Conventional to minimally invasive root coverage procedures: Evidence-based literature review

Gunalan Kalaivani

doi:10.4103/mtsm.mtsm_13_21

REVIEW ARTICLE

Year : 2022 | Volume : 6 | Issue : 4 | Page : 89-100

Conventional to minimally invasive root coverage procedures: Evidence-based literature review

Gunalan Kalaivani
Periodontology and Implant Dentistry, Private Dental Practitioner and Consultant, Sivakasi, Tamil Nadu, India

Date of Submission	07-Aug-2021
Date of Decision	07-Oct-2021
Date of Acceptance	24-May-2022
Date of Web Publication	06-Oct-2022

Correspondence Address:
Dr. Gunalan Kalaivani
Department of Periodontology and Implant Dentistry, Private Dental Practioner and Consultant, 1/6/1129, Asari Colony, Satchiyapuram, Sivakasi (West) - 626 124, Tamil Nadu
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mtsm.mtsm_13_21

Abstract

In dentistry, various root coverage procedures (RCPs) are practising to treat gingival recession, still achieving complete root coverage (CRC) is more challenging. It even scales from conventional to advanced surgical RCP. The most important factor in achieving CRC is a proper presurgical evaluation by assessing the dimension of hard and soft tissues. Following the miller classification system, it helps to guide and predict successful RCP. Despite this, many dentists have struggled to implement RCP in their daily work. This article explains an evidence-based literature review to decide their actual outcomes, to address differing opinions and make informed choices before using various RCP. This will make a clinician choose the ideal RCP (either conventional or minimally invasive procedures) for the case at hand. To ensure that the expertise was accurate, an online search was conducted on the PubMed/Medline site. This included articles published between 2000 and 2019, all of which are related to positive results and the success rate of various RCP. A total of 796 articles of these were related to the RCP. The inclusion and exclusion criteria were used to select relevant papers. This review article aims to highlight the fact that RCP is believed to produce successful results. Advanced treatment mode of RCP aids in achieving a higher degree of performance than conventional RCP. For localized and generalized defects, subepithelial connective tissue graft, coronally advanced flap (CAF), and CAF + connective tissue graft are considered a more predictable option. However, there are several drawbacks to this RCP that must be found and addressed.

Keywords: Coronally advanced flap, free gingival graft, gingival recession, platelet-rich fibrin, root coverage procedures, root surface bio-modifier

How to cite this article:
Kalaivani G. Conventional to minimally invasive root coverage procedures: Evidence-based literature review. Matrix Sci Med 2022;6:89-100

How to cite this URL:
Kalaivani G. Conventional to minimally invasive root coverage procedures: Evidence-based literature review. Matrix Sci Med [serial online] 2022 [cited 2023 Mar 31];6:89-100. Available from: https://www.matrixscimed.org/text.asp?2022/6/4/89/358001

Introduction

Among various procedures in periodontal plastic surgery, root coverage procedures (RCPs) are considered to develop gradually. The reason impeding behind this is the lack of a logical answer for each question arising in the periodontium. By considering gingiva, think if it gets recedes whether it is possible to regain its original volume of tissue. Similarly, in the case of bone, periodontal ligament (PDL), and cementum loss; whether complete regrowth or regeneration is possible to achieve.

This lack of achievement might make us stepping backward. This is not a fault that lies in the researcher or clinician to achieve superior results. However, it is due to the unchangeable way of existing science and nature. Despite many studies, some problems need to be answered in RCP. It also hinders practising this RCP in the daily setup of clinical practices among dental practitioners. This is because of the failures encountered often.

Similarly, it can be reversed and can make RCP an enviable option among dental practitioners in the daily scenario. Interestingly, this can be achieved by the hands of a periodontist by focusing and eradicating the rudimentary problems encountered during these procedures. Still, many RCP is a great success from the past to the current scenario. It even scales from traditional to microsurgical procedures.

Here is the review to reflect and contemplate various RCP practising so far with their effective and default outcomes. Critical assessment is made by evaluating various clinical outcomes and failures encountered.^{[1],[2],[3],[4],[5],[6],[7],[8]} This gives us better knowledge and confidence to restore practices from conventional to minimally invasive techniques. Thus, the future practice can be enhanced simply and effectively by newer innovation techniques.

Methodology

A complete literature search was done on PubMed/Medline for articles available in the English language reviewing current RCP and recent advances using the terms “root coverage procedures with its success rate and failure.” The relevant papers were chosen according to the inclusion and exclusion criteria. A literature search revealed that most of the studies included were clinical studies, case series, and case reports of more than 6 months of follow-up; evidence-based reviews; systematic reviews and randomized controlled trial [Chart 1]. All publications focusing on case reports <6 months follow-up, animal study model, and other than RCP were excluded.

Currently Trained Pioneer Procedures

The surgical approaches are followed to augment, envelope, or preserve the root exposure area. Based on type, location, and the dimension of recession; the width of attached gingiva (WAG), vestibular depth, and interpapillary dimension determine the selection of suitable approaches for RCP. The following are the various RCP that are currently in use:

Flap technique

Grupe and Warren,^[9] introduced a technique called lateral sliding flap or rotational flap in 1956. It is considered as the first course of treatment option among various RCP. Later, modifications based on incision design, flap elevation, sutures, and graft placement have been described. It includes submarginal incision technique explained by Grupe et al. in 1966; partial-thickness pedicle flap technique described by Staffileno et al. in 1964; cut back incision technique proposed by Corn et al. in 1964; oblique rotated flap technique termed by Pennel et al. in 1965; double lateral repositioned flap technique given by Cohen et al. in 1968; periosteally stimulated flap technique coined by Goldman et al. in 1978; double lateral sliding flap technique given by Maragaff et al. in 1985 and transposition flap technique initiated by Bahat et al. in 1990.^[10]

Instead of sliding the flap laterally and facing its failure, then made the flap advancement coronally. It provides better clinical simplification and success in single and multiple teeth. In 1965, Harvey et al. applied this approach as a two-step procedure in combination with a free gingival graft (FGG). Later, many modifications based on incision and flap design have been tried by Allen and Miller in 1989, Wennstrom and Zuchelli in 1996, and De Sanctis and Zuchelli in 2007. Even, recession in single teeth has been practised with “semilunar coronally repositioned flap technique (SCPF)” as described by Tarnow et al. in 1986, whereas multiple teeth have been treated based on the “Zuchelli technique” initiated in 2000.^{[10],[11],[12],[13],[14],[15],[16],[17],[18],[19],[20]} The common practicing flap procedures for root coverage and its clinical success rate are enlisted in [Figure 1] and [Table 1].

Figure 1: Current practicing flap techniques and procedures.^[10],[11] GR: Gingival recession

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Table 1: Currently practicing root coverage procedures with their clinical success rates

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Autograft technique

This approach is planned when donor tissue adjacent to recession is deficient. The various donor sites for soft tissue grafting:

Palate (Most RCP harvest graft from palate and yield predictable outcomes)
Maxillary tuberosity
Edentulous area
Buccal pad of fat.

In 1963, Bjorn et al. introduced the classic technique by using FGG. Later, this technique is modified that includes the Miller modification technique explained in 1982, the accordion technique given by Ratischek et al. in 1985, the strip technique initiated by Han et al. in 1993, and the combination technique.^[10] In 2007, Allen^[21] modified this FGG as a gingival unit graft. It comprises marginal gingiva and papilla along with conventional FGG.

Connective tissue graft (CTG) was introduced by Edel et al. in 1974, but the procedure has failed initially. Unlike conventional FGG, CTG has used as a submerged graft. Later, the CTG technique has been revised by Langer and Langer in the year 1985 and termed subepithelial connective tissue graft (SECT). Furthermore, Raetze et al. described the envelope flap technique in 1985, Nelson et al. described the Bilaminar approach in 1987, and Bruno et al. suggested the modified Langer and Langer flap technique in 1994.^{[10],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31]} The common practicing autograft procedures for root coverage are illustrated in [Figure 2] and [Table 1].

Figure 2: Commonly using soft tissue grafting procedures.^[11] CEJ: Cementoenamel junction, CTG: Connective tissue graft, 1-primary, 2-secondary incision

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The various incision designs have been described to obtain CTG. Initially, the trap door technique has been followed by Edel et al. in 1974. Then, Raetze et al. in 1985 described the technique called semilunar incision, Harris et al. in 1992 designed parallel incision technique, and Bruno et al. in 1994 used a modified wedge technique.^[10] Lately, Liu and Weisgold^[32] in 2002 designed a classification system for CTG incision. Thus, a simple incision for SECT is more preferable to the trap door technique.

Guided tissue regeneration

Biological substitutes like a nonbioresorbable membrane (titanium mesh) and bioresorbable membrane (collagen) can be used to replace autograft. Pini Prato et al. in 1995 used a resorbable membrane for achieving success in RCP. Later, many studies have been shown successful outcomes by using GTR [Table 1]. This helps to achieve both soft tissue and hard tissue gain. Currently, GTR has been used as a successful RCP that counteract extra-needed surgery for graft harvesting.^{[33],[34],[35],[36]}

Tunneling approach

Allen et al. 1994 modified the envelope technique by giving intrasulcular incision followed by tunneling or supraperiosteal preparation to manage multiple teeth recession [Figure 3]. Later, Azzi and Etienne in 1998 had explained the pouch and tunnel technique.^[10] Various modifications have been proposed based on the incision design, graft material, and flap design.^{[37],[38],[39]} A single vertical incision is one such modification technique used by Zabalegui et al.^[37] in 1999, and Santarelli et al.^[38] in 2001. The current success rate using this procedure is explained in [Table 1].

Figure 3: Minimally Invasive Surgical Technique.^{[60],[61],[62],[63],[64]} VISTA: Vestibular incision subperiosteal tunnel access, PST: Pinhole surgical techniques, GDT: Gum drop technique, MCAT: Modified coronally advanced tunnel technique

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Combination approaches

The combination of CTG and pedicle flap is to enhance vascularity and increasing WAG by an approach called sub-pedicle CTG. It includes either a full-thickness flap explained by Nelson^[43] in 1987 or a partial-thickness flap described by Harris^[44] in 1992. Epithelial embossed CTG, another type of combination approach described by Sterrett^[45] in 2008 comprises overcoating CTG with embossed epithelium in the center resembling a single unit graft. Practically, both approaches are technically challenging.

At present, coronally advanced flap (CAF) is the most commonly used procedure in multiple teeth recession management. It is found to be a standard treatment protocol when combined with CTG yielding high success rates. Despite the CTG harvesting technique and insufficient volume of the graft, many substitutes arouse to replace CTG.^[4] The various combination approaches commonly practising with CAF are explained in [Figure 4].

Figure 4: Combination of coronally advanced flap procedures. CAF: Coronally advanced flap, ADMG: Acellular dermal matrix graft, CTG: Connective tissue graft, GTR: Guided tissue regeneration, PRF: Platelet rich fibrin, XCM: Xenogeneic collagen matrix, SCPF: Semilunar coronal positioned flap, EMD: Enamel matrix derivative

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Silverstein and Callan.^[24] used acellular dermal matrix graft (ADMG) named alloderm, a cadaveric human dermal tissue enriched with collagen matrix for increasing width of keratinized tissue (KT) around teeth and implants. Harris^[46],[47] observed adequate achievement in RCP using ADMG compared to CTG in their clinical studies.

Enamel matrix derivative (EMD) is combined with various RCP. Emdogain is an FDA-approved derivative protein contain amelogenin with variable molecular weight. It induces acellular cementum formation with newly formed bone and organized PDL. A study was done by Carnio et al.^[48] revealed a combination of SECT with EMD shows better healing without the formation of long junctional epithelium and evidence of regeneration in a certain area. Concurrently, McGuire and Nunn^[49] suggested a better outcome when used in conjunction with a CAF compared to SECT. Histologically, EMD shows regeneration mimicking tooth development as a natural process.

Platelet-rich fibrin (PRF) is enriched and concentrated growth factors obtained by centrifugation (2700 rpm for 12 min) from platelets. It is used as a graft substitute or carrier and applied in various RCP. It stimulates angiogenesis and improves collagen synthesis. It decreases healing time and creates tissue maturation within 4 weeks, and also increases tissue thickness. The superior results of PRF have been shown by Cheung and Griffin^[50] achieving 80% root coverage in Miller class I and II, Yen et al.^[51] reported accelerated wound healing and type I collagen formation under histological view, and Griffin and Cheung^[52] suggested it as a graft substitute carried by collagen sponge.

Microsurgical-assisted procedures

Microsurgical-assisted procedures called minimally invasive surgical technique (MIST) described by Cortellini and Tonetti^[53] paves a lesser traumatic approach and better clinical results when compared to other RCP [Table 1]. The use of microsurgical instruments has improved wound healing, esthetic outcomes, the adequate blood supply to the SECT and even simplify the technique-sensitive tunneling approach.^{[40],[41],[42]}

Current Biological Principles of Root Coverage Procedures

The healing phases of a soft-tissue graft or flap are an important measure to consider for a successful procedure [Chart 2]. The biological linkage is the basic principle needed to bridge the soft tissues and denuded root surface [Chart 3].

Additive treatment is used with chemical and biological agents to achieve histocompatibility. The main principle is decontamination by removing toxic substances from the root surfaces. Earlier, chemical root surface bio-modifier is used by applying tetracycline hydrochloride (50–125 mg/ml for 3–5 min) and citric acid for 3 min with pH 1 and ethylenediaminetetraacetic acid (24% gel with pH 8.5 for 2 min). Despite inferior results attained over chemical agents, the biological agent includes platelet-rich plasma, PRF, EMD, growth factors have been applied.^{[54],[55],[56], [57,[58]}

Adequate vascularity promotes better healing properties. The FGG has a distinct blood supply from the periosteum and PDL. Whereas CTG and lateral pedicle flap survive from the dual blood supply from periosteal connective tissue bed and overlying flap. The flap thickness (>0.8 mm) is necessary for complete root coverage (CRC). It is more evident in CAF as described by Baldi et al.^[59] for achieving CRC. Excess flap tension and flap retraction have deleterious effects on successful procedures. Initial thin clot formation makes the healing tissue reach a stable and successful bond without failure by graft rejection. Another biological event that has encountered is wound contraction; creating a detrimental recession in the postoperative scenario. Suturing the flap coronal to the cementoenamel junction (CEJ) by 1–2 mm will overcome the shrinkage. Thus, adhering to biological principles will cover the root surface to a greater adhesion with soft tissue graft/flap.^[11]

Multifactor Analysis for Successful Root Coverage Procedures

Many factors are present in predicting the success of RCP.^{[1],[2],[3],[4],[5],[6],[7],[8],[11]} Still, a debate is argued over the years about RCP and its success rate. The multifactor analysis is described in [Figure 5].

Figure 5: Multifactor analysis for successful root coverage procedures

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Advancement in Root Coverage Procedures

For achieving complete and successful root coverage, many MIST and biological agents are advanced. The various modalities in this field are explained as:

Minimally invasive surgical procedures

Vestibular incision subperiosteal tunnel access (VISTA)
Pinhole surgical techniques (PSTs)
Gum drop technique (GDT)
Modified coronally advanced tunnel technique (MCAT).

Advanced graft materials

Partly epithelized FGG (PE-FGG)
Biological substitutes.

Placental allograft
Decellularized human dermis
Xenogeneic collagen matrix (XCM).

Healing boosted approaches

Advanced PRF (A-PRF)
Injectable PRF (i-PRF)
Gingival fibroblast
Laser-assisted procedures.

Minimally Invasive Surgical Procedures

The novel approaches such as VISTA and PST are described by Zadeh^[60] and Chao.^[61] They are designed by a special instrument with a single-incision technique for covering multiple recessions and utilizing biological substitutes as an adjunct. Recent studies proved VISTA and PST exhibit a higher level of success by showing effective and profitable outcomes [Figure 3]. It overcomes releasing incisions and various sutures. Still, many clinical trials are ongoing to spectacle its promising outcomes.

GDT is a novel procedure described by Tuttle et al.^[62] Four holes (laparoscopic size) are prepared by a small piercing instrument apical to the mucogingival junction (MGJ). Using the appropriate elevator, the tunnel is created using the full-thickness flap and the papilla is spared. Irrigation with plasma exudate is done. Then, A-PRF (1300 rpm/8 min) is placed into the hole to obtain sufficient thickness. Then, the tension-free flap is pulled coronally and sutured. Later, i-PRF is injected at the PDL space to enhance healing [Figure 3].

The MCAT is one of the recent treatments for multiple recession teeth. It has many advantages by avoiding papillary involvement and releasing vertical incisions to improve adequate vascularity. The combination with coronal advancement makes soft tissue or substitution graft cover complete recession area and it improves the survival rate of the graft. Studies were done by Aroca et al.^[63] and Hofmänner et al.^[64] indicated that MCAT with CTG is a more predictable technique for treating Miller Class III recession [Figure 3].

Advanced Graft Materials

Autograft

Cortellini et al.^[65] have modified the conventional FGG approach as PE-FGG. In this approach, the coronal portion of the graft is placed between the level of MGJ and CEJ with its apical portion is deepithelized to match with the recipient site for providing better esthetics. In a study done by Mahajan^[66] using a periosteal pedicle graft reported satisfactory root coverage and accurate color match.

Allograft

Many biological substitutes are approaching to compensate patient hesitancy for the extra surgical site needed for graft harvesting. The advanced allograft materials are enlisted:

Placental allografts

The application of placental allografts such as amniotic membrane (AM) and chorion membrane (CM) have been a greater initiation for successful outcomes in RCP. Evidence has shown by Gurinsky^[67] using AM attained adequate graft coverage, improved healing, and better handling properties for managing multiple teeth recession. Esteves et al.^[68] using CM achieved favorable results in RCP when used with the modified CAF technique. Moreover, it shows improvement in the gingival biotype and width of KT. Recently, Pundir et al.^[69] pointed both AM and CM yield better outcomes in RCP. Histologically, the placental membrane was found to mimic the extracellular matrix structure by providing successful regeneration in RCP.

Decellularized human dermis (OrACELL™)

A novel allograft material called decellularized human dermis (OrACELL™) has used by Vreeburg et al.^[70] providing the best alternative to CTG for class III recession. Still, many sorts of research are forthcoming using this material to provide promising results in the future.

Xenograft

XCM is commercially obtained from porcine, bovine, and equine. They are bilayer biological substitutes having better handling properties and enhance cellular recruitment and vascularization. Studies by McGuire and Scheyer^[71] and Cardaropoli et al.^[72] showed that XCM has efficient and expectable results with an increased width of KT and a lesser morbidity rate when compared to CTG. In contrast, Jepsen et al.^[73] found combination of XCM + CAF is not superior to other RCP. However, Stefanini et al.^[74] in their multicenter clinical trial found that XCM + CAF has superior results.

Healing Boosted Approaches

The new blood-derived biologics named A-PRF and i-PRF are combined with various RCP to yield faster healing and tissue volume gain. These derivatives are used in the GDT procedure to improve healing, tissue phenotype, and biocompatibility.^[62] Currently, many works of literature that support the application of emdogain are shown to advance tissue reattachment and healing.^{[42],[48],[49],[58]} In fact, the majority of the clinical and evidence-based scientific reports has proven to show that PRF has more beneficial efforts by retaining its “tissue-glue” like properties at hard- and soft-tissue levels. In addition, inexpensive costs make it more affordable. Further studies are needed to prove the healing effort of biological derivatives.

Gingival fibroblast

Biodegradable scaffold with suspended cells of gingival fibroblast has helped to achieve better outcomes after the surgery demonstrated by Murata et al.^[75] Still, these procedures are technique sensitive and under research process.

Laser-assisted procedures

In RCP, Ozcelik et al.^[76] used a diode laser to harvest the graft from the palate region, then applied as a biological bandage on the donor site [Figure 3]. LAP also helps in conditioning the denuded root surface. Lasers like neodymium-doped yttrium aluminium garnet (Nd:YAG) used by Dilsiz et al.^[77] erbium, chromium: Yttrium scandium gallium (Er, Cr: YSGG) used by Poormoradi et al.^[78] and erbium-doped yttrium aluminium garnet (Er-YAG) used by Kina et al.^[79] found to show better improvement in SECT procedures. Even, LAP has helped the flap to position laterally in a precise manner as demonstrated by Yilmaz et al.^[80] in their clinical trial. Hence, minimal flap mobilization for better wound stability and healing has been achieved using LAP.

Decision Tree for Choosing Root Coverage Procedures

Until date, a large number of successful RCPs are in use daily. However, the decision-making for choosing precise and needful RCP is described in [Figure 6].

Figure 6: Decision tree for choosing appropriate root coverage procedures.^[1] SECT: Subepithelial connective tissue graft, FGG: Free gingival graft, LPF: Lateral pedicle flap, CAF: Coronally advanced flap, ADMG: Acellular dermal matrix graft, GTR: Guided tissue regeneration, XCM: Xenogeneic collagen matrix, EMD: Enamel matrix derivative, CRC: Complete root coverage

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Future Outlooks with Newer Innovation

The future techniques looking for success in the RCP will be:

Recombinant growth factor
Tissue engineering in soft-tissue achievement
Rapid prototype technique for soft- and hard-tissue printing.

Limitation

This review explains the various RCP followed currently with their expected success rate and the problem encountered in reality. The problem-based solution to each procedure is failing to explain in a detailed manner. Only Miller classification is considered for deciding the various treatment choices and analyzing their prognosis. Recently, many classification systems for gingival recessions and their prognosis assessment are developed.^[81]

Conclusion

Currently, SECT, CAF, and CAF + CTG consider as a more predictable options for localized and generalized RCP. Spotting a recent advancement, a minimally invasive surgical RCP with the use of biological agents may have a more conservative and successful approach. Based on patient-related factors and clinician knowledge, better choice of treatment and surgical skills helps to yield CRC with an excellent prognostic outcome. Even, future innovation will be a card for the massive success in RCP.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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