Influence of Healing Abutment Height on Secondary Implant Stability Using Resonance Frequency Analysis: A Prospective Clinical Study

Background/Objectives: The aim of the present study is to evaluate the influence of the healing abutment height on secondary implant stability measured by resonance frequency analysis. In this prospective observational clinical study of 30 implants, the secondary stability of the implant was measured via resonance frequency analysis of the abutment during the osseointegration process. Methods: Two groups were compared: a <4 group (n = 15), with a space between the healing abutment and the antagonist of <4 mm, and a >= 4 group (n = 15), with a space of >= 4 mm. Results: Statistically significant differences (p < 0.05) in the implant stability values obtained at surgery (T0) and at the eighth week of osseointegration (T8) were observed between the two groups, with higher values for the <4 group. Pearson's correlation analysis revealed a trend towards a significant relationship with the mean force (-0.6546) and a linear inverse relationship, so that by decreasing the distance between the abutment and the contact with the antagonist, the secondary implant stability values increased. A comparison of the mesial and distal peri-implant marginal bone levels at T0 and T8 did not reveal statistically significant differences (p > 0.05). A greater healing abutment height, placing it closer to the antagonist, increases and accelerates secondary stability, as measured by resonance frequency analysis. Conclusions: The results of the study support the recommendation of using high healing abutments, placing the abutment close to the opposing occlusal plane, according to biomechanical criteria.