Background: Animal and human researches have shown that immediate implant placement into extraction sockets failed to prevent socket dimensional changes following tooth extraction. It has been suggested that a minimal width of 1-2 mm of buccal bone is necessary to maintain a stable vertical dimension of the alveolar crest.
Aim: To determine the dimensions of the bony wall at extraction sites in the esthetic zone (anterior teeth and premolars in the maxilla) and relate it to immediate implant placement.
Methods: As part of an ongoing prospective randomized-controlled multicenter clinical study on immediate implant placement, the width of the buccal and palatal bony walls was recorded at 93 extraction sites.
Results: The mean width of the buccal and palatal bony walls was 1 and 1.2 mm, respectively (P<0.05). For the anterior sites (canine to canine), the mean width of the buccal bony wall was 0.8 mm. For the posterior (premolar) sites, it was 1.1 mm (P<0.05). In the anterior sites, 87% of the buccal bony walls had a width < or = 1 mm and 3% of the walls were 2 mm wide. In the posterior sites, the corresponding values were 59% and 9%, respectively.
Conclusions: If the criterion of a minimal buccal bone width of 2 mm to maintain a stable buccal bony wall is valid, only a limited number of sites in the anterior maxilla display such a clinical situation. The data suggested that in the majority of extraction sites in the anterior maxilla, thin (< or = 1 mm) buccal walls were present. This, in turn, means that in most clinical situations encountered, augmentation procedures are needed to achieve adequate bony contours around the implant.