Thermal response of a dental tissue induced by femtosecond laser pulses

Abstract

This paper reports a theoretical and experimental study for thermal transport in a thin slice of human tooth induced by a 120 fs, 800 nm pulse laser at a repetition rate of 1 kHz. The surface reflectivity of enamel and the convection heat transfer coefficient were determined using an inverse heat transfer analysis. Instead of a fully three-dimensional modeling, two simplified two-dimensional (2D) planar and axisymmetric heat conduction models were proposed to simulate the temperature fields. The temperature responses obtained from the 2D planar and axisymmetric model agree well with the experimental measurements. On the other hand, the one-dimensional (1D) result significantly differs from the 2D axisymmetric one, suggesting that care should be taken when a 1D thermal model is considered for estimating temperature response.

Peptide-Based Scaffolds Support Human Cortical Progenitor Graft Integration to Reduce Atrophy and Promote Functional Repair in a Model of Stroke

“…In addition to the structural support provided by the scaffold nanofibrils, which likely contributed to improved graft survival and integration, were the benefits of tissue-specific scaffold presentation of the functional laminin epitope, IKVAV. Previous studies have reported IKVAV, the motif from the a1 chain of the laminin-1 peptide sequence, promotes neuronal cell attachment, migration, differentiation, and neurite outgrowth (Cheng et al, 2013;Silva et al, 2004;Tashiro et al, 1989), including that of hESC-derived neurons (Ma et al, 2008). In support, here, we report enhanced neuronal specification of hESC-derived neural grafts in the presence of the IKVAV scaffold, as well as augmented deep (TBR1) and superficial (BRN2) cortical layer specification of NPCs, necessary for the replacement of neurons lost to the primary insult.…”

“…Use of biomaterials is increasingly being recognized as a valuable adjunct approach for cell-based therapies and may impart physical and trophic support to both host and grafted cells (Jendelová et al, 2016). A variety of natural and synthetic polymers, such as collagen, chitosan, and poly(lactic acid), as well as decellularized scaffolds, have been employed to support neural grafts in the ischemic brain (Bible et al, 2009(Bible et al, , 2012Cheng et al, 2013;Elias and Spector, 2012;Jin et al, 2010;Liang et al, 2013;Park et al, 2002;Yu et al, 2010;Zhong et al, 2010). While these materials have shown variable anatomical and functional benefits, most optimal for regenerative medicine will be the employment of readily injectable nanomaterials that self-assemble from biologically active molecules.…”

Biophysical Consequences of EVEN-PLUS Syndrome Mutations for the Function of Mortalin

“…The k cat values determined for each of the wild type NBD constructs in this study (Table 3) are lower than those measured by Sevier and colleagues, 48 however the k cat and K M values we found are consistent with the range of previously reported k cat (0.83 -0.031 min −1 ) and K M (270 -0.11 μM) values for either isolated NBDs or full-length Hsp70s. 49,[55][56][57][58][59][60][61] The diseaseassociated mutations severely impaired catalytic activity of mortalin-NBD (Figure 7). R126W mortalin-NBD exhibited a ~65% decrease in the catalytic activity and 30% weaker K M of 230 ± 50 μM compared to the wild type mortalin-NBD.…”

Physiochemical characteristics: A robust tool to overcome teeth heterogeneity on predicting laser ablation profile

“…Though there are numerous experimental studies attempt to predict the laser ablation profile are quite far and few. 15,18,26 Most of the studies [27][28][29][30][31][32] are computational model which requires complete knowledge of thermophysical properties and extensive computational resources. 5 Even computational models are tractable only for homogeneous materials like metal, the difficulty in incorporating heterogeneity of the teeth make these models unreliable.…”