Diagnosis and treatment of teeth with longitudinal fractures is challenging. Cracks are usually not visible radiographically; they require a thorough evaluation to aid in diagnosis. Patients may be asymptomatic, demanding the dentist rely on clinical findings to make a diagnosis. Early diagnosis of the presence and extent of a crack is essential for the successful management of a cracked tooth. There is limited information in the literature regarding the prevalence or predictive factors of cracks extending into the pulp chamber of teeth. The purpose of this study was to determine the prevalence of intrapulpal cracks in maxillary molars and to identify factors that may aid in diagnosing the existence of a crack. All maxillary molar teeth requiring non- surgical root canal therapy or retreatment at the Virginia Commonwealth University graduate endodontic clinic from June 2016 through December 2016 were included in the study after obtaining patient consent. Teeth were examined visually, transilluminated, stained, and examined microscopically for the presence of an intrapulpal crack. Demographic information, subjective data associated with the chief complaint, objective results of diagnostic testing (percussion, palpation, bite stick test, transillumination, probing depths, existing restorations, and diagnosis) were analyzed using chi-square and logistic regression (p<0.05) to identify associations of these findings with the existence of a crack. A total of 18% (15/82 teeth) of maxillary molars that were evaluated and had endodontic treatment initiated were cracked. There was a significant association between cracked teeth and pain on biting (P<.0001) and with probing depths greater than 4 millimeters (mm) (P < 0.003). Those positive on a tooth slooth test were more likely to have an intrapulpal crack (P<.001) and teeth with a positive transillumination test were also found to be associated with the presence of a crack(P < .001).

Few studies have reported the incidence or prevalence of cracked teeth with pulpal involvement. No attempts have been made to evaluate the prevalence or clinical predictors for intrapulpal cracks. The purpose of this study was to investigate the prevalence of intrapulpal cracks in first and second mandibular molars and to determine if clinical findings are predictive for the existence of intrapulpal cracks. First and second mandibular molars (190) requiring non-surgical root canal treatment at the VCU Graduate Endodontic Practice between February 15, 2013 and August 15, 2013 were analyzed retrospectively. Teeth were transilluminated, stained, and inspected for intrapulpal cracks using a dental microscope. Data gathered included: demographics, subjective and objective information regarding the chief complaint to include bite stick test, transillumination, probing depths greater than 4mm, existing restorations, and diagnosis. Chi-square and logistic regression were performed (p<0.05). The prevalence of intrapulpal cracks in first and second mandibular molars combined was 9% (17/190, 95%CI= 5.7% to 13.9%). The prevalence was 7% for 1st molars and 13% for 2nd molars. There was no statically significant difference in the prevalence between first and second mandibular molars. Individual characteristics predictive for the existence of intrapulpal cracks were age, probing depth greater than 4mm, transillumination and a positive Tooth Slooth™ test (all p<0.05). Staining of the pulp chamber after access identified only one of 17 intrapulpal cracks. Staining of the pulp chamber did not significantly increase the ability to identify intrapulpal cracks. Neither diagnosis, sex, nor existing restorations were significant predictors for intrapulpal cracks. Probing depth greater than 4mm, age over 40 and a positive Tooth Slooth™ test were conjointly significant for predicting intrapulpal cracks.

Few studies have investigated cracks involving the pulp chamber walls or floor. The purpose of this study was to create a classification system for intrapulpal cracks and analyze associated clinical characteristics. Retrospective analysis included 52 teeth confirmed to have an intrapulpal crack. The classification system describes the crack based upon its location within the pulpal walls and floor. Documentation consisted of demographic, subjective and objective examination data. Chi-squared analysis tested associations with the intrapulpal crack classifications. Ninety-two percent of intrapulpal cracks run M-D, 75% involve one pulp chamber wall, and 84% terminate at the floor-wall junction or extend into an orifice without involving the pulpal floor. There was a statistically significant (P<0.05) relationship between the location of the intrapulpal crack and tooth type as well as between the classification system and bite test and transillumination. The classification system was adaptable to clinical practice and provides insight into these challenging situations.