Ridge Augmentation Procedures in Implant Patients

A Staged Approach

Luca Cordaro, Hendrik Terheyden, Stephen Chen, Daniel Buser, Daniel Wismeijer, Stephen Chen, Daniel Buser, Daniel Wismeijer

• Publisher: Quintessence Publishing
• Year: 2019
• ISBN:
  9783868674989
• Edition: 1
• Topic: Medicine
• Subtopic: Dentistry

Volume 7 of the ITI Treatment Guide series provides clinicians with the latest evidence-based information on the techniques and materials utilized for ridge augmentation. An up-to-date analysis of the current evidence is based in part on the proceedings of the ITI Consensus Conferences in Stuttgart (2008) and Bern (2013) and on a review of the current literature. Twelve clinical cases demonstrate the planning and treatment principles required to successfully rehabilitate patients with varying degrees of ridge atrophy.The ITI Treatment Guide series is a compendium of evidence-based implant-therapy techniques and procedures for daily practice. Written by renowned clinicians and supported by contributions from expert practitioners, the ITI Treatment Guides provide a comprehensive overview of various clinical options. The management of different clinical situations is discussed with an emphasis on sound diagnostics, evidencebased treatment concepts, and predictable treatment outcomes with minimal risk to the patient.

1	Introduction
	H. Terheyden, L. Cordaro

Augmentation procedures to increase the volume of deficient or atrophic alveolar bone have been extensively described in the literature. They are widely performed by numerous surgeons all over the world in an effort to safely place implants where they can support an adequate functional and esthetic prosthesis.

The past few years have seen the development of surgical techniques to deal with bone defects of almost any shape or size, regardless of whether they result from ridge atrophy, trauma, inflammation, tumors, or malformation. Ridge augmentation may, however, run up against limitations and complications for a number of reasons, such as general health issues, dental status, extent and location of the bone defect, patient preference, reluctance to undergo major surgical procedures, or budget considerations.

Generally speaking, the prognoses for implant survival are no less favorable in regenerated bone than in pristine bone.

Ridge augmentation serves three primary objectives:

•Function: to create a volume of vital bone that will accommodate a dental implant sufficiently long and wide for its ideal restorative and functional position.

•Esthetics: to give the associated soft tissues the bony support needed for an esthetic appearance of gingival/mucosal and facial structures.

•Prognosis: to create sufficient bone volume coronally around the neck of the implant to cover the endosseous implant segment, ensuring a tight softtissue seal and a predictable long-term prognosis of the implant.

Secondary goals in selecting a specific approach would be to keep the surgical technique straightforward, to minimize the surgical and postoperative burden for the patient, to ensure low morbidity, and to reduce the number of surgical sessions. Consideration is also given to cost, predictability, and healing time. Clinicians should realize that there may be one or several restorative options to meet the functional and esthetic requirements of a given patient. It is the treatment provider’s responsibility to study these options, propose the best solution and then present the patient with the expected outcome of this favored restorative strategy either in the form of a provisional denture setup and try-in or within an appropriate software environment. In doing so, the patient will have a clear understanding and no misconceptions about the appearance of the final prosthesis. This early preview of the treatment endpoint will clearly disclose any need for bone augmentation procedures to correct deficiencies in the underlying hard and soft tissues.

Anticipating patient requirements in this way has come to be known as “backward planning” and the treatment strategies derived from it as “restoration-driven” (or “prosthetically driven”) approaches. It is part of this rationale that a dentist, rather than accepting a restorative compromise, should consider reconstructing the bone to meet the restorative needs.

Also, there should be no reason for clinicians to withhold from their patients useful procedures of bone augmentation merely because they personally lack the skills to conduct these procedures on their own. It is better to refer a patient to an oral or maxillofacial surgeon than to accept a compromise that may be limiting to the restorative outcome. That said, the referring clinician should still have a good knowledge in the basics of bone augmentation and related options to advise their patients correctly, and it is important to ensure good collaboration between all members of the clinical team.

The focus of this volume will be on procedures of ridge augmentation performed on healed sites in preparation for delayed implant placement. This approach, here called the “staged” approach (which does not imply that the augmentation procedure itself consists of multiple stages) differs from simultaneous procedures of bone augmentation and implant placement in that they are broken down into an initial surgical session to augment the ridge and a second session for implant placement further down the line. The simultaneous approach is not extensively discussed in this volume. Procedures of sinus floor elevation have been covered extensively in Volume 6 of this ITI Treatment Guide series, and the reader is referred to Volume 3 for details on bone augmentation to support implant procedures in postextraction sites.

It is the authors’ ambition to provide the reader with a systematic way of assessing bone defects that may underlie specific clinical situations and to offer guidelines toward selecting the most appropriate surgical strategies to deal with specific defect types.

2	Consensus Statements on Ridge Augmentation and Review of the Literature

Various groups were appointed to deal with different topics at the 4th ITI Consensus Conference in Stuttgart in 2008. Group 4 was assigned to review surgical techniques and biomaterials used in implant dentistry and to evaluate the available evidence supporting their use. Two of four review papers that had been prepared for Group 4 were devoted to materials and methods for ridge augmentation:

•Simon Storgård Jensen and Hendrik Terheyden: Bone augmentation procedures in localized defects in the alveolar ridge: Clinical results with different bone grafts and bone-substitute materials. A review (Jensen and Terheyden 2009)

•Matteo Chiapasco, Paolo Casentini and Marco Zaniboni: Bone augmentation procedures in implant dentistry (Chiapasco and coworkers 2009).

These review papers formed the basis for discussing and subsequently formulating a series of consensus statements and recommendations for clinical procedures (Chen and coworkers 2009). Section 2.1 summarizes the consensus statements and clinical recommendations pertaining to ridge augmentation procedures. Section 2.2 will then update the reader on the more recent literature that has been added since these consensus statements were published in 2009.

2.1	Consensus Statements and Treatment Guidelines Formulated at the 2008 ITI Consensus Conference

2.1.1Consensus Statements

General statements

•Several surgical procedures are available and effective for the augmentation of deficient edentulous ridges to allow implants to be placed. However, most of the studies are retrospective in nature, with small sample sizes and short follow-up periods.

•Therefore, direct comparisons between studies should not be made and definitive conclusions cannot be drawn.

•There are a variety of defect situations with increasing complexity ranging from fenestrations, to dehiscences, to lateral deficiencies, and to vertical deficiencies including combinations of these.

•There are a variety of augmentation materials available with different biologic and mechanical properties ranging from particulate alloplastic materials to intraorally harvested block grafts.

•Survival rates of implants placed in regenerated bone after treatment of localized defects in the alveolar ridge are comparable to survival rates of implants placed in native bone.

•It was not possible to demonstrate the superiority of one augmentation technique over another based on implant survival rates.

Dehiscence- and fenestration-type defects

•Augmentation of dehiscence- and fenestration-type defects is effective in reducing the amount of exposed implant surface. Complete resolution of dehiscence and fenestrationtype defects cannot be predictably accomplished irrespective of the grafting protocol employed.

•Increased defect fill was observed when the augmentation procedure included the use of a barrier membrane.

•Survival rates of implants placed simultaneously with augmentation of dehiscence or fenestration type defects are high.

Horizontal ridge augmentation

•Techniques are available to effectively and predictably increase the width of the alveolar ridge.

•Augmentation utilizing autologous bone blocks with or without membranes results in higher gains in ridge width and lower complication rates than the use of particulate materials with or without a membrane.

•Survival rates of implants placed in horizontally augmented alveolar ridges are high.

Vertical ridge augmentation

•Techniques are available to increase the height of the alveolar ridge. However, their predictability is substantially lower compared to horizontal ridge augmentation procedures.

•Augmentation utilizing autologous bone blocks with or without membranes results in higher gains in ridge height than the use of particulate materials with or without a membrane.

•The complication rate related to vertical augmentation of the alveolar ridge is substantially higher compared to horizontal ridge augmentation procedures.

•Survival rates of implants placed in vertically augmented alveolar ridges are high.

Maxillary sinus floor elevation using the transalveolar approach

•Maxillary sinus floor elevation using the transalveolar approach is predictable for augmenting bone in the posterior maxilla.

•A variety of grafting materials can be safely and predictably used, alone or in combination. These materials include autografts, allografts, xenografts, and alloplastic materials.

•At present, it is not clear whether the introduction of a grafting material improves the prognosis.

Onlay bone grafting of extended resorption of edentulous ridges

•Autologous onlay bone grafting procedures are effective and predictable for the correction of severely resorbed edentulous ridges to allow implant placement. An uneventful healing/consolidation of grafts taken from intra- and/or extraoral donor sites occurs in the majority of cases.

•Acceptable survival rates of implants placed in maxillae and mandibles reconstructed with autologous onlay bone grafts are reported. The survival rates are slightly lower than those of implants placed in native bone.

Maxillary sinus floor elevation using the lateral approach

•Maxillary sinus floor elevation procedures are predictable for augmenting bone in the posterior maxilla.

•A variety of grafting materials can be safely and predictably used, alone or in combination. These materials include autografts, allografts, xenografts, and alloplastic materials.

•The use of autografts does not influence survival rates of rough surface implants, but may reduce healing times.

•The quantity and quality of bone in the residual maxilla influence survival rates of implants independently from the type of grafting procedure.

•Survival rates of rough surface implants placed in augmented maxillary sinuses are similar to those of implants inserted in native bone.

Split-ridge/ridge expansion techniques with simultaneous implant placement

•Split-ridge and expansion techniques are effective for the correction of moderately resorbed edentulous ridges in selected cases.

•Survival rates of implants placed at sites augmented using split-ridge/ridge expansion techniques are similar to those of implants inserted in native bone.

Split-ridge technique with interpositional bone grafts

•There is a lack of evidence concerning the split-ridge technique with interpositional bone graft and delayed implant placement.

Vertical distraction osteogenesis

•Alveolar distraction osteogenesis can be used to augment vertically deficient alveolar ridges in selected cases.

•Alveo...

Table of contents

• ITI Treatment Guide: Volume 7
• Title
• Copyright
• Preface
• Acknowledgment
• Editors and Authors
• Contributors
• Table of Contents
• 1. Introduction
• 2. Consensus Statements on Ridge Augmentation and Review of the Literature
• 3. Preoperative Assessment and Planning
• 4. Methods for Ridge Augmentation
• 5. Implant Placement in Augmented Sites and Treatment Outcomes
• 6. Clinical Case Presentations
• 7. Management of Complications
• 8. Conclusions
• 9. References