Saturday, June 15, 2013

Investigation of Biodentine as dentine replacement material

Available online 15 May 2013

Abstract

Objective

Biodentine was compared to glass ionomer and resin modified cements in an “open sandwich” restoration.

Methods

Fuji IX, Vitrebond and Biodentine were characterised using various techniques. The effect of etching with 35% phosphoric acid was investigated by assessment of surface topography, Fourier transform infrared (FT-IR) spectroscopy, surface micro-hardness and micro-leakage using tagged carboxylated-modified fluorescent microspheres and tracing the presence of these particles with a confocal microscope.

Results

Acid etching resulted in erosion of the material surface with exposure of the glass particles in the glass ionomer-based materials. Biodentine exhibited a reduction in the chlorine peak and the calcium–silicon ratio. There was no difference in the micro-hardness in etched and un-etched materials. The FT-IR plots did not show any chemical changes caused by etching for all the materials investigated. Both Vitrebond and Fuji IX exhibited no leakage at the dentine to material interface while Biodentine exhibited leakage both when it was etched and also when the surface was left unprepared. The sandwich technique was effective and prevented micro-leakage with glass ionomer-based materials but micro-leakage occurred with Biodentine.

Conclusions

Biodentine demonstrated both structural and chemical changes when etched with 37% phosphoric acid. Biodentine exhibited a lower calcium to silicon ratio and a reduction in the chloride peak height when etched. When used as a dentine replacement material in the sandwich technique overlayed with composite, significant leakage occurred at the dentine to material interface. On the other hand materials based on glass ionomer cement were etched successfully and no chemical and physical changes or micro-leakage were detected when the materials were used as bases under composite restorations. The micro-hardness of all the materials was unaffected by etching.

1 comment:

Howard Strassler said...

Marty- I saw your blog posted on June 15, 2013 on the investigation of biodentine. I was surprised to see this abstract posted. I had seen the abstract because of my interest in vital pulp therapy with the calcium silicate materials. The reason for my surprise is that you posted an abstract without having read the article to review the whether or not the protocol for the research had clinical relevance. I am a member of a number of advisory boards and editorial boards for journals. Also, as a disclosure I am on an advisory board for Septodont. My interest in the topic piqued my interest because I knew of the abstract. When I searched for the article- it was not available. I was able to finally get an "in press" copy. Maybe you saw the "in press" copy from the publisher or author. The full article reported on using Biodentine for an open sandwich restoration. Biodentine is not recommended for open sandwich restorations. An open sandwich restoration, usually a Class II or Class V for at risk gingival margins due to caries, is usually restored with glass ionomer (GIC) and composite. The rationale for glass ionomer is the benefits of fluoride release at the gingival margin restored with the GIC and the rechargeability of the Fl in the GIC. None of the calcium silicate and MTA-portland cement materials like Biodentine claim fluoride release hence not recommended for open sandwich. Also the protocol was not evaluating an open sandwich restoration but the restoration of a Class I cavity preparation. Open sandwich restorations have been shown in clinical studies to be problematic due to the adaptation of the gingival margin with a GIC to a matrix band. I had questions about the methodology of the study to draw the conclusions that were drawn. Also, the bonding of composite to a liner/dentin replacement material has never been demonstrated to be relevant. It sounds good that the materials adhere to each other, but the physical properties to support the composite are much more important. I refer you to two collaborative research projects that Dental Advisor and I presented at the IADR meeting in San Diego in 2012 - Yapp R, Strassler H, Bracho-Troconis C, Richard G, Powers J. Compressive deflection of composite layered on Biodentine and two bases. J Dent Res (AADR Abstracts). 2012; 91:abstract no. 1021 and Yapp R, Strassler H, Bracho Troconis C, Richard G, Powers J. Compressive deflection of Biodentine and two glass ionomer bases. J Dent Res (AADR Abstracts). 2012; 91:abstract no. 1020. Also there are other research studies that contradict some of the conclusions from the research data. John Burgess's group at the University of Alabama reported on zero microleakage of Biodentine, Bentley K, Janyavula S, Cakir D, Beck P, Ramp L, Burgess J. Mechanical and physical properties of vital pulp therapy materials. J Dent Res (AADR Abstracts). 2012; 91: abstract no. 258. Also, reference 7 in the full article states that Biodentine performs as well as the resin glass ionomer cement in open-sandwich restorations- Koubi S, Elmerini H, Koubi G, et al. Quantitative evaluation by glucose diffusion of microleakage in aged calcium silicate-based open sandwich restorations. Inter J Dent, 2012; 2012:105863. I have to wonder if the laboratory assistant was well versed in the placement of the materials tested. From my experience in the research lab- this can be problematic. We all need to respect a manufacturers recommendations, researchers need to test materials appropriately, and clinical relevance from reading through research protocols will benefit all clinicians in helping them make good sound clinical decisions for their patients. Howard Strassler, DMD