Über den Autor
Nölken R, Quaas S
Clinical indication for implants with a sloped shoulder contour – a pilot study
In a retrospective analysis of CBCT scans Ahlskog et al. identified radiographic indication for implants with a sloped shoulder contour, meaning that level differences of the buccal and lingual/palatal aspect of evaluated possible implant sites were between 1.3 mm to 5 mm, in 47,9% of 383 pre-implant sites. Since prosthodontic and surgical considerations influence the decision for an implant with a sloped marginal contour clinical indications for the OsseoSpeed™ Profile EV are still unclear 1,2. Therefore this pilot study focuses on the clinical indications for implants with a sloped marginal shoulder contour.
Material and methods
In 20 prepared implant sites apicocoronal level differences of the buccal and lingual/palatal aspect of the crestal alveolar bone in relation to the implant axis were evaluated. Measuring clinical level differences between the buccal and lingual/palatal aspect of the alveolar bone was performed immediately after preparation of the cavity for a 4.2 mm diameter implant through inserting the last straight drill and evaluating present level differences with a dental mm probe, or alternatively a caliper (Prof. Krekeler/Dr. Beschnidt, Helmut Zepf Medizintechnik, Figs. 5a to 5b). Level differences between 1-5 mm were considered as clinical indication for an OsseoSpeed™ Profile EV.
The mean apicocoronal height difference between the buccal and lingual/palatal aspect of the prepared implant sites was 2.0 ± 2.1 mm (Range: 0 to 8 mm). In 70% (14/20) of the implant sites level differences between 15 mm in respect to the planned implant axis were evaluated. In 40% (8/20) of these sites an OsseoSpeed™ Profile EV was inserted. In 40% (8/20) of the situations with level differences between 1 to 5 mm present an implant with a straight contour of the shoulder was placed subcrestally and/or the remaining defect was augmented to achieve a corresponding length of the clinical crown to adjacent teeth, in two of these eight cases implant length was below 8 mm. In 10% (2/20) of the implant sites apicocoronal level differences were greater than 5 mm, still an OsseoSpeed™ Profile EV was inserted in combination with simultaneous augmentation of bone.
- Ahlskog L, Nölken R, Wagner W. Radiographic indication for implants with a sloped shoulder contour: I. Extraction sites. unpublished 2017.
- Ahlskog L, Nölken R, Wagner W. Radiographic indication for implants with a sloped shoulder contour: II. Healed sites. unpublished 2017.
- Accuracy of clinical measuring in respect to the implant axis is limited, 1 mm steps are recommendable.
- Prosthodontic and surgical considerations influence clinical indication for implants with a sloped marginal contour 1,2.
- Since 1 mm subcrestal placement can be feasable prosthodontic considerations can lead to clinical indication in straight situations.
- Clinical indication for implants with a sloped marginal shoulder contour is more common than anticipated.
- The sloping of crestal alveolar bone can vary in direction, reversed sloped situations are possible.
- The reduction in complexity of simultaneous augmentation relates to the height variance of the sloped marginal shoulder contour.
- Narrow diameter and short implants with a sloped marginal shoulder contour are desirable.
- Further clinical investigations including more patients are needed to evaluate the clinical indication for implants with a sloped shoulder contour.