October 1, 2013
by Daniel Kobric, BSc, DMD, MSc (Perio), FRCD(C)
In the world of periodontics, as with any aspect in the practice of dentistry, we tend to treat specific problems, often one at a time. Periodontal issues encompass a wide variety of problems ranging from soft tissue loss and/or bone loss as a result of periodontal disease, extractions, orthodontic tooth movement, occlusion and implant therapy. Soft tissue defects, often referred to as mucogingival problems, such as inadequate or no attached gingiva, lack of keratinized tissue and recession are often managed via soft tissue grafting (autogenous or allograft/xenograft) with or without other Biomimetic agents such as Emdogain™ (Straumann®, Canada) or growth factors such as Gem 21 (Osteohealth®, Canada). Training courses tend to address management of specific problems individually, such as inadequate keratinized tissue/ recession or treatment of vertical defects. In “real life” however, day in and day out, the clinician faces cases where these entities present in combination. Hence the clinical decisions are more challenging and management depends on numerous factors, including patient wishes, biological determinants (vestibular depth, interproximal alveolar bone level, root prominence and/or proximity and tooth mobility) and existing or planned restorations.
The goal of soft tissue grafting procedures is to increase the amount of keratinized tissue and/or achieve root coverage. One of these methods includes the use of a free gingival graft (FGG) that can achieve root coverage with low predictability but can lead to increase in keratinization with high predictability. Root coverage and increasing tissue thickness can also be achieved via connective tissue grafting (CTG). In Miller 19851 suggested a classification system that included predictability of root coverage in contrast with the classification by Sullivan and Atkins2 that has no reference to surgical outcome.
The decision how to graft hard tissues depend the goal of the procedure: guided tissue regeneration (GTR) around teeth or guided bone regeneration (GBR) when no teeth are present. The purpose of grafting in the case presented below is an example for GTR. Results achieved from osseous grafting can vary and often reflect the initial clinical presentation and treatment method utilized. The size and location of the defect is of paramount importance: in narrow infrabony defects less than 4mm deep bone grafting is not indicated (Laurell L. et al3, Reynolds M.A. et al).4 Grafting of furcation defects is difficult and often unpredictable especially for large class II and class III defects (Murphy K.G. et al).5
This paper presents a “real life” case with explanation of the rationale behind the chosen method of treatment.
A 63-year-old healthy male was referred to the graduate periodontal clinic at the University of Toronto. The reason for referral was an 8mm pocket at the mesial of the mandibular right first molar (tooth 4.6). The patient had good overall health and fair oral hygiene and with the exception of plaque deposits observed at 4.6 and 4.3 with associated marginal gingival inflammation (Fig. 1). This includes the overt granulation tissue at the mesio-buccal line angle of lower right first molar and rolled gingival margins at the lower right canine. There was no attached gingiva at 4.6 and minimally attached gingiva at 4.3. The occlusion was characterized by bilateral group function within the confines of a premolar occlusion on the right side and molar occlusion on the left side. The patient indicated that there was no prosthetic device designed to replace the missing right maxillary teeth and it was the patient’s wish to save the existing and functional bridge. The teeth on the opposing arch (1.5,1.6 and 1.7) were lost due to severe caries rendering them non-restorable. A three-unit porcelain fused to metal (PFM) bridge extended from 4.6 to 4.4 and a class V restoration was present at 4.3. Both restorations were functional. Vitality testing by Endo-Ice showed that the teeth were vital. Probing depths at the 4.6 from at the distal buccal were 4, 7mm, and 8mm respectively with a class II buccal furcation. Bleeding upon probing was observed at both the 4.6 and 4.3.
The periapical radiographs showed radiolucency in the furcation and the area adjacent to the mesial root of 4.6. (Fig. 2) Generalized moderate horizontal bone loss was noted throughout the dentition.
The diagnosis of localized severe chronic periodontitis (4.6) with Miller class IV recession (4.6), Miller class I recession (4.4, 4.3) was assigned.
The patient was given the following options:
• Open flap debridement with osseous recontouring,
• GTR with the use of allograft bone and a non-resorbable membrane,
• Sectioning of the bridge, extraction of 46, alveolar ridge preservation (GBR) at 4.6 site and subsequent placement of implants at 46 and 45 to support PFM crowns for 4.6, 4.5, 4.3,
• Soft tissue grafting (FGG) at 4.6 and 4.3 to increase the amount of keratinized tissue (not for root coverage) and help with the patient’s oral hygiene management of the area.
The patient’s preference was to “keep his teeth and improve his gums”. He was informed that the option for hard tissue grafting was dependent on the nature of the bony defect as would be noted during the surgery. The choices for bone graft material were presented (allograft vs. xenograft) along with the pros and cons of each material. The patient consented to the use of the allograft material. He was also informed that the process to improve the clinical appearance would involve two surgeries. As such the soft tissue grafting would be done as a separate surgery after the hard tissue grafting. The subsequent soft tissue grafting procedure (FGG) was also explained at this time including risks of the procedure.
OPEN FLAP DEBRIDEMENT/OSSEOUS RESECTIVE SURGERY/BONE GRAFTING
Informed consent was obtained prior to the procedure. After adequate anesthesia was obtained, the root surfaces of the teeth on the fourth quadrant were scaled (hand and ultrasonic instrumentation) to remove plaque and calculus; a full thickness buccal muco-periosteal flap was raised extending from the distal aspect of 4.6 to the mesial aspect of 4.3. After reflection of the flap, granulation tissue was observed in the furcation of 4.6 and the area mesial to 4.6. Following debridement of the area, the extent of the bony defect was fully visualized (Fig. 3): a deep class II furcation defect and a two-wall infrabony defect at the mesial of 4.6. Osseous resective surgery was performed with rotary instruments along the buccal aspect of 4.6, under the 4.5 pontic and around the 4.4/4.3. Rotary instruments were also used on the root surfaces and on the mesial and lingual walls of the defect to remove remaining granulation tissues in the defect and to obtain a bleeding wound. The allograft material (cortical/ cancellous DFDBA, Straumann®) was hydrated in normal saline as per the manufacturers directions. The bone allograft was placed in the furcation and infrabony defects and covered with a non-resorbable membrane (Cytoplast™TXT-200, Osteogenics®). Interrupted 4-0 vicryl sutures (Ethicon®) were placed interproximally to position the full thickness flap. Suspensory vicryl sutures using the PFM bridge were used to stabilize the tissues at the desired level (Figs. 4 and 5). No dressing was placed. Amoxicillin was prescribed (500mg TID for 7 days) and patient was instructed to rinse the area with a 0.12 percent chlorhexidine twice a day to be started 24 hours after surgery. A prescription for Ibuprofen 800mg (TID x 4 days) was given for pain relief. He was seen for follow up at one and two weeks post-operatively (Figs. 5 and 6). At this time, the non-resorbable membrane became exposed but was left in place for an additional two weeks. The patient indicated that he used the pain medication for two days only. The patient wa
s instructed to use the chlorhexdine rinse on a cotton swab to be applied to the exposed membrane twice daily. One-month post-operatively the non-resorbable membrane was removed without the use of local anesthetic. At this time, granulation tissue had covered the wound fully and some bone graft particles were seen embedded in the soft tissue. The patient was advised to continue using the rinse once a day for an additional two weeks.
FREE GINGIVAL GRAFTING
Eight weeks after the GTR procedure (Fig. 7), the soft tissue portion of the treatment began. The procedure was reviewed with the patient and consent was obtained. After adequate anesthesia was obtained, local debridement of the recipient area was completed with hand instruments and ultrasonic scalers. Two recipient sites were then prepared: one at the 4.6 and at the 4.3 respectively. An isthmus of tissue soft tissue was left undisturbed in order to maintain adequate blood supply to the two adjacent grafts. A split thickness mucoperiosteal flap was raised using a 15 blade. The incision started at the disto-buccal line angle of the 46, through the sulcus, and anteriorely toward the 4.5 pontic site (Fig. 8). A fresh 15 blade was used to create a split thickness flap from the mesio-buccal line angle of 4.4 at the level of the mucogingival junction through the sulcus of 4.3 and toward the mesio-labial line angle of 4.2. A tin foil template was laid over the graft recipient sites and was then applied to the right side of the hard palate to outline the graft on the donor site. Then, a 15 blade was used to outline the shape of the template on the donor site and then the graft was harvested (Fig. 9). The graft was approximately 25 mm x 10 mm in dimensions with a thickness of between 1.5-2.5 mm. The gingival graft was placed on a moist sterile wooden tongue depressor and cut on a bias, which created two grafts of 15 mm in width (Fig. 10). Concurrently, gentle pressure was placed on the donor site and it was sutured with 4-0 chromic gut (Hu-Friedy®) in a “figure 8” configuration; Histoacryl (Tissueseal®) was applied to maintain hemostasis. Each graft was positioned at the coronal edge of the existing soft tissue. Root coverage was not attempted at either site. The grafts were sutured in place (Fig. 11) with a combination of 5-0 vicryl (Johnson & Johnson) and 4-0 chromic gut (Hu-Friedy®). No dressing was applied. The patient was given a prescription for chlorhexidine mouth rinse and antibiotics (Amoxicillin 500 mg q8h for one week). The patient still had pain medication from the previous procedure and declined another prescription. The sutures were removed 2 weeks after surgery. Figure 12 depicts the appearance of the site at three weeks post operatively. The patient was seen again 12 months after the soft tissue grafting (Fig. 13). The 4.6 and 4.3 each had an increased zone of keratinized tissue with less inflammation. Probing depths decreased, the furcation at the buccal of 4.6 had improved to a class I defect. The patient reported continued function with the bridge without pain or discomfort. A periapical film was taken (Fig. 14) clearly showed increased radiopacity at the furcation and around the mesial root suggestive of bone repair or regeneration.
Guided tissue regeneration (GTR) is defined as the re-growth of the periodontal supporting structures, namely, the periodontal ligament, alveolar bone and connective tissue attachment as defined by Melcher.6 If this does not occur, then only repair but not regeneration is achieved. In most clinical situations we cannot know the true outcome, as such determination would require extraction of the treated tooth and histology. However, what we see clinically following one year of healing is additional attachment loss (recession at 4.6,4.4 and 4.3), an increase in the presence of keratinized tissue, decreased probing depths and a reduction in inflammation clearly demonstrating clinical success (Fig. 13).
The bone grafting material used, demineralized cortical cancellous particulate bone (DFDBA), filled the defect. Its properties include the ability to be both osteoconductive and osteoinductive. The former being the ability to permit bone formation/growth and the latter being the ability of the already present growth factors to attract cells that promote bone growth. For a review please see Chapter 2, Dumitrescu.7
Over the years multiple soft tissue grafting materials have been introduced and documented in the literature. Nevins et. al.8 recently compared a xenograft to autogenous tissue in a gingival grafting pilot study. However, for the purpose of increasing the thickness of attached gingiva, the free gingival graft remains the gold standard. Coverage of the exposed root surface by gingival recession was not planned due to inadequate bony support for the soft tissues. The level of interproximal alveolar bone determines the level of soft tissue. Yet, given time and further healing of the alveolar defect to the mesial of tooth 4.6, it may be possible to coronally position the keratinized tissue to achieve a degree of root coverage. However, given the history at this site and what has been already achieved, this procedure was not planned.
The treatment provided in this case report offers one possible solution for this combined clinical situation. The specific hard and soft tissue grafting methods used fall within the scope of practice of periodontics and, in this case, provided a definitive treatment and resolution of the periodontal issues. In order to maintain a successful outcome, the practitioner must emphasize to the patient the importance of periodontal maintenance, including re-evaluation to monitor for signs of breakdown or re-occurrence. It is also important to inform the patient of each step of the surgery, including subsequent procedures that are planned as well as those that may be required if the goals of the initial surgery are not met. Every clinical situation is distinct and every case requires careful thought with respect to treatment options and patient considerations.
The author would like to thank Dr. Samuel Newman, Dr. Massey Safa, Dr. Jim Lai for their help with the clinical aspects and treatment of this case in the Graduate Periodontal Clinic, and Dr. Peter Birek for help with the manuscript.OH
Dr. Kobric maintains a private practice in Alliston, Ontario limited to periodontics and implant surgery. Dr. Kobric completed his MSc degree and specialty training in periodontology at the University of Toronto in 2012 and will be designated a Fellow of the Royal College of Dentists of Canada in Periodontology at the convocation ceremony in September 2013.
Oral Health welcomes this original article.
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2. Sullivan, H. C. and Atkins, J. H. “Free autogenous gingival grafts. I. Principles of successful grafting,” Periodontics, vol. 6, no. 3, pp. 121–129, 1968.
3. Laurell, L., Gottlow, J., Zybutz, M., Persson, R. Treatment of intrabony defects by different surgical procedures. A literature review. J Periodontol. 1998 Mar; 69(3):303-13.
4. Reynolds, M.A., Aichelmann-Reidy, M.E., Branch-Mays, G.L., Gunsolley, J.C. The efficacy of bone replacement grafts in the treatment of periodontal osseous defects. A systematic review. Ann Periodontol. 2003 Dec;8(1):227-65. Review.
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6. Melcher, A.H. On the repair potential of periodontal tissues. J Periodontol. 1976 47 (5): 256-260.
7. Dumitrescu, A.L. (2011). “Bone Grafts and bone graft substitutes in periodontal therapy” in
Chemicals in surgical periodontal therapy. Springer, New York.8. Nevins M, Nevins ML, Kim SW, Schupbach P, Kim DM. The use of mucograft collagen matrix to augment the zone of keratinized tissue around teeth: a pilot study. Int J Periodontics Restorative Dent. 2011; 31 (4): 367-73.