title: Zirconia enriched dental adhesive: a solution for OCT contrast enhancement. Demonstrative study by synchrotron radiation microtomography.
abstract: OBJECTIVE
  The major aim of this study was to prove the capability of the optical coherence tomography (OCT) method in visualizing the integrity of the adhesive fillings and of the interfaces between the adhesive, tooth structures and composite resin. As zirconium dioxide was added to the composition of the adhesive layer in order to strengthen the backscattered light in the OCT investigation, for a better visualization of the interfaces, the determination of a proper zirconia concentration was another aim of our study.
  
  
  METHODS
  Several class II cavities were prepared in human premolars and were filled with dental adhesive containing different zirconia concentrations and light-curing composite resin. Both OCT and synchrotron radiation microtomography (micro-CT) were used to analyse the morphology of the tooth-adhesive-composite interfaces and to investigate the adhesive layer.
  
  
  RESULTS
  The pore distribution, both at the interfaces level and in the resin, and the analysis of the adhesive layer integrity were obtained. A good agreement between OCT and micro-CT analyses was observed in terms of detecting discontinuities in the adhesive layer. Furthermore, micro-CT showed that zirconia percentages in the adhesive higher than 20 vol.% lead to conglomerates formation, which can negatively influence mechanical properties. Meanwhile, OCT confirmed a factor of 3 for the contrast enhancement when 20% of zirconia was included in the adhesive composition.
  
  
  CONCLUSIONS
  The present study proved the capability of the OCT method in visualizing the morphology and integrity of zirconia doped tooth adhesive fillings, to be used for a further in vivo tool development.
authors: Universitatea de Medicina si Farmacie "Victor Babes", Facultatea de Medicina Dentara, Timisoara, Romania.
authors: Mihai
authors: M
authors: Rominu
authors: Università Politecnica delle Marche - Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche, Sezione di Biochimica, Biologia e Fisica, Ancona, Italy. Electronic address: a.manescu@alisf1.univpm.it.
authors: Adrian
authors: A
authors: Manescu
authors: Universitatea de Medicina si Farmacie "Victor Babes", Facultatea de Medicina Dentara, Timisoara, Romania.
authors: Cosmin
authors: C
authors: Sinescu
authors: Universitatea de Medicina si Farmacie "Victor Babes", Facultatea de Medicina Dentara, Timisoara, Romania.
authors: Meda Lavinia
authors: ML
authors: Negrutiu
authors: Universitatea de Medicina si Farmacie "Victor Babes", Facultatea de Medicina Dentara, Timisoara, Romania.
authors: Florin
authors: F
authors: Topala
authors: Universitatea de Medicina si Farmacie "Victor Babes", Facultatea de Medicina Dentara, Timisoara, Romania.
authors: Roxana Otilia
authors: RO
authors: Rominu
authors: University of Kent, Applied Optics Group, School of Physical Sciences, CT2 7NH Canterbury, UK.
authors: Adrian
authors: A
authors: Bradu
authors: University of Kent, Applied Optics Group, School of Physical Sciences, CT2 7NH Canterbury, UK.
authors: David A
authors: DA
authors: Jackson
authors: Università Politecnica delle Marche - Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche, Sezione di Biochimica, Biologia e Fisica, Ancona, Italy.
authors: Alessandra
authors: A
authors: Giuliani
authors: University of Kent, Applied Optics Group, School of Physical Sciences, CT2 7NH Canterbury, UK.
authors: Adrian Gh
authors: AG
authors: Podoleanu
mesh_terms: D001641:Bicuspid; D003188:Composite Resins / Q000737:chemistry*; D003731:Dental Caries / Q000628:therapy*; D003738:Dental Cements / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D066298:In Vitro Techniques; D055115:Light-Curing of Dental Adhesives; D013499:Surface Properties; D017356:Synchrotrons; D041623:Tomography, Optical Coherence; D055114:X-Ray Microtomography; D015040:Zirconium / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D015040:Zirconium; C028541:zirconium oxide
keywords: Contrast enhancement; Medical imaging; Optical coherence tomography; Synchrotron radiation; Tooth adhesive; X-ray microtomography