Fogorvosi szemle, 2007 (100. évfolyam, 1-6. szám)

2007-10-01 / 5. szám

226

FOGORVOSI SZEMLE ■ 100. évf. 5. sz. 2007.

trabony defects by open flap surgery with and without EMD. In 23 patients with at least 2 intrabony defects each a total of 53 defects were treated with open flap surgery + EMD and 31 were treated only with open flap surgery alone. After a healing phase of 12 months the defects were again opened and the defect fill measured. The results showed that the treatment with open flap surgery + EMD resulted in a 3 times larger defect fill than the treatment with flap surgery alone (74% defect fill after flap surgery + EMD vs. 23% defect fill after flap surgery alone) [93], In a further prospective, controlled clinical study a total of 40 patients were treated by surgical therapy with either EMD or GTR with a non-bioabsorbable or with 2 bioabsorbable barriers and compared to the open flap surgery (control) [94], All 4 regenerative procedures were equally effective regarding probing depth (PD) reduction and CAL gain and, significantly better than the control treatment. A prospective, randomized, multi-centre clinical study reported the treatment of intrabony defects with the papilla preservation technique with and without auxiliary application of EMD [95]. A total of 83 test and 83 control defects were treated. After 1 year the results showed significantly higher CAL gain in the test group than in the control group [95], On the other hand, one very recent randomized, double-masked, placebo-controlled clinical trial has failed to show significant differences in clinical and radiographic parameters following treatment of intrabony defects with open flap debridement and application of EMD or placebo [96], However, most data from controlled clinical studies indicate that the additional application of EMD in the context of surgical therapy of deep intrabony periodontal defects may lead to significantly higher gains of clinical attachment and defect fill compared to open flap debridement [92-95, 97-102], Surgical treatment with EMD was also demonstrated to significantly improve supracrestal soft-tissue density compared to open flap debridement alone [103, 104], However, neither the postoperative administration of amoxicillin and metronidazole, nor of a selective cyclo-oxygenase-2 inhibitor seemed to additionally enhance the clinical results [105, 106]. Furthermore, two studies have suggested that the clinical outcomes in intrabony defects treated with EMD do not depend on the use of EDTA root conditioning [107, 108]. Comparative studies reported similar results after treatment of intrabony defects with EMD or GTR, whereby the type of the GTR barrier (non bioabsorbable or bioabsorbable) did not play a role [94, 98-101, 109, 110]. The clinical results are comparable to those after GTR therapy. A recent prospective multi-centre, randomized, controlled clinical trial compared the clinical outcomes of EMD versus GTR with a bioabsorbable membrane [110]. Seventy five patients with advanced chronic periodontitis were recruited in 7 centres in 3 countries. The surgical procedures included access for root instrumentation using the simplified papilla preservation flap and either the application of EMD or placement of a resorbable GTR membrane. The results of the trial have failed to demonstrate superiority of one treatment over the other. It was interesting to note that all cases treated with GTR presented at least one surgical complication, mostly membrane exposure, while only 6% of EMD treated sites displayed complications.

The data also indicate that the clinical results after treatment of intrabony defects with EMD can be maintained over a longer time period (up to 5 years) [111- 114].

Combination therapies in intrabony defects Experimental and clinical studies have indicated that the extent of the regeneration is determined by the available space under the mucoperiostal flap [115, 116]. A collapse of the mucoperiostal flap may limit the area needed for the regeneration process and may thus affect the result of the therapy. In order to avoid these disadvantages, combination therapies between EMD and GTR and/or EMD and bone substitutes were tested. Observations from animal-histological and humanhistological studies have demonstrated periodontal regeneration after treatment of intrabony defects with some of these combinations. In a prospective, controlled, clinical study the treatment of intrabony defects was evaluated following treatment with EMD, GTR, a combination of EMD + GTR, and open flap surgery [99]. The results have shown that all 3 regenerative procedures resulted in a significantly higher improvement of the clinical parameters compared to the conventional flap surgery; whereby the combination of EMD + GTR led to no additional improvement. Comparable results were also reported by others [117, 118]. A prospective, controlled split-mouth study has evaluated in 11 patients with a total of 12 pairs of intrabony defects the clinical response of EMD with or without a combination of a tetracycline-coated expanded polytetrafluoroethylene barrier membrane (e-PTFE) [118]. The results were evaluated at 6 and at 12 months following therapy. After 12 months, the mean CAL gain measured 1.28 ± 2.04 mm in the EMD group and 1.65 ± 1.29 mm in the EMD + GTR group, respectively. Except for more postoperative discomfort at the membrane treated sites, the results failed to reveal any significant differences between the 2 groups.

Several studies have evaluated the effect of a combination of EMD and various types of bone grafts/bone substitutes in the treatment of intrabony defects. Data from human histologic studies indicate that a combination of EMD and a natural bone mineral or bioactive glass may indeed result in formation of root cementum, periodontal ligament and mineralization around the graft particles [119, 120]. On the other hand, the application of a natural bone mineral alone resulted also in periodontal regeneration [119]. However, when the defects were filled with a bioactive glass alone, the healing was characterized by formation of a long junc-