Early marginal bone loss around dental implants to define success in implant dentistry: A retrospective study

Abstract

Purpose The aim of this study was to establish an objective criterion in terms of marginal bone level (MBL) to know the prognosis of an implant. Materials and Methods A group of 176 patients in whom 590 implants were placed were included in this retrospective study. Patients older than 18 years, presenting either Kennedy class I or II edentulous section, or totally edentulous at least in one of the dental arches were included in this study. Those with any type of disturbance able to alter bone metabolism or with nontreated periodontal disease were excluded. Data on radiographic MBL at loading, 6 and 18 months later, age, gender, smoking habits, history of periodontitis, bone substratum, implant, and prosthetic features were recorded. Nonparametric receiver operating curves (ROC) were constructed for the MBL at 18 months in order to establish a distinction among high bone loser (HBL) and low bone loser (LBL) implants. Differences as a function of main variables were also determined, particularly abutment height and periodontal disease. Results HBL implants lost at least 0.48 mm of MBL 6 months after loading; they reached at least 2 mm of MBL 18 months after loading. MBL rate followed a nonlinear trend, except in implants restored over long prosthetic abutments and in patients with history of severe periodontitis; in whom the rate of MBL over the time was nearly zero. Conclusion Implants that lose more than 0.5 mm of marginal bone 6 months after loading are at great risk of not being radiographically successful anymore. Therefore, 0.5 mm of MBL is proposed as a distinctive and objective criterion of success in Implant Dentistry within a 6‐month follow‐up period. A prosthetic abutment height ≥2 mm resulted the most protective factor in the peri‐implant bone maintenance.

Impact of peri‐implant soft tissue characteristics on health and esthetics

“…In fact, it has been shown that if initial marginal bone loss exceeds 0.5 mm over the first 6 months, it is very likely that the loss will extend to 2 mm after 2 years, increasing the risk for the occurrence and progression of peri-implantitis. 55 A 10-year prospective study validated that implants that exceed 0.5 mm during the first year of function are 5.43 times more prone for future periimplantitis development. 56 In relation to these observations, it has been speculated that the partial exposure of implant surface to the peri-implant sulcus can facilitate bacterial colonization, which may increase the risk for inflammatory disease.…”

“…Although there is no conclusive clinical evidence indicating that there is a direct link between a certain threshold of STH and an increased risk for the development of peri‐implant diseases, early marginal bone loss, although often self‐limiting, may jeopardize long‐term health. In fact, it has been shown that if initial marginal bone loss exceeds ~0.5 mm over the first 6 months, it is very likely that the loss will extend to 2 mm after 2 years, increasing the risk for the occurrence and progression of peri‐implantitis 55 . A 10‐year prospective study validated that implants that exceed 0.5 mm during the first year of function are 5.43 times more prone for future peri‐implantitis development 56 .…”

A Two-Year Follow-Up Assessment of Decreasing Crestal Bone Levels Around Dental Implants in Patients Rehabilitated With Mandibular Implant Overdentures

“…Bone loss associated with dental implants is one of the most studied and experimented with topics in implant dentistry. It has been widely debated and researched across the globe for decades still one has formulated a concrete statement or concept [15][16][17]. Recently many pioneer researchers, including Young et al, studied variants of CBCT and its role in dental implantology, and they claimed that CBCT is an ideal radiographic tool for estimating alveolar bone losses [18].…”

Marginal bone changes around platform‐switched conical connection implants placed 1 or 2 mm subcrestally: A multicenter crossover randomized controlled trial

“…Traditionally, EMBL up to 1.5–2 mm followed by a maximum of 0.2 mm annually thereafter, was commonly observed and considered a defining criterion of implant success 21–23 . The definition of success in implant dentistry has evolved in recent years and EMBL <0.5 mm is currently accepted as a threshold between peri‐implant bone physiological stability and a borderline condition potentially favoring subsequent peri‐implant pathology 24–29 . EMBL may lead to unwanted treated implant surface exposure to the oral cavity microbiome and surface roughness facilitates bacterial biofilm adhesion, maturation, and colonization.…”