This defect shape will favor the stabilization of a graft material to be used. Narrow 2 wall defects are still good indications for reconstructive osseous surgery, but are not as ideal as 3 wall defects. Interproximal craters, which are common 2 wall interproximal defects, may be an indication for reconstructive osseous surgery if the defect is narrow. Wide craters such as the one seen on the slide respond better to osseous resection than periodontal regeneration. One wall defects such as the one present on the mesial aspect of this maxillary first molar are poor indications for periodontal regeneration since it is difficult to stabilize the graft material to be used in its proper place.
Circumferential defects are the ones that involve more than one surface of a tooth.
Once again, if they are narrow they may be a good indication for periodontal regeneration whereas wide ones are not.