Calibration and reliability of the Periotron 6000 for individual gingival crevicular fluid samples

Inflammatory effects of individualized abutments bonded onto titanium base on peri-implant tissue health: A randomized controlled clinical trial

BACKGROUND

In implant prosthodontics, computer-assisted design and computer-assisted manufacturing (CAD/CAM) zirconia abutments bonded onto titanium bases are frequently used in prosthetic dentistry. Unpolymerized monomer of the bonding material or the adhesive gap itself may have a negative effect on peri-implant tissue health. However, evidence addressing this problem is not available.

PURPOSE

The aim of the current trial was to study inflammatory effects of individualized abutments bonded onto titanium bases.

MATERIAL AND METHOD

A total of 24 patients with one test abutment and one control abutment each participated in this prospective, double-blind, randomized controlled clinical trial. Thereby, test abutments were CAD/CAM titanium abutments bonded onto titanium abutments (Ti-Base). As control abutments individualized, one-piece CAD/CAM titanium abutments were used. At abutment installation as well as 6 and 12 months thereafter bone level changes, clinical parameters as well as Il-1β levels were assessed.

RESULTS

Neither for bone level or clinical parameters nor for Il-1β levels, significant differences between test and control abutments could be found. However, in both groups Il-1β levels were significantly elevated at both the 6 and 12 months follow-up compared to baseline.

CONCLUSION

Within the limits of this RCT, it can be concluded that effects on the inflammatory state of peri-implant tissues do not differ between individualized abutments bonded onto Ti-Bases and individualized one-piece abutments.

Comparing periodontitis biomarkers in saliva, oral rinse and gingival crevicular fluid: A pilot study

AIM

To explore the feasibility of screening for periodontitis by measuring biomarkers, namely total proteolytic activity (TPA), matrix metalloproteinase (MMP)-8, chitinase, lysozyme or their combination, in saliva, oral rinse and gingival crevicular fluid (GCF).

MATERIAL AND METHODS

Subjects were recruited among healthy/gingivitis individuals and untreated periodontitis patients in Academic Centre for Dentistry Amsterdam (ACTA). All participants donated samples of unstimulated whole saliva, oral rinse and GCF. The protein concentrations and MMP-8 levels were determined by ELISA. Enzymatic activities were measured using appropriate fluorogenic substrates.

RESULTS

In oral rinse samples, periodontitis patients (n = 19) exhibited significantly higher concentrations of MMP-8 and TPA than controls (n = 20). MMP-8 in combination with chitinase explained 88% of the variance and assigned a subject to control or periodontitis group, with best accuracy (87.2%) in oral rinse.

CONCLUSIONS

The combination of MMP-8 and chitinase in the current oral rinse procedure has the potential to discriminate periodontitis from periodontal health/gingivitis.

Impact of periodontal treatment on the RANKL/OPG ratio in crevicular fluid

Aim

Alveolar resorption is one of the most important events in periodontitis. Osteoclast activity is regulated by the ratio between receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG). The aim of this study was to evaluate changes in the RANKL/OPG ratio in crevicular fluid after periodontal treatment.

Material and methods

A total of 15 patients with periodontitis were included in the study group. Samples were collected from an area with active periodontitis and a healthy area. The RANKL and OPG levels were measured before and after periodontal scaling and root planing (SRP) treatment. The study group was compared to the control group, which included 10 patients without periodontitis. ID Clinicaltrial.gov: NCT03787875.

Results

A decrease in the RANKL level was found in areas with active periodontitis after periodontal treatment, but no change in the OPG level was observed.

Therefore, the treatment induced a decrease in the RANKL/OPG ratio in sites with destructive periodontal activity.

Conclusions

Periodontal treatment acts on the RANKL/OPG ratio by decreasing osteoclastogenesis. These results encourage the use of these molecules for periodontal diagnosis, monitoring and treatment.

ID Clinicaltrial.gov

NCT03787875.

Gingival Health of Porcelain Laminate Veneered Teeth: A Retrospective Assessment

STATEMENT OF PROBLEM

The long-term effect of the presence of porcelain laminate veneers (PLVs) on the health of the surrounding gingival issues is not available in the restorative literature.

PURPOSE

To assess the long-term effect of PLVs on the health of the surrounding gingival tissues. A secondary aim was to correlate gingival crevicular fluid (GCF) scores with clinical parameters used for gingival health assessment in teeth treated with PLVs.

METHODS AND MATERIALS

Patients who received PLVs placed at the Graduate Restorative Clinic within a seven- to 14-year period were recalled for clinical evaluations. Periodontal measurements including gingival index (GI), periodontal pocket depth (PPD), gingival recession (GR), and clinical attachment level (CAL) were measured using a standard probe and indices. Gingival Crevicular Fluid (GCF) was measured with a Periotron machine (Periotron 8000, Oraflow Inc), using Periopaper (Periopaper Gingival Fluid Collection Strip, Oraflow Inc.) for fluid collection. Photographs of any observed clinical defect were taken. Data were tabulated using Excel 2010 (Microsoft Corp). Statistical analysis for all descriptive statistics was performed using SPSS 21 (SPSS Software, IBM Corp.) and Stata SE 13 (Stata Software, StataCorp). Repeated-measures analysis of variance (ANOVA) was done to test for statistical significance of the mean pocket depths between the restored and unrestored surfaces of the veneered teeth. The significance level for all tests was p<0.05. Pearson's correlation coefficient was performed for testing statistical significance between GCF and GI and between GCF and PPD.

RESULTS

The frequency distribution of the GI included 47 PLVs (43%) with normal gingiva, 16 (15%) with mild inflammation, and 46 (42%) with moderate inflammation and bleeding on probing. The average PPD on the facial surface of the maxillary and mandibular PLVs was 2.17 mm and 2.16 mm, respectively. On the lingual surface, the average PPD was 2.10 mm for maxillary and 2.22 mm for mandibular PLVs. Gingival recession was seen in 27% of the evaluated PLVs. The repeated-measures ANOVA revealed p≥0.136, showing no statistical difference in the mean pocket depths between restored facial and unrestored lingual surfaces of the veneered teeth. A moderate correlation (r=0.407) was found between GCF and GI, which was significant at p<0.001. No correlation (r=0.124) was found between GCF and PPD, which was not significant at p=0.197.

CONCLUSIONS

Gingival response to the evaluated PLVs was in the satisfactory range, with overall GI scores ranging between normal and moderate inflammation, pocket depths ranging from 1 to 2 mm, and recession present in 27% of the evaluated PLVs. No statistically significant difference was found between the mean pocket depths of the restored and unrestored surfaces of veneered teeth (p≥0.136). A moderate correlation was found between GCF and GI.

Tumor Necrosis Factor-alpha in Gingival Crevicular Fluid as a Diagnostic Marker for Periodontal Diseases: A Systematic Review

OBJECTIVES

The aim of this systematic review was to evaluate human gingival crevicular fluid (GCF) tumor necrosis factor-alpha (TNF-α) as a potential biomarker for diagnosis of periodontal disease (International prospective register of systematic reviews [PROSPERO] number: CRD42015020199).

METHODS

An electronic search for TNF-α in human GCF was conducted until May 17, 2018. Data from systemically healthy patients with healthy periodontium or periodontal disease were incorporated. Risk bias was assessed by Newcastle-Ottawa Scale for case-control studies and Jadad scale for clinical trials.

RESULTS

Twenty-six studies were included (12 case-control studies, 7 clinical trials, and 7 randomized controlled trials). Most case-control studies showed increased TNF-α concentration in GCF of patients with periodontal disease. The clinical trials and randomized controlled trials demonstrated no consistent modification of TNF-α level after periodontal intervention.

CONCLUSION

The present data support the use of TNF-α in GCF as a potential biomarker for diagnosis of periodontal disease but not to monitor the healing after therapy.

Clinical and technical considerations in the analysis of gingival crevicular fluid

Despite the technical challenges involved when collecting, processing and analyzing gingival crevicular fluid samples, research using gingival crevicular fluid has, and will continue to play, a fundamental role in expanding our understanding of periodontal pathogenesis and healing outcomes following treatment. A review of the literature, however, clearly demonstrates that there is considerable variation in the methods used for collection, processing and analysis of gingival crevicular fluid samples by different research groups around the world. Inconsistent or inadequate reporting impairs interpretation of results, prevents accurate comparison of data between studies and potentially limits the conclusions that can be made from a larger body of evidence. The precise methods used for collection and analysis of gingival crevicular fluid (including calibration studies required before definitive clinical studies) should be reported in detail, either in the methods section of published papers or as an online supplementary file, so that other researchers may reproduce the methodology. Only with clear and transparent reporting will the full impact of future gingival crevicular fluid research be realized. This paper discusses the complexities of gingival crevicular fluid collection and analysis and provides guidance to researchers working in this field.

The Association Between Periodontal Inflammation and Labor Triggers (Elevated Cytokine Levels) in Preterm Birth: A Cross-Sectional Study

BACKGROUND

Periodontitis is considered to be a risk factor for preterm birth. Mechanisms have been proposed for this pathologic relation, but the exact pathologic pattern remains unclear. Therefore, the objective of the present study is to evaluate levels of four major labor triggers, prostaglandin E2 (PGE2), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, in gingival crevicular fluid (GCF) and serum samples between women with preterm birth (PTB) and full-term birth (FTB) and correlate them with periodontal parameters.

METHODS

PGE2, IL-1β, IL-6, and TNF-α levels were estimated using enzyme-linked immunosorbent assays in GCF and serum samples collected 24 to 48 hours after labor from 120 women (60 FTB, 60 PTB).

RESULTS

Women with PTB exhibited significantly more periodontitis, worse periodontal parameters, and increased GCF levels of IL-6 and PGE2 compared with the FTB group; there were no significant differences in serum levels of measured markers. GCF levels of IL-1β, IL-6, and PGE2 and serum levels of TNF-α and PGE2 were significantly higher in women with periodontitis compared with periodontally healthy women. Serum levels of PGE2 were positively correlated with probing depth (PD) and clinical attachment level (CAL) as well as with GCF levels of TNF-α in women with PTB.

CONCLUSIONS

Women with PTB demonstrated worse periodontal parameters and significantly increased GCF levels of IL-6 and PGE2 compared with those with FTB. Based on significant correlations among serum PGE2 and PD, CAL, and GCF TNF-α in PTB, periodontitis may cause an overall increase of labor triggers and hence contribute to preterm labor onset.

Evaluation of beta-2 microglobulin and alpha-2 macroglobulin levels in patients with different periodontal diseases

BACKGROUND

Beta-2 microglobulin (B2M) and alpha-2 macroglobulin (A2M) play key roles in the immune system. The aim of this study was to compare B2M and A2M levels in patients with different periodontal diseases.

METHODS

Eighty patients (20 periodontally healthy, 20 with gingivitis, 20 with chronic periodontitis and 20 with generalized aggressive periodontitis) were enrolled in the study. The analysis of B2M and A2M was performed on gingival crevicular fluid (GCF) using an enzyme-linked immunosorbent assay in GCF.

RESULTS

The total levels of B2M and A2M were statistically lower in the periodontally healthy group than in the other groups (p < 0.05) and significantly higher in the generalized aggressive periodontitis group compared to the other groups (p < 0.05).

CONCLUSIONS

B2M and A2M play key roles in the balance between periodontal health and disease. It is proposed that tissues release B2M and A2M to stop inflammation and inhibit the proliferation of microorganisms and this may be the reason for the high levels of B2M and A2M in the generalized aggressive periodontitis and chronic periodontitis groups. B2M and A2M are assumed to be user-friendly and cost-effective markers for periodontal disease to identify asymptomatic diseases.

Repeatability of gingival crevicular fluid collection and quantification, as determined through its alkaline phosphatase activity: implications for diagnostic use

BACKGROUND AND OBJECTIVE

In spite of four decades of studies on gingival crevicular fluid, no data have been reported on the repeatability of gingival crevicular fluid collection and the subsequent quantification procedures. The present study reports, for the first time, on the repeatability and method error of gingival crevicular fluid collection and quantification, as determined through its alkaline phosphatase (ALP) activity. Diagnostic considerations are then explored.

MATERIAL AND METHODS

Twenty-seven healthy subjects (17 women and 10 men; mean age ± SD, 21.2 ± 4.8 years) with optimal periodontal status were enrolled according to a blind prospective design. The gingival crevicular fluid was collected at baseline, and after 1 d, 1 wk and 3 mo. At each clinical session, two consecutive rounds of gingival crevicular fluid collection were made from each of the four maxillary incisors, allowing the recovery of resting and flow gingival crevicular fluid. The total ALP activities were determined spectrophotometrically, and repeatability and method errors for the resting, flow and overall (resting + flow) gingival crevicular fluid ALP activities were calculated, relative to the corresponding baseline levels.

RESULTS

No significant differences were seen over time, although the flow gingival crevicular fluid ALP activity was generally lower than that for the resting gingival crevicular fluid. The method errors ranged from 40 to 58%, with the flow and overall gingival crevicular fluid activities showing the highest and lowest errors, respectively.

CONCLUSION

Reliable use of the gingival crevicular fluid ALP collection and quantification, both in research and diagnosis on an individual basis, should take into account relevant errors, and variations are to be considered as true only above relevant thresholds.

Application of the checkerboard immunoblotting technique to the quantification of host biomarkers in gingival crevicular fluid

BACKGROUND

The aim of this study was to describe the development and validation of the checkerboard immunoblotting (CBIB) technique for the high-throughput quantification of multiple inflammatory mediators in gingival crevicular fluid (GCF) samples.

METHODS

Monoclonal antibodies were used to bind GCF interleukin (IL)-1beta and -8 and matrix metalloproteinase (MMP)-8 to the surface of membranes. Biotinylated antibodies were used to detect bound antigens in a checkerboard format. Signals were developed using chemiluminescence, captured on film, and quantified using software for array analysis. The assay was tested for potential cross-reactions among the three pairs of antibodies. Eleven CBIBs were processed to determine the analytical sensitivity of the assay. Forty GCF samples were analyzed using CBIB and enzyme-linked immunosorbent assay (ELISA) in parallel, and the significance of the correlations among the results was tested using the Pearson correlation coefficient. Nine hundred thirty-one GCF samples were collected from 20 periodontally healthy subjects and 20 periodontitis subjects and analyzed using CBIB to test the assay's sensitivity and dynamic ranges using clinical samples.

RESULTS

The CBIB was capable of distinguishing among the three analytes. The sensitivity and dynamic ranges of the assay were suitable for the detection of the three targets in the majority of GCF samples. There were highly statistically significant (P <0.0001) positive correlations between CBIB and ELISA data for all three biomarkers. The periodontitis subjects had statistically significantly higher mean levels of IL-1beta and -8 compared to healthy subjects.

CONCLUSION

The CBIB technique is a sensitive and specific assay for the high-throughput quantification of MMP-8 and IL-8 and -1beta in GCF.

Impact of the Distinct Sampling Area on Volumetric Features of Gingival Crevicular Fluid

BACKGROUND

Volumetric features of gingival crevicular fluid (GCF) are under the influence of many factors, including sampling variables. Standardizing such factors may enable a more precise methodology. Thus, analysis of the possible impact of the clinical periodontal status and the distinct location of sampling sites on fluid volume was performed.

METHODS

Clinical parameters were recorded, and fluid samples were obtained from 931 maxillary sites. The potential site-specific volumetric differences among healthy, gingivitis, and periodontitis sites; between multirooted or single-rooted teeth and mesio-buccal or disto-buccal sampling sites; and the correlations between volume and clinical measures were statistically analyzed.

RESULTS

Although volume increased in a disease-related pattern (healthy < gingivitis < periodontitis; P <0.05), the distribution range of volume was widespread, with prominent overlaps between the different clinical periodontal conditions. Multirooted teeth presented more fluid volume, and even mesio-buccal or disto-buccal sites exhibited some volumetric differences (P <0.05). Constant correlations between volume and clinical parameters could be observed only at gingivitis sites (P <0.05).

CONCLUSIONS

The spectrum of fluid volume is disease related in general. However, the wide range of volumetric distribution, the site-specific nature, and the clear impact of the distinct sampling site on volume are important volumetric features of this biologic fluid. Whenever possible, standardization of the extent of probing depth, degree of gingival inflammation, and distinct sampling area is likely to improve the reliability of GCF methodology.

Radioimmunoassay quantification of adrenomedullin in human gingival crevicular fluid

OBJECTIVE

To investigate whether adrenomedullin (ADM), a multifunctional peptide with key roles in host antimicrobial defence and inflammation, was present and quantifiable in human gingival crevicular fluid (GCF) and to study its relationship with periodontal health and disease.

DESIGN

GCF samples (30s) were collected using perio-paper strips from one diseased site in 21 subjects with periodontal disease and one healthy site from 19 control subjects with no evidence of periodontal disease. Samples were analysed by radioimmunoassay using a specific anti-human ADM antibody.

RESULTS

Measurable adrenomedullin-like immunoreactivity (ADM-LI) was present in all the GCF samples collected. ADM-LI was significantly higher in periodontitis sites (mean 493.6 pg) than in control healthy sites (mean 248.5 pg), p = 0.0016.

CONCLUSION

It is concluded that ADM is present in GCF at levels at which it could have an antibacterial role in the gingival crevice and modulate the pathophysiology of periodontal inflammation.

Quantitative analysis of substance P, neurokinin A and calcitonin gene-related peptide in gingival crevicular fluid associated with painful human teeth

The aim of this study was to investigate the presence of substance P (SP), neurokinin A (NKA) and calcitonin gene-related peptide (CGRP) in the gingival crevicular fluid of teeth diagnosed with pain of pulpal origin compared with clinically healthy teeth, and to detect any changes in the levels of these neuropeptides in gingival crevicular fluid after removal of the pulp from the painful teeth. Gingival crevicular fluid was collected at baseline from one interproximal site at a painful and a non-painful contralateral tooth from 54 adult patients. Sampling was repeated after 1 wk in a subset of 21 subjects. Samples were analysed for SP, NKA, and CGRP using radioimmunoassay. The mean levels of SP and NKA were significantly higher in gingival crevicular fluid from painful teeth compared with non-painful teeth. The level of SP in the GCF of painful teeth fell significantly 1 wk after pulpectomy. In contralateral teeth, there were no significant differences in the levels of SP and NKA after 1 wk. It is concluded that SP and NKA are present in significantly greater amounts in the GCF of painful teeth compared with healthy teeth.

Development of a method to detect and quantify prostaglandin E2 in pulpal blood from cariously exposed, vital primary molar teeth

AIM

The aim of this in vitro study was to detect and quantify an established marker of inflammation, prostaglandin E2 (PGE2), in blood samples harvested from radicular pulp stumps after coronal pulp amputation.

METHODOLOGY

Harvesting was achieved by a paper strip 'dip-stick' method and the volume of each sample estimated before storage at -80 degrees C. A competitive, plate-based enzyme immunoassay technique (EIA) was developed for detection and quantification of the inflammatory mediator assumed to be present in blood samples. Since this technique had not previously been used to assess pulp blood, steps in the development of harvesting, storage, extraction and validation of this sensitive assay are described.

RESULTS

Thirty-nine single-blood samples were assayed and yielded detectable amounts of PGE2 ranging from 1.0 to 2641 ng mL-1.

CONCLUSIONS

The results of this investigation indicate that the inflammatory mediator, PGE2 can be detected and quantified in small blood samples from pulp stumps. Further development may derive quantitative tests for determining the condition of pulp tissue in primary molar pulp treatment.

Calibration of the Periotron 8000 and 6000 by polynomial regression

This paper reports the detailed calibration of the new Periotron 8000 with different fluids and uses the method of least squares to derive polynomial regression equations up to the 6th order, to investigate the most accurate descriptor of the resulting calibration lines. The use of a 4th order polynomial regression equation (recommended by the manufacturer) provided better coefficients of determination (R2: 0.999) and root mean square errors (RMSE = 1.6) than either linear regression (R2: 0.986, RMSE = 10.9) or quadratic models (R2: 0.998, RMSE = 3.2). Data derived using the manufacturer's MLCONVERT software program lacked accuracy and incurred large errors for volumes > 0.5 microliter. Calibrations performed on one day could be used with accuracy to derive volumes > 0.1 microliter collected on subsequent days, when using the same machine (s.d. for residuals plot = 2.49 Periotron units), but this was not the case for different machines (s.d. = 9.57 Periotron units). Varying serum protein concentration by up to 500% had a negligible effect on calculated volumes above 0.1 microliter. We conclude that the Periotron 8000 is at least as reliable a machine as the Periotron 6000, and that the calibration lines for both machines are best described using 4th order polynomial regression equations and "look-up" tables, rather than quadratic (Periotron 6000) or the manufacturer's software (Periotron 8000). Serum seems to be an acceptable GCF substitute for calibrations, which can be performed 1 day, and used on subsequent days for a given machine and for volumes above 0.1 microliter.

The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus in humans 1 year after 4 randomized treatment modalities

The relationship between probing attachment changes in treated periodontal pockets and the prevalence of selected periodontal pathogens was assessed in 10 patients with adult periodontitis 1 year following randomized therapy. All patients had at least 1 tooth in each quadrant with an inflamed pocket of probing depth > or =5 mm and clinical attachment loss and harbored at least one of the following 3 major periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, or Bacteroides forsythus. The number of target organisms per site was determined preoperatively; at 1 week; and at 1, 3, 6, and 12 months postoperatively utilizing DNA probes. The following clinical parameters were measured and recorded preoperatively and at 1, 3, 6, and 12 months post-treatment: gingival fluid flow, gingival index, plaque index, probing depth, probing attachment level, gingival recession, and bleeding on probing. One quadrant in each patient was randomly assigned to 1 of the following 4 treatments: 1) scaling and root planing; 2) pocket reduction through osseous surgery and apically-positioned flap; 3) modified Widman flap; and 4) modified Widman flap and topical application of saturated citric acid at pH 1 for 3 minutes. All 4 treatments were rendered in one appointment using local anesthesia. No postoperative antibiotics were used, but patients rinsed with 0.12% chlorhexidine for the first 3 months postoperatively and received a prophylaxis every 3 months. This investigation revealed: 1) 30.0% of the sites were infected by at least 1 species at 3, 6, and 12 months postoperatively. 2) Failing sites were infected by a high number of both Pg and Bf These sites had a mean of 24.2+/-9.0 x 10(3) Pg and 93.1+/-42.0 X 10(3) Bf while stable sites had a mean of 6.8+/-0.5 x 10(3) Pg and 7.2+/-1.2 x 10(3) Bf (P = 0.06 and P = 0.05, respectively). 3) The infected sites lost significantly more mean clinical attachment at 12 months (1.5+/-0.5 mm compared to a loss of 0.2+/-0.3 mm for uninfected sites, P = 0.017). 4) The infected sites had a significantly greater BOP (67+/-14% versus 25+/-8% for uninfected sites at 12 months, P = 0.012). 5) The choice of treatment modality did not affect the prevalence of the target species at 1 year post-treatment. These results suggest that prevalence of microbial pathogens negatively affects the 1 year outcome of periodontal surgical and nonsurgical therapy.

Periotron 8000: calibration characteristics and reliability

The Periotron is an instrument designed to quantify submicrolitre volumes of fluid sampled on a filter paper strip. To date 3 models have been manufactured: the Periotron 600 (1976), the Periotron 6000 (1983) and more recently the Periotron 8000 (1995). This paper investigated for the first time the calibration characteristics and reliability of the Periotron 8000. The fluids under investigation were: de-ionised water, human serum, fetal bovine serum and an ultrafiltrate of fetal bovine serum. Quantitative analysis was studied by recording a series of Periotron readings over a volume range of 0-1.0 microliters for each fluid. The average of 5 Periotron values for each particular fluid was then plotted versus the respective fluid volume. Qualitative changes in fluid composition versus Periotron Scores were also analysed. Volume conversion for Periotron scores using both Periotron MLCONVRT software and a best fit equation selected from TableCurve 2D software compared well. The results of this study revealed that: 1) differences in calibration fluid composition (e.g. protein content) are reflected in the Periotron scores; 2) positioning of filter paper strip between the jaws of the Periotron should be standardised, 3) calibration of the Periotron 8000 seems to be consistent over a 1-wk interval.

Experimental gingivitis in periodontitis-susceptible subjects

The purpose of this study was to evaluate clinical, microbiological, and gingival crevicular fluid (GCF) profiles in periodontitis-resistant and periodontitis-susceptible subjects during 4 weeks of experimental gingivitis. Experimental groups of similar ages were defined as gingivitis controls (GC; n = 10) and history of rapidly progressive periodontitis (RPP; n = 10), respectively. Prior to baseline, all subjects achieved good plaque control (plaque index (P1I) approximately 0) and gingival health (gingival index (GI) = 0), and had probing depths < or = 4 mm on experimental teeth. For 4 weeks after baseline, oral hygiene around maxillary 2nd premolar and 1st molar teeth was inhibited by a plaque guard. The plaque guard was removed weekly for GCF sampling to determine interleukin (IL)-1 beta and prostaglandin (PG)E2 amounts by ELISAs. In addition, P1I, GI, probing depth, and gingival recession measurements were made. Subgingival plaque darkfield microscopy and DNA probe analysis also were performed. Results indicated that clinical signs of inflammation, microbiological patterns and GCF profiles progressed similarly in both groups. However, plaque accumulated more rapidly in the susceptible subjects. P1I in RPP at 4 weeks was 2.1 +/- 0.1 compared to 1.5 +/- 0.2 in GC, with an incidence of P1I > of 100% versus 50%, respectively (logistic regression; p < 0.0001). Hence, the clinical, microbiological and host factors selected for this study were unrelated to previous susceptibility to periodontitis when evaluated in the experimental gingivitis model. However, the increased rate of plaque accumulation, following thorough plaque removal, in RPP patients suggests a potential factor in disease recurrence in these susceptible subjects.

The survival rate of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus following 4 randomized treatment modalities

The overall goal of this clinical study was to determine the short-term anti-infective effects of four randomized treatment modalities on Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Bacteroides forsythus (Bf) and determine the effects of bacterial survival on treatment outcomes in patients with adult periodontitis. Twelve adult patients requiring therapy for moderate periodontitis were selected for this study. All patients had at least one tooth in each quadrant that had an inflamed pocket of probing depth > or =5 mm with probing attachment loss that harbored at least one of the following three periodontal pathogens: Aa, Pg, or Bf. The number of target organisms per site was determined pre-operatively, at 1 week, and 1 month and 3 months postoperatively utilizing DNA probes. One quadrant in each patient was randomly assigned to each one of the following four treatment groups: 1) scaling and root planing (SRP group); 2) pocket reduction through osseous surgery and apically-positioned flap (OS group); 3) modified Widman flap (MWF group); and 4) modified Widman flap and topical application of saturated citric acid at pH 1 for 3 minutes (CA group). The 4 treatment modalities were performed in one appointment. No postoperative antibiotics were used. Patients were instructed to supplement their daily oral hygiene with chlorohexidine oral rinse during the study. The results of this investigation indicated that: 1) none of the treatment modalities was effective in eliminating the target species; 2) the incidence of infected sites for all groups was 100% preoperatively; 62.5%, 33.3%, and 31.3% at 1 week, and 1 and 3 months postoperatively, respectively; 3) these infected sites lost 1.1 +/- 0.4 mm of probing attachment compared to gain of 0.0 +/- 0.3 mm for uninfected sites; 4) the infected sites had higher plaque and bleeding on probing 0.9 +/- 0.3, 73 +/- 12%, respectively, compared to 0.3 +/- 0.1 and 30 +/- 8% for the uninfected sites; and 5) no statistically significant differences were detected among the infected sites in regard to gingival index (1.0 +/- 0.2 vs. 0.8 +/- 0.1) or probing depth (3.5 +/- 0.4 vs. 3.0 +/- 0.1 mm). These results indicate that bacterial survival negatively affects the short-term clinical outcomes of non-surgical and surgical periodontal therapy.

Enhanced chemiluminescent assay for measuring the total antioxidant capacity of serum, saliva and crevicular fluid

This paper reports the development of an enhanced chemiluminescent (ECL) assay for measuring the total antioxidant (AO) capacity of serum, saliva and a fluid collectable from the gum margin called gingival crevicular fluid (GCF). The theory behind the assay is explained, and the optimum conditions for the assay, and for storage of reagents and clinical samples is described. Calibration lines were linear (R > or = 0.99; P < 0.0001) and the within batch coefficient of variations for a water soluble vitamin E analogue (Trolox), serum and saliva samples were < 5%. In saliva and GCF, a characteristic AO response not seen in serum of the same patients, was identified. Total peripheral (serum) and local (saliva) AO capacities (mumol/L Trolox) were investigated in patients with (n = 18) and without (n = 16) adult periodontitis. Serum AO status did not differ between groups. Salivary total AO concentrations were lower in the peridontitis (P) group [175 (53) mumol/L] than in the non-periodontitis (NP) group [254 (110) mumol/L1: P < 0.01], as were saliva:serum AO ratio's [0.37 (0.11) versus 0.5 (0.18): P < 0.01]. Periodontitis patients may have a reduced salivary AO concentration, which could result from, or predispose to, the damaging effects of reactive oxygen species (ROS). The potential for ROS production in the oral and periodontal environment may explain the presence of a specific antioxidant in oral fluids that is not detectable in serum. The ECL assay described provides a rapid, simple and reproducible method of measuring total antioxidant defence in small volumes of biological fluids.

Interleukin-1 alpha, interleukin-8 and interferon-alpha levels in gingival crevicular fluid

Cytokines play an important role in the pathology associated with chronic inflammatory diseases. We measured the total amounts [picograms (pg)] and concentrations.(pg/microliter) of interleukin-1 alpha (IL-1 alpha), interleukin-8 (IL-8) and interferon-alpha (IFN-alpha) in 20 s gingival crevicular fluid (GCF) samples obtained from 2 diseased and 2 healthy sites in 20 subjects with periodontitis, and from 2 healthy sites in 20 subjects without disease. Both the mean amount and concentration of IL-1 alpha were significantly higher (p < 0.001) in diseased sites compared to healthy sites in subjects with disease. The results for IL-8 and IFN-alpha differed depending on the method of reporting. Whereas the amount of IL-8 was significantly higher (p < 0.01) in diseased sites, the mean concentration of IL-8 was lower compared to healthy sites. The mean amount of IFN-alpha was similar in health and disease; however, the concentration of IFN-alpha was significantly lower in diseased sites (p < 0.001) corresponding to the significant increase in crevicular fluid volume (p < 0.001). There were no significant differences in the amount or concentrations of the 3 cytokines between healthy sites from subjects with disease and healthy sites from healthy controls. The total amounts of both IFN-alpha and IL-8 were correlated between healthy and diseased sites in subjects. These data suggest that, while the disease status of a site is the major determinant of the levels of these cytokines locally, subjects with high levels of IL-8 and IFN-alpha in healthy sites also tend to have high levels of these cytokines in diseased sites. Finally, both the concentrations and total amounts of IL-8 and IFN-alpha were significantly correlated in diseased sites, suggesting that levels of these two cytokines rise or fall in tandem. The combination of decreased IL-8 and decreased IFN-alpha concentrations at diseased sites may reflect the reduced anti-bacterial host defense activity at that site.

Efficacy of a sonic toothbrush on inflammation and probing depth in adult periodontitis

This single-blind, 8-week study compared the efficacy of a sonic toothbrush and a manual brush in 40 patients with adult periodontitis. Qualitative clinical indices and quantitative laboratory methods were used to monitor the periodontal status of 3 pockets 5 to 7 mm deep in each subject. Patients were randomly assigned either a sonic or manual toothbrush. The two groups were comparable with respect to age, gender, and anatomical location of the test sites. Data were collected from all sites at baseline and at 2, 4, and 8 weeks. Over the 8-week period, both groups showed significant improvements in the clinical indices used. Descriptive statistics indicated the sonic brush group had greater improvement than the manual group in the clinical parameters (gingival index, bleeding index, probing depth, and clinical attachment level). Gingival crevicular fluid (GCF) flow was significantly lower in the sonic brush group (P = 0.018). Considerable variation was present in the levels detected for both inflammatory cytokines tested, however, concentration of interleukin-1 beta was significantly lower in the GCF of sonic group patients (P = 0.05), while concentration of interleukin-6 was significantly reduced in both groups (P < or = 0.05) (t tests). Under these conditions, there is some evidence to suggest that the sonic toothbrush is more beneficial in resolving inflammation in patients with moderate periodontal disease.

Chemiluminescent assay of alkaline phosphatase in human gingival crevicular fluid: investigations with an experimental gingivitis model and studies on the source of the enzyme within crevicular fluid

The purpose of this study was to investigate how levels of gingival crevicular fluid (GCF) alkaline phosphatase (ALP) change in relation to levels of plaque and gingival inflammation in 20 adults during a 21 day period of experimental gingivitis. The source of ALP within GCF was also investigated using a repeat sampling protocol; by determining enzyme levels derived from 30 putative periodontal pathogenic and non-pathogenic species; and by examining inhibition profiles from a variety of host and bacterial ALP isoenzymes. Total 30-s GCF ALP levels increased significantly (p < 0.002) during experimental gingivitis and preceded an increase in gingival index (GI) by approximately 7 days. Enzyme levels correlated with GCF volume (R = 0.7; p < 0.0001), but repeat sampling indicated that entry of ALP into the gingival crevice was independent of the rate of fluid flow. Only 5 of the bacterial species investigated produced clearly detectable levels of ALP in culture supernatants, these were P. gingivalis (381), P. intermedia (581), P. nigrescens (8944), Dentin P. gingivalis (TW 471: clinical isolate) and C. ochracea (25). Levamisole inhibition and studies on suspensions of washed plaque demonstrated that host-derived ALP contributed to > 80% of the enzyme in GCF. We conclude that elevated 30-s GCF ALP levels measured using the chemiluminescent assay reported, are detectable before increases in gingival indices and appear to be a better marker of gingival inflammation than ALP concentrations. The major source of ALP within GCF is host derived and in early inflammatory disease is likely to be of polymophonuclear leukocyte origin.