|One-stage full-mouth disinfection combined with a periodontal dressing: a randomized controlled clinical trial
For figures, tables and references we refer the reader to the original paper.
Periodontitis is an inflammatory disease that results in the destruction of the teeth-supporting tissues. It is a result of an imbalance between the wide range of microorganisms, the host response and some essential modifying factors (Socransky & Haffajee 1992). The primary clinical signs are bleeding on probing (BOP), pocket formation (PPD), gingival recession (REC) and at a later stage increased tooth mobility. The goals of treatment are to reduce the infection, resolve inflammation and create a clinical condition, which is compatible with periodontal health (Lang & Tonetti 2003).
It has been shown that non-surgical periodontal therapy, consisting of scaling and root planing, results in clinical improvements (Badersten et al. 1981). This is usually done in a quadrant wise approach (QSRP). In 1995 Quirynen and co-workers introduced the one-stage full-mouth disinfection (OSFMD). With this procedure scaling and root planing was performed in two sessions within 24 h and was supplemented with supra- and subgingival use of chlorhexidine (Quirynen et al. 1995, 2006, Mongardini et al. 1999).
Periodontal dressings were introduced in 1923 in order to protect wounds after periodontal surgery (Ward 1923). Nowadays, it is still used after resective periodontal surgery as well as after recession coverage. The periodontal dressing protects the tissue and keeps the tissue in close contact with the teeth. It stabilizes the coagulum and protects it from different forces during talking and eating (Wikesjö et al. 1992).
Wound healing is a complex process involving different phases such as; homeostasis phase, inflammatory phase, proliferation and remodelling phase (Stadelmann et al. 1998). The first and most important step is the formation of a fibrin clot. This clot will protect the wound and attract inflammatory cells. When a tissue is wounded, platelets start to release inflammatory factors, cytokines and growth factors to facilitate the healing (Barrientos et al. 2008). When all the steps are successfully accomplished, the healing will result in reduction of the swelling, recession of the gingival margin due to resolution of inflammation and formation of long junctional epithelium.
Sigusch et al. (2005) introduced the use of a periodontal dressing as an adjunctive tool for the treatment of patients with aggressive periodontitis. The group with the periodontal dressing applied for 7 days showed a significant pocket reduction and clinical attachment gain compared with the control group. Genovesi et al. (2012) applied a periodontal dressing for 7 days after non-surgical therapy for the treatment of patients with moderate-to-advanced periodontitis. The results were similar to the results of Sigusch et al. (2005).
The aim of this randomized clinical trial was to evaluate, in a split-mouth design, the effect of a periodontal dressing applied for 7 days after OSFMD.
Material and Methods
This study was designed as a randomized-controlled split-mouth trial to compare the clinical effects of two different periodontal treatments, OSFMD alone or combined with a periodontal dressing for 7 days with a 3 months follow-up period. The ethical committee at the University Hospital Leuven approved the protocol. All participants had to sign an informed consent before entering the study. The study started in September 2010 and ended in June 2012.
Twenty-six volunteers were selected for this prospective study (Fig. 1). All patients consulted or were referred to the Department of Periodontology of the University Hospitals Leuven for the treatment of chronic periodontitis. The general health of all the patients was good. The following inclusion/exclusion criteria had to be fulfilled:
Age between 30 and 75 years.
A minimum of 18 teeth, wisdom teeth excluded.
Previously untreated moderate chronic periodontitis (Armitage 1999) with radiographic evidence of generalized alveolar bone loss >30%.
Presence of at least one pocket with probing pocket depth (PPD) ≥6 mm per quadrant, which was BOP.
Presence of at least three teeth per quadrant.
Periodontal treatment in the last 3 years.
Antibiotic intake 6 months before the screening visit.
Systemic diseases with an impact on periodontal healing (e.g. Diabetes).
The purpose of the study was explained to the patients who met the inclusion criteria and they were asked to participate by signing an informed consent form. The following clinical parameters (in sequential order) were recorded by only one trained and calibrated periodontist (J.K.).
The plaque score (PS) was detected visually or with the probe at 4 sites per tooth (mesial, distal, buccal and lingual); the scores ranged from 0 (absent) to 1 (present) (O'Leary et al. 1972).
The PPD was recorded to the nearest 0.5 mm at six sites per single-rooted teeth and ten sites for multi-rooted teeth.
The amount of gingival recession (REC, the distance from the cemento-enamel junction to the gingival margin) was measured to the nearest 0.5 mm at the same sites as the PPD.
The BOP was evaluated 30 s after probing in the depth of the pockets at four sites per tooth (mesial, distal, buccal and lingual); the scores ranged from 0 (absent) to 1 (present).
The clinical attachment level (CAL) was calculated for each site as the sum of the PPD and the REC.
These variables were recorded using the Merritt B probe (Hu-Friedy, Chicago, IL, USA).
After the clinical examination, oral hygiene instructions were given (the modified-Bass technique, inter-dental cleaning and tongue scraping in the case of tongue coating). After 1 or 2 weeks OSFMD was performed by one periodontist (J.K.). Scaling and root planing using ultrasonic and hand instruments was performed in two sessions within 24 h and was supplemented with:
Tongue brushing (by the patient) for 60 s with chlorhexidine 1% gel.
Rinsing twice with a chlorhexidine 0.12% solution for 1 min.
Spraying the pharynx with a 0.12% chlorhexidine spray.
Subgingival irrigation of all the pockets three times within 10 min. with the chlorhexidine 1% gel using a syringe (the tip of the needle was blunted so that the resistance offered by the bottom of the pocket could be felt).
Additionally, the patients had to rinse twice daily for 1 min. with a 0.12% chlorhexidine solution for 2 months (Quirynen et al. 1995, 2006, Mongardini et al. 1999).
The first treatment was started at the right side (first and fourth quadrant). At the end of the first treatment, a test and control side was selected by means of a computer-generated randomization list. If the first quadrant was selected as the test side, the third quadrant was selected after the second treatment as the test side. Hereby, the periodontal dressing was always placed in one upper and one lower quadrant. The operator (J.K.) mixed the periodontal dressing (Coepak®, Alsip, IL, USA) according to the manufacturer's instructions. The oral hygiene instructions were given and each patient had to avoid brushing the periodontal dressing area as long as the periodontal dressing was in place.
After 1 week, the periodontal dressing was removed from the test sides and oral hygiene instructions were repeated, identical to the first time. The patients had to compare the difference between the sides with the periodontal dressing and the sides without the periodontal dressing. During this appointment the patients had to fill out a pain intensity scale on a scale from 0 to 10 (0 = no pain, 5 = moderate pain and 10 = worst imaginable pain) and the amount of pain medication was recorded. After 3 months, all clinical examinations were recorded by only one trained and calibrated periodontist (J.K.).
A power analysis was carried out. Based on these calculations, it was defined that 22 patients would be necessary. Considering a drop out of about 15%, it was established that at least 25 patients were needed. The concordance correlation coefficient was used to quantify the degree of agreement or congruence between two measurements. Linear mixed models were fit to assess the difference between the two treatments. Treatment was used as a fixed factor. Position, tooth number and patient were used as nested random factors. Normal quantile plots and residual dot plots were used to assess the normality and variability distribution of the data and did not indicate any deviation from the basic assumptions. Significance was determined by using an α of 0.05; p-values lower than 0.05 were considered significant. S-Plus 7 (Tibco, Palo Alto, CA, USA) was used for the statistical analyses.
Twenty-six patients passed the inclusion / exclusion criteria. Two patients were excluded because they did not show up at the final appointment after 3 months. Finally, a total of twenty-four patients were statistically analysed. Table 1 presents the demographic characteristics. All patients belonged to the Caucasian race with an average age of 48.3 (range 33–64 years). The total number of teeth and mean percentage of sites (with PPD < 4 mm, PPD 4–6 mm and PPD > 6 mm) were equally distributed.
Table 1. Demographic characteristics and mean ± SD full-mouth clinical parameters
The mean values for PS and BOP are presented in Table 2. The control group showed a significant reduction of the PS with 37% (p = 0.0001) and BOP with 39% (p = 0.0001) compared to the baseline. The test group also showed a significant reduction of the PS with 48% (p = 0.0001) and BOP with 51% (p = 0.0001) compared to the baseline. The test group showed a significantly higher reduction of the PS with 11% (p < 0.0001) and BOP with 12% (p < 0.0001).
Table 2. Outcome variables for single and multi-rooted teeth together
The pain sensation was measured 7 days after OSFMD, the results are presented in Table 2. When compared with the control group the test group showed a significant reduction of the pain intensity, which was 1.71 (p < 0.0001).
The mean values for PPD, REC and CAL are presented in Table 2. The control group showed a significant reduction of the PPD with 1.20 mm (p = 0.0001) and CAL with 0.74 mm (p = 0.0001) compared to the baseline. The test group also showed a significant reduction of the PPD with 1.49 mm (p = 0.0001) and CAL with 1.01 mm (p = 0.0001) compared to the baseline. The test group showed a significantly higher reduction of the PPD with 0.29 (p < 0.0001) mm and CAL with 0.26 mm (p < 0.0001). The control group showed a significant increase of the REC with 0.45 mm (p = 0.0001) compared to the baseline. The test group also showed a significant increase of the REC with 0.48 mm (p = 0.0001) compared to the baseline. The test group showed no significant difference of the REC. Those three clinical parameters were also divided into moderate pockets (4–6 mm) and deep pockets (>6 mm). The control group showed a significant reduction of the PPD of the moderate pockets with 1.87 mm (p = 0.0018) and for the deep pockets 3.27 mm (p = 0.0018). The significant reduction was also seen for the CAL of the moderate pockets with 1.20 mm (p = 0.0018) and for the deep pockets 1.83 mm (p = 0.0018) compared to the baseline. The test group also showed a significant reduction of the PPD of the moderate pockets with 2.20 mm (p = 0.0018) and for the deep pockets 3.56 mm (p = 0.0018). Again the significant reduction was also seen for the CAL of the moderate pockets with 1.53 mm (p = 0.0018) and for the deep pockets 2.10 mm (p = 0.0018) compared to the baseline. The test group showed a significantly higher reduction of the PPD of the moderate pockets with 0.32 mm (p < 0.0001) and for the CAL of the moderate pockets 0.33 mm (p < 0.0001). The deep pockets of the test group showed no significantly higher reduction of the PPD with 0.30 mm and for the CAL 0.27 mm compared with the control group. The control group showed a significant increase of the REC of the moderate pockets with 0.67 mm (p = 0.0018) and for the deep pockets 1.43 mm (p = 0.0018) compared to the baseline. The test group also showed a significant increase of the REC of the moderate pockets with 0.66 mm (p = 0.0018) and for the deep pockets 1.44 mm (p = 0.0018) compared to the baseline. The test group showed no significant difference of the REC of moderate pockets or deep pockets. Additionally the outcome variables for single-rooted teeth (Table S1) and for multi-rooted teeth (Table S2) are available online.
The data for the residual sites at subject level are presented in Table 3. It presents numbers and percentage of subjects exhibiting different thresholds of residual sites with PPD ≥5 mm according to the individual risk profile for periodontal disease progression introduced by Lang & Tonetti (2003). The test group showed fewer subjects (n = 3) for high risk of disease progression (≥9 with PPD ≥5 mm), in comparison with the control group (n = 9). Conversely, the test group showed more subjects (n = 16) for low risk of disease progression (1–4 sites with PPD ≥5 mm), in comparison with the control group (n = 10).
Table 3. Number and percentage of subjects presenting low [1–4 sites with probing pocket depth (PPD) ≥5 mm], moderate risk (5–8 sites with PPD ≥5 mm) or high (≥9 sites with PPD ≥5 mm) risk for disease progression according to Lang & Tonetti (2003)
Table 4 presents the mean percentage of sites with PPD ≥5 mm, PPD ≥6 mm and PPD ≥7 mm after 3 months. The test group had significant less percentage of sites with PPD ≥5 mm (2.7% versus 4.8%, p < 0.0001), PPD ≥6 mm (0.7% versus 1.2%, p = 0.0066) and PPD ≥7 mm (0.2% versus 0.4%, p = 0.0333) compared with control group.
Table 4. Mean number (mean percentage) ± SD of sites with probing pocket depth (PPD) ≥5 mm, as well as sites with PPD ≥6 mm and ≥7 mm at 3 months
This randomized controlled clinical trial demonstrated that the application of a periodontal dressing after OSFMD for 7 days resulted in significant clinical improvements compared to OSFMD without periodontal dressing.
For the teeth with moderate pockets the results with the periodontal dressing group showed a significant additional pocket depth reduction and a clinical additional attachment gain compared to OSFMD. In contrast, the results for the teeth with deep pockets showed no significant additional pocket depth reduction nor additional clinical attachment gain although there could be a tendency that this effect occur. These non-significant results could be explained because there were not enough deep pockets present in the study population. Hung had systematically assessed the effect of non-surgical therapy. The periodontal dressing group showed higher results compared to the systematic review (Hung & Douglass 2002). For the moderate pockets the results showed a pocket depth reduction of 1.02 mm versus 2.20 mm and a clinical attachment gain of 0.53 mm versus 1.53 mm. The deep pockets showed a pocket depth reduction of 1.98 mm versus 3.56 mm and a clinical attachment gain of 1.14 mm versus 2.10 mm.
The same results were seen for the single and multi-rooted teeth. For the teeth with moderate pockets the results with the periodontal dressing group showed a significant additional pocket depth reduction and a significant additional clinical attachment gain compared to OSFMD. In contrast the results for the teeth with deep pockets showed no significant additional pocket depth reduction nor additional clinical attachment gain albeit there could be a tendency that this effect occur. These non-significant results could be explained because there were not enough deep pockets present in the study population.
Residual pockets are important to evaluate the success of the periodontal treatment or to decide if additional periodontal surgery is needed. Mostly, when residual pockets of 5 mm or higher are present after non-surgical therapy, periodontal surgery may be necessary. The periodontal dressing group showed a significant lower percentage of sites with PPD ≥5 mm compared with the control group. Less sites of the periodontal dressing group could needed periodontal surgery.
The presence of residual pockets (≥5 mm) after periodontal surgery is one of the most important risk indicator for recurrence of periodontitis in maintenance patients (Lang & Tonetti 2003). The periodontal dressing group presented significant lower mean number/percentage of the low risk group (1–4 sites with PPD ≥ 5 mm) after 3 months compared with the control group. The control group was able to bring 41.7% patients to a low risk profile and the periodontal dressing group was able to bring 66.7% patients to a low risk profile.
The present analysis showed the additional benefit of using a periodontal dressing combined with OSFMD in a short-term basis. The periodontal dressing might well accelerate the healing instead of improving it. This additional result could be disappearing in a few months or stay stable over time. Sigusch et al. (2005) showed that the result of the periodontal dressing group remained stable in the next 24 months.
A potential limitation of the present analysis is the lack of blindness since operator and examiner were the same. This lack of blindness could possibly affect the final outcome. The examiner might have remembered which sides were treated with periodontal dressing. However, it is entirely possible that, over the course of 3 months, the examiner could have forgotten.
Pain is a common problem after non-surgical therapy. Pain varies over time. It is not felt in a constant intensity (Boormans et al. 2009). It is thus difficult for patients to summarize their differing pain levels with a single number. This is a disadvantage when using the numeric rating scale (Kahneman et al. 1993). The control group showed a 5.1 on the pain intensity scale, according to the numeric rating scale moderate pain. The periodontal dressing group had 3.4 on the pain intensity scale which is mild pain. This was significantly lower than the control group. Is this clinically relevant compared to the possible side effects? In the beginning, chewing and speaking are difficult. If the periodontal dressing is placed with great pressure it could cause impaired healing or swelling. After several days, it could create an unpleasant taste, odour and colour. It is very important that the patient is well informed about the usage of periodontal dressing.
The amount of plaque is critical for the success of periodontal treatment. A PS of less than 11% for the periodontal dressing sides could be the cause because of the additional results. A level of plaque has not yet been established that results in periodontal health. A full-mouth PS of 20–40% might be tolerable by most patients. (Axelsson et al. 2004) It is important to realize that the PS has to be related to the host response (Van Dyke & Serhan 2003). In a split-mouth design it would be expected that the oral hygiene would be the same but it was interesting to see that the PS differs between test en control sides. The lower PS could be the explanation for the additional result on the periodontal dressing sides but it does not explain why there is less plaque present.
When the gingiva is damaged after non-surgical therapy wounds can form. Healing after non-surgical therapy occurs because existing tissues repair themselves. In a couple of seconds the homeostasis process starts, forming a blood clot. The blood clot has three main functions: protection denuded tissue, provisional matrix for cell migration and reservoir of growth factors and cytokines (Stadelmann et al. 1998). During this coagulation process, some products act as chemotactic agents attracting phagocytic cells to the inflammation side. The platelets produce some proteins that could be antimicrobial, for example, beta-lysine which causes lysis of Gram-positive bacteria (Yeaman 2010). The platelets also produce growth factors and cytokines that stimulate the wound healing (Barrientos et al. 2008). When all the steps are successfully accomplished, the healing will result in reduction of the swelling, recession of the gingival margin due to resolution of inflammation and formation of long junctional epithelium. The saliva and the movements of the cheeks are probably the main cause that only a small portion of the blood remains present. When the periodontal dressing is applied at the wound, the blood clot is more protected, the gingiva is more stabilized, more portion of the blood clot might be present and the gingiva will adhere more closely to the tooth. This may be the reason for the better clinical outcomes and the reduction of pain after non-surgical therapy.
A few studies have investigated the possible antimicrobial effect of the periodontal dressing (O'Neil 1975, Haugen et al. 1977, Cheshire et al. 1996). The periodontal dressing that was used consisted of zinc oxide non-eugenol. The reaction is based on a metallic oxide and fatty acids. According to the information from the manufacturer two possible anti-infective ingredients were visible, lorothidol (fungicide) and chlorothymol (antibacterial). No anti-inflammatory ingredients were observed. So far, there is no study available that can actually prove whether these ingredients have an effect on the plaque accumulation. O'Neil stated in 1975 that the use of an antimicrobial agent is not necessary in the periodontal dressing because it forms a physical barrier to saliva, bacterial contamination and food impaction. Further research is needed to prove if periodontal dressing has some anti-infective effect.
Our data are in agreement with two other studies. Sigusch et al. (2005) introduced the use of a periodontal dressing as an adjunctive tool in the treatment of patients with aggressive periodontitis. The patients were treated with non-surgical therapy, systemic antibiotics (Metronidazole 500 mg b.i.d. for 8 days) and periodontal dressing. Three treatment groups were used; in group 1 the periodontal dressing was removed after 3–4 days, in group 2 the periodontal dressing was removed after 7–8 days and the control group. The non-surgical therapy consisted of two parts, part one scaling and root planing in 3–4 sessions and part two manual root curettage in one session. The usage of chlorhexidine was not mentioned. After 6 months group 1 showed an additional pocket depth reduction of 0.7 mm and also an additional probing attachment gain of 0.7 mm compared with the control group. Group 2 showed an additional pocket depth reduction of 1.8 mm and also an additional probing attachment gain of 1.8 mm. Genovesi et al. (2012) used a periodontal dressing for 7 days during the non-surgical treatment of patients with moderate-to-advanced periodontitis in a split-mouth design. The patients were treated with a full-mouth scaling and root planing within 24 h and this was followed by curettage of the epithelium. Also here, the usage of chlorhexidine was again not mentioned. After 2 months, the periodontal dressing group showed an additional pocket depth reduction of 0.8 mm compared with the control group. The additional probing attachment gain for the periodontal dressing group was 1.1 mm compared with the control group.
The results of this randomized clinical trial show the additional effects that a periodontal dressing has when it is combined with OSFMD. The additional effects of the periodontal dressing could be explained by: protection of the wound, stabilization of the tissues, availability of the blood clot and maybe some antimicrobial effects of the periodontal dressing. Within the limitations of this study a periodontal dressing has additional benefits that are statistically significant for the moderate pockets. It is important to mention that periodontal dressing causes less pain after OSFMD. To reduce the pain a periodontal dressing could be a good alternative to pain medication. Further randomized clinical trials are necessary to confirm this result and this should be done with more patients involved, as this may lead to a significant effect in the deep pockets as well.
Scientific rationale for the study: Previous studies have suggested that scaling and root planing combined with a periodontal dressing applied for 7 days might have some beneficial effects for the treatment of periodontitis. However, more studies are needed to verify this.
Principal findings: Periodontal dressing applied after OSFMD showed significant superior results in all clinical parameters compared to OSFMD alone after 3 months. The results included a significant reduction of pain after OSFMD and reducing the residual pockets up to 3 months post-treatment.
Practical implications: Periodontal dressing applied after OSFMD can reduce the pain after OSFMD and offers a clinical benefit for the treatment of patients with chronic periodontitis.