Riaan Mulder

Volumetric change of flowable composite resins due to polymerization as measured with an electronic mercury dilatometer

Abstract Background: To determine the total volumetric change and the relative speed of shrinkage of bulk fill flowable composites during polymerization. Materials and methods: A specially

In vitro analysis of the marginal adaptation and discrepancy of stainless steel crowns

Abstract Aim: The purpose of the study was to assess the marginal adaptation and discrepancy of SSC’s. Differences in adaptation and discrepancy between the four surfaces (mesial, lingual, distal, and buccal) were evaluated. Methods: The placement of stainless steel crowns were completed on a phantom head in accordance with the clinical technique. The ideal tooth preparation was made and this ‘master tooth’ duplicated to achieve a sample size of 15. The stainless steel crowns were placed, trimmed, and cemented as per the clinical technique. The cemented stainless crowns were analyzed under 100× stereomicroscope magnification. The marginal adaptation and discrepancy of each specimen was measured every 2 µm. Results: All the specimens showed marginal adaptation and discrepancy. The lingual margin had a significantly better adaptation (p < .0001) over the other surfaces. The buccal surface was the only surface that had an appropriate supra-CEJ level with a significance of p < .0001. Conclusion: The marginal discrepancies occur during the trimming procedure and assessment of the gingival approximation of the SSC margin. The inspection of stainless steel crown adaptation and discrepancy is an essential clinical step.

Towards bioactive dental restorative materials with chitosan and nanodiamonds: evaluation and application

Traditional dentistry has now evolved to a stage where, under optimal conditions, success rates of up to over 90% have been reported for some procedures (for example, for dental implants) after a period of 10 years [1]. The development of new materials with enhanced properties, careful attention to factors that influence the technique sensitivity of some procedures, and a generally greater awareness of oral health issues among the population have all helped to contribute to these improvements in treatment outcomes [2]. Bioactive materials have evolved over the past three decades from relatively specialized, highly biocompatible, but low-strength dental materials into product compositions for expanded clinical use in restorative dentistry [3].