Behaviour of soft tissues healing around single bone-level-implants placed immediately after tooth extraction A 1 year prospective cohort study

Aim The aim of this study was to verify if the three-dimensional implant position in fresh alveolar socket may influence the maintenance of stable gingival margins around single premolar restorations with immediate implant placement. Methods After 16 weeks of healing, implants were loaded with single crowns. Documentation consisted in peri-apical radiographs taken: before treatment; at the time of implant placement; at the time of prosthetic rehabilitation and 12 months after the start of prosthetic function. Parameters assessed were: the presence/absence of inter-proximal papilla; the inter-implant–tooth distance (ITD); the distance from the base of the crown contact-point to the inter-dental bone crest (CPB); and the buccal-gingival tissue modifications. ITD, CPB values and the modification of buccal-gingival tissue were determined using an image processing software. Results Twenty-one healthy patients with thick gingival biotype, with a total of 21 maxillary premolars scheduled for extractions were enrolled. Following extraction, implants were immediately positioned. A 100% of implant survival rate was observed after 12 months of function. The presence of the mesial papilla was significantly correlated with the mean mesial CPB value (P = 0.0519 by means of two-tailed Mann–Whitney U-test). No significant correlation was found between the mesial papilla presence and the mean mesial ITD score (P = 0.7722 by means of two-tailed Mann–Whitney U-test). Furthermore, the presence of the distal papilla was not significantly correlated with the mean distal ITD and CPB values: scores of 0.7195 and 0.8225 were calculated respectively. Conclusion In the premolar area, the relationship between the presence of a complete inter-proximal papilla and ITD parameter was not significant (P > 0.05). The relationship between the presence of a complete inter-proximal papilla and CPB parameter still remain unclear. Nevertheless, a more large sample size is required to confirm this trend. Moreover, it was observed that the buccal-gingival tissue withdrew in the range 0–1 mm after 1 year of prosthetic function.