Immediate placement and loading of implants with laser-microgrooved collar in combination with an anorganic porcine bone mineral matrix in the esthetic zone. Twelve-month results of a prospective multicenter cohort study.

Abstract

Many techniques have been proposed to address post-extraction ridge resorption, which often represents a concern, especially in the esthetic region. The purpose of the present, prospective, multicenter, single cohort study was to investigate, up to 1 year of function, the effectiveness of a protocol for alveolar ridge preservation involving implants with laser-microgrooved surface immediately placed in fresh extraction sockets. Twenty eight patients candidate to tooth extraction in the esthetic zone (site 15-25 and 35-45) were treated by immediate placement of a single laser-microgrooved implants with the adjunct of a highly porous anorganic porcine bone mineral matrix and a collagen wound dressing. Peri-implant marginal bone level (MBL) was evaluated at time of loading, 3 and 12 months after loading. Gingival index, plaque index, probing depth, and bleeding on probing were measured at 3, 6, and 12 months after loading. Dimensional changes at implant sites were digitally evaluated using the best-fit superimposition of pre-and post-socket preservation models. Implant aesthetic score (IAS) as well as patients' post-operative quality of life were also evaluated at 12 months. Comparisons between data relative to thick and thin gingival phenotypes were made using Student's t-test or Mann-Whitney test, as appropriate. The significance level was set at p = 0.05. No patient dropped out, and 28 implants were evaluated at 12 months post-loading. The overall MBL was found to be 0.92 ± 1.11 mm. Volumetric analysis of superimposed models showed an alveolar bone tissue displacement at the buccal aspect of -0.57 ± 0.52 mm in thin phenotypes and -0.46 ± 0.31 mm in thick phenotypes (p = 0.58, unpaired Student's t-test). No signs of soft tissue recession or esthetically unpleasant buccal gingiva were reported. The clinical protocol herein employed showed benefits in maintaining marginal bone levels and soft tissue contour around post-extraction implants in the esthetic zone.