Clinical and radiographic outcomes of the modified minimally invasive surgical technique with and without regenerative materials: a randomized-controlled trial in intra-bony defects.

AIMS This three-arm study compared the clinical and radiographic efficacy of the modified minimally invasive surgical technique (M-MIST) alone and combined with enamel matrix derivative (EMD) or EMD plus bone mineral derived xenograph (BMDX), in the treatment of isolated, inter-dental intra-bony defects. MATERIALS AND METHODS Forty-five deep isolated intra-bony defects in 45 patients were included, accessed with the M-MIST and randomly assigned to three balanced experimental groups. The M-MIST consisted of a small buccal flap without elevation of the defect-associated papilla. After removal of the granulation tissue by sharp dissection and root instrumentation the regenerative material was applied, when indicated, before obtaining primary closure with a single internal modified mattress suture. Surgery was performed with the aid of an operating microscope and microsurgical instruments. Outcomes were evaluated as pocket depth reduction, attachment level gain, radiographic bone fill and patient-related outcomes. RESULTS Primary wound closure was maintained in all treated sites with the exception of one M-MIST EMD+BMDX site. No patient reported intra-operative or post-operative pain. Within group differences between baseline and 1 year were statistically significant in the three groups in terms of probing pocket depth reduction, clinical attachment level (CAL) gain and bone fill (p<0.0001). Comparisons among the thre groups showed no statistically significant difference in any of the measured clinical outcomes. In particular, CAL gains of 4.1±1.4mm were observed in the M-MIST control group, 4.1±1.2mm in the EMD group and 3.7±1.3mm in the EMD+BMDX one. The percentage radiographic bone fill of the intra-bony component was 77±19% in the M-MIST control group, 71±18% in the EMD group and 78±27% in the EMD+BMDX group. CONCLUSIONS M-MIST with or without regenerative materials resulted in significant clinical and radiographic improvements. While this initial study did not have sufficient power to detect inter-group CAL differences <0.96mm, the observed outcomes were remarkably similar and warrant further investigations.