Progression Of Peri-implantitis Research Articles

Sustained Release of Salicylic Acid for Halting Peri-Implantitis Progression in Healthy and Hyperglycemic Systemic Conditions: A Gottingen Minipig Model.

To develop a peri-implantitis model in a Gottingen minipig and evaluate the effect of local application of salicylic acid poly(anhydride-ester) (SAPAE) on peri-implantitis progression in healthy, metabolic syndrome (MS), and type-2 diabetes mellitus (T2DM) subjects. Eighteen animals were allocated to three groups: (i) control, (ii) MS (diet for obesity induction), and (iii) T2DM (diet plus streptozotocin for T2DM induction). Maxillary and mandible premolars and first molar were extracted. After 3 months of healing, four implants per side were placed in both jaws of each animal. After 2 months, peri-implantitis was induced by plaque formation using silk ligatures. SAPAE polymer was mixed with mineral oil (3.75 mg/μL) and topically applied biweekly for up to 60 days to halt peri-implantitis progression. Periodontal probing was used to assess pocket depth over time, followed by histomorphologic analysis of harvested samples. The adopted protocol resulted in the onset of peri-implantitis, with healthy minipigs taking twice as long to reach the same level of probing depth relative to MS and T2DM subjects (∼3.0 mm), irrespective of jaw. In a qualitative analysis, SAPAE therapy revealed decreased levels of inflammation in the normoglycemic, MS, and T2DM groups. SAPAE application around implants significantly reduced the progression of peri-implantitis after ∼15 days of therapy, with ∼30% lower probing depth for all systemic conditions and similar rates of probing depth increase per week between the control and SAPAE groups. MS and T2DM conditions presented a faster progression of the peri-implant pocket depth. SAPAE treatment reduced peri-implantitis progression in healthy, MS, and T2DM groups.

Single-cell analysis reveals a unique microenvironment in peri-implantitis.

This study aimed to reveal the unique microenvironment of peri-implantitis through single-cell analysis. Herein, we performed single-cell RNA sequencing (scRNA-seq) of biopsies from patients with peri-implantitis (PI) and compared the results with healthy individuals (H) and patients with periodontitis (PD). Decreased numbers of stromal cells and increased immune cells were found in the PI group, which implies a severe inflammatory infiltration. The fibroblasts were found to be heterogeneous and the specific pro-inflammatory CXCL13+ sub-cluster was more represented in the PI group, in contrast to the PD and H groups. Furthermore, more neutrophil infiltration was detected in the PI group than in the PD group, and cell-cell communication and ligand-receptor pairs revealed most neutrophils were recruited by CXCL13+ fibroblasts through CXCL8/CXCL6-CXCR2/CXCR1. Notably, our study demonstrated that the unique microenvironment of the PI group promoted the differentiation of monocyte/macrophage lineage cells into osteoclasts, which might explain the faster and more severe bone resorption in the progression of PI than PD. Collectively, this study suggests a unique immune microenvironment of PI, which may explain the differences between PI and PD in the clinic. These outcomes will aid in finding new specific and effective treatments for PI.

The Critical Role of Pyroptosis in Peri-Implantitis.

Peri-implantitis (PI) is a prevalent complication of implant treatment. Pyroptosis, a distinctive inflammatory programmed cell death, is crucial to the pathophysiology of PI. Despite its importance, the pyroptosis-related genes (PRGs) influencing PI's progression remain largely unexplored. This study conducted histological staining and transcriptome analyze from three datasets. The intersection of differentially expressed genes (DEGs) and PRGs was identified as pyroptosis-related differentially expressed genes (PRDEGs). Functional enrichment analyses were conducted to shed light on potential underlying mechanisms. Weighted Gene Co-expression Network Analysis (WGCNA) and a pyroptotic macrophage model were utilized to identify and validate hub PRDEGs. Immune cell infiltration in PI and its relationship with hub PRDEGs were also examined. Furthermore, consensus clustering was performed to identify new PI subtypes. Protein-protein interaction (PPI) network, competing endogenous RNA (ceRNA) network, mRNA-mRNA binding protein regulatory (RBP) network, and mRNA-drugs regulatory network of hub PRDEGs were also analyzed. Eight hub PRDEGs were identified: PGF, DPEP1, IL36B, IFIH1, TCEA3, RIPK3, NET7, and TLR3, which are instrumental in the PI's progression. Two PI subtypes were distinguished, with Cluster 1 exhibiting higher immune cell activation. The exploration of regulatory networks provided novel mechanisms and therapeutic targets in PI. Our research highlights the critical role of pyroptosis and identifies eight hub PRDEGs in PI's progression, offering insights into novel immunotherapy targets and laying the foundation for advanced diagnostic and treatment strategies. This contributes to our understanding of PI and underscores the potential for personalized clinical management.

Comparative transcriptome analysis of periodontitis and peri-implantitis in human subjects.

Peri-implantitis is similar to periodontitis, but there are some differences. For the effective control of peri-implantitis, it is necessary to clarify its similarities and differences with periodontitis in terms of gene expression. This cross-sectional study included 20 participants (10 healthy subjects and 10 patients with periodontitis and peri-implantitis). Gingival tissue samples (10 healthy, 10 periodontitis, and 10 peri-implantitis tissues) were collected, RNAs were extracted, and RNA sequencing and analysis were performed. Differentially expressed gene (DEG) analysis identified 757 upregulated and 159 downregulated genes common between periodontitis and peri-implantitis. Periodontitis tissues uniquely showed 186 overexpressed and 22 suppressed genes compared with peri-implantitis and healthy tissues, while peri-implantitis had 1974 and 642, respectively. Each common and unique differential gene set showed distinct enriched biological features between periodontitis and peri-implantitis after the pathway enrichment analysis. The expression pattern of selected DEGs focused on the representability of the disease was validated by RT-qPCR. Although periodontitis and peri-implantitis showed common gene expression that was clearly differentiated from healthy conditions, there were also unique gene patterns that were differentially expressed only in peri-implantitis. These findings will help elucidate the mechanisms involved in the progression of peri-implantitis.

Treatment of Peri-implantitis: Fiction or Reality? Part 1: Non-surgical and Surgical Management

Peri-implantitis is a biological complication characterized by an inflammatory process affecting the soft and hard tissues around an osseo-integrated load-bearing implant. Clinically, it results in progressive bone loss, pocket formation, bleeding and/or suppuration and leads to implant loss. Although the main aetiological factor is bacterial biofilms, the clinical presentation and progression of peri-implantitis is exacerbated by several local, systemic and iatrogenic factors. Treatment protocols of peri-implantitis include various decontamination procedures of the exposed implant surface. In this two-part series, we will review the available evidence for the non-surgical and surgical management of peri-implantitis (Part 1), and then we will discuss various modalities for implant surface decontamination (Part 2). CPD/Clinical Relevance: The pre-operative risk identification and management at both patient and site level, early diagnosis and regular supportive peri-implant care are fundamental for long term implant success and survival.

Utilization of Low-Magnitude High-Frequency Vibration (LMHFV) as an Aid in Treating Peri-Implantitis: Case Presentations.

Peri-implantitis is an inflammatory process initiating in the soft tissue and then progressing to the hard tissue surrounding dental implants leading to loss of osseous support and potential loss of the implant if not identified early in the process. This process initiates in the soft tissue, which become inflamed spreading to the underlying bone leading to decreases in bone density with subsequent crestal resorption and thread exposure. In the absence of treatment of the peri-implantitis, the bone loss at the osseous implant interface progresses with inflammatory mediated decrease in the bone density that moves apically, eventually leading to mobility of the implant and its failure. Low-magnitude high-frequency vibration (LMHFV) has been shown to improve bone density, stimulate osteoblastic activity, and arrest progression of peri-implantitis with improvement of the bone or graft around the affected implant with or without surgery as part of the treatment. Two cases are presented using LMHFV to augment treatment.

Absence of Progressive Bone Loss Following Peri-Implantitis Surgical Therapy with Implantoplasty: A Case Series

Background: Peri-implantitis, a bacteria-associated inflammatory disease, is characterized by inflammation of the peri-implant mucosa and progressive loss of the supporting bone, thereby reducing the chances of dental implant survival. The absence of progressive marginal bone loss is crucial for implant success. The aim of this study is to assess the peri-implantitis resolution by measuring the absence of progressive bone loss rate around the implant over a period of one year to more than three years after surgical reconstructive (REC) treatment, apically repositioned flap (ARP) surgery, or combined (COM) treatment of peri-implantitis with implantoplasty. Methods: Peri-implantitis patients, that underwent surgical therapy with implantoplasty and that enrolled in a regular peri-implant supportive care program with a follow up of ≥12 months, were recruited in this study. ARP, REC, or COM surgical therapy was performed depending on the anatomy of the bone defect. For REC and COM groups, intraosseous defects were filled with a bone substitute. The ARP group consisted of an apically positioned flap without osseous surgery. Absence of progressive marginal bone loss was evaluated on radiographs of the treated implants. Results: A total of 57 patients (91 implants) were included. The study occurred over a follow-up period of 12 to 42 months (mean = 24 months). The surgical treatment with implantoplasty yielded an absence of progressive bone loss rate of 96.7% at implant level (100% REC, 98% COM, 92.9% ARP) and 96.5% at patient level. Three implants had to be removed in two patients due to relapse or progression of peri-implantitis. Conclusions: This case series demonstrated that implantoplasty during surgical treatment of peri-implantitis lesions resulted in favorable biological conditions to maintain functional implants with 96.7% of implants that did not show bone loss over time from one year to more than three years.

Progression of experimental peri-implantitis in guided bone regeneration and pristine bone: A preclinical in vivo study.

Guided bone regeneration (GBR) is the most widely used technique for overcoming the deficiency of alveolar bone. However, the progression of peri-implantitis in regenerative and pristine bone sites has not been fully investigated. The aim of this study is to compare experimental peri-implantitis around implants placed in pristine bone and GBR sites. Bilateral mandibular first molars were extracted from six beagle dogs, and standardized horizontal ridge defectwas simultaneously created at predetermined site in unilateral mandible. After 8weeks, guided bone regeneration procedure was conducted at the defect site. After 16 weeks, implants (ϕ 3.6×8.0mm) were placed at both extracted sites. This study included 3 months of active breakdown and another 3 months of spontaneous progression period. Radiographs were taken at each phase and specimens were obtained for histological, immunohistochemical, and polarized light microscopic analysis. Marginal bone loss around implant did not show the significant differences between pristine bone and GBR sites during spontaneous progression period. In immunohistochemical analysis, inflammatory and immune-related cells were predominantly detected in peri-implantitis-affected area rather than unaffected area. In the polarized light microscopic analysis, substantial reductions in the amount and thickness of collagen fibers were observed in peri-implantitis-affected area compared with unaffected tissues. However, there were no significant differences in histological, immunohistochemical, polarized light microscopic outcomes between pristine bone and GBR sites. Previous hard tissue grafting at the implant sites did not affect experimental peri-implantitis and exhibited similar radiographic, histological, immunohistochemical, and polarized light microscopic outcomes compared with those of pristine bone sites.

The Role of Titanium Particles and Ions in the Pathogenesis of Peri-Implantitis

Titanium (Ti) particles and ions have been investigated in recent years as important factors in the pathogenesis of peri-implantitis. However, their role in the pathogenesis is yet to be fully understood. A review of pertinent literature was performed in various databases to determine the current position of Ti particles and ions role in the pathogenesis of peri-implantitis. There are several in vitro, preclinical and clinical published studies that have addressed the role of Ti particles and ions in the pathogenesis of peri-implantitis. These studies explored the effect of Ti particles and ions in the pathogenesis of peri-implantitis with respect to foreign body reaction, cellular response, epigenetic mechanisms, namely DNA methylation, and the oral microbiome. Studies have shown that the release of Ti particles/ions during implant insertion, early healing stages, late healing stages, and treatments during peri-implantitis might contribute to peri-implantitis through different mechanisms, such as foreign body reaction, cellular response, DNA methylation, and shaping the oral microbiome by increasing dysbiosis. However, further studies are needed to elucidate the complex interactions between all these mechanisms and Ti particles/ions in the pathogenesis and progression of peri-implantitis.

Diagnostically significant culturable obligate microorganisms in the development of periimplantitis

BACKGROUND: The urgency of the problem is conditioned by insufficient study of peri-implantitis microbiota, its changes in the dynamics of the process and in the concurrent course with periodontitis.
 AIM: To justify the diagnostically significant cultivated obligate microorganisms involved in the development of inflammatory processes in the area of the placed implants.
 MATERIALS AND METHODS: The study was conducted in the period 20182022. The study involved 127 patients of a private dental clinic in Kirov, Russia. Kirov LLC Dental Clinic aged 35 to 69 years (53.81.9 years). Men made up 48% and women 52%. Biological material from the peri-implant area was examined. Inoculation on dense culture media of biological material with subsequent calculation of microorganism concentration was carried out according to the Gold method of quantitative four-section inoculation. The species identification of the isolated cultures was carried out by MALDI-TOF mass spectrometry using a Vitek-MS bacteriological analyzer (BioMerieux, France).
 RESULTS: Microorganisms obligate anaerobes playing an important role in the development of peri-implantitis were identified in the investigation. Microorganisms that reduce the development of inflammatory changes in periimplantitis, having an inverse correlation between the concentration of microorganisms and the degree of clinical, hygienic and radiological changes in persons with implants, were named periodontal protectors. Microorganisms contributing to the development of pathological processes in the periimplant zone, having a direct correlation relationship between the concentration of microorganisms and the degree of severity of clinical, hygienic and radiological changes periodontopathogens. This was more pronounced in patients with associated periodontitis. The regularity in the increase of frequency and concentration of several pathogens during the progression of peri-implantitis with predominance of micro-organisms in the periimplant area in those with periodontitis was found.
 CONCLUSION: The microbiota of the peri-implant zones has been analyzed by means of the modern bacteriological method mass-spectrometry. On the basis of the study we substantiate the diagnostically significant microorganisms, respectively increasing (periodontopathogens) and reducing (periodontoprotectors) the development of inflammatory changes at periimplantitis.

Integrating Image Analysis and Dental Radiography for Periodontal and Peri-Implant Diagnosis

The recent change in classification of periodontal and peri-implant diseases includes objective evaluation of intra-oral radiographs and quantification of bone loss for disease staging and grading. Assessment of the progression of periodontal disease requires deduction of bone loss longitudinally, and its interpretation as (1) a percentage in relation to tooth root and (2) as a function of the patient's age. Similarly, bone loss around dental implants, after accounting for initial remodeling, is central for determining diagnosis, severity, and progression of peri-implantitis. Bone gain secondary to periodontal regeneration can be measured using standardized dental radiographs and compared to baseline morphology to determine treatment success. Computational image analysis, including machine learning (ML), has the potential to develop and automate quantitative measures of tooth, implant, bone volumes, and predict disease progression. The developed algorithms need to be standardized while considering pre-analytic, analytic, and post-analytic factors for successful translation to clinic. This review will introduce image analysis and machine learning in the context of dental radiography, and expand on the potential for integration of image analysis for assisted diagnosis of periodontitis and peri-implantitis.

Long-term outcomes after peri-implantitis treatment and their influencing factors: a retrospective study.

PurposeThis study aimed to determine the long-term outcomes after peri-implantitis treatment and the factors affecting these outcomes.MethodsThis study included 92 implants in 45 patients who had been treated for peri-implantitis. Clinical data on the characteristics of patients and their implants were collected retrospectively. The change in the marginal bone level was calculated by comparing the baseline and the most recently obtained (≥3 years after treatment) radiographs. The primary outcome variable was progression of the disease after the treatment at the implant level, which was defined as further bone loss of >1.0 mm or implant removal. A 2-level binary logistic regression analysis was used to identify the effects of possible factors on the primary outcome.ResultsThe mean age of the patients was 58.7 years (range, 22–79 years). Progression of peri-implantitis was observed in 64.4% of patients and 63.0% of implants during an observation period of 6.4±2.7 years (mean±standard deviation). Multivariable regression analysis revealed that full compliance to recall visits (P=0.019), smoking (P=0.023), placement of 4 or more implants (P=0.022), and marginal bone loss ≥4 mm at baseline (P=0.027) significantly influenced the treatment outcome.ConclusionsThe long-term results of peri-implantitis treatment can be improved by full compliance on the part of patients, whereas it is impaired by smoking, placement of multiple implants, and severe bone loss at baseline. Encouraging patients to stop smoking and to receive supportive care is recommended before treatment.

Impact of Home and Professional Care on Laser-Assisted Management of Peri-implant Complications: A Case Report

This case report emphasizes how home and professional care can impact clinical outcomes following nonsurgical mechanical therapy with the adjunctive use of a diode laser to treat failing implants. Localized severe peri-implant disease was diagnosed in a patient who was susceptible to periodontal disease, not compliant, and did not accept the surgical approach. A cause-related, diode laser-assisted, nonsurgical treatment was therefore implemented, according to a dedicated protocol, in four closely scheduled appointments. The patient's oral hygiene skills became extremely effective. She then adhered to a bimonthly maintenance protocol in the first follow-up year and quarterly in the subsequent year. Bone remineralization was detected on comparative periapical radiographs 2 years after the diagnosis of peri-implantitis. At the 2-year observation, the patient's high standard of home care and dedicated maintenance arrested the progression of peri-implantitis and yielded clinical and radiographic improvements following nonsurgical mechanical therapy with adjunctive repeated application of a diode laser.

Clinical evaluation of periodontal pathogen levels by real-time polymerase chain reaction in peri-implantitis patients

ObjectiveThe mechanisms underlying the onset and progression of peri-implantitis are similar to those of periodontitis, and the causative bacteria are believed to similar. Previous studies support an association between peri-implantitis and periodontal pathogen. Thus, we investigated the bacterial flora of peri-implantitis patients in comparison to those of healthy implant and periodontitis patients.Materials and methodsIn total, 70 patients visiting Tokyo Dental College Chiba Hospital were divided into four groups: healthy, periodontitis, healthy implant, and peri-implantitis. For each group, the following five periodontal pathogens were detected using real-time polymerase chain reaction: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Prevotella intermedia.ResultsThe average copy number of total bacteria was significantly higher in the periodontitis group than in the other groups. P. gingivalis was detected in the periodontitis and peri-implantitis groups at levels as high as 18.92% and 12.29%, respectively, and P. intermedia was found in the peri-implantitis group at a rate of 2.06%. Nevertheless, periodontal pathogens were generally detected at lower levels in the peri-implantitis group than in the periodontitis group.ConclusionWe found lower bacterial counts in the peri-implantitis group relative to the periodontitis group. Our results suggest that the peri-implant tissue is less resistant to bacteria, so even a small number of bacteria can be a risk factor for peri-implantitis and the causative agent of peri-implantitis can be bacteria other than periodontal pathogen.

Peri-implantitis: Summary and consensus statements of group 3. The 6th EAO Consensus Conference 2021.

To evaluate the influence of implant and prosthetic components on peri-implant tissue health. A further aim was to evaluate peri-implant soft-tissue changes following surgical peri-implantitis treatment. Group discussions based on two systematic reviews (SR) and one critical review (CR) addressed (i) the influence of implant material and surface characteristics on the incidence and progression of peri-implantitis, (ii) implant and restorative design elements and the associated risk for peri-implant diseases, and (iii) peri-implant soft-tissue level changes and patient-reported outcomes following peri-implantitis treatment. Consensus statements, clinical recommendations, and implications for future research were discussed within the group and approved during plenary sessions. Data from preclinical in vivo studies demonstrated significantly greater radiographic bone loss and increased area of inflammatory infiltrate at modified compared to non-modified surface implants. Limited clinical data did not show differences between modified and non-modified implant surfaces in incidence or progression of peri-implantitis (SR). There is some evidence that restricted accessibility for oral hygiene and an emergence angle of >30combined with a convex emergence profile of the abutment/prosthesis are associated with an increased risk for peri-implantitis (CR). Reconstructive therapy for peri-implantitis resulted in significantly less soft-tissue recession, when compared with access flap. Implantoplasty or the adjunctive use of a barrier membrane had no influence on the extent of peri-implant mucosal recession following peri-implantitis treatment (SR). Prosthesis overcontouring and impaired access to oral hygiene procedures increases risk for peri-implantitis. When indicated, reconstructive peri-implantitis treatment may facilitate the maintenance of post-operative peri-implant soft-tissue levels.

What is the influence of implant surface characteristics and/or implant material on the incidence and progression of peri-implantitis? A systematic literature review.

To answer the focused question, 'In animals or patients with dental implants, does implant surface characteristics and/or implant material have an effect on incidence and progression of peri-implantitis?' Pre-clinical in vivo experiments on experimental peri-implantitis and clinical trials with any aim and design, and ≥5years follow-up, where the effect of ≥2 different type of implant material and/or surface characteristics on peri-implantitis incidence or severity, and/or progression, implant survival or losses due to peri-implantitis, and/or marginal bone levels/loss was assessed. Meta-analyses based on data of pre-clinical experiments, using the ligature induced peri-implantitis model in the dog, indicated that after the spontaneous progression phase implants with a modified surface showed significantly greater radiographic bone loss (effect size 0.44mm; 95%CI 0.10-0.79; p=.012; 8 publications) and area of infiltrated connective tissue (effect size 0.75mm2 ; 95%CI 0.15-1.34; p=.014; 5 publications) compared to non-modified surfaces. However, in 9 out of the 18 included experiments, reported in 25 publications, no significant differences were shown among the different implant surface types assessed. Clinical and/or radiographic data from 7605 patients with 26,188 implants, reported in 31 publications (20 RCTs, 3 CTs, 4 prospective cohort, and 4 retrospective studies; 12 with follow-up ≥10years), overall did not show significant differences in the incidence of peri-implantitis, when this was reported or could be inferred, among the various implant surfaces. In general, high survival rates (90-100%) up to 30years and no clinically relevant differences in marginal bone loss/levels, merely compatible with crestal remodelling, were presented for the various implant types. Pre-clinical in vivo experiments indicate that surface characteristics of modified implants may have a significant negative impact on peri-implantitis progression, while clinical studies do not support the notion that there is a difference in peri-implantitis incidence among the various types of implant surfaces. No assumptions can be made regarding the possible impact of implant material on incidence and/or peri-implantitis progression due to limited information.

Two- and ten-year follow-up of patients responding and non-responding to the surgical treatment of peri-implantitis: A retrospective evaluation.

To report a follow-up of patients following the surgical anti-infective treatment of peri-implantitis and to identify possible risk indicators for the progression of disease during supportive peri-implant therapy. Following peri-implant surgery, 41 patients (213 implants) were enrolled in a supportive peri-implant therapy. At the 2-year follow-up, two groups of patients were identified, with or without residual peri-implant pockets (responding and non-responding group). Eighteen patients (85 implants) of the non-responding group were followed for further 8years. At the 2-year examination, 73 of the 117 treated implants (62.4%) presented healthy peri-implant condition, while 44 (37.6%) presented persisting peri-implantitis associated with substantial bone loss before treatment. The 10-year examination of the non-responding group revealed that 1) 84% of the implants that regained health following surgery remained healthy during the entire observation period; 2) 66% of the implants with residual pockets following surgery maintained stable peri-implant condition; and 3) 29% of all treated implants showed disease progression, and 11 of those were extracted. Presence of pockets at 3-4 sites of the implants was identified as risk indicator for progression of peri-implantitis. The peri-implant health achieved following therapy was maintained for most of the implants during the follow-up. Residual pockets were a frequent finding at implants with substantial bone loss before treatment. Presence of pockets around the entire circumference of the implants resulted as a risk indicator for further disease progression. The probability of progression of peri-implant disease increased with increased observation time.

Differences in the progression of experimental peri-implantitis depending on the implant to abutment connection.

The aim was to evaluate the rate of bone loss progression during experimentally induced peri-implantitis using two different implant-abutment connections in implants with identical surface topography. Forty-eight Regular Neck tissue-level SLA implants with a matching implant to abutment connection (TL) and 36 bone-level SLA implants with a switching platform implant to abutment connection (BL) were subjected to experimental peri-implantitis in two independent in vivo pre-clinical investigations. Experimental peri-implantitis was induced by means of silk ligatures during 3 months (induction phase), and followed for one extra month without ligatures (progression phase). Radiographic and clinical outcomes were evaluated longitudinally along both studies and subsequently compared between experiments. During the induction phase, radiographic bone loss was significantly higher in implants with matched abutments compared with those with platform switching connections (2.65 ± 0.66 mm vs 0.84 ± 0.16 mm, respectively, p = 0.001). During the progression phase, both types of implant-abutment connection exhibited similar rates of radiographic bone loss. Similar outcomes were observed clinically. A platform switching connection resulted in a more benign development of peri-implantitis during the experimental induction phase of the disease. These differences, however, disappeared once the ligatures were removed (progression phase). Influence of the implant-abutment connection in peri-implantitis progression may be relevant when considering implant selection in the moment of placement. In this sense, platform switching abutment demonstrated less peri-implantitis development when compared to implant matching connection.

Efficacy of Local Minocycline Agents in Treating Peri-Implantitis: An Experimental In Vivo Study in Beagle Dogs.

Background: Local delivery agents (LDA) have the advantage of delivering the antibiotics at high concentrations to the targeted sites. However, the constant flow of gingival crevicular fluids and saliva may restrict their efficacy. Therefore, the drug sustainability and pharmacodynamic properties of any proposed LDA should be evaluated. Methods: Four dental implants were placed unilaterally in the edentulous mandible of six beagle dogs. Peri-implantitis were experimentally induced using silk-ligatures. Each implant was randomly allocated to receive one of the following four treatments: (i) MC (Chitosan-alginate (CA) minocycline), (ii) MP (CA-without minocycline), (iii) PG (Polyacrylate-glycerin minocycline), and (iv) Control (mechanical debridement only). Mechanical therapies and LDAs were administered into the gingival sulcus two times at a 4-week interval. Drug sustainability as well as clinical, radiographical, and immunohistochemical (IHC) analyses were conducted to evaluate the efficacies of treatments. Results: Reduced mean probing depth was observed in all of the test groups after the second delivery. A minimal marginal bone level change was observed during the treatment period (MP (−0.06 ± 0.53 mm) to PG (−0.25 ± 0.42 mm)). The distribution of IHC cell marker analysis of all targeted antibodies ranged from 6.34% to 11.33%. All treatment outcomes between the test groups were comparable. A prolonged retention of LDA was observed from CA microspheres (MC and MP) at both administrations (p < 0.017) and prolonged sustainability of bacteriostatic effect was observed from MC compared to PG after the second administration (p < 0.05). Conclusions: Prolonged retention of CA microspheres was observed and the longer bacteriostatic effect was observed from the MC group. Mechanical debridement with adjunct LDA therapy may impede peri-implantitis progression, however, prolonged drug action did not lead to improved treatment outcome.

Influence of restorative design on the progression of peri-implant bone loss: A retrospective study.

Clinical data on the restorative designs affecting the early progression of peri-implantitis are scarce. The aim of this retrospective study was to evaluate the influence of several restorative factors (e.g., restoration emergence angle, and internal screw length/diameter) on the marginal bone loss around implants with peri-implantitis. Implants diagnosed with peri-implantitis having 1- (T1) and 2-year (T2) follow-ups were included. In addition, within 6 months pre-diagnosis (Tb), all cases required to have full documentation in which no evidence of peri-implantitis was not indicated. Changes in marginal bone levels (MBLs) from Tb to T1 and from T1 to T2 were evaluated. The effect of several variables on MBLs changes was assessed via univariate and multivariate generalized estimating equations. Eighty-three bone-level implants from 65 patients were selected. The mean follow-up before peri-implantitis diagnosis was 99.47 ± 47.93 months. The radiographic mean marginal bone loss was 1.52 ± 1.33mm (Tb to T1) and 0.58 ± 0.52mm (T1 to T2). Restoration emergence angle and frequency of maintenance visits significantly affected MBLs from Tb to T1. Besides, 66.3% of the included implants' bone levels were in a zone within 1mm of the apical end of the internal screw at T1 and remained in this zone during the second follow-up year. Significant marginal bone loss occurred in the early post-diagnosis period of peri-implantitis, which could be affected by the restoration emergence angle. Peri-implant MBLs were frequently located in a zone within 1mm of the apical end of the internal screw.