Retrospective case series analysis of the factors determining immediate implant placement.

Implant placement at the time of extraction has become an acceptable treatment option. The formation of a restorative treatment plan frequently requires the removal of questionable and hopeless teeth. This retrospective case series analysis reports the reasons for tooth removal before immediate implant placement and provides a rationale for removing questionable and hopeless teeth. Root length is also analyzed as related to tooth loss. Between September 1986 and December 1998, 460 teeth were removed from 282 patients. Reasons for removal were advanced periodontal disease, endodontic complications, nonrestorable caries, roots fractures, short roots (< 14 mm in length), root resorption, and loosened posts. Implants were placed at the time of extraction. Tallies, frequency distributions, and percentages were used to determine individual and multiple reasons for extraction. For teeth with short roots, computerized measurements were made from periapical x-rays. Advanced periodontal disease and restored endodontically treated teeth with posts were the primary reasons for tooth extraction. Dental implants replaced 305 maxillary and 155 mandibular teeth.