Analysis of the inflammatory process around endosseous dental implants and natural teeth: myeloperoxidase level and nitric oxide metabolism

PURPOSE: The aim of the present study was to analyze the 2 molecular measures of inflammation: (1) the nitrite, an end metabolite of nitric oxide (NO) oxidation and (2) myeloperoxidase (MPO). Both are found in peri-implant sulcus fluid (PISF) of implants and gingival crevicular fluid (GCF) of natural teeth in healthy or diseased states. MATERIALS AND METHODS: A total of 109 tooth or dental implant sites, either healthy/noninflamed, inflamed (Gingival Index [GI] > 0), or affected by periodontitis, were classified, and GCF/PISF samples were obtained. GCF/PISF MPO and nitrite levels were spectrophotometrically determined. For comparison of clinical parameters and PISF/GCF nitrite and MPO levels, Kruskal-Wallis analysis followed by Mann-Whitney test with Bonferroni correction was performed. Healthy/noninflamed, slightly inflamed, moderate/severely inflamed sites were also analyzed using the Kruskal-Wallis test followed by the Mann-Whitney test with Bonferroni correction. The correlation between nitrite and MPO levels and clinical inflammatory status were analyzed with Spearman's correlation coefficient. RESULTS: Clinical parameters, including both the GCF and PISF volumes, demonstrated gradual increases with the presence of gingival/peri-implant inflammation (P < .05). Despite the higher PISF than GCF volume at healthy sites (P = .001), there were no volumetric differences at inflamed sites (P = .771). PISF from inflamed sites (P = .025) and GCF from gingivitis and periodontitis sites presented higher total MPO levels (P < .05) than samples from noninflamed sites. Despite the relatively stable GCF nitrite levels at healthy and diseased sites, PISF from inflamed sites had higher nitrite content than noninflamed sites (P < .05). CONCLUSIONS: The present study demonstrated the volumetric similarities of PISF and GCF in terms of response to inflammation. However, some differences between the 2 biochemical measures of inflammation and their presence in PISF and GCF were also observed. PISF is likely to have a considerable diagnostic potential for reflecting the biologic changes around load-bearing endosseous dental implants. (Cohort Study) (More than 50 references.)     

Analysis of cathepsin-K activity at tooth and dental implant sites and the potential of this enzyme in reflecting alveolar bone loss

Background: Cathepsin‐K is an enzyme involved in bone metabolism which may make this feature important for both natural teeth and dental implants. The aims of the present study are to comparatively analyze the gingival crevicular fluid (GCF)/peri‐implant sulcus fluid (PISF) cathepsin‐K levels of natural teeth and dental implants, and to assess the potential relationship between this biochemical parameter and alveolar bone loss around natural teeth and dental implants. Methods: Probing depth, bleeding on probing, gingival index, and plaque index clinical parameters were assessed, and GCF/PISF samples were obtained from natural teeth/dental implants presenting with either clinical health, gingivitis/peri‐implant mucositis, or chronic periodontitis/peri‐implantitis. Cathepsin‐K activity levels of 42 GCF samples and 54 PISF samples were determined, and marginal bone loss (MBL) measures were calculated from digitalized standardized intraoral periapical radiographs obtained from natural teeth and dental implants by using cemento‐enamel junction and the actual distance between two consecutive threads of the dental implant as reference points for natural teeth and dental implants, respectively. Results: Comparing the natural teeth group with dental implant group with regard to MBL measure, cathepsin‐K activity, and GCF/PISF volume revealed no significant differences. In both natural teeth and dental implant groups, despite higher MBL measures, cathepsin‐K activity, and GCF/PISF volumes with the presence of inflammation, it was the presence of alveolar bone loss that lead to significantly higher values for these parameters. Conclusion: We suggest cathepsin‐K as a biochemical parameter for monitoring periodontal/peri‐implant alveolar bone loss.     

A Cross‐Sectional Assessment of Biomarker Levels Around Implants Versus Natural Teeth in Periodontal Maintenance Patients

Background: Recent studies point to the clinical utility of using peri‐implant sulcular fluid (PISF) as a valuable diagnostic aid for monitoring peri‐implant tissue health. The objectives of this study are to determine the levels of key biomarkers in PISF in periodontal maintenance participants and compare them with their corresponding levels in gingival crevicular fluid (GCF) obtained from the same participants. Methods: PISF and GCF were collected from an implant and a contralateral natural tooth after the clinical examination of 73 participants. The levels of interleukin (IL)‐1α, IL‐1β, IL‐6, IL‐8, IL‐10, IL‐12, IL‐17A, tumor necrosis factor (TNF)‐α, C‐reactive protein, osteoprotegerin, leptin, and adiponectin were determined using multiplex proteomic immunoassays. The correlation of biomarker concentrations between GCF versus PISF, within GCF or PISF, and with several covariates (age, brushing frequency, days since professional cleaning, probing depth [PD], and plaque index) were also determined. Results: Significantly higher levels of IL‐17A (P = 0.02) and TNF‐α (P = 0.03) were noted in PISF when compared with their levels in GCF. Significant positive correlations were noted between the concentrations of cytokines in PISF versus their levels in GCF. Among the covariates, a significant positive correlation was noted between mean PDs around implants and levels of IL‐1β (P <0.05) and IL‐8 (P <0.05) in PISF. Conclusion: The results of this study point to the differential expression of specific biomarkers in GCF versus their levels in PISF in periodontal maintenance patients, which is critical information before establishing PISF as a diagnostic fluid to monitor peri‐implant health.     

Analysis of thte possible impact of inflammation severity and early and delayed loading on nitric oxide metabolism around dental implants

PURPOSE: The aim of the present study was to analyze the possible impact of clinical status, presence and severity of inflammation, and loading on nitric oxide (NO) metabolism around mandibular dental implants. MATERIALS AND METHODS: A total of 34 implants in 17 patients, loaded either early (EL) or after a delay (DL), were classified according to the presence and severity of clinical inflammation in the peri-implant sites. Clinical parameters were recorded, peri-implant sulcular fluid (PISF) samples were obtained, and PISF nitrite levels were spectrophotometrically determined. Clinical measurements and nitrite analysis were repeated at 1, 3, 6, and 9 months postloading at available sites. RESULTS: Compared to noninflamed sites, inflamed sites demonstrated higher mean total nitrite levels (P = .032) that tended to increase with the severity of inflammation at both EL and DL implants. At noninflamed sites, EL implants provided significantly higher PISF volume than DL implants (P = .001). At noninflamed sites, EL implants revealed higher total nitrite levels; on the contrary, at inflamed sites, DL implants revealed higher total nitrite levels. In general, nitrite levels demonstrated a pattern of decrease followed by an increase during follow-up. DISCUSSION: Increased NO production with the presence and the severity of inflammation supports the contribution of NO in the peri-implant inflammatory process. Loading is also likely to have an impact on NO metabolism, which suggests a role for NO in remodeling and adaptation of bone around dental implants. CONCLUSION: Besides the presence of inflammation, the severity of inflammation and loading also seem to have an impact on NO metabolism around dental implants.     

Evaluation of gingival crevicular fluid and peri‐implant sulcus fluid levels of periostin: A preliminary report

1 Background

Periostin is a protein present in alveolar bone and periodontal ligament whose function is related to response to external forces. The aims of this study are to detect levels of periostin in peri‐implant sulcular fluid (PISF) and gingival crevicular fluid (GCF) and to evaluate the relationship between periostin, pyridinoline cross‐linked carboxyterminal telopeptide of Type I collagen (ICTP), and C‐terminal cross‐linked telopeptide of Type I collagen (CTX) levels and clinical inflammatory symptoms and duration of functional loading.

2 Methods

The study population comprised nine women and four men with mean age 43.23 ± 12.48. Twenty “bone‐level designed” dental implants (DIs) placed in molar or premolar sites, without any signs of peri‐implant bone loss and with a restoration in function for at least 12 months, were included in the study with 20 contralateral natural teeth (NT) as controls. Clinical parameters and restoration dates of the implants were recorded. PISF, GCF, ICTP, CTX, and periostin levels were evaluated using enzyme‐linked immunosorbent assay.

3 Results

ICTP, CTX, and periostin levels were similar between DI and NT groups. There were no statistically significant differences between PISF and GCF values. When implants were grouped as healthy (gingival index [GI] = 0) and inflamed (GI ≥0), ICTP levels and PISF volume were lower in healthy implants compared with the inflamed group. Both periostin and CTX levels were negatively correlated with functioning time, suggesting less bone remodeling around DIs at later stages of functioning.

4 Conclusion

Findings of this study suggest collagen breakdown products may be used as markers to evaluate peri‐implant metabolism.     

Possible impact of inflammatory status on C‐telopeptide pyridinoline cross‐links of Type I collagen and osteocalcin levels around oral implants with peri‐implantitis: a controlled clinical trial

Summary Detection of progression level of peri‐implantitis may help in the prevention of oral implant failure. C‐telopeptide pyridinoline crosslinks of Type I collagen (ICTP) and osteocalcin (OC) are specific markers of bone turnover and bone degradation. Determination of the ICTP and OC levels in the peri‐implant sulcus fluid (PISF) may predict the metabolic and/or inflammatory changes in the peri‐implant bone. The aim of this clinical study was to evaluate ICTP and OC levels in the PISF for oral implants with and without peri‐implant bone destruction and correlate these levels with the traditional clinical peri‐implant parameters (probing depth, plaque index, gingival index and gingival bleeding time index) and radiographic bone level measurements. Fifteen patients with 30 peri‐implant sites with bone destruction (radiographic bone loss) and health were included. Clinical parameters were measured and PISF was collected from the sites. Peri‐implant sulcus fluid ICTP and OC levels were detected by radioimmunoassay technique from PISF samples. All clinical parameters demonstrated a significant increase in peri‐implantitis sites compared with healthy sites. The PISF volume of the peri‐implantitis sites was also significantly higher than of the healthy peri‐implant sites. Although not statistically significant, a trend of increase was demonstrated in ICTP PISF samples sampled from peri‐implantitis sites compared with healthy sites. A significant increase was noticed for OC PISF level in peri‐implantitis sites compared with healthy ones. As well as peri‐implant clinical measurements, volumetric changes at PISF may be counted as an important clinical parameter to distinguish the bone destruction sites from healthy sites around oral implants.     

Osmotic pressure of periimplant sulcular and gingival crevicular fluids: a split-mouth, randomized study of its measurement and clinical significance

Objectives: This study comparatively investigated periimplant sulcular fluid (PISF) and gingival crevicular fluid (GCF) by means of the osmotic pressure (OP) levels of PISF (PISFOP) and GCF (GCFOP). It was a preliminary research that aimed to quantify PISFOP and GCFOP as well as to evaluate their clinical significances around implants and teeth. Material and methods: Partially edentulous implant patients treated by the same clinicians and using the same implant system were randomized in a split‐mouth trial design. Fifty‐four implants and teeth from these patients were selected in the same mouth and jaw as matched pairs of samples, i.e. as symmetrical or corresponding implant and tooth. PISFOP/GCFOP measurement was performed by an osmometer following PISF/GCF sampling procedures. Clinical significance was evaluated by the correlations between PISFOP/GCFOP and some clinical examination parameters of periimplant/periodontal soft tissues. These parameters included Silness–Löe plaque index (PI), Löe–Silness gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD) and probing attachment level (PAL). Results: PISFOP was higher than GCFOP, and GI, BOP, PPD and PAL were higher in the implant group than in the tooth group (P<0.05). PISFOP positively correlated with the clinical parameters of implants (P<0.01 for PI, GI and BOP; P<0.05 for PPD and PAL), and GCFOP positively correlated with the clinical parameters of teeth (P<0.01 for PPD; P<0.05 for PI, GI, BOP and PAL). Conclusions: The results reveal that PISFOP and GCFOP may be measured by osmometer, and their levels may be related with the clinical conditions of periimplant/periodontal soft tissues. To cite this article:
Sakallιo?lu U, Lütfio?lu M, Sakallιo?lu EE, Sert S, Ceylan G. Osmotic pressure of periimplant sulcular and gingival crevicular fluids: a split‐mouth, randomized study of its measurement and clinical significance.
Clin. Oral Impl. Res. 22 , 2011; 706–710
doi: 10.1111/j.1600‐0501.2010.02044.x     

The evaluation of peri‐implant sulcus fluid osteocalcin,osteopontin, and osteonectin levels in peri‐implant diseases

1 Background

Peri‐implant mucositis is an inflammation of the soft tissues surrounding an implant. Peri‐implantitis refers to a process characterized by peri‐implant bone loss along with an inflammation of the soft tissues. Osteocalcin, osteopontin, and osteonectin proteins are related to bone remodeling. The aim of the present study was to investigate peri‐implant sulcus fluid (PISF) osteocalcin, osteopontin, and osteonectin levels in peri‐implant mucositis and peri‐implantitis.

2 Methods

Fifty‐two implants with peri‐implantitis, 46 implants with peri‐implant mucositis, and 47 control implants were included in the study. Clinical parameters including probing depth, modified sulcus bleeding index and modified plaque index were recorded. PISF osteocalcin, osteopontin, and osteonectin levels were analyzed by ELISA kits.

3 Results

There were no significant differences in PISF osteocalcin, osteopontin, and osteonectin total amounts between healthy controls, peri‐implant mucositis and peri‐implantitis groups (P > 0.05). Probing depths were not correlated with PISF osteocalcin, osteopontin, and osteonectin levels in the study groups (P > 0.05).

4 Conclusions

Soft tissue inflammation around dental implants does not cause a change in osteocalcin, osteopontin, and osteonectin levels in PISF. Also, peri‐implantitis does not seem to give rise to an increase in PISF levels of osteocalcin, osteopontin, and osteonectin.     

Nitric oxide and arginase levels in peri-implant tissues after delayed loading

ObjectiveNitric oxide (NO) is synthesized from the conversion of L-arginine to L-citrulline by NO synthase (NOS). Arginase can compete with NOS for the common substrate L-arginine, and thus inhibit NO production. NO levels and arginase ezyme might affect the bone remodeling cycle around implants. The aim of this studywas to investigate NO and arginase levels in gingival crevicular fluid (GCF), peri-implant sulcular fluid (PISF), and saliva.Materials and methodsTwenty patients with one or more implants (Straumann^®; Institute Straumann AG, Basel, Switzerland) restored with fixed crown prostheses were included in the study. Plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing (BOP) were recorded from six sites of each tooth and implant at baseline and at months 1, 3, and 6 after loading. The saliva, GCF, and PISF were collected at baseline and at months 1, 3, and 6 after loading. NO level and arginase enzyme were evaluated in GCF, PISF, and saliva.ResultsArginase and NO levels in saliva did not change significantly from baseline to months 1, 3, and 6. However, both PISF NO and arginase levels showed an increased pattern from baseline to month 6. NO levels were significantly higher at months 3 and 6, compared to baseline, while PISF arginase levels increased significantly from baseline to months 3 and 6.ConclusionNO and arginase enzyme measurements in saliva, GCF, and PISF may be beneficial in the determination of current peri-implant tissues. In particular, PISF might provide more information than saliva.     

种植体周围龈沟液中酶水平的研究

目的 初步探讨种植体修复后第１年内龈沟液（ｇｉｎｇｉｖａｌ ｃｒｅｖｉｃｕｌａｒ ｆｌｕｉｄ,ＧＣＦ）量及其中的天冬氨酸转氨酸（ａｓｐａｒｔａｔｅ ａｍｉｎｏｔｒａｎｓｆｅｒａｓｅ,ＡＳＴ）和碱性磷酸酶（ａｌｋａｌｉｎｅ ｐｈｏｓｐｈａｔａｓｅ,ＡＬＰ）水平的变化,及其与种植体周围为症及骨丧失的关系。方法 以基台连接术后１～１．５个月为基线,修复后３、６、１２个月时分别对１２例患者２６个Ｂｒａｎｅ     

TNF-alpha TGF-beta2 and IL-1beta levels in gingival and peri-implant crevicular fluid before and after de novo plaque accumulation

Aims: The aim of this split‐mouth study was to investigate levels of tumour necrosis factor alpha (TNF‐α), transforming growth factor beta (TGF‐β2) and interleukin‐1 beta (IL‐1β) in gingival crevicular fluid (GCF) and peri‐implant crevicular fluid (PICF) after a 21‐day‐period of de novo plaque accumulation in the same patient. Material and Methods: In 25 patients, samples of GCF and PICF were collected in the sulcus of the tooth and of the implant after professional hygiene. After the no‐hygiene phase (21 days), second samples of GCF and PICF were taken. Third samples were collected after 69 days of re‐establishment oral hygiene techniques. The crevicular fluids were used to determine the volume and the levels of TNF‐α, TGF‐β2 and IL‐1β. Results: The volume of the crevicular fluids increased significantly after 21 days of plaque accumulation around teeth and implants and decreased significantly by 69 days. TNF‐α and TGF‐β2 did not change significantly among the three different samples. A significant increase of IL‐1β was observed after plaque accumulation around the teeth GCF, whereas in the PICF the increase was not statistically significant. Conclusions: These data suggest that increased volumes of GCF and PICF could be useful markers of early inflammation in gingival and peri‐implant tissues. In the presence of de novo plaque, implants showed lower, and nearly significant, levels of IL‐1β compared with teeth.     

Tenascin-C and matrix metalloproteinase-9 levels in crevicular fluid of teeth and implants

Background: The role of and interaction between bacterial infection and biomechanical impact in the development of peri‐implant inflammatory processes is not clear. Objective: To determine the amount and concentration of tenascin‐C (TNC) in gingival crevicular fluid (GCF) around teeth and in peri‐implant sulcus fluid from healthy implants and implants with peri‐implantitis, and to correlate it with matrix metalloproteinase‐9 (MMP‐9) levels. Materials and Methods: Seven control individuals and 18 patients with 41 implants with/without peri‐implantitis were included. GCF was collected with filter strips and volumes were measured with a Periotron device. The amount of serum albumin per sample was quantified by densitometric analysis of Coomassie‐stained sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Relative activity of MMP‐9 was determined from the densitometry of zymograms. Amounts and concentrations of TNC were evaluated by ELISA. Results: Relative MMP‐9 activity was increased in peri‐implantitis. A tendency was observed to measure higher TNC concentrations at teeth than at implants. The amount of TNC in GCF collected from healthy implant sites and the peri‐implantitis sites was significantly different. Based on immunoblotting, TNC in GCF seemed degraded. In contrast to TNC, MMP‐9 was significantly related to the PD and the volume of GCF. Conclusion: TNC is known to be induced in inflammation. The increase found in peri‐implantitis was less than expected. In the context of peri‐implantitis, TNC might be a marker of bone remodelling rather than inflammation and infection. A possible proteolytic degradation of TNC during peri‐implantitis needs to be studied.     

The Profile of Inflammatory Cytokines in Gingival Crevicular Fluid around Healthy Osseointegrated Implants

Objective: Regardless of gingival health and subgingival microbiology, production of cytokines within peri‐implant tissues may be different from that of teeth. The objective of this study was to describe the peri‐implant levels of pro‐inflammatory cytokines and subgingival microbiology in clinically healthy sites. Materials and Methods: Subgingival plaque and gingival crevicular fluid (GCF) were obtained from 28 clinically healthy implants and 26 teeth selected from 24 individuals. Microbial composition was determined by selective anaerobic culture techniques. Pro‐inflammatory cytokines were quantified by flow cytometry analysis of GCF. The concentration of cytokines between implants and teeth were compared with the independent t‐test. Results: The concentration of cytokines was higher in GCF from healthy implants than in teeth. The profile of cytokines was characteristic of an innate immune response. A more frequent detection of periodontopathic bacteria was observed in teeth than implants. Cultivable levels of periodontopathic bacteria were similar between implants and teeth. Conclusions: Despite gingival tissue health and scarce plaque accumulation, the profile of inflammatory cytokines in implant crevicular fluid was distinctive of an innate immune response and in higher concentration than in teeth. Other than bacterial stimulus, intrinsic factors related to implants may account for more cytokine production than teeth.     

The effect of delayed versus early loading on nitric oxide metabolism around dental implants: an 18-month comparative follow-up study

PURPOSE: Nitrite is a stable end-product of nitric oxide oxidation. The aim of the present study was to quantitatively analyze peri-implant sulcular fluid (PISF) nitrite levels in a longitudinal study design to evaluate the potential changes in nitric oxide metabolism in relation to the clinical status of the peri-implant site and the loading style of the dental implants. MATERIALS AND METHODS: A total of 34 implants, either early loaded (EL) or delayed loaded (DL), in 17 patients were followed up for a period of 18 months. Clinical parameters were recorded, PISF samples were obtained, and PISF nitrite levels were spectrophotometrically determined. Clinical measurements and nitrite analysis were repeated at 1, 3, 6, 9, 12, and 18 months. RESULTS: Despite the gradual decrease in clinical parameters, fluctuations in PISF total nitrite levels were observed during follow-up. The pattern of nitric oxide metabolism, as reflected by PISF nitrite levels, also demonstrated differences between EL and DL implants that diminished toward the end of the experimental period. DISCUSSION: Although the presence of clinical and subclinical gingival inflammation contributes to the PISF total nitrite levels, nitric oxide metabolism is also associated with healing and bone remodeling, and the pattern of loading seemed to have an impact on nitric oxide production at dental implant sites. CONCLUSION: Nitric oxide production at dental implant sites seems to be tightly regulated to enable the maintenance of peri-implant bone.     

Reversibility of experimental peri-implant mucositis compared with experimental gingivitis in humans

Objective: To monitor clinical, microbiological and host‐derived alterations occurring around teeth and titanium implants during the development of experimental gingivitis/mucositis and their respective healing sequence in humans. Material and methods: Fifteen subjects with healthy or treated periodontal conditions and restored with dental implants underwent an experimental 3‐week period of undisturbed plaque accumulation in the mandible. Subsequently, a 3‐week period with optimal plaque control was instituted. At Days 0, 7, 14, 21, 28, 35 and 42, the presence/absence of plaque deposits around teeth and implants was assessed, (plaque index [PlI]) and the gingival/mucosal conditions were evaluated (gingival index[GI]). Subgingival/submucosal plaque samples and gingival/mucosal crevicular fluid (CF) samples were collected from two pre‐determined sites around each experimental unit. CF samples were analyzed for matrix‐metalloproteinase‐8 (MMP‐8) and interleukin‐1beta (IL‐1β). Microbial samples were analyzed using DNA–DNA hybridization for 40 species. Results: During 3 weeks of plaque accumulation, the median PlI and GI increased significantly at implants and teeth. Implant sites yielded a greater increase in the median GI compared with tooth sites. Over the 6‐week experimental period, the CF levels of MMP‐8 were statistically significantly higher at implants compared with teeth (P<0.05). The CF IL‐1β levels did not differ statistically significantly between teeth and implants (P>0.05). No differences in the total DNA counts between implant and tooth sites were found at any time points. No differences in the detection frequency were found for putative periodontal pathogens between implant and tooth sites. Conclusion: Peri‐implant soft tissues developed a stronger inflammatory response to experimental plaque accumulation when compared with that of their gingival counterparts. Experimental gingivitis and peri‐implant mucositis were reversible at the biomarker level. Clinically, however, 3 weeks of resumed plaque control did not yield pre‐experimental levels of gingival and peri‐implant mucosal health indicating that longer healing periods are needed. To cite this article:
Salvi GE, Aglietta M, Eick S, Sculean A, Lang NP & Ramseier CA. Reversibility of experimental peri‐implant mucositis compared with experimental gingivitis in humans.
Clin. Oral Impl. Res. 23 , 2012; 182–190.
doi: 10.1111/j.1600‐0501.2011.02220.x     

Longitudinal Comparison of Cytokines in Peri‐Implant Fluid and Gingival Crevicular Fluid in Healthy Mouths

Background: Peri‐implant and gingival tissues provide important sealing and protective functions around implants and teeth, but comparisons of the immunologic responses of these tissues after implant placement have not been conducted. Cytokine levels were measured in peri‐implant crevicular fluid (PICF) and gingival crevicular fluid (GCF) as surrogate measures of immune function at subcrestally placed dental implants and healthy periodontal sites during a 1‐year monitoring period. Methods: A total of 27 dental implants were placed subcrestally in 21 periodontally healthy patients (mean age: 49.0 ± 13.4 years). Repeated clinical and cytokine measurements were obtained over 12 months. GCF and PICF samples were collected and analyzed by cytokine microarray. Data were examined by non‐parametric analysis of variance. Results: Plaque and bleeding indices were similar among all patients (P >0.05) at baseline. During 1 year of monitoring, the mean volumes of PICF and GCF were similar (P >0.05). The levels of interleukin (IL)‐4, ‐6, ‐10, and ‐12p70, tumor necrosis factor‐α, and interferon‐γ in GCF and PICF were not significantly different and did not vary over time (P >0.05). The levels of IL‐1α were higher in GCF than PICF at 1, 2, 6, and 12 months, as were the levels of IL‐8 at 1, 2, 4, 6, and 12 months (P <0.001). Transforming growth factor‐β1 in PICF and GCF exhibited time‐dependent increases, and vascular endothelial growth factor was reduced at 1 year without differences between PICF and GCF (P >0.05). Conclusion: Within the limitations of this study design, it can be concluded that after subcrestal implant placement, the immune response of peri‐implant and periodontal tissues, as assessed by cytokine levels in PICF and GCF, is similar.     

In vivo expression of proteases and protease inhibitor,a serpin,by periodontal pathogens at teeth and implants

Porphyromonas gingivalis and Tannerella forsythia secrete proteases, gingipains and KLIKK‐proteases. In addition, T. forsythia produces a serpin (miropin) with broad inhibitory spectrum. The aim of this pilot study was to determine the level of expression of miropin and individual proteases in vivo in periodontal and peri‐implant health and disease conditions. Biofilm and gingival crevicular fluid (GCF)/ peri‐implant sulcular fluid (PISF) samples were taken from healthy tooth and implant sites (n = 10), gingivitis and mucositis sites (n = 12), and periodontitis and peri‐implantitis sites (n = 10). Concentration of interleukin‐8 (IL‐8), IL‐1β and IL‐10 in GCF was determined by enzyme‐linked immunosorbent assay. Loads of P. gingivalis and T. forsythia and the presence of proteases and miropin genes were assessed in biofilm by quantitative PCR, whereas gene expression was estimated by quantitative RT‐PCR. The presence of P. gingivalis and T. forsythia, as well as the level of IL‐8 and IL‐1β, were associated with disease severity in the periodontal and peri‐implant tissues. In biofilm samples harboring T. forsythia, genes encoding proteases were found to be present at 72.4% for karilysin and 100% for other KLIKK‐protease genes and miropin. At the same time, detectable mRNA expression of individual genes ranged from 20.7% to 58.6% of samples (for forsylisin and miropsin‐1, respectively). In comparison with the T. forsythia proteases, miropin and the gingipains were highly expressed. The level of expression of gingipains was associated with those of miropin and certain T. forsythia proteases around teeth but not implants. Cumulatively, KLIKK‐proteases and especially miropin, might play a role in pathogenesis of both periodontal and peri‐implant diseases.     

Correlation of peri-implant health and myeloperoxidase levels: a cross-sectional clinical study

OBJECTIVES: At present, there are no diagnostic tools that permit early detection of peri-implantitis. The purpose of this cross-sectional study was to evaluate the correlation of myeloperoxidase (MPO) levels with traditional periodontal clinical parameters around dental implants including peri-implant pocket probing depth (PPD), gingival index (GI) and bleeding on probing (BOP), since MPO has been associated with destruction of periodontal tissues. MATERIAL AND METHODS: Twenty-four healthy adult volunteers (9 men and 15 women) with 64 Ankylos Biofunctional implants (DentsplyFriadent, Mannheim, Germany) were recruited from Tallinn Dental Clinic. Biochemical and clinical parameters evaluated were the following ones: the level of MPO in the peri-implant sulcus fluid (PISF) (an analog for gingival crevicular fluid in natural teeth), PPD (mm), GI (0,1,2 or 3), and BOP (0 or 1). RESULTS AND CONCLUSION: In comparison to the clinically healthy implants, total amounts of MPO were significantly higher in PISF collected around implants with inflammatory lesions. In addition, the levels of MPO 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 MPO could be promising marker of inflammation around dental implants.     

Comparison of bacterial plaque samples from titanium implant and tooth surfaces by different methods

Studies have shown similarities in the microflora between titanium implants or tooth sites when samples are taken by gingival crevicular fluid (GCF) sampling methods. The purpose of the present study was to study the microflora from curette and GCF samples using the checkerboard DNA-DNA hybridization method to assess the microflora of patients who had at least one oral osseo-integrated implant and who were otherwise dentate. Plaque samples were taken from tooth/implant surfaces and from sulcular gingival surfaces with curettes, and from gingival fluid using filter papers. A total of 28 subjects (11 females) were enrolled in the study. The mean age of the subjects was 64.1 years (SD+/-4.7). On average, the implants studied had been in function for 3.7 years (SD+/-2.9). The proportion of Streptococcus oralis (P<0.02) and Fusobacterium periodonticum (P<0.02) was significantly higher at tooth sites (curette samples). The GCF samples yielded higher proportions for 28/40 species studies (P-values varying between 0.05 and 0.001). The proportions of Tannerella forsythia (T. forsythensis), and Treponema denticola were both higher in GCF samples (P<0.02 and P<0.05, respectively) than in curette samples (implant sites). The microbial composition in gingival fluid from samples taken at implant sites differed partly from that of curette samples taken from implant surfaces or from sulcular soft tissues, providing higher counts for most bacteria studied at implant surfaces, but with the exception of Porphyromonas gingivalis. A combination of GCF and curette sampling methods might be the most representative sample method.     

Acute‐phase proteins and immunoglobulin G against Porphyromonas gingivalis in peri‐implant crevicular fluid: a comparison with gingival crevicular fluid

This investigation had 2 aims: 1) to determine the levels of acute‐phase proteins and immunoglobulin G (IgG) against Porphyromonas gingivalis in peri‐implant crevicular fluid (PICF) and their association with the clinical condition of the peri‐implant mucosa; and 2) to compare the inflammatory and immunological responses at implants and teeth as reflected by the gingival crevicular fluid (GCF) and PICF levels of acute‐phase proteins and immunoglobulins. Thirty‐one partially edentulous subjects were recruited for this study. PICF was sampled from 1 healthy and 1 inflamed site from each patient; GCF was sampled from an additional 21 healthy and 27 inflamed tooth sites of the same patients. GCF and PICF were collected with paper strips (for 30 s) and analysed using enzyme‐linked immunosorbent assays for α2‐macroglobulin, α1‐antitrypsin, transferrin, lactoferrin and IgG against P. gingivalis . This investigation demonstrated that the absolute amounts of the acute‐phase proteins and IgG against P. gingivalis are higher in GCF and PICF from inflamed than healthy sites. No significant differences were observed between PICF and GCF components at either healthy or inflamed sites, suggesting that inflammatory and immune events are similar in the peri‐implant mucosa and gingiva in humans and that PICF and GCF production is governed by similar mechanisms.