If you do not replace your missing tooth with a dental implant, it is possible that your neighbouring teeth will shift and collapse into the gap.
This will in-turn lead to an imbalanced bite with some teeth subjected to more stress from your bite as compared to others, resulting in unequal wear and tear!
You will naturally chew more on the side with more teeth and the rate of wear and tear on the side that you favour will be significantly increased.
All these issues may not give rise to symptoms in the beginning, but over time, the teeth that have more wear and tear may have stress cracks, accelerated enamel wear and/or sensitivity leading on possibly to a full blown toothache. This would require extensive treatment that could potentially incur a higher cost than if you were to do the implant in the beginning!
Therefore, it is always advisable to replace missing teeth with dental implants to recreate balance to the bite and to ensure that the bite forces are distributed evenly to as many teeth as possible.
