A Randomized Controlled Trial on a Minimally Invasive Microsurgical Versus Conventional Procedure for the Management of Localized Gingival Recession in Esthetic Zone using Alloderm.

BACKGROUND: Microsurgical technique is a recent advancement in periodontal plastic surgery, which improves the predictability of periodontal procedures, providing better esthetic results with minimal postoperative discomfort. Alloderm is an alternate to connective tissue grafts, which has been successfully used for root coverage. The present study aims at Comparative assessment of Micro and Conventional surgical techniques for root coverage using coronally positioned flap (CPF) with Alloderm.
MATERIALS AND METHODS: Twenty sites with Miller's Class I or II gingival recession defects were selected; sites were randomly divided into control and test groups. Test sites were treated with CPF and acellular dermal matrix (ADM) using Microsurgery and control sites were treated with CPF and ADM using conventional method.
RESULTS: Conventional and Microsurgical procedures for root coverage showed a statistically significant difference in all clinical parameters from baseline to 3 and 6 months (P < 0.01). The microsurgical technique demonstrated a significant difference in ultrasonographic thickness of gingiva (P < 0.003) and patient satisfaction score (P < 0.005).
CONCLUSION: Microsurgical procedure for root coverage was found to be superior to the conventional macrosurgical approach under magnification. Microsurgical sites healed faster with neovascularization demonstrated on ultrasonographic evaluation with improved gingival thickness and patient satisfaction scores. Copyright:

INTRODUCTION

Surgical coverage of recession has mainly become an esthetic rather than a functional demand. Along with esthetic deficiency, the exposed root surface poses other problems such as Hypersensitivity and root caries.[1]

Various surgical approaches have been mentioned for root coverage, i.e., laterally displaced flaps, coronally positioned flap (CPF) with or without the use of connective tissue grafts and other combination techniques.[12] Connective tissue graft is considered the gold standard because of its high predictability and it increases the width and thickness of keratinized tissue.[2] But it requires a second surgical site to harvest and causes additional patient discomfort. Alloderm is a substitute for connective tissue graft and CPF with Alloderm is an effective and easier to perform for root coverage, without morbidity and complications associated with the donor-site surgery.[3]

Microsurgical procedures have achieved great success in periodontal plastic surgery. The use of microscope in periodontal practice has helped enhancing the esthetics. It improves the visibility, accessibility allowing delicate manipulation of flaps, thereby helping to gain primary wound closure. Therefore, a microsurgical procedure help optimizing the results.[3]

The thickness of the flap has also been an excellent predictor of complete root coverage and it has been seen that a thicker flap has greater vascularization at marginal gingiva, which increases the probability of complete root coverage.[5] Both invasive and noninvasive methods are available for the assessment of gingival thickness; one such noninvasive method is ultrasonography, which assesses the gingival thickness more accurately, rapidly, and atraumatically.[6]

The views of the patient and his experience from the recession coverage procedure also play an important role in the ultimate success of the treatment. With esthetic, now becoming an important parameter for any root coverage procedure, patient's satisfaction,[7] and their acceptance to the treatment provided shall also guide the operator for the choice of appropriate treatment modality.

The present study was undertaken to compare microsurgical and conventional surgical techniques for root coverage of localized gingival recession (GR) using CPF with Alloderm and also to compare the thickness of gingiva with ultrasonography for both the surgical techniques, along with the assessment of patient-centered parameters.

MATERIALS AND METHODS

Following approval from the Institutional Ethics Committee (SDCHREC), 30 Patients were selected. Both Male and Female (Males 25, Females 5) were included in the study. Inclusion criterion consisted of Presence of Millers Class I and II GR (≥2 mm) in maxillary or mandibular anterior teeth, nonsmoker, vital teeth, no past surgical treatment of the involved site and exclusion of patients were medically compromised patients, pregnant and lactating women, noncooperative patients, pathologic mobility, previous root coverage procedure at test or control sites, use of the fixed orthodontic or removable appliance, root caries, etc., radiographs were taken. A total of 20 recession areas were treated after signing the consent form.

After completion of phase 1 therapy, sites on the selected patients were randomly assigned to test group (n = 15 Microsurgery with CPF and Alloderm) or control group (n = 15 Macrosurgery with CPF and Alloderm).

All clinical parameters were recorded using U. N. C 15 Probe at Baseline, 3 and 6 Months. Height of GR: Distance between cementoenamel junction (CEJ) to the most apical area of the gingival margin (GM). Probing pocket depth: Distance between GMs to the base of the pocket. Clinical attachment level (CAL): From C. E. J to pocket/sulcus depth. The width of the Attached Gingiva (WAG) was measured by subtracting the probing depth (PD) from a distance between the GM up to the mucogingival junction (MGJ).

The gingival thickness was evaluated by ultrasonography. The thickness was measured at baseline, 3, and 6 months.

The selected site was subjected to ultrasonographic examination by Acuson X 300 of Siemens Medical System U. S. A [Figure 1]. The ultrasound transducer was covered with ultrasound gel (Viva gel, India) and positioned on the skin corresponding to the surgical site. Once the operated site was identified, longitudinal scans (sagittal plane) to define the gingival thickness were obtained. corresponding to the surgical site as shown in Figure 2, gingiva appeared hypo echoic and tooth surface appeared hyperechoic. Images were assessed thrice by the Ultrasonologist for calculating the average thickness of gingiva at the operated sites [Figure 3].

Figure 1

Ultrasound machine-Acuson X 300 of siemens medical system U. S. A

Figure 2

Placement of transducer over surgical site

Figure 3

Interpretation of ultrasound image

Patient satisfaction scores

At 10 days, 1 and 6 months postoperatively, Patient Satisfaction was recorded on a scale of 1–10 (1 = unsatisfied to 10 = fully satisfied). The satisfaction criterion included (1) Intra-operative experience at 10th Day: Pain during Surgery and discomfort experience related to the duration of procedure and handling by the operator (2) Postoperative Experience at 1 month: For Pain, Swelling and Postoperative Complications, (3) Hypersensitivity at 6 months, (4) Recession Coverage at 6 months, (5) Appearance (color and form) at 6 months.

The surgical procedure was performed by single experienced operator. Patients were asked to rinse with 10 ml of 0.2% chlorhexidine gluconate solution as a presurgical rinse. The extra oral surfaces of the patient were swabbed with Betadine (10% Providone Iodine). The operative site was anesthetized with 2% lignocaine Hcl with adrenaline (1:80,000) using block or infiltration technique. CPF surgery was performed by intra sulcular incision on the buccal aspect of the affected tooth. Two horizontal incisions were made at right angles to the adjacent interdental papillae at the CEJ level. The horizontal incisions were connected to divergent vertical releasing incision mesially and distally and a trapezoidal flap was elevated, extending apically, tension was released to favor the coronal positioning. The adjacent papillae were deepithelized. Root surface was thoroughly planed and rinsed with saline. CPF surgery was done for both Test (Microsurgery) and Control (Macrosurgery) group.

For control group (macrosurgery): CPF was done by using conventional surgical instruments (11 and 15 no B. P blade, Periosteal Elevator, Scissors). After reflection of flap, Alloderm was placed on the recession defect and stabilized with resorbable 5-0 Gut sutures, Flap was placed coronally such that it completely covers ADM and sutured by simple loop suturing technique using 3-0 silk suture. The periodontal dressing was applied on the surgical site [Figures 4 and 5].

Figure 4

Instrument tray for coventional surgery

Figure 5

Steps for conventional/macrosurgical surgical site

Test group microsurgery was performed by minimally invasive approach using microsurgical instruments and surgical operating microscope (three dimensional medical systems). All the incisions were given with microsurgical blade and flap was reflected by using micro-periosteal elevator. Flap was sutured with 7-0 silk sutures as shown in [Figures 6–8].

Figure 6

Operator working with surgical operating microscope

Figure 8

Microsurgical technique

Set of microsurgical instruments used for test sites

Post surgically Both Test and Control group patients were prescribed systemic antibiotics Amoxicillin 500 mg thrice a day for 5 days and combination of Brufen and Paracetamol (Ibugesic Plus) twice a day 5 days. Ten days following surgery, the dressing and sutures were removed and wound irrigated with normal saline. Patient satisfaction scores were recorded. Patients were recalled after 1, 3, and 6 months [Figure 9].

Figure 9

Comparative evaluation of results at baseline, 3 and 6 months for conventional/macrosurgical (control) and microsurgical (test) group

Quantitative data were recorded as mean and standard deviations, Kolmogorov and Smirnov test to verify the normality of the data were used. For intragroup comparison at baseline to 3 and 6 months, paired tests were applied. Significance of change was assessed using Wilcoxon signed-rank test for hazard risk (HR), probing depth PD, CAL, WKT, % recession coverage. The significance of difference was assessed using Mann–Whitney U-test for all the parameters.

RESULTS

Uneventful healing was observed for all the patients. There was a vast difference in the healing pattern in the releasing incision area and the merging of alloderm into host tissue was seen at a faster rate at microsurgical site as compared to macrosurgical approach. All the patients completed their follow-up recalls at 3 months and 6 months.

No statistically significant difference was found in HR, PD, CAL, WKT, % recession coverage at 6 months follow-up, the statistically significant difference was seen in the keratinized tissue thickness which was lower (P-value 0.001) and significant difference was observed in Patient satisfaction score showing a higher score for microsurgical (test group).

Statistically significant reduction was found in HR from baseline to 3 and 6 months in both the test and control group.

On comparison of ultrasonographic gingival thickness between the two groups, it was found to be statistically significant with the P value of 0.003 at 3 months and 0.001 at 6 months Baseline clinical parameters in Control & Test groups depicted in [Table 1 and Graph 1].

Table 1

Baseline clinical parameters in Control & Test groups

Parameter	Control Group (n=10)		Test Group (n=10)		Significance of difference between two groups (Mann-Whitney U test)
	Mean	SD	Mean	SD	Z	P
Length of recession (mm)	2.60	0.52	2.60	0.70	0.171	0.912
Probing pocket depth (mm)	1.25	0.72	1.05	0.76	0.643	0.579
Clinical attachment level (mm)	3.70	0.48	3.30	0.68	1.850	0.105
Width of attached gingival (mm)	1.30	0.48	1.10	0.57	0.801	0.529

Graph 1

Baseline clinical parameters in control and test groups

Significant root coverage was obtained at 6 months for both the test and control group [Tables 2–4].

Table 2

Summary of Clinical Findings at different time intervals of Control and Test groups

Parameter	Baseline		3 months		6 months
	Control	Test	Control	Test	Control	Test
Length of recession (mm)	2.60±0.52	2.60±0.70	0.20±0.42a	0.0±0.0a	0.50±0.53a	0.25±0.43a
Gingival Recession (%)	0.0±0.0	0.0±0.0	91.67±18.0a	100.0±0.0a	81.67±20.0a	89.17±20.0a
Probing pocket depth (mm)	1.25±0.72	1.05±0.76	0.30±0.48a	0.20±0.42a	0.60±0.52a	0.50±0.53a
Clinical attachment level (mm)	3.70±0.48	3.30±0.68	0.30±0.48a	0±0a	0.50±0.53a	0.30±0.48a
Width of attached gingival (mm)	1.30±0.48	1.10±0.57	2.40±0.52a	2.50±0.85a	2.20±0.42a	2.50±0.85a
USG thickness	1.06±0.14	1.10±0.17	1.600±0.094a	1.390±0.137a	1.490±0.074a	1.270±0.177a

Table 4

Comparison of mean difference in Ultrasonographic Gingival thickness of Control & Test groups at different time intervals

Time Interval	Control Group (n=10)		Test Group (n=10)		Significance of difference between two groups Mann Whitney U test)
	Mean	SD	Mean	SD	Z	P
Baseline	1.06	0.14	1.10	0.17	0.467	0.684
3 months	0.54	0.18	0.29	0.11	2.892	0.003
6 months	0.43	0.16	0.17	0.07	3.159	0.001

Patient satisfaction for all the parameters, the mean value of test group was higher than the control group, the difference between the groups was statistically significant for all parameters except for intraoperative satisfaction [Graph 2].

Graph 2

Control and test group comparison of patient satisfaction for different parameters of assessmen

DISCUSSION

GR is a common esthetic concern. Many therapies are directed at controlling the progression, enhancing the esthetics.[8]

The CPF is one of the popular surgical options for GR. It has many advantages over other techniques, provides a perfect color/contour match with the surrounding tissue, and simple to perform. The association of the CPF and acellular dermal matrix (ADM) is also considered predictable and acceptable root coverage is achieved.

ADM successfully covers GR.[9] Shulman was the first clinician to document ADM in dentistry.[10] ADM is available that retains the basement membrane and extracellular matrix of the dermis. It, therefore, encourages autogenous epithelial cells to attach and migrate over its surface. As a donor material, it eliminates the need for second surgical site.[9]

Microsurgical approach of CPF with ADM for root coverage is more predictable by enhancing visual acuity using the operating microscope and microsurgical instruments with minimal trauma. With primary wound closure and neovascularization, healing is faster.[3] reducing the resorption of the connective tissue graft, patient pain, and discomfort.[4]

Gingival thickness is important factor in the development of GR, wound healing, and flap management, also a significant predictor of root coverage. Eger, Muller, and Heinecke used ultrasonography for measuring the thickness of the attached gingiva and reported validity and reliability.[11]

In the present study, the mean reduction in PD was statistically significant For the control group, the mean difference of gain in the CAL from baseline to 3 months and 6 months post-surgery was 3.40 ± 0.52 and 3.20 ± 0.42, respectively, which was statistically significant (P < 0.01).

The comparison between test and control groups from baseline to 3 months and 6 months has shown a higher gain in CAL. However, both test and control group showed a similar gain in CAL (P > 0.05). These findings, when correlated with the study done by Pourabbas et al.[12] was found to be consistent. CAL was significantly lower at the test site.

Aichelmann-Reidy et al.,[9] Wennström and Zucchelli[13] found improvement of CAL with no significant decrease in PD. Findings are in accordance with the results of this study. Cummings et al. demonstrated ADM adhesion to root surface by long junctional epithelium and connective tissue adhesion without sign of PDL entrance to root surface on histologic evaluation.[14]

The comparison between test and control groups from baseline to 3 and 6 months has shown a higher reduction in recession height. Both groups showed a similar reduction in recession height (P > 0.05).

Reduction in length of recession at both test and control group was due to coverage by ADM in the present study as it inhibits the apical migration of epithelium, repopulate the space by undifferentiated mesenchymal cells and promote regeneration resulting in a stable attachment of the flap to previously denuded root surface, preventing “subsidence of epithelium”[7] ADM facilitates better tissue maturation, resulting in long-term coverage of root.

On comparison between test and control groups from baseline to 3 and 6 months have shown a higher gain in WAG. But both test and control group showed a similar gain in WAG (P > 0.05).

A significant gain in WAG has been observed at both the test and control groups. Various biological determinants have been implicated in the alteration of gingival dimensions following perioplastic surgeries. Such determinants include; induced differentiation of gingival epithelium by morphogenetic stimuli from underlying connective tissue, intrinsic specialization resting within the basal cells of the epithelium and postsurgical reversal of the MGJ toward it genetically determined location.

The comparison between test and control groups from baseline to 3 and 6 months has shown that the ultrasonographic thickness of the gingiva was lower in the test group as compared to the control group, yet the difference between the two groups was statistically significant (P < 0.01).

The hypoechoic area on the ultrasonograph was increased at both control and test sites from baseline to 3 and 6 months. However, the hypoechoic area has shown lower in the test group as compared to the control group.

The gain in thickness might be due to the integration of the ADMA graft with the overlying flap. Although the control group had a significant gain in ultrasonographic thickness of the gingiva, this thickness can be attributed to the ongoing healing process. According to Burkhardt and Hürzeler,[4] microsurgical techniques using microsurgical instruments reduce the healing period and the resorption of the connective tissue grafts, therefore the time taken by microsurgically treated site shows the faster adaptation of graft as compared to control group.

The mean percentage root coverage for test and control groups at 3 months was 100 ± 0 and 91.67 ± 18, respectively, and at 6 months, the value for percentage root coverage for test and control group was 89.17 ± 18.4 and 81.67 ± 20, respectively, and was statistically not significant. More percentage of root coverage was obtained for test group.

The significant root coverage is associated with the Alloderm at both test (Microsurgery) and control (Macrosurgery) group patients might be due to the presence of collagen, that forms a major portion of the It also matrix. Collagen stimulates platelet attachment, enhances fibrin linkage, and is chemotactic for fibroblasts. ADM graft might act as a shock absorber, deflecting the undue forces. ADM graft facilitates better tissue maturation, resulting in root coverage for long time.[7] The degree of shrinkage is influenced by microsurgical procedures and finer instruments providing significantly improved outcomes than conventionally performed mucogingival surgery.[4]

The microsurgical technique showed a significant difference in ultrasonographic thickness of gingiva and the patient satisfaction score.

CONCLUSION

The present study demonstrated that the microsurgical approach for the management of GR was superior to the conventional one due to minimal tissue trauma with the use of fine instruments and the technique under magnification. Microsurgical sites healed faster with neovascularization, which was appreciated on ultrasonography, overall optimizing the results improving gingival thickness and patient satisfaction scores, making it a future legitimate method for evaluating perio-plastic aesthetic procedure.

Ultrasonographic measurement of gingival thickness yield promising results. Being atraumatic and nonionizing radiation, it offers new prospects for periodontal phenotyping, prevention, diagnosis, and therapeutic monitoring of periodontal disease.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Table 3

Group comparison of patient satisfaction on different parameters of assessment

Parameters	Control Group (n=10)		Test Group (n=10)		Significance of difference between two groups (Mann-Whitney U test)
	Mean	SD	Mean	SD	Z	P
Intraoperative	7.60	2.50	8.80	0.63	0.748	0.529
Postoperative	7.40	1.58	9.20	0.79	2.737	0.007
Hypersensitivity	8.40	1.17	9.40	0.52	2.256	0.043
Recession coverage	8.10	1.52	9.70	0.48	3.002	0.003
Appearance (color and form)	6.80	1.93	9.60	0.52	2.832	0.005