1. INTRODUCTION
Most patients now require dental changes that are not carious due to the general information available about oral health and how they should clean their teeth. An increase in the prevalence of gingival recession (GR) in adults and young peoplehas been observed. This may be due to inadequate brushing associated with factors that predispose or trigger the occurrence of GR.
Teeth with long clinical crowns impair the look of the smile. The height/width ratio is unsatisfactory due to a change that occurred at the cervical level. In addition to esthetic issues, the patient may present1 carious or non-carious cervical lesions, cervical dentin hypersensitivity, difficulty in cleaning, and progressive loss of periodontal attachment (Figs 01A–I).
01. A–I Patient presenting with a complaint about GR. The treatment previously proposed in his home country was extraction to eliminate cervical dentin hypersensitivity. To resolve his clinical situation, surgery was proposed to cover the root surfaces.
Due to injuries to the periodontal tissue, the level of the gingival margin migrates apically, exposes the cementoenamel junction (CEJ), and characterizes the occurrence of GR2. Depending on the type of recession, it is possible to perform surgical procedures to manipulate the gingival margin coronally and obtain a better positioning of the gingival zenith.
Correct diagnosis, careful planning, and careful manipulation of soft tissues around the GR are crucial for a favorable and predictable prognosis of root coverage. Thus, some factors must be analyzed before the surgical procedure to determine the best procedure to be adopted.
OBJECTIVES
At the end of the chapter the reader should be able to:
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Identify the types of GR.
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Establish the predictability of root coverage surgery.
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Choose the most suitable technique for the treatment of GR.
2. SCIENTIFIC BACKGROUND
2.1. ETIOLOGY AND CLASSIFICATION OF GINGIVAL RECESSION TYPES
The first step for correcting GR and preventing future relapse is to determine its etiology. Most of the adult population has at least one site with GR3 and its cause is multifactorial. The factors that cause recession can be divided into predisposing and triggering factors (Table 01 and Figs 02A–G). Three factors are strongly associated and deemed crucial for the occurrence of GR:
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Bone dehiscence.
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Thin gingival biotype.
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Inflammatory process caused by periodontal infection or mechanical trauma.
|
PREDISPOSING FACTORS |
TRIGGERING FACTORS |
|---|---|
|
Bone dehiscence or fenestration |
Traumatic brushing |
|
Reduced bone and gingiva in the free and proximal surfaces |
Dental movement outside the bone socket |
|
Lack of attached gingiva |
Plaque-induced inflammation |
|
Inappropriate teeth positioning |
Violation of the biologic width |
|
Abnormal insertion of the frenulum and vestibule |
Trauma to the soft tissues due to removable partial denture , piercing, or habits |
Table 01. Predisposing and triggering factors for gingival recession
02. A–G Patient with a thin biotype diagnosed due to gingival color change with insertion of a probe into the sulcus (A–C). Inflammation in the periodontium generates the release of collagenases, which degrade gingival connective tissue; epithelial ridges migrate to the resorbed space until the ridges of the oral epithelium merge with those of the sulcular epithelium (D–E). Consequently, the periodontal tissue no longer receives nutrition (F) from the connective tissue; the cells initially enter a hypoxic condition, which is followed by anoxia and, consequently, programmed cell death. Apoptosis of these cells leads to desquamation of the most coronal portion of the periodontium, resulting in GR in areas of thin biotype (G). D–G images have been adapted from Novaes and Novaes1.
GR may occur in any periodontal site. Usually, patients with periodontitis and inadequate control of dental biofilm have recessions on all faces4. Patients with a low plaque index can also present GR but GR is usually found on the free surfaces and is associated with mechanical brushing or flossing trauma5. Both periodontal disease and mechanical trauma have the potential to cause periodontal damage (Figs 03A, B to 05A–C). It is essential to eliminate this aggressive process before performing a surgical procedure.
03. A, B Mechanical trauma due to flossing.
04. A–C Patient with a history of periodontal disease with generalized attachment loss associated with loss of papillae and gingival recessions.
05. A–C Patient with early gingival recessions due to brushing, and buccal and lingual trauma.
Miller6 proposed a classification for GR where, besides defining the design of the defect, it offers a prognosis of root coverage procedures based on the presence or absence of intact interproximal periodontal tissues. The classification states that in class I and II GR, 100% of coverage can be achieved. This is because of the presence of intact interproximal periodontal support and consequent blood and structural supply to the flap. In class III and IV GR, where interproximal tissues are partially or entirely lost, compromising the tissue support positioned over the GR, the same results cannot be expected (Table 02 and Figs 06A–D).
|
CLASS I |
Gingival recession that does not extend beyond the mucogingival line and shows no loss of interproximal support tissues: full coverage is predictable. |
|
CLASS II |
Gingival recession that reaches or exceeds the mucogingival line and shows no loss of interproximal support tissues: full coverage is predictable. |
|
CLASS III |
There is loss of interproximal support coronal to the extension of the buccolingual recession: predictability of partial coverage. |
|
CLASS IV |
There is loss of interproximal support at the same level or apical as the extent of the buccolingual recession: no cover predictability. |
Table 02. GR types according to Miller6
06. A–D GR types according to Miller6.
The presence of interproximal bone is not the only factor that should be considered to obtain favorable results7. Several systemic, environmental, and local aspects, as well as the choice of different coverage techniques, may influence the outcome (Figs 07A–D).
07. A–D Treatment of periodontal disease is not currently limited to achieving periodontal health only. Corrective surgical procedures may be necessary to reconstruct part of the lost tissue.
Traumatic brushing is one of the leading causes of GR and may occur due to excessive force, frequency, and time of brushing, type of bristles, and toothpaste8. Oral hygiene techniques should be reviewed to prevent GR relapse (Figs 08A–C). An alternative to control the pressure is to instruct the patient to start brushing the lingual surfaces, finishing brushing in regions with more severe GR. Electric toothbrushes may also be indicated to prevent excessive trauma to the periodontal tissue. A randomized clinical trial demonstrated that the use of these toothbrushes showed better stability of the gingival margin after root coverage9.
08. A–C Patient with short and long clinical crowns who presented with mechanical trauma on the left side. In tooth 22 the trauma was caused by both brushing and flossing. The patient was properly oriented before periodontal plastic surgery to correct the present changes.
The periodontal biotype should be taken into consideration in surgical planning to correct GR. Baldi et al10 assessed the thickness of the flaps (Figs 09A, B) for root coverage. The results showed that when the flap was thicker than 0.8 mm, a prognosis of total coverage was higher than when the tissue was thinner. Other clinical studies corroborate with these results but emphasized the difficulty in measuring the thickness of the flap during the surgery11,12.
09. A, B Successful treatment of GR depends on the thickness of the flap, which may be thin (A) or thick (B).
The dimensions of the papillae adjacent to the defect are crucial since they are responsible for stabilization and nutrition of the flap. Long papillae favor the stabilization and nutrition of the flap, favoring the outcome13. Methods to predict the amount of root coverage, taking into consideration the architectureof the papillae and its relationship to the CEJ, were proposed by Zucchelli14 (Figs 10A–I). Poorly positioned teeth, reduced papilla height and volume, prominent roots, and cervical lesions can make it challenging to cover the root surface entirely, choose the appropriate surgical procedure, and combine it with restorative or orthodontic procedures.
10. A–I The height of the papillae and its relationship to the CEJ (x) can be used to predict the amount of root coverage. When the papillae are intact, it is possible to obtain complete coverage (A–C). If one of the papillae is partially lost, partial coverage can be achieved and the zenith will usually be directed to the compromised papilla (D–F). Partial loss of the two papillae will limit the treatment of gingival recession; root coverage is expected to be approximately 70% (G–I).
2.2. TECHNIQUE SELECTION
The technique for treating GR is sensitive to the operator and the surgical procedures adopted. Different types of root coverage surgery have been described in the literature15,16. However, despite some technical differences, several universal principles help define a better prognosis and determine which technique should be employed according to the characteristics of GR.
2.2.1. ROOT SURFACE TREATMENT
After case selection and planning, the first question that emerges is how to treat the root surface exposed to bacteria, acids, and different substances. The exposed root surface should be decontaminated before positioning the flap that will correct the GR. This decontamination can be done by prophylaxis, manual scaling with periodontal curettes, or ultrasonic decontamination; however, there is no clinically significant difference between these techniques17,18. We prefer the use of curettes or ultrasonic instruments because they are less aggressive to the gingival margin. Surface biomodification can be done with 24% ethylenediaminetetraacetic acid, citric acid, or tetracycline. There is no proven clinical advantage and its use is not necessary19,20.
The association of root coverage techniques to enamel matrix-derived proteins—enamel matrix derivative (EMD) has shown promising results (Figs 11A–C). Spahr et al21, in a clinical study with a 2-year follow-up, concluded that both treatment modalities presented satisfactory results, with better results when the technique was associated with EMD. Complete GR correction showed more stable results in cases treated with EMD, whereas recurrence of GR was more frequent in cases treated with surgery alone. In theory, the use of EMDs may allow the formation of not only the long junctional epithelium in the covered defect but also partial regeneration of support tissues at the base of the defect. This hypothesis would justify greater predictability and stability for the treatment of long-term GR but needs to be scientifically proven22,23. Another advantage found in the association of EMD with surgery is the anti-inflammatory potential of this biomaterial, where earlier healing can be found.
11. A–C Use of EMD-derived proteins on the root and flap surface. Surgical procedure: Dr Cristiano Pascoal.
2.2.2. SURGICAL TECHNIQUES
Regardless of the technique chosen for root coverage, the flap should always be positioned over the gingival defect and kept completely free of tension. Pini-Prato et al24, in a clinical study, stated that the tension-free flap contributes to a higher percentage of root coverage. This elimination of tension is achieved by releasing the flap in the alveolar mucosa region. The techniques initially described suggest a partial-thickness flap from the gingival margin; however, it is recommended to keep a full-thickness flap in the gingival margin to maintain tissue volume. The flap should be divided only from the mucogingival junction, with scalpel blades or dissectors, where the alveolar mucosa allows the elimination of tension promoted by its collagen fibers (Figs 12A–C). It is possible to see absence of tension when the manipulation of the lip does not cause the flap to move when the flap is covering the root surface.
12. A–C Flap release at the mucogingival junction. An incision is made at the base of the periosteum inserted into the bone tissue and then the flap is carefully divided to avoid lacerations.
Another maneuver that seeks to eliminate tension is the making of divergent relaxing incisions. The flap can be made into a trapezoidal or triangular shape (Figs 13A, B). Zucchelli et al25 demonstrated a higher incidence of scars when performing trapezoidal flaps. A triangular shape is recommended in areas or for patients with higher esthetic demand. Although allowing a full-thickness flap release, this maneuver can compromise the blood supply of the flap and impair healing. Thus, the need to include releasing incisions will depend on the amount and extent of GR18,26.
13. A, B Triangular (A) or trapezoidal (B) vertical incisions may be made for coronal flap repositioning.
Elimination of flap tension is a critical factor in achieving another essential variable for root coverage prognosis: the final position of the flap. Pini-Prato et al27 evaluated the influence of the final location of the gingival margin after surgery. They concluded that a 2-mm coronal positioning of the flap in relation to the CEJ considerably increases the prognosis of full coverage of the GR (Figs 14A–C and 15A–D). Another factor to be considered is the position of the connective tissue graft in relation to the CEJ. In general, the graft should be stabilized at the level or up to 1 mm apical to the CEJ. If it is necessary to increase the amount of keratinized tissue, in addition to root coverage, approximately 20% of the graft can be left exposed since there will be nutritional support for the remnantof the graft under the flap28.
14. A–C Flap sutured apically (A), at the level (B), and coronal to the CEJ (C). The flap should not be sutured beyond the CEJ if there is interproximal bone loss or a restorative treatment plan to be followed, where coverage beyond the established level will cause an esthetic change.
15. A–D A different result is expected in relation to root coverage when repositioning the flap at the level (A, B) or beyond the CEJ (C, D). If full coverage is desired, it is important to reposition the flap 1–2 mm coronal to the CEJ.
The main histological difference between a thin and a thick gingival biotype is the volume of connective tissue. Thus, the association of the subepithelial connective tissue graft (SCTG) with techniques for root coverage aims to increase gingival thickness and obtain a biotype to prevent GR relapse10. The SCTG is adapted between the surgical bed and the flap and can be stabilized separately with bioabsorbable sutures or in adjacent areas or in the flap/adjacent tissue with conventional sutures (Figs 16A–C).
16. A–C The graft can be sutured to the flap (A), recipient area (B), or adjacent areas (C). Only in situations where the sutures will be inside the tissue, there is a real need to use bioabsorbable sutures.
Research showed similar results between the two techniques (isolated flap vs flap associated with SCTG). Short-term follow-up showed that the correct flap manipulation determines root coverage16. However, due to modification in tissue biotype, the region that received the tissue graft is more resistant to trauma and injuries, reducing the risk of relapse in the medium or long term. Thus, it is suggested that GR with a gingival margin thickness of less than 1 mm should be treated with the associated technique29–31.
The treatment of GR still represents a challenge to the clinician due to the extension of the surgical field, severity of the lesion (Table 03), and limited amount of connective tissue at the donor site32.
|
EXTENSION |
SEVERITY |
|---|---|
|
Isolated |
Shallow (height < 4 mm) |
|
Multiple |
Deep (height ≥ 4 mm) |
Table 03. Types of recession according to extension and severity
Another important factor is compromised vascularization in the grafted area due to the height and width of exposed root surfaces in cases of multiple recessions33.
Some systematic reviews concluded that SCTG demonstrated greater predictability for complete root coverage and increased thickness and width of keratinized tissue after treatment of multiple Miller class I and II recessions32,33. This surgical technique can be considered a “gold standard” (Figs 17A–H) for the treatment of localized Miller class I and II GR31.
17. A–H Types of GR according to its extent and severity. Shallow and isolated (A), shallow and multiple (B), outcomes (C, D); deep and isolated (E), deep and multiple (F), outcomes (G, H) after surgical treatment through coronally positioned flap associated with connective tissue graft. Cases partially published by Ottoni et al15 and Frizzera et al64,67. Surgical procedures: Dr Fausto Frizzera.
Even with the benefits described in the literature, SCTG is often associated with patient morbidity due to postoperative complications related to the donor area, usually the hard palate34,35. Additionally longer surgical time, pain, and discomfort are associated with this technique36,37. These factors are aggravated in cases of treatment of multiple adjacent recessions, where more graft tissue is required. Some alternative surgical techniques are being compared to SCTG for the treatment of GR.
Collagen matrix from pigs—Mucograft (MC)—has been marketed as a possible alternative to soft tissue grafts in increasing the range of keratinized tissue around teeth and implants36. Some studies have also used MC in the treatment of localized38,39 or multiple40 Miller class I and II GR. The benefits described are often related to the patient’s lower morbidity because graft removal is not necessary39,41. When used for the treatment of localized GR, the percentage of root coverage was 75.29% (6 months), 88.5% (12 months), and 77.6% (5 years)37–39. In the treatment of multiple GR, the percentage of root coverage was 93.25% at 12 months40; however, clinical studies on the performance of this type of treatment in both intact and severely damaged root surfaces are still limited.
Non-carious cervical lesions are common findings in regions of GR because the exposed root surface is less resistant to abrasion. Thus, simple brushing leads to wear of the exposed root cement and even on dentin. In most of these cases, in an attempt to eliminate hypersensitivity, lesions are restored. Scientific studies support the positioning of the flap over restorations, whether in glass ionomer cement or composite resin42,43. If optimal polishing and a well-matched tooth restoration margin cannot be achieved, replacement of the restoration is recommended. The cervical lesion should be treated using an SCTG.
2.2.3. SURGICAL TECHNIQUES TO TREAT GR
To correct GR, several techniques of periodontal plastic surgery have been described and analyzed in the literature. The choice of surgical procedure will depend on the extent and severity of the GR. Several procedures have a good prognosis of coverage but their success depends on the correct selection and indication of the technique44.
Periodontal plastic surgery for root coverage can be classified into45:
I. Free grafts
II. Surgical techniques with pediculated flaps:
a. Rotated flaps;
b. Coronally positioned flap.
FREE GRAFTS
An incision is made on the recipient area by the mucogingival junction and the buccal flap is divided. The epithelium on the coronal portion of the recipient area is removed. The gingival graft from the palatal masticatory mucosa is then sutured (Figs 18A–F). The graft can have epithelial and connective tissues or just connective tissue (SCTG); a collagen (CM) matrix can also be used in specific clinical cases. This technique can be performed directly, with a single procedure, where the graft covering the GR is stabilized. It can also be used primarily to increase the height and thickness of the gingival tissues apical to the GR. As a second step, a coronally positioned flap can be performed46,47.
18. A–F Increased amount of attached gingiva through deepening of the vestibule and a free gingival graft by conventional technique. Two years after surgery, color and texture changes were observed, which were exacerbated by the presence of melanin pigments. Surgical procedure: Dr Fausto Frizzera.
Free gingival graft is a technique widely studied in the literature. Despite presenting long-term stable results48, it is associated with limited outcomes regarding root coverage. It depends directly on graft nutrition by the recipient area and graft thickness, ideally 2 mm thick.
On average, root coverage ranges from 39% to 100% and is the most predictable technique for shallow defects. However, esthetic results are not satisfactory due to the discrepancy of shape and color between the grafted tissue and the tissues of adjacent areas (Figs 19A–I and 20A–H). While most patients expect esthetic excellence, this technique has been recommended for cases of GR in regions with low esthetic demands, with no attached gingiva, and shallow vestibule depth49.
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