The TCase for this processor is 105 degrees Celsius as you mentioned.
The TCase is a number established by Intel® as a point of reference in order to understand what could be expected as per normal processor temperature.
Anything from the TCase and below will be the expected temperature of the processor in normal use, anything that doesn't stress out the processor (watching movies, burning CDs, browsing the internet, creating documents, etc.) When the processor is stressed out meaning that you are running heavy processor applications that take control of the CPU or uses it at 100% the temperature will go beyond the TCase. It can perfectly reach 110 to 115 degrees and the processor will still be OK. The cooling fan is in charge to keep that temperature there.
If the processor temperature reaches 125 degrees or higher it will send a signal to the motherboard to shut down to prevent mayor damages and most likely it won't be possible to turn the computer back on until it cools down.
The normal processor temperature will depend on the chassis type, the hardware involved and the location of the computer, and it usually is lower than the TCase.
So at this point 104 degrees Celsius is still OK for the processor.