TNF-α TGF-β2 and IL-1β levels in gingival and peri-implant crevicular fluid before and after de novo plaque accumulation

Mass spectrometry-based proteomic applications in dental implants research

Dental implants have been established as successful treatment options for missing teeth with steadily increasing demands. Today, the primary areas of research in dental implantology revolve around osseointegration, soft and hard tissue grafting as well as peri-implantitis diagnostics, prevention, and treatment. This review provides a comprehensive overview of the current literature on the application of MS-based proteomics in dental implant research, highlights how explorative proteomics provided insights into the biology of peri-implant soft and hard tissues and how proteomics facilitated the stratification between healthy and diseased implants, enabling the identification of potential new diagnostic markers. Additionally, this review illuminates technical aspects, and provides recommendations for future study designs based on the current evidence.

Peri-implantitis as the consequence of errors in implant therapy

Peri-implantitis is a plaque-associated pathologic condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. It is a highly prevalent disease, as extensively estimated by large-population, cross-sectional studies. As peri-implant diseases represent opportunistic infections, it is reasonable to assume that nonideal conditions, local and/or general, may favor the progression of peri-implant inflammation. Some of these conditions could be a result of poor planning and/or inadequate execution of any step of the entire process treatment. This article describes the major possible factors in implant therapy that may lead to peri-implantitis. For some of these (ie, inappropriate patient selection, insufficient periodontal therapy, lack of diagnosis and management of peri-implant mucositis, erratic supportive peri-implant/periodontal therapy) there is a good level of evidence, whereas for others (ie, wrong implant placement, poor postoperative care, inadequate prosthetic reconstruction, lack of assessment and management of peri-implant soft-tissue deficiencies) there is little scientific evidence. More research is therefore needed to clearly identify the errors and/or complications possibly leading to peri-implantitis, particularly over the long term.

Do the progression of experimentally induced gingivitis and peri-implant mucositis present common features? A systematic review of clinical human studies

This systematic review evaluated the features of the progression of experimentally induced gingivitis and peri-implant mucositis in humans. Included were studies that evaluated clinical, immunological, or microbiological responses between experimentally induced gingivitis and peri-implant mucositis in periodontally healthy patients. A total of 887 articles were initially identified, but only 12 were included in the final analysis. Implants accumulate less biofilm and suffer the most heterogeneous alterations in the microbiota, in the abstinence of oral hygiene, compared with the tooth. Interestingly, although dental implants presented less biofilm accumulation, the peri-implant mucosa showed a more exacerbated clinical response than the gingival tissue. The risk of bias of the selected studies was moderate to low, with one study presenting serious risk. The progression events of peri-implant mucositis were similar to those of experimental gingivitis but led to a different host response. This review was registered in the PROSPERO database CRD420201 123360.

Network pharmacology combined with GEO database identifying the mechanisms and molecular targets of Polygoni Cuspidati Rhizoma on Peri-implants

Peri-implants is a chronic disease leads to the bone resorption and loss of implants. Polygoni Cuspidati Rhizoma (PCRER), a traditional Chinese herbal has been used to treat diseases of bone metabolism. However, its mechanism of anti-bone absorption still remains unknown. We aimed to identify its molecular target and the mechanism involved in PCRER potential treatment theory to Peri-implants by network pharmacology. The active ingredients of PCRER and potential disease-related targets were retrieved from TCMSP, Swiss Target Prediction, SEA databases and then combined with the Peri-implants disease differential genes obtained in the GEO microarray database. The crossed genes were used to protein–protein interaction (PPI) construction and Gene Ontology (GO) and KEGG enrichment analysis. Using STRING database and Cytoscape plug-in to build protein interaction network and screen the hub genes and verified through molecular docking by AutoDock vina software. A total of 13 active compounds and 90 cross targets of PCRER were selected for analysis. The GO and KEGG enrichment analysis indicated that the anti-Peri-implants targets of PCRER mainly play a role in the response in IL-17 signaling, Calcium signaling pathway, Toll-like receptor signaling pathway, TNF signaling pathway among others. And CytoHubba screened ten hub genes (MMP9, IL6, MPO, IL1B, SELL, IFNG, CXCL8, CXCL2, PTPRC, PECAM1). Finally, the molecular docking results indicated the good binding ability with active compounds and hub genes. PCRER’s core components are expected to be effective drugs to treat Peri-implants by anti-inflammation, promotes bone metabolism. Our study provides new thoughts into the development of natural medicine for the prevention and treatment of Peri-implants.

Success of dental implant influenced by abutment types and loading protocol

Background:

Dental implants are considered better, latest, and most advanced technique of teeth replacement in present times with more teeth loss and increased related concerns.

Aims:

The present clinical trial was carried out to assess marginal bone loss and implant failure in immediate and delayed loading implants. The study also evaluated healing using Polymerase Chain Reaction (PCR) and the effect of risk factors on marginal bone loss.

Materials and Methods:

The 44 subjects were randomly divided into two groups with immediate loading and delayed loading protocols. Various soft-tissue parameters were seen clinically. Quantitative PCR was done to detect biomarkers. The collected data were subjected to statistical evaluation with a level of significance at P < 0.05 and the results were formulated.

Results:

Concerning marginal bone loss, it was seen that for delayed loading, the bone loss at the implant level was 1.52 ± 0.14, 0.19 ± 0.11, and 0.40 ± 0.12, respectively, at placement, 1 and 2 years. Plaque and mucosal bleeding scores were low at the time of placement with respective values of 0.96 ± 0.12 and 28.42 ± 3.15 for the delayed loading group and 0.98 ± 0.11 and 30.24 ± 3.15 for the immediate loading group. Tartrate-resistant acid phosphatase (TRAP) showing remodeling was high at 3 months in delayed loading (13.3 ± 8.5). Alkaline Phosphatase (ALP) was highest in delayed loading at 3 months (25.2 ± 7.7) and immediate loading at 2 days (32.6 ± 13).

Conclusion:

Both immediate loading and delayed loading implants show similar results in terms of bone loss, soft-tissue parameters, and biomarkers in sulcular fluids with relatively few and manageable complications.

Is It Safe To Reuse Healing Abutments? An Experimental Study on IL-1β and TNF-α Cytokine Levels in Peri-Implant Crevicular Fluid

PURPOSE

To compare pro-inflammatory cytokine levels in the peri-implant crevicular fluid (PICF) in unused and reused healing abutments.

MATERIALS AND METHOD

This study was a controlled randomized, double-blind clinical trial. Seventy-two patients who met the inclusion criteria were divided into two groups. After one-stage implant placement, in group A, an unused healing abutment, and in group B, a reused healing abutment, was connected to the implant fixture. After 2 months, clinical measurements for keratinized gingiva (KG), plaque index (PI), and bleeding index (BI) (Ainamo and Bay) were taken, and PICF sampling was performed to evaluate pro-inflammatory IL-1β and TNF-α cytokine levels using the ELISA test. Comparison of clinical measurements and cytokine levels between the two study groups was made using the Mann-Whitney test.

RESULT

Clinical measurements and sampling were performed on 60 patients (nA = 27, nB = 33). There was no significant difference between the two groups in clinical measurements (BI (p-value=0.96) and PI (p-value=0.06)) or TNF-α (p-value=0.63) and IL-1β (p-value=0.26) cytokine levels.

CONCLUSION

Reused healing abutments that are cleaned and sterilized properly do not appear to induce further peri-implant pro-inflammatory response; therefore, they can be utilized temporarily until implant abutment insertion. This article is protected by copyright. All rights reserved.

Early soft tissue response to zirconium oxide and titanium healing abutments in vivo: a study in dogs

Background

This study aimed to investigate the clinical characteristics and early soft tissue response to zirconium oxide (Zr) and titanium (Ti) healing abutments in dogs.

Methods

Eight implants (four at each hemi-mandible) were inserted after bilateral mandibular third and fourth premolars and first molar extraction in dogs. Then, two Zr and two Ti healing abutments were connected to each unilateral mandible eight weeks later. The ligation method was used to create a peri-implant mucositis model and the 24 abutments were divided into four groups: Zr or Ti healing abutments with ligation (ZrL, TiL) or non-ligation (ZrN, TiN). The clinical indices, peri-implant crevicular fluid (PICF), and inflammatory cytokines (TNF-α and IL-1β) were measured and analyzed on days 0 and 28. The dogs were then sacrificed on day 28, soft tissues around the implants were harvested, and inflammation infiltration was tested by immunohistochemistry. Normal distribution test and two-way analysis of variance was used to analyze the data.

Results

The results showed that the clinical indices were similar for Zr and Ti healing abutments. There was significantly more PICF in the ZrL and TiL groups compared to in the ZrN and TiN groups. The TNF-α levels in PICF were significantly different between ZrL and ZrN groups on day 28. And the TNF-α levels in PICF were significantly higher in TiL group on day 28 than that on day 0. However, the number of inflammatory cells was not significantly different between the groups as measured by immunohistochemistry.

Conclusions

These data indicate that soft tissue responses to Zr healing abutments with peri-implant mucositis were comparable to those of Ti healing abutments in vivo, providing a theoretical foundation for the clinical application of Zr abutments.

Clinical and biochemical evaluation of oral irrigation in patients with peri-implant mucositis: a randomized clinical trial

OBJECTIVE

This randomized clinical trial aimed to compare the efficacy of an oral irrigator and an interdental brush in patients with peri-implant mucositis clinically and biochemically at different time points (at baseline and at the 2nd, 4th, and 12th weeks).

MATERIALS AND METHODS

Forty-five patients with at least one implant with peri-implant mucositis were included in the present study (n = 45). The patients were divided into three groups: oral irrigator + toothbrush (OI group, n = 15), interdental brush + toothbrush (IB group, n = 15), and toothbrush only (control) (C group, n = 15). The modified plaque index (mPlI), modified sulcus bleeding index (mSBI), probing pocket depth (PPD), probing attachment level (PAL), and bleeding on probing (BOP) were recorded at baseline and at the 2nd, 4th, and 12th weeks. The levels of interleukin 1 beta (IL-1β), transforming growth factor-beta (TGF-β), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) were also determined in the peri-implant crevicular fluid samples biochemically.

RESULTS

The mSBI and t-PA at the 2nd week (p = 0.003; p = 0.003); the mPlI, mSBI, BOP, t-PA, and PAI-1 at the 4th week (p < 0.05; p < 0.001; p < 0.001; p = 0.015; p = 0.011); and the mPlI, mSBI, IL-1β, t-PA, and PAI-1 at the 12th week (p < 0.05; p < 0.001; p = 0.013; p < 0.001; p = 0.002) were significantly lower in the OI group compared with those in the C group. Meanwhile, PAI-1 at the 2nd week, mSBI at the 4th week, and t-PA at the 12th week were significantly lower in the OI group compared with those in the IB group (p < 0.001; p = 0.011; p = 0.003). At the 2nd, 4th, and 12th weeks, all other parameters were not statistically different in the three groups.

CONCLUSION

The clinical indexes (such as mSBI and BOP) that play an important role in the diagnosis of peri-implant mucositis showed the lowest means (although limited) in the OI group at all evaluation time points. Moreover, when the clinical and biochemistry results were interpreted altogether, it became apparent that the OI group exhibited similar or more effective results than the IB group in resolving peri-implant mucositis. In light of the foregoing, this study concluded that the use of an oral irrigator can be as effective as an interdental brush in interdental cleaning.

CLINICAL RELEVANCE

In this study, it is suggested that the regular use of an oral irrigator along with a toothbrush could be an appropriate alternative to other oral hygiene products such as dental floss and interdental brush for the management of peri-implant mucositis by preventing the accumulation of dental plaque (NCT03844035).

Periodontal and Implant Radiology

Dental radiography can be used to detect alveolar bone levels around periodontal and peri-implant structures. Periodontal radiographic images can assess alveolar bone height, periodontal ligament, furcation involvement, and evidence of bone destruction. Peri-implant radiographic images can assess the alveolar bone height in relation to the implant structure. As an adjunct to patient care, radiography can aid in the diagnosis of non-health.

Biomarkers associated with periodontitis and peri-implantitis: a systematic review

Purpose

The pathology of peri-implantitis is still not fully understood and there have been recent challenges to the consensus on its aetiology and pathology, especially in comparison with periodontitis. The assessment of biomarkers allows a comparison of the pathology of these diseases. The aim of this systematic review was to answer the research question: “Is there a difference in the biomarkers associated with peri-implantitis compared with periodontitis in adult humans?”

Methods

Electronic databases were searched and screened, and a manual search was also undertaken. The inclusion criteria were adults with peri-implantitis who had been compared to adults with periodontitis with the outcome of biomarkers assessed via biopsies or crevicular fluid samples in primary or secondary care settings, as recorded in case-control, case series and retrospective, prospective and cross-sectional observational studies. Two reviewers independently screened titles and abstracts and assessed full text articles for eligibility and inclusion. Both reviewers independently extracted data and assessed risk of bias. Differences in biomarker levels were the primary outcome and a narrative review was undertaken due to the heterogeneity of studies.

Results

In total, 2,374 articles were identified in the search, of which 111 full-text articles were assessed for eligibility and 13 were included in the qualitative synthesis. Five of the 13 included studies were deemed to be at high risk of bias, with the others having moderate risk. All studies were cross-sectional and performed at university hospitals. Nine of the 13 included studies found significant differences in the levels of biomarkers or their ratios between peri-implantitis and periodontitis. Four of the studies found no significant differences.

Conclusions

Within the limitations of the included studies, it appears that there may be a difference in biomarker levels and ratios between peri-implantitis and periodontitis, suggesting that these disease processes are somewhat distinct.

Microbial and host-derived biomarker changes during ligature-induced and spontaneous peri-implantitis in the Beagle dog

OBJECTIVE

To evaluate microbial and host-derived biomarker changes during experimental peri-implantitis in the Beagle dog.

BACKGROUND

Limited data exist on the microbial and biomarker changes during progressive bone loss as result of experimental peri-implantitis.

METHODS

In total, 36 implants (n_dogs  = 6) were assessed over 3 episodes of ligature-induced peri-implantitis followed by a period of spontaneous progression. Implants with hybrid (H) and completely rough (R) surface designs were used. Clinical and radiographic parameters were recorded at 4 timepoints. Peri-implant sulcus fluid was collected from the buccal and lingual aspects of the implants. The presence of 7 bacterial species and 2 host-derived biomarkers was assessed during the study period.

RESULTS

Total bacterial counts were significantly correlated with marginal bone loss (MBL) (r = .21; P = .009). Further, Phorphyromonas gulae (Pg) and Tannerella forsythia (Tf) were commonly correlated with MBL, suppuration (SUP) and the sulcular bleeding index scores (mSBI) (P < .05). Other bacteria were further correlated with SUP, mSBI, and MBL. While the analyzed bacteria dropped, Prevotella intermedia (Pi) further increased during the spontaneous progressive phase (P < .05). Total bacterial load did not differ significantly between H and R implants. Host-derived IL-10 was undetected along the study period. IL-1β positively correlated with probing pocket depth (r = .18; P = .03). During spontaneous progression, H implants displayed statistically significant lower levels of IL-1β (P = .003).

CONCLUSION

Experimental peri-implantitis is associated with an increase in bacterial counts. While Pg and Tf are associated with ligature-induced disease progression, Pi augmented its load during the spontaneous progressive phase. IL-1β is associated with pocket probing depth and influenced by implant surface characteristics during the spontaneous progression phase.

Peri-Implantitis Diagnosis and Prognosis Using Biomarkers in Peri-Implant Crevicular Fluid: A Narrative Review

Dental implant diseases, peri-implantitis (PI) and peri-implant mucositis (PIM), have shown wide prevalence in recent studies. Despite the prevalence, diagnosing peri-implant disease (PID) remains challenging as common diagnostic methods of periodontal probing and radiographs may be inaccurate. These methods only document pre-existing destruction rather than current disease activity. Furthermore, there is no current model to predict the progression of PID. Though a predictive model is lacking, biomarkers may offer some potential. Biomarkers are commonly used in medicine to objectively determine disease state, or responses to a therapeutic intervention. Gingival crevicular fluid (GCF) biomarkers have moderate diagnostic validity in periodontitis. Biomarkers in peri-implant crevicular fluid (PICF) also show promising results in regard to their diagnostic and prognostic value. The aim of this review is to summarize the current knowledge of PICF biomarkers in the diagnosis of PID and evaluate their validity to predict disease progression. This review found that PICF studies utilize different methods of sampling and interpretation with varying validity (sensitivity and specificity). A number of promising diagnostic techniques were identified. Commercially available chair-side tests for MMP-8 to diagnose periodontal disease and PID activity are now available. Future directions include proteomics and metabolomics for accurate, site-specific diagnosis and prediction of PID progression. Although more research is needed, this review concludes that the assessment of proinflammatory cytokines (IL-1β, TNFα, MMP-8) in the PICF may be of value to diagnose PI and PIM but current research remains insufficient to indicate whether biomarkers predict peri-implant disease progression.

Peri-implant mucositis

OBJECTIVES

This narrative review was prepared for the 2017 World Workshop of the American Academy of Periodontology and European Federation of Periodontology to address key questions related to the clinical condition of peri-implant mucositis, including: 1) the definition of peri-implant mucositis, 2) conversion of peri-implant health to the biofilm-induced peri-implant mucositis lesion, 3) reversibility of peri-implant mucositis, 4) the long-standing peri-implant mucositis lesion, 5) similarities and differences between peri-implant mucositis at implants and gingivitis at teeth, and 6) risk indicators/factors for peri-implant mucositis.

METHODS

A literature search of MEDLINE (PubMed) and The Cochrane Library up to and including July 31, 2016, was carried out using the search strategy (peri-implant[All Fields] AND ("mucositis"[MeSH Terms] OR "mucositis"[All Fields])) OR (periimplant[All Fields] AND mucosits[All Fields]). Prospective, retrospective, and cross-sectional studies and review papers that focused on risk factors/indicators for peri-implant mucositis as well as experimental peri-implant mucositis studies in animals and humans were included.

FINDINGS

Peri-implant mucositis is an inflammatory lesion of the soft tissues surrounding an endosseous implant in the absence of loss of supporting bone or continuing marginal bone loss. A cause-and-effect relationship between experimental accumulation of bacterial biofilms around titanium dental implants and the development of an inflammatory response has been demonstrated. The experimental peri-implant mucositis lesion is characterized by an inflammatory cell infiltrate present within the connective tissue lateral to the barrier epithelium. In long-standing peri-implant mucositis, the inflammatory cell infiltrate is larger in size than in the early (3-week) experimental peri-implant mucositis lesion. Biofilm-induced peri-implant mucositis is reversible at the host biomarker level once biofilm control is reinstituted. Reversal of the clinical signs of inflammation may take longer than 3 weeks. Factors identified as risk indicators for peri-implant mucositis include biofilm accumulation, smoking, and radiation. Further evidence is required for potential risk factors, including diabetes, lack of keratinized mucosa, and presence of excess luting cement.

CONCLUSIONS

Peri-implant mucositis is caused by biofilm accumulation which disrupts the host-microbe homeostasis at the implant-mucosa interface, resulting in an inflammatory lesion. Peri-implant mucositis is a reversible condition at the host biomarker level. Therefore, the clinical implication is that optimal biofilm removal is a prerequisite for the prevention and management of peri-implant mucositis. An understanding of peri-implant mucositis is important because it is considered a precursor for peri-implantitis.

Peri-implant mucositis

OBJECTIVES

This narrative review was prepared for the 2017 World Workshop of the American Academy of Periodontology and European Federation of Periodontology to address key questions related to the clinical condition of peri-implant mucositis, including: 1) the definition of peri-implant mucositis, 2) conversion of peri-implant health to the biofilm-induced peri-implant mucositis lesion, 3) reversibility of peri-implant mucositis, 4) the long-standing peri-implant mucositis lesion, 5) similarities and differences between peri-implant mucositis at implants and gingivitis at teeth, and 6) risk indicators/factors for peri-implant mucositis.

METHODS

A literature search of MEDLINE (PubMed) and The Cochrane Library up to and including July 31, 2016, was carried out using the search strategy (peri-implant[All Fields] AND ("mucositis"[MeSH Terms] OR "mucositis"[All Fields])) OR (periimplant[All Fields] AND mucosits[All Fields]). Prospective, retrospective, and cross-sectional studies and review papers that focused on risk factors/indicators for peri-implant mucositis as well as experimental peri-implant mucositis studies in animals and humans were included.

FINDINGS

Peri-implant mucositis is an inflammatory lesion of the soft tissues surrounding an endosseous implant in the absence of loss of supporting bone or continuing marginal bone loss. A cause-and-effect relationship between experimental accumulation of bacterial biofilms around titanium dental implants and the development of an inflammatory response has been demonstrated. The experimental peri-implant mucositis lesion is characterized by an inflammatory cell infiltrate present within the connective tissue lateral to the barrier epithelium. In long-standing peri-implant mucositis, the inflammatory cell infiltrate is larger in size than in the early (3-week) experimental peri-implant mucositis lesion. Biofilm-induced peri-implant mucositis is reversible at the host biomarker level once biofilm control is reinstituted. Reversal of the clinical signs of inflammation may take longer than 3 weeks. Factors identified as risk indicators for peri-implant mucositis include biofilm accumulation, smoking, and radiation. Further evidence is required for potential risk factors, including diabetes, lack of keratinized mucosa, and presence of excess luting cement.

CONCLUSIONS

Peri-implant mucositis is caused by biofilm accumulation which disrupts the host-microbe homeostasis at the implant-mucosa interface, resulting in an inflammatory lesion. Peri-implant mucositis is a reversible condition at the host biomarker level. Therefore, the clinical implication is that optimal biofilm removal is a prerequisite for the prevention and management of peri-implant mucositis. An understanding of peri-implant mucositis is important because it is considered a precursor for peri-implantitis.

Impact of photodynamic therapy versus ultrasonic scaler on gingival health during treatment with orthodontic fixed appliances

OBJECTIVES

Poor oral hygiene during treatment with fixed appliances results in plaque accumulation. The presence of bacteria in the gingival crevice triggers an inflammatory reaction in the gingival tissues. The aim of this study was to compare the impact of two preventive treatments, photodynamic therapy (PDT), and ultrasonic scaler (US), on gingival health in patients under fixed orthodontic treatment.

METHODS

Twenty orthodontic patients were randomly allocated to two groups: PDT or US. Each group received seven sessions [days 0, 15, 30, 45, 90 (3-months follow-up), 180 (6-months follow-up), 270 (9-months follow-up)] of experimental interventions, and clinical parameters [Plaque index(PI); gingival index(GI); probing depth(PD)], periodontopathogens [Agreggatibacter actinomycetemcomitans; Porphyromonas gingivalis; Prevotella intermedia; Micromonas micros; Fusobacterium nucleatum; Tannerella forsythia; Campylobacter rectus; Eikenella corrodens; Capnocytopaga sp.] and protein markers [IL-1β;IL-1ra;IL-6;IL-10;TNF-α;FGF-2/FGF basic] were monitored at baseline and at 3, 6, and 9 months. ANOVA, Student's t-test with Bonferroni correction and ANOVA with multiple rank test were used to identify differences between groups (P < 0.05).

RESULTS

Clinical assessments [PI, GI, and PD] yielded no differences (P > 0.05) between groups, which showed a major decrease at the start of the trial. Reductions in total colony forming units (log CFU reduction) were observed with both treatments, although to a greater extent in the PDT group, but with no differences between groups (P > 0.05). Similar reductions in log CFU counts of P. gingivalis, P. intermedia, and F. nucleatum were observed in both groups (P > 0.05). The two groups also showed similar trends for inflammatory mediators with decreased levels of IL-1β, IL-10, and TNF-α, whereas IL-6 and IL-1ra levels remained stable and those of FGF-2 were increased after both interventions, with no differences (P > 0.05) between groups.

CONCLUSION

Both PDT and US methods proved similar effectiveness for the treatment of gingival inflammation induced by fixed orthodontic appliances. Lasers Surg. Med. 51:256-267, 2019. © 2018 Wiley Periodicals, Inc.

Roles of a new drug-delivery healing abutment in the prevention and treatment of peri-implant infections: a preliminary study

In this study we modified the common healing abutment into a specifically designed drug-delivery abutment (DDA), which is a hollow columnar system with drug-distribution holes in peripheral wall. The objective of this study was to investigate the possibility of the prevention and treatment of peri-implant diseases with this drug-delivery system. Minocycline hydrochloride was added to DDAs with different hole diameters, and then subjected to bacteria-inhibition tests in vitro with three oral bacterial strains, namely, Streptococcus mutans, Streptococcus sanguinis, and Porphyromonas gingivalis. The implants were placed into the mandible of beagle dogs. DDAs with or without minocycline and normal healing abutments were installed. One week after surgery, the plaques on all the abutments were analyzed by plaque stain. Following this, both abutments and adjacent teeth received oral hygiene to maintain a healing environment. Eleven weeks later, the ligature-induced experimental peri-implantitis model was set up for eight weeks. Periapical radiographs and clinical measurements were performed during the process. We found that inhibition zones were observed surrounding all the tested drug-delivery abutments in all three bacterial strains. One week after implant installation, oral plaque formed on the DDAs with minocycline was significantly less than that on normal abutments and DDAs without drugs. DDA with the minocycline group showed a relatively slower rate of deterioration of the mucosal inflammation and probing depth in the experimental peri-implant lesions. We suggest that this drug-delivery abutment could effectively deliver medications into peri-implant tissues to minimize plaque formation and relieve peri-implant inflammation in the experimental peri-implantitis model.

Current understanding of genetic polymorphisms as biomarkers for risk of biological complications in implantology

Background

In the last decade, multiple studies have been published that analyze the relationship between the risk of experiencing biological complications with implants and the presence of certain types of genetic polymorphisms. In the present report, we analyze the controversies that have arisen from this important area of investigation and synthesize the most prominent aspects of knowledge related to this possible etiopathogenic relationship.

Material and Methods

For this review, the biomedical databases PubMed-Medline, SciELO, and DOAJ were used. Different search strategies were employed, from which 298 articles initially emerged. After refinement of the search, 55 articles published between 2002 and 2018 were finally selected based on relevance.

Results

In certain population groups, there is evidence to support that about a dozen polymorphisms could in some way be related to biological complications in implantology. Indeed, the results may vary according to the ethnic origin of the population studied. Most of the published investigations are initial studies reporting small sample sizes and utilizing different study group homogenization methods. We are still at a preliminary stage of our understanding and development with regard to these types of biomarkers. The interesting results identified indicate that new investigations will be necessary to eliminate the biases observed in some studies and to homogenize the research groups. In order to clarify the controversies surrounding the current knowledge in this field, we believe that it will be necessary to employ larger study groups and search for possible synergistic effects between different polymorphisms.

Key words:Polymorphism, genetic markers, peri-implantitis, biological complication, dental implant.

Development and in vitro evaluation of chitosan based system for local delivery of atorvastatin for treatment of periodontitis

In recent years, statin group drugs have been widely investigated in treatment of periodontal diseases due to their anti-inflammatory effect. The efficacy of statins can be enhanced by local administration into the periodontal pocket by appropriate delivery systems. The aim of our study was to develop a bioadhesive delivery system for local delivery of atorvastatin in treatment of periodontal disease. For this purpose, gel formulations were prepared using different types of chitosan (base and water soluble) and viscosity, bioadhesivity and syringeability of the gels as well as in vitro drug release properties were investigated vitro. Furthermore, anti-inflammatory effect of the formulations was studied in vitro using tumor necrosis factor (TNF)-alfa induced human gingival fibroblast (hGF) cells. Release of proinflammatory (IL-1β, IL-6, IL-8) and anti-inflammatory (TGF-β1, TGF-β2, TGF-β3, IL-10) cytokines were measured after incubating the hGF cells with the formulations. The viscosity of the formulations was found to be suitable for a local application into periodontal pocket. In presence of drug, bioadhesive property of the formulations was found to increase, and bioadhesion force was within the range, which would retain the delivery system at the application site, subsequently maintain drug levels at desired amount for longer period of time. The release of atorvastatin from the gels was found to be slower than that of the solution. The cytokine levels were found to decrease following application of the formulations, and anti-inflammatory effect was observed to enhance in presence of chitosan. No significant differences were found between base and water-soluble chitosan.

A review of biomarkers in peri-miniscrew implant crevicular fluid (PMICF)

Background

The temporary anchorage devices (TADs) which include miniscrew implants (MSIs) have evolved as useful armamentarium in the management of severe malocclusions and assist in complex tooth movements. Although a multitude of factors is responsible for the primary and secondary stability of miniscrew implants, contemporary research highlights the importance of biological interface of MSI with bone and soft tissue in augmenting the success of implants.

The inflammation and remodeling associated with MSI insertion or loading are reflected through biomarkers in peri-miniscrew implant crevicular fluid (PMICF) which is analogous to the gingival crevicular fluid. Analysis of biomarkers in PMICF provides indicators of inflammation at the implant site, osteoclast differentiation and activation, bone resorption activity and bone turnover. The PMICF for assessment of these biomarkers can be collected non-invasively via paper strips, periopaper or micro capillary pipettes and analysed by enzyme-linked immunosorbent assay (ELISA) or immunoassays. The markers and mediators of inflammation have been previously studied in relation to orthodontic tooth movement include interleukins (IL-1β, IL-2, IL-6 and IL-8), growth factors and other proteins like tumour necrosis factor (TNF-α), receptor activator of nuclear factor kappa-B ligand (RANKL), chondroitin sulphate (CS) and osteoprotegerin (OPG).

Studies have indicated that successful and failed MSIs have different concentrations of biomarkers in PMICF. However, there is a lack of comprehensive information on this aspect of MSIs. Therefore, a detailed review was conducted on the subject.

Results

A literature search revealed six relevant studies: two on IL-1β; one on IL-2, IL-6 and IL-8; one on TNF-α; one on CS; and one on RANKL/OPG ratio. One study showed an increase in IL-1β levels upon MSI loading, peak in 24 hours (h), followed by a decrease in 21 days to reach baseline in 300 days. A 6.87% decrease in IL-2 levels was seen before loading and a 5.97% increase post-loading. IL-8 showed a 6.31% increase after loading and IL-6 increased by 3.08% before MSI loading and 15.06% after loading. RANKL/OPG ratio increased in loaded compared to unloaded MSIs.

Conclusions

Cytokines (mainly ILs and TNF-α) and RANKL/OPG ratio showed alteration in PMICF levels upon loading of MSIs as direct or indirect anchorage.

Associations of alveolar bone loss and interleukin-1β levels in one- and two-stage surgical procedures: a randomized prospective trial

OBJECTIVE

Dental implants have been widely and successfully used in recent years as an alternative treatment for removable and fixed dental prostheses. The aim of this randomized prospective study was to determine the alveolar bone loss rate (ABLR) and IL-1β levels in one- and two-stage surgical procedures.

MATERIALS AND METHODS

This study included 40 patients with a single missing tooth in the posterior mandible; dental implants were inserted using a one-stage surgical procedure (Group I) or a two-stage surgical procedure (Group II). All clinical periodontal parameters were recorded; peri-implant crevicular fluid (PICF) samples were collected before loading (T0) and during the third (T1) and sixth (T2) months after loading. ABLR values were evaluated at T0 and T2 by using dental tomography. PICF was analysed after T2 samples were collected. The study was registered through clinicaltrials.gov; identifier NCT03045458.

RESULTS

This study found that, the probing pocket depth was found to be significantly higher in Group I than Group II at both T1 and T2 (p < .05). There was no significant difference in other clinical parameters between the groups (p > .05). There was a significant difference between Group I ABLR values at T0 and T2 (p < .05). The PICF IL-1β levels were not significantly different between groups (p > .05).

CONCLUSIONS

Within the limitations of the short observational period and small sample size of this study, two-stage implant placement shows comparable clinical outcomes to implants placed using a one-stage placement protocol.

Effects of Four Different Crown Materials on the Peri-Implant Clinical Parameters and Composition of Peri-Implant Crevicular Fluid

This study aimed to identify the preferred crown material by measuring the peri-implant clinical parameters and the concentrations of receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), and calcium in peri-implant crevicular fluid (PICF) with 4 different crown materials. A total of 196 patients with a single missing posterior tooth received crown restoration with cobalt-chromium (Co-Cr) porcelain-fused-to-metal (PFM; n = 50), aurum platinum (Au-Pt) PFM (n = 48), titanium (Ti) PFM (n = 52), or zirconia (Zi) all-ceramic crown (n = 46). Fifty-one natural counterpart teeth served as controls. Before and 12 months after restoration, the PICF was collected, and the concentrations of RANKL, OPG, and calcium were quantified. The peri-implant clinical parameters (plaque index, bleeding on probing, and probing depth [PD]) and gingival crevicular fluid (GCF) volumes were assessed. Twelve months after restoration, the PD and GCF volumes for the 4 experimental groups were significantly greater than those for the control group and before restoration. The Co-Cr group showed the greatest PD, GCF volume, RANKL/OPG, RANKL, and calcium ion concentration, followed by the Au-Pt group. The Ti group had the highest OPG concentration, followed by the Zi group. The RANKL and calcium ion concentrations of the Ti and Zi groups were the smallest. The Ti group had the smallest RANKL/OPG ratio, followed by the Zi group. Different crown materials differentially affected the PD, volume, RANKL/OPG ratio, OPG, RANKL, and calcium concentration. Among the 4 tested crown materials, Zi and Ti are preferred. However, some limitations of the present study should be considered.

Pro-inflammatory cytokines at zirconia implants and teeth. A cross-sectional assessment

OBJECTIVES

The aim of this study was to compare the expression of host-derived markers in peri-implant/gingival crevicular fluid (PCF/GCF) and clinical conditions at ceramic implants and contralateral natural teeth. As a secondary objective, we compared zirconia implants with titanium implants.

METHODS

One zirconia implant (ZERAMEX® Implant System) and one contralateral natural tooth were examined in 36 systemically healthy subjects (21 males, 15 females, mean age 58). The levels of Il-1β, Il-1RA, Il-6, Il-8, Il-17, b-FGF, G-CSF, GM-CSF, IFNɣ, MIP-1β, TNF-α, and VEGF were assessed in PCF/GCF using the Bio-Plex 200 Suspension Array System. The plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing (BOP) were assessed at six sites around each implant or tooth. Titanium implants were also assessed when present (n = 9).

RESULTS

The zirconia implants were examined after a loading period of at least 1.2 years (average 2.2 years). The mean PI was significantly lower at zirconia implants compared to teeth (p = 0.003), while the mean GI, PD, and BOP were significantly higher (p < 0.001). A correlation was found in the expression of Il-1RA, Il-8, G-CSF, MIP-1β, and TNF-α at zirconia implants and teeth. The levels of IL-1β and TNF-α were significantly higher at zirconia implants than at teeth. No significant differences were found between zirconia and titanium implants. A correlation was found between the levels of IL-1RA, IL-8, GM-CSF, and MIP-1β at zirconia and titanium implants.

CONCLUSIONS

The correlation in the expression of five biomarkers at zirconia implants and teeth, and of four biomarkers at zirconia and titanium implants, is compatible with the existence of a patient-specific inflammatory response pattern. Higher mean GI, PD, and BOP around implants suggests that the peri-implant mucosa may be mechanically more fragile than the gingiva.

CLINICAL RELEVANCE

Similar expression of selected biomarkers at zirconia implants and teeth and at zirconia and titanium implants reflects existence of patient-specific inflammatory response patterns.

Clinical, Immune, and Microbiome Traits of Gingivitis and Peri-implant Mucositis

Tissues surrounding dental implants and teeth develop clinical inflammation in response to microbial stimuli. However, the literature suggests that differences exist in the microbial insult and inflammatory responses leading to gingivitis and peri-implant mucositis. In this pilot study, the authors use for the first time a systems biology approach to comprehensively evaluate clinical parameters, selected inflammatory markers, and the microbiome of subject-matched tooth and implant sites during native inflammation and in response to experimental plaque accumulation. Fifteen subjects with 2 posterior implants and corresponding contralateral teeth were examined at enrollment; at day 0, after reinstitution of gingival/mucosal health; at days 7, 14, and 21, during stent-mediated oral hygiene (OH) abstention; and at day 42, after resumption of OH. The subgingival microbiome was evaluated via 16S rRNA gene sequencing and 8 selected inflammatory markers measured in crevicular fluid. Comparison of teeth and implants via general linear models based on orthogonal polynomials showed similar responses in clinical parameters, inflammatory mediators, and proportions of individual microbial taxa during OH abstention. Implants, however, accumulated less plaque and underwent more heterogeneous shifts in microbiome structure. A multilevel, within-group, sparse partial least squares analysis of covariation of microbial, inflammatory, and clinical parameters throughout all study visits found inflammation around teeth and implants positively correlated with IL-1 alpha and IL-1 beta and with the proportions of Selenomonas, Prevotella, and 5 species-level phylotypes. Gingivitis, however, showed a stronger positive correlation with lactoferrin and IL-1ra and a stronger negative correlation with Rothia. Peri-implant mucositis, on the contrary, correlated positively with certain microbial taxa not associated with gingivitis by a previous study or the current one. In summary, differences existed between implants and tooth sites in microbiome evolution during OH abstention and in the correlation of specific inflammatory mediators and microbial taxa with clinical inflammation. Common biological features, however, were also identified for gingivitis and mucositis.

Peri-implant crevicular fluid biomarkers as discriminants of peri-implant health and disease

AIM

The objective of this cross-sectional study was to examine the potential of peri-implant crevicular fluid (PICF) analytes to discriminate between peri-implant health and disease using a multi-biomarker approach.

METHODS

We collected PICF samples from the mesio-buccal site of every implant (n = 145) from 52 subjects with peri-implantitis and measured the levels of 20 biomarkers using Luminex. We grouped implants and subjects based on the clinical characteristic of the sampled sites and implants into: healthy sites from healthy implants (HH), diseased sites from diseased implants (DD) and healthy sites from diseased implants (HD). The significance of the differences between the HH and DD groups was determined using general linear models controlling for false discovery rate. We used logistic regression to determine the best multi-biomarker models that could distinguish HH from DD subjects and HH from HD subjects.

RESULTS

There were statistically significant differences between HH and DD groups for 12/20 biomarkers. Logistic regression resulted in a 6-biomarker model (Flt-3L, GM-CSF, IL-10, sCD40L, IL-17 and TNFα) that discriminated HH from DD subjects (AUC = 0.93) and a 3-biomarker model (IL-17, IL-1ra and vascular endothelial growth factor) that distinguished HH from DD subjects (AUC = 0.90).

CONCLUSION

PICF biomarkers might help discriminate peri-implant health from disease.

Peri-Implant Crevicular Fluid Analysis, Enzymes and Biomarkers: a Systemetic Review

OBJECTIVES

To review the current understanding of the biomarkers and enzymes associated with different forms peri-implant diseases and how their level changes influence the pathogenesis of the inflammatory diseases around dental implants.

MATERIAL AND METHODS

An electronic search in two different databases was performed including MEDLINE (PubMed) and EMBASE between 1996 to 2016. Human studies analyse peri-implant crevicular fluid (PICF) biomarker and enzyme levels of implants having peri-implant mucositis and peri-implantitis published in English language, were evaluated. A systematic review was performed to assess which biomarkers and enzymes in PICF were used to identify the inflammatory conditions around dental implants.

RESULTS

Fifty-one articles were identified of which 41 were further evaluated and included in the analysis. Due to significant heterogeneity between included studies, a meta-analysis could not be performed. Instead, a systematic descriptive review was performed.

CONCLUSIONS

Biomarkers and enzymes in peri-implant crevicular fluid have shown promising results in differentiating from peri-implant disease condition to health. However, due to inconsistent results and acquiring much evidence from cross-sectional studies, additional evidence supported by randomized-controlled trials is needed to validate the links reported.

Protein biomarkers of external root resorption: a new protein extraction protocol. Are we going in the right direction?

OBJECTIVE

The aim of this study is to determine a protocol of gingival crevicular fluid protein extraction used for the first dimension of 2-DE gels. It also aims at conducting a review on the current candidates for protein markers of this pathology, all of which may be used to prevent the disease.

METHODS

Gingival crevicular fluid was collected from two groups of 60 patients each, with and without external root resorption. Samples were extracted by means of various methods of protein extraction. SDS-PAGE gels were used to assess the quality of the method which was subsequently tested during isoelectric focusing of 2-DE gels taken from samples of patients with and without the disease.

RESULTS

Milli-Q ultrapure ice cold water, without precipitation for gingival crevicular fluid protein extraction, proved the method with greatest sharpness to detect protein bands. Additionally, it allowed two-dimensional electrophoresis to be performed.

CONCLUSION

The new protein extraction protocol does not interfere in isoeletric focusing of 2-DE gels. Furthermore, it provides the greatest sharpness in detecting protein bands of SDS-PAGE gels. This will allow mapping and searching of new external root resorption markers, particularly due to the difficulty in carrying out molecular tests with the current candidates for protein markers.

Protein biomarkers and microbial profiles in peri-implantitis

OBJECTIVES

The aim of the present investigation was to determine the profile of peri-implant crevicular fluid (PICF) biomarkers combined with microbial profiles from implants with healthy peri-implant tissues and peri-implantitis to assess real-time disease activity.

MATERIAL AND METHODS

Sixty-eight patients were included in this cross-sectional study. They were divided into two groups: 34 patients with at least one healthy implant (control) and 34 with at least one peri-implantitis affected implant (test). Total DNA content and qPCR analysis for periodontal bacteria obtained from subgingival plaque samples (Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) and a PICF analysis for IL-1β, VEGF, MMP-8, TIMP-2, and OPG were performed. The individual and combined diagnostic ability of each biomarker for peri-implantitis and target bacterial species were analyzed.

RESULTS

The mean concentration of IL-1β (44.6 vs. 135.8 pg/ml; P < 0.001), TIMP-2 (5488.3 vs. 9771.8 pg/ml; P = 0.001), VEGF (59.1 vs. 129.0 pg/ml; P = 0.012), and OPG (66.5 vs. 111.7 pg/ml; P = 0.050) was increased in the peri-implantitis patients. The mean expression of MMP-8 (6029.2 vs. 5943.1 pg/ml; P = 0.454) and did not reveal a meaningful difference among groups. Total bacterial DNA of selected microorganisms was associated with a threefold or greater increase in peri-implantitis although no statistical significant difference. The ability to diagnose diseased sites was enhanced by T. denticola combined with IL-1β, VEGF, and TIMP-2 PICF levels.

CONCLUSION

The present data suggest that the increased levels of the selected PICF-derived biomarkers of periodontal tissue inflammation, matrix degradation/regulation, and alveolar bone turnover/resorption combined with site-specific microbial profiles may be associated with peri-implantitis and could have potential as predictors of peri-implant diseases.

Efficacy of patient-administered mechanical and/or chemical plaque control protocols in the management of peri-implant mucositis. A systematic review

AIM

To systematically assess the efficacy of patient-administered mechanical and/or chemical plaque control protocols in the management of peri-implant mucositis (PM).

MATERIAL AND METHODS

Randomized (RCTs) and Controlled Clinical Trials (CCTs) were identified through an electronic search of three databases complemented by manual search. Identification, screening, eligibility and inclusion of studies was performed independently by two reviewers. Studies without professional intervention or with only mechanical debridement professionally administered were included. Quality assessment was performed by means of the Cochrane Collaboration's tool for assessing risk of bias.

RESULTS

Eleven RCTs with a follow-up from 3 to 24 months were included. Definition of PM was lacking or heterogeneously reported. Complete resolution of PM was not achieved in any study. One study reported 38% of patients with complete resolution of PM. Surrogate end-point outcomes of PM therapy were often reported. The choice of control interventions showed great variability. The efficacy of powered toothbrushes, a triclosan-containing toothpaste and adjunctive antiseptics remains to be established. High quality of methods and reporting was found in four studies.

CONCLUSIONS

Professionally- and patient-administered mechanical plaque control alone should be considered the standard of care in the management of PM. Therapy of PM is a prerequisite for the prevention of peri-implantitis.

Can peri-implant crevicular fluid assist in the diagnosis of peri-implantitis? A systematic review and meta-analysis

BACKGROUND

A broader understanding of the immune inflammatory profile of peri-implant diseases could be helpful in the development of host-targeted preventive and therapeutic strategies. The aim of this study is to answer two clinical questions: 1) whether patients with peri-implantitis (PP) present higher prevalence of any specific inflammatory cytokine in peri-implant crevicular fluid (PICF) compared with healthy patients; and 2) whether local inflammation measured in PICF can be used as a predictor for incipient PP.

METHODS

A systematic review of the literature on the most common cytokines released in PICF in healthy and PP-affected sites was conducted from 1996 up to and including October 2013 using predefined search strategies. Cross-sectional and prospective longitudinal studies were considered. Meta-analyses were done separately for healthy, mucositis (MU), and PP outcomes.

RESULTS

Interleukin (IL)-1β was the most studied cytokine (n = 12), followed by tumor necrosis factor (TNF)-α (n = 10). Other cytokines were also linked to PP, such as IL-4, IL-6, IL-8, IL-10, IL-12, and IL-17. Statistical differences were revealed when IL-1β release was compared between healthy implant sites and PP (P = 0.001) or MU sites (P = 0.002), respectively; when PP and MU were compared, no statistical differences could be detected (P = 0.80). For TNF-α release, significant differences were found between healthy and PP implants (P = 0.02).

CONCLUSIONS

PICF containing inflammatory mediators, such as IL-1β and TNF-α, can be used as additional criteria for a more robust diagnosis of peri-implant infection. Additionally, once the inflammatory process is installed, no differences were found between peri-implant MU and PP.

Saliva versus peri-implant inflammation: quantification of IL-1β in partially and totally edentulous patients

The aim of this study was to investigate the potential use of salivary IL1β in early-stage diagnostics of peri-implant inflammation in partially and totally edentulous patients rehabilitated with dental implants. Patients were classified according to peri-implant probing depth and bleeding upon probing in groups of healthy individuals or in groups of individuals with peri-implant inflammation. Data on plaque index, clinical attachment loss, suppuration, and mobility were also assessed. Saliva was collected without stimulation, and the levels of IL-1β were determined by ELISA. Healthy groups demonstrated significantly lower levels of IL-1β compared with the inflammation groups. No difference in IL-1β levels was observed between partially edentulous or totally edentulous patients. Salivary IL-1β may be useful for the diagnosis and monitoring of early peri-implant inflammation, particularly in edentulous patients.

Single-blind randomized clinical trial to evaluate clinical and radiological outcomes after one year of immediate versus delayed implant placement supporting full-arch prostheses

Purpose: To evaluate and compare peri-implant health, marginal bone loss and success of immediate and delayed implant placement for rehabilitation with full-arch fixed prostheses. Material and Methods: The present study was a prospective, randomized, single-blind, clinical preliminary trial. Patients were randomized into two treatment groups. In Group A implants were placed immediately post-extraction and in Group B six months after extraction. The following control time-points were established: one week, six months and twelve months after loading. Measurements were taken of peri-implant crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis. Implant success rates were evaluated for the two groups. The study sample included fifteen patients (nine women and six men) with a mean average age of 63.7 years. One hundred and forty-four implants were placed: 76 placed in healed sites and 68 placed immediately. Results: At the moment of prosthetic loading, keratinized mucosa width and probing depth were higher in immediate implants than delayed implants, with statistically significant differences. However, after six and twelve months, differences between groups had disappeared. Bone loss was 0.54 ± 0.39 mm for immediate implants and 0.66 ± 0.25 mm for delayed implants (p=0.201). No implants failed in either group. Conclusions: The present study with a short follow-up and a small sample yielded no statistically significant differences in implant success and peri-implant marginal bone loss between immediate and delayed implants with fixed full-arch prostheses. Peri-implant health showed no statistically significant differences for any of the studied parameters (crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis) at the twelve-month follow-up.

Key words:Immediate implants, delayed implants, peri-implant health, success rate.

Influence of occlusal loading on peri-implant clinical parameters. A pilot study

Objectives: To investigate the relation between occlusal loading and peri-implant clinical parameters (probing depth, bleeding on probing, gingival retraction, width of keratinized mucosa, and crevicular fluid volume) in patients with implant-supported complete fixed prostheses in both arches. Material and Methods: This clinical study took place at the University of Valencia (Spain) dental clinic. It included patients attending the clinic for regular check-ups during at least 12 months after rehabilitation of both arches with implant-supported complete fixed ceramo-metallic prostheses. One study implant and one control implant were established for each patient using the T-Scan®III computerized system (Tesco, South Boston, USA). The maxillary implant closest to the point of maximum occlusal loading was taken as the study implant and the farthest (with least loading) as the control. Occlusal forces were registered with the T-Scan® III and then occlusal adjustment was performed to distribute occlusal forces correctly. Peri-implant clinical parameters were analyzed in both implants before and two and twelve months after occlusal adjustment. Results: Before occlusal adjustment, study group implants presented a higher mean volume of crevicular fluid (51.3±7.4 UP) than the control group (25.8±5.5 UP), with statistically significant difference. Two months after occlusal adjustment, there were no significant differences between groups (24.6±3.8 UP and 26±4.5 UP respectively) (p=0.977). After twelve months, no significant differences were found between groups (24.4±11.1 UP and 22.5±8.9 UP respectively) (p=0.323). For the other clinical parameters, no significant differences were identified between study and control implants at any of the study times (p>0.05). Conclusions: Study group implants receiving higher occlusal loading presented significantly higher volumes of crevicular fluid than control implants. Crevicular fluid volumes were similar in both groups two and twelve months after occlusal adjustment.

Key words:Occlusal loading, crevicular fluid, peri-implant clinical parameters, T-Scan®.

Comparison of pro-inflammatory cytokines and bone metabolism mediators around titanium and zirconia dental implant abutments following a minimum of 6 months of clinical function

OBJECTIVES

Dental implant abutments are fundamental prosthetic components within dentistry that require optimal biocompatibility. The primary aim of this cross-sectional study was to preliminarily assess differences in the pro-inflammatory cytokine and bone metabolism mediator protein expression in the peri-implant crevicular fluid (PICF) adjacent to transmucosal abutments.

MATERIAL AND METHODS

Abutments were fabricated from either titanium or zirconia in patients previously receiving single-tooth implant therapy. All subjects sampled in this study had an identical implant system and implant-abutment connection. Participants (n = 46) had an average time of clinical function for 22 months (6.2-72.8 months, ±SD 17 months) and received a clinical and radiographic examination of the implant site at the time of PICF sampling using a paper strip-based sampling technique. Cytokine, chemokine, and bone metabolism mediator quantities (picograms/30 s) were determined using a commercial 22-multiplexed fluorescent bead-based immunoassay instrument. A total of 19 pro-inflammatory cytokines and seven bone metabolism mediators were evaluated.

RESULTS

Multivariable analyses provided no evidence of a group (titanium or zirconia), gender, or age effect with regard to the expression of pro-inflammatory mediators evaluated. Significant (P = 0.022) differences were observed for the bone mediator leptin, with titanium abutments demonstrating significantly elevated levels in comparison with zirconia. Osteopontin demonstrated a significant (P = 0.0044) correlation with age of the subjects.

CONCLUSIONS

No significant differences in pro-inflammatory cytokine or bone metabolism mediator profiles were observed biochemically, with the exception of leptin, for the abutment biomaterials of titanium or zirconia The molecular PICF findings support the observed clinical biocompatibility of both titanium and zirconia abutments.

The effects of silorane composites on levels of cytokines and periodontal parameters

Aims:

The purpose of this pilot study was to determine the effects of silorane composites on gingival crevicular fluid (GCF) levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and IL-8, GCF volume and clinical periodontal parameters in patients with silorane composite restorations before and after restorative treatment.

Materials and Methods:

A total of 20 systemically healthy non-smokers, 12 female and 8 male (age range: 24-46 years), presenting with 25 instances of primary dentine caries with subgingival margins were selected for this study. Approval was obtained from the university ethics committee and treatment plans were approved by the patients. GCF samples were obtained with periopaper strips from relevant teeth for IL-6, IL-8 and TNF-α measurements. Each sample was stored at − 80°C and analyzed using the enzyme-linked immunosorbent assay (ELISA) kits. Cavities were prepared according to the common principles for adhesive restorations and restored with a silorane adhesive system (Silorane System Adhesive (3M ESPE) and silorane composite (Filtek Silorane, 3M ESPE). Cytokine levels were reassessed 2 weeks after restorative treatment. Data were analyzed using the independent t-test at a significance level of α =0.05. Associations between parameters were analyzed using Pearson correlation analysis.

Results:

A significant increase in gingival index (GI) and plaque index (PI) were observed after 15 days (P < 0.05). GCF volume, IL-6, IL-8 and TNF-α levels exhibited significant differences before and after restorative treatment (P < 0.05). There were strong positive correlations among parameters except for PI/GCF volume and GI/GCF volume.

Conclusion:

Within the limitations of this investigation, silorane composites may have some negative effects on cytokine levels, clinical parameters and GCF volume.

Comparative volumetric and clinical evaluation of peri-implant sulcular fluid and gingival crevicular fluid

Purpose

Peri-implant sulcular fluid (PISF) has a production mechanism similar to gingival crevicular fluid (GCF). However, limited research has been performed comparing their behavior in response to inflammation. Hence, the aim of the present study was to comparatively evaluate PISF and GCF volume with varying degrees of clinical inflammatory parameters.

Methods

Screening of patients was conducted. Based on the perimucosal inflammatory status, 39 loaded implant sites were selected from 24 patients, with equal numbers of sites in healthy, peri-implant mucositis, and peri-implantitis subgroups. GCF collection was done from age- and sex-matched dentate patients, selected with gingival inflammatory status corresponding to the implant sites. Assessment of the inflammatory status for dental/implant sites was performed using probing depth (PD), plaque index/modified plaque index (PI/mPI), gingival index/simplified gingival index (GI/sGI), and modified sulcular bleeding index (BI). Sample collection was done using standardized absorbent paper strips with volumetric evaluation performed via an electronic volume quantification device.

Results

Positive correlation of the PISF and GCF volume was seen with increasing PD and clinical inflammatory parameters. A higher correlation of GCF with PD (0.843) was found when compared to PISF (0.771). PISF expressed a higher covariation with increasing grades of sGI (0.885), BI (0.841), and mPI (0.734), while GCF established a moderately positive correlation with GI (0.694), BI (0.696), and PI (0.729).

Conclusions

Within the limitations of this study, except for minor fluctuations, GCF and PISF volumes demonstrated a similar nature and volumetric pattern through increasing grades of inflammation, with PISF showing better correlation with the clinical parameters.

Necessity of keratinized tissues for dental implants: a clinical, immunological, and radiographic study

BACKGROUND

Necessity of keratinized tissues (KTs) for maintaining health around dental implants (DIs) remains as a controversial issue.

PURPOSE

The aim of this study was to investigate the effects of KT width (KTW) on peri-implant tissues by evaluating peri-implant clinical and inflammatory parameters.

MATERIALS AND METHODS

Sixty DIs were included in this 6-month longitudinal study. After classifying DI based on the presence of KTs at the buccal aspect as with adequate/inadequate KTW, DIs were randomly assigned into three study groups. In the first group, while free gingival graft (FGG) was performed, DIs in maintenance (M) group were followed up by standardized maintenance procedures at baseline, first, third, and sixth months as with DI with adequate KTW (Control). Clinical parameters, peri-implant sulcular fluid (PISF) volume, PISF Interleukin 1β concentration, and bone loss were analyzed.

RESULTS

Significant improvements in clinical and immunological parameters were noted only for FGG for the whole study period. Statistical differences detected between the treatment groups (FGG vs M) were for gingival index at all time points and for PISF volume at sixth month. For the other parameters evaluated, while lower values were observed for FGG, statistically no differences were noted between the groups.

CONCLUSIONS

Based on the results of this study, it can be suggested that FGG performed around DIs lacking KT is a reliable method, leading to significant improvements in clinical and inflammatory parameters. Further long-term studies including more DIs are needed to clarify the role of KT on maintenance of DIs.

Biological factors involved in implant-anchored orthodontics and in prosthetic-implant therapy: a literature review

During the past few years, the application of orthodontic miniscrews and dental implants has been expanded. However, failures have necessitated ongoing investigation of potential risk factors. The aim of this overview was to conduct an assessment of the immunological response following application of cortical temporary anchorage devices--titanium miniscrew implants--in orthodontic patients. A scrupulous search of the database revealed only two matching items; therefore studies evaluating the immune response subsequent to insertion of dental implants were reviewed. Thorough assessment revealed the following as factors associated with dental implant rejection: (1) correlation of the volume of gingival and peri-implant crevicular fluid and the amount of interleukin (IL)-1beta with mucosal inflammation, thus serving as a peri-implantitis evaluation index; (2) significantly more frequent marginal bone loss around implants in patients with IL-1B-511 2/2 genotype; (3) humoral response to Staphylococcus aureus. However, since there is almost no evidence-based evaluation of the allergic/inflammatory reaction either to orthodontic titanium miniscrews themselves or in adolescents and young adults, who comprise the largest group of orthodontic patients, this issue requires further investigation. It is essential in order to achieve successful, sophisticated and modern treatment of malocclusions.