Long-Term Results of Grafting Using an ADM

The primary innovations in the treatment of GRDs have been in flap management and graft materials. Langer and Langer's technique used an SCTG and a coronally advanced flap (CAF) with vertical releasing incisions.² Raetzke developed an envelope technique that did not require vertical incisions but was indicated for use with an isolated GRD.⁴ Allen introduced the supraperiosteal envelope technique.⁵ This technique protects the integrity of the interdental papillae and allows for the treatment of multiple adjacent GRDs. In this technique, the SCTG is guided beneath the envelope through the space provided by a single tooth site. Zucchelli and colleagues described SCTG using a new surgical approach to the CAF.⁶ Their envelope design does not use vertical releasing incisions. In addition, the incisions made through the papillary area are positioned in a specific manner. A modified tunnel technique, developed by Mahn, was designed to overcome the difficulties in placing a large graft through the small access that is provided by a single tooth site.⁷ In this technique, vertical incisions placed on either side of the tunnel preparation enable easy placement of a large SCTG. This permits the treatment of multiple adjacent GRDs while minimizing the risk of damaging the interdental papillae. And finally, Zuhr and colleagues advanced the use of a microsurgical concept.⁸ By using microsurgical blades and suture material, wound healing and esthetic results could be improved.

The palate-derived SCTG has been used with a CAF for more than 30 years.² During that time, several alternative graft materials have been developed. The use of an acellular dermal matrix (ADM) was advanced by Harris.⁹ Henderson and colleagues described the use of an ADM with a tunnel technique to treat multiple adjacent GRDs.¹⁰ The use of a xenogenic (ie, porcine) collagen matrix with a CAF has been described for the treatment of GRDs¹¹ and to augment the zone of keratinized tissue around teeth.¹² Bovine pericardium collagen matrices have also been used as a substitute for SCTG.¹³ Enamel matrix derivatives, derived from porcine tooth buds, have been used with a CAF to treat GRDs,¹⁴ and more recently, the use of platelet-rich plasma with a tunnel technique has been described.¹⁵

Advancements in surgical techniques and graft materials have reduced treatment morbidity and improved esthetic results. Many reports describe short-term success; however, the ultimate goal of treatment is to realize long-term success. The following case report describes the successful use of an ADM to treat a Miller class I¹⁶ GRD. This article provides a 20-year update to the case, which was originally described as stable at 15 years in an article published in the October 2014 issue of Inside Dentistry.¹⁷

A 62-year-old male patient presented with the chief concern of progressive GRD affecting tooth No. 5 (Figure 1). The patient reported that the GRD had deteriorated within the last few years and that he delayed having it treated because he was concerned about the pain associated with a palatal donor site.

During examination, tooth No. 5 was found to have a 3-mm facial GRD. In addition, a narrow strip of composite was present at the cervical aspect of the facial surface, adjacent to the enamel. The straight facial probing depth was 3 mm, and there was a 1-mm zone of attached keratinized gingiva. After discussing the findings, treatment options, and risks with the patient, he agreed to have the GRD treated with connective tissue grafting using an ADM.

On the day of treatment, profound local anesthesia was obtained using 2% lidocaine with 1:100,000 epinephrine. A No. 15 scalpel blade (Bard-Parker^®, Aspen Surgical^®) was used to make intrasulcular incisions. A full-thickness flap was raised from tooth No. 4 to tooth No. 6 (Figure 2). Using hand curettes and a rotary, football-shaped diamond bur, the composite was removed from the facial aspect of tooth No. 5, and the root surfaces were planed until they were smooth and flattened. After an ADM was trimmed to approximately 10 mm by 6 mm, it was placed over the root surface and under the gingival flap, ensuring that the basement membrane side of the ADM was placed against the root surface (Figure 3). The gingival flap was then completely secured over the ADM and root surface using a continuous 4.0 plain gut suture (Figure 4).

At the 6-week reevaluation, the site was found to have healed well, exhibiting thicker gingiva and complete root coverage (Figure 5). The straight facial probing depth was 2 mm. The facial gingiva appeared thicker than it did prior to treatment, and a small amount of the enamel that was recontoured to remove the composite and reduce the tooth eminences could be seen. Residual incision line defects were also present in the adjacent interdental papillae.

At the 1-year reevaluation, tooth No. 5 continued to exhibit complete root coverage and natural gingival contours (Figure 6). The straight facial probing depth was 2 mm, and the facial zone of attached keratinized gingiva was approximately 2 mm. The incision line defects, which were present at the 6-week evaluation, were no longer visible. Tooth No. 5 had also been restored with a crown.

At the 15-year reevaluation, tooth No. 5 continued to exhibit complete root coverage (Figure 7). The straight facial probing depth was still 2 mm, and the facial zone of attached keratinized gingiva was still approximately 2 mm. The soft-tissue architecture of the facial gingiva and interdental papillae appeared healthy and natural in appearance. Since the 1-year reevaluation, tooth No. 4 had been restored with a crown as well.

Between the 6-week and 15-year reevaluations, the patient maintained 3- to 4-month periodontal recall and supportive therapy appointments, alternating between the general dentist's and periodontist's offices. After the 15-year reevaluation, the frequency was changed to 4-month intervals. The patient's oral hygiene varied but was typically fair with mild to moderate plaque accumulations. He smoked cigarettes, albeit infrequently, up to the 15-year reevaluation but quit soon after this appointment.

When the patient returned for a 20-year reevaluation (Figure 8), the crowns on teeth Nos. 4 and 5 that were present at the 15-year reevaluation were still in place. Tooth No. 5 continued to exhibit nearly complete root coverage, and the facial probing depth and facial zone of attached keratinized gingiva were unchanged.

In recent years, various reports describing the long-term outcomes of soft-tissue grafting have been published. Agudia and colleagues¹⁸ described 18- to 35-year results comparing GRDs treated with a free gingival graft with untreated contralateral homologous sites. They found that the use of a free gingival graft was successful in gaining root coverage and that these results remained stable for long-term periods. Untreated sites demonstrated a tendency toward progression of the existing GRDs.

Pini Prato and colleagues¹⁹ reported on the long-term outcomes of CAFs without the use of a graft material in the treatment of GRDs. Sites were evaluated during 1-, 5-, 10-, 15-, and 20-year postoperative visits. The researchers found that the mean root coverage of the treated sites decreased from 68.59% at 1 year to 56.11% at 20 years and that the percentage of sites exhibiting complete root coverage decreased from 34.02% to 25.00% during the same timeframe. They concluded that about half of the root coverage achieved with a CAF could be maintained for up to 20 years.

In a separate article, Pini Prato and colleagues²⁰ reported on the long-term outcomes of CAFs with the use of an SCTG in the treatment of GRDs. Sites were evaluated during 1-, 5-, 10-, 15-, and 20-year follow-up appointments. The mean root coverage of treated sites decreased from 74.23% at 1 year to 67.69% at 20 years. The researchers concluded that improvements achieved by an SCTG plus CAF during the short-term may be preserved long-term in the majority of treated sites. They also observed that teeth lacking a minimal 2-mm width of attached keratinized gingiva and presenting with noncarious cervical lesions were more prone to develop an apical shift in the gingival margin during a 20-year follow-up period.

Few studies describing the long-term treatment results of using an ADM have been published. Harris²¹ compared the treatment results of root coverage procedures using an ADM with those using an SCTG during both short-term (ie, 12.3 to 13.2 weeks) and long-term (ie, 48.1 to 49.2 months) periods. The mean root coverage values for procedures using ADM after a short term (93.4%), procedures using SCTG after a short term (96.6%), and procedures using SCTG after a long term (97.0%) were statistically similar; however, the mean root coverage value for procedures using ADM after a long term (65.8%) was statistically smaller. Over a long-term period, cases involving the treatment of multiple GRDs using an ADM had a mean root coverage of 70.8% whereas cases involving the treatment of a single GRD using an ADM had a mean root coverage of 50.0%. It was also noted that in 32.0% of the cases treated with an ADM, the results improved or remained stable over time.

Judging from the available evidence, the long-term results of the treatment of GRDs using a graft material appear to be more successful than the long-term results of untreated sites and those treated with a CAF alone.^18-21 Although the long-term results of treatments using an SCTG^19,20 appear to be better than those using an ADM,²¹ about one-third of the ADM cases in Harris's study did have good long-term results.²¹ No statistical significance can be given to the success of the case reported in this article, as the stability may merely be representative of the 32.0% referred to in Harris's study.²¹ However, this case report does serve as evidence that a 20-year success in the treatment of a GRD using an ADM is possible. Further study is necessary to determine the predictability of this result.

Douglas H. Mahn, DDS
Private Practice
Manassas, Virginia