Bone Damage during Dental Implant Insertion: A Pilot Study Combining Strain Gauge and Histologic Analysis

Virgilia Klär,Matthias Karl,Tanja Grobecker-Karl

doi:10.3390/app12010291

Abstract

Besides alveolar bone quality, the drilling protocol applied in conjunction with the design of an implant are the major determinants of primary implant stability. Surgical trauma and bone compression resulting from implant insertion may constitute one cause for marginal bone resorption. Inserting two current bone-level implant designs (Astra; Straumann; n = 5) in bovine ribs, primary stability, strain development on the buccal bone plate and histologic signs of bone damage were recorded. Besides comparing the implant designs (Welch t-tests), all measurement parameters were checked for potential correlations (Pearson product moment correlation coefficients) with the level of significance set at α = 0.05. Considerable numbers of crack formation and plastic deformation of bone were observed after implant insertion. Straumann implants showed slightly greater values for insertion torque (p = 0.772), strain development (p = 0.893) and implant stability (p = 0.642). Significantly greater bone to implant contact (cortical p = 0.014; trabecular p = 0.016) was observed in Straumann implants, while Astra implants caused a significantly greater number of microcracks in cortical bone (p = 0.020). In Straumann implants, insertion torque correlated with bone to implant contact in the cortical area (p = 0.029) and the number of macrocracks in trabecular bone correlated with bone to implant contact (p = 0.029). In Astra implants, insertion torque and bone to implant contact in the trabecular area correlated (p = 0.007) as well as the number of macrocracks in trabecular bone and implant stability (p = 0.016). Additionally, in the area of cortical bone, the number of macrocracks correlated with bone to implant contact (p = 0.019). Implant placement results in bone damage of varying magnitude, which is governed by the drill protocol, implant macrodesign and bone quality.

Highlights

Publisher’s Note: MDPI stays neutralAlveolar bone consists of cortical and trabecular compartments in varying percent composition resulting in different bone qualities [1,2]
In Straumann implants, insertion torque correlated with bone to implant contact in the cortical area (p = 0.029), while in trabecular bone, the number of macrocracks correlated with bone to implant contact (p = 0.029)
While the insertion torque of Straumann implants correlated with bone to implant contact in the cortical area, for Astra implants, a correlation for insertion torque with bone to implant contact in trabecular bone was observed

Summary

Introduction

Publisher’s Note: MDPI stays neutralAlveolar bone consists of cortical and trabecular compartments in varying percent composition resulting in different bone qualities [1,2]. When dental implants are placed, primary stability reducing micromotion at the implant–bone interface in order to ensure osseointegration, has to be achieved. In this context, a clinical study showed that implants with low initial stability bear a higher risk of failure [3]. Implant manufacturers strive for maximizing primary stability by defining drill protocols depending on the hard to evaluate bone quality, and by designing implants often causing compression especially in the cortical layer of bone [2,4,5,6]. In an animal study comparing different drill protocols, a correlation between insertion torque and radiographic bone loss after 6 weeks of healing was found with implants achieving greater torque showing more marginal bone loss [7]. A with regard to jurisdictional claims in published maps and institutional affiliations

Methods

Discussion

Conclusion