The effect of immediate implant placement on alveolar ridge preservation compared to spontaneous healing after tooth extraction: soft tissue findings from a randomized controlled clinical trial.

AIM to compare soft tissue dimensional changes and relative differences in soft and hard tissue volumes 4 months after single tooth extraction and 3 different treatment modalities: spontaneous healing (SH) and alveolar ridge preservation by means of a deproteneized bovine bone mineral and a collagen matrix, with (IMPL/DBBM/CM) or without (DBBM/CM) immediate implant placement. MATERIALS AND METHODS STL files from study casts obtained at baseline and after 4 months were matched to calculate buccal soft tissues linear and volumetric changes. DICOM file from CBCTs were superimposed to STL files allowing the evaluation of soft tissue thickness at baseline and 4 month. RESULTS mean horizontal reduction accounted for 1.46 ± 0,20 (SH), 0.85 ± 0.38 (DBBM-CM) and 0.84 ± 0,30 IMPL/DBBM-CM, with no statistically differences. Soft tissue thickness had a significant mean increase of 0.95 for SH group, compared to a non-significant mean decrease for DBBM-CM (0.20) and IMPL/DBBM-CM group (0.07). CONCLUSION a preservation technique with DBBM-CM, with or without immediate implant placement, didn't reduce the horizontal linear and volumetric changes at the buccal soft tissue profile significantly at 4 months after tooth extraction when compared to spontaneous healing. This is due to a significant increase in soft tissue thickness in spontaneously healing sites.