Some effects of enamel matrix proteins on wound healing in the dento-gingival region

Objective: The aim of the present study was to evaluate by clinical means the effect of enamel matrix proteins on the healing of a soft tissue wound produced by periodontal pocket instrumentation. Material and methods: The study was performed as an intra-individual, longitudinal trial of 3 weeks duration with a double-masked, split-mouth, placebo-controlled and randomized design. The patient material was comprised of 28 subjects with moderately advanced, chronic periodontitis. Each patient presented with 3 sites in each of 2 jaw quadrants with a probing pocket depth (PPD) of greater than or equal to5 mm and bleeding following pocket probing (BoP). Baseline examination, including assessments of plaque, gingival inflammation, PPD, BoP and root dentin sensitivity, was carried out one week after oral hygiene instruction and careful self-performed plaque control. All experimental sites were scaled and root planed, and the soft tissue wall of the pocket was curetted to remove the pocket epithelium and adjacent granulation tissue. The site was carefully irrigated with saline. When the bleeding from the pocket had ceased, a 24% EDTA gel was applied in the site and retained for 2 min. This was followed by careful irrigation with saline. Left and right jaw quadrants were then randomized to subgingival application of enamel matrix derivative (Emdogain(R)) or vehicle-control. All sites were re-examined after 1, 2 and 3 weeks. In addition, a visual analogue scale (VAS) was used to score the degree of post-treatment discomfort. The primary endpoints of treatment success were defined as (i) pocket closure (PPD less than or equal to4 mm), (ii) no bleeding following pocket probing, (iii) no sign of gingival inflammation (GI score =0) and (iv) low degree of post-treatment discomfort (VAS less than or equal to20). Statistical analyzes of intra-individual differences between the test and control treatments were performed by the use of Wilcoxon signed rank test. For comparison of the proportions of sites reaching the defined endpoints of treatment success, a site-based analysis was performed using 2X2 tables and the Fisher exact test. Results: The endpoint GI score =0 was reached at 16% of the sites subjected to application of Emdogain(R) at 1 week and at 2% of the control sites (p= 0.001). At 2 weeks, the corresponding figures were 25% versus 12% (p =0.028). Absence of BoP was at 1 week 57% for the Emdogain(R) treated sites compared to 35% for the control sites (p=0.003). At 2 weeks, this endpoint was reached in 73% and 59% of the test and control sites, respectively (p=0.051). In terms of the endpoint defined for probing pocket depth, PPD less than or equal to4 mm, no differences between test and control sites were found. At 1 week, the proportion of patients reporting a VAS score less than or equal to20 was significantly higher for the Emdogain(R) treated quadrants than for controls (p=0.002). Conclusion: The results indicated that Emdogain(R) topically applied in instrumented pockets enhance the early healing of periodontal soft tissue wounds.