The purpose of this study is to identify pre-operative factors that put patients at greater risk of developing severe tooth pain following root canal therapy, thereby providing evidence that will allow dentists to act preventively to lessen this risk, improve pain control, increase their patients' quality of life, and decrease the number of dental emergency interactions.

A parallel goal of this study is to assess the feasibility of recruiting dentists that provide root canal therapy and patients using the DPBRN.

Goals for this study is to:

• Assess the frequency and intensity of pre-operative pain
• Evaluate the occurence and intensity of intra-operative pain
• Evaluate the occurence and intensity of post-operative pain
• Assess the interference of persistent tooth pain with daily life
• Identify a limited set of risk factors related to the development of post-operative pain.

Inclusion Criteria:

• 19-70 years old
• permanent adult tooth requiring it first non-surgical root canal therapy
• patients with more than 1 tooth requiring root canal therapy are eligible, but only the first root canal procedure performed will be included to avoid problems of correlation within patients

Exclusion Criteria:

• Evidence of prior root canal therapy, including iatrogenic, but not disease-induced, pulp access of the tooth being considered
• patients with obvious cognitive impairments (e.g., past stroke with communication deficits, dementia, mental disability)
• patients unable to return for 6 month follow-up, since another study plans to obtain data of these patients at that time (DPBRN Persistent Tooth Pain)

The participants directly involved in this study are patients who have sought dental treatment in the practitioner-investigators' practices. The practitioner-investigators will be endodontists and general dentists.