Asymptomatic tooth with cracks/conflicting advice

[ShingleSt]

Here is my situation: In 2002, on a routine dental visit, I was diagnosed with a lingual crack in one of my upper back molars, which already had a large restoration (placed in childhood and replaced in 1992 by my current dentist). He said he would watch it for a while, since it was asymptomatic. Over the course of the last 11 years, additional cracks have appeared in the buccal, distal, and as of last year, mesial parts of the tooth. My dentist has watched the tooth over the course of that time, and because it is now “a starburst pattern,” as he describes it, he would like to remove the restoration and potentially do a crown. The only reason I have hesitated in following his advice (I trust him very much) is because I have been completely asymptomatic the entire stretch of time (no biting-down sensitivity, no sensitivity to hot and cold).

His point is that the tooth will eventually crack further and definitely cause symptoms, perhaps requiring a root canal or extraction in the future. He says that a crown placed prophylactically will protect the tooth and give me potentially many more years of life for that tooth. After reading some dental-study articles online, I became more confused than enlightened. One article (a survey of the dental literature the Journal of Esthetic and Restorative Dentistry) pointed out that although it is well-accepted practice to crown all cracked teeth, there is no evidence in the literature to support that this positively affects outcomes. Also, another article gave detailed descriptions of various cracks in the enamel and dentin of molars after magnification; some of those categories seemed to indicate that you can have various kinds of cracks in the enamel only, which do not go into the dentin, even in restored molars (and would not necessarily require drastic action).

I am pretty sure I will go ahead and have him remove the restoration, inspect what’s hiding in there (although I’m sure he won’t be using a microscope, which I take it is the tool of choice), and place a crown. However, how much possibility is that there that the trauma of removing the large filling and additional drilling will just make the situation worse, including affecting the pulp? I would not have any of these questions if I had had any symptoms up to this point. I would definitely just be going forward with the procedure.