Treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration

BACKGROUND

Utilisation of enamel matrix proteins (EMD) and application of the guided tissue regeneration principle (GTR) are treatment modalities which both have been shown to result in periodontal regeneration. However, it is yet unknown whether the combination of EMD and GTR may additionally favor the regeneration process.

AIM

The aim of the present controlled study was to evaluate clinically the treatment effect of EMD, GTR, combination of EMD and GTR, and flap surgery (control) on intrabony defects.

MATERIAL AND METHODS

56 patients each of whom displaying one intrabony defect of a depth of at least 6 mm were randomly treated with one of the treatment modalities. Prior to surgery and at one year after, the following parameters were evaluated by a blinded examiner: Plaque index (PlI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), gingival recession (GR) and clinical attachment level (CAL). No statistical significant differences between the four groups were observed at baseline for any of the investigated parameters.

RESULTS

At 1 year after therapy, the sites treated with EMD demonstrated a mean PPD reduction of 4.1 +/- 1.7 mm and a mean CAL gain of 3.4 +/- 1.5 mm (p<0.001). The sites treated with GTR showed a mean PPD reduction of 4.2 +/- 1.9 mm and a mean CAL gain of 3.1 +/- 1.5 mm (p<0.001). The sites treated with the combined treatment showed a mean PPD reduction of 4.3 +/- 1.4 mm and a mean CAL gain of 3.4 +/- 1.1 mm (p<0.001). In the control group, the mean PPD reduction was 3.7 +/- 1.4 mm (p<0.001) and the mean CAL gain measured 1.7 +/- 1.5 mm (p<0.01). All 4 treatments led to statistically significant PPD reduction and CAL gain. All three regenerative treatments led to higher CAL gain than the control treatment (p<0.05). No statistical significant differences in PPD reduction and CAL gain were observed between the three regenerative treatments.

CONCLUSION

It may be concluded that (a) all 3 regenerative treatment modalities may lead to higher CAL gain than the control one, and (b) the combined treatment does not seem to improve the outcome of the regenerative procedure.

Clinical and histologic evaluation of human intrabony defects treated with an enamel matrix protein derivative (Emdogain)

An enamel matrix protein derivative (Emdogain) has been recently shown to promote periodontal regeneration in experimentally created recession-type defects. However, only limited histologic data from human material are available concerning the healing of intrabony periodontal defects following treatment with Emdogain. The aim of the present study was therefore to present the clinical and histologic results following the application of Emdogain in intrabony defects. Two patients with marginal periodontitis and deep intrabony defects adjacent to teeth scheduled for extraction were treated with Emdogain. The postoperative healing phase was uneventful in both cases. At 6 months following treatment, newly formed cementum with inserting collagen fibers was found in both specimens. In one case, the new attachment formation was also accompanied by bone neoformation. The results of this human histologic study indicate that Emdogain possesses the potential to stimulate new connective tissue attachment formation in human intrabony defects.

GTR with bioresorbable membranes in the treatment of intrabony defects: a clinical and histologic study

The aim of the present study was to evaluate clinically and histologically the treatment of intrabony periodontal defects with a bioresorbable membrane barrier. Fifty-two intrabony periodontal defects were treated according to the principles of guided tissue regeneration (GTR) with a bioresorbable membrane. Results were evaluated by assessing probing pocket depth, recession of the gingival margin, and clinical attachment level at baseline and at 1 and 2 years after therapy. Bone level changes were evaluated radiographically. The postoperative phase was uneventful in all cases. There was a mean probing pocket depth reduction from 8.4 to 3.6 mm, a mean increase of gingival margin recession from 1.5 to 3.0 mm, and a mean clinical attachment level change from 9.9 to 6.5 mm. Mean attachment gain was 3.4 mm. Two teeth scheduled for extraction were also treated with the same bioresorbable membrane. The histologic analysis 6 months after treatment revealed the formation of new connective tissue attachment and new alveolar bone in both cases. Based on the histologic findings it can be concluded that the clinical improvements following GTR with this type of bioresorbable membrane may represent, at least in part, true periodontal regeneration.

Treatment of intrabony periodontal defects with an enamel matrix protein derivative (Emdogain): a report of 32 cases

Enamel matrix proteins, including Emdogain, have been proposed as a new modality for regenerative periodontal treatment. However, limited information is available concerning the clinical applicability and therapeutic results with Emdogain. The aim of the present study was therefore to evaluate the clinical outcome following the application of Emdogain in the treatment of intrabony periodontal defects. Twenty-eight patients with marginal periodontitis (thirty-two 2- and 3-walled intrabony defects) were included in this study. The following parameters were evaluated prior to treatment and 8 months after treatment: probing pocket depth, recession of the gingival margin, and clinical attachment level. The postoperative healing phase was uneventful in all cases. There were no complications such as allergic reactions, abscess formation, or infections throughout the entire study period. The mean probing pocket depth was reduced from 8.7 +/- 1.5 mm at baseline to 4.3 +/- 1.6 mm after 8 months (P < 0.001), the mean gingival recession increased from 1.8 +/- 1.2 mm to 3.3 +/- 0.9 mm, and the mean clinical attachment level changed from 10.6 +/- 1.9 mm to 7.6 +/- 1.8 mm (P < 0.001). New hard tissue formation was radiographically observed in 26 of the 32 defects. The present results suggest that the treatment of intrabony periodontal defects with Emdogain may lead to significant improvements of all of the investigated clinical parameters. However, controlled histologic and clinical trials are needed to compare this treatment modality with other conventional and regenerative periodontal surgical methods.

The effect of a deproteinized bovine bone mineral on bone regeneration around titanium dental implants

The aim of the present experiment was to test the effect of a deproteinized bovine bone mineral (Bio-Oss) on guided bone regeneration (GBR) in dehiscence defects around implants. The first 2 molars and all premolars were extracted on both sides of the mandibles of 3 monkeys (Macaca fascicularis). Three months later, 2 titanium plasma-coated cylindrical implants were placed in all quadrants of each monkey. During the surgical procedure, standardized dehiscence defects were produced buccally and lingually, measuring 2.5 mm in width and 3 mm in height. Four different experimental situations were created: 2 sites in each monkey were covered with an ePTFE membrane (M), 2 were filled with the graft material (DBBM), 2 were filled with the graft material and also covered with a membrane (M + DBBM), and 2 control sites were neither grafted nor covered (C). The flaps were sutured to allow for primary healing. Linear measurements of bone height and width were calculated on histological specimens obtained 6 months following surgery. In addition, values for bone density and for surface fraction of graft to new bone contact were measured. Vertical bone growth along the implant surface of 100% (SD 0%) for M + DBBM, 91% (SD 9%) for M, 52% (SD 24%) for DBBM, and 42% (SD 35%) for C was measured. The width of the regenerated bone 1.5 mm above the bottom of the original defect, i.e. at the 50% mark of the vertical extension of the defect, in relation to the width at the bottom of the defect amounted to 97% (SD 2%) for M + DBBM, 85% (SD 9%) for M, 42% (SD 41%) for DBBM, and 23% (SD 31%) for C. Assessment of bone density within the confinement of the regenerated bone resulted in an increase of 30% (SD 11%) for M + DBBM, 45% (SD 20%) for M, 33% (SD 20%) for DBBM, and 22% (SD 23%) for C. The values for graft to new bone contact within this compartment amounted to 80% (SD 15%) for M + DBBM and 89% (SD 14%) for DBBM. In conclusion, Bio-Oss exhibited osteoconductive properties and hence can be recommended for GBR procedures in dehiscence defects with respect to vertical and horizontal growth of bone.