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Updated: Apr 30, 2026

An Improved Mechanical Testing Method to Assess Bone-implant Anchorage
Published on: February 10, 2014
Comparative histological and histomorphometrical evaluation of marginal bone resorption around external hexagon and
Daniel Sartorelli Marques de Castro1, Maria Angelica Rehder de Araujo, Cesar Augusto Magalhães Benfatti
1*Research Fellow, Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil. †Private Practice, São Paulo, Brazil. ‡Professor, Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil. §Professor of Oral Pathology, Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy. ‖Research Fellow, Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy. ¶Researcher, Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy.
Purpose:
Aim of this study was to evaluate the histological and histomorphometrical differences at the marginal bone level with the use of 2 different implant-abutment assembly designs (the traditional External Hexagon and the Morse Cone tapered connections).
Methods:
Nine Morse Cone and 9 External Hexagon implants were inserted in 6 mongrel dogs. The Morse Cone implants were installed 2 mm below the crestal bone level, whereas the External Hexagon flush. The implants were retrieved after 2 months. Mean distance between the original level of coronal bone to the top of the implant and the mean distance between the top of the implant and the first bone-to-implant contact (fBIC) were recorded.
Results:
No significant differences were found when the mean distance between the original level of coronal bone to the top of the implant was evaluated; however, there were statistically significant differences in the mean distances between the top of the implants and fBIC, suggesting a smaller amount of bone loss or remodeling in the Morse Cone compared to the External Hexagon group.
Conclusion:
Subcrestal placement had a positive impact on crestal bone remodeling in Morse Cone implants.

