Related Experiment Video
Updated: Feb 14, 2026

Reduced Itraconazole Concentration and Durations Are Successful in Treating Batrachochytrium dendrobatidis Infection in Amphibians
Published on: March 14, 2014
12-month Success of Cracked Teeth Treated with Orthograde Root Canal Treatment
Keith V Krell1, Daniel J Caplan2
1Department of Endodontics, University of Iowa, Iowa City, Iowa.
Introduction:
Long-term studies examining the treatment outcomes of "cracked teeth" that received orthograde root canal treatment in the United States do not exist. The purpose of the present study was to examine the distribution and 1-year treatment outcomes of cracked teeth receiving orthograde root canal treatment in 1 private endodontic practice over a 25-year period.
Methods:
A total of 3038 cracked teeth were initially examined, and data from 2086 unique patients were analyzed. Pulpal and periapical diagnoses, year of treatment, tooth type, restorative material, and number of restored surfaces at the time of examination were recorded for all patients. Periodontal probing depths were also recorded. The patients' age and sex were added retrospectively for all patients whose data were available. Univariate frequency distributions for all collected variables were evaluated. Bivariate associations were analyzed between explanatory variables and the success of the root canal therapy.
Results:
Of the 2086 cracked teeth observed among unique patients, the most common were mandibular second molars (36%) followed by mandibular first molars (27%) and maxillary first molars (18%). Among the 363 teeth eligible for multivariable regression analysis, 296 (82%) were deemed successes after 1 year. There were no statistically significant differences in success based on pulpal diagnosis (irreversible pulpitis, 85%; necrosis, 80%; previously treated, 74%), patients' age, sex, year of treatment, tooth type, restorative material, or number of restored surfaces at the time of examination. The 3 factors most significant in bivariate analyses were pocket depth, distal marginal ridge crack, and periapical diagnosis, which were used to generate a prognostic index for success of orthograde root canal therapy in cracked teeth called the Iowa Staging Index.
Conclusions:
The results of this study suggest that cracked teeth that received root canal treatment can have prognoses at higher success rates than previously reported. The Iowa Staging Index may prove to be useful in clinical treatment decision making.
Related Concept Videos
Ecological Succession
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Types of Non-structural Cracks in Concrete
Plastic shrinkage cracks typically form within hours after the concrete is poured. The concrete's surface dries faster than the bottom, creating tensile stress that the still-plastic concrete cannot withstand, leading to diagonal or randomly patterned cracks on the concrete surface.
Primary and Secondary Growth in Roots and Shoots
Root Mean Square
For example, consider the velocity of gas molecules in a container. The gas molecules are moving in different directions, which might impart positive and negative...
Properties of the Root Locus
To determine if a point lies on the root locus, the criterion involves the sum of angles contributed by all poles and zeros to that point. Specifically, this sum must be an odd multiple of 180 degrees. The gain at any point on...

