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Table of Contents   
ORIGINAL RESEARCH  
Year : 2019  |  Volume : 30  |  Issue : 5  |  Page : 736-741
Gingival crevicular fluid response to protocols of non-surgical periodontal therapy: A longitudinal evaluation


1 Private Practice, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
2 Department of Periodontics, School of Dentistry, Lutheran University of Brazil, Canoas, RS, Brazil
3 Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil

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Date of Submission04-Mar-2016
Date of Decision28-Apr-2018
Date of Acceptance16-Oct-2018
Date of Web Publication18-Dec-2019
 

   Abstract 


Context and Aim: Gingival crevicular fluid (GCF) volume reflects the level of periodontal inflammation. This secondary analysis aimed to evaluate the GCF volume in patients submitted to non-surgical periodontal therapies under a split-mouth design. Materials and Methods: GCF volume of 25 participants (47.24 ± 6.47 years) with moderate-to-severe chronic periodontitis was collected at Days 0, 30, 60, 90, 120, 270, and 450. The participants were submitted to three different non-surgical therapies randomly assigned per quadrant [GI: supragingival control (Supra) as only intervention (one quadrant); GII: Supra plus scaling and root planing (SRP) on Day 0 (two quadrants); GIII: Supra on Day 0 and SRP 30 days later (one quadrant)]. During treatment (0–60 days) and maintenance (90–450 days) participants were submitted to supragingival plaque control reinforcements. GCF volumes were analyzed after logarithmic transformation (log10) and linear models were used for intra- and inter-group comparisons, considering the data dependence. Results: Baseline GCF volumes were similar between groups (GI: 0.39 ± 0.22 μl; GII: 0.42 ± 0.26 μl; GIII: 0.41 ± 0.14 μl;P > 0.05). At Day 60, GCF volumes were significantly reduced (GI: 0.20 ± 0.13 μl; GII: 0.18 ± 0.11 μl; GIII: 0.22 ± 0.13 μl; P < 0.001), without inter-groups differences. These results were maintained along maintenance period (P > 0.05). Even in sites bleeding on probing (BOP) + the means of GCF volume did not differ between groups (P > 0.05). Conclusions: All therapies determined reductions on the GCF volume along time. Supragingival plaque control modulated the subgingival area during the study, reinforcing the importance of this control over the subgingival inflammatory response.

Keywords: Crevicular fluid, longitudinal study, periodontal disease, root planing, supragingival scaling

How to cite this article:
Rossi V, Romagna R, Angst PD, Gomes SC. Gingival crevicular fluid response to protocols of non-surgical periodontal therapy: A longitudinal evaluation. Indian J Dent Res 2019;30:736-41

How to cite this URL:
Rossi V, Romagna R, Angst PD, Gomes SC. Gingival crevicular fluid response to protocols of non-surgical periodontal therapy: A longitudinal evaluation. Indian J Dent Res [serial online] 2019 [cited 2020 Aug 5];30:736-41. Available from: http://www.ijdr.in/text.asp?2019/30/5/736/273415



   Introduction Top


Several indicators are used to monitor the periodontal inflammatory response that is triggered by biofilm accumulation.[1],[2],[3] Among the immunological indicators that are currently available, the simplest and most affordable is the gingival crevicular fluid (GCF) volume,[1],[4],[5],[6] which has direct association with the clinical condition of the patient.[7],[8],[9],[10] This relationship is likely due to an increased production of GCF reflecting increased vascular permeability[5],[11] or increase in probing depth (PD).[12] Indeed, Lamster and Ahlo[13] reported that moderately or severely inflamed sites exude a larger volume of GCF than healthy or less-inflamed sites. However, although this is a good indicator of periodontal response and clinical stability over time,[12] few longitudinal studies have evaluated the effects of different treatment protocols on the volume of GCF.

To the best of our knowledge, although studies have evaluated the effects of a combined supra- and subgingival intervention on GCF volume,[14],[15],[16],[17],[18] only Gomes et al.[19] have monitored changes in the GCF volume in periodontal patients as an indicator of the subgingival response to a comprehensive 6-month supragingival plaque control regimen. Interestingly, reductions in GCF volume during this time (0.20–0.36 μl) were comparable to those reported following scaling and root planing (SRP).[15],[16],[17],[18] However, only limited comparisons can be made between these studies given the differences in the study protocols, goals of the oral hygiene instructions, and sample characteristics. To address this, Gomes et al.[20] used a split-mouth design, whereby patients with gingivitis plus moderate-to-advanced chronic periodontitis received three different types of non-surgical therapy (supragingival control alone versus two procedures that included subgingival instrumentation). Professional supragingival plaque control supervision was provided throughout the experimental period of 450 days. As expected, the therapies that included SRP resulted in greater reductions in PD and in the percentage of sites with bleeding on probing (BOP) and a greater attachment gain from Days 0 to 60. Nevertheless, the supragingival control also promoted significant reductions in all clinical indicators evaluated and these results were maintained over 1 year (90–450 days) for all experimental groups. Therefore, the use of GCF volume to evaluate the outcomes of such therapies may provide additional information, since this reflects subclinical inflammation.

The aim of this study was to monitor changes in the GCF volume in periodontal patients subjected to different non-surgical therapies. It was hypothesized that the GCF volume would respond in a similar way in all patients, regardless of the treatment protocol administered.


   Materials and Methods Top


Study design and ethical considerations

This study was a secondary analysis of a randomized clinical trial using a split-mouth design that comprised treatment (Days 0–60) and maintenance (Days 90–450) phases. The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of the Lutheran University of Brazil, Canoas, Brazil (ULBRA; #2002-324H). All participants signed an informed consent prior to the study commencing and, due to the longitudinal nature of the study, participants were guaranteed that they would receive immediate treatment should attachment loss occur during the study.[21]

Sample

Sample size calculation was performed based on the results reported by Gomes et al.[22] This indicated that 25 patients needed to be included to detect a difference of 1 mm (standard deviation: ±1 mm) in the mean PD reduction and a significant treatment effect (power = 80%; alpha = 5%).

Participants were enrolled consecutively at the School of Dentistry of ULBRA between May 2008 and October 2009. The following eligibility criteria were used: absence of a systemic condition that could affect the treatment and periodontal outcomes (smoking habit, diabetes, or cardiovascular disease with antimicrobial prophylaxis indicated); negative history of previous periodontal treatment and/or maintenance in the 6 months preceding the study; negative history of anti-inflammatory drug and/or antibiotic use in the 3 months prior to the initial consultation; no current prescription for chemical agents that control supragingival biofilm; and no pregnancy.

Patients who met the eligibility criteria underwent a full-mouth periodontal screening examination, with those who met the following criteria being considered for inclusion: diagnosis of moderate-to-severe generalized chronic periodontitis; presence of at least four teeth in each quadrant, excluding the third molars and teeth with furcation involvement or endo-periodontal lesions; and at least two sites in distinct teeth and in each quadrant with gingivitis (marginal bleeding) plus periodontitis (attachment loss plus BOP). In addition, there needed to be a difference of <2 mm in PD and clinical attachment level (CAL) values between these sites.[23]

During the study, participants were excluded if they developed systemic conditions that could interfere with the treatment and/or outcomes, if they failed to adhere to appointments for recalls, and/or if they experienced loss of periodontal attachment.

[Table 1] presents the baseline demographic and clinical data for the participants in this study, as previously reported.[20]
Table 1: Demographic data (n=25) and periodontal indicators according to treatment groups (supragingival control, supragingival control plus subgingival intervention on day 0, and supragingival control on Day 0 and subgingival intervention 30 days later) at baseline

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Examiner reproducibility

The examiner calibration process has been described previously.[20] Two examiners who were blinded to group allocation and were not involved in the treatment phase obtained weighted (±1 mm) kappa scores of >0.68 for PD and CAL in both the intra- and inter-examiner reliability assessments.

Experimental procedures

Data collection

GCF volume measurement and periodontal examinations occurred, for all experimental groups, at Days 0 (baseline), 30, 60, 90, 120, 270, and 450.

GCF sampling was performed at two sites that were randomly selected from those sites with a diagnosis of gingival bleeding and periodontitis and the highest PD per quadrant at the time of the screening examination. First, the supragingival biofilm was gently removed, following that the area was lightly washed and dried using an air/water spray syringe, and isolated using cotton rolls. Paper strips (PS) were then inserted into the sulcus/pocket and held in place for 30 s. The amount of GCF collected was immediately measured in millimeters.[24] Any PS that presented with blood were discarded and a new sample was collected.

Full-mouth visible plaque and gingival bleeding indices (VPI and GBI, respectively),[25] PD, CAL, and BOP were assessed at six sites per tooth (mesiobuccal, buccal, distobuccal, mesiolingual, lingual, and distolingual) using a Williams millimeter probe (#5; Neumar, São Paulo, SP, Brazil). PD and CAL were rounded up to the nearest whole millimeter.

Allocation to treatment groups

In each participant, the quadrants were randomly allocated to a different treatment regimen by a researcher (Sabrina Carvalho Gomes) who was not involved in the clinical examinations or interventions drawing two coins. The following treatments were allocated:

  • Group I (GI): One quadrant received supragingival control, which consisted of supragingival scaling and oral hygiene instructions (Supra). This intervention was performed on Day 0 and was maintained exclusively until Day 450
  • Group II (GII): Two quadrants received Supra plus subgingival SRP (sub) under anesthesia on Day 0. Supra was then performed through the rest of the study period
  • Group III (GIII): One quadrant received Supra on Day 0 followed by sub 30 days later. Supra was also performed throughout the study period.


Therapeutic interventions

A specialist in periodontics (Rachel Romagna) provided treatments on Days 0–60, while another periodontist (Vanessa Rossi), who was blinded to the group allocation, provided Supra to all quadrants on Days 90–450. A flowchart for the study is presented in [Figure 1].
Figure 1: Flowchart of the study

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On Day 0, after data collection, each of the participants underwent Supra in all quadrants. Supragingival scaling consisted of debridement of any biofilm/calculus up to the gingival margin using hand instruments (Gracey Curettes #3–4, 11–12, 13–14; Neumar, São Paulo, SP, Brazil) followed by dental polishing (with rubber cups and abrasive paste). Oral hygiene instructions were then provided that included the use of toothbrushes, floss, and/or interdental brushes according to the individual's needs, as evaluated by means of the VPI and GBI.[25] Those quadrants that had been allocated to GII and GIII were then subjected to subgingival SRP (i.e., the debridement of subgingival biofilm and calculus using hand instruments) on Day 0 and 30, respectively.

Patients were re-evaluated on a weekly basis from Day 0 to 30, and on Days 60 and 90. From Day 120 onward, re-evaluations were performed on an average of every 2.2 ± 1.64 months. At these times, all patients received Supra and oral hygiene re-instructions based on the VPI and GBI results at each appointment.

Statistical analysis

GCF volume measurements were converted from millimeters to Periotron® units and then microliters, as previously described,[24],[26] prior to analysis. An average was then generated for each quadrant by individual and by treatment group.

Among the 25 participants in this study, 3 did not complete the study: one moved to another state, one refused to participate in the longitudinal phase, and one became pregnant. Therefore, intention-to-treat analysis was performed, giving a final sample size of 25 individuals.

Homogeneity of the data was verified using the Kolmogorov–Smirnov test. The GCF data did not follow a normal distribution and so were log10 transformed. Linear models for repeated measures were used to compare the means and standard deviations for all sites as well as for only those sites that exhibited BOP (BOP + sites) through time, taken into account the grouping of teeth (GI, GII, GIII) within the same individuals. The Bonferroni post hoc test was then used wherever necessary. Data analysis were performed with the SPSS v. 18.0 (SPSS Inc., Chicago, IL, USA) using a significance level of 5%.


   Results Top


Changes in the log10 GCF volume through time are shown in [Table 2]. All groups responded to their treatment with significant reductions in GCF volume being observed throughout the study (P < 0.001), but particularly from Day 0 to 60. There were no significant differences in GCF volume between groups at any time.
Table 2: Mean±standard deviation and 95% CI of the gingival crevicular fluid volume (log10) along time according to treatment groups (supragingival control, supragingival control plus subgingival intervention on Day 0 and supragingival control on Day 0 and subgingival intervention 30 days later)

Click here to view


Changes in the GCF volume in microliters are shown in [Figure 2]. As can be seen, all groups had similar GCF volumes at baseline (GI: 0.39 ± 0.22 μl; GII: 0.42 ± 0.26 μl; GIII: 0.41 ± 0.14 μl). The GCF volume exhibited marked reductions over the first 60 days and continued to decrease thereafter. At Day 450, the GCF volume in GI was higher than that in other groups, but this difference was not significant.
Figure 2: Mean of gingival crevicular fluid volume (microliters) along the study period according to treatment groups

Click here to view


Even considering only the BOP + sites along the study [Table 3], no significant difference between groups regarding the GCF volume were observed (P = 0.259).
Table 3: Gingival crevicular fluid volume means in μl (±standard deviation) and log10 transformation on sites that bled on probing (n) along time according to treatment groups (supragingival control, supragingival control plus subgingival intervention on Day 0 and supragingival control on Day 0 and subgingival intervention 30 days later)

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   Discussion Top


This study evaluated changes in the GCF volume immediately after various non-surgical therapies and over the subsequent year with periodontal maintenance. The results demonstrated that the GCF volume decreased in all quadrants irrespective of whether only Supra or a combination of Supra with SRP intervention was used. Furthermore, this decrease was similar among groups and was maintained over time.

The present study used a split-mouth design, which has the advantage of using the participants as their own controls. Nonetheless, even with this experimental design, it is important to assure that the units that are allocated to different treatments at the start of the investigation are similar.[23],[27] This was demonstrated in the present study by the absence of differences in the mean GCF volume among groups at baseline.

The GCF volume reflects the clinical condition of the periodontium.[1],[5],[7],[28] Although there is no exact threshold for identifying healthy or diseased conditions, a reduction in GCF volume can be an important indicator of improvements in the periodontal status, especially those sub-clinical changes.

Traditionally, the GCF volume has been measured using different methods,[29] among which the Periotrom®/Periopaper® system is particularly prominent, although alternative approaches have also been proposed.[1] In the present study, the GCF volume was calculated using the methodology proposed by Alencar et al.,[24] whereby absorbent PS that were similar to Periopaper® in weight, width, length, and thickness[26] were used. The extent of absorption was initially measured in millimeters and then converted into Periotrom® units[24] followed by microliters, in a similar manner to the method used in the Periotrom®/Periopaper® system.

In the present study, it was found that all three groups exhibited a significant and similar reduction in GCF volume during the first 60 days of evaluation with 48.72%, 57.14%, and 46.34% reductions being observed for GI, GII, and GIII, respectively, at Day 60. These findings indicate that the subgingival instrumentation did not result in a greater reduction in GCF volume than Supra as a single intervention. Gomes et al.[19] also observed significant reductions in GCF volume after 30 days following a strict supragingival control protocol. Interestingly, the achieved results for both smokers and patients who had never smoked, respectively, 55.55% and 61.02% of reduction were greater than those observed by Qadri et al.[15] following the use of SRP (10%) or SRP plus neodymium: yttrium-aluminum-garnet (Nd:YAG) laser irradiation (27.8%). Similarly, Tüter et al.[16] reported a lower reduction in GCF volume of 26.09% with SRP and 21.28% with SRP plus the antibiotic doxycycline after 6 weeks, when compared with the present results.

No inter-group differences and no increase in GCF volume were observed between Days 60 and 270 for any of the groups. However, at Day 450, the GCF volume in GI (0.29 μl) trended to be greater than in GII and GIII (P > 0.05) and was above the threshold that is used to define the presence of “mild inflammation.” According to Griffiths (2003)[5] the threshold value range of 0.21 from 0.40 μl, or correspond to 20 μl/h or 0.40 μl according to Goodson (2003).[11] In this scenario, the results herein highlights the fact that supragingival biofilm control is not an appropriate treatment for destructive forms of periodontal disease but is important for achieving and maintaining subgingival stability. This contrasts with the clinical findings of Gomes et al.,[20] who did not detect any differences between groups at Day 450, corroborating that the measurement of GCF volume can be a more sensitive method to detect earlier inflammatory changes than other clinical indicators such as PD and BOP.[4],[5],[6],[11]

In the previous clinical investigation, Gomes et al.[20] observed a reduction in the number of BOP + sites during the course of therapy. In the present study, it was found that those sites that remained BOP + throughout the study also demonstrated no difference in GCF volume, irrespective of the type of therapy administered. This finding is important, as it demonstrates that supragingival biofilm control cannot only reduce the number of sites with periodontal inflammation but also maintains the stability of GCF volume in those sites that remain BOP + in the same way as is observed in groups with subgingival biofilm removal (GII and GIII).


   Conclusions Top


All protocols resulted in reductions in the GCF volume during the course of the study. Consequently, supragingival biofilm control can be considered an important tool for the clinician to improve the periodontal condition and to maintain the treatment results through time.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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Correspondence Address:
Dr. Patricia Daniela Melchiors Angst
Rua Ramiro Barcelos, 2492, Bairro Santana 90035-003, Porto Alegre, Rio Grade do Sul
Brazil
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijdr.IJDR_148_16

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