Crevicular fluid analysis around two failing dental implants: a clinical report

Host response and peri-implantitis

Considering the absence of predictable and effective therapeutic interventions for the treatment of peri-implantitis, scientific evidence concerning the host response profile around dental implants could be important for providing in the future a wider preventive and/or therapeutic window for this peri-implant lesion, indicating biomarkers that provide quantifiable measure of response to peri-implant therapy. Moreover, a better knowledge of pattern of host osteo-immunoinflammatory modulation in the presence of peri-implantitis could either benefit the early diagnostic of the disease or to cooperate to prognostic information related to the status of the peri-implant breakdown. Finally, new evidences concerning the host profile of modulators of inflammation and of osseous tissue metabolism around dental implants could explain the individual susceptibility for developing peri-implant lesions, identifying individuals or sites with increased risk for peri-implantitis. The focus of this chapter was, based on a systematically searched and critically reviewed literature, summarizing the existing knowledge in the scientific research concerning the host osteo-immunoinflammatory response to the microbiological challenge related to periimplantitis.

Interleukin-1β level in peri-implant crevicular fluid and its correlation with the clinical and radiographic parameters

Background and Objectives:

Assessing only the clinical and radiographic parameters for evaluation of dental implants may not be enough as they often reflect extensive inflammatory changes in the periodontal tissues. As peri-implant crevicular fluid (PICF) can give us a more prompt and objective measure of the disease activity, the purpose of this case series is to assess the peri-implant health status of single tooth dental implants not only clinically and radiographically but also biochemically.

Materials and Methods:

Thirteen patients were subjected to dental implants at single edentulous sites using a conventional surgical approach. At baseline, 6 months, and 12 months after implant placement, the clinical and radiographic parameters were recorded. Additionally, IL-1β in PICF was estimated using the ELISA kit at 6^th and 12^th month.

Results:

The clinical and radiographic parameters differed significantly around the implants at different time intervals with IL-1β levels showing highly significant differences between 6 months (31.79 ± 12.26 pg/μl) and 12 months (113.09 ± 51.11 pg/μl). However, Spearman's correlation coefficient showed no correlation with the clinical and radiographic parameters.

Interpretation and Conclusion:

Assessment of the various parameters confirmed that all the implants had a healthy peri-implant status. Although the levels of IL-1β in PICF were elevated at the 12^th month, they were well within the healthy range as observed by previous studies. This indicates that IL-1β, a biochemical marker, can be used as an adjunct to clinical and radiographic parameters in the assessment of EARLY inflammatory changes around implants.

Cellular populations of periimplant tissues: cytological analysis with sulcular microbrushing

PURPOSE

Cellular populations of gingival crevicular fluid cytological analysis of integrated implants sites have been investigated by using sulcular cytological brushing, as a means of providing an objective and reproducible technique for monitoring periimplant tissue health.

MATERIALS AND METHODS

A total of 60 patients with osteointegrated implants bearing at least for 2 years were divided in 2 groups, A and B. Group A consisted of 30 subjects who presented scarce oral hygiene. In Group B, 30 subjects with a good oral hygiene were included.

RESULTS

Comparative analysis of the data obtained by sulcular microbrushing of the 2 groups put into evidence significative differences in the expression of the microbiological and the cytological parameters.

CONCLUSION

Clinical monitoring of parodontal and periimplant tissues makes use of several diagnostic tests ranging from clinical and radiological tests to biological assays. However, none of these techniques allows to evaluate periimplant tissue cytological status. This preliminary study suggested sulcular microbrushing might be a useful tool in the early diagnosis and in the micrological monitoring of peri-implantitis.

OPG and RANKL levels around miniscrew implants during orthodontic tooth movement

INTRODUCTION

The aim of this study was to determine the peri-miniscrew implant crevicular fluid receptor activator of nuclear factor-кB ligand (RANKL) and osteoprotegerin (OPG) levels around loaded and unloaded miniscrew implants at different time intervals.

METHODS

Twenty loaded and 16 unloaded miniscrew implants were included in this study. All miniscrew implants were placed bilaterally between the maxillary second premolars and first molars as anchorage units for canine distalization. Peri-miniscrew implant crevicular fluid was taken from the mesiobuccal aspects of the loaded and unloaded miniscrew implants before loading; at 24, 48, and 168 hours; and on day 30 after force application. Enzyme-linked immunosorbent assay kits were used to determine RANKL and OPG levels in the peri-miniscrew implant crevicular fluid samples. Wilcoxon, Mann-Whitney U, and Spearman correlation tests were used for statistical evaluations at the P <0.05 level.

RESULTS

Although the total amount of OPG was not different between the groups, the total amount of RANKL was significantly elevated in the loaded miniscrew implant group (P <0.05) at all time periods. Peri-miniscrew implant crevicular fluid volume was the highest at 48 hours in the loaded group. Also, the OPG/RANKL ratio in the peri-miniscrew implant crevicular fluid was significantly decreased in the loaded miniscrew implant group.

CONCLUSIONS

The OPG and RANKL levels vary around loaded and unloaded miniscrew implants as a result of force application.

Cytokines in pathogenesis of peri-implantitis

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Tumor necrosis factor-alpha levels after surgical anti-infective mechanical therapy for peri-implantitis: a 12-month follow-up

BACKGROUND

The aim of the present case series was to evaluate the effects of a surgical anti-infective mechanical therapy for peri-implantitis on clinical parameters and tumor necrosis factor-alpha (TNF-alpha) levels at 12 months post-therapy.

METHODS

Ten patients with peri-implantitis were treated with open surgical debridement, abrasive sodium carbonate air-powder, and resin curets. Clinical parameters were recorded before and 3 and 12 months after therapy. At these time points, the total amounts of TNF-alpha in the peri-implant crevicular fluid were measured by enzyme-linked immunosorbent assay.

RESULTS

At 3 and 12 months, the anti-infective therapy resulted in significant improvements in all clinical parameters (P <0.05). Moreover, the total amount of TNF-alpha was significantly reduced at 3 and 12 months after therapy compared to baseline (P <0.05), paralleling the changes in mean probing depth and bleeding on probing.

CONCLUSION

The anti-infective mechanical therapy reduced the crevicular levels of TNF-alpha in sites affected by peri-implantitis over a period of 12 months, and this phenomenon was associated with improvements in clinical parameters.

Association of the composite IL-1 genotype with peri-implantitis: a systematic review

OBJECTIVE

Cytokine gene polymorphisms may modulate the host response to the bacterial challenge and influence susceptibility to peri-implantitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A (-889) and in IL-1B (+3953), and peri-implantitis.

MATERIAL AND METHODS

An electronic search in the National Library of Medicine-computerized bibliographic database MEDLINE and a manual search were performed. The search was conducted for longitudinal clinical trials comparing progression of peri-implantitis in IL-1 genotype positive (carrying allele 2) with IL-1 genotype negative (not carrying allele 2) subjects. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 44 titles of which two longitudinal publications were included.

CONCLUSION

Based on the findings from this study, there is not enough evidence to support or refute an association between the IL-1 genotype status and peri-implantitis. Systematic genetic testing for the assessment of the risk of peri-implantitis cannot be recommended as a standard of care at this time.

Characteristics of collagenase-2 from gingival crevicular fluid and peri-implant sulcular fluid in periodontitis and peri-implantitis patients: pilot study

OBJECTIVE

To compare collagenase activity and collagenolytic matrix metalloproteinase (MMP) levels in gingival crevicular fluid (GCF) and in peri-implant sulcular fluid (PISF) in gingivitis (G), chronic periodontitis (CP), and peri-implantitis (PI) human subjects.

MATERIAL AND METHODS

GCF and PISF were collected on filter paper strips, volume was determined, and samples were extracted in buffer containing general proteinase but not MMP inhibitors. Collagenase activity was measured using a DNP-synthetic octapeptide, and molecular and activation forms of collagenase-2 by Western immunoblotting.

RESULTS

GCF from CP and G sites exhibited elevated collagenase activity and flow, but collagenase concentrations expressed per microl were not significantly different between the healthy and G sites. Minimal fluid was obtained from healthy PISF, and collagenase concentration was the same or lower than in healthy GCF. Although PISF flow was 34% lower than GCF flow in CP subjects, collagenase concentration in CP and in PI sites was 78% and 971% greater, respectively, than in the appropriate healthy sites. Western immunoblot revealed MMP-8 in both PISF and GCF; fibroblast-type MMP-8 was not detected in healthy GCF and PISF. Immunoreactivity level and inactive and activated forms of PMN-type MMP-8 in GCF and PISF increased with the severity of periodontitis and peri-implantitis. Enhanced levels of fibroblast-type MMP-8 in active form were detected only in severe CP GCF and PI PISF.

CONCLUSIONS

Peri-implantitis PISF contained higher collagenase-2 levels and activity than GCF from similar deep CP sites. GCF and PISF from severe CP and PI exhibited the highest activation of MMP-8 isoenzymes species (PMN and fibroblast-type).

Interleukin 1beta levels around microscrew implants during orthodontic tooth movement

OBJECTIVE

To determine whether interleukin 1beta (IL-1beta) levels are elevated around microscrew implants that are used as anchorage for tooth movement.

MATERIALS AND METHODS

Ten young adults, aged 16.3 +/- 2.5 years and with all four premolars extracted , comprised the study group. Twenty maxillary microscrew implants were placed bilaterally in the alveolar bone between the maxillary second premolars and first molars as anchorage units for distal movement of the maxillary canines. The maxillary canines served as the treatment group, and the microscrew implants were designated as the implant group. The mandibular canines were used as controls. Peri-microscrew implant crevicular fluid (MICF) and gingival crevicular fluid (GCF) were collected at the beginning of tooth movement (2 weeks after implant placement); at 24, 48, and 168 hours later; and on days 14 and 21. An automated enzyme immunoassay was used to measure 1L-1beta in the MICF and the GCF.

RESULTS

The mean 1L-1beta level in the treatment group was significantly elevated at 24 hours (P = .003 < .05) and 48 hours (P = .003 < .05), whereas the levels in the control and implant groups did not change significantly during the experimental period. Also, the mean 1L-1beta level of the treatment group was significantly higher that in both the control and implant groups at 24 and 48 hours.

CONCLUSIONS

The microscrew implants did not demonstrate increased 1L-1beta levels during tooth movement. This supports the concept that microscrew implants might be useful as absolute anchorage devices.

Comparison of clinical, radiographic and immunological parameters of teeth and different dental implant platforms

A comparison between host response in teeth and dental implants was not made. Likewise, the association between host response and periodontal parameters has never been explored. The purpose of this study was to compare periodontal health around natural teeth and dental implants with different restorative platforms. Twenty-seven partially edentulous patients with dental implants, either external hex butt joint (n=28) or tapered Morse (n=45), were included in this study. Implants were in function for 1-6 years (mean 2.9). Plaque index (PI), gingival index (GI), probing depth (PD); and clinical attachment level (CAL), were recorded at final examination; alveolar bone loss (ABL) was measured at baseline and final examination using panoramic radiographs. Gingival crevicular fluid samples were obtained from the Ramfjord index teeth and all implants and assayed using enzyme-linked immunosorbent assay for prostaglandin E(2) (PGE(2)), interleukin-1 (IL-1) and tumour necrosis factor alpha (TNFalpha). Differences between teeth and implants and between the two implant platforms were compared using Student's t-test. Correlations between cytokines, ABL and clinical parameters were analyzed using Pearson's co-efficient test. PI and GI were significantly higher in teeth than dental implants (1.2+/-0.5 vs. 0.8+/-0.5, P=0.0018; 1.2+/-0.3 vs. 1.1+/-0.3, P=0.048). Conversely, PD was deeper in implants (2.66+/-0.6 vs. 3.66+/-0.9, P=0.001). GI and PD around teeth and implants were positively associated (R=0.561, P=0.0023; R=0.39, P=0.0452). Greater ABL was observed around dental implants (1.62+/-2.2 mm) compared with teeth (0.49+/-0.3 mm). A positive correlation was found between both IL-1 (R=0.73, P=0.0064; R=0.52, P=0.0081) and TNFalpha (R=0.64, P=0.0246; R=0.46, P=0.091) and ABL in teeth and implants. Both implant platforms were similar clinically and radiographically; however, TNFalpha (2.49+/-0.3 vs. 4.79+/-0.5, P=0.004) and IL-1 (24.52+/-7.3 vs. 45.41+/-9.9, P=0.095) were higher for the non-submerged implants. In conclusion, IL-1 and TNFalpha are sensitive markers of ABL around teeth and implants. The two dental implant platforms showed a similar clinical and radiographic response; however, the greater host response in the non-submerged implants might suggest future bone loss.

Actinobacillus actinomycetemcomitans Y4 capsular polysaccharide induces IL-1beta mRNA expression through the JNK pathway in differentiated THP-1 cells

Capsular polysaccharide from Actinobacillus actinomycetemcomitans Y4 (Y4 CP) induces bone resorption in a mouse organ culture system and osteoclast formation in mouse bone marrow cultures, as reported in previous studies. We also found that Y4 CP inhibits the release of interleukin (IL)-6 and IL-8 from human gingival fibroblast (HGF). Thus Y4 CP induces various responses in localized tissue and leads to the secretion of several cytokines. However, the effects of Y4 CP on human monocytes/macrophages are still unclear. In this study, THP-1 cells, which are a human monocytic cell line, were stimulated with Y4 CP, and we measured gene expression in inflammatory cytokine and signal transduction pathways. IL-1beta and tumour necrosis factor (TNF)-alpha mRNA were induced from Y4 CP-treated THP-1 cells. IL-1beta mRNA expression was increased according to the dose of Y4 CP, and in a time-dependent manner. IL-1beta mRNA expression induced by Y4 CP (100 microg/ml) was approximately 7- to 10-fold greater than that in the control by real-time PCR analysis. Furthermore, neither PD98059, a specific inhibitor of extracellular signal-regulated kinase nor SB203580, a specific inhibitor of p38 kinase prevented the IL-1beta expression induced by Y4 CP. However, JNK Inhibitor II, a specific inhibitor of c-Jun N-terminal kinase (JNK) prevented the IL-1beta mRNA expression induced by Y4 CP in a concentration-dependent manner. These results indicate that Y4 CP-mediated JNK pathways play an important role in the regulation of IL-1beta mRNA. Therefore, Y4 CP-transduced signals for IL-1beta induction in the antibacterial action of macrophages may provide a therapeutic strategy for periodontitis.

Microbiological findings and host response in patients with peri-implantitis

The aim of the present study was to characterise microbiota and inflammatory host response around implants and teeth in patients with peri-implantitis. We included 17 partly edentulous patients with a total of 98 implants, of which 45 showed marginal bone loss of more than three fixture threads after the first year of loading. Nineteen subjects with stable marginal tissue conditions served as controls. Oral hygiene, gingival inflammation, and probing pocket depth were evaluated clinically at teeth and implants. Microbiological and crevicular fluid samples were collected from five categories of sites: 1) implants with peri-implantitis (PI), 2) stable implants (SI) in patients with both stable and peri-implantitis implants, 3) control implants (CI) in patients with stable implants alone, 4) teeth in patients (TP) and 5) controls (TC). Crevicular fluid from teeth and implants was analysed for elastase activity, lactoferrin and IL-1 beta concentrations. Elastase activity was higher at PI than at CI in controls. Lactoferrin concentration was higher at PI than at SI in patients with peri-implantitis. Higher levels of both lactoferrin and elastase activity were found at PI than at teeth in patients. The concentrations of IL-1 beta were about the same in the various sites. Microbiological DNA-probe analysis revealed a putative periodontal microflora at teeth and implants in patients and controls. Patients with peri-implantitis harboured high levels of periodontal pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus and Treponema denticola. These findings indicate a site-specific inflammation rather than a patient-associated specific host response.

Elastase, alpha2-macroglobulin and alkaline phosphatase in crevicular fluid from implants with and without periimplantitis

The aim of this investigation was to determine the presence of selected enzymes and enzyme inhibitors in crevicular fluid collected from implants with and without clinical, radiographic and microbiological signs of periimplantitis. Eleven implants with symptoms of periimplantitis in eight patients (four men and four women) were compared to eleven implants in seven subjects (one man and six women) without periimplantitis. Periimplant crevicular fluid (PICF) was collected at the mesial and distal sites of each implant. Alkaline phosphatase activity (ALP) was measured by using p-nitrophenyl-phosphate as substrate, elastase activity (EA) by the use of a low molecular weight fluorogenic substrate, and the inhibitor alpha2-macroglobulin (alpha2M) by ELISA. ALP, EA and alpha2M were detected in the majority of samples in both groups. In comparison to the clinically healthy implants, total amounts of each of these substances were significantly higher in PICF collected around implants with periimplantitis. The mean total amounts of EA, alpha2M and ALP in the healthy group were: EA: 1.8 ng, alpha2M: 3.1 ng, ALP: 24.1 U, and in the periimplantitis group EA: 23.1 ng, alpha2M: 25.2 ng and ALP: 142.3 U. In addition, all three mediators were correlated with the clinical parameters. The results confirm the similarity of the inflammatory response of tissues surrounding implants and natural teeth, and suggest that ALP and EA could be promising markers of bone loss around dental implants.