The role of surgical flap design (minimally invasive flap vs. extended flap with papilla preservation) on the healing of intrabony defects treated with an enamel matrix derivative: a 12-month two-center randomized controlled clinical trial

Abstract

Objectives: Minimally invasive flap designs have been introduced to enhance blood clot stability and support wound healing. Limited data appear to suggest, that in intrabony defects, better clinical outcomes can be achieved by means of minimally invasive flap compared to more extended flaps. The aim of this study was to evaluate the healing of intrabony defects treated with either minimally invasive surgical flaps or with modified or simplified papilla preservation techniques in conjunction with the application of an enamel matrix derivative (EMD).

Materials and methods: Forty-seven subjects were randomly assigned to either test (N = 23) or control (N = 24) procedures. In the test group, the intrabony defects were accessed by means of either minimally invasive surgical technique (MIST) or modified minimally invasive surgical technique (M-MIST) according to the defect localization while the defects in the control group were treated with either the modified or simplified papilla preservation (MPP) or the simplified papilla preservation technique (SPP). EMD was used as regenerative material in all defects. The following clinical parameters were recorded at baseline and after 12 months: full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), probing depths (PD), clinical attachment level (CAL), and gingival recession (GR). Early healing index (EHI) score was assessed in both groups 1 week following the surgery. CAL gain was set as primary outcome.

Results: After 12 months follow-up, the CAL gain was 4.09 ± 1.68 mm in test group and 3.79 ± 1.67 mm in control group, while the PD reduction was 4.52 ± 1.34 mm and 4.04 ± 1.62 mm for test and control sites. In both groups, a minimal GR increase (0.35 ± 1.11 mm and 0.25 ± 1.03 mm) was noted. No residual PDs ≥ 6 mm were recorded in both groups. CAL gains of 4-5 mm were achieved in 30.4% and in 29.2% of test and control group, respectively. Moreover, CAL gains ≥ 6 mm were recorded in 21.7% of experimental sites and in 20.8% of control sites. No statistically significant differences in any of the evaluated parameters were found between the test and control procedures (P > 0.05). After 1 week post-surgery, a statistically significant difference (P < 0.05) between the groups was found in terms of EHI score.

Conclusions: Within the limits of this pilot RCT, the results have failed to show any differences in the measured parameters following treatment of intrabony defects with EMD, irrespective of the employed surgical technique.

Clinical relevance: In intrabony defects, the application of EMD in conjunction with either MIST/M-MIST or M-PPT/SPPT resulted in substantial clinical improvements.

Keywords: Enamel matrix derivative; Intrabony defects; Minimally invasive flaps; Periodontal disease; Randomized controlled trial; Surgical periodontal therapy; Wound healing.

Fig. 1

Surgical access to intrabony defect with modified minimally invasive surgical technique (M-MIST)

Fig. 2

EMD application after root conditioning using 24% EDTA gel

Fig. 3

Primary wound closure of interdental area

Fig. 4

Early wound healing at 1 week

Fig. 5

CONSORT flow diagram