Impact of defect configuration on the clinical outcome following surgical regenerative therapy of peri‐implantitis

OBJECTIVES: The present study aimed at investigating the impact of defect configuration on the clinical outcome of surgical regenerative therapy of peri-implantitis lesions using a natural bone mineral in combination with a collagen membrane (NBM+CM). MATERIALS AND METHODS: Twenty-seven patients (n=27 defects) exhibited three different types of peri-implantitis lesions including either Class Ib (buccal dehiscence+semicircumferential), Class Ic (buccal dehiscence+circumferential), or Class Ie (circumferential) intra-bony defects (n=9 defects per group). All defects were treated with access flap surgery and the application of NBM+CM. RESULTS: At 6 and 12 months, Class Ie defects tended to reveal higher changes in the mean probing depth (PD) and clinical attachment level (CAL) values when compared with Class Ib and Class Ic groups. However, significant differences were only observed at 6 months (PD: 2.9 +/- 0.3 versus 1.4 +/- 0.5 versus 1.3 +/- 0.7 mm; CAL: 2.5 +/- 0.5 versus 0.9 +/- 0.8 versus 0.9 +/- 0.7 mm). Site-level analysis has pointed to lowest PD and CAL changes at the midbuccal aspect of Class Ib and Class Ic groups. CONCLUSION: Defect configuration may have an impact on the clinical outcome following surgical regenerative therapy of peri-implantitis lesions. While Class Ie defects seem to be promising in conjunction with NBM+CM, Class Ib and Class Ic may be considered as unfavourable.