Overview of Periodontal Surgical Procedures

Anatomy and Physiology

Bone Defect Morphology

Periodontal bone lesions are the result of the apical spread of periodontal disease. Understanding the morphology of bone defects is crucial for planning periodontal surgery. Bone loss is primarily described as horizontal or vertical, according to the pattern of tissue destruction. Bone defects are also described as having shallow or deep defects and up to 3 wall defects, depending on the number of remaining walls. The number of walls indicates the potential for periodontal regeneration, while the depth of the defect influences the choice between resective, regenerative, or tooth extraction treatment strategies. Whether horizontal or vertical, the pattern of bone loss determines if surgical treatment includes treating the alveolar bone.

Horizontal bone defects refer to a generalized apical shift of the alveolar bone crest. When seen on x-rays, a distance greater than 1.9 mm from the cementoenamel junction (CEJ) indicates a high likelihood of bone and attachment loss.[10] Vertical defects typically appear as localized fading of the normally well-defined crestal bone, wedge-shaped areas of radiolucency adjacent to root surfaces, or multiple bone levels. Vertical defects are also known as intrabony defects. Tipping of teeth may cause wedge-shaped dips in the crestal bone as part of normal bone remodeling. But, unlike periodontal bone defects, the crestal bone will follow a line connecting the interproximal CEJ of adjacent teeth in such cases.

Shallow vertical bone defects range from uneven crestal bone to defects of approximately 3 mm deep, easily recognized on radiographs.[11] A defect is considered deep if it is greater than 3 mm. Three-wall defects are typically found in posterior areas with wide interproximal bone consisting of a buccal, lingual, and interproximal wall. Three-wall defects may also be found at buccal or lingual furcations facing a bone shelf or exostosis. As the mesiodistal volume of the interproximal bone decreases, 3-wall defects may merge and form 2-wall defects called interproximal craters, where only the buccal and lingual walls remain. A 2-wall defect with a buccal and interproximal wall may develop adjacent to the entrance of the interproximal furcation of maxillary molars.

One-wall defects are typically found in areas with narrow interproximal bone, such as closely spaced maxillary molars with furcation involvement or anterior teeth like mandibular incisors. In some cases, localized periodontal bone loss may obliterate the interproximal bone, especially in cases of root proximity, resulting in a localized bone defect with no walls.

Relationship of Bone Defects to Periodontal Pockets

A pseudopocket is a periodontal pocket with a base coronal to the underlying crestal bone and terminating at or coronal to the CEJ. Pseudopockets are typically associated with thick fibrous gingiva or altered passive tooth eruption. A periodontal pocket with a base coronal to the underlying crestal bone but exhibiting attachment loss is referred to as a suprabony pocket. If a periodontal pocket has a base extending deeper than the most coronal aspect of the adjacent crestal bone, it is called an infrabony pocket. Infrabony pockets are typically associated with deep probing depths and vertical bone defects. Suprabony pockets are typically associated with horizontal bone loss and shallow probing depths.

Microvascular Considerations for Periodontal Surgery Flap Design

Periodontal tissues receive microvascular blood supply from different directions. Arterial blood flow is from distal to mesial, from apical to coronal, and from both lingual and facial directions toward the center of the interdental papilla. Interproximal tissue is supplied by blood vessels emerging from the alveolar crest, blood vessels from the periosteum covering the buccal and lingual alveolar cortex, and capillaries from the periodontal ligament. Buccal and lingual tissues are supplied by blood vessels traveling coronally on the soft tissue side of the alveolar periosteum, along with additional superficial blood vessels underlying the mucosa.[12][13] Typically, larger superficial blood vessels are found in the canine-premolar region. Areas of thin buccal tissue may have limited blood supply.

Interproximal tissue is at the end of the blood supply. Envelope incisions result in limited capillary bleeding and are preferred for simple periodontal pocket reduction. Vertical-releasing incisions tend to cut superficial mucosal vessels, increasing intraoperative bleeding. By identifying superficial blood vessels and using curved vertical releases parallel to mucosal blood vessels, bleeding from the releasing incision and scarring can be reduced. As facial tissue is the thinnest and has the least blood supply, vertical releases should not be placed over facial mucosa. If surgical access requires a rectangular flap with 2 vertical incisions, the releases should be parallel to the mucosal blood vessels, leaving a broader base for the flap relative to the coronal flap edge.

Anatomical Considerations for Flap Design

The location of critical anatomical structures must be taken into account when designing a periodontal flap. In the posterior region of the mandible, the mental foramen and associated neurovascular bundle should be protected during flap elevation and tissue retraction. It is often identified on dental radiographs near the apex of the mandibular second premolar.[14][15] The lingual nerve vascular bundle passes near the pterygomandibular raphe and onto the third molar roots. It is the most likely nerve injured by inferior alveolar nerve blocks and can be damaged by the reflection of a lingual flap in the third molar region.[16] Vertical releases on the lingual side of the posterior mandible should be avoided.

Flaps in the maxilla must avoid damaging the greater palatine neurovascular bundle and the incisive papilla. The palate is typically used for connective tissue graft harvesting. The greater palatine bundle runs on the palate vault from posterior to anterior at a distance close to the alveolar ridge.[17] Injury to the greater palatine bundle is associated with prolonged bleeding and healing complications. The incisive papilla between the maxillary incisors contains soft tissue and a vestigial nerve in adults. It can be cut and elevated if needed, allowing the incisive canal's contents to be removed for grafting.

Indications

Periodontal Surgery For Pocket Reduction

Periodontal surgery is the indicated management option for residual deep pockets after non-surgical therapy for teeth with a prognosis other than "hopeless" and in cases where periodontal therapy prognosis is "likely."[18][19] The indication for specific procedures varies with pocket type, as described below.

Gingivectomy

• Residual pocketing with excessively thick, fibrous gingival tissue but no underlying bone defect

Wedge Procedure

• Residual pocketing at a distal or mesial tooth surface that faces excessively thick gingival tissue
• Typically at the most distal tooth of the arch, adjacent to thick tissue of the maxillary tuberosity or the retromolar pad

Gingival Flap Procedure

• As monotherapy for suprabony pockets: residual pocketing without an underlying bone defect, surgery accesses root surfaces for calculus and dental biofilm removal
• As monotherapy for infrabony pockets associated with shallow bone defects in the anterior maxilla
• As part of regenerative therapy to provide surgical access to bone defects

Osseous Surgery

• As monotherapy for infrabony pockets associated with shallow bone defects or irregular bone contours
• Commonly as part of regenerative therapy to provide surgical access to bone defects and improve bone defect morphology

Bone grafting, Guided Tissue Regeneration, Biologics, or Combinations of these:

• Infrabony pockets with deep bone defects; bone defects should be favorable to regeneration

Periodontal Surgery for Restorative or Esthetic Purposes

Clinical Crown Lengthening

Primary indication: subgingival caries, coronal fracture, or restorative margin that cannot be restored with standard restorative procedures for tooth isolation and restoration. The tooth must be otherwise restorable.

Teeth undergoing crown lengthening and adjacent teeth must meet the following requirements:

• Bone removal can expose sufficient sound tooth structure to allow restoration:
  • Bone removal allows the preparation of axial walls that are at least 4 mm long
  • Bone removal permits enough occlusal reduction for minimal restorative material thickness
  • For root-canal treated teeth, bone removal allows the preparation of 1 mm ferrule
  • Bone removal creates sufficient space for soft tissue attachment and a minimal sulcus (average 3 mm)
• Long enough bone-supported root structure to permit a few millimeters of bone removal without resulting in a poor crown: root ratio or tooth mobility
• Bone removal does not expose nearby furcation entrances.
• Longer tooth appearance and gingival recession do not pose a significant aesthetic concern.

Crown Exposure

• Altered passive eruption ("gummy smile") with bone approximating or covering the cementoenamel junction, resulting in an excess gingival display; no restoration is needed

Gingivectomy

• Altered passive eruption ("gummy smile") with excess gingiva covering tooth but crestal bone remaining 2 mm apical to the cementoenamel junction
• Removal of genetic or medication-induced gingival enlargement
• Removal of pigmented gingiva (racial pigmentation tends to return long-term)

Periodontal Surgery for Mucogingival Defects

Free/Autogenous Gingival Grafts

• Correction of mucogingival defects or gain in keratinized gingiva
• Localized deepening of the vestibule

Lateral Sliding / Pedicle Flap

• Correction of single localized gingival recession or mucogingival defect with a normal amount of keratinized gingiva adjacent to the defect

Connective Tissue Grafts and Acellular Dermal Matrix Grafts

• Gingival recession defects
• Increase gingival or mucosal tissue thickness

Contraindications

Absolute dental contraindications include a hopeless dentition that is better treated with tooth removal and complete denture therapy. A hopeless dentition usually features more than two-thirds bone loss at most teeth, including canines and first molars, or significant generalized tooth mobility.

Relative contraindications include patient factors that may compromise treatment outcomes or increase the likelihood of complications. Tobacco smoking is linked to a less successful reduction of probing depths and attachment gain after periodontal surgery and usually results in more significant gingival recession.[20] Diabetes mellitus is associated with a higher risk of postoperative complications such as increased swelling, flap dehiscence, and delayed wound healing.[21] Immunosuppressive medications and conditions may increase the risk of postoperative infections. Medications that interfere with angiogenesis and bone resorption may pose a risk of jaw osteonecrosis, although the specific postoperative risk is unknown. The risk is likely small but not zero in patients taking oral bisphosphonates and more significant in patients who have received intravenous bisphosphonates for cancer treatment. However, patients with medical conditions including diabetes, cardiovascular disease, coagulopathies, and immunosuppression such as HIV can undergo periodontal surgery, provided that glucose levels, cardiovascular function, and relevant laboratory parameters are within safe limits. 

While not precluding periodontal surgery, age could negatively affect treatment as tissue fibroblasts exhibit increasing senescence, and wound healing is slower. This may increase the risk of tissue tears during surgery and bruising from increased blood vessel fragility. 

For periodontal pocket reduction surgery, several local factors may reduce chances of regeneration, attachment gain, and pocket reduction, including root proximity, tipping or rotation of teeth, tooth mobility, thin mucosal tissue, the orientation of furcation entrances, enamel pearls, cervical enamel projections, denticles, ridges, root groves, and impacted teeth.

Crown lengthening may not be possible if restorative margins extend into furcations or result in excessive bone removal. Crown exposure is not indicated in excessive gingival display caused by hyperactive lip muscles, skeletal maxillary excess, or a short upper lip.

Free gingival and autogenous connective tissue grafting may be challenging if the palatal vault is shallow, contains a palatal torus, or features thin palatal tissue. Pedicle flaps are challenging to perform for broad gingival defects and are unlikely to succeed if adjacent gingival tissues are limited.

Preparation

A preprocedural antiseptic rinse may reduce viral and bacterial load in the aerosol generated by ultrasonic and rotary instrumentation.[22] Patients with dental anxiety may benefit from anxiolytic measures ranging from nitrous oxide inhalation to preprocedural oral anxiolytics (ie, 0.125 mg triazolam 1 hour before the procedure) to oral sedation, intravenous sedation, and general anesthesia. 

Generally, periodontal surgery can be performed using standard local anesthesia techniques with typical dental anesthetics such as 2% lidocaine/1:100,000 epinephrine. Two percent lidocaine/1:50,000 epinephrine administered locally just before incisions can be helpful to control bleeding during flap incision and elevation. Long-lasting anesthetics such as bupivacaine can be used immediately after surgery for improved pain control and to reduce the need for analgesic medication. Periodontal surgery personnel may choose to prescribe preemptive non-steroidal anti-inflammatory drugs (NSAIDs) for pain control and antibiotic prophylaxis in patients at risk for infections. Similarly, dexamethasone may be prescribed to reduce postoperative swelling and swelling-related postoperative pain if bone graft materials or biologics containing growth factors are used.

Technique or Treatment

Procedures with a Focus on Removing Gingival Tissue

Gingivectomy

Gingivectomy is often performed when residual pockets are associated with excessively thick gingiva with no underlying bone defect. This is often the case with pseudopockets resulting from altered tooth eruption, genetic causes, or medications (drug-induced gingival overgrowth). However, gingivectomy is limited in most pocket reduction scenarios as it does not address bony defects, and pocketing from enlarged gingival tissue usually recurs. Gingivectomy procedures can also remove pigmented gingiva, but pigmentation may return over time.[23][24] (see Box 1.1)

Wedge Procedure

Another excisional procedure is the proximal or distal wedge procedure. It is employed when pocketing is confined to a distal or mesial tooth surface that faces thick gingival tissue, like the maxillary tuberosity, retromolar pad, or an edentulous area. For a wedge procedure, there must be no underlying bone defect. The thickest part of the tissue is excised with a square or wedge-shaped incision of converging cuts. The pyramid-shaped piece of the gingiva is removed, and the edges are sutured together. (see Box 1.2)

Procedures with a Focus on Accessing Root Surfaces

Gingival Flap Procedures

Gingival flap procedures are typically employed when there is residual pocketing without an underlying bone defect, except for generalized bone loss as in suprabony pockets. Alternative names for gingival flap procedures are "open flap debridement" or "surgical scaling and root planing." Widman was one of the first surgeons to describe a gingival flap for pocket reduction.[27] (see Box 2)

Personnel may opt for other incision designs, instruments, and suturing techniques based on treatment goals, personal preference, and local anatomy. Variants of the gingival flap procedure differ by the number of incisions, locations of the incisions, and extent of the reflection of the flap. A notable variant is the modified Widman flap, which uses sulcular, submarginal, and connecting incisions for minimal tissue reflection and removal, resulting in minimal gingival recession. The improvement in attachment and probing depth is most likely due to the formation of a junctional epithelium.[28] 

The modified Widman flap is frequently used as a control treatment in clinical trials of periodontal surgery techniques. It differs from a conventional gingival flap in that incisions are kept close to the root surface, and tissue is only reflected enough to allow access to the root surface. Conceptually, the opposite of a modified Widman flap is the apically positioned flap, which features much flap reflection and suturing of the flap margins apical to the alveolar crest by suturing it to the vestibular periosteum. The apically positioned flap may be used with osseous surgery to achieve minimal interdental thickness and maximized probing depth reduction. Unlike the modified Widman flap, the apically positioned flap is associated with significant generalized gingival recession.

Procedures with an Added Focus on Achieving Physiologic Bone Contours

Osseous Surgery

Osseous surgery procedures are performed when there is residual pocketing with shallow localized bone defects, as in infrabony pockets. It is the additional step of removing or reshaping alveolar bone after flap reflection. Osseous surgery typically results in a significant reduction in probing depth in pockets greater than 4 mm.[29][30] However, exposed root surfaces can cause considerable gingival recession and dentinal hypersensitivity.[31] Due to the inevitable gingival recession, it is usually avoided in the anterior maxilla. Osseous surgery represents a resective approach by strategically removing the walls of bone defects and restoring a positive bony architecture. Interproximal and furcation bone levels are more coronal than the bone margin on the roots' facial or lingual side. Osseous surgery alone is not recommended for deep localized bone defects (greater than 3 mm).[32] In such cases, teeth are either extracted or treated with regenerative surgery.

After reflecting a full-thickness flap and performing root surface debridement as in gingival flap surgery, the bone is selectively removed to create a positive or flat bony architecture. Generally, defect walls are removed from the lingual side for mandibular and maxillary teeth to preserve the buccal bone and minimize interproximal gingival recession post-surgery.[33][34] A common technique involves removing bony shelves and exostoses first with round surgical burs in a process called osteoplasty. Then, using surgical end-cutting burs, bone is removed towards the lingual side to the depth of the interproximal bone defect. This is followed by bone removal to establish the desired bone level on the mid-facial and mid-lingual sides, resulting in a positive architecture. A surgical round bur is then used to connect the marked bone levels and create a positive architecture. Finally, flame-shaped burs, chisels, and bone files are used to create smooth bone surfaces interproximally. Once bone removal is complete, various suturing techniques, such as inverting mattress sutures, can be employed to closely adapt the flaps to the underlying bone and minimize interproximal tissue thickness. (see Box 3)

A variant of osseous surgery is fiber retention osseous resective surgery, where instead of a full-thickness flap, a split-thickness flap is used to preserve attachment fibers on root surfaces before conservative bone removal.[35] This technique results in similar pocket depth reduction but less gingival recession and dentinal hypersensitivity.[36]

Procedures that Aim to Regenerate Lost Periodontal Tissues

Bone grafts, Guide Tissue Regeneration, and Biologics

Regenerative procedures, including bone grafting, guided tissue regeneration, and biologics, can be implemented to promote the regrowth of lost bone, periodontal ligament, and cementum in residual pockets with deep localized bone defects. Regenerative approaches can fill bone defects, increase clinical attachment, and reduce pockets and gingival recession. However, regeneration success depends on surgeon experience, defect morphology, root surface abnormalities, flap thickness, tobacco use, and medical conditions like diabetes mellitus.[37] In cases where the defect morphology or patient characteristics are unfavorable, surgeons may choose to extract teeth or opt for osseous surgery instead.

In general, regenerative procedures are performed after raising a gingival flap and reshaping the bone to improve the morphology of deep bone defects. Regenerative materials, individually or in combination, are applied to deep bone defects after debriding the defects from soft tissue but preserving any healthy periodontium on the root surfaces. For example, after preparing the defects, surgeons may apply biologics such as an enamel matrix derivative, which involves using a root surface conditioning gel followed by a gel containing an enamel matrix derivative. Additionally, surgeons may loosely place bone graft particles from nearby autogenous donor sites, use allografts, xenografts, or alloplastic sources, or apply engineered bone grafting materials such as bone putty into the defects. Furthermore, the defect may be covered with barrier materials designed for guided tissue regeneration. Each regenerative procedure involving biological preparations requires a different technique. The basic stages of allograft or xenograft placement are described in box 4.

A wide range of bone graft materials can be utilized, including autogenous bone, ranging from cortical bone chips harvested from the alveolar cortex adjacent to the defect to the iliac bone.[38][39] In countries with established tissue banking infrastructure, like the U.S., particulate allograft materials are commonly used. In the absence of tissue banks or when the patient does not want allograft materials, xenograft materials derived from non-human species, such as sintered bovine particulate bone or alloplastic materials derived from minerals such as beta-tricalcium phosphate, may be used instead. Autogenous, allograft, xenograft, and alloplastic materials produce similar favorable outcomes. However, histologic regeneration only uses autogenous and demineralized freeze-dried bone allografts.[40]

Biologics used in periodontal regeneration include enamel matrix derivatives.[41] Other biologics are recombinant human platelet-derived growth factors (rhPDGF-BB) and fibroblast growth factors (rhFGF-2).[42][43] Biologics include various autologous platelet concentrates such as platelet-rich plasma (PRP), platelet-rich fibrin variants (PRF, I-PRF, L-PRF, A-PRF), PRF pressed into membranes, and sticky bone.[44][45][46][47][48][49]

Various guided tissue regeneration membranes, both resorbable and non-resorbable, exist, with different chemistries controlling the resorption rate. Resorbable and non-resorbable membranes produce similar long-term improvements in probing depth and attachment levels.[50] Non-resorbable membranes require a second surgery for retrieval, which may make them less preferable.[51] Regenerative treatment with membranes has a higher complication rate than treatment with enamel matrix derivative, such as membrane exposure.[52]

Periodontal Surgery for Restorative and Aesthetics Purposes

Clinical Crown Lengthening

Clinical crown lengthening is most commonly used to save teeth with subgingival caries or coronal fractures that extend below the gingival margin in an otherwise periodontally healthy environment.[53] It can also increase the available tooth structure for endodontic treatment and ferrule preparation. The procedure aims to reestablish enough space for supracrestal tissue to re-attach to the root surface coronal to the underlying crestal bone. Violating the space for supracrestal attached bone may lead to chronic gingival inflammation and gingiva recession.[54] It is possible that several months after the clinical crown lengthening, the gingival margin creeps coronally, which may trigger inflammation if a restoration is placed too soon after surgery or if the margin is extended too close to the crestal bone.[55] (see Box 5)

Crown lengthening should not be done if bone removal around teeth results in exposure to furcation entrances. Since crown lengthening uses osseous surgery techniques of bone removal and aims to achieve positive bony architecture at a more apical level, the crown-lengthened tooth and adjacent teeth will exhibit signs of gingival recession after the surgery has healed. Bone removal around the targeted tooth should allow sufficient space for the soft tissue attachment between crestal bone and a minimal sulcus of about 1 mm apical to the restoration.

Biologic shaping is a variant of clinical crown lengthening that involves using specific burs to reshape teeth with conservative bone removal after raising a split-thickness flap and letting gingiva attach to clean dentin surfaces during healing. The goal is to produce a tooth preparation that is easier to restore and maintain long-term. Biologic shaping eliminates Glickman class I and II furcation involvement through flattened tooth profiles and fluted crowns.[56][57] While biologic shaping can also eliminate furcation involvement, restoration is always necessary, and root surfaces of vital teeth need to be treated with desensitizing agents to prevent sensitivity during the healing process.

Crown Exposure

Crown exposure is similar to crown lengthening, but it is done in a healthy environment where restoration is unnecessary, and the goal is to expose the anatomic crown fully. Typically, this procedure is done in the anterior maxilla for improved aesthetics in cases of a gummy smile caused by the altered passive eruption. In altered passive eruption, alveolar bone encroaches or covers the cementoenamel junction after complete facial growth.[54] This procedure is also known as aesthetic crown lengthening. For aesthetic crown lengthening, the Chu proportion gauge and laboratory-fabricated surgery guides can help guide bone removal for improved outcomes.[58][59]

Periodontal Surgery for the Treatment of Mucogingival Defects

Free/Autogenous Gingival Grafts

Localized defects of gingiva can be predictably treated with a free gingival autograft procedure.[60] This involves transplanting a block of gingiva containing basal epithelium from a donor site to the deficient recipient site. Free gingival grafts may shrink up to 48% in the months after placement, depending on surgical factors such as the thickness of the harvested tissue.[61] The color of the grafted tissue often does not match the surrounding tissue, resulting in a patch-like appearance.[62] Therefore, free gingival grafts are generally avoided in the anterior maxilla and other obvious areas. Patients may experience significant pain, swelling, and bleeding from harvesting palatal tissue, which can be reduced by applying platelet-rich fibrin (PRF), cyanoacrylate, or hemostatic sponges.[63] Using a tight-fitting rigid palatal stent or propylene mesh to cover the donor site can help reduce bleeding and pain.[64]

The gingival graft procedure typically involves creating a split-thickness envelope flap along the mucogingival junction at the recipient site. This leaves a thick layer of periosteum and creates a soft tissue pouch large enough to accommodate the free gingival graft. Denuding adjacent gingiva of the epithelium may improve color blending between the graft and surrounding tissues. The free gingival graft is usually harvested from the palate, several millimeters from the gingival margin of the premolars, and at a safe distance from the greater palatine neurovascular bundle. Harvesting can be done with a scalpel, using a split-thickness incision to outline the desired graft and dissecting it off the palate through the lamina propria. Alternatively, palatal graft harvesters can be used to obtain strips of palatal gingiva. Cyanoacrylate, collagen tape, wound dressing, suturing, meshes, or a palatal stent can be applied to induce hemostasis at the donor site. After removing adipose and glandular tissue, the gingival graft is fixed onto the periosteum of the recipient site using simple interrupted and mattress sutures with small suture sizes (ie, 5-0 or 6-0).

Most gingival grafting procedures follow similar principles (see Box 6.1), with variations limited to alternative donor sites like the maxillary tuberosity, different surgical instruments, partial de-epithelialization of the graft, or variation in shape.[65][66][67] A notable variant is the gingival unit transfer graft, where the harvested graft contains interdental and marginal epithelium.[68] While gingival grafts often reduce adjacent gingival recession defects through coronal migration of the gingival margin, a recent review suggested that gingival unit transfer graft may have a greater potential to resolve gingival recession.[69]

Lateral Sliding/Pedicle Flap

Small, localized defects of keratinized gingiva adjacent to a broader area of gingiva can be treated with a lateral sliding pedicle flap, where adjacent tissue is mobilized with a split-thickness incision and advanced over the defect site onto denuded gingiva.[70] In cases of narrowly attached gingiva, a modified apically positioned flap can be employed to split the attached gingiva and apically position the flap's apical side, thus gaining gingiva through secondary intention healing.[71] (see Box 6.2)

Connective Tissue Grafts and Acellular Dermal Matrix Grafts

Localized gingival recession limited to the facial or lingual surfaces, without adjacent interproximal attachment loss, can be predictably corrected with autogenous connective tissue grafting.[60] Connective tissue autografts are a common method for correcting such defects. In this procedure, a piece of connective tissue is harvested, usually from the palate, and inserted into a split-thickness flap surrounding the recession area. There are various variations of this procedure, depending on the harvesting technique, the location of the harvest, the recipient site preparation, and the graft application. Typically, recession treatment results in significant root coverage or complete coverage in Cairo RT-1 type defects, partial gain in Cairo RT-2 type defects, and no predictable gain in Cairo RT-3 defects.[72] While there are many variations, the basic steps for a subepithelial connective tissue graft after anesthetizing donor and recipient sites are described in Box 6.3.

Instead of splitting a free gingival graft to obtain a subepithelial connective tissue graft, surgeons may choose to obtain a connective tissue graft with a single incision from the palate, as described by Hürzeler and Weng. This technique can limit the amount of bleeding and pain from the donor site after grafting.[73] A closely related procedure is the acellular dermal matrix graft, which uses the same recipient site creation techniques but employs a thick membrane-like sheet of the allogeneic dermal matrix instead of connective tissue. The benefit of the allograft procedure is the absence of pain, bleeding, and swelling from the donor site. Another alternative is tunneling techniques, where the connective tissue graft is inserted into a surgically created tunnel through the papilla, a mucosal incision (ie, VISTA), or a small mucosal hole (ie, Pinhole^®).[74][75][76]

While connective tissue grafting or acellular dermal matrix grafts are typically used for treating localized recession defects, other procedures can also treat localized recession defects. Single localized gingival recession adjacent to a wide keratinized gingiva can be treated with a lateral sliding flap or a double pedicle flap. These techniques avoid donor site surgery and provide excellent color match while increasing the amount of keratinized tissue. The main limitation of these procedures is that case selection and surgical technique are critical to the success of these procedures. The coronally advanced flap is another method for resolving moderate or shallow localized recession defects on multiple teeth. However, the coronally advanced flap by itself is less effective than the coronally advanced flap combined with a connective tissue graft or collagen matrix.[77] The coronally advanced flap is typically used as a control procedure in clinical trials evaluating various surgery techniques and materials for treating gingival recession defects.[78]

Complications

Complications of periodontal surgery can be categorized into two groups: those common to any oral surgical procedure and those specific to periodontal surgery.

General Postoperative Complications After Periodontal Surgery

Like any oral surgical procedure, periodontal surgery can result in postoperative bleeding, pain, swelling, tissue discoloration, and bruising. Although no studies have directly compared the postoperative experiences of periodontal surgery to other oral surgical procedures such as tooth extractions, it is generally expected that common periodontal pocket reduction surgeries and crown lengthening surgeries would cause less postoperative pain, bleeding, and tissue swelling than tooth extractions. This is because these procedures typically reposition tissue flaps for primary intention healing. For mucogingival surgeries, the donor site (typically the palate) usually experiences more significant pain, swelling, and bleeding than the recipient site in free gingival grafting. In a large retrospective study of surgeries performed at a large academic periodontal clinic, postoperative complications were uncommon, with dentinal hypersensitivity (5.7%), excessive pain (4.1%), and postoperative bleeding (3.5%) occurring most often.[21].

In most cases, postoperative pain resulting from periodontal surgery can be managed with short-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or dexamethasone.[79] Cold pack application, periodontal dressing, or surgical stents may also help with pain control after surgery. Preemptive analgesia may reduce pain after periodontal surgeries. Pain is typically most intense 5 to 6 hours after surgery. For moderate to severe pain after periodontal surgery, a combination therapy of ibuprofen 400 to 600 mg and acetaminophen 500 mg every 6 hours has been suggested.[80]

Intraoperative blood loss from periodontal surgery averages about 37 mL.[81] Bleeding typically stops after reapproximation of flaps, and significant postoperative bleeding has only been reported in individuals taking anticoagulant medications. Local hemostatic measures are usually effective in stopping postoperative bleeding. Consequently, severe bleeding after periodontal surgery is rare in the general population, and postoperative bleeding concerns are typically limited to those with severe genetic or acquired bleeding conditions such as hemophilia or coumadin therapy.[82]

Postoperative infections following periodontal surgery are rare, with a reported prevalence of 2%.[83] Antibiotic coverage is generally not necessary after gingival flap surgery, osseous surgery, pedicle flap surgery, or connective and free gingival graft surgery. Antibiotics are typically prescribed after bone grafting and guided tissue regeneration procedures, but the optimal duration of antibiotic therapy for these surgeries lacks consensus or evidence. Generally, patients who use tobacco or have uncontrolled diabetes mellitus are considered to have a higher risk for postoperative infections. Individuals with a history of bisphosphonates and other anti-angiogenic medications are likely at similar risk for medication-related osteonecrosis of the jaw as with extractions, although no data is available.

Specific Postoperative Complications

Pocket Reduction Surgeries

Complications specific to periodontal surgery include the possibility that the surgery may not achieve the desired outcome and the unique risks associated with each type of periodontal surgery. Pocket depth reduction surgeries typically result in some degree of gingival recession, leading to a longer appearance of the teeth and exposed root surfaces.

Teeth with exposed root surfaces may develop dentinal hypersensitivity, causing sharp pain in response to cold, hot, or highly osmotic foods. While minor tooth sensitivity is common after most dental procedures, sensitivity after periodontal surgery can be pronounced and may require intervention. Treatment options for dentinal hypersensitivity include over-the-counter and in-office desensitizing agents, the application of sealants, or, in severe cases, root canal therapy.

Gingival recession may also prevent the complete filling of interdental spaces, resulting in unattractive open spaces known as black triangles. In cases of free gingival grafting surgery, the grafted areas may have a different color, leading to poor gingival esthetics. After the gingival recession, exposed root surfaces are also more susceptible to root caries, especially without effective oral hygiene practices. Pocket reduction surgery, particularly osseous surgery involving removing supporting bone in teeth already affected by significant bone loss, may increase tooth mobility. However, tooth mobility often improves during the healing process, as the gingival attachment, which contributes significantly to tooth support in severe periodontitis, is reestablished during periodontal surgery.

Crown Lengthening Surgeries

Teeth that have undergone crown lengthening surgeries will appear longer than before, and the interdental papilla will no longer reach the original interproximal contact. Therefore, restorations must account for these changes by having longer interproximal contacts. Teeth undergoing crown lengthening surgery must also be provisionalized for at least 6 weeks after crown lengthening. Patients must be instructed on how to perform oral hygiene for provisional restorations and prevent accidental fracture or dislodgment of provisional restorations. Since crown lengthening removes crestal bone and available bone height to vital structures, in rare cases, crown lengthening may preclude future implant therapy as there may no longer be enough bone for the placement of implants. In the anterior maxilla, crown lengthening of teeth on one side may require matching crown lengthening on the other side to achieve an esthetic result.

Mucogingival Procedures

Traditional free gingival grafts produce tissue changes during healing that concern patients as the graft may slough partially, be covered in yellow fibrin debris, and undergo drastic color changes during revascularization. Connective tissue grafts and other procedures also exhibit this trait but to a lesser degree. Free gingival grafts often appear as thicker and paler tissue patches once healing is complete. Patients may find the tissue defect from palatal harvesting disconcerting until it fills in with tissue. Occasionally, patients may experience an altered mouth feel as the palatal donor site may not heal back to the original shape, or the change in vestibular depth at recipient sites may feel different.

Clinical Significance

Periodontal treatment, including periodontal surgery, reduces the rates of tooth loss.[84][85] After 5 years or longer, desired clinical outcomes such as probing depth reduction and prevention of further attachment loss converge to similar levels for meticulously maintained patients after non-surgical and surgical therapies.[86] 

Periodontal surgery should be performed after initial scaling and root planing as it will significantly reduce probing depth and attachment level gain more than periodontal surgery without initial scaling and root planing.[87]

Pockets with depths of 7 mm show the most significant pocket depth reduction with periodontal surgery but also greater gingival recession than scaling and root planing.[30] Pocket depth reduction is similar for gingival flap and osseous surgery for pockets greater than 7 mm, but osseous surgery produces more gingival recession.[88] Regenerative periodontal therapy for infrabony pockets generally results in attachment gain and radiographic bone fill, with deeper and more narrowed angled bone defects favoring regeneration. Regeneration is typically similar to any regenerative material.[89]

Enhancing Healthcare Team Outcomes

Patient outcomes after periodontal surgery are enhanced in a team setting. Drawing from recent recommendations for safety in dental implant placement, a surgery with a higher risk profile than periodontal surgery, patient safety may be enhanced by surgeons' and dental assistants' adoption of a safety culture. Similarly, patient safety may be improved by encouraging error reporting, using cross-checks, adherence to checklists, minimizing distractions, clear communication, and using standardized and simplified protocols.[90]

Comprehensive periodontal therapy, which may include periodontal surgery, has been shown to have beneficial effects on conditions such as type 2 diabetes mellitus and rheumatoid arthritis. There is good evidence that periodontal therapy generally improves HbA1c levels in individuals with type 2 diabetes by approximately 0.5%, independent of other interventions.[91] Moreover, periodontal treatment has been found to improve disease activity scores (DAS28) in individuals with rheumatoid arthritis.[92] Periodontal treatment also leads to improved endothelial function and enhanced atherosclerotic disease markers.[93]

Regarding the provision of periodontal surgery, while dentists can undergo training to perform such procedures, it is common for dentists to refer patients with a significant periodontal disease requiring surgical treatment to specialists. These specialists may include periodontists in countries offering postdoctoral education in periodontics or oral surgeons who provide periodontal surgeries in countries without a distinct education track. Treatment outcomes, including tooth survival, depend on timely referral.[94] Therefore, specialist associations, such as the American Academy of Periodontology, have published guidelines on when to refer patients to a periodontal specialist. Typically, patients with moderate to severe periodontal disease, unusual disease patterns, or complex medical histories are recommended to be evaluated by a periodontal specialist.[95] Clear communication and teamwork are essential for successful referral, as many issues, such as length of periodontal treatment and unexpected outcomes, can derail the referral process.[96]

In most cases, general dentists initiate the treatment of periodontal disease and provide restorative care. They may then refer patients with residual pockets or unresolved periodontal treatment needs to specialists. After completion of periodontal therapy, periodontists and general dentists may alternate in providing periodontal maintenance visits, or a patient may continue to receive maintenance care within a periodontal practice if there is a high risk of periodontal disease recurrence.