Periodontal regeneration using connective tissue graft wall and xenograft with coronally advanced flap in noncontained intrabony defects: A novel combination technique.

The present case report describes the novel combination of connective tissue graft (CTG) wall technique with xenograft for periodontal regeneration of extensive intrabony defects in the esthetic area. A 24-year-old female patient presented with gingival recession with mesial and distal deep bony defects at the upper lateral incisor and probing depths (PDs) of 7 and 5 mm, respectively. The surgical technique involved split-thickness buccal flap elevation, grafting the bone defects with xenograft bone substitute, securing the CTG over the surgical site followed by flap advancement. Uneventful healing was evident with reduction in PDs (5 and 4 mm), recession depths, and improvement in clinical attachment levels after 1 year. Radiographically, bone fill in the intrabony component was evident. It can be concluded that the presented approach combines the benefits of bone substitute's space maintaining and osteoconduction properties with the advantages of CTG wall to support the regeneration site and the overlying flap for improved clinical and radiographic outcomes in deep intrabony defects. Copyright:

INTRODUCTION

Periodontitis is a destructive inflammation of the periodontal apparatus that ultimately leads to hard- and soft-tissue losses. As a consequence, the support for teeth is jeopardized and, in turn, it can negatively affect esthetics, function, and their long-term prognosis.[1] Regenerative interventions pursue the ultimate goal of regaining lost periodontal structure in both form and function. Several approaches have been investigated for their regenerative capabilities in intrabony defects such as guided tissue regeneration (GTR), various grafting materials, enamel matrix derivative (EMD), flap operations, platelet-rich products, or a combination of two or more techniques. The biological and surgical approaches for successful regenerative interventions depend on many variables such as defect depth and width, number of remaining bony walls, soft-tissue deficiency, flap tension, and esthetic requirements.[23]

Connective tissue graft (CTG) wall technique for the treatment of intrabony defects has been suggested to reduce the recession incidence and regenerative site exposure, especially when optimal esthetic outcome is desired.[4] The rationale of utilizing CTG for osseous defects is to provide for a dense connective tissue barrier to support the healing site and also to increase the overlying flap stability for improved regenerative and esthetic results.[4] The original technique involved the delivery of EMD to the bone defect which is confined by its walls and the CTG. However, due to the gelatinous nature of EMD, it lacks space provision and self-supporting abilities, and hence, it is not suitable for wide noncontained defects as such.[56] The present case report describes a novel combination technique where xenograft bone substitute was utilized along with CTG wall technique for the regeneration of extensive combined two-walled intrabony defects to provide support for blood clot and osteoconduction in regenerative tissues as well as to prevent the collapse of the overlying CTG into bony defects.

CASE REPORT

A 24-year-old female patient was referred to the clinic of periodontology with the complaint of unesthetic “elongated” appearance and migration of the upper left lateral incisor and expressed the fear of losing it. The patient reported being nonsmoker. There were not any systemic conditions contradicting dental treatment. Furthermore, the patient reported no history of any periodontal surgeries. On examination, the tooth exhibited deep mesial and distal pockets, slight extrusion, mesial diastema formation, and slight mobility. Otherwise, the heights of interdental papilla as well as keratinized tissue height were adequate. On the palatal side of the tooth, neither recession nor deep pockets were evident. Otherwise, adjacent teeth were periodontally healthy. Radiographic examination revealed deep angular intrabony defects mesially and distally to the affected tooth [Figure 1].

Figure 1

preoperative examination: (a) mesial probing of 7 mm; (b) distal probing of 5 mm; (c) palatal view showing adequate gingival level; and (d) preoperative radiograph with evidence of bone loss

With the patient's consent, periodontal therapy involved initial supra- and subgingival debridement using ultrasonic instruments and curettes. In addition, oral hygiene instructions were emphasized and chlorhexidine 0.12% mouthwash was prescribed as an adjunct twice daily for 2 weeks. After 6 weeks of follow-up, persistent deep probing depths (PDs) were evident. Probing of mesial and distal sites revealed deep pockets of 7 and 5 mm, respectively, with bleeding on probing, and a gingival margin below the cementoenamel junction (CEJ) by 2 mm mesially and buccally and 1 mm distally, and hence, initial clinical attachment level (CAL) corresponded to 9 mm mesially and 6 mm distally and regenerative intervention was planned.[7]

Surgical procedure was initiated by the administration of 4% articaine HCl with 1:100,000 epinephrine (Inibsa Dental, Spain) for local anesthesia. After a sulcular incision, a split-thickness buccal flap was elevated with horizontal incision extending 3 mm on both sides at the base of the interdental papilla. Two vertical incisions extending beyond the mucogingival junction and full-thickness elevation beyond defect were carried out to assist passive flap advancement. Palatal tissues were not elevated to act as soft-tissue support for the bony defects and bone substitute material. Instrumentation and debridement of the root surface up to the level of pathological dehiscence and the bone defects were carried out and granulation tissues were removed. Consequently, bony defects showed a compound 2–3-walled defect distally with vertical component of 4 mm, while mesially, it was a 2-walled 5-mm defect. The CTG was harvested from the palate using trapdoor incision technique[8] with dimensions of 10 by 12 mm to cover the bone defects mesiodistally and apicocoronally. The CTG was initially attached to the labially de-epithelialized anatomical papillae with two simple interrupted knots at the level of the CEJ using a 5-0 bioabsorbable polyglycolic acid suture (Egysorb, Taisier-Med, Egypt). The apical end of the CTG was rolled down to allow bone graft insertion; bovine xenograft particles (Hypro-Oss, Bioimplon GmbH, Germany) were packed into the defects, and then, two periosteal sutures were used to fix the CTG apically. Following that, flap advancement and suturing were accomplished using interrupted knots at the vertical incisions, followed by double-sling sutures to secure the flap margin against tooth surface and papillae with the abovementioned suture material [Figure 2].

Figure 2

Surgical steps: (a) flap elevation; (b) securing a connective tissue graft coronally; (c) insertion of xenograft bone substitute; and (d) flap advancement and suturing

The patient was instructed to avoid chewing, trauma, or brushing at the surgical sites. Chlorhexidine 0.12% mouthwash was prescribed twice daily for 4 weeks, after which toothbrushing was initiated using soft brush and gentle rolling from apical to coronal direction.[910] Sutures were removed 2 weeks postsurgically. Supportive periodontal therapy visits were carried out 3, 6, and 12 months. At the latest follow-up appointment at 1 year after the surgical intervention, clinical examination demonstrated adequate flap healing and gingival tissue integration, with reduced PDs corresponding to 3 and 4 mm, and improved gingival margins levels of 1 mm and 0 for the mesial and distal sites, respectively. CAL improved from 9 mm to 4 mm at the mesial site and from 6 mm to 4 mm at the distal site [Table 1]. No tooth mobility was noticed, but bleeding on probing was evident at the distal site. Radiographically, graft material fill was noticed at the 4-week radiograph, and bone maturation and fill of the intrabony defects were confirmed at the 1-year radiograph postoperatively [Figure 3].

Table 1

Baseline and final values of probing depth, recession depth, and clinical attachment level

	Mesial side		Distal side
	Baseline	12 months	Baseline	12 months
PD (mm)	7	3	5	4
REC (mm)	2	1	1	0
CAL (mm)	9	4	6	4

PD – Probing depth; REC – Recession depth; CAL – Clinical attachment level

Figure 3

postoperative follow up: (a) initial healing clinically after 1 month; (b) healing after 1 year; (c) radiographic bone defect fill after 1 month; and (d) radiograph after 1 year

DISCUSSION

In the present case, regenerative treatment at the intrabony defects with the combined use of xenograft and CTG barrier resulted in a pronounced bone fill that remained stable for 1 year. The technique also showed a reduction of probing and recession depths with an overall improvement of the CAL, good soft-tissue integration, and flap healing. Xenograft bone substitute was used to provide mechanical support and space provision to the blood clot and prevent the collapse of CTG wall into the extensive bony defects, in addition to its osteoconductive and regenerative properties confirmed histologically.[11] The bovine-derived xenograft, used in the current study, usually undergoes a multistage purification process to remove all organic components, leaving an anorganic crystalline hydroxyapatite bone mineral matrix that is biocompatible as well as both physically and chemically similar to human bone. The bone architecture after processing results in an interconnecting macro- and microporous arrangement that facilitates angiogenesis and the formation and ingrowth of new bone.[12]

Since esthetics was a prime concern for the patient, the CTG wall was deployed to serve two functions: one is to hold the graft material, and more specifically, to provide stability and support for the overlying flap for superior and more stable esthetic outcomes. In a study comparing single flap with and without CTG for the treatment of intrabony defects with buccal dehiscence, the adjunctive use of CTG resulted in better stability of the gingival level and an increase in keratinized tissue height and gingival thickness postoperatively.[13]

In the original CTG wall technique,[4] EMD was used as an adjunct for the regeneration of intrabony defects. However, since it is supplied as a gelatinous medium, it does not possess space provision ability, particularly in noncontained bony defects. In a study comparing the regenerative effect of GTR using titanium-reinforced membrane in contrast to EMD alone in noncontained bony defects, clinical results showed that CAL gain was almost doubled in the GTR group, and hence, it indicated that space provision was crucial for successful regeneration in these particular extensive defects.[14] In the present case, space maintenance was achieved using xenograft material, and despite the minor concern of placing soft-tissue grafts over avascular bone substitute bed, the present technique provided blood supply through the covering split-thickness flap and the lateral split-thickness connective tissue bed. The interdental papillae were kept in place without elevation since this helps preventing interdental tissue collapse and improving soft-tissue stability. Moreover, in the original CTG wall technique, the envelope coronally advanced flap (CAF) technique designated for treatment of multiple recession defects was deployed without using any vertical incisions.[14] However, in the present study, CAF with two vertical releasing incisions was done to flap advancement after application of bone substitutes, especially it has been proved that there is no difference between both techniques in terms of recession reduction and CAL gain.[15]

In the present case, an improvement in recession depth was achieved, but it was not totally corrected due to the fact that the tooth was extruded, the same observation as reported in the original CTW technique which was resolved through prosthetic masking using veneers.[14] In the present case, however, orthodontic intrusion or prosthetic correction was postponed by the patient due to financial reasons. In our case, it was also noticed that the mesial side had greater CAL gain than the distal side which may be attributed to the wider interdental space mesially that provided surgical accessibility and facilitated oral hygiene.

In summary, the present technique utilizing GTR with CTG wall and xenograft provides added benefits. On the one hand, bone substitute provides for osteoconduction, space maintaining, and blood clot stabilization abilities, and on the other hand, the CTG supports the regeneration site and the overlying flap and hence can be suggested for overall esthetic and functional success in deep noncontained intrabony defects in the esthetic area. Further research is needed to quantify the additional benefit of this combined therapy in comparison to established regenerative techniques.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This was a self-supported study.

Conflicts of interest

There are no conflicts of interest.