Elsevier

Journal of Biomechanics

Volume 80, 26 October 2018, Pages 166-170
Journal of Biomechanics

Short communication
Effect of guided bone regeneration on bone quality surrounding dental implants

https://doi.org/10.1016/j.jbiomech.2018.08.011Get rights and content

Abstract

Bone quality as well as its quantity at the implant interface is responsible for determining stability of the implant system. The objective of this study is to examine the nanoindentation based elastic modulus (E) at different bone regions adjacent to titanium dental implants with guided bone regeneration (GBR) treated with DBM and BMP-2 during different post-implantation periods. Six adult male beagle dogs were used to create circumferential defects with buccal bone removal at each implantation site of mandibles. The implant systems were randomly assigned to only GBR (control), GBR with demineralized bone matrix (DBM), and GBR with DBM + recombinant human bone morphogenetic protein-2 (rhBMP-2) (BMP) groups. Three animals were sacrificed at each 4 and 8 weeks of post-implantation healing periods. Following buccolingual dissection, the E values were assessed at the defects (Defect), interfacial bone tissue adjacent to the implant (Interface), and pre-existing bone tissue away from the implant (Pre-existing). The E values of BMP group had significantly higher than control and DBM groups for interface and defect regions at 4 weeks of post-implantation period and for the defect region at 8 weeks (p < 0.043). DBM group had higher E values than control group only for the defect region at 4 weeks (p < 0.001). The current results indicate that treatment of rhBMP-2 with GBR accelerates bone tissue mineralization for longer healing period because the GBR likely facilitates a microenvironment to provide more metabolites with open space of the defect region surrounding the implant.

Introduction

Guided bone regeneration (GBR) has been used to promote bone growth into tissue defects adjacent to dental implants (Cho et al., 1998, Liu and Kerns, 2014). This technique installs a barrier membrane to cover the defect region, which prevents periodontal infection and fibrous tissue growth prior to new bone regeneration. On the other hand, osteoconductive and osteoinductive agents have been widely investigated to treat bone defects and augmentation next to implant. Demineralized bone matrix (DBM) is a decalcified bone allograft that contains organic components of bone including collagen, non-collagenous proteins, and bone growth factors (Huber et al., 2017, Urist, 1965). Also, bone morphogenetic protein-2 (BMP-2) has been observed as the most potent osteogenic agent for implant systems (Wei et al., 2012, Wikesjo et al., 2008). Thus, previous studies used BMP-2 in DBM as a carrier to amplify the osteoconductive and osteoinductive effects on osteogenesis at the bone-implant interface (Kim et al., 2016b, Sigurdsson et al., 2001). However, the effects of BMP-2 in DBM treatment with GBR on osteogenesis adjacent to a dental implant have not been fully investigated.

Active bone remodeling at the bone-implant interface produces less mineralized new bone tissues with weak mechanical properties (Brunski, 1999, Garetto et al., 1995, Kim et al., 2016b). The GBR adjacent to a metal implant is designed to trigger active bone modeling for fast filling new bone tissues in the empty defect space for an early post-implantation period. As a result, mineralization of the newly formed bone matrix at the GBR region may develop earlier than at the bone-implant interface. This different timing of mineralization may result in regional variation of the interfacial bone properties that play an important role in determining the local mechanical stability to resist microdamages including microcrack development at the tissue level of the bone-implant interface (Cha et al., 2015). Conventional testing tools can not directly measure the mechanical properties of bone at the narrow region of implant interface. Recently, many studies successfully showed that nanoindentation is a useful methodology to assess elastic property at the implant interface (Anchieta et al., 2018, Chang et al., 2003, Jimbo et al., 2013, Kim et al., 2016b, Vayron et al., 2012). Thus, the objective of this study is to examine the nanoindentation based elastic modulus (E) at different bone regions adjacent to titanium dental implants with GBR treated with DBM and BMP-2 during different post-implantation periods.

Section snippets

Materials and methods

The animal research protocol was approved by the Institutional Animal Care and Use Committee through Seoul National University, Korea (IACUC approval: SNU-090502-2). Following the approved IACUC protocol, all premolars and first molars in mandibles of 6 adult male beagle dogs (10–15 kg) were extracted. After a 3-month healing period, a 6.3 mm wide and 4 mm deep bone defect was created at each implant site with a trephine drill. The buccal bone wall of each defect was also removed to simulate a

Results

Nanoindentation elastic modulus (E) values were significantly different dependent on the region, post-implantation periods, and treatments (p < 0.001) (Table 1 and Fig. 3). The E values of the pre-existing region were significantly higher than those of the interface and defect regions independent of post-implantation periods and treatments (p < 0.001). The control and DBM groups had significantly higher E values at 8 weeks than those at 4 weeks of post-implantation period at the interface

Discussion

Active bone remodeling is triggered at the bone-implant interface to resorb the bone tissues damaged during rigorous implantation surgery and followed by osteoblastic new bone formation (Garetto et al., 1995, Kim et al., 2013, Kim et al., 2016b). It has been observed that the newly formed bone tissue is characterized by less mineral content and organized collagen than the old pre-existing bone tissues (Donnelly et al., 2010). Also, previous studies showed that elastic modulus (E) has a strong

Acknowledgements

This study was supported through the Delta Dental Foundation for Dental Master’s Thesis Award Program, the National Center For Advancing Translational Sciences (UL1TR001070), and Bio and Medical Technology Development Program of the National Research Foundation (NRF-2014M3A9E3064466) funded by the Ministry of Science, ICT & Future Planning. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center For Advancing

Conflict of interests

There are no conflicts of interest for any author.

References (29)

  • L.P. Garetto et al.

    Remodeling dynamics of bone supporting rigidly fixed titanium implants: a histomorphometric comparison in four species including humans

    Implant Dentistry

    (1995)
  • Seung-Hee Han

    Effect of Recombinant Human Bone Morphogenetic Protein-2 on Bone Regeneration around Zirconia Implants in Canine Dehiscence Defects

    (2012)
  • C.E. Hoffler et al.

    An application of nanoindentation technique to measure bone tissue Lamellae properties

    J. Biomech. Eng.

    (2005)
  • E. Huber et al.

    Demineralized bone matrix as a carrier for bone morphogenetic protein-2: burst release combined with long-term binding and osteoinductive activity evaluated in vitro and in vivo

    Tissue Eng. Part A

    (2017)
  • Cited by (25)

    • Selection of animal bone surrogate samples for orthopaedic screw testing based on human radius CT-derived bone morphology

      2022, Medical Engineering and Physics
      Citation Excerpt :

      As a general rule, the size, shape and number of implants (understood hereon and for the purpose of this study, as screw shaped objects) determines the animal model that should be used [21], meaning that the chosen implant must be tested in an animal bone with a size comparable to its human counterpart [22]. Because of this, animal bones and animal bone biopsies are selected mostly based on anatomical correspondence, that is for example, pedicle screws implanted in calf, sheep or pig spines [23–27] and dental implants placed in ovine, porcine and canine mandible [28–32]. However, is not uncommon to find ”odd” combinations such as dental screws implanted in bovine tibia [33] and porcine ribs [34,35] when certain morphological characteristics are desired, such as variable cortical thickness or specific bone volume fraction respectively, or dental screws implanted in sheep spine [6] with sample selection based purely on bone availability.

    • Synergistic effect of adding bioglass and carbon nanotubes on poly (lactic acid) porous membranes for guided bone regeneration

      2020, Materials Science and Engineering C
      Citation Excerpt :

      Guided bone regeneration (GBR) is a technique widely used in tissue regeneration using an occlusive membrane that sealing of a bone defects, and, in this way, physically prevents the entry of non-osteogenic cells into the defects [1,2]. This barrier allows the osteogenic cells to stimulate the formation of bone tissue at a rate higher than the growth of the connective tissue around them [3] and prevents periodontal infection when used in dental implants [4]. For this purpose, the material used should be biocompatible and biodegradable.

    • Spatio-temporal evolution of hydroxyapatite crystal thickness at the bone-implant interface

      2020, Acta Biomaterialia
      Citation Excerpt :

      Understanding the evolution of mineral crystal thicknesses at the interface can help comprehend the tissue mechanical properties. Nanoindentation campaigns measured lower elastics properties in newly formed bone around titanium implants compared to mature bone [35,53,54]. A relationship between mineral crystals thickness and elastic properties of bone tissue has been suggested for rabbit cortical bone [30], but only limited data has been gathered in the proximity of a metallic implant.

    • Multimodal characterization of the bone-implant interface using Raman spectroscopy and nanoindentation

      2020, Medical Engineering and Physics
      Citation Excerpt :

      In the future, more samples could be analyzed to further investigate the correlation between mechanical and compositional parameters and the effect of healing time. Another limitation lies in the sample preparation with the commonly used PMMA embedding resin [13,27,29,30], which can affect the results [62]. Nonetheless, embedding is necessary to enable slicing of the sample to expose the interface and minimize damage due to cutting in the presence of the titanium implant.

    • Bone regeneration into side openings and hollow inner channel of a dental implant

      2020, Journal of the Mechanical Behavior of Biomedical Materials
      Citation Excerpt :

      This result is consistent with the significantly lower nanoindentatin E values measured at the thread and ingrowth regions than the pre-existing region. We suggested that the active bone turnover at the bone-implant interface produces the newly forming less mature bone tissues resulting in the lower mechanical properties for the interfacial bone than the pre-existing bone away from the implant with different treatments and post-implantation healing periods (Kim et al., 2016b) and guided bone regeneration (Johnson et al., 2018) independent of buccal and lingual regions (Kim et al., 2016a). It was also observed that interfacial bone tissues in a porous implant had the less mature characteristics (Shah et al., 2016, 2019).

    View all citing articles on Scopus
    View full text