It’s not super clear what you’re getting at here. The choice isn’t teflon or oil. Everyone uses fat to sear food in a pan, whether or not it’s a nonstick pan. Cooking with a high-smoke-point oil which is low in saturated fat, such as avocado oil, with stainless steel, is strictly better than cooking with teflon pans by every measurable health metric.
Searing food in a PTFE pan almost certainly involves overheating it. Depending on what you're cooking you don't necessarily need oil (e.g. you don't need it for cooking eggs), although you might want to use some at moderate temperature for flavor. And for some foods oil is necessary to avoid overheating the pan, because it improves heat transfer from the pan to the food. Check with an IR thermometer every time you cook something new.
