Platform switch – to be or not to be?

Andrija Petar BošnjakSchool of Dental Medicine, Zagreb, Croatia

Andrej MenigaPrivate practice, Zagreb, Croatia

Ann Wennerberg, Victoria FröjdSchool of Dentistry, Göteborg, Sweden

Background

Bone resorption to the first thread during initial loading

Biologic width around implants (Berglundh & Lindhe 1996)

No resorption when an abutment with a narrower diamater is connected to the implant (Gardner 2005) – so called platform-switching

Objective

Evaluation of the difference in histological findings between a platform-switching implant-to-abutment interface using a tight seal and a flat-to-flat interface

Differences in ISQ values during 3 months for implants with transmucosal healing (one-stage procedure)

Material and methods

26 consecutive patients treated with 43 Ospol study implants

4.0 diameter, implant length of 10, 12 and 15 mm supporting single crowns or fixed partial dentures

36 implants (83.7%) – single tooth replacements in lateral parts of mandible (58.8%) and maxilla (41.2%)

Material and methods

Paired implants

One with a healing abutment – creating

flat-to-flat interface

One with a standard abutment – creating platform switch interface

Material and methods

2×2 mm biopsy of soft tissue was acquired 3 months after implant placement for histological evaluation (at the time of crown/fixed partial denture fixation)

Immersed in sodium-cacodylate solution and subsequently analyzed

Material and methods

Radiographic assessment of marginal bone levelAt the time of implant placementAt 3 months recall (time of crown fixation)

All patients were recalled monthly during osseointegration process

ISQ measurements at the time of surgery and 3 months postoperatively

Results

Cross-sections of fixated samples

Inflammatory cell inflitrateThickness of the epitheliumThickness of the connective tissue

Platform switch

No substantial number of inflammatory cells

Epithelial thickness

Well-defined “rete pegs”

Connective tissue layer

Flat-to-flat

No substantial inflammatory cell infiltrate

Epithelial thickness

Connective tissue layer

ISQ measurements

Platform-switch(± SD)

Flat-to-flat(± SD)

p

At implant placement

72.5 ± 6.3 71.8 ± 5.9 NS

At 1 month 77.3 ± 4.2 77.1 ± 3.8 NS

At 3 months 81.8 ± 5.5 80 ± 4.7 NS

Conclusion

Histologic analysis is in the early stage, but there is no significant inflammatory cell infiltrate

Platform-switch seems to be as reliable for one-stage procedures as flat-to-flat interface

ISQ measurements confirm that the stability was maintained during initial three months of healing

Further developments

Further developments

Further developments

Acknowledgments

Ospol, Malmö, SwedenGöran Urde & Hans Berglund @ Ospol, Malmö, SwedenPetra Hammarström Johansson @ Dept

Biomaterials/Handicap Research, Göteborg, SwedenMartina Vlah, Gordana Sporis & Lana Vodopija @

Meniga & Bosnjak LLC, Zagreb, CroatiaKresimir Sankovic, School of Pharmacy, Zagreb,

CroatiaDrazen Jovicevic, Dental Laboratory, Zagreb, Croatia