Machine learning-assisted immune profiling stratifies peri-implantitis patients with unique microbial colonization and clinical outcomes.

Rationale: The endemic of peri-implantitis affects over 25% of dental implants. Current treatment depends on empirical patient and site-based stratifications and lacks a consistent risk grading system. Methods: We investigated a unique cohort of peri-implantitis patients undergoing regenerative therapy with comprehensive clinical, immune, and microbial profiling. We utilized a robust outlier-resistant machine learning algorithm for immune deconvolution. Results: Unsupervised clustering identified risk groups with distinct immune profiles, microbial colonization dynamics, and regenerative outcomes. Low-risk patients exhibited elevated M1/M2-like macrophage ratios and lower B-cell infiltration. The low-risk immune profile was characterized by enhanced complement signaling and higher levels of Th1 and Th17 cytokines. Fusobacterium nucleatum and Prevotella intermedia were significantly enriched in high-risk individuals. Although surgery reduced microbial burden at the peri-implant interface in all groups, only low-risk individuals exhibited suppression of keystone pathogen re-colonization. Conclusion: Peri-implant immune microenvironment shapes microbial composition and the course of regeneration. Immune signatures show untapped potential in improving the risk-grading for peri-implantitis.

Classification and Clinical Management of Retrograde Peri-implantitis Associated with Apical Periodontitis: A Proposed Classification System and Case Report.

Biological complications involving dental implants include peri-implant diseases such as peri-implant mucositis and peri-implantitis. The latter presents with progressive bone loss from the alveolar crest in a coronal apical direction. However, a separate disease entity termed retrograde peri-implantitis (RPI), which presents with progressive bone loss at the periapex of the implant, also exists and may be of particular interest to endodontists because it typically presents with periapical pathology of both the implant and adjacent tooth or at a site that previously housed an endodontically treated tooth. The reported prevalence of retrograde peri-implantitis is 0.26%, which is much lower than the prevalence of marginal peri-implantitis; however, its incidence increases to 7.8% when teeth adjacent to the implant exhibit an endodontic infection. It is positively correlated with a shorter distance between the implant and the adjacent tooth and a shorter time elapsed from the endodontically treated adjacent tooth to implant placement. This case report describes a patient diagnosed with an RPI lesion (RPI) associated with an adjacent endodontically treated tooth with a persistent periapical radiolucent lesion. The diagnosis, possible etiology, and management of the RPI lesion is thoroughly reported including follow-up visits showing complete resolution after subsequent periodontal and endodontic therapy. Endodontic evaluation of teeth adjacent to the implant site should be performed for primary prevention of RPI. Proper classification of RPI will aid in determining the course of treatment; class 1 and 2 cases require endodontic therapy of the involved teeth for healing to occur.

A Classification System for Peri-implant Diseases and Conditions.

Peri-implant bone levels are influenced by pathologic and nonpathologic conditions. The understanding of peri-implant disease has evolved over the past several decades, and the classification of peri-implantitis has been limited to descriptions of disease progression or those involving soft and/or hard tissues (peri-implant mucositis or peri-implantitis). However, no classification system has been established based on etiology. The objective of this study was to identify various etiologies for peri-implantitis and to establish a classification system based on the pathogenesis. The results indicate that the majority of bone loss was related to biofilm, followed by iatrogenic factors, exogenous irritants, absence of keratinized tissue, and extrinsic pathology. The proposed classification system will allow the clinician to properly diagnose peri-implant diseases in relation to etiology. These conditions may respond differently to applied therapies.

Immediate loading of mandibular overdentures supported by one-piece, direct metal laser sintering mini-implants: a short-term prospective clinical study.

BACKGROUND: Only a few studies have dealt with immediately loaded, unsplinted mini-implants supporting ball attachment-retained mandibular overdentures (ODs). The aim of this study is to evaluate treatment outcomes of ball attachment-retained mandibular ODs supported by one-piece, unsplinted, immediately loaded, direct metal laser sintering (DMLS) mini-implants. METHODS: Over a 4-year period (2009 to 2012), all patients referred to the Dental Clinic, University of Varese, and to a private practice for treatment with mandibular ODs were considered for inclusion in this study. Each patient received three or four DMLS mini-implants. Immediately after implant placement, a mandibular OD was connected to the implants. At each annual follow-up session, clinical and radiographic parameters were assessed, including the following outcome measures: 1) implant failures; 2) peri-implant marginal bone loss; and 3) complications. Statistical analysis was conducted using a life-table analysis. RESULTS: A total of 231 one-piece DMLS mini-implants were inserted in 62 patients. After 4 years of loading, six implants failed, giving an overall cumulative survival rate of 96.9%. The mean distance between the implant shoulder and the first visible bone-to-implant contact was 0.38 ± 0.25 and 0.62 ± 0.20 mm at the 1- and 4-year follow-up examinations, respectively. An incidence of 6.0% of biologic complications was reported; prosthetic complications were more frequent (12.9%). CONCLUSIONS: Within the limits of this study, it can be concluded that the immediate loading of one-piece, unsplinted, DMLS titanium mini-implants by means of ball attachment-supported mandibular ODs is a successful treatment procedure. Long-term follow-up studies are needed to confirm these results.

Single crowns in the resorbed posterior maxilla supported by either 6-mm implants or by 11-mm implants combined with sinus floor elevation surgery: a 1-year randomised controlled trial.

PURPOSE: The aim of this randomised controlled trial was to assess the clinical performance of single crowns in the posterior maxilla supported by either 6-mm or 11-mm implants combined with maxillary sinus floor elevation. MATERIALS AND METHODS: 41 consecutive patients with one missing premolar or molar in the posterior maxilla and with an estimated bone height of 6 to 8 mm in that area were included. Each patient was randomly allocated to one of the two treatment groups, namely to receive an 11-mm implant (Osseo Speed 4.0 S, Dentsply Implants, Mölndal, Sweden) in combination with maxillary sinus floor elevation surgery or to receive a 6-mm implant (Osseo Speed 4.0 S) without any grafting. After a 3-month osseointegration period, all implants were restored with custom-made titanium abutments and cemented zirconia-based porcelain crowns. Outcome measures were: implant survival; radiographic bone changes; plaque accumulation; bleeding tendency; peri-implant inflammation; presence of dental calculus; biological and technical complications; and patients' satisfaction. Clinical and radiographic examinations were performed at placement of the crown and 12 months thereafter. Patients' satisfaction was scored before treatment and after 12 months of functioning of the crown. RESULTS: One patient of the 11 mm implant group died during the follow-up. No implant failed and no biological or technical complications occurred. From loading to the 12 months follow-up, no difference was found in mean marginal bone changes between the groups (bone resorption in both groups 0.1 ± 0.3 mm). Clinical items revealed very healthy peri-implant soft tissues in both groups. Patients' satisfaction scores were high in both groups. CONCLUSIONS: 6-mm implants and 11-mm implants combined with sinus floor elevation surgery are equally successful to support a single crown in the resorbed posterior maxilla after 1-year follow-up.

Peri-implantitis diagnosis and treatment by New Zealand periodontists and oral maxillofacial surgeons.

OBJECTIVES: This study aimed to investigate the understanding, diagnosis and management of peri-implantitis by New Zealand periodontists and oral maxillofacial surgeons (OMFS). DESIGN: Telephone interviews (in combination with a postal and electronic survey) were conducted of all 25 periodontists and 32 OMFS listed as specialists on the New Zealand Dental Register. A seven item multi-choice and short answer questionnaire was used to investigate: their definition of peri-implantitis; the number of annual referrals received in their practice for this condition; their diagnostic, preventive and treatment strategies for peri-implantitis; and their perception of the role of general dental practitioners in its management. RESULTS: The participation rate was 84.6%. Most respondents defined peri-implantitis as a disease of multifactorial aetiology that leads to destruction of the bone supporting an implant. The average number of cases seen annually differed between periodontists (11 cases/year) and OMFS (4 cases/year). The criteria used by the respondents to diagnose peri-implantitis included increased probing depths and radiographic evidence of bone loss. Each type of specialist used mechanical debridement for treatment, but a higher proportion of OMFS performed surgical procedures as treatment. The prevention strategies used smoking cessation advice and ensuring good plaque control. All respondents agreed that peri-implantitis is an important disease that can lead to implant failure, and all acknowledged the role of general dental practitioners in diagnosis, referral for treatment and long-term implant maintenance. CONCLUSION: The definition, diagnostic criteria and management strategies used by New Zealand specialists are generally consistent with those found in the literature. No evidence-based, gold standard treatment protocol for peri-implantitis has been identified in the literature, and New Zealand specialists use a range of treatment modalities.

Coated vs uncoated implants: bone defect configurations after progressive peri-implantitis in dogs.

In this study, hydroxyapatite coated vs uncoated implants were used to evaluate the type and dimensions of bone defects after progressive peri-implantitis in dogs. Thirty-two dental implants with 4 different surfaces-machined (M), sandblasted acid-etched (SA), 1-µm thin sputter hydroxyapatite (HA)-coated (S), and plasma-sprayed HA-coated (P)-were inserted into the mandibles of 4 beagle dogs after extracting all mandibular premolars. Experimental peri-implantitis was induced after 3 months using ligature to allow for plaque accumulation. After 4 months, ligatures were removed and plaque accumulation continued for 5 months (progression period). The open flap surgery demonstrated 3 patterns of peri-implantitis bone defect: (1) Class I defect: represented as circumferential intra-alveolar bone loss; (2) Class II defect: circumferential intra-alveolar defect with supra-alveolar bone loss exposing the implant surface; and (3) Class III defect: represented as circumferential intra-alveolar defect with supra-alveolar bone loss and buccal dehiscence. Class I was the most frequent (62.5%) defect pattern around implant types M, SA, and S; while implant type-P showed a recurring majority of Class II (62.5%). Comparison among the 4 implant groups revealed a significant defect width (DW) in implant type-P relative to other types (P < 0.01). However, no statistically significant differences were noted for defect depth (DD) (P > 0.05). We concluded that the shape and size of peri-implantitis bone defects were influenced by the type and thickness of the HA coat together with the quantity of the available peri-implant bone. Plasma-sprayed HA-coated implants showed larger peri-implant defects than did thin sputter HA-coated implants.

An insight into peri-implantitis: a systematic literature review.

AIM: This systematic literature review was performed to establish a definition of peri-implantitis, what makes a patient more susceptible to peri-implantitis, the signs and symptoms of peri-implantitis (including radiographic findings), treatment options for peri-implantitis, and to investigate what constitutes a suitable oral hygiene regime. METHOD: A systematic literature review and analysis of publications included in PubMed (articles published between 1998 and 2003; English language; search terms "peri-implantitis"; "mucositis"; "partially edentulous"; "preventative maintenance"; "peri-implantitis and plaque control"; "tissue augmentation"; "diet maintenance of peri-implantitis"; "oral hygiene instruction for implants") was performed to identify papers providing information about peri-implantitis. Separately sourced publications with peri-implantitis related titles and abstracts were reviewed and analysed. The set criteria for inclusion were peer-reviewed articles. Of 53 papers identified, 23 were included for systematic review. RESULTS: Analysis of the papers revealed that patients with implants are more susceptible to developing peri-implantitis than are patients with natural teeth to developing periodontal disease. This is due to the varied peri-implant tissue that surrounds the implant in comparison with the tissue that surrounds a natural tooth. If active periodontal disease is present, peri-implantitis may also develop; however, other secondary factors may also need to be present for this to occur. CONCLUSION: A comprehensive periodontal examination should be carried out prior to implant surgery. The patient should be informed of the necessity of regular maintenance following implant surgery and the prerequisite of maintaining a comprehensive oral hygiene regime to avoid peri-implantitis.

Treatment outcome in patients with peri-implantitis in a periodontal clinic: a retrospective study.

BACKGROUND: The number of placed implants has grown during the past decade, and the prevalence of peri-implantitis has increased. The purpose of the present study is to investigate the treatment outcome of peri-implantitis and to identify factors influencing the treatment success rate. METHODS: The study was conducted as a retrospective longitudinal study on a referral population. The material included 382 implants with peri-implantitis in 150 patients. Peri-implantitis was defined as presence of pocket depths ≥5 mm, bleeding at probing and/or suppuration, and the presence of implant radiographic bone loss ≥3 mm or bone loss comprising at least three threads of the implant. Variance analyses, χ(2) analyses, and logistic regression analysis were used for data analyses. RESULTS: The mean age of the participants at baseline was found to be 64 years (range: 22 to 87 years). The mean ± SD follow-up time was 26 ± 20 months, and the mean time between implant installation and baseline was 6.4 years (range: 1 to 20 years). Periodontal flap surgery with osteoplasty was the most common type of therapy (47%), and regenerative surgery procedures with bone substitute materials were chosen in 20% of the cases. The mean success rate at patient level was 69%. The results of the logistic regression analyses showed that the success rate was significantly lower for individuals with the diagnosis of severe periodontitis, severe marginal bone loss around the implants, poor oral hygiene, and low compliance. CONCLUSION: The effectiveness of the peri-implantitis therapy was impaired by severe periodontitis, severe marginal bone loss around the implants, poor oral hygiene, and low compliance.

The evaluation of bacterial flora in progress of peri-implant disease.

BACKGROUND: Cumulative interceptive supportive therapy (CIST) is currently used as a guideline for treating peri-implant diseases. The objectives of this study were to determine the detection rate and measure the number of periodontopathic bacteria in lesions of different CIST levels and thereby characterize peri-implant disease from a bacteriological viewpoint. METHODS: This study included 105 patients who had both residual natural teeth and implants with peri-implant disease. A total of 105 implants were divided into levels A, B, C and D according to the CIST classification. Bacterial samples were collected from peri-implant pockets and four periodontopathic bacteria were measured by PCR and PCR-Invader assay. RESULTS: The number of periodontopathic bacteria increased in line with CIST level, and the detection rate was also associated with CIST level. However, no difference was found in the bacterial detection rate of P. gingivalis and T. denticola between CIST-B and CIST-C. There was a higher detection rate of all periodontopathic bacteria for CIST-D. CONCLUSIONS: The number of periodontopathic bacteria and detection rate increased as peri-implant disease advanced. However, there were no major differences in the detection rate between CIST-B and CIST-C. On the other hand, a higher detection rate of periodontopathic bacteria was seen for CIST-D.