Platform Switching vs Conventional Platform: What Does the Bone Loss Data Actually Tell Us?
Platform switching has been one of the more discussed concepts in implant dentistry over the past two decades. The premise is intuitive: by using an abutment with a smaller diameter than the implant platform, you create a horizontal mismatch that shifts the implant-abutment interface away from the crestal bone, theoretically reducing bone loss. Many clinicians have adopted platform switching on that basis, and a significant body of literature supports it.
A 2023 comparative study published in the Journal of Health Sciences by Prof. Muhamed Ajanović and colleagues at the University of Sarajevo Faculty of Dentistry examined this assumption directly — and the findings are worth understanding carefully.
Why Crestal Bone Loss Matters
Crestal bone height around an implant is one of the primary radiographic criteria for assessing implant treatment success. The accepted benchmark is that bone loss of 1.5 mm or less in the first year of functional loading falls within normal physiological limits and does not jeopardize implant survival. After the first year, annual bone loss below 0.2 mm is considered a success criterion for long-term implant health.
When bone loss exceeds these thresholds — or when it continues progressively — the long-term prognosis of the implant becomes increasingly uncertain. Understanding which implant designs and surgical approaches minimize crestal bone loss is therefore a directly clinically relevant question.
The Study — Design and Methods
The study analyzed 443 dental implants across 115 patients treated at the University of Sarajevo Faculty of Dentistry. Two implant systems were compared:
161 Bredent blueSKY implants — conventional platform, internal Torx tube-in-tube connection
282 Ritter spiral implants — platform switching, external hexagon with internal anti-rotation
Patients ranged from 19 to 63 years of age (63 male, 52 female). All underwent delayed prosthetic loading and two-stage implant surgery. Crestal bone loss was measured on panoramic radiographs and CBCT cross-sections before implantation and after one year of functional loading, on both the mesial and distal aspects of each implant.
The measurement methodology was consistent: crestal bone loss was calculated from the coronal portion of the abutment to the visible margin of the alveolar bone on each side. Patients with pathological changes, peri-implantitis, or who were outside the 18–65 age range were excluded.
The Results — What the Numbers Show
Both implant systems performed well within the accepted bone loss thresholds. Crestal bone loss after one year was below the critical 1.5 mm value for all groups, which the authors appropriately characterize as a successful outcome for both systems.
The detailed figures:
Location Bredent blueSKY (mean ± SD) Ritter Spiral (mean ± SD) Maxilla 0.55 ± 0.39 mm 0.88 ± 0.04 mm Mandible 0.58 ± 0.32 mm 0.75 ± 0.07 mm
When measured by implant surface:
Side Bredent blueSKY Ritter Spiral p-value Mesial resorption 0.61 mm 0.75 mm < 0.001 Distal resorption 0.60 mm 0.93 mm < 0.001
The differences were statistically significant on both the mesial and distal aspects (p < 0.001 for both). The platform-switching system (Ritter spiral) showed greater crestal bone loss than the conventional platform system (Bredent blueSKY) at all measurement points.
What This Means — A Counterintuitive Finding
The finding is counterintuitive relative to much of the published literature, which has generally reported lower crestal bone loss around platform-switched implants. The authors acknowledge this directly and discuss several possible explanations.
Implant-Abutment Connection Design
While both systems use an internal implant-abutment connection, the specific geometries differ substantially. The Bredent blueSKY uses an internal Torx tube-in-tube design with six large force transfer surfaces, while the Ritter spiral uses an external hexagon that is parallel to an internal hexagon. These structural differences affect how forces are distributed at the implant-abutment interface and may influence crestal bone behavior independently of the platform configuration.
Platform Mismatch Magnitude
Existing research suggests that the degree of platform mismatch matters significantly. Studies have found that mismatches greater than 0.45 mm produce better outcomes than smaller mismatches. The magnitude of the platform switch in the Ritter spiral system used in this study is not directly comparable to the systems that produced favorable outcomes in pro-platform-switching literature.
Implant Diameter Differences
Implant diameters also differed between the two groups: Bredent implants were 3.5 mm and 4.0 mm, while Ritter implants were 3.75 mm, 4.2 mm, and 5 mm. Implant diameter affects the biomechanical stress distribution at the crestal bone level, and this variable cannot be fully controlled for in a comparative study of this kind.
The Multi-Factor Reality
The authors make a point that is clinically important and often underappreciated: crestal bone loss around implants is almost certainly the result of multiple interacting factors — implant design, surface treatment, degree of roughness, surgical technique, loading protocol, patient factors, and the implant-abutment connection geometry. Attributing bone loss outcomes to a single variable like platform switching versus conventional platform oversimplifies a complex biological reality.
Clinical Takeaways
Several points from this study are worth integrating into clinical thinking:
Both systems succeeded within clinical norms. It is essential to note that crestal bone loss in both groups was well below the 1.5 mm threshold after one year. Neither system failed to meet the established criteria for implant success. The difference between the groups is real and statistically significant, but both outcomes are clinically acceptable.
Platform switching is not a universal bone preservation strategy. The automatic assumption that platform switching reduces crestal bone loss is not consistently supported across all implant systems. The connection geometry, the magnitude of the mismatch, the implant diameter, and the surface characteristics all interact to produce the final bone level outcome. Selecting a system based on the platform concept alone — without considering these other variables — is an oversimplification.
Implant system selection should be evidence-based and system-specific. The research supporting platform switching was largely conducted on specific implant systems at specific mismatch values. Extrapolating those findings to all platform-switched systems is not justified by the available evidence.
Radiographic monitoring remains essential. Regardless of implant system choice, standardized radiographic follow-up at one year and annually thereafter is necessary to detect early bone loss before it becomes clinically significant. The values established in this study provide useful reference points for what constitutes normal bone remodeling.
Study Limitations
This was a retrospective comparative study rather than a randomized controlled trial. The two groups differed in implant diameter, connection geometry, and implant number, making direct attribution of the observed differences to the platform concept alone difficult. Different imaging techniques were also used for the two groups — panoramic radiographs for Bredent implants and CBCT cross-sections for Ritter implants — which introduces a potential measurement variability.
Future prospective randomized studies controlling for implant diameter, connection design, and imaging methodology would provide more definitive data on the isolated effect of platform switching on crestal bone levels.
In Summary
This 2023 study from the University of Sarajevo provides real-world clinical data on crestal bone loss around 443 implants across two systems over one year. The key finding — that platform-switched implants showed greater crestal bone loss than conventionally configured implants in this patient population — challenges a widely held clinical assumption and underscores the importance of evaluating implant systems based on their specific design characteristics rather than on broad categorical features like platform configuration.
Both systems produced bone loss within clinically acceptable limits, and both can be considered successful by established criteria. The practical message is nuance: platform switching is a concept with theoretical merit and supporting evidence in specific contexts, but it is not a reliable universal predictor of superior bone preservation across all implant systems.
This article is based on: Ajanović M, Kamber A, Tosum Pošković S, Dervišević A, Tucak K. Comparison of values of crestal bone loss around dental implants: A comparative study. Journal of Health Sciences. 2023;13(3):193-195. https://doi.org/10.17532/jhsci.2023.2419
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