- Introduction
Peri-implant diseases, including peri-implant mucositis and peri-implantitis, are biofilm-associated inflammatory conditions affecting the tissues surrounding dental implants. These conditions are common complications post-implant treatment, necessitating accurate diagnosis by clinicians for appropriate treatment.
- Clinical Signs of Peri-Implant Health
Healthy peri-implant soft tissues, or peri-implant mucosa, are achievable with correctly placed implants, well-designed prosthetics, and good patient oral hygiene. Post-rehabilitation, clinicians should measure and record circumferential peri-implant probing depths and soft tissue levels at multiple sites to establish a baseline. It is also advisable to record the width of keratinized peri-implant mucosa.
Healthy peri-implant mucosa resembles healthy gingiva, with no visual signs of inflammation such as erythema or edema. Probing the peri-implant sulcus with a light force should result in no bleeding. Detailed histologic features of healthy peri-implant tissues are further discussed in related literature.
a) Healthy peri-implant mucosa at the implant-supported crown in the upper right first premolar site.
b) Periapical radiograph showing marginal bone levels after remodelling with no loss of supporting bone
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Radiologic Signs of Peri-Implant Health
After implant placement and during the healing period, physiological bone remodeling occurs, establishing peri-implant marginal bone levels at or slightly below the most coronal portion of the endosseous part of the implant. Once the implant is restored, an intra-oral radiograph (periapical or bitewing) should be taken to identify the peri-implant bone levels at the mesial and distal aspects of the implant. This initial radiograph sets the baseline marginal bone levels in a healthy state and serves as a reference for monitoring changes in these levels over time.
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Clinical and Radiologic Signs of Peri-Implant Mucositis
The main criteria for defining peri-implant mucositis are inflammation in the peri-implant mucosa and the absence of continuing marginal peri-implant bone loss. The primary clinical sign of inflammation is bleeding following gentle probing (0.2 N). Additional signs may include redness, swelling, and suppuration (pus).
When peri-implant mucositis is present, there may be a deepening of the peri-implant probing depths compared to baseline measurements taken after the delivery of the implant prosthesis. A radiograph showing no marginal bone loss, alongside these clinical signs, confirms the diagnosis of peri-implant mucositis.
a) Peri-implant mucositis showing inflammation and bleeding on light probing. b) Periapical radiograph showing no loss of supporting boneAccording to the 2023 European Federation of Periodontology S3 clinical practice guideline on the treatment of peri-implant diseases, bleeding on probing (BoP) refers to bleeding at more than one spot around the implant or the presence of a line of bleeding or profuse bleeding at any location.
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Histologic Features of Peri-Implant Mucositis
Peri-implant mucositis results from the accumulation of microbial biofilms around dental implants. Studies show that bacterial biofilms cause an inflammatory response, with biopsies revealing a higher volume of inflammatory cells (T- and B-lymphocytes) compared to healthy tissue. Long-standing peri-implant mucositis shows small, well-defined inflammatory infiltrates and larger lesions than healthy sites.
This condition is reversible; biofilm removal can reverse elevated inflammatory biomarkers, though complete clinical resolution may be difficult, especially with deep implants. Given that peri-implant mucositis can progress to peri-implantitis, prompt treatment and regular re-evaluation are essential to prevent this progression.
- Clinical and Radiologic Signs of Peri-implantitis
Peri-implantitis is characterized by inflammation in peri-implant tissues and progressive bone loss around dental implants.
– Clinical Signs: Diagnosis involves detecting Bleeding on Probing (BoP), increased probing depths (≥6 mm), and peri-implant mucosal recession. Visual inspection may reveal redness, swelling, or a draining sinus. Palpation can detect suppuration from the peri-implant pocket.
– Radiologic Signs: Intra-oral radiographs are essential to confirm peri-implantitis by identifying progressive marginal bone loss. Without previous radiographs, comparison against expected bone levels aids in estimating bone loss.
– Diagnostic Criteria: In the absence of baseline data, peri-implantitis can be diagnosed based on BoP, probing depths ≥6 mm, and marginal bone loss ≥3 mm apical to the implant’s coronal part.
– Progression and Detection: Bone loss typically progresses circumferentially, often within the first three years post-implantation. Early detection requires precise intra-oral radiographs with a 0.5 mm threshold for bone level changes.
– Radiographic Techniques: Standardized intra-oral radiographs are standard for assessing peri-implant bone levels. While CBCT provides detailed facial and oral bone information, it’s not routinely recommended.
Histologic Features of Peri-implantitis and Comparison to Peri-implant Mucositis
Histologic studies of peri-implantitis lesions reveal:
– Peri-implantitis: Biopsies show dense infiltrates of B-cells, neutrophils, and macrophages with increased vascularization. Elevated levels of cytokines (IL1-alpha, TNF-alpha, IL-6) associated with osteoclast activity are noted.
– Comparison: Lesions are larger and more vascularized compared to peri-implant mucositis.
– Animal Studies:In experimental models, inflammatory infiltrates near bone marrow spaces facilitate rapid lesion progression, highlighting the need for early detection and intervention.
– Clinical Implications: Early diagnosis and regular monitoring are crucial for effective management and prevention of peri-implant complications.
Conclusion
Peri-implant mucositis and peri-implantitis are distinct conditions associated with dental implants:
– Peri-implant Mucositis: Inflammation of peri-implant soft tissues (mucosa) characterized by Bleeding on Probing (BoP) without bone loss.
– Peri-implantitis: In addition to BoP, it involves progressive bone loss around implants. Lesions extend beyond pocket epithelium, feature larger inflammatory cell infiltrates, and are rich in plasma cells.
– Progression: While not all cases of mucositis progress to peri-implantitis, mucositis serves as a precursor and risk factor for its development.
– Early Detection: Early onset within three years post-implantation and rapid progression highlight the need for baseline radiographs and periodic probing measurements post-implant therapy. These aid in monitoring changes in bone levels and probing depths over time, facilitating early diagnosis.
– Clinical Assessment: Regular peri-implant probing using a light-force periodontal probe (approximately 0.2 N) is crucial during recall visits to assess implant health status.
– Diagnostic Confirmation:Clinical signs (BoP, increased probing depths) prompt intra-oral radiographs to confirm peri-implantitis based on progressive bone loss.
Monitoring and timely intervention are essential to manage peri-implant diseases effectively and preserve implant longevity.