F.-M. Huang, K.-W. Tai, M.-Y. Chou & Y.-C. Chang
Department of Dentistry, Chung Shan Medical and Dental College Hospital
School of Dentistry, Chung Shan Medical and Dental College, Taichung, Taiwan.

Aim.
The purpose of this study was to determine the cytotoxicity of three different types of root canal sealer on human periodontal ligament (PDL) cells and a permanent hamster cell line (V79 cells).

Conclusions.
The sensitivity of toxicity depended on the materials tested and the cell culture system used. Thus, the use of both permanent and primary cells is recommended for screening of the cytotoxic effects of root canal sealers. In addition, the results confirmed that root canal sealers constantly dissolve when exposed to an aqueous environment for extended periods, possibly causing moderate or severe cytotoxic reactions. Use of calcium hydroxide-based material as a root canal sealer initially may result in a more favourable response to periradicular tissues.

E. Cotti, G. Campisi, V. Garau& G. Puddu
Departments of Conservative Dentistry and Endodontics and Oral Surgery, School of Dentistry, University of Cagliari.
Department of Radiology, Hospital “G. Brotzu”, Cagliari, Italy.

Aim.
This study describes the use of a real time-ultrasound imaging technique (echography) for the study of periradicular lesions.

Conclusions.
The antecedent allegation from this abstraction advance that echography is an simple and reproducible address that has the abeyant to supplement accepted radiography in the analysis and aftereffect of all-encompassing periapical lesions. It provides specific advice on the admeasurement of the bane and has a low radiation risk. Furthermore, its abeyant to call the capacity of the lesions (i.e. adulterated against corpuscolated) and their vascularization may become an important agency if authoritative a cogwheel analysis amid lesions of endodontic agent (i.e. granulomas against cysts) and aswell amid added lesions of the maxillary bones. More studies are currently getting agitated out.

O. Molven, A. Halse, I. Fristad
Department of Odontology, Endodontics, and Radiology, School of Dentistry, University of Bergen, Norway.

Aim.
The aim of this study was to evaluate and compare the long-term diagnostic consistency of two examiners, an endodontist and a radiologist, and to make comparisons with findings recorded by an observer with more recent scientific and clinical experience in endodontics. the observers.

Conclusions.
The long-term reliability of the two original observers was judged as being satisfactory. All three observers judged the overall disease status of the material in the same way. The joint discussions of selected cases might reduce observer variation to an acceptable level, avoid a number of false recordings and increase the reliability and validity of the findings.

Hauman CHJ, Chandler NP, Tong DC.
Departments of Oral Rehabilitation and Stomatology, School of Dentistry, University of Otago, Dunedin, New Zealand.

The anatomical and clinical significance of the maxillary
sinus in relation to conventional and surgical endodontictherapy is considered. The discussion includes a review on the development, anatomy and physiology of the maxillary sinus, the diagnostic evaluation of the sinus and the differential diagnosis of sinusitis. Endodontic implications of the maxillary sinus include extension of periapical infections into the sinus, the introduction of endodontic instruments and materials beyond the apices of teeth in close proximity to the sinus and the risks and complications associated with endodontic surgery.

M. D. Öztan
Department of Endodontics, Faculty of Dentistry, Ankara University, Ankara, Turkey

Aim.
To report the healing of a large periapical lesion following non-surgical root canal treatment.

Summary.
A 12-year-old male with a large periapical lesion around the apices of his mandibular incisors is described. The lesion formed after trauma to the mandibular anterior teeth 5 years previously. During root canal treatment, chlorhexidine gluconate was used for irrigation, and calcium hydroxide was used both for the intracanal dressing and as a base of the root canal sealer. Periapical healing was observed 3 months after obturation and continued at the 12-month review.

Key learning points.
- Root canal treatment, including the use of chlorhexidine gluconate and calcium hydroxide for infection control, led to substantial healing of a large periapical lesion.
- This report confirms that large periapical lesions can respond favourably to non-surgical treatment.