Volume gain and stability of peri-implant tissue following bone and soft tissue augmentation: 1-year results from a prospective cohort study.

OBJECTIVES: the aim of the present study was to evaluate the dimensional changes of peri-implant tissues obtained by implant placement, bone and soft tissue augmentation, prosthetic reconstruction and 1 year of function using a new, non-invasive method for volumetric measurements.

MATERIALS AND METHODS: in 16 patients, the missing central or lateral maxillary incisor was reconstructed with an implant-supported single crown. Impressions were taken before (t1), after implant placement with guided bone regeneration using DBBM and a PTFE membrane (t2), after soft tissue augmentation (t3), immediately after crown placement (t4) and 1 year later (t5). The cast models were optically scanned and digitally superimposed allowing qualitative and quantitative analysis of alterations of the labial peri-implant tissue contour. In addition, the crown length and papilla height were measured at crown placement (t4) and after 1 year (t5).

RESULTS: fifteen patients were available for recall after 1 year. During therapy, a mean gain in distance in the labial direction of 1.27 ± 0.67 mm was observed after the surgical procedures. One year after crown insertion, a mean loss of 0.04 ± 0.31 mm in the labial direction was recorded. During the same period, the crown length increased by a mean of 0.22 ± 0.57 mm and the papilla height by 0.07 ± 0.61 mm. The degree and pattern of tissue change following crown insertion were highly variable between individuals, irrespective of the amount and quality of previously augmented tissues.

CONCLUSIONS: the clinical procedures were effective in augmenting peri-implant tissue volume that remained stable to a high degree within 1 year after crown insertion. Large inter-individual variations regarding the tissue alterations were observed.