The Etiology and Causative Factors in Peri-Implant Disease: Mini Review

Aim: To detect the high and low risk factors behind the peri-implantitis disease that will provide evidence to clinician during diagnosis stage
Material and method: An online and hand-search of the published literature was conducted to identify studies that Examined peri-implantitis. The search terms that were used, alone or in combination, were peri-implant mucositis, peri-implantitis, implant complication and crestal bone resorption.
Results: Sixty-four studies were selected for comparison and to address the details emphasized in this study. Some of the articles were not directly related to peri-implant diseases but were reviewed for better understanding histology and examination of the tissue around implant.
Conclusion: Peri-implantitis disease is a multi-factorial disease that shared between the surgical, prosthodontic, tissue health and the patient care. plque retention around implant with weak soft tissue attachment in combined with poor hard and soft tissue thickness all work together to initiate per-implant disease.

Dental implants are commonly used for the replacement of missing teeth in patients with partial or complete edentulism. Results of long-term follow-up studies (Toy & Uslu, 2020; Chrcanovic et al., 2020; Kim et al., 2020) have shown that dental implants can demonstrate success and survival rates of 100%. However, biological complications associated with dental implants (peri-implant diseases, namely peri-implant mucositis and peri-implantitis) may jeopardize the integrity of peri-implant mucosa and supporting alveolar bone (Klinge et al., 2018). Different methods have been used to assess peri-implant tissue health and to diagnose these disease entities. These methods include peri-implant probing, analyses of peri-implant crevicular fluid or saliva, evaluation of the peri-implant microbiota and radiographic evaluation of the peri-implant bone levels. The current consensus indicates that changes in probing depth, and the presence of bleeding on probing and suppuration, must be evaluated to assess the peri-implant tissues, whilst radiographs should be used to confirm peri-implant bone loss (Serino et al., 2013). The reported prevalence of peri-implantitis varies from less than 7% to 37% of implants (Klinge, 2012). The variation can be attributed to differences in studied populations, length of follow-up time, implant variables, and the criteria used to define peri-implantitis (Koldsland et al., 2010). Two systematic reviews concluded that peri-implantitis affected 10% of implants and 20% of patients during the 5 to 10 years after placement (Mombelli et al., 2012; Atieh et al., 2013).

To focus on the role of plaque-biofilm to jeopardize the implant health.
And the importance role of the maintenance phase in prevention of implant failure, and increase the successful rate.
 

A search of the MEDLINE (PubMed) and Google scholar database was conducted, and the works published in the English language from 1990 until 2023 were included in the review. The search terms that were used, alone or in combination, were peri-implant mucositis, peri-implantitis, implant complication and crestal bone resorption. Titles and abstracts were screened, and a full-text analysis was performed for relevant publications. A manual search was conducted for the following journals from 1990 until 2023: Clinical Implant Dentistry and Related Research; Clinical Oral Implants Research; International Journal of Oral & Maxillofacial Implants; Journal of Clinical Periodontology; Journal of Dental Research; International Journal of Periodontics and Restorative Dentistry; Journal of Periodontology; Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics; British Journal of Oral and Maxillofacial Surgery; and Journal of Prosthetic Dentistry.
Inclusion criteria including studies with the following designs were included
1-Randomized controlled clinical trials, controlled trials, and prospective and retrospective clinical studies
2- invitro studies
3-literature review
The following publications were excluded from our data
1-Case reports or a case series
2-Studies in a language other than English or without an English language abstract
The two authors independently reviewed the included studies to assess their conformity with the inclusion criteria.

The combinations of search terms resulted in a list of 140 titles (PubMed until 2021and Google scholar). Following the screening of the titles and abstracts by applying the defined inclusion and exclusion criteria, 64 potentially relevant publications were identified in which a full-text analysis was performed. The number of articles that discuss the peri-implant disease were 19 articles. Some of the included articles were not directly related to per-implant disease but were reviewed to better understand the process of peri-implant healthy tissue structures and implant survival and success criteria. Relevant articles discussed the local and systemic etiological factors, bacterial types, crestal bone resorption, implant occlusion and prosthetic types.

Peri-implant health: Peri-implant health requires the absence of clinical signs of inflammation, including no bleeding on probing. Around clinically healthy implants, the mucosa forms a tight seal around the trans-mucosal component of the implant itself, the abutment or the restoration. The soft tissue height around the implant following placement determines the initial probing depth. In most cases, the probing depth associated with peri-implant health should be ≤5.0 mm. As part of the definition, there should be no bone loss greater than the bone level changes which occur after initial bone remodeling immediately following implant placement (Renvert et al., 2018). Healthy peri-implant tissue showed the mucosa covered by stratified squamous epithelium; in addition, a layer of vascular fibrous connective tissue was evident. A few stromal inflammatory cells and rarely some lymphoid cells in the basal layer were observed (Lucarini et al., 2019)
Peri-implant mucositis
This inflammatory response is strictly limited to the soft tissue, with no evidence of progressive bone loss subsequent to the initial remodeling after implant placement, and is known to be reversible (Ramanauskaite et al., 2016). The main clinical sign of this lesion is inflammation of the periimplant mucosa characterized by bleeding on gentle probing (<0>Peri-implantitis
Peri-implantitis was defined by the 2017 Proceedings of the World Workshop as “a plaque-associated pathologic condition occurring in the tissue around dental implants, characterized by inflammation in the periimplant mucosa and subsequent progressive loss of supporting bone.” The authors stated that clinically, the inflammation around implants is manifested as erythema, edema, mucosal enlargement, bleeding on probing (67%) with or without suppuration (94%); with deeper probing depths (PD ≥6 mm at 59%) and bone loss radiographically with a combined supra and infra-osseous configuration progressing circumferentially around implants and faster than around teeth (Schwarz et al., 2018). In the absence of baseline radiographs and probing depths, radiographic bone level ≥3 mm and/or probing depths ≥6 mm in conjunction with profuse bleeding represents peri-implantitis (Renvert et al., 2018). In patients with poor maintenance compliance, it has been observed there is a higher risk of developing peri-implantitis, especially if there is bleeding on probing. It has been shown that for implants presenting bleeding on probing, there was a 24.1% chance of being diagnosed with peri-implantitis (Hashim et al., 2018). In peri-implantitis tissue, adjacent to an ulcerated pocket epithelium, a great inflammatory lesion showing an evident granulation tissue and a dense inflammatory infiltrate was detected (Lucarini et al., 2019) Risk factors of peri-implantitis 1-Patient Related Risk Factors Poor Plaque Control and Peri-Implant Mucositis A patient’s self-performed plaque control is one of the most important factors influencing the implant’s prognosis (Schwarz et al., 2018). A high plaque index was associated with an eightfold increase in susceptibility to peri- implantitis (Kumar et al., 2018). The accumulation of bacterial biofilm on implant and abutment surfaces leads to periimplant inflammation, also known as mucositis, Peri-implantitis is always preceded by a period of mucositis. The two share several risk factors including poor oral hygiene, smoking and sub- mucosal presence of excess cement. Implants diagnosed with mucositis are at risk of developing peri-implantitis (Heitz-Mayfield & Salvi, 2018). However, not all mucositis lesions progress to peri-implantitis, even when present for extensive periods of time (Gualini & Berglundh, 2003)
Periodontal Disease and Microbiological Aspects
The diagnosis, or history, of periodontal disease is the most researched factor associated with peri-implantitis. This is partially attributed to similarities in the subgingival microbiota between the diseased teeth and implants (Ferreira et al., 2018). Current data suggests that peri-implantitis is associated with a specific microbiota resembling that of periodontal lesions, in addition to other microorganisms not commonly related to periodontitis (Faveri et al., 2015).
Nevertheless, it is well-accepted that peri-implantitis consistently presents with marked microbial diversity (Canullo et al., 2015) and that deeper peri-implant pockets exhibit significant microbial alterations and higher levels of dysbiosis (Kroger et al., 2018). Periodontal disease has been strongly associated with peri-implantitis (Saaby et al., 2016). Active periodontitis at the adjacent teeth is further considered a predictor of future peri- implantitis (Kumar et al., 2018). Periodontally compromised patients have
twice the risk of developing peri-implantitis compared with healthy individuals (Ferreira et al., 2018). Moreover, those with a history of generalised aggressive periodontitis are 5 times more prone to implant failure, and 14 times more susceptible to periimplantitis, compared with healthy (Swierkot et al., 2012). Fortunately, successful treatment of periodontal disease prior to implant placement has been shown to lower the risk of peri-implantitis and is therefore considered an essential initial part of the overall treatment plan (Renvert & Quirynen, 2015).
Lack of Maintenance phase
Has been shown to significantly lower the risk of peri-implant biological complications, and a minimum recall interval of 5–6 months has thus been recommended (Monje et al., 2016). Maintenance programs should be tailored to the individual’s specific needs and susceptibility to both periodontal and peri- implant diseases. Factors used for risk assessment include the percentage of BOP, the prevalence of active residual pockets, oral hygiene level, smoking habits and the presence of systemic or genetic conditions (Lang et al., 2015). Individuals with highrisk profiles require three to four annual visits (Armitage & Xenoudi, 2016), and their attendance is detrimental for prevention and early detection of peri-implantitis (Monje et al., 2017). One out of five noncompliant patients are diagnosed with peri-implantitis within 5 years (Rokn et al., 2017), On the other hand, compliance is associated with 86

1-peri-implant disease has multifactorial causes that need to address and prevent them from working together
2-There is a strong relationship between bacterial plaque and the
development of peri-implantitis.
3-plque retention around implant with weak soft tissue attachment in combined with poor hard and soft tissue thickness all work together to initiate per-implant disease.
4-most of delay implants placed in compromised sites (loss of hard and soft tissues), these     sites if not rehabilitated will lead into compromised relation between the prosthesis and the adjacent tissues. This will lead into difficult oral hygiene maintenance.