 75–100% of the maxillary incisors and interproximal gingival are displayed In a high smile line, additional gingival is exposed, and in a low smile line, less than 75% of the maxillary anterior teeth are displayed Lip length should also be evalu-ated because it influences the position of the maxillary anterior teeth In a patient with a short upper lip, the maxillary anterior teeth will be exposed in repose (Fig. 1.10), whereas in patients with a long upper lip, the anterior teeth will usually

be covered

Dentate patients with a terminal dentition may present with excessive gingival display Causes of excessive gingival display include but are not limited to

1 Vertical maxillary excess

2 Short upper lip

3 Hyperactive upper lip

treat-Edentulous should be asked to smile with and without the denture in place (Figs. 1.11

and 1.12) If the soft tissue of the edentulous ridge cannot be seen, the transition between an implant-supported prosthesis and the residual ridge crest will not be visi-ble, resulting in flexibility for colour matching and the contour change of the prosthesis

Fig 1.10 A short lip poses a challenge The transition zone may be visible

1 Diagnosis and Treatment Planning: A Restorative Perspective

at the junction of the soft tissue If the alveolar ridge crest is displayed during smiling, the aesthetics can be very challenging because the junction between the restoration and the gingival complex will be visible and bear aesthetic consequences If the patient has minimal resorption, conventional metal ceramic restorations or zirconia-based restora-tions supported by implants can be planned and the existing soft tissue can be devel-oped to enhance aesthetics However, if an implant- supported denture (hybrid/profile prosthesis) is being planned, the alveolar ridge display will detract from the aesthetics

In situations like this, alveolectomy as part of a proactive protocol must be considered prior to implant placement If alveolectomy is not performed, the restorative outcome will display the transition zone, which, ultimately, is very difficult to retreat Alveolectomy must only be performed when there is an indication for it and the mini-mum amount of bone must be removed to satisfy the clinical objectives

1.5 Contours and Emergence

The contours of the restorations have to be planned from the outset The emergence profile of the restorations should be straight as it exits from the gingival margin Often this requires alveolectomy to create sufficient space The restorative dentist requires this space to develop adequate mechanics, aesthetics and cleansability This space

Fig 1.11 For an edentulous patient, the denture is removed and the patient asked to smile without

the denture in place; the ridge should not be visible

Fig 1.12 If the ridge is visible, alveolectomy may be necessary to hide the transition zone,

depending upon the type of restoration to be fabricated

S Jivraj and H Zarrinkelk

creation must be communicated to the surgeon through the use of a bone reduction guide and it becomes the surgeon’s responsibility to provide this space [12] One misconception about graft-less protocols is that they always require a significant amount of bone reduction Bone reduction has to have a rationale and the minimum bone reduction must be done to satisfy the requirements of implant placement and fabrication of a biomechanically sound restoration [13]

Rationales for bone reduction include but are not limited to

1 Adequate buccolingual width of bone to place implants

2 Adequate space for hygiene

3 Adequate space for biomechanics of the restoration

4 Adequate space so that the patient can clean the undersurface

5 Hide transition zone

6 Improve emergence of the restoration (Figs. 1.13 and 1.14)

1.6 Appropriate Tissue Contact

As in any aspect of restorative dentistry, the provisional is key to the success of the definitive restoration From a patient perspective the communication of aesthetics and phonetics is important From a clinician’s perspective, biomechanics, occlusion

Hide transition zone

Fig 1.13 Haphazard bone reduction need not be done; there has to be a specific reason for

alveolectomy

Fig 1.14 A bone reduction guide must be stable and have a reference point from which the

sur-geon can measure

1 Diagnosis and Treatment Planning: A Restorative Perspective

and cleansability are key areas of concern The original hybrid prostheses were designed to provide a “high water” design This was done predominantly to facili-tate oral hygiene Today patients often complain of food entrapment with these types of designs The provisional/immediate load prosthesis must satisfy the follow-ing criteria:

(a) Reduces food entrapment: Following 3  months of healing the acrylic sional should be relined so that it compresses the tissue surface and creates a concave tissue surface allowing a convex restoration surface

(b) Provides cleansable contours by developing the tissue as outlined above (c) Eliminates speech impairment: The t and d sounds relate to the palatal aspects

of the maxillary prosthesis and this area can be adjusted to accommodate for that The “S” sound is developed utilizing the closest speaking space and this should also be corrected in the provisional prior to proceeding to the definitive restoration

(d) The tissue contact should be intimate, but accessible to oral hygiene procedures

(e) The tissue surface should be highly polished

1.7 Occlusion

Occlusion in this chapter pertains to the occlusion on the immediate load sional restoration Occlusion for the definitive prosthesis will be addressed in a sub-sequent chapter In regard to occlusion there are no literature references citing the superiority of one occlusal scheme over another, one tooth form over another and patients’ preference of one occlusal scheme to another Unfortunately there are no randomized controlled clinical trials guiding the clinician to develop the occlusal scheme on the immediate load provisional prosthesis Most occlusal schemes are based on biomechanics and distribution of the occlusal forces over areas which are most likely able to tolerate them (Figs. 1.15, 1.16, and 1.17)

provi-Fig 1.15 The undersurface of the immediate load provisional restorations must be convex and

highly polished

S Jivraj and H Zarrinkelk

Clinical guidelines for developing occlusion include but are not limited to [14–17]

(a) Good AP spread of implants

(b) Minimum vertical overlap

(c) Bilateral simultaneous contact

(d) No interferences in lateral excursion

(e) Cross-arch stabilization with a passive screw-retained acrylic prosthesis which has sufficient rigidity to withstand occlusal forces without breaking

(f) No cantilevers

(g) Occlusal contacts from canine to canine only with shimstock drag on the rior teeth The rationale for this approach is centred around bone quality and occlusal forces The posterior implants are in the weakest bone quality The occlusal forces are highest the further we go back in the mouth The rationale is

poste-to protect the implants in the weakest quality bone being subjected poste-to the est occlusal forces If this requires developing a ramp on the palatal aspect of the anterior teeth this should be completed with cold-cured acrylic resin If the patient has a severe class two incisor relationship the above will not be possible

high-in which case occlusal contacts are evenly distributed around the arch

Fig 1.16 The provisional restoration must be used to shape the tissue over time When the

clini-cian makes an impression the tissue surface should be concave so the restoration surface can be convex

Fig 1.17 Force distribution requirements of the immediate load transitional restoration

1 Diagnosis and Treatment Planning: A Restorative Perspective

Achieving successful outcomes with graft-less solutions is significantly more challenging than with conventional restorations Diagnosis and appropriate treat-ment planning are critical in obtaining a successful outcome Implant concepts have undergone a significant evolution, not only in terms of designs, materials and sur-faces but also in terms of clinical and technical management Clearer understanding

of both the surgical and restorative protocols enables the clinician to better plan the outcomes of implant therapy

References

1 Branemark PI, Hansson BO, Adell R, Breine U, Lindstrom J, Hallen O, et al Osseointegrated implants in the treatment of the edentulous jaw Experience from a 10-year period Scand J Plast Reconstr Surg Suppl 1977;16:1–132.

2 US Bureau of the Census Statistical abstract of the United States: 1996 116th ed Washington DC: US Bureau of the Census; 1996 p. 15, tables II, No 16, p 17,table II, No 17.

3 Allen PF, McMillan AS. A review of the functional and psychosocial outcomes of ness treated with complete replacement dentures J Can Dent Assoc 2003;69(10):662.

4 Heath MR. The effect of maximum biting force and bone loss upon masticatory function and dietary selection of the elderly Int Dent J 1982;32:345–56.

5 Turkyilmaz I, Company AM, McGlumphy EA. Should edentulous patients be constrained to removable complete dentures? The use of dental implants to improve the quality of life for edentulous patients Gerodontology 2010;27(1):3–10.

6 Zitzmann NU, Marinello CP. Treatment plan for restoring the edentulous maxilla with implant supported restorations: removable overdenture versus fixed partial denture design J Prosthet Dent 1999;82(2):188–96.

7 Jivraj S, Chee W, Corrado P.  Treatment planning of the edentulous maxilla Br Dent J 2006;201(5):261–79.

8 Tjan AH, Miller GD, The JG. Some aesthetic factors in asmile J Prosthet Dent 1984;51:24–8.

9 Schwarz MS, Rothman SL, Rhodes ML, Chafetz N.  Computed tomography: Part II.  Pre- operative assessment of the maxilla for endosseous implant surgery Int J Oral Maxillofac Implants 1987;2:143–8.

10 Wicks RA. A systematic approach to definitive planning for osseointegrated implant ses J Prosth 1994;3(4):237–42.

11 Robins JW. Differential diagnosis and treatment of excess gingival display Pract Periodontics Aesthet Dent 1999;11(2):265–72.

12 Bedrossian E. Implant treatment planning for the edentulous patient St Louis: Mosby Elsevier; 2008.

13 Balshi TJ, Wolfinger GJ, Balshi SF. Analysis of 356 pterygomaxillary implants in edentulous arches for fixed prosthesis anchorage Int J Oral Maxillofac Implants 1999;14(3):398–406 prosthodontics JPD 1976 Dec;36(6):624-635

14 Schnitman PA, Wohrle PS, Rubenstein JE, DaSilva JD, Wang NH.  Ten-year results for Branemark implants immediately loaded with fixed prostheses at implant placement Int J Oral Maxillofac Implants 1997;12:495–503.

15 Brunski JB.  Biomechanical considerations in dental implant design Int J Oral Implantol 1988;5(1):31–4.

16 Malo P, Rangert B, Nobre M “All on 4”, immediate function concept with Branemark implants for completely edentulous mandible A retrospective clinical study Clin Implant Dent Relat Res 2003;5(Suppl 1):2–9.

17 Capelli M, Zuffeti F, Testori T, Del Fabbro M. Immediate rehabilitation of completely lous jaws with fixed prosthesis supported by upright and tilted implants A multicenter clinical study Int J Oral Maxillofac Implants 2007;22:639–44.

edentu-S Jivraj and H Zarrinkelk

© Springer International Publishing AG 2018

S Jivraj (ed.), Graftless Solutions for the Edentulous Patient, BDJ Clinician’s

Guides, https://doi.org/10.1007/978-3-319-65858-2_2

H.M Zarrinkelk, D.D.S ( * )

Diplomate, American Board of Oral and Maxillofacial Surgeons, Chicago, IL, USA

Fellow, American College of Oral and Maxillofacial Surgeons, Washington, DC, USA

Private Practice, Ventura, CA, USA

e-mail: DrZ@VenturaOralSurgery.com

S Jivraj, B.D.S., M.S.Ed

Herman Ostrow USC School of Dentistry, Los Angeles, CA, USA

Eastman Dental Institute, London, UK

Private Practice, Oxnard, CA, USA

According to the U.S. National Health Surveys conducted over the past five decades, rate of edentulism has been declining from 18.9% in 1957–1958 to 4.9% of the adult population in 2009–2012 (NHANES: U.S.  Depart of Health and Human Services) The continuing decline will be offset partially by population growth and

as well as pain and morbidity associated with grafting procedures are large cles to treatment There will be increased pressure on the medical community to reign in the cost associated with treatments rendered Clinicians are required to justify the rationale for more expensive and invasive procedures if less expensive and less invasive procedures are as effective There is growing evidence that eden-tulous patients can be treated with fixed full-arch dental appliances while avoiding major grafting procedures with as few as four dental implants [10–12] (Fig. 2.1) It

obsta-is with the above understanding that we begin to appreciate the great interest in the dental community to learn about the less invasive surgical concepts and protocols that rehabilitate the edentulous patient without bone grafts The goal of this chapter

is to provide a brief overview and introduction to the absolute surgical diagnostic and treatment planning requirements for surgeons and restorative dentists

Diagnosis and treatment planning of the edentulous patient is a complex and challenging task Treatment planning of this often older and medically compro-mised patient population should always begin with a complete medical evaluation

Fig 2.1 Successful, aesthetic and functional rehabilitation of patient utilizing graft-less approach

to maxilla and mandible Four implants per jaw were used in an immediate load protocol

H.M Zarrinkelk and S Jivraj

In brief, any uncontrolled disease process that would compromise complete bone and soft-tissue healing should exclude a patient from implant therapy Diabetes, osteoporosis, and cardiac and vascular disease may be of concern but if controlled are not absolute contraindications for implant therapy [13] Currently the most con-cerning and absolute contraindication for implant therapy is intravenous bisphos-phonate or other antiresorptive therapies [14]

The surgical evaluation of the patient’s oral condition should be systematic and methodical The diagnostic criteria are ultimately used by the surgeon to determine

the correct course of action to satisfy the three absolute surgical requirements:

1 Space: Adequate inter-arch space required for the prosthesis

2 Spread: Adequate A-P spread to support the prosthesis (Fig. 2.2)

3 Stability: High primary stability of placed dental implants

The surgical diagnostic criteria discussed in this chapter will apply to a patient who is being treatment planned for a full-arch, fixed metal-ceramic, hybrid [15], profile [16] or fixed-removable (Marius type) [17] prosthetic appliance The sur-geon must evaluate the following anatomic factors for all restorative options listed:

1 Magnitude of three-dimensional anatomical defect

2 The visibility of the prosthetic transition line

3 The volume and quality of bone available in the maxillary zones

4 Position of the inferior alveolar nerve and mental foramen

The prosthetic diagnostic criteria and concerns will be discussed in another lication in this series

pub-Loss of teeth and subsequent resorption of supporting structures create an tomical defect within the maxillofacial structures that will have profound influ-ence on the type of the restoration best suited to the patient Subsequently, the type of restoration selected to satisfy the patient’s condition and desires will

ana-Fig 2.2 The A-P spread is determined by the distance between the lines intersecting the platform

of the distal implants and the most anterior implants The A-P spread should be as large as possible

to compensate for the magnified occlusal forces of the cantilever

2 Diagnosis and Treatment Planning: A Surgical Perspective

determine the implant positions Therefore, loss of tissue should be assessed first

to determine the correct position of the osseous anchorage Loss of teeth creates a

“tooth-only” defect whereas subsequent loss of supporting bone and soft-tissue creates what is termed a “composite defect” [18] In patients where a tooth-only defect with minimum resorption of the supporting structures has occurred, a metal-ceramic implant- supported appliance is most aesthetic and appropriate However, in most cases edentulous patients present with varying degrees of hori-zontal as well as vertical composite defect To assess the magnitude of the resorp-tive defect, a dental set-up with appropriate tooth position, inter-arch relationship and occlusion must be fabricated The denture set-up is subsequently duplicated

in a transparent clear acrylic and worn by the patient With the clear denture in place two dimensions are measured:

1 The relative space between the cervical line of the denture teeth to the residual ridge: This measurement represents the available restorative space (Fig. 2.3)

2 The facial surface of teeth to apex of the residual crest, representing the lip port requirements

sup-With the data available from these two measurements the restorative and surgical clinicians can determine the appropriate appliance for the patient The decision to fabricate a metal-ceramic appliance with or without pink ceramic gingiva vs a hybrid appliance is made by the restorative dentist based on the relative position of the proposed teeth to the existing ridge The surgical specialist must have a clear understanding of the space required to satisfy the aesthetic and structural require-ments of the planned appliance [19, 20] In the case of a hybrid appliance roughly

15  mm of space is required per arch measured from the incisal edge to implant platform The management of restorative space is an absolute prosthetic require-ment but a surgical responsibility If insufficient inter-arch space is detected, then space should be created Most often the creation of space is accomplished by bone reduction or alveolectomy The surgeon and restorative dentist should collaborate

on determination of the magnitude of bone reduction required in each of the jaws to

Fig 2.3 Assessment of

available restorative space

by utilization of clear

acrylic dental set-up Note

the distance from planned

incisal edge to the existing

alveolar ridge Horizontal

and vertical relationship

between the incisal edge

and the alveolar ridge can

be measured

H.M Zarrinkelk and S Jivraj

satisfy prosthetic requirements The dimensions of alveolectomy are communicated

to the surgeon by the “bone reduction guide” This surgical stent is a tissue- or tooth-supported acrylic stent fabricated on an altered plaster model with markings for reduction (Fig. 2.4)

A large horizontal deficiency will create a prosthetic ledge which will be both unaesthetic and unhygienic for the patient The surgeon may alter the vertical posi-tion of the dental implants relative to the incisal edge to allow for an appropriate labial curvature of the appliance The available vertical dimensions of the bone must

be taken into consideration If insufficient vertical bone dimension exists to allow appropriate vertical position of the implants then a fixed-removable appliance with flange such as Marius Bridge may be selected [17]

The next step in clinical evaluation of patient is assessment of the “transition line” This line represents the junction of the dental prosthesis and residual alveolar gingiva The failure to assess the visibility of the transition line may result in an unaesthetic outcome for the patient (Fig. 2.5) The transition line may become vis-ible during normal animation of the lips particularly during smiling The edentulous

Fig 2.4 Examples of both tooth- and tissue-borne bone reduction guides This guide is used by

the surgeon to determine the desired position of the alveolar platform for implant placement The final incisal-edge position is simulated in the stent and surgeon removes appropriate height of alveolar bone to assure sufficient restorative space and proper prosthetic labial contours

Fig 2.5 Transition line is defined as the junction of hybrid dental prosthesis and natural gingiva

Assessment of visible alveolus (line) during lip animation and smiling is critical preoperatively to ascertain the magnitude of bone reduction in order to hide the transition line above the smile line and avoid an unaesthetic result for the patient (arrow)

2 Diagnosis and Treatment Planning: A Surgical Perspective

patients’ typical hesitation to smile during examination may be source of mation of the exposure Therefore, the evaluation of the lip animation should begin during the initial conversations with patients Next, lip length is measured from subnasale to stomion during maximal animation with the denture in place (Fig. 2.6) Subsequently the denture is removed and patient asked to smile and verified with measurement of lip length Any visible alveolar ridge during the maximal smiling is noted and measured Ideally in an edentulous patient the final transition line should

underesti-be 3–5 mm above the highest animated smile line For an edentulous patient with a visible ridge on smiling, the decision to conserve or resect alveolar bone is based on the patient’s aesthetic demands If artificial ceramic or acrylic gingiva is unaccept-able to the patient then the dental implants will have to be placed in precise teeth positions and a metal-ceramic prosthesis of appropriate teeth proportions con-structed If a patient has a composite defect and the ridge is visible then metal- ceramic prosthesis may not be feasible In this class of patients teeth will appear long and unaesthetic without gingival coloured soft-tissue component In a situation where alveolar ridge is visible and artificial gingiva are not of aesthetic concern to the patient then alveolar resection is indicated Extra attention should be paid to patients with short or hyperactive lips The dimension of alveolar reduction will be the sum of visible ridge measurement plus an additional 3–5 mm of reduction The entire visible alveolar ridge from the premaxilla to the tuberosity must be consid-ered when planning for alveolectomy Once the vertical dimensions of alveolec-tomy in all zones of the maxilla or mandible are determined the patient radiographs will be evaluated to assess the anticipated remaining alveolar bone below the sinus and nasal cavity and above the inferior alveolar nerve

The third and final step in systematic diagnosis of an edentulous patient is graphic determination of available bone for dental implant placement Availability

radio-of three-dimensional radiography and virtual planning sradio-oftware has made the nosis and treatment planning predictable Bedrossian has described the delineation

diag-of maxilla into three zones for a simplified treatment planning [18] A treatment plan can be developed by the clinician after determination of presence of sufficient bone in the three zones of the maxilla The alveolar bone of the anterior maxilla from canine to contralateral canine is designated as Zone 1, the premolar region as Zone 2 and the molar region as Zone 3 (Fig. 2.7)

Fig 2.6 The measurement of subnasale to stomion represents the lip length The change in this

measurement between repose and animation represents the magnitude of lip mobility and must be considered during treatment planning An active lip may necessitate substantial bone reduction to hide the transition line

H.M Zarrinkelk and S Jivraj

If zones 1, 2 and 3 have available bone volume then preferred number of axial implants may be placed (Fig. 2.8a) If zones 1 and 2 are available then tilted poste-rior implant in combination with axial or tilted anterior implants can be considered (Fig. 2.8b) And finally if zone 1 is the only available bone, then concepts of zygo-matic or pterygoid plate implants may be considered for posterior support and axial

or tilted implants for anterior support (Fig. 2.8c) If complete atrophy of the maxilla

is evident with unavailability of bone in all three zones of the maxilla then two zygomatic implants bilaterally may be used to provide support for the prosthesis (Fig. 2.8d) The reason for tilting of implant up to 45° is to avoid placement of implants in anatomic structures such as the maxillary sinus, nasal cavity or mental foramen Tilting of the distal implants allows increase in the A-P spread by position-ing the platform of the implant further posteriorly while avoiding the mentioned structures (Fig. 2.9) By bypassing these structures bone grafting procedures are avoided or minimized If any combination of the implant position schemes satisfies the three absolute requirements of spread, stability and space then immediate load-ing of the appliance may be considered

Fig 2.7 The three zones

of maxillary alveolar bone

used in a simplified

treatment planning

protocol as described by

Bedrossian Zone

1 = incisor region (red),

Zone 2 = bicuspid region

(gold), Zone 3 = molar

Selection of the appropriate implants for each case must begin with a complete understanding of the available implant systems and corresponding straight or angled prosthetic abutments Lekholm and Zarb [21] have classified the degree of resorption

of the alveolar process and basal bone A classification was also proposed for ated bone quality Selection of implant length and diameter is dependent on alveolar anatomy and bone density Thorough preoperative as well as intraoperative evalua-tion of the alveolar ridge will guide the diameter of implant used The goal of sur-geon should be to maintain adequate bone thickness of at least 2 mm along the entire length of the implant [22] Assuming that minimal implant diameter used will be narrow platform or 3.3–3.5 mm (Nobel Biocare, Zurich, Switzerland) a minimum of 5–6 mm of alveolar crest ridge width is required in planning of the implant positions Wider alveolar ridges allow for placement of wider implants with more flexibility of components and increased bone/metal contact surface area for osseointegration and therefore should be favoured Bone reduction creates decortication of the alveolar ridge and exposure of the spongy marrow space for implant placement Alveolar atrophy or bone reduction will have the beneficial effect of bringing the crest of the alveolus closer to confluence of dense bone plates of the piriform rim The position

associ-of the distal tilted implant should be so that the eventual prosthetic cantilever is mized Implant length selection is to assure primary stability by engagement of areas

mini-of dense bone such as the piriform rim, nasal floor or inferior border mini-of the mandible while placing the implant platform as far posteriorly as possible [23] (Fig. 2.10)

Fig 2.9 Tilting of the

implants up to 45° (blue)

allows distalization of the

platform of the implant

while avoiding structures

such as the maxillary sinus

The primary benefit of this

manoeuvre is the reduction

of the cantilever effect

(gold)

Fig 2.10 Primary stability of the implants placed is critical to osseointegration and success The

immediate stability is dependent on the design of implant used and the quality of bone engaged Goal should be to engage areas of jaws with dense bone such as inferior border of the mandible, nasal floor or piriform rim

H.M Zarrinkelk and S Jivraj

Therefore, in the maxilla the posterior implant if angled should be at the minimum long enough to reach from the bicuspid region to the piriform rim In the mandible the distal implant is positioned with the platform above the mental foramen and tilted

to avoid the anterior loop of the inferior alveolar nerve while engaging the dense inferior border cortex

Decision on the number of implants to be placed is beyond the scope of this ter and is not an absolute criteria for success The appropriate number of implants for each individual patient is dependent on factors such as health status, type of bone, type and size of implant used, type of prosthesis planned, biomechanical configurations of the placed implants and other variables [24] However as early as 1977 Brånemark suggested that positioning four implants in the edentulous maxilla and mandible in an adequate A-P spread configuration can successfully reconstruct the patient’s oral handicap and prevent further bone loss [25] Today, there is growing evidence that immediate loaded, axial or tilted dental implants utilizing the patient’s existing bone structures while following strict biological and biomechanics principles discussed can provide patients a viable long-term solution to edentulism [26–29]

3 Stellingsma C, Raghoebar GM, Meijer HJ, Batenburg RH. Reconstruction of the extremely rebreed mandible with interposed bone grafts and placement of endosseous implants A pre- liminary report on outcome of treatment and patients satisfaction Br J Oral Maxillofac Surg 1998;36:290–5.

4 Triplett RG, Nevins M, Marx RE, Spagnoli DB, Oates TW, Moy PK. Pivotal, randomized, parallel evaluation of recombinant human bone morphogenetic protein-2/absorbable collagen sponge and autogenous bone graft for maxillary sinus floor augmentation J Oral Maxillofac Surg 2009;67:1947–60.

5 Keller EE, Tolman DE, Eckert SE.  Maxillary antral-nasal inlay autogenous bone graft reconstruction of compromised maxilla: a 12 year retrospective study Int J Oral Maxillofac Implants 1999;14:707–21.

6 Block MS, Baughman DG. Reconstruction of severe anterior maxillary defect using tion osteogenesis Bone grafts and implants J Oral Maxillofac Surg 2005;63:291–7.

7 Aghaloo TL, Moy PK.  Which hard tissue augmentation techniques are the most cessful in furnishing bony support for implant placement? Int J Oral Maxillofac Implants 2007;22(suppl):49–70.

8 Blackburn TK, Cawood JI, Stoelinga PJW, Lowe D. What is the quality of evidence base for pre-implant surgery of the atrophic jaw? Int J Oral Maxillofac Surg 2008;37:1073–9.

9 Esposito M, Grusovin MG, Coulthard P, Worthington HV. The efficacy of various bone mentation procedures for dental implants: a Cochrane systematic review of randomized con- trolled clinical trials Int J Oral Maxillofac Implants 2006;21:696–710.

10 Brånemark PI, Svensson B, van Steenberge D.  Ten year survival rates of fixed prostheses

on four or six implants ad modum Branemak in full edentulism Clin Oral Implants Res 1995;6:227–31.

11 Agliardi E, Panigatti S, Clericó M, Villa C, Maló P. Immediate rehabilitation of the edentulous jaw with full fixed prostheses supported by four implants: interim results of a single cohort prospective study Clin Oral Implants Res 2010;21:459–65.

2 Diagnosis and Treatment Planning: A Surgical Perspective