A. Y. Kaufman, S. Keila & M. Yoshpe
Departments of Endodontology and Oral Biology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
Israel Defense Forces.

Aim.
The purpose of this study was to test in an in vitro model the accuracy of a Bingo 1020 electronic apex locator, to compare the results to those of a well known apex locator, Root ZX, as well as to those of the radiographic method of tooth length determination.

Conclusions.

1. Bingo 1020 is a user friendly apex locator and is distinguished by its advanced user interface and the large and clear graphic screen, which shows a realistic display of the file advancement throughout the root canal length.
   
2. Bingo 1020 measured the tooth length within a clinically acceptable range.
   
3. The content of the root canal influenced the results of the measurements with both EALs, but the differences were not clinically significant.
   
4. Measurements obtained using the Bingo 1020 were closer to the actual length than those obtained by the Root ZX but this had no clinical significance.
   
5. Verification of tooth length through electronic measurements indicated they were closer to the actual length than those obtained radiographically. Radiographic measurements are usually longer than the actual length.

T. Ataoglu, M. Üngör, B. Serpek, S. Haliloglu, H. Ataoglu  & H. Ari
Departments of Periodontology,  Endodontics, and Maxillofacial Surgery, Dentistry Faculty
Department of Biochemistry, Veterinary Faculty, Selcuk University, Konya, Turkey

Aim.
The aim of this study was to determine IL-1 and TNF- levels in periapical exudates and to evaluate their relationship with clinical and radiological findings.

Conclusions.
It is apparent that the progression of periapical granulomas is accompanied by the rate at which their surrounding bone is destroyed. The results of the present study suggest that IL-1is more important than TNF-in periapical bone resorbing activity. Within the limitations of this study, it is concluded that periapical exudate levels of both cytokine are not able to reflect periapical disease state.

T. Castrisos & P. V. Abbott
School of Dental Science, University of Melbourne, Melbourne, Victoria, Australia

Aim.
The aims of this study were to determine the attitudes of endodontists toward the risk of root fracture when removing posts and to determine which methods they commonly used to remove posts from root-filled teeth.

Conclusions.
The general conclusions derived from this survey were:

1. When a post is present in a tooth requiring root canal retreatment, most endodontists surveyed preferred to remove the post rather than perform periapical surgery.
   
2. Endodontists were only concerned about root fracture in teeth with wide posts and thin root dentine.
   
3. Root fractures have rarely occurred during post removal, with a frequency of less than 0.002% of the estimated number of posts removed by the endodontists surveyed.
   
4. The most common method used to remove posts was ultrasonic vibration, whilst the Eggler post remover was the most commonly used device, particularly for removing cast post and cores in anterior teeth.

S. Shibata, S. Yoneda, M. Yanagishita & Y. Yamashita
Departments of Maxillofacial Anatomy,  Cariology and Operative Dentistry and Biochemistry, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan

Aim.
The main aim of this study was to investigate the developmental changes in the distribution patterns of hyaluronan (HA) and versican in postnatal rat molar dental pulp, in order to confirm the hypothesis that the distribution of both molecules can vary with physiological conditions in the dental pulp.

Conclusions.
Distribution of hyaluronan and versican in the dental pulp varied with age and also showed regional differences between the coronal and the radicular pulp, and this supports the hypothesis described above.