A randomized clinical trial comparing enamel matrix derivative and membrane treatment of buccal class II furcation involvement in mandibular molars. Part II: secondary outcomes.

Background: This multicenter, randomized trial compared enamel matrix derivative (EMD) with barrier membranes for the treatment of Class II mandibular furcations with regard to secondary outcomes. The influence of furcation morphology on the effectiveness of either treatment was also evaluated. Methods: Forty-eight patients (age range 28 to 73 years; 22 females, 26 males) with buccal Class II furcation involvements in both contralateral lower first or second molars were included. After initial periodontal treatment, defects were randomized to either EMD or bioabsorbable guided tissue regeneration (GTR) barrier. Study design and the results for the primary parameter were previously described. Results of the following secondary outcome variables are reported here: changes of the hard tissue boundaries describing the anatomical situation of the furcation defect and changes in the following clinical parameters between baseline and 14 months: plaque, level of gingival margin, probing depth, bleeding on probing, attachment level, and bone sounding at five sites/tooth at the buccal side. Descriptive statistics were applied for changes in clinical parameters and measurements of hard tissue boundaries. The differences observed under treatment with EMD or membrane were analyzed by means of the Wilcoxon two-sample test. The difference between the effect of the EMD and membrane treatment was estimated by means of the Hodges-Lehmann estimator. Results: Overall, similar healing results were observed for both treatments. However, there was slightly more recession in the mid-furcation site following membrane treatment (P = 0.04). Additionally, different treatment effects could be detected for the distances from the stent or cemento-enamel junction (CEJ) to the buccal bone crest, mid-distal root (P-stent = 0.01; P-CEJ = 0.07) and for the distance from the stent or CEJ to the buccal bone crest, mid-mesial root (P-stent = 0.01; PCEJ = 0.01). There was no measurable bone resorption in EMD sites, whereas a slight resorption occurred with membrane treatment. Furcation morphology at the time of surgery was not associated with clinical outcome, irrespective of the treatment. Conclusion: With regard to secondary outcome parameters, enamel matrix derivative treatment led to a similar regenerative result as the membrane procedure.