DR. ABDALLAH AL-SHARIF
Riyadh Al Kharj Military Hospital, Riyadh, Saudi Arabia

When endodontic treatment fails, surgical or nonsurgical endodontic retreatment is often performed. Surgical endodontic therapy is an important part of endodontic practice and it may be undertaken after unsuccessful orthograde retreatment or when orthograde retreatment is impossible or unfavorable. When an initial surgical intervention or a surgical retreatment fails, the best treatment strategy to correct the problem should be determined after a through and meticulous examination of possible causes for the failure. Clinical studies have demonstrated that the infection at the time of the root filling, the size of periapical lesion, and the level of root filling at the radiographic apex influence the prognosis of endodontic retreatment. The aim of the presentation is to present the factor that affecting the success or failure of the retreatment.
Saudi Dental Journal 2006;18(SI)-Abstr.036

037.The role of root canal sealer in successful endodontics

DR. ZAKI A. MALALLAH

Dental Department,Hamad Medical Corporation, Doha, Qatar.

Teeth with pulpal or periapical inflammation can be successfully treated with the established techniques of cleaning and shaping of root canals, followed by obturation of the root canal system. Long term success in endodontic therapy mainly depends on achieving hermetic seal at the apical end of the root canal and this is achieved by solid core filling material with root canal sealer.

A large variety of root canal sealers have been advocated for use, in conjunction with solid or semisolid filling materials. Currently, root canal sealers are available on various formulas such as epoxy resin, calcium hydroxide and zinc oxide-eugenol.

The properties of the root canal sealers can be classified as physico-chemical, antimicrobial and biological. Ideally, root canal sealers should be biocompatible (well tolerated by the periradicular tissues). A biocompatible sealer should neither prevent nor hinder tissue repair, but should aid or stimulate tissue regeneration.

Sealing properties of root canal sealers are of vital importance for the success of root canal treatment. Adhesion of a root canal sealer means its capacity to attach to the dentinal walls of the root canal and provide bonding between it and GP points.

The most commonly used methods for microbial control include instrumentation, irrigation, intracanal dressing, adequate filling and by the antibacterial activity of root canal sealers that contain substances such as paraformaldehyde, eugenol and thymol, that help to destroy the remaining bacteria. On the other hand, severe toxicity of such sealer may be a reason for damage of periapical issues, thereby abolishing the beneficial effects of the antimicrobial properties of the material.
Saudi Dental Journal 2006;18(SI)-Abstr.037

DR. OMAR ABDEL SADEK EL MELIGY*

DR. DAVID R. AVERY**

*Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia

**School of Dentistry, Indiana University,Indianapolis, Indiana, USA

Purpose: The aim of this study was to compare mineral trioxide aggregate (MTA) with calcium hydroxide [Ca (OH)₂] clinically and radiographically as materials to induce root-end closure in necrotic permanent teeth with immature apices (Apexification).

Methods: Fifteen children, each with at least 2 necrotic permanent teeth requiring root-end closure (apexification), were selected for this study. All selected teeth were evenly divided into 2 test groups. In group I, the conventional calcium hydroxide apexification (control) was performed, whereas in group II, the MTA apexification (experimental) was done. The children were recalled for clinical and radiographic evaluations after 3, 6, and 12 months.

Results: The follow-up evaluations revealed failure due to persistent periradicular inflammation and tenderness to percussion detected at 6 and 12 months postoperative evaluation in only 2 teeth treated with calcium hydroxide. The remaining 13 teeth appeared to be clinically and radiographically successful 12 months postoperatively. None of the MTA-treated teeth showed any clinical or radiographic pathology.

Conclusions: MTA showed clinical and radiographic success as a material used to induce root-end closure and seems to be a suitable replacement for calcium hydroxide in necrotic immature permanent teeth.
Saudi Dental Journal 2006;18(SI)-Abstr.038

039.Orthognathic surgery: Implication of TMJ

DR. BISHI AL-GARNI 
 Riyadh Dental Center, Riyadh Medical Complex, Riyadh, Saudi Arabia

Introduction: In post-orthognathic surgery, there are some local changes in the soft tissues and bony changes. One of these changes is the tempromandibular change wherein there is an early and late change.

Material and Methods: A survey of the patients who had orthognathic surgery for single or double jaws surgery, analysis for the symptoms and signs will be presented. Radiological and clinical changes for the last few years will be discussed.

Discussion: The changes in the position of the condyle, radiologically and intraoperatively, post lefort I Osteotomy and BSSO of the mandible, the Progressive Condylar Resorption (PCR) will be presented including its etiology and manifestations, predisposing factors, and the managements for this complications.

Conclusion: The TMJ function and stability in orthognathic surgery depends on the management of the surgeon, not only in the selection of the surgical technique.
Saudi Dental Journal 2006;18(SI)-Abstr.039

DR. GHASSAN A. DHAIF

Salmaniya Medical Complex, Kingdom of Bahrain

An adequate transverse maxillary dimension is a critical component of a stable and functional occlusion. Rapid palatal expansion appliances have been used effectively to correct maxillary transverse deficiency in skeletally mature patients. However, in adults, attempts at rapid palatal expansion are frequently associated with failure due to skeletal maturity, bony interdigitation and sutural fusion. This often results in difficulties in separating the maxilla with orthopedic forces alone, bending of the alveolus, lateral tipping of the teeth, inability to open the alveolus, lateral pressure necrosis of the mucosa from the expansion appliance and relapse. Furthermore, treatment of unilateral crossbites is ineffective by conventional method due to bilateral effect.

Various surgical techniques including surgically-assistance rapid palatal expansion (SARPE) and segmental lefort I osteotomies have been described in the treatment of transverse maxillary deficiency in skeletally mature patients, We present our experience of treating 20 cases by utilizing Glassman's technique without midpalatal or pterygomaxillary surgery.
Saudi Dental Journal 2006;18(SI)-Abstr.040