The correlation between remaining dentin thickness and fracture resistance in prepared teeth is of interest to dentists. A sample of 60 human teeth (mandibular premolars) was extracted and examined using cone beam computed tomography to assess residual dentin thickness before and after instrumentation. The gathered samples have been divided into three distinct categories, each with 20 samples. Hand files were used in Group 1, Protaper Next was used in Group 2, and a V taper was used in Group 3. They were examined for remaining dentin thickness after preparation with 3D CS Software and fracture resistance utilizing a Universal Testing Machine (UTM). Therefore, the objective of this research is to compare the amount of dentin removed by V Taper and Pro Taper Next to hand files using CBCT at the apical and coronal middle levels. Following that, these values will be correlated with fracture resistance values obtained from the Universal Testing Machine.

Introduction: Clinical evidence of platelet-rich fibrin (PRF) benefits on bone repair is still emerging, prompting researchers to experiment with different PRF formulations as osteoconductive scaffolds. Aims: This study compared the osteoconductive effects of injectable PRF (i-PRF) and leukocyte-rich PRF (L-PRF) on the differentiation of dental pulp stem cells (DPSCs) into osteoblasts. Materials and Methods: Blood samples were collected from the volunteers to prepare L-PRF and i-PRF conditioned media (CM) by centrifugation. DPSCs were isolated from impacted third molars and cultured. Proliferation of DPSCs in response to L-PRF and i-PRF was assessed by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Osteoinductive potential was evaluated through alkaline phosphatase (ALP) activity, alizarin red S (ARS) staining, growth factor levels (vascular endothelial growth factor [VEGF], transforming growth factor [TGF-beta]), and cytokine expression (interleukin 6 [IL-6], IL-8) after 7 days. Results: MTT assay results showed that both L-PRF and i-PRF increased DPSC proliferation relative to the control group. After 7 days in L-PRF and i-PRF CM, DPSCs exhibited increased ALP activity, higher red-colored calcium deposits with ARS staining, and elevated levels of VEGF and TGF-beta. In addition, higher concentrations of inflammatory cytokines IL-6 and IL-8 were observed in both L-PRF and i-PRF compared to the control. Conclusions: Using both L-PRF and i-PRF as scaffolds can enhance the osteoinductive ability of stem cells, offering a potential strategy for regenerative therapies.