Autophagy: A boon or bane in oral cancer.

Autophagy is a catabolic process involving cellular recycling and is believed to play a distinct role in cell survival especially when exposed to stressors, rendering it comparable to the elixir sustaining life. It plays a significant role in various conditions like cancers, neuropathies, heart diseases, auto-immune diseases, etc. Its role in tumorigenesis and cancer therapeutics is worth exploring. Autophagy is believed to help in survival and longevity of cancer cells by buffering metabolic stress. Inhibition of autophagy in an environment of nutrient deprivation leads to cell death. Autophagy is also seen to facilitate metastasizing tumor cells in surviving the conditions of metabolic deprivation and in recovery when conditions turn favorable. Many current cancer therapies tend to inflict metabolic stress, thus autophagy inhibitors may be useful in cancer treatment. As per the adage, "excess of anything is bad", the autophagy promoters can also be exploited as beneficial tools in the fight against cancer. Another method for tumor-cell elimination can be by inducing autophagic cell death through over-stimulation. Oral cancers are becoming a leading cause of deaths worldwide. Much remains to be explored about the role autophagy plays in progression of head and neck cancers, so as to harness it in the therapeutics of these cancers. Research on autophagy is still in its infancy. There are knowledge gaps in understanding this complex process. But there is no doubt that understanding exact mechanism behind autophagy will open up new avenues in cancer therapeutics and even prevention.

A comparative evaluation of microleakage around class V cavities restored with different tooth colored restorative materials.

OBJECTIVES: To evaluate and compare microleakage around class V cavities restored with silorane and dimethacrylate-based composite resins. METHODS: Standard Class V cavities were prepared on the buccal surface of 60 non-carious human molars. Teeth were randomly divided into 3 groups (n=20) depending on the restorative materials used, Silorane-based composite resin (Filtek P90-SIL), dimethacrylate-based composite resin (Solare P-SOLP) and light-cure glass ionomer cement (GC Fuji II LC -LCGIC). The restored teeth with these tooth-coloured restorative materials were thermo-cycled and then immersed in 2% Rhodamine B dye under vacuum pressure for 48 hours. All teeth were bisected longitudinally in a bucco-lingual direction and observed under stereo-microscope at 30X magnification for the evidence of dye penetration. The data were analysed using one-way analysis of variance (ANOVA) and Tukey's Post Hoc tests (α=0.05). RESULTS: SIL composite resin showed the least microleakage in Class V cavity restorations with a statistically significant difference to SOLP and LCGIC. Sixty five percent of specimens in SIL group, 30% in SOLP group and 5% in LCGIC group showed dye penetration up to one-third of the cavity depth, while 5% in SIL group, 5% in SOLP group and 35% in LCGIC group showed dye penetration up to two-thirds of the cavity depth, and 30% in SIL group, 65% in SOLP group and 60% in LCGIC group showed dye penetration up to the axial wall. CONCLUSIONS: Silorane-based composite exhibited least microleakage in restoring class V cavities compared to dimethacrylate-based composite resin and light-cured glass ionomer cement.