Radiographic findings demonstrated similar values after 7 years as the baseline regarding defect depth height in 6/12 treated implants. Three implants, one in the PTG group and two in the OFD group, had progression of radiographic defect depth height, measured at the deepest site, compared to baseline.

Assessing the results after 12 months, five of the implants in the PTG group and five of the implants in the OFD group had progression of radiographic defect depth height.

There was an aggravation in mean radiographic osseous defect level of 1.9 mm ± 2 and 1.3 mm ± 1.4 in the PTG group and OFD group, respectively.

Three implants demonstrated improved radiographic defect depth height, measured at the deepest site, at 7 years compared to baseline. Two implants represented the PTG group and one implant the OFD group.

The PTG graft particles were seemingly scattered, as judged by radiographs (Fig. 2). Loss of grafting material was extensive in two cases, and most grafting material was still present in the osseous defect in two cases. At test sites where the implant had been lost, some remaining PTG particles were seen in the surrounding tissue.

The aim of the study was to evaluate the long-term clinical and radiographic results from a study on peri-implant osseous defect reconstruction [12].

Minimal differences were observed when comparing the two groups at baseline, 12-month and the 7-year examinations, but the power to detect a true difference at the 7-year examination was small due to the low number of patients finally re-examined.

Most of the implants had a deeper radiographic defect depth after 7 years compared to the 12-month examination, and minimal differences were seen when comparing with baseline measurements. It is therefore important to consider the original osseous defect depth around treated implants when aiming to diagnose stable peri-implant conditions [16]. Moreover, three of the implants in the test group had lost all bony attachment and had been explanted. However based on the evaluation presented here, it was not possible to clarify if differences in patient-related factors such as the original defect depth or treatment modality were causative for this outcome.