Purpose The prime factor in determining the success of reimplantation of an avulsed tooth is the maintenance of the viability of periodontal ligament fibroblast cells (PDFC). This study aims to evaluate and compare Mc Carey Kaufman media (MK), Cornisol, Dulbecco’s Modified Eagles Medium (DMEM), Hanks Balanced Salt Solution (HBSS) and distilled water in preserving the viability of the PDFC using the Cell Counting Kit-8 assay (CCK-8). Methods Cryopreserved PDFC were suspended in DMEM and incubated in CO 2 incubator at 370C with 95% humidity and 5% CO 2 for attachment. Once cells attained 80% confluence, they were trypsinised and passed into T-25 culture flasks to expand the culture population. Cells from passage 5 were pooled for experimentation. Trypan blue exclusion test was performed before each experiment to measure cell viability and batches showing more than 95% viability were used in the experiment. The viable PDFC with 1×105 were seeded in 96 well plates and incubated in CO 2 incubator at 370C, 95% humidity and 5% CO 2 for 24 hours to allow cell attachment. A 100µL of the experimental media were added in the wells and the cells were exposed for 1, 24 and 48 hours respectively. The viability was determined using the CCK-8. Experiment was performed in triplicates and data was subjected to statistical analysis. Results Statistical analysis was performed using repeated measure ANOVA, ANOVA, and post-hoc Bonferroni test with the significance level p<0.05. The values are as follows: MK (1.3146 ±0.0588, 1.9012±0.0511, 2.0723±0.1211) > Cornisol (1.2399±0.0548, 1.9596±0.0652, 1.9592±0.1361) >DMEM (1.1914±0.0691, 1.8479±0.0116, 2.0718±0.0795) > HBSS (0.3665±0.0814, 0.0184±0.0010, 0.0248±0.0042) >distilled water (0.0122±0.0033, 0.0225±0.0085, 0.0104±0.0008) at 1 hour, 24 hours and 48 hours respectively. MK >Cornisol>DMEM>HBSS>distilled water. Conclusion It can be concluded that the corneal preservation solutions showed promising results in preserving periodontal ligament cell viability for extended time periods.

Objective: The study aimed to evaluate the variations in the RCM of mandibular first premolars (MFP) in south Indians and also evaluated the gender dimorphism and contralateral symmetry of the pattern. Methods: 200 Cone Beam Computed Tomography (CBCT) images of MFP of patients above 18 years were analyzed for the root canal morphology after excluding the distorted images, endodontically treated tooth or fractured root. The teeth were carefully evaluated in cross-sectional, axial and coronal sections and the information regarding the number of roots and the type of root canal as per Vertucci’s classification. Interobserver and intraobserver reliability were also checked. Results: Single rooted teeth with Type I (73.01%) variation was the most prevalent pattern observed in the study population, which was followed by Type III (14.11%) and Type V (5.52%), respectively. Type IV and Type VIII variations were not found in our study. Conclusions: In both males and females, type I configuration was the most common pattern with symmetry in contralateral mandibular single-rooted first premolars.