Chapter 7: Peri-Implantitis: Basics and Beyond 2 CE Hours By: Dr. Madhumietha Arumugam, B.D.S., M.D.S. Learning objectives Define peri-implantitis and peri-implant mucositis. Contrast differences between peri-implantitis and peri-implant Discuss the prevalence of peri-implantitis and peri-implant mucositis. mucositis. Outline the histology of peri-implant tissues. Describe the management strategies for peri-implantitis. List the grades of classification of peri-implantitis. Explain Cumulative Interceptive Supportive Therapy for peri- Identify the risk factors associated with peri-implantitis. implantitis. Explain etiopathogenesis of peri-implantitis. Summarize the clinical implications of peri-implantitis and the Discuss the steps involved in obtaining the diagnosis of peri- importance of implant maintenance. implantitis. Introduction Dental implants have seen a big boom in the field of dentistry, and defined as an inflammatory process affecting the tissues around an have emerged as a new vista in the arena of full mouth rehabilitations. osseointegrated implant in function, resulting in loss of supporting bone. It has been estimated that 2 million implants will be installed annually Peri-implant mucositis is defined as reversible inflammatory changes of and this number is expected to rise in the coming years. Hence, the the peri-implant soft tissues without any bone loss [3]. maintenance of the dental implants becomes an important matter Prevalence of peri-implantitis and peri-implant mucositis of subject. Akin to the natural teeth, implants emerge through the The sixth European workshop of periodontology on peri-implant oral mucosa and are susceptible to plaque formation and disease diseases has stated that peri-implant mucositis occurs in about 80 [1, 2]. progression in the susceptible host percent of subjects (50 percent of sites) restored with implants, and Definitions peri-implantitis in between 28 percent and 56 percent of subjects (12– The latest consensus about peri-implant diseases, reached in the seventh 40 percent of sites) [4]. This course will explore in detail the histology European Workshop on Periodontology has affirmed the definitions of peri-implant tissues, classification, risk factors, microbiology, of peri-implantitis and peri-implant mucositis. Peri-implantitis was etiopathogenesis, and management of peri-implantitis. Histology of peri-implant tissues The soft tissue surrounding healthy osseointegrated dental implants ‘biological barrier,’ and protects the zone of osseointegration from shares anatomic and functional features with the gingiva around teeth. factors released from plaque and the oral cavity. The connective tissue The outer surface of the peri-implant mucosa is lined by a stratified can be divided into an inner zone and an outer zone. keratinized oral epithelium that is continuous with a junctional The inner zone is 50-100 µm wide with collagen fibers aligned parallel epithelium attached to the titanium surface by a basal lamina and by to the implant surface. The outer zone consists of collagen fibers in hemi-desmosomes. The peri-implant epithelium is a keratinized, multi- various directions and is highly vascularized [5]. layered squamous epithelium with four layers: ● Stratum basale with cylindrical or cubical mitotic active cells. The biologic width of an implant can be defined as the distance ● Stratum spinosum. from most coronal extension of the junctional epithelium to the ● Stratum granulosum. alveolar bone. The average biologic width around an implant is ● Stratum corneum. ~3mm, consisting of 1.8mm of junctional epithelium and 1.05mm of connective tissue attachment [6]. Supracrestal implant surface The junctional epithelium is separated from the alveolar bone by with an apical coronal expansion of at least 3 mm is essential for the collagen-rich connective tissue, which is ~3 to 4mm. This forms a development of a stable biologic width. Classification of peri-implantitis Various authors have classified peri-implantitis for ease of classifications are listed below. Spiekermann (1995) has classified peri- communication and management. Some of the commonly used implantitis into four classes such as follows [7]: CLASS I Slight horizontal bone loss with minimal peri-implant defect. CLASS II Moderate horizontal bone loss with isolated vertical defect. CLASS III Moderate horizontal/vertical bone loss with circular bony defects. CLASS IV Advanced bone loss with broad, circumferential vertical defects as well as loss of buccal and/or palatal bony wall. Schwarz et al. (2007) have classified the bone defects that occur in Class II – supra alveolar bone defects. Generally, a combination of peri-implantitis [8]. They classified bone defects as: Class I –intra class I and class II defects is observed at one implant. Class I was osseous bone defects. further classified as: Dental.EliteCME.com Page 96 CLASS 1A Buccal or oral dehiscence defects with position of the implant body within or beyond the envelope. CLASS 1B Buccal or oral dehiscence defects with semi-circular bone resorption to the middle of the implant body (position of the implant body within or beyond the envelope). CLASS 1C Dehiscence defects with circular bone resorption under maintenance of the buccal or oral compact layer (position of the implant body within or beyond the envelope). CLASS 1D Circular bone resorption with buccal and oral loss of compact bone layer (position of the implant body within or beyond the envelope). CLASS 1E Circular bone resorption under maintenance of the buccal and oral compact layer. Forum and Rosen (2012) have classified peri-implantitis as early, moderate, and advanced based on the probing depth and the amount of bone loss [9]. It is as follows: Early PD ≥ 4 mm (bleeding and/or suppuration on probing). Bone loss < 25 percent of the implant length. Moderate PD ≥ 6 mm (bleeding and/or suppuration on probing). Bone loss 25 to 50 percent of the implant length. Advanced PD ≥ 8 mm (bleeding and/or suppuration on probing) Bone loss > 50 percent of the implant length. Risk factors associated with peri-implantitis A plethora of risk factors have been implicated in the etiopathogenesis [14, 15]. Glycated hemoglobin, or HbA1C, diabetic control is an of peri-implant diseases, enlisted below: important factor when assessing the relationship between diabetes ● Plaque – Peri-implant diseases have been implicated with and peri-implantitis. High blood glucose level can impact tissue microbiota resembling that of gingivitis and periodontitis. High repair and host defence mechanisms, as diabetic control affects proportions of anaerobic gram-negative rods, motile organisms, neutrophil function [16]. As a result, diabetes can disrupt collagen and spirochetes have been denoted, but this association does not homeostasis in the extracellular matrix and is associated with necessarily prove a causal relationship. Healthy peri-implant neutrophil dysfunction and imbalance of immune system. Thus, sulcus is characterized by high proportions of coccoid cells, a the tissue repair ability and defensive mechanisms of diabetic low ratio of anaerobic/aerobic species, a low number of gram- patients to the insult of dental plaque are impaired [17]. Additional negative anaerobic species, and low detection frequencies for prospective cohort studies are needed to clarify the association periodontopathogens [10]. Implants with peri-implantitis reveal between diabetes and peri-implantitis. a complex microbiota encompassing conventional periodontal ● Residual cement – Many recent studies have confirmed residual pathogens such as A. actinomycetemcomitans, P. gingivalis, cement to be a risk factor for peri-implant diseases [18]. The presence T. forsythia, P. micra, C. rectus, F. nucleatum, P. intermedia, of residual cement makes the subgingival space more prone for plaque [19] T. denticola, and Capnocytophaga [10]. Other species, such as accumulation and progression of peri-implant diseases . Hence it Pseudomonas aeruginosa, Enterobacteriaceae species, C. albicans, has been advised to evaluate both clinically and radiographically for or staphylococci are also frequently detected around implants. any residual cement left after the crown placement. These organisms are uncommon in the subgingival area but have ● Genetic traits – Genetic variations have been implicated with been associated with refractory periodontitis. High proportions of peri-implantitis, especially IL-1 gene polymorphism. However, Staphylococcus aureus and S. epidermidis on oral implants have conflicting results exist and future prospective studies are been reported. Recently, presence of Candida species has been needed to establish the relationship. A systematic review with isolated from failing peri-implant sites [11].. twenty-seven relevant articles found no consensus among the [20] ● History of periodontitis – Substantial evidence suggests that studies reviewed . However another study on IL-1RN gene patients with a history of periodontitis show an increased risk for polymorphism concluded that it is associated with peri-implantitis [21] . peri-implant diseases compared with non-periodontitis patients [12]. and may represent a risk factor . Implants placed in patients suffering from aggressive periodontitis ● Occlusal overload – Non-axial occlusal load can be very have a tendency for greater crestal bone level changes and destructive to implants and are considered less tolerable to them probing pocket depth. The consensus report of the sixth European compared to