Gary R. Hartwell

Clinical investigation of in vivo endodontically treated mandibular and maxillary molars

A clinical in vivo study of endodontically treated mandibular and maxillary molars was conducted. It showed that four canals were more readily detected and obturated in mandibular molars compared with maxillary molars. Obturation of mandibular molars with four canals compared favorably with in vitro studies. However, a discrepancy was observed when four canal maxillary molar obturation was compared with those in vitro studies. Access preparation should be reevaluated to facilitate the search and location of the fourth canal in maxillary molars, which may frequently escape detection. It is almost axiomatic to accept the fact that the root system of the mesiobuccal root of maxillary molars and the distal root of mandibular molars frequently have a root canal system containing more than one canal. This fact has led to an awareness that is reflected in our routine practice of clinical endodontics. It is primarily manifested in our access preparations, which are now designed to aid in the location of the fourth canal frequently associated with mandibular and maxillary molars. Ultimately, this awareness f~cilitates cleaning and shaping as well as obturating the root canal system.

Placement of Mineral Trioxide Aggregate Using Two Different Techniques

The purpose of this study was to determine if the adaptation of mineral trioxide aggregate (MTA) would differ when placed into simulated root canals of varying length when using two different placement and condensation methods. Hand condensation was compared to ultrasonic condensation. Eighty polyethylene tubes were divided into four groups of 20 tubes each. The tubes in the four groups were prepared to receive 3-, 5-, 7-, and 10-mm lengths of MTA respectively. Each group of 20 tubes was subdivided; 10 samples of each length had MTA placed and condensed by the hand method and the other 10 by the ultrasonic method. After condensation the samples were evaluated with a light microscope and radiographs for the degree of adaptation of the MTA to the tube walls and for the presence of voids within the MTA material itself. The results demonstrated an 80% agreement for findings between the light microscopy and radiographic evaluation. Hand condensation resulted in better adaptation to the tube walls and less voids than the ultrasonic method. There was no significant difference in the results for any of the four lengths of MTA placed by the hand method (p > 0.9). At this time hand condensation should be considered the preferred method for placement of MTA.

Frequency of Second Mesiobuccal Canals in Maxillary Molars as Determined by Use of an Operating Microscope: A Clinical Study

Operating microscopes have recently been introduced to facilitate treatment of surgical and nonsurgical endodontic cases. The aim of this study was to determine in an in vivo clinical study if the use of an operating microscope would increase the number of second mesiobuccal canals located and obturated in maxillary first and second molars. Two hundred maxillary first and second molars treated with the aid of a microscope were evaluated. The number of second mesiobuccal canals that could be negotiated and obturated within 4 mm of the apex was recorded. Thirty percent of all maxillary molars had a negotiable second mesiobuccal canal. Evaluated separately, 33.1% of the maxillary first molars and 24.3% of the second molars had a negotiable second mesiobuccal canal. Results indicated that use of a surgical microscope did not increase the number of second mesiobuccal canals located, compared with those reports where access preparations were modified and the microscope was not used.

Antibiotic use by members of the American Association of Endodontists in the year 2000: report of a national survey.

The purpose of this study was to determine the prescribing habits of active members of the American Association of Endodontists (AAE) with regard to antibiotics. A one-page, double-sided questionnaire was sent to the active members of the AAE living in the United States. The 1999 mailing list of 3203 members was obtained from the AAE, and the return rate was 50.1% (1606 surveys). With a sample size over 1000, the study was able to distinguish differences to within 0.5% with power = 80% (at alpha = 5%). The data were analyzed using descriptive statistics and chi-square tests of independence. Penicillin VK, 500 mg, 4 times a day, was the first choice antibiotic prescribed by 61.48% of respondents. Clindamycin (Cleocin), 150 mg, 4 times a day, was selected by 29.59%. For those patients with a penicillin allergy, 57.03% prescribed clindamycin and various erythromycin preparations were prescribed by 26.65%. A loading dose was used by 85.14%. The average duration of antibiotic therapy was 7.58 days. Those respondents involved in academics, either part-time or full-time, were significantly more likely to prescribe penicillin VK, 500 mg, 4 times a day at a rate of 85% versus those in part-time or full-time private practice at a rate of 67%. For cases of irreversible pulpitis, 16.76% of responding endodontists prescribed antibiotics. For the scenario of a necrotic pulp, acute apical periodontitis, and no swelling, 53.93% prescribed antibiotics. Almost 12% prescribed antibiotics for necrotic pulps with chronic apical periodontitis and a sinus tract. For the most part, the majority of the members of the AAE were selecting the appropriate antibiotic for use in orofacial infections, but there are still many who are prescribing antibiotics inappropriately. Although there were trends of improvement in some areas with regards to prescribing antibiotics, there were other areas where there had been no improvement in 25 years. Unless these trends change, our generation and those to come may not have effective antibiotics for use in the management of true orofacial infections.

Leakage in vitro with IRM, high copper amalgam, and EBA cement as retrofilling materials

An in vitro dye leakage study was performed to compare the sealing ability of high copper amalgam with Copalite, IRM, and EBA cement when used as retrofilling materials. Fifty-one extracted anterior teeth were instrumented and then obturated with gutta-percha. The apical 3 mm of the roots were resected and 2-mm deep apical preparations were made. The roots were then randomly placed into three groups and retrofilled with one of the experimental materials. After 72 h in India ink, the teeth were cleared and evaluated for leakage with a stereomicroscope. No leakage was evident in the three teeth used as negative controls and complete leakage was noted in the three positive control teeth. Statistical analysis showed that IRM and EBA cement had significantly less leakage than amalgam with Copalite. The difference between the EBA cement and IRM was not significant.

Maxillary first molar with six canals.

A case report is presented concerning a maxillary first molar with six canals. The morphology is unique because it is characterized by two canals in the mesiobuccal root, two in the distobuccal root, and two in the palatal root.

Detection and treatment of multiple canals in mandibular premolars

The endodontic treatment of mandibular premolars may not be successful because of failure to recognize and/or treat multiple canals when they are present in these teeth. Factors such as an awareness of data pertaining to the number of canals, knowledge of canal morphology, correct radiographic interpretation, and tactile examination of canal walls are important in detecting the presence of multiple canals. These factors, as well as guidelines for subsequent canal preparation and obturation, are provided.

Identify and Define All Diagnostic Terms for Periapical/ Periradicular Health and Disease States

INTRODUCTION The purpose of this in-depth investigation was to identify, clarify, and substantiate clinical terminology relative to apical/periapical/periradicular diagnostic states, which is used routinely in the provision of endodontic care. Furthermore, the information gleaned from this investigation was used to link diagnostic categories to symptoms, pathogenesis, treatment, and prognosis wherever possible, along with establishing the basis for the metrics used in this diagnostic process. MATERIALS AND METHODS Diagnostic terminologies and their relevance to clinical situations were procured from extensive historic and electronic searches and correlated with contemporary concepts in disease processes, clinical assessments, histologic findings (if appropriate), and standardized definitions that have been promulgated and promoted for use in the last 25 years in educational programs and test constructions and for third-party concerns. RESULTS In general, clinical terminology that is used routinely in the practice of endodontics is not based on the findings of scientific investigations. The diagnostic terms are based on assumptions by correlating certain signs, symptoms, and radiographic findings with what is presumed (not proven) to be the underlying disease process of a given clinical state. There were no studies that specifically tried to assess the accuracy of the metrics used contemporarily for the classification of clinical disease states. CONCLUSION A succinct diagnostic scheme that could be described thoroughly, agreed on unanimously, coded succinctly for easy electronic input, and ultimately used for follow-up analysis would not only drive treatment modalities more accurately, but would also allow for future outcomes assessment and validation.

Radiographic evaluation of root canal anatomy of in vivo endodontically treated maxillary premolars.

A radiographic in vivo study was undertaken to investigate the root canal systems of the maxillary first and second premolars. This study reveals that the frequency of two-canaled maxillary first premolars compared favorably with previous studies. However, multiple canal systems were found with greater frequency in maxillary second premolars than had previously been reported.

The impact of improved access and searching techniques on detection of the mesiolingual canal in maxillary molars

A clinical radiographic study of endodontically treated maxillary first and second molars was conducted. The study revealed that modifying the access preparation resulted in a definite increase in the number of mesiolingual canals located and obturated.