Deporter / Ketabi Immediate Molar Implants

1. Auflage 2022
ISBN: 978-1-64724-163-6
Verlag: Quintessence Publishing Co, Inc
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 252 Seiten

There is no one way to approach immediate implant placement in molar sites, but each technique has the same prerequisites: careful case selection and planning, good working knowledge of anatomy and bone biology, expertise in localized and indirect sinus floor elevations, and knowing when and how to use particulate bone grafting. But even with such knowledge, clinicians still need guidelines to show them how to achieve predictable success. This book is that guide. It brings together clinical experts in the field who having been leading the research on immediate molar implants over the last decade and it describes the current best practices to ensure implant success. Emphasis is placed on assessment of the implant site, particularly regarding classification of the molar septum bone, and how to achieve optimal implant positioning within the molar socket. The role of digital treatment planning and guided surgery is discussed, as are application of bone grafts and other biomaterials to enhance healing. Immediate molar implants have become a more viable treatment option than ever before, and this book will help clinicians move forward with confidence.

'Douglas Deporter, dds, dipl perio, phd Professor Discipline of Periodontology and Oral Reconstruction Center Faculty of Dentistry University of Toronto Toronto, Canada Mohammad Ketabi, bds, dds, mds Professor Department of Periodontology and Implant Dentistry Faculty of Dentistry Islamic Azad University, Isfahan Branch Isfahan, Iran Adjunct Professor Faculty of Dentistry University of Toronto Toronto, Canada'

Autoren/Hrsg.

Deporter, Douglas

Ketabi, Mohammad

Leseproben

1

Introduction to Immediate Molar Treatment Options

Douglas Deporter

The use of endosseous dental implants to replace missing or hopeless teeth has become routine practice in contemporary patient treatment. Indeed, implant-supported or implant-retained prostheses often are considered the treatment of first choice in both partial and complete edentulism because of their reported excellent long-term performance and patient satisfaction. Nevertheless, while treatment costs for a single implant-supported molar crown can be comparable to a three-unit, tooth-supported fixed partial denture, the longer treatment times and multiple interventions needed to complete the implant-based treatment do remain hurdles in gaining patient acceptance.1,2 The original and well-tested principles of implant placement in healed extraction sites with a submerged initial healing interval continue to be used, and certainly molar replacement with single implants using this approach is reported to be predictably successful in the long term, particularly in the mandible and when natural teeth are present on either side of the implant.3–8 However, the public is now aware of accelerated treatment approaches such as All-on-4 and “Teeth in a day” that provide immediate implant placement and immediate implant function. This awareness has fed the need to develop faster but equally successful treatment protocols for molar replacement. One such protocol is the replacement of condemned molar teeth using immediate implant placement with or without immediate function, and this book reviews the history, current status, technique prerequisites, and recent advances for this approach using a variety of implant types.

Timing of Implant Placement

Several classifications have been proposed to specify the timing of implant placement in relation to tooth extraction.9–12 We have chosen the classification of Hämmerle et al,11 which is based on the extent of both soft and hard tissue healing after tooth extraction. Hämmerle’s type 1 sites are those where an implant is placed into a fresh extraction socket. Type 2 sites are referred to as early placement sites, ie, those where an implant is delayed until soft tissue closure over the extraction site has been achieved (typically 4 to 8 weeks). Type 3 sites are referred to as delayed implant placement sites, meaning those sites where substantial new bone formation has been allowed to happen before implant placement (typically 12 to 16 weeks). Finally, type 4 sites are those where the extraction sites have healed fully (ie, longer than 16 weeks), the tooth having been removed at some point in the distant past. The suggested advantages and disadvantages of the four types are summarized in Table 1-1.11

Table 1-1

Classification of timing of implant placement*

Classification	Definition	Advantages	Disadvantages

Type 1

Implant placement immediately following tooth extraction and as part of the same surgical procedure

• Reduced number of surgical procedures • Reduced overall treatment time • Optimal availability of existing bone

• Site morphology may complicate optimal placement and anchorage • Thin tissue biotype may compromise optimal outcome • Potential lack of keratinized mucosa for flap adaptation • Adjunctive surgical procedures may be required • Procedure is technique sensitive

Type 2

Complete soft tissue coverage of the socket (4–8 weeks)

• Increased soft tissue area and volume facilitates soft tissue flap management • Resolution of local pathology can be assessed

• Site morphology may complicate optimal placement and anchorage • Treatment time is increased • Socket walls exhibit varying amounts of resorption • Adjunctive surgical procedures may be required • Procedure is technique sensitive

Type 3

Substantial clinical and/or radiographic bone fill of the socket (12–16 weeks)

• Substantial bone fill of the socket facilitates implant placement • Mature soft tissues facilitate flap management

• Treatment time is increased • Adjunctive surgical procedures may be required • Socket walls exhibit varying amounts of resorption

Type 4

Healed site (> 16 weeks)

• Clinically healed ridge • Mature soft tissues facilitate flap management

• Treatment time is increased • Adjunctive surgical procedures may be required • Large variations are present in available bone volume

* Reprinted with permission from Hämmerle et al.11

From the patient’s point of view, type 1 implantation, ie, truly immediate, is the most desirable as it takes the least time and least number of surgical interventions to achieve. There are, however, technical challenges for the surgeon, such as avoiding bur chatter, controlling the final implant position, gaining sufficient primary stability, and maintaining and/or manipulating adequate soft tissue for appropriate site closure.13 If the site has a thin gingival biotype preoperatively (ie, < 2-mm soft tissue thickness) and/or minimal keratinized gingival tissue (< 2-mm width), even if it is possible to stabilize an immediate molar implant (IMI), its health in the long term may be compromised because of an increased risk of peri-implant crestal bone loss needed to reestablish biologic width relative to implant type and placement depth.14–20 Thus, van Eekeren et al19 recently reported that gingival biotype had an impact on bone-level implant placement but not on tissue-level implant placement or when the implant-abutment connection was at least 2.5 mm above the crestal bone level. They suggested that when treating patients with initial mucosal thicknesses of 2 mm or less, choosing a tissue-level implant with the implant-abutment connection 2.5 mm above the crestal bone level for a posterior site (ie, esthetically less demanding) could help to minimize crestal bone loss. These considerations help to explain why IMIs are classified as being difficult and requiring considerable experience and ability of the surgeon.21

The decision to undertake early implantation (type 2, after 4 to 8 weeks of site healing) could be made for a variety of reasons, such as an existing acute local infection at extraction or a desire to permit some soft tissue healing and increases in amount and thickness of keratinized tissue before implant insertion. However, it needs to be remembered that some loss of alveolar ridge width and height will certainly have occurred, especially if a flap had been raised for the extraction, as most alveolar remodeling happens within the first 3 to 6 months postextraction.22 Outcomes following early placement in various tooth sites can be comparable with those following immediate or delayed implant placement.23,24 Early implant placement after a ridge preservation grafting procedure done at the time of extraction also may be a helpful protocol,25 although it would add at least one extra surgical procedure. Most recently, however, it has been reported that early placement after extraction can give success rates similar to ridge preservation grafting and implant placement after 4 months of healing, at least at nonmolar sites.26

The benefits of waiting 12 to 16 weeks postextraction (type 3 sites) are that substantial new bone formation will have occurred within the socket and that the state of maturity of the gingival tissues will facilitate their manipulation. The disadvantages of this approach are again the loss in alveolar ridge dimensions, the longer treatment times, and the fact that additional surgical costs may be incurred. For example, it may become necessary to use commercial graft and barrier materials to thicken thin cortical bone buccally after osteotomy preparation, manage bony dehiscences, and/or regain local ridge anatomy to optimize patient comfort and prosthetic emergence profiles.

Rationale and Early Work with IMIs

One of the original goals with immediate implant placement was that it would avoid or at least minimize the rapid alveolar ridge shrinkage that occurs both vertically and horizontally during normal extraction site healing. The greatest loss in alveolar ridge dimensions happens within the first 3 months postextraction, and by 1 year, buccolingual or buccopalatal ridge width shrinkage can be as high as 50%.22,27 Worse still is the fact that the greatest loss in width happens midbuccally at the extraction socket, ie, exactly where the clinician wishes to locate an implant.28 Looking at available human data, however, while losses in alveolar dimension can be reduced following immediate implant placement, they cannot be eliminated because many factors contribute to the losses.29–33 Even when...