Real-Time Imaging of Gap Progress during and after Composite Polymerization

The aims of this study were to observe the behavior of composite and formation of gaps during and immediately after light polymerization using swept source optical coherence tomography (OCT) and to compare the interfacial integrity of adhesives in cavities through 3-dimensional (3D) image analysis. Forty tapered cylindrical cavities (4-mm diameter, 2-mm depth) were prepared in bovine incisors and restored using Bond Force (BF), Scotchbond Universal Adhesive (SBU), OptiBond XTR (XTR), or Clearfil SE Bond 2 (SE2), followed by Estelite Flow Quick flowable composite. Real-time imaging was performed at the center of restoration by the OCT system (laser center wavelength: 1,330 nm; frequency: 30 KHz) during and up to 10 min after light curing. The 3D scanning was performed 0, 1, 3, 5, and 10 min after light curing. The percentages of sealed enamel and dentin interface area (E%, D%) were calculated using Amira software. In real-time videos, the initial gaps appeared as a bright scattered area mainly on dentin floor and rapidly progressed along the cavity floor. The timing, rate, and extent of gap formation were different among the specimens. From 3D visualization, gap progress could be seen on both enamel and dentin even after irradiation; furthermore, typical toroidal gap patterns appeared at the dentin floor of BF and SBU. XTR and SE2 showed nearly perfect sealing performance on the dentin floor up to the 10 min that images were recorded. From quantitative analysis, SE2 and XTR showed significantly higher E% and D% than other groups. SBU showed the smallest E% and BF showed a significantly smaller D% than other groups (P < 0.05). In conclusion, real-time observation of composite placement and 3D quantification of interfacial gaps were implemented within the experimental limitations. Interfacial gap formation during polymerization of the composite depended on the adhesive system used. The formed gaps continued to propagate after composite light curing finished.

[1]  Chih-Han Chang,et al.  Shrinkage behaviors of dental composite restorations-The experimental-numerical hybrid analysis. , 2016, Dental materials : official publication of the Academy of Dental Materials.

[2]  B. Van Meerbeek,et al.  Mini-interfacial fracture toughness as a new validated enamel-bonding effectiveness test. , 2016, Journal of the mechanical behavior of biomedical materials.

[3]  J. Ferracane,et al.  Polymerization stress--is it clinically meaningful? , 2016, Dental materials : official publication of the Academy of Dental Materials.

[4]  A. Sadr,et al.  Microgaps and Demineralization Progress around Composite Restorations , 2015, Journal of dental research.

[5]  Alireza Sadr,et al.  Application of Optical Coherence Tomography (OCT) for Diagnosis of Caries, Cracks, and Defects of Restorations , 2015, Current Oral Health Reports.

[6]  F. Schwendicke,et al.  Influence of using different bonding systems and composites on the margin integrity and the mechanical properties of selectively excavated teeth in vitro. , 2015, Journal of dentistry.

[7]  J. Ferracane,et al.  Composite polymerization stress as a function of specimen configuration assessed by crack analysis and finite element analysis. , 2013, Dental materials : official publication of the Academy of Dental Materials.

[8]  A. Versluis,et al.  Polymerization shrinkage stresses in a premolar restored with different composite resins and different incremental techniques. , 2013, The journal of adhesive dentistry.

[9]  Amir Nazari,et al.  Nondestructive assessment of current one-step self-etch dental adhesives using optical coherence tomography , 2013, Journal of biomedical optics.

[10]  S. Heintze.  Clinical relevance of tests on bond strength, microleakage and marginal adaptation. , 2013, Dental materials : official publication of the Academy of Dental Materials.

[11]  Y. Sumi,et al.  Concurrent evaluation of composite internal adaptation and bond strength in a class-I cavity. , 2013, Journal of dentistry.

[12]  B. Van Meerbeek,et al.  Bonding of low-shrinking composites in high C-factor cavities. , 2012, Journal of dentistry.

[13]  Alireza Sadr,et al.  Evaluation of resin composite polymerization by three dimensional micro-CT imaging and nanoindentation. , 2011, Dental materials : official publication of the Academy of Dental Materials.

[14]  Alireza Sadr,et al.  Non-destructive 3D imaging of composite restorations using optical coherence tomography: marginal adaptation of self-etch adhesives. , 2011, Journal of dentistry.

[15]  R. Frankenberger,et al.  Long-term degradation of enamel and dentin bonds: 6-year results in vitro vs. in vivo. , 2010, Dental materials : official publication of the Academy of Dental Materials.

[16]  Alireza Sadr,et al.  Validation of swept-source optical coherence tomography (SS-OCT) for the diagnosis of occlusal caries. , 2010, Journal of dentistry.

[17]  R. Belli,et al.  In vitro wear gap formation of self-adhesive resin cements: a CLSM evaluation. , 2009, Journal of dentistry.

[18]  Li Shi,et al.  A two-stage shape optimization process for cavity preparation. , 2008, Dental materials : official publication of the Academy of Dental Materials.

[19]  K. Tsubota,et al.  Influence of irradiation time on volumetric shrinkage and flexural properties of flowable resins. , 2007, Dental materials journal.

[20]  Alexandre A L Barcellos,et al.  ANALYSIS OF GAP FORMATION AT TOOTH-COMPOSITE RESIN INTERFACE: EFFECT OF C-FACTOR AND LIGHT-CURING PROTOCOL , 2007, Journal of applied oral science : revista FOB.

[21]  V. Rousson,et al.  Recommendations for conducting controlled clinical studies of dental restorative materials , 2007, Clinical Oral Investigations.

[22]  F. Tay,et al.  Water sorption/solubility of dental adhesive resins. , 2006, Dental materials : official publication of the Academy of Dental Materials.

[23]  J. M. Singer,et al.  Influence of cavity dimensions and their derivatives (volume and 'C' factor) on shrinkage stress development and microleakage of composite restorations. , 2006, Dental materials : official publication of the Academy of Dental Materials.

[24]  P. Lambrechts,et al.  Extension of a one-step self-etch adhesive into a multi-step adhesive. , 2006, Dental materials : official publication of the Academy of Dental Materials.

[25]  J. Ferracane,et al.  Measuring the residual stress in dental composites using a ring slitting method. , 2005, Dental materials : official publication of the Academy of Dental Materials.

[26]  Jack L Ferracane,et al.  Developing a more complete understanding of stresses produced in dental composites during polymerization. , 2005, Dental materials : official publication of the Academy of Dental Materials.

[27]  A. Versluis,et al.  Polymerization shrinkage: effects of boundary conditions and filling technique of resin composite restorations. , 2004, Journal of dentistry.

[28]  Antheunis Versluis,et al.  Residual shrinkage stress distributions in molars after composite restoration. , 2004, Dental materials : official publication of the Academy of Dental Materials.

[29]  R. Frankenberger,et al.  Influence of c-factor and layering technique on microtensile bond strength to dentin. , 2004, Dental materials : official publication of the Academy of Dental Materials.

[30]  R. Sakaguchi,et al.  Contraction force rate of polymer composites is linearly correlated with irradiance. , 2004, Dental materials : official publication of the Academy of Dental Materials.

[31]  Franklin R Tay,et al.  Have dentin adhesives become too hydrophilic? , 2003, Journal.

[32]  J. Perdigão,et al.  Morphological study of resin-dentin bonding with TEM and in-lens FESEM. , 2003, American journal of dentistry.

[33]  F. Tay,et al.  Single-step adhesives are permeable membranes. , 2002, Journal of dentistry.

[34]  M. Burrow,et al.  Effects of Dentin Depth and Cavity Configuration on Bond Strength , 1999, Journal of dental research.

[35]  B Van Meerbeek,et al.  Polymerization shrinkage and elasticity of flowable composites and filled adhesives. , 1999, Dental materials : official publication of the Academy of Dental Materials.

[36]  D C Watts,et al.  Determination of polymerization shrinkage kinetics in visible-light-cured materials: methods development. , 1991, Dental materials : official publication of the Academy of Dental Materials.

[37]  F. Barbakow,et al.  Quality and durability of marginal adaptation in bonded composite restorations. , 1991, Dental materials : official publication of the Academy of Dental Materials.

[38]  A. J. Goldberg,et al.  Clinical Evaluation Methods for Posterior Composite Restorations , 1984, Journal of dental research.