Effect of combination of ethylenediaminetetraacetic acid + tetracycline with coronally positioned flap in the treatment of gingival recession: A clinical study.

CONTEXT: Gingival recession is the apical migration of gingival margin results from destruction of the connective tissue leading to various esthetic problems. Many surgical procedures have been attempted to achieve root coverage that include free gingival grafts, pedicle flaps such as semilunar coronally repositioned flaps (SCRFs) and guided tissue regeneration. The exposed root surface has undergone substantial alterations and may no longer serve as an appropriate substrate for cell attachment and fiber development. When the denuded root surfaces are treated with biomodifiers following mechanical instrumentation, the resulting surface favors both the attachment of fibroblasts and new connective tissue attachment. It was then necessary to evaluate the surface characteristics of the acid demineralized root surface and its effect on periodontal wound healing. AIM: To evaluate the effect of the combination of ethylenediaminetetraacetic acid (EDTA) and tetracycline as root bio-modifiers along with SCRF for root coverage. SETTINGS AND
DESIGN: Twenty subjects were randomly assigned into two groups as cases (SCRF + EDTA + tetracycline [TTC]) and controls (SCRF).
MATERIALS AND METHODS: Twenty-four percentage EDTA and 100 mg/ml TTC hydrochloride were used along with semilunar coronally positioned flap. The clinical parameters such as recession height, the width of keratinized tissue, recession width, clinical attachment level, probing depth, plaque index, and gingival index were recorded at baseline, 1 and 3 months. STATISTICAL ANALYSES USED: The clinical parameters were compared using post-hoc test and the comparison between cases and controls was done using Mann-Whitney U-test.
RESULTS: No statistical significant difference has been observed between the groups.
CONCLUSION: It was concluded that no clinical benefit was observed after the application of a combination of 100 mg/ml TTC hydrochloride and 24% EDTA on the root surface.

INTRODUCTION

Gingival recession is defined as the location of the marginal tissue apical to the cementoenamel junction (CEJ). This condition may be associated with a periodontal disease or related to mechanical factors such as tooth brushing.[1] The treatment of buccal gingival recession is a common requirement due to esthetic concern or root sensitivity in patients with high standards of oral hygiene, prevention and management of root caries and cervical abrasions. Conventional scaling and root planning alone cannot totally eliminate the etiological contaminants, but does produce a surface smear layer that may inhibit cell migration and attachment. Later, studies by Urist publicized the effectiveness of acid demineralization as an adjunct to mechanical removal of calculus and cementum for periodontal reattachment.[2]

Since, then various etching agents such as citric acid,[2] ethylenediaminetetraacetic acid (EDTA),[1] tetracycline (TTC),[34] and phosphoric acid[2] have been used at different concentrations and time intervals to selectively modify the contaminated root surface by exposing collagen fibers and creating a hospitable substrate which favors the migration and attachment of fibroblasts.[3] However, Mariotti[5] in a meta-analysis stated that the use and application of citric acid, TTC or EDTA to modify the root surface provides no clinical benefit to the patient with respect to reduction of probing depths (PDs) or gain in clinical attachment levels. In 2004, Maniscalco and Taylor.[6] have shown a significant reduction in the nanobacterial (NB) count and lipid profile by using combination of EDTA and TTC to treat the calcific atherosclerotic disease and the nanobacteria were found to be sensitive in vitro to TTC and its action is enhanced by EDTA dissolving NB apatitic protective coat.

Numerous surgical procedures have been attempted to achieve root coverage that include free gingival grafts, pedicle flaps such as semilunar coronally repositioned flaps (SCRFs) and guided tissue regeneration. The decision to use the SCRF technique as designed by Tarnow was because of its advantages such as it does not alter the adjacent papillae or vestibular depth and creates no tension on the flap and sutures are not needed. As the use of combination of EDTA and TTC as root surface modifiers was never attempted before the aim of the present study was to evaluate the efficacy of this combination along with SCRF in the treatment of gingival recession.

MATERIALS AND METHODS

The study was designed and conducted in the Department of Periodontology, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India, to evaluate the efficacy of EDTA + TTC in root biomodification along with SCRF. The institutional ethical board approval was obtained before commencement of the study. Power analysis indicated with a minimal sample size of 20 subjects (n = 10 in each group) would have 80% power to detect 1 mm difference in recession between the two groups. Intra-examiner reliability was observed to be kappa = 0.80.

Twenty subjects within age group of 22–59 years were randomly assigned into two groups as cases and controls and included in the study depending on following criteria.

Inclusion criteria

Recession of 2–3 mm in maxillary anterior and bicuspid teeth

PD (<3 mm)

Width of keratinized tissue (WKT) (≥2 mm)

Vital tooth

Absence of caries or restorations in the areas to be treated

Patients who are not under any medication.

Exclusion criteria

Smokers

Systemically compromised patients

Pregnant women

Lactating mothers.

Criteria for grouping

Case group

Ten subjects with recession were treated using SCRF with the application of root biomodification agents (EDTA + TTC).

Control group

Ten subjects with recession were treated using SCRF without the application of root biomodification agents (EDTA + TTC).

Tetracycline

One hundred milligrams/milliliters (pH – 2.05) of fresh TTC solution was prepared by mixing 500 mg of TTC capsules in 5 ml of distilled water and stirred with a glass rod until the powder is dissolved.

Ethylenediaminetetraacetic acid

Twenty-four percentage EDTA solution was prepared by adding 24 g of powder in 100 ml of distilled water and is stirred with a glass rod, and pH is adjusted to 8.05.

CLINICAL PARAMETERS

An acrylic stent was prepared separately for each subject to standardize the measurement of clinical parameters at different intervals.

The clinical parameters recorded include:

Recession height (RH)

WKT

Recession width (RW)

PD

Clinical attachment level measurement

Plaque index (Silness and Loe, 1964)

Gingival index (Loe and Silness, 1963).

Initial therapy

The subjects were undergone initial phase I therapy, and the Fremitus test was performed to evaluate the traumatic occlusion. If the test was positive, occlusal adjustments were made. All subjects were instructed to perform Stillman's brushing technique using a soft toothbrush.

Surgical procedure

Surgical procedure was performed by single operator. Before surgery, extra-oral disinfection was performed with betadine and spirit and intra-oral asepsis with 0.2% chlorhexidine rinse. Lignocaine (2.0%) with 1:80,000 epinephrine was used as an anesthetic. Following anesthesia, bone sounding was done to know the level of the alveolar crest to determine the placement of incision. The exposed root surfaces were planned with curettes to remove the dental plaque and altered cementum [Figures 1–8].

Figure 1

Preoperative view of control subject

Figure 8

Postoperative view (after 3 months)

Measurement of recession height using acrylic stent and periodontal probe

Preoperative view of case subject

In the case group, the exposed root surfaces were conditioned with 24% EDTA for 3 min using a cotton pellet [Figure 6] in an active motion followed by irrigation with saline for 60 s. Later the root surfaces were conditioned with 100 mg/ml TTC solution for 3 min using a cotton pellet [Figure 7] in an active motion followed by 60 s irrigation with saline. The time calculation was done using a stopwatch.

Figure 6

Application of 24% ethylenediaminetetraacetic acid

Figure 7

Application of 100 mg/ml tetracycline hydrochloride

All the recession defects were covered using SCRF [Figure 3]. A semilunar incision was made extending from the mesial papilla to the distal papilla of the tooth with recession following the curvature of the receded gingival margin. A sulcular partial thickness incision was made with 15C BP blade until it reached the semilunar incision. Once complete flap reached the semilunar incision, it can be advanced as coronally as possible, without tension on the flap and positioned at the level of CEJ [Figure 3]. A moist gauze pad was placed with light pressure perpendicular to the flap at its new level for 10 min. Periodontal dressing was applied to the surgical area.

Figure 3

Coronally displaced semilunar flap

Postsurgical care

Subjects were instructed to take the analgesic medication only if they experienced pain. Subjects were enrolled in a periodontal maintenance program. Subjects were recalled after 10 days for the removal of periodontal dressing. All subjects were instructed to discontinue tooth brushing around the surgical site for first 30 days after surgery.

During this period, subjects were asked to maintain the oral hygiene measures by rinsing with a 0.2% chlorhexidine gluconate solution twice daily. After this period, subjects were instructed to use charter's brushing technique using a soft toothbrush.

All the subjects were recalled after 1-month and 3 months postsurgically to reevaluate the clinical parameters. All the recordings were subjected for statistical analysis using following formulae.

Statistical analyses

The analysis included descriptive statistics, the various clinical parameters were compared using post-hoc test and the comparison between cases and controls was done using Mann–Whitney U-test. P <0.05 was considered statistically significant.

RESULTS

All the parameters within the groups showed statistically significant improvement from baseline to 1-month and baseline to 3 months but no significance was observed between 1 and 3 months as shown in Tables 1 and 2. Whereas the parameters between case and control groups showed no statistical difference at baseline, 1-month and 3 months except for the baseline value of WKT [Table 3].

Table 1

Mean and SD of various parameters in control group

Table 2

Mean and SD of various parameters in case group

Table 3

Comparison of various parameters in between the groups

DISCUSSION

The main goal of periodontal therapy is to improve the periodontal health and thereby maintaining patient's functional dentition.[7] Scaling and root planning can reduce the periodontal pathogens as well as cytotoxic substances, present on the root surface of periodontally diseased teeth. However, these procedures inevitably leave a smear layer, which may influence periodontal tissue cells and inhibit new attachment. Therefore, the choice of root biomodification agents that ensure smear layer removal was critical for the successful outcome of periodontal therapy.[89]

The present study was conducted with an objective of evaluating the clinical efficacy of the combination of TTC and EDTA for root biomodification along with SCRF for the root coverage of ≥ 3 mm of gingival recession. In a study done by Bittencourt et al.[11] showed that the SCRF can be successfully used to treat Class I gingival recession with 91% root coverage and 53% complete root coverage.

In the present study, a significant reduction in RH was observed. Even though recession reduction was seen in both groups, better coverage was seen in the control group (P = 0.001). This may be attributed to the use of SCRF which is a sensitive technique, and its outcome depends on clot formation and stabilization.[1121314] In the case group, the application of EDTA, which is a chelator with anticoagulant activity[15] might have retarded coagulation events because of its possible incomplete removal from the root surface.[1]

Studies were done by Trombelli et al.[16] Pini Prato et al.[17] have shown that a less favorable treatment outcome was observed in wide (>3 mm) and deep (≥5 mm) recession defects. Preoperative recession depth, the position of the gingival margin at the end of the surgery and the horizontal component of the recession defect which were considered as important factors in achieving complete root coverage.[1218] Furthermore, the coronal displacement of the flap requires its relaxation and a passive adaptation without tension over CEJ for successful coverage.[19]

In the present study, RW was measured at CEJ and at the apex that showed a significant decrease in both the groups. RW >3 mm was considered less favorable for root coverage.[12]

Another factor for complete root coverage was the availability of thick gingiva in the recipient site as it harbors more patent vessels and eases surgical manipulation.[13] According to Baldi et al.[20] thick tissues could have a better chance of withstanding trauma and tension when compared to thin tissues. Tissue thickness of 0.8 mm is considered essential for complete root coverage.[19] Because, the amount of microvasculature is likely higher in thicker flaps when compared to thinner ones, which should increase the chance of flap survival.[1220]

At 3 months post-surgery, the WKT was increased in both the groups. The granulation tissue that fills the semilunar area converts the same type of tissue that was present prior to the surgery; this explains the increase in WKT in the control group. This is in accordance with Bittencourt et al.[11]

In the case group, the combination of TTC and EDTA have acted not only as an antimicrobial agent, but also a root conditioning agent, which may favor the root surface biocompatibility,[21] new attachment of connective tissue and thus increase the WKT.

The improvement of clinical attachment level was seen in both groups. The presence of collagen substrate subsequent to acid demineralization of the dentin surface could influence the wound healing response and serve to enhance chemotaxis, migration and attachment of the cells necessary for connective tissue regeneration.[2]

In the present study, the PD was reduced in both the groups. These improvements might simply reflect a change in the composition of periodontal tissues, rather than a true gain of new attachment. Improved gingival health may have contributed to the observed reduction of PD presumably by decreasing the edematous swelling of the marginal gingiva and/or by decreasing the penetrability of tissue by the probe as a result of an increase of collagen.[21]

In our study, the plaque index scores were significantly reduced in both the groups. However, the patient maintenance is better in the control group because some patients complained of sensitivity in the case group which could have impaired their oral hygiene maintenance. The improvement in the case group could be due to the antimicrobial and bacteriostatic activity of TTC. This is in consistent with the study done by Raad et al.[15] who showed that the activity of the combination of minocycline and EDTA in a suspension was shown to be synergic against Gram-negative bacilli.

The combination the minocycline and EDTA is not inhibited by the extracellular slime but has been shown to disrupt the slimy biofilm layer. The mechanism of action of EDTA in inhibiting biofilms formation is possibly through its chelating activity on calcium, which is a component essential to the maintenance of the extracellular biofilm matrix.[15]

The gingival index scores were reduced in both the groups. This could be due to scaling and root planning performed in both groups and an additive factor of antimicrobial effect of TTC in the case group.[22] It has been shown that the combination of TTC and EDTA had significantly reduced the NB count in calcific atherosclerotic disease and also effective in preventing catheter-related colonization, bacteremia, septic phlebitis, and endocarditis.[615]

CONCLUSION

In consideration of the improvement of clinical parameters, we used a combination therapy of TTC and EDTA in the hope of an additive or synergistic effect of the two agents, but it seemed to fall short of expectation. We were able to observe that a combination therapy has more demineralizing potential than individual agents in vitro. It was concluded that no clinical benefit on the treatment of gingival recession after the application of a combination of 100 mg/ml TTC hydrochloride and 24% EDTA on the root surface along with SCRF.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.