Detection of implant crevicular fluid prostaglandin E2 levels for the assessment of peri-implant health: a pilot study

Inflammatory changes in the peri-implant tissues may lead to peri-implantitis and bone loss. Prostaglandin E2 has been shown to have proinflammatory effects on peri-implant tissues, including mediation of bone resorption. The aim of this study was to assess prostaglandin E2 levels in implant crevicular fluid and the possibility of using this method in diagnosing peri-implant mucositis. Twenty-four dental implants with 3 mm or greater probing depths comprised the test group and another 24 implants with probing depths less than 3 mm served as the control group. Plaque index (PI), gingival index (GI), and probing pocket depths (PPD) were recorded. Implant crevicular fluid was obtained by collection onto periopapers. Then, prostaglandin E2 levels were evaluated using a commercially available enzyme immuno-assay kit. PI, GI, PPD, and implant crevicular fluid (ICF) levels of prostaglandin E2 were found to be statistically significantly higher in the test group (P < 0.05). In the test group, gingival index and probing depths were found to be statistically significantly related with ICF prostaglandin E2 levels (P < 0.05). In the control group, there was no statistically significant positive correlation between clinical parameters and ICF prostaglandin E2 levels (P > 0.05). It may be speculated that biochemical tests, such as the detection of prostaglandin E2 levels in the crevicular fluid are useful diagnostic methods for the maintenance of functional dental implants.     

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.     

Calprotectin and cross-linked N-terminal telopeptides in peri-implant and gingival crevicular fluid

In a previous study on guided bone augmentation, a new collagen membrane was compared with an e-PTFE one on 28 partially edentulous patients who received 50 dental implants at stage 2 surgery. After implant integration and subsequent loading, we were able to recruit 22 patients with 22 implants and their contra-lateral corresponding teeth for longitudinal observation. Clinical parameters probing depth (PD), bleeding on probing (BoP), plaque index (PI), assessment of gingival crevicular fluid (GCF) and peri-implant crevicular fluid (PCF) volumes and periapical radiographs were performed at 2- and 3-year control appointments. Calprotectin (MRP 8/14) and cross-linked N-terminal telopeptide (NTx) levels in both crevicular fluids were determined by ELISA. PD was significantly reduced from years 2 to 3 appointments at implant sites as at teeth sites. At the 3-year appointment in both compartments, fluid volumes were significantly increased, which corresponded well with ascending NTx levels. The total amount of calprotectin decreased non-significantly in both GCF and PCF samples. Periapical radiographs revealed stable bone conditions around implants without significant changes from years 2 to 3 examinations. Clinical peri-implant parameters were considered as stable as the periodontal parameters of their corresponding teeth. A parallel increase in NTx levels in both GCF and PCF at 3-year appointment is not clearly understood; it may reflect an upregulation in the overall bone turnover rate.     

C-telopeptide pyridinoline cross-links (ICTP) and periodontal pathogens associated with endosseous oral implants.

Detection of periodontal or peri-implant sites exhibiting progressing disease or those at risk of deterioration has proven difficult. Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), a marker specific for bone degradation found in gingival crevicular fluid (GCF), has been associated with both bone and attachment loss in periodontitis and may be useful for predicting disease activity. The aim of this cross-sectional study was to examine the relationship between ICTP levels and subgingival species around implants and teeth from 20 partially and 2 fully edentulous patients. GCF and plaque samples were collected from the mesiobuccal site of each implant and tooth. Radioimmunoassay techniques were utilized to determine GCF ICTP levels. Plaque samples were analyzed utilizing checkerboard DNA-DNA hybridization. Traditional clinical parameters were assessed. Seventy-one implants and 370 teeth from 22 subjects were examined. ICTP levels and subgingival plaque composition were not significantly different between implants and teeth. Implant sites colonized by Prevotella intermedia, Capnocytophaga gingivalis, Fusobacterium nucleatum ss vincentii, and Streptococcus gordonii exhibited odds ratios of 12.4, 9.3, 8.1, and 6.7, respectively of detecting ICTP. These results suggest a relationship between elevated ICTP levels at implant sites and some species associated with disease progression. Longitudinal studies are necessary to determine whether elevated ICTP levels may predict the development of peri-implant bone loss.     

Interleukin-1β and Interleukin-6 Expression and Gene Polymorphisms in Subjects with Peri-Implant Disease

Background: Polymorphisms found in the IL-1 family genes have been associated with susceptibility of periodontal disease. However, very little is known about the relationship between polymorphisms on inflammatory mediators' genes and peri-implant disease. Purpose: The aim of the present study was to evaluate interleukin-1β (IL-1β) and interleukin-6 (IL-6) concentration in the crevicular fluid, and the impact of gene polymorphisms on healthy and diseased implants in comparison with healthy teeth. Materials and Methods: We examined 47 implants and teeth in 47 patients grouped as: 31 healthy implants, 16 implants with peri-implantitis, 31 healthy teeth from patients with healthy implants, and 16 healthy teeth from patients with peri-implantitis. Clinical parameters were recorded from all implants and teeth. Gingival crevicular fluid was collected to evaluate the concentration of IL-1β and IL-6. Cells from buccal mucosa were collected and their genomic DNA extracted for identification of the following polymorphisms: IL1B+3954, IL1B-511, and IL6-174. Results: Clinical evaluation demonstrated that implants with peri-implantitis had less favorable indexes for probing depth (PD), relative clinical attachment level (CAL), bleeding on probing, and suppuration when compared with healthy implants and, for PD and CAL when compared with healthy teeth. There was no significant difference in the concentration of IL-1β and IL-6 detected between groups. There were no statistically significant differences between alleles and polymorphisms distribution on the studied population. Conclusions: There was no correlation between the concentration of IL-1β and IL-6 in the crevicular sulcular fluid present in healthy or diseased osseointegrated implants in comparison with healthy teeth. The studied gene polymorphisms had no influence on peri-implant disease.     

Clinical and radiographic evaluation of periodontal and peri-implant conditions in patients with implant-supported prosthesis

The aim of the present study was to clinically and radiographically assess the peri-implant and periodontal conditions in partially edentulous patients with implant-supported fixtures installed, at least, one year prior to the study. 41 patients were examined by a calibrated examiner in relation to the following implant-associated parameters: Modified Plaque Index (mPlI), Modified Bleeding Index (mBI), probing depth (PD), clinical attachment level (CAL) and bleeding on probing of the bottom of the crevice (BOP). Also, the remaining teeth were assessed in terms of Plaque Index (PlI), Gingival Index (GI), PD, CAL and BOP. The peri-implant bone loss was evaluated by means of periapical radiographs. Measurements of pre-operatory and final bone levels allowed an estimation of bone loss associated to teeth and a comparison with bone loss around implants. None of the individuals presented late loss of implants until the examination took place. No statistically significant differences were observed between PlI (0.90+/-0.07) and mPlI (0.82+/-0.13), or between GI (0.11+/-0.02) and mBI (0.10+/-0.02). However, PD, CAL and BOP values were higher in implants than in teeth (Wald Test, p<0.01). Implants presented a mean annual bone loss during the study period of 0.77 mm (SE=0.06). Teeth virtually did not present any bone loss (mean value of 0.36%) whereas implants exhibited a bone loss value of 17.11%. Plaque accumulation and marginal inflammation did not differ between teeth and implants. However, subgingival inflammation was higher in implants than in teeth. The destruction measurements suggest greater losses in implants, as expected because of tissue remodelation.     

Association between periodontal and peri-implant conditions: a 10-year prospective study

OBJECTIVES: The aims of this study were to (1) compare prospectively the clinical and radiographic changes in periodontal and peri-implant conditions, (2) investigate the association of changes in periodontal parameters and peri-implant conditions over a mean observation period of 10 years (8-12 years) after implant installation, and (3) evaluate patient risk factors known to aggravate the periodontal conditions for their potential influence on the peri-implant tissue status. MATERIALS AND METHODS: Eighty-nine partially edentulous patients with a mean age of 58.9 years (28-88 years) were examined at 1 and 10 years after implant placement. The patients contributed with 179 implants that were placed after comprehensive periodontal treatment and restored with crowns or fixed partial dentures. One hundred and seventy-nine matching control teeth were chosen as controls. Also, the remaining teeth (n=1770) in the dentitions were evaluated. Data on smoking habits and general health aspects were collected at 1 and 10 years as well. RESULTS: At 10 years, statistically significant differences existed between implants and matching control teeth with regard to most of the clinical and radiographic parameters (P<0.01) with the exception of plaque index (PII) and recession. Multiple regression analyses were performed to associate combinations of periodontal diagnostic parameters to the peri-implant conditions: probing attachment level (PAL) at implants at 10 years was associated with implant location, full-mouth probing pocket depth (PPD) and full-mouth PAL (P=0.0001, r2=0.36). PPD at implants at 10 years correlated to implant location, full-mouth PPD and full-mouth PAL (P<0.001, r2=0.47). Marginal bone level at implants at 10 years was significantly associated to smoking, general health condition, implant location, full-mouth PAL and change over time in full-mouth PPD (P<0.001, r2=0.39). CONCLUSIONS: These results present evidence for the association between periodontal and peri-implant conditions and the changes in these tissues over 10 years in partially edentulous patients.     

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.     

Osteocalcin,deoxypyridinoline and interleukin-1beta in peri-implant crevicular fluid of patients with peri-implantitis

The aim of the present study was to analyze the levels of osteocalcin, deoxypyridinoline (Dpd) and interleukin-1beta as markers of bone metabolism in peri-implant crevicular fluid (PICF) from peri-implantitis patients. PICF was sampled from a total of 34 endosseous titanium implants from 16 patients; nine females (mean age 52.8, range 40-62 years) and seven males (mean age 56.0, range 36-66 years). The implants had been in place for a period of 9-112 months (mean; 35.8 months) since the loading. These sites were categorized as six peri-implantitis, eight peri-implant mucositis and 20 healthy implant. PICF volume from peri-implantitis sites was significantly higher than mucositis and healthy implant sites (P < 0.01). Osteocalcin levels in PICF from mucositis sites were significantly higher than healthy implants (P < 0.05), whereas peri-implantitis sites were not significantly different from either mucositis or healthy implant sites. Dpd could not be detected in any of the samples examined. IL-1beta levels in PICF from peri-implantitis sites were significantly higher than levels from peri-implant mucositis (P < 0.05) and healthy implant sites (P < 0.01). In conclusion, osteocalcin in PICF may reflect increased local bone turnover around implants. Further, IL-1beta should be a useful marker for peri-implant inflammation.     

Longitudinal evaluation of aspartate aminotransferase in the crevicular fluid of implants with bone loss and signs of progressive disease.

Aspartate aminotransferase (AST) has been shown to be a promising host marker for periodontal disease progression. The aim of the present study was to analyze AST in the crevicular fluid (CF) of implants exhibiting peri-implantitis and to evaluate the association between AST levels and progressive attachment loss. Twenty patients who had received a total of 42 endosseous cylindric titanium implants were examined. Radiographic assessment of preexisting bone loss and clinical measurements, including electronic attachment of probing, presence or absence of plaque, bleeding on probing, and AST analysis in CF, were performed on 2 occasions 6 months apart. During this study period 13 of 168 sites in 7 patients experienced further loss of attachment greater than or equal to 1.0 mm (median 1.7 mm; interquartile range 0.4 mm). Evaluation of a positive AST test (> or = 300 microIU) in site-specific diagnosis revealed low positive (8%) and high negative predictive values (92%), with a sensitivity of 15% and a specificity of 83%. These results indicate that, in contrast to periodontal disease, the assessment of AST in peri-implant crevicular fluid may be of limited value as a diagnostic and prognostic marker for peri-implant disease.     

Relation between smoking and biomarkers of bone resorption associated with dental endosseous implants

The aim of this study was to determine the effects of smoking on pyridinoline concentrations in crevicular fluid collected from around dental implants. Samples of crevicular fluid were collected from 4 sites around each implant and tooth, if present, for a group of 16 patients using methylcellulose strips. Samples were collected from 104 implants and 49 teeth. Eight of the 16 patients were current smokers. Crevicular fluid samples were eluted from methylcellulose strips using phosphate-buffered saline containing 0.1% bovine serum albumin and centrifugation. Pyridinoline was quantified using a competitive enzyme immunoassay. Results showed that there were statistically insignificant differences between the amounts of pyridinoline (mean +/- standard deviation [SD]) around teeth of nonsmokers versus smokers (0.011 +/- 0.003 and 0.014 +/- 0.006 nmol/L, respectively). However, the mean (+/- SD) pyridinoline levels around the implants of nonsmokers (0.012 +/- 0.018 nmol/L) were significantly (P <0.01) less than that of smokers (0.030 +/- 0.006 nmol/L). These results demonstrate that pyridinoline levels are specifically elevated in the crevicular fluid associated with endosseous dental implants of smokers and suggest that smoking may affect implant success in part through alterations in the levels of bone resorption.     

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.     

Analysis of early biofilm formation on oral implants in man

Biofilm formation on oral implants can cause inflammation of peri-implant tissues, which endangers the long-term success of osseointegrated implants. It has been reported previously that implants revealing signs of peri-implantitis contain subgingival microbiota similar to those of natural teeth with periodontitis. The purpose of the first part of this study was an atraumatic, quantitative investigation of biofilm formation on oral implant abutments; the objective of the second part was to investigate whether Haemophilus actinomycetemcomitans and Porphyromonas gingivalis were present in the crevicular fluid around oral implants. Biofilm formation on 14 healing abutments, inserted for 14 days in 10 patients, was analysed quantitatively by use of secondary-electron and Rutherford-backscattering-detection methods. A 16S rRNA-based polymerase chain reaction detection method was used to detect the presence of H. actinomycetemcomitans and P. gingivalis in the crevicular fluid. For this investigation, samples of sulcus fluid were collected with sterile paper points at four measurement points per abutment. The difference between biofilm coverage of supragingival surfaces (17.5 +/- 18.3%) and subgingival surfaces (0.8 +/- 1.0%) was statistically significant (P < 0.05). By use of universal primers, bacteria were found in all the samples taken, although the two periodontal pathogens were not found in any of the samples. The absence of periodontal pathogens from the sulcus fluid during initial bacterial colonization, despite massive supragingival biofilm formation, substantiates the assumption that cellular adherence of peri-implant tissue by means of hemidesmosoma, actin filaments and microvilli reduces the risk of formation of anaerobic subgingival pockets.     

Microbiota and crevicular fluid collagenase activity in the osseointegrated dental implant sulcus: A comparison of sites in edentulous and partially edentulous patients

The soft tissues adjacent to osseointegrated dental implants (OII) were investigated using clinical, biochemical and microbiological methods. Tooth and implant crevices were compared in 15 partially edentulous patients, examining 28 peri-implant and 19 periodontal sites, and in 6 edentulous patients, examining 13 implant sites. Sites were classified by standard periodontal indices; the crevicular fluid flow determined; crevicular fluid was collected for collagenase assays; and the subgingival bacterial flora was examined and cultured. Differences in clinical parameters were noted in that implants had significantly less keratinized gingiva and deeper probing depths. Crevicular fluid was present in the OII sulcus but the crevicular fluid flow did not differ from that observed from tooth sites either in the partially edentulous or edentulous patients. Tissue collagenase activity and collagenase inhibitor were detected in the implant crevicular fluid and, as in periodontal sites, a strong inverse relationship was found between the levels of active collagenase and collagenase inhibitor. Microbiology included darkfield microscopy, anaerobic culturing for total colony forming unit counts and identification of black pigmented Bacteroides (BPB). Few differences were observed between implants and teeth in partially edentulous patients, indicating that crevices around teeth may act as reservoirs of bacteria which can colonize implant sites. A higher percentage of BPBs and wet spreaders (Capnocytophaga) was noted at partially edentulous implant sites when compared with edentulous implant sites, perhaps reflecting the lower numbers of periodontal pathogens present in edentulous mouths. Overall, the characteristics of implant sulci appear to be similar to periodontal sulci with respect to crevicular fluid flow and microflora.     

Bleeding on probing and pocket probing depth in relation to probing pressure and mucosal health around oral implants

Objectives: To assess the bleeding on probing (BOP) tendency and periodontal probe penetration when applying various probing forces at implant sites in patients with a high standard of oral hygiene with well-maintained peri-implant tissues.
Material and methods: Seventeen healthy patients with excellent oral hygiene in a maintenance program after having been treated for periodontitis or gingivitis were recruited. Missing teeth had been replaced using oral implants. The BOP and probing depth (PPD) were assessed at the mid-buccal, mid-oral, mesial and distal aspects of the buccal surfaces of each implant. Moreover, contralateral teeth were designated and assessed for BOP and PPD in the same locations and at the same observation visits. At each visit, implants and contralateral teeth were randomly assigned to one of the standardized probing forces (0.15 or 0.25 N). The second probing force was applied at the repetition of the examination 7 days later.
Results: Increasing the probing pressure by 0.1 N from 0.15 N resulted in an increase of BOP percentage by 13.7% and 6.6% for implants and contralateral teeth, respectively. There appeared to be a significant difference of the mean BOP percentage at implant and tooth sites when a probing pressure of 0.25 N was applied. A significantly deeper mean PPD at implant sites compared with tooth sites was found irrespective of the probing pressure applied.
Conclusions: The results of the present study demonstrated that 0.15 N might represent the threshold pressure to be applied to avoid false positive BOP readings around oral implants. Hence, probing around implants demonstrated a higher sensitivity compared with probing around teeth.     

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.     

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     

Peri-implant diseases: diagnosis and risk indicators

Background: Peri-implant diseases include peri-implant mucositis, describing an inflammatory lesion of the peri-implant mucosa, and peri-implantitis, which also includes loss of supporting bone.
Methods: A literature search of the Medline database (Ovid), up to 21 January 2008 was carried out using a systematic approach, in order to review the evidence for diagnosis and the risk indicators for peri-implant diseases.
Results: Experimental and clinical studies have identified various diagnostic criteria including probing parameters, radiographic assessment and peri-implant crevicular fluid and saliva analyses. Cross-sectional analyses have investigated potential risk indicators for peri-implant disease including poor oral hygiene, smoking, history of periodontitis, diabetes, genetic traits, alcohol consumption and implant surface. There is evidence that probing using a light force (0.25 N) does not damage the peri-implant tissues and that bleeding on probing (BOP) indicates presence of inflammation in the peri-implant mucosa. The probing depth, the presence of BOP, and suppuration should be assessed regularly for the diagnosis of peri-implant diseases. Radiographs are required to evaluate supporting bone levels around implants. The review identified strong evidence that poor oral hygiene, a history of periodontitis and cigarette smoking, are risk indicators for peri-implant disease. Future prospective studies are required to confirm these factors as true risk factors.     

Cathepsin K levels in the crevicular fluid of dental implants: a pilot study

OBJECTIVE: To determine the concentration of cathepsin K secreted into the crevicular fluid around dental implants and its correlation with clinical parameters of healthy implants and implants showing clinical signs of peri-implantitis. MATERIAL AND METHODS: Nineteen patients with 40 implants with and without peri-implantitis were enrolled in the study. Peri-implantitis was diagnosed by the pocket probing depth (PD), the modified bleeding index (MBI), the modified plaque index (MPI) and by radiographic signs of bone loss. Gingival crevicular fluid collected from the buccal and lingual sites was adsorbed to filter strips. Cathepsin K levels and total protein within the crevicular fluid were determined by immunoassay and the bicinchoninic method, respectively. RESULTS: Cathepsin K per filter strip normalized to the time of collection was 10.1 (0-33.5) pmol/sample around control implants and 22.4 (3.7-56.3) pmol/sample in the peri-implantitis group. The difference between the medians was significant (p < 0.01). Absolute cathepsin K levels in the crevicular fluid of all implants investigated showed a positive correlation with PD (R = 0.25; p = 0.03), MPI (R = 0.28; p = 0.01) and MBI (R = 0.32; p < 0.01). Absolute cathepsin K levels in the crevicular fluid also correlated with the adsorbed volume of gingival crevicular fluid (R = 0.51; p < 0.01). When normalized to the adsorbed volume of gingival crevicular fluid, the concentration of cathepsin K was 2.2 (0.01-6.4) nM around control implants and 1.7 (0.4-4.6) nM in the peri-implantitis group (p = 0.33). Patients' age correlated with sample volume and with cathepsin K normalized to the adsorbed volume of gingival crevicular fluid (R = 0.39; p < 0.01). Moreover, significant differences between male and female (p < 0.01, p < 0.01), and between mandible and maxilla (p < 0.05, p < 0.01), but not between buccal and lingual sites (p = 0.99, p= 0.93), were observed when analysed for the parameters adsorbed volume and absolute cathepsin K levels. CONCLUSION: Clinical parameters of peri-implantitis are associated with a higher amount of cathepsin K and a higher volume adsorbed to filters strips. To establish cathepsin K as a biochemical parameter to monitor peri-implant tissue health, age, sex and collection site should be considered to avoid interfering influences because of sample inhomogenity. Also a prospective study over time including more patients would be necessary.     

2种不同种植体植入对种植体周围软组织的影响

目的: 研究2种种植体对种植体周围软组织的影响。方法: 选择2020年12月—2021年2月普陀区眼病牙病防治所收治的单颗后牙缺失且需行种植修复的患者40例,其中植入骨水平种植体10例,软组织水平种植体30例。在完成种植冠修复当天、3个月、6个月及12个月时比较2组种植体的探诊深度,检测种植体龈沟液中天冬氨酸转氨酶（AST）和碱性磷酸酶（ALP）水平。采用SPSS 17.0软件包对数据进行统计学分析。结果: 修复完成当天、3个月、6个月及12个月,软组织水平种植体的探诊深度和ALP水平均显著低于骨水平种植体（P<0.05）。其中修复完成当天,软组织水平种植体的AST显著低于骨水平种植体（P<0.05）。随着时间增加,骨水平种植体龈沟液中的AST迅速降低,最后与软组织水平种植体接近（P>0.05）。结论: 尽管骨水平种植体和软组织水平种植体均具有良好的临床使用效果,但软组织水平种植体周围的软组织表现出更好的稳定性。