If you do not currently have dental insurance and you need a dental bridge, then cost can be a factor.  Buying dental insurance to reduce the cost is a good idea.  However make sure you are buying the right plan for this need.  Normally dental insurance plans such as PPO or Indemnity will have long term waiting periods for dental services such as bridges. 

That is important to understand that if you buy these types of dental insurance plans in order to stay with your current dental provider,  you may not have any benefits for the dental service you currently need.  When buying PPO or Indemnity plan it best to think ahead and have it in force prior to any major dental issues.