Mohammad Al-Ob Aid A*, Mohammed Fayyad**
*Department of Dentistry, Riyadh Military Hospital;
**College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Kingdom of Saudi Arabia.

In this investigation, photographs of natural and exaggerated smiles of 527 Saudi subjects (285 males and 242 females) were made. Data obtained from the photographs regarding anterior tooth visibility was analyzed. The results revealed that a substantial percentage of the subjects do not show the gingival section of their anterior teeth during natural smile (maxillary teeth 43.5 - 69.8% and mandibular 93.7 - 97.9%). In case of exaggerated smile, the percentage for maxillary anterior teeth, where the gingival section do not show, was 22.7% -39.3% and that for mandibular anterior teeth was 54.1% - 72.1 %.

Comparison between male and female in respect to anterior tooth visibility revealed that there is no statistically significant difference.
Saudi Dental Journal 1994;6(SI)-Abstr.061:p66

The purpose of this study was to assess the cause of failure of conventional bridges in self-referred patients attending the College of Dentistry of King Saud University. The two-year study involved 116 failed bridges in 114 patients complaining of a problem with their bridge work. Assessment was made during the examination by two examiners working initially in concert and then independently.

This paper has been accepted for publication in the Journal of the Royal Society of Health in the United Kingdom.
Saudi Dental Journal 1994;6(SI)-Abstr.062:p67

The retrospective study was carried out at Riyadh, Saudi Arabia. In this study, 156 fixed partial dentures (FPDs), placed in 132 patients were evaluated clinically and radiographically. The patients were randomly selected from King Saud University, College of Dentistry (KSU) and general dental practice.

The result of this study revealed that the prevalence of fixed partial denture failure was 35.5%. In a comparison between FPDs which are constructed at KSU and those general dental practice, it was found that the prevalence of failure for those constructed at KSU was 15.38% while, 46.2% for those constructed at general dental practice.

The major reason for failure as indicated by this study was due to periodontal disease (36.6%) followed by dental caries (23.2%).
Saudi Dental Journal 1994;6(SI)-Abstr.063:p68

Though the totally implant supported restorations are very successful, dentists may resort to prescribe implant overdentures because of functional, anatomical, economical and esthetics considerations. However, the loading conditions of the partially implant supported overdentures may affect the long term predictability of this type of restoration. The concept of the Andrew's Bar System can be utilized with dental implants to overcome problems associated with implant overdentures and fixed partial denture. The purpose of this article is to evaluate and describe the Andrew's Bar System over osseointegrated implants showing the improvements in both functional and esthetics of such prosthetic option over implant bridges and/or implant overdentures. The use of Andrew's Bar System over implants offered the dentist another option in meeting the needs of patients.
Saudi Dental Journal 1994;6(SI)-Abstr.064:p69

It is believed that sprinkle-on technique is superior to figure adapted dough technique in the fabrication of accurately fitting temporary acrylic record bases. No evidence to support this hypothesis was found in the literature.

The purpose of this study was to investigate the accuracy of fitness of acrylic record bases made in autopolymerizing resin using both of the techniques.

Three materials were used: Fastray, tray material formulated for use in the dough technique; fast cure acrylic resin, a repair material suitable for both techniques; and ortho resin, an orthodontic material specific for sprinkle-on technique.

Ten record bases were made of each of the first and third materials using the specified technique. 10 record bases were made using the second material by each of the two techniques.

A total of 40 bases with their casts were sectioned using a standardized procedure at three coronal planes: canine, premolar and molar area.

Height of the gap between the base and the cast, and the thickness of base were measured in each of the three planes at mid palatal area, lateral slopes of the palate, ridge crests and buccal sulcus areas. The measuring eyepiece of a microhardness tester was used for all measurements.

A total of 760 pairs of measurements of gap height and thickness of bases were subjected to statistical analysis. The results showed that bases made by sprinkle-on technique fit better to stone casts. There was no significant difference between bases made by tray and ortho resin. Ortho resin produced better bases. Maximum

gaps were at the mid-palatal area with tray material and at buccal sulcus for ortho resin. Lack of fitness of record bases at different locations is not related to their thickness.
Saudi Dental Journal 1994;6(SI)-Abstr.065:p70-71