Cephalometric data from 105 female subjects (35 Chinese, 35 Malay and 35 Indian) with good occlusion and aesthetic pleasing facial profiles (determined by a trained clinician and endorsed by the lay public) were analysed using the Steiner analysis. Statistical analysis of the data showed that while the cephalometric ideals of the Chinese and the Malay ethnic groups were rather similar, cephalometric differences existed between the Chinese and Indians as well as the Malays and Indians. Compared to the Chinese and Malays, the Indians appeared to have less prognathic mandibles and maxillae, less protrusive and proclined upper and lower incisors and also less protrusive upper and lower lips. These differences demonstrate intrinsic ethnic differences and emphasize the need to treat patients of different ethnic groups using cephalometric norms which are peculiar to their own group.
The development of porcelain laminate veneers has added a new dimension to dentistry in the treatment of unsightly anterior teeth. It is a less invasive procedure than the conventional crown restoration in the treatment of aesthetic problems. This paper highlights some of the considerations in the successful use of porcelain veneers.
With the prognosis of dental implant replacement of missing teeth becoming better each year, practitioners are focusing their attention on the aesthetic aspects of implantology. However, improvement in aesthetics is only possible with the improvement in implant technology, surgical techniques and prosthodontic procedures. This study aimed at evaluating the effects of various physical and chemical agents on the implant surface; with the view of obtaining increased surface area and biocompatibility. The study found that the treatment of air-aluminum oxide blasted implants using a mixture of 30% HNO3-5% HF acids produced a surface which meets the consideration of aesthetics for implants placed in the anterior maxillary region.
This study assessed the nature of the adhesion in repaired glass-ionomer restorative materials. Two chemically different glass-ionomer cements, Ketac Fil and Chemfil II Cap, and three different methods of conditioning the surface for repair were employed. Specimens of each material were prepared and the cut surfaces were then treated with either 35% phosphoric acid, 35% polyacrylic acid or a combination of phosphoric acid followed by polyacrylic acid. Freshly mixed material was injected against these treated surfaces and allowed to set under simulated intraoral conditions. The specimens were tested to failure in flexion after seven days storage. Assessment of the fractured surfaces was then carried out using the scanning electron microscope. The results showed the occurrence of both adhesive and cohesive failure.
Bleaching has been accepted as one of the methods of treating discoloured teeth. The object of this study was to assess the effectiveness of treating discoloured teeth with a dual activated bleaching system (Hi Lite) that utilises both light and chemical activation of hydrogen peroxide. The results achieved with a 19% hydrogen peroxide solution were compared with those using 35% hydrogen peroxide solution provided in a standard kit. Twenty-three university students with various complaints of discoloured teeth were treated with the bleaching system utilising both concentrations of hydrogen peroxide. Colour change was monitored by using Vita Shade Guide and a camera. The teeth were observed to be 1/2 to 2 shades lighter after each treatment session. It required one to three treatment sessions to achieve the desired results except for severe tetracycline stained teeth. There was no visible difference between the results achieved by the different concentrations of hydrogen peroxide although it took 3 to 5 minutes longer for the 19% hydrogen peroxide to effect a change in colour.
The effect of temperature change on the working and setting time of a glass ionomer luting cement and a resin luting cement was measured using the oscillating rheometer. The time taken for each cement to set was calculated from the chart recordings. It was observed that as the temperature increased, the working and setting time of both materials decreased. However, the reduction was much more marked for the dual curing resin cement.