36. An investigation into the effect of alteration of beam angle and condylar rotation on transcranial temporomandibular joint radiographs

The investigation was undertaken to examine the effects of a change in both mandibular condylar and the angle of incidence of the X-ray beam, on the topography of a standard transcranial temporomandibular joint radiograph.

Two post-mortem specimens were produced for examination and these comprised the base of the skull and the mandibular ramus with the temporomandibular joint, ligaments, adjacent soft tissue and musculature intact.

An apparatus was designed to permit accurate and preproducible positioning of the temporomandibular joint at predetermined increments of rotation to the horizontal plane.

A series of radiographs were exposed degrees of rotation of the specimen and at different degrees of beam angulation. After tracing, a series of measurements of joint dimensions were recorded in a way which permitted computer analysis.

It was apparent from the results that there were statistically significant differences in the apparent dimensions of the temporomandibular joint with almost all alterations of tube angle and specimen rotation.

It is concluded that any attempt to assess different relationships within this structure by means of transcranial radiography is invalid when orientation of the condyle to coronal and horizontal planes is unknown.
Saudi Dental Journal 1992;4(SI)-Abstr.36:p37.

  N. Al-Bagieh, N.O. Salako, A. Idowu,
King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia.

Date fruits are commonly eaten in Saudi Arabia and many Arabs countries. Analysis of their chemical composition by previous workers showed that they contain many mono- and disaccharides notably fructose, sucrose, glucose and maltose. In addition to several minerals e.g. iron and amino acids. The objectives of this study was to investigate how the metabolism of these varieties of elements within the fruit by mixed oral flora will affect the pH. Incubation mixtures containing various concentrations of different types of date fruits and the salivary sediment were prepared and the pH changes over a 2-hour period monitored. Results show that all the different types of date fruits were readily metabolized by the oral bacteria. There was a rapid pH fall comparable to control mixture of pure glucose and sucrose solutions. Addition of salivary supernatant to the mixture resulted in a reduced pH fall with a slight rise in pH over time.

These preliminary data suggest that the date fruits possess a high acidogenic potential and may also be highly cariogenic. The presence of other constituents such as amino acid and mineral do not seem to have any inhibiting effect on the rate of pH drop observed. The implication of these pH changes on oral health will be addressed.
Saudi Dental Journal 1992;4(SI)-Abstr.37:p38.

Dr. Khalid Abdelwahab Ahmed,
Department of Biomedical Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia.

Idiopathic chronic orofacial pain can be regarded as the most frustrating condition to face all dental specialities in addition to the patients themselves. The difficulty to measure the pain more objectively and to study the prognosis of these cases adds more burdern to all concerned.

The experience with the use of McGill's Pain Questionnaire and Hospital Anxiety and Depression Scale in the diagnosis, progress, and outcome of idiophatic chronic facial pain at the Eastman Dental Hospital, London, United Kingdom, will be presented.

The outcome of using these pain and psychiatric scales with 1312 patients over 18 months will also be discussed.
Saudi Dental Journal 1992;4(SI)-Abstr.38:p39.

  Omar Mostafa Fahim,
P.O. Box 27264, Abu-Dhabi, United Arab Emirates.

 This study was directed to test the effect of thermal energy of Argon laser irradiation on the sealing of gutta percha root canal filling with and without root canal sealer. Sixty freshly extracted single rooted human teeth were used in this study. All teeth crowns were amputated. Root canals were debrided and mechanically prepared. Thirty roots were filled with gutta percha and Diacketroot canal sealer. And thirty roots were filled with gutta percha only. All roots were divided into three equal groups: A, B and C. Groups A and B were subdivided into two equal subgroups, in which Al & Bl were exposed to low energy of laser (0.02 Joules) and All & Bll were exposed to high laser energy (0.2 Joules), while Group C (Control) was not exposed to laser irradiation. By measuring methylene blue dye penetration, it was shown that apparent less dye penetration in groups treated with laser irradiation (A and B) and groups filled with gutta percha and root canal sealer (Al & All) than the contradictory groups (C and Bl & Bll).
Saudi Dental Journal 1992;4(SI)-Abstr.39:p40.

  Mohamed M. Ibrahim,   Ayman ElKady,
Alexandria University, Alexandria, Egypt.

An experiment was held on fourty human molars with furcation perforations to test three materials : amalgam, EBA cement and TCP ceramic in order to evaluate their ability to repair furcation perforations. The fourty molars used in this experiment were grouped into four groups: three working groups and one single control group. Each material was applied on one of the working groups. The control group, however, was not subjected to any restoration.

Teflon discs were applied over the site of perforation. Clinical and radiographic observations were done once every three months for 21 months. In the end, EBA cement proved to be the best material of all, followed by amalgam and, lastly, came TCP ceramic which proved to be a complete failure as well as the control group.