Microsurgical access flap and enamel matrix derivative for the treatment of periodontal intrabony defects:: a controlled clinical study

Objectives: Application of the guided tissue regeneration (GTR) principle and utilization of enamel matrix derivative (EMD) have both been shown to result in periodontal regeneration. While clinical investigations have demonstrated that the use of a microsurgical concept in combination with the GTR technique positively affects the percentage of primary closure and the amount of tissue preservation, no such information is available for EMD-treated periodontal defects. It was the aim of the present investigation to assess the clinical effect of the microsurgical access flap and EMD treatment with an emphasis on the evaluation of early wound healing. Material and Methods: Eleven patients displaying at least one pair of intrabony periodontal defects with an intrabony component of greater than or equal to3 mm participated in the study. At baseline and at 6 and 12 months after surgery, the following clinical parameters were assessed by a blinded examiner: oral hygiene status (API), gingival inflammation (BOP), probing pocket depth (PPD), clinical attachment level (CAL) and gingival recession (GR). Defects were randomly assigned to test or control treatment, which both consisted of a microsurgical access flap procedure designed for maximum tissue preservation. The exposed root surfaces of the test sites were conditioned with a 24% EDTA gel followed by EMD (Emdogain((R)) ) application. Primary flap closure was achieved by a 2-layered suturing technique. Postoperative healing was evaluated by a newly introduced early wound-healing index (EHI) at 1 and 2 weeks after surgery. Results: Both test and control treatment resulted in a statistically significant mean CAL gain of 2.8 and 2.0 mm at 6 months, and 3.6 and 1.7 mm at 12 months, respectively (p <0.05). Differences in CAL gain between the two treatment modalities were statistically significant at both time points (p <0.05). Additional GR values after 12 months averaged 0.3 and 0.4 mm for test and control sites, respectively, and did not reach statistical significance (p greater than or equal to0.05). Two weeks after surgery, primary closure was maintained in 89% of the test sites and in 96% of the control sites. Conclusion: Both treatment modalities using the microsurgical flap procedure resulted in a high percentage of primary flap closure and maximum tissue preservation. In terms of PPD reduction and CAL gain, the combination with EMD application appeared to be superior to the microsurgical access flap alone.