Dental Implants and Bone Grafts

Materials and Biological Issues

Hamdan Alghamdi,John Jansen

• Éditeur: Woodhead Publishing
• Année: 2019
• ISBN:
  9780081024799
• Sujet: Tecnologia e ingegneria
• Sous-sujet: Scienza dei materiali

Dental Implants and Bone Grafts: Materials and Biological Issues brings together cutting-edge research to provide detailed coverage of biomaterials for dental implants and bone graft, enabling scientists and clinicians to gain a thorough knowledge of advances and applications in this field. As tooth loss and alveolar bony defects are common and pose a significant health problem in dental clinics, this book deals with timely topics, including alveolar bone structures and pathological changes, reviews of indications and advantages of biomaterials for dental implants and bone graft, design and surface modification, biological interaction and biocompatibility of modern dental implants and bone graft, and new frontiers. This book is a highly valuable resource for scientists, clinicians and implantologists interested in biomaterial and regenerative strategies for alveolar bone reconstruction.

• Focuses on the structure, function and pathology of alveolar bone system
• Considers the issues involved in selecting biomaterials for dental implants and bone grafts
• Discusses the requirements for optimal dental implant osseointegration and alveolar bone replacements/reconstruction
• Explains the biological basis of dental implants and bone grafts

Chapter 1

Alveolar bone science: Structural characteristics and pathological changes

Sundar Ramalingam^⁎; Chalini Sundar^†; John A. Jansen^‡; Hamdan Alghamdi^{§ ⁎} Department of Oral and Maxillofacial Surgery, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
^† Saudi Dental Society, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
^‡ Department of Biomaterials and Oral Implantology, Radboud University Medical Center, Nijmegen, The Netherlands
^§ Department of Periodontics and Community Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia

Abstract

The alveolar process is a major component of the tooth-supporting apparatus and is comprised of alveolar bone proper, cortical alveolar bone, alveolar crest, and trabecular bone. The alveolar process develops along with the dentition and undergoes resorption following extraction of teeth. With the advent of dental implant-supported rehabilitation, understanding and preserving the alveolar bone has become more imperative than ever before. In order to achieve the same, knowledge about applied biology, composition, microstructure, and anatomic, clinical, and radiographic features of alveolar bone is essential. The aim of this chapter is to help the reader gain a thorough knowledge of alveolar bone characteristics and its applied biology in relation to dental implants therapy.

Keywords

Alveolar bone; Embryology; Anatomy; Osteoblast; Osteoclast; Osteocyte; Periodontal tissue

Chapter outline

• 1.1 Introduction
• 1.2 Embryology of alveolar bone
• 1.3 Classification of alveolar bone
• 1.4 Alveolar bone proper, alveolar process, and alveolar crest
• 1.5 Composition and micro-structure of alveolar bone
• 1.6 Anatomic considerations of alveolar bone
• 1.7 Alveolar bone in disease and response to injury
• 1.8 Conclusion
• References

1.1 Introduction

Alveolar bone is a critical component of the tooth-supporting apparatus in the maxillofacial skeleton. A healthy alveolar process, comprising the alveolar bone, periodontal ligament, and cementum is required to maintain a healthy dentition [1,2]. Unlike other connective tissues, bone is a specialized connective tissue that is rigid and resilient. It is primarily responsible for supporting the soft tissue integument and protecting internal organs. The rigidity and resilience of bone are contributed by the mineralization of collagen fibers and noncollagenous proteins within the bone matrix [3,4]. Although alveolar bone is similar in microstructure and cellularity to bone in other parts of the body, the physiological and functional needs of the dental apparatus make it unique among all osseous tissues [3].

Anatomically, alveolar bone is exclusive to the maxilla and mandible, wherein it develops occlusal to the basal bone, coinciding with the development of dentition. In principle, the alveolar bone remains as long as the teeth are in occlusion, and undergoes resorption following loss of teeth [3,5]. With the advent of dental implantology and osseointegration, contemporary dentistry has undergone a paradigm shift towards rehabilitating missing teeth with different types of dental implants [6]. Since alveolar bone is an essential element for dental implant osseointegration, knowledge regarding the techniques to preserve and reconstruct alveolar bone have gained greater predominance over the last decade [1,3,5]. Understanding the biology and characteristics of alveolar bone have therefore become an imperative part of successful implant dentistry [7].

1.2 Embryology of alveolar bone

Alveolar bone development closely follows the development of maxilla and mandible through membranous ossification. Although maxillary and mandibular development begins as early as the fourth to sixth weeks of intrauterine life, alveolar bone development does not begin until the formation of teeth [2,3]. During the fourth week of intrauterine life, embryologic development of the face, including the upper face, midface (nasomaxillary complex), and mandible, begins from five primordia. These include the frontonasal process in the midline, and the bilateral maxillary and mandibular processes surrounding the primitive mouth or stomodeum [3,8] (Fig. 1.1). Both the maxillary and mandibular processes arise from the first branchial arch. While the mandible in its entirety is formed from the mandibular process, maxillary development along with the palate is contributed in part by the maxillary and frontonasal processes [3,8,9] (Fig. 1.2).

Fig. 1.1 Graphical representation of late fetal facial development in an anterior oblique view showing contributions from the different facial processes; frontonasal process (green), maxillary processes (orange), lateral nasal processes (yellow), medial nasal processes (purple), and mandibular processes (blue).

Fig. 1.2 Developmental origins of the maxillofacial skeleton in an adult (A) frontal view and (B) lateral view showing contributions from the maxillary processes (purple) and the mandibular processes (blue).

Mandibular bone formation begins bilaterally around the inferior alveolar nerve and its terminal incisive branch, thereby forming a bony groove housing those nerves. In addition, this bony groove also houses the developing tooth germs. Medial and lateral to this groove, alveolar bone plates extend superiorly to form the body of the mandible [3]. Anteriorly, the mandibular process merges across the midline giving rise to the mandible and anatomic lower third of the face along with tongue [9]. Nevertheless the mandibular symphysis remains in fibrous union until after birth, when it is finally ossified through membranous ossification [3,9].

Contrary to mandibular alveolar process development, maxillary alveolar development is more complex owing to the simultaneous development of maxillary antrum and associated midfacial (nasal, orbital, and maxillary) structures [3,8]. However, formation of the medial and lateral maxillary alveolar bone plates, enclosing the primary tooth germs, occurs in a similar fashion to that of the mandible. With time, the tooth germs develop and are progressively separated from each other by bony partitions, giving rise to the alveolar sockets that house the teeth and their supporting structures [3,8].

Embryologic development of teeth is attributed to the neuroectoderm or neural crest ectomesenchyme, which underlies the stratified squamous epithelium of primitive mouth or stomodeum. Around the sixth week of intrauterine life oral ectoderm in the primitive maxilla and mandible proliferates into horseshoe-shaped bands, signifying the future dentoalveolar processes [8,10]. This primary epithelial band gives rise to a superficial vestibular lamina and a deeper dental lamina. Both of these laminae proliferate into the underlying ectomesenchyme [8,10]. While the vestibular lamina grows rapidly and degenerates to form the labial or buccal vestibule, the dental lamina undergoes localized expansions called placodes, which develop subsequently into tooth buds. Altogether, the dental lamina gives rise to 52 tooth buds, 20 for primary teeth and 32 for permanent teeth through the lingually proliferating successional lamina [11–13]. The sequence of tooth development from the dental lamina to tooth eruption is shown in Fig. 1.3.

Fig. 1.3 Embryologic development of tooth and its supporting structures, showing the stages of...