Peri-implant Crevicular Fluid Levels Research Articles

Peri-implant crevicular fluid and serum levels of soluble ST2 in peri-implant diseases: A pilot study.

Soluble ST2 (sST2) is a current biomarker of cardiovascular disease. It is used to predict susceptibility to cardiovascular diseases and to analyze their prognosis. Serum sST2 level increases in inflammatory diseases such as periodontitis. However, the level of sST2 in peri-implant diseases and crevicular fluid has not been investigated yet. Thus, the aim of this cross-sectional study is to analyze the level of sST2 in peri-implant health and diseases. Sixty-nine participants were divided into 3 groups as peri-implant health (PH), peri-implant mucositis (PM), and peri-implantitis (P-I). Peri-implant crevicular fluid (PICF) and serum samples were collected from each participant. The levels of sST2 and IL-6 in PICF and sST2, IL-6, and CRP in serum were compared between the groups. Pocket depth (PD), modified bleeding index (mBI), modified plaque index (mPI), keratinized mucosa index (KTW), and gingival/mucosal recession (REC) were recorded as clinical parameters. Biomarkers in the serum and PICF were analyzed by ELISA kit. Sixty-nine patients were included in the study. The differences in the following parameters were statistically significant between groups: age (p=.009), implant function time (p=.027), PD (p < .001), mBI (p < .001), mPI (p < .001), and KTW (p=.043). The PICF volume of P-I and PM groups were statistically higher than PH (p < .001). The amount of sST2 in P-I and PM groups were higher than PH (p=.043). Serum CRP was higher in the P-I group than in other groups (p=.034). There were no significant differences in serum sST2 (p=.247) and IL-6 (p=.110) levels between groups. The PICF levels of sST2 were significantly higher in PM and P-I groups compared to the healthy group. However, no significant difference was observed between the groups in terms of serum sST2 level.

Peri-implant crevicular fluid SIRT1 levels decrease in patients with peri-implant inflammatory: A prospective observational study

BackgroundA dental Implant is a prosthetic device made of alloplastic materials implanted into the bone to provide retention and support for a dental prosthesis. Sirtuin1 (SIRT1) molecule, a nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase, regulates a variety of physiological and pathological processes, including oxidative stress, metabolism, cell proliferation, cell differentiation, inflammatory, and apoptosis. We explored whether the expression of SIRT1 correlates in patients receiving implants with peri-implant mucositis (PIM) and peri-implantitis (PI) in comparison to patients with healthy peri-implant area (PIH). MethodsA number of 198 patients with dentition defects were enrolled in the study after their implants were functional for at least 6 months. All 198 subjects were divided into 3 groups: 1) control patients with PIH healthy implants; 2) patients with PIM mucositis; and 3) patients with PI implantitis. To distinguish these three groups, peri-implant crevicular fluid (PICF) was collected by inserting a sterile paper strip into the gap around the implant and the levels of SIRT1 and cytokines were measured by the enzyme linked immunosorbent assay (ELISA). Demographic and clinical data included age, sex, Body Mass Index (BMI), probing depth (PD), plaque index (PLI), bleeding on probing (BOP), oral health impact profile (OHIP-14), history of periodontitis and the use time of implants. ResultsThe PD, PLI, OHIP-14 evaluation scores in patients with periodontitis of PIM mucositis and PI implantitis were all significantly higher than in patients with PIH healthy implants. Overall, the SIRT1 levels in PICF of the PIM and PI patients were significantly lower than of the PIH patients. In comparison with PIM patients, SIRT1 levels of the PI patients were remarkably lower than the PIH patients. Pearson's analysis showed that SIRT1 levels were negatively correlated with levels of interleukin (IL)-6, C-reactive protein (CRP) and IL-1β in patients with PIM and PI. We suggest that SIRT1 levels could serve as a potential diagnostic biomarker of PI or PIM. The PICF levels of SIRT1, CRP, IL-6, IL-1β and the history of periodontitis were the risk factors for patients with peri-implant inflammatory process. ConclusionThe measurement of SIRT1 expression in PICF may serve as a biomarker for the ongoing inflammatory process in patients with dental implants. The low SIRT1 levels correlated with PI implantitis and PIM mucositis as well as the elevated levels of pro-inflammatory cytokines (CRP, IL-6 and IL-1β).

Peri-implant treatment reduces the salivary levels of Colony stimulator factor-1 and S100A8/A9.

This study evaluated the impact of peri-implant treatment in the salivary levels of Colony stimulator factor -1 (CSF-1), S100A8/A9 and S100A12 in patients having mucositis or peri-implantitis. As a secondary aim, we analysed the correlation between the salivary and peri-implant crevicular fluid (PICF) levels. Forty-seven patient, 27 having mucositis (mean age 63.11 ± 7.78) and 20 having peri-implantitis (61.25 ± 7.01) participated in the study. Clinical parameters, probing pocket depth, clinical attachment level, % of plaque and bleeding on probing were evaluated. Unstimulated whole saliva was collected from all patients, while PICF was collected only from a patient's subgroup (n = 20). Samples were collected before and 3months after peri-implant treatment. Enzyme-linked immunosorbent assays determined levels of CSF-1, S100A8/A9 and S100A12. Clinical parameters improved and salivary levels of CSF-1 and S100A8/A9, but not S100A12, reduced significantly after treatment in both groups. No significant correlation was found in the salivary and PICF levels of the same molecule. In conclusion, the treatment of peri-implant disease significantly improved the clinical parameters and reduced the salivary levels of CSF-1 and S100A8/A9. The salivary expressions of CSF-1, S100A8/A9 and S100A12 did not correlate with their own expression in PICF.

Influence of body fat in patients with dental implant rehabilitation treated with adjunctive photodynamic therapy.

Obesity appears to govern peri-implant hard and soft tissue health. We hypothesized that adjunctive photodynamic therapy (aPDT), improves clinical peri-implant perimeters and alleviates peri-implant crevicular fluid (PICF) levels of tumour necrosis factor (TNF)-α, interleukin (IL)-6 and high sensitivity C-reactive protein (hsCRP) in obese with moderate peri-implantitis. The current clinic-laboratory study aimed to determine whether obesity influences the outcomes of aPDT in patients with moderate peri-implantitis. A total of 49 patients (24 obese and 25 non-obese) with moderate periodontitis receiving aPDT were included. Clinical characteristics including peri-implant probing depth (PIPD), peri-implant bleeding on probing (PIBOP), and peri-implant plaque index (PIPI) were measured. PICF levels of TNF-a, IL-6 and hsCRP were assessed using enzyme-linked immunosorbent assay (ELISA). Both clinical and cytokine assessments were performed at baseline, three months and six months, respectively. Intra-group comparisons of changes in clinical parameters pre and post PDT was performed using Friedman test. Comparison of changes of TNF-a, IL-6 and hsCRP levels within group was performed using Kruskal-Wallis test. When compared with the baseline, a considerable reduction in PIPI, PIBOP and PIPD was observed in obese as well as non-obese patients at three- and six-months follow-up. At three months follow-up, a statistically significant difference was observed in PIPI (p < 0.05), PIBOP (p < 0.05) and PIPD (p < 0.05) among obese and non-obese individuals. Additionally, when compared with the baseline, a statistically significant difference was noticed in PICF volume (p < 0.05) and levels of TNF-α (p < 0.05) and IL-6 (p < 0.05) in non-obese as well as obese at three- and six-months follow-up. With the application of aPDT, considerable improvement was observed in peri-implant inflammatory parameters among obese and non-obese patients with moderate peri-implantitis. Obesity did not appear to influence aPDT outcome in patients with moderate peri-implantitis.

Effect of anatomical location (mandible vs maxilla) of dental implants on the BMP-2, BMP-7, sRANKL and OPG levels in periimplant crevicular fluid during osseointegration. A pilot study

Background:The aim of this study was to investigate levels of bone morphogenetic protein-2 (BMP-2), BMP-7, soluble receptor activator of nuclear factor-kB ligand (sRANKL) and osteoprotegerin (OPG) in the peri-implant crevicular fluid (PICF) of implants placed in both maxilla and mandible during the osseointegration period.Methods:Thirty-three patients (17 females and 16 males; mean age 47.03±11.23 years) were included in this study. A total of 33 implants were placed in both of maxilla (Group 1/n=18) and mandible (group 2/n=15). Peri-implant crevicular fluid (PICF) samples, modified plaque index (MPI), gingival index (GI) and probing depth (PD) measurements were obtained at 1 and 3 months after surgery. PICF levels of BMP-2/-7, sRANKL and OPG were analyzed by ELISA.Results:No complications were observed during the healing period. No significant differences were observed in the PICF levels of sRANKL, OPG, BMP-2 and BMP-7 and evaluated clinical parameters between groups at any time point (p&amp;gt;0.05). While PICF volume of group 2 was greater than group 1 at first month, PICF volume of group 1 was greater than group 2 at 3 months (p&amp;lt;0.05). There was a positive correlation between sRANKL levels and PICF volume (p&amp;lt;0.05) and a strong correlation between BMP-2 and BMP-7 (p&amp;lt;0.01).Conclusions:The results of this pilot study didn’t show any significant difference in PICF levels of BMP-2, BMP-7, sRANKL, and OPG in terms of anatomic location of dental implants. Further well-designed studies should be carried out to evaluate the relationship between bone related biomarkers and anatomic location of dental implants.

Clinical indices and local levels of inflammatory biomarkers in per-implant health of obese and nonobese individuals.

Obesity seem to regulate peri-implant health. It is proposed that peri-implant crevicular fluid (PICF) levels of interleukin (IL)-1β and IL-6 are higher in obese as compared to nonobese individuals. The purpose of the present clinico-laboratory study is to estimate and compare the clinical and radiographic indices and PICF levels of IL-1β and IL-6 among obese and nonobese patients. Fifty patients were divided into two groups (25 obese with ≥27.5 kg/m2 and 25 nonobese with <27.5 kg/m2 individuals). Clinical indices for both periodontal and peri-implant evaluating plaque index (PI), bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), and crestal bone loss (CBL) were recorded around teeth and implants. PICF was collected and assessed for the levels of IL-1β and IL-6 using enzyme-linked immunosorbent assay. A significant difference was observed in PI and BOP around natural teeth and implants in obese patients, respectively (P < .05). CBL was found to be significantly higher among obese as compared to nonobese patients (P = .022). Peri-implant and periodontal PD was higher in obese as compared to nonobese but did not reach statistical significance. Levels of IL-1β and IL-6 were statistically significantly higher among obese patients as compared to nonobese (P = .001). Pearson correlation analysis showed IL-1β was positively correlated with CBL (P = .0079), whereas IL-6 showed positive correlation with both BOP (P = .0019) and CBL (P = .015) among obese patients. Clinical peri-implant parameters were worse and proinflammatory biomarkers were significantly higher in obese patients compared with nonobese subjects. The findings of the present study suggests that increased proinflammatory biomarkers in PICF of obese patients may modulate peri-implant inflammation around dental implants.

Comparison of Clinical, Radiographic, and Immunologic Inflammatory Parameters Around Dental Implants with Cement-Retained and Screw-Retained Restorations: A 5-Year Prospective Cohort Study in Men

To compare bleeding on probing (BoP), probing depth (PD; ≥ 4 mm), radiographic (peri-implant crestal bone loss [CBL]), and immunologic inflammatory (interleukin-1beta [IL-1β] and matrix metalloproteinase-9 [MMP-9]) parameters around dental implants with cement-retained (CR) and screw-retained (SR) implant-supported crowns. Based on the mode of retention of the restoration, 51 patients were divided into two groups: Group 1, consisting of 26 single implants restored with CR crowns, and Group 2, consisting of 25 single implants restored with SR crowns. Peri-implant BoP, PD, and CBL were scored, and levels of IL-1β and MMP-9 in the peri-implant crevicular fluid (PICF) in both groups were measured in duplicate using enzyme-linked immunosorbent assay. Full-mouth mechanical debridement was performed biannually in both groups. Statistical analysis was performed using Kruskal-Wallis test with the significance level set at P < .05. The mean CBL among implants in groups 1 and 2 was 1.7 ± 0.5 mm and 1.7 ± 0.4 mm, respectively. There was no statistically significant difference in mean BoP, PD, and CBL among implants in both groups (P > .05). There was no statistically significant difference between groups 1 and 2 in the PICF levels of IL-1β (7.3 ± 0.5 and 7.2 ± 0.5, respectively) and MMP-9 (165 ± 9.4 and 182 ± 10.6, respectively) (P > .05). The mode of retention of implant-supported crowns does not appear to affect their clinical correlations with BoP, PD, CBL, and levels of IL-1β and MMP-9 in the PICF when zinc oxide eugenol cement is used.

Cytokine and microbial profiles in relation to the clinical outcome following treatment of peri‐implantitis

To study whether cytokine levels and bacterial counts in p atients with peri-implantitis reflect clinical treatment outcome following non-surgical management. Luminex magnet bead technology and checkerboard DNA-DNA hybridization were used to assess treatment outcome after treatment at the implant with the most severe peri-implantitis in 41 participants. Study group mean age was 40.3years (SD±9.9). Stable treatment outcome after 6months (no further bone loss, probing pocket depth decrease ≥0.5mm, no bleeding/suppuration) was identified in 9 of 41 (22%) participants. Peri-implant crevicular fluid (PICF) levels were also lower for Il-1β (P<0.01), and with trends of lower cytokine levels in PICF for TNF-α (P=0.071), PDGFBB (P=0.071), as well as for VEGF (vascular endothelial growth factor) (P=0.071), and bacterial counts for Actinomyces israelii, Aggregatibacter actonomycetemcomitans (Y4), Campylobacter gracilis, Echerichia coli, Fusobacterium periodonticum, Leptotrichia buccalis, Parvimonas micra, Staphylococcus haemolyticus, Streptococcus anginosus, and Tannerella forsythia. Increasing levels of IL-1 β and S.aureus (r2 =0.856) were found only at implants with non-stable outcome. A reduction of PICF levels for selected cytokines and bacteria studied had a sensitivity of 0.77, and a specificity of 0.80 against the clinical outcome as gold standard. Data analysis failed to differences in treatments (PerioFlow® versus YAG: ER laser) for changes in the expression of cytokines and bacteria studied. At 6months, clinically stable treatment outcome of peri-implantitis is associated lower levels of putative pathogens total bacterial load with ≥30% reduction of IL1-β, L-6, and VEGF levels in PICF.

Could cytokine levels in the peri-implant crevicular fluid be used to distinguish between healthy implants and implants with peri-implantitis? A systematic review.

Despite investigative efforts to identify the levels of different types of cytokines in the peri-implant crevicular fluid (PICF), the efficacy of these biomarkers in assisting the diagnosis of peri-implantitis is still undetermined. This systematic review aimed to answer the following question: "Could cytokine levels in the PICF be used to distinguish between healthy implants and implants with peri-implantitis?" This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE and EMBASE databases were searched from 1990 up to and including March 2015, using MeSH terms and other keywords. Additional publications were searched using a hand search of reference lists of relevant studies. Titles and abstracts were screened and papers that fulfilled eligibility criteria were assessed. Out of 1212 titles, 18 studies reporting the levels of nine different cytokines were included. Proinflammatory cytokines [interleukin (IL)-1β, IL-6, IL-12, IL-17 and tumor necrosis factor-α) were the cytokines studied most commonly, followed by anti-inflammatory cytokines (IL-4 and IL-10), osteoclastogenesis-related cytokines (RANKL) and chemokines (IL-8). Nine studies reported statistically significantly higher levels of proinflammatory cytokines in the PICF of implants with peri-implantitis than in the PICF of healthy implants. Most studies did not find any significant differences in the PICF levels of anti-inflammatory cytokines and RANKL between healthy implants and implants with peri-implantitis. IL-8 was the only chemokine studied and its levels did not differ significantly between healthy and diseased implants. The studies differed greatly in the manner in which they reported the results (e.g. concentrations or total amounts) and in the exclusion of confounders, such as smoking. The results of this systematic review indicate moderate evidence in the literature to support that implants with peri-implantitis present higher levels of proinflammatory cytokines in the PICF than do healthy implants. Evidence regarding the PICF levels of anti-inflammatory cytokines, osteoclastogenesis-related cytokines and chemokines as possible predictors of peri-implantitis is too limited.

Protein biomarkers and microbial profiles in peri-implantitis.

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. 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. The mean concentration of IL-1β (44.6 vs. 135.8pg/ml; P<0.001), TIMP-2 (5488.3 vs. 9771.8pg/ml; P=0.001), VEGF (59.1 vs. 129.0pg/ml; P=0.012), and OPG (66.5 vs. 111.7pg/ml; P=0.050) was increased in the peri-implantitis patients. The mean expression of MMP-8 (6029.2 vs. 5943.1pg/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. 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.

Monitoring bone morphogenetic protein‐2 and ‐7, soluble receptor activator of nuclear factor‐κB ligand and osteoprotegerin levels in the peri‐implant sulcular fluid during the osseointegration of hydrophilic‐modified sandblasted acid‐etched and sandblasted acid‐etched surface dental implants

The implant surface plays a major role in the biological response to titanium dental implants. The aim of this study was to investigate levels of soluble receptor activator of nuclear factor-κB ligand (sRANKL), osteoprotegerin (OPG), bone morphogenetic protein-2 (BMP-2) and -7 (BMP-7) in the peri-implant crevicular fluid (PICF) of different implants during the osseointegration period. Forty-seven patients (22 females and 25 males, mean age 47.34 ± 10.11) were included in this study. Forty-seven implants from two implant systems (group A1 (sandblasted acid-etched [SLA]-16), group A2 (hydrophilic-modified SLA [SLActive]-16), and group B (sandblasted acid-etched [SLA]-15) were placed using standard surgical protocols. PICF samples, plaque index, gingival index and probing depth measurements were obtained at 1 and 3 mo after surgery. PICF levels of sRANKL, OPG, BMP-2/-7 were analyzed by ELISA. No complications were observed during the healing period. No significant differences were observed in the PICF levels of sRANKL, OPG, BMP-2 and BMP-7 for all groups at any time point (p > 0.05). A significant decrease was observed in BMP-2 levels in group A1 (p < 0.05). A significant increase in BMP-7 levels was observed only for group A2 (p < 0.05). There was a strong negative correlation between OPG and gingival index and a negative correlation between BMP-7 and plaque index (p < 0.05). Considering the correlations between clinical and biochemical parameters, the levels of these cytokines in PICF during early healing of implants reflects the degree of peri-implant inflammation, rather than differences in the implant surfaces.

Receptor activator of nuclear factor kappa B ligand (RANKL) levels in peri-implant crevicular fluid.

Receptor activator of nuclear factor kappa B ligand (RANKL) is one of the key cytokines in the induction of osteoclastogenesis both in vitro and in vivo. Several reports indicated the presence of sRANKL in gingival crevicular fluid of patients with periodontal diseases. To determine the presence of RANKL in peri-implant crevicular fluid samples of implants with peri-implantitis, peri-implant mucositis and healthy controls. In this study, 40 implants were categorized as clinically healthy, peri-implant mucositis and peri-implantitis according to the clinical and radiographic findings. Filter paper strips were used to collect peri-implant crevicular fluid for 30 seconds in the base of the crevice/pocket. Peri-implant crevicular fluid (PICF) samples were obtained from buccal and lingual aspects of implants. Plaque index, probing depth, gingival index and bleeding on probing were recorded at six sites per implant. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the PICF levels of sRANKL. There were no statistically significant differences in sRANKL concentration between healthy group, peri-implant mucositis and periimplantitis (p=0.12). There were also no statistical correlation between the concentration of sRANKL and probing pocket depth (R=0.051, p=0.65), or any of the other clinical regarding (p>0.05). No differences between the mean sRANKL concentration in the buccal and lingual sites were found (p=0.693). Our results may suggest that peri-implant crevicular fluid analysis of sRANKL in conjunction with some other osteoclastogenic mediators could be further investigated in further well-designed prospective longitudinal studies on a larger-scale sample size in the evaluation of dental implants.

Proinflammatory cytokines (IL-1β and TNF-α) and chemokines (IL-8 and MIP-1α) as markers of peri-implant tissue condition

Analysis of peri-implant crevicular fluid (PICF) offers a non-invasive means of studying the host response in peri-implant disease and may provide an early indication of patients at risk for active disease. This study examined the PICF levels of interleukin-1beta (IL-1beta), tumour necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8) and macrophage inflammatory protein-1alpha (MIP-1alpha) in patients with non-manifesting inflammation, early and late stages of mucositis. The study group comprised 90 adult healthy volunteers with endosseal titanium implants inserted. Samples were taken from peri-implant sulcus using a filter paper technique. Implant tissues were categorized clinically as healthy, early mucositis or advanced mucositis. Clinical manifestations were determined by: gingival index and bleeding on probing, plaque index and radiographic analyses. Cytokine concentrations were assesed using commercially available enzyme-linked immunosorbent assay kits. Patients from the control group (healthy patients) have significantly lower concentrations of IL-1beta, TNF-alpha, IL-8 and MIP-1alpha in PICF compared with both groups with mucositis. Positive correlation was noted in the control group between IL-1beta and TNF-alpha and between MIP-1alpha and IL-8 in the group with early mucositis. The results suggest that cytokines could be prognostic markers of implant failure.

Osteoprotegerin levels in peri‐implant crevicular fluid

To evaluate the levels of soluble receptor activator of nuclear factor-kappaB ligand (sRANKL) and osteoprotegerin (OPG) in crevicular fluid of endosseous dental implants. Eighty-six implants in 39 patients were evaluated. All patients were treated with root-type implants placed at least 16 months and loaded at least 12 months before the examination. Peri-implant crevicular fluid (PICF) samples were obtained from buccal and lingual aspects of implants. Modified plaque index, probing depth, gingival index, and bleeding on probing (BOP) were recorded at four sites per implant. PICF levels of sRANKL and OPG were analysed by ELISA. Spearman's correlations were utilised to relate biochemical data and clinical parameters. The PICF level of sRANKL did not show significant correlation with the clinical parameters or the OPG level. The total amount of OPG was positively correlated with PICF volume, gingival index, and BOP (P<0.05) and negatively correlated with pack years (P<0.05). The findings of this preliminary study suggest that the crevicular fluid level of OPG deserves further investigation as a possible marker to evaluate the health status of surrounding tissues of dental implants, as this was not the case for the sRANKL level. Larger scale studies, particularly in peri-implantitis cases, may shed more light on this subject.

Interleukin-1beta, tumor necrosis factor-alpha levels and neutrophil elastase activity in peri-implant crevicular fluid.

The aim of this study was to determine interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) levels and neutrophil elastase (NE) activity in peri-implant crevicular fluid (PICF) of smoker and nonsmoker patients, and to investigate their relationships with clinical parameters. A total of 42 endosseous root-form dental implants of 14 patients were clinically examined by modified Plaque index (PI), modified Gingival index (GI) and probing depth (PD). Smoking habits of the patients were recorded. PICF of implants were collected by Periopaper strips and IL-1beta, TNF-alpha levels were determined by enzyme-linked immunosorbent assay (ELISA). NE was analyzed with a neutrophil specific chromogenic substrate, N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroanilide. The cytokine and enzyme levels in PICF were expressed as total amount/activity and as concentrations. NE activity in PICF significantly correlated with GI and PD, and IL-1beta levels with GI and PICF volume (P < 0.05). The correlations were stronger when the PICF levels were expressed as total IL-1beta amount and as total NE activity. The implants with inflamed gingiva (GI > 1) had higher levels of IL-1beta and NE activity than implants with noninflamed or slightly inflamed gingiva (GI <or= 1) (P < 0.05). Total NE activity in implants with deep pockets (PD > 3 mm) was greater than the implants with shallow pockets (PD <or= 3 mm) (P < 0.05). The implants of smoker patients had significantly lower PICF NE activity and IL-1beta levels, and significantly higher TNF-alpha levels than the implants of nonsmokers (P < 0.05). The findings of the present study indicate that NE activity and IL-1beta levels in PICF may be used to measure implant health status of patients who do not smoke.