Peri-implantitis is a disease that cannot be fully described by a single parameter. Biofilm, host immune response, the patient’s systemic condition, local peri-implant factors, and potential material-related aspects all contribute to a complex clinical picture. This is why the PERI-EDU project introduces the concept of SIMREX — an immune-inflammatory response index designed specifically for peri-implant tissue inflammation. Its aim is to integrate selected blood count parameters in order to better capture the systemic inflammatory background of patients with peri-implantitis. At this stage, however, SIMREX remains a conceptual tool that requires further development, validation, and assessment of clinical usefulness.
In implant dentistry, the question increasingly arises whether classical local assessment is sufficient to fully understand peri-implantitis. Clinical examination, probing, assessment of bleeding on probing, pocket depth measurement, bone loss analysis, and evaluation of prosthetic design remain the foundation of diagnostics. Without them, peri-implant tissue diseases cannot be responsibly diagnosed or monitored. At the same time, clinical practice shows that a similar local picture does not always mean a similar disease course.
In some patients, inflammation around the implant develops slowly and can be relatively well controlled. In others, bone loss progresses faster, recurrence is more common, treatment response is less predictable, and prognosis becomes more uncertain. The presence of biofilm alone does not always explain this difference. Increasingly, attention therefore turns to the host: their immune response, systemic inflammation, chronic diseases, metabolism, healing capacity, and susceptibility to tissue destruction.
Against this background, interest in inflammatory markers and indices is growing. Single markers such as CRP, WBC, IL-6, TNF-α, or IL-1β may provide information about inflammatory activity, but they have limited specificity and do not describe the full immunological balance. Aggregated indices such as NLR, PLR, MLR, SII, SIRI, or AISI/PIV attempt to look more broadly — not at one parameter, but at relationships between different elements of the inflammatory and immune response. In the PERI-EDU materials, these groups of indices form the basis for analyzing the systemic inflammatory response associated with peri-implantitis.
SIMREX goes one step further as a project-based concept. According to the assumptions described in the PERI-EDU materials, SIMREX — the Systemic Implant Immune Response Index — is intended to be an aggregated immune-inflammatory response index specific to peri-implant tissue inflammation. Unlike indices adopted from other areas of medicine, its ambition is to better match the context of peri-implantitis. Project materials indicate that SIMREX is based on the integration of blood count parameters such as NEU, MON, PLT, WBC, and RBC.
This is important because most known inflammatory indices were not developed with implant dentistry in mind. SII, NLR, PLR, and SIRI have been analyzed in many inflammatory, metabolic, cardiovascular, and oncological diseases. They may be useful as general tools for describing immune-inflammatory response, but they do not account for the specific nature of peri-implant tissues, implant surfaces, biofilm, osseointegration, bone loss around implants, or the particular character of a disease that develops at the interface between a foreign body and living tissue.
The concept of SIMREX is therefore interesting not because it already provides a ready diagnostic answer, but because it asks the right question: do we need an index for peri-implantitis that is more closely adapted to this disease than general inflammatory indices used in other fields of medicine? If peri-implantitis has its own dynamics, tissue environment, and mechanisms of progression, then the attempt to develop a more specific model of immune-inflammatory assessment seems justified.
In future clinical practice, such a direction could have several potential applications. First, it could support risk assessment in patients with implants, especially those with chronic diseases, a history of periodontitis, diabetes, metabolic syndrome, or other factors influencing inflammatory response. Second, it could help monitor patients whose peri-implantitis progresses more dynamically than would be expected from the local clinical picture alone. Third, it could support research into whether a specific hematological profile is associated with greater susceptibility to peri-implant tissue destruction.
At the current stage, however, the potential of the concept must be clearly separated from its clinical readiness. SIMREX should not be presented as a ready diagnostic test, a screening tool, or an index that independently determines the presence of peri-implantitis. Materials discussing the advantages and limitations of inflammatory indices clearly indicate that SIMREX remains a project-based tool requiring further methodological development and confirmation of its clinical usefulness in large prospective longitudinal studies.
This reservation is crucial. In medicine, it is particularly easy to overestimate the value of a new index when it responds to a real clinical need. And the need is indeed real. Clinicians would like to better predict in which patients inflammation around an implant may progress faster, who requires more intensive monitoring, in whom standard treatment may be less predictable, and when it is worth assessing the patient’s systemic condition more broadly. However, answers to these questions cannot be based on an unvalidated tool.
Therefore, SIMREX should currently be understood primarily as a research and educational direction. It is a research direction because it allows the hypothesis to be tested that a specific configuration of blood count parameters may be relevant in assessing patients with peri-implantitis. It is an educational direction because it helps show students, academic teachers, and clinicians that peri-implant tissue diseases cannot be analyzed only at the level of the implant and biofilm. The patient’s systemic response must also be understood.
In this sense, SIMREX fits well into the main logic of PERI-EDU. The project does not limit itself to describing peri-implantitis as a local complication. It attempts to connect clinical, biological, immunological, and educational knowledge. A project-based index may become one element of this integration — not as a simple number replacing clinical examination, but as a tool that structures thinking about how the patient’s systemic condition may influence the course of disease around an implant.
It is also worth emphasizing that SIMREX should not be set against classical diagnostics. If it proves useful in the future, its place will likely be alongside standard parameters, not instead of them. Assessment of peri-implant tissues, bleeding on probing, probing depth, radiological bone loss, suppuration, implant mobility, prosthetic analysis, history of periodontitis, and systemic factors will remain fundamental. SIMREX could potentially add a biological layer to this assessment — information about how the patient’s organism responds in inflammatory terms.
From the implantologist’s perspective, a particularly interesting question is whether such an index could one day help differentiate patients with a similar clinical picture but different risk of progression. Two patients may have similar probing depths, a similar bone level, and a similar prosthetic design. Yet one may have a stable disease course, while the other develops rapid tissue destruction. If immune-inflammatory indices could help better understand this difference, their clinical value could be significant.
At the same time, it must be remembered that every hematological value is susceptible to confounding. Infections, stress, autoimmune diseases, cancer, medications, metabolic disorders, smoking, age, and general health status may all affect blood count parameters. This also applies to a potential SIMREX index. Future validation would therefore need to include not only patients with peri-implantitis, but also control groups, comorbidities, different stages of disease, treatment course, and changes in the index over time.
Standardization will also be essential. For an index to be useful, it must be clear how it is calculated, under what conditions the parameters are measured, which exclusion factors should be considered, whether a single result or a trend should be assessed, and how it should be interpreted in patients with chronic diseases. Without such standardization, even the most interesting concept will remain difficult to apply in practice.
This does not change the fact that the direction itself is valuable. Implant dentistry increasingly needs tools that help connect the local picture of disease with the biology of the patient. For years, the greatest emphasis was placed on the implant, bone, surgical technique, prosthetic restoration, and biofilm control. Today, the question of the host is becoming increasingly important: how the patient’s organism responds to a chronic inflammatory stimulus and whether that response can be measured in a clinically useful way.
SIMREX may become a symbol of this shift in perspective. Not because it already solves the problem of peri-implantitis diagnostics, but because it moves the discussion toward more integrated, biological, and personalized implant dentistry. It shows that the focus is not only on the implant, but on the patient with an implant — their immunity, inflammatory status, metabolism, and ability to maintain tissue stability.
For PERI-EDU, the significance of SIMREX is therefore twofold. First, it is a research element that may help test new hypotheses concerning systemic immune-inflammatory response in peri-implantitis. Second, it is an educational element that helps explain to students and clinicians why modern implant dentistry should move beyond the simple scheme of “biofilm – inflammation – bone loss” and teach more comprehensive thinking about disease.
The key is to maintain the right proportion. SIMREX is a promising concept, but it requires further research. It may become an important research tool and perhaps, in the future, also a clinical one, but its value must first be confirmed. Today, the greatest strength of the concept is that it organizes the questions that implant dentistry increasingly needs to ask: how to measure the patient’s response, how to combine local and systemic data, and how to recognize biological risk of peri-implantitis progression earlier.
This is why SIMREX deserves a separate place in the educational part of the PERI-EDU project. Not as a ready answer, but as an example of science in progress — from clinical observation, through a research question, to an attempt to develop a tool that may help us better understand patients with peri-implantitis.