Evaluation of the Golden Proportion in Patients Visiting the Oral Health Directorate of the Komfo Anokye Teaching Hospital, Kumasi

Background: Aesthetics is a primary consideration for patients seeking dental treatment. The size and shape of the maxillary anterior teeth have significant effects not only on the dental aesthetics, but also on the complete facial aesthetics of a person. To satisfy this expressed need, the “Golden Proportion” is a numerical value that is used as a rule in achieving dental aesthetics. In the last two decades, several studies have questioned the application of this rule in dentistry. Aim: The aim of this study is to evaluate the presence of “The Golden Proportion in the maxillary anterior teeth widths of clients visiting the Komfo Anokye Teaching Hospital’s (KATH) Oral Health Directorate, Kumasi”. Materials and methods: A total of 100 dentulous subjects comprised of 50 males and 50 females, with ages ranging between 18 and 37 years were chosen using convenience sampling. Their dental casts were evaluated for apparent width by digital calliper. Results: The results of the study were expressed in relation to gender and tooth laterality. The results revealed that the golden proportion existed in 14% and 20% for the left and right respectively between the central incisor and the lateral incisor for males, 12% and 16% respectively for the left and right sides of females, 8% and 20% for the left and right sides respectively for males between the lateral incisor and canine and 16% and 20% for the left and right respectively for females. Conclusion: Comparison of our results with the established golden value shows differences between 1.618 and from the range that was acquired from this study. The results suggest that the rule of the golden proportion should not be strictly applied when restoring anterior teeth of patients in the dental clinic.

Effects on cytotoxicity and antibacterial properties of the incorporations of silver nanoparticles into the surface coating of dental alloys

The aim of this study was to research the changes in cytotoxicity and antibacterial properties after silver nanoparticles （AgNPs） were incorporated into the surface coating of dental alloys. AgNPs were attached to cobalt chromium alloys and pure titanium using a hydrothermal method, according to the reaction： AgNO3＋NaBH4-, Ag＋1/2H2＋1/2B2H6＋NaNO3. A 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay was used to evaluate the cytotoxicity of the alloys when in contact with osteogenic precursor cells （MC3T3-E1） from mice and mesenchymal stem cells （BMSC） from rats. The antibacterial properties of dental alloys incorporating three different concentrations （10, 4, and 2 μmol/L）of AgNPs were tested on Staphylococcus aureus （SA）and Streptococcus mutans （MS）. High cytotoxicity values were observed for all dental alloys that contained 0% of AgNPs （the control groups）. The incorporation of AgNPs reduced cytotoxicity values. No significant difference was observed for antibacterial performance when comparing dental alloys containing AgNPs to the respective control groups. The results demonstrated that the cobalt chromium alloys and pure titanium all had cytotoxicity to MC3T3-E1 and BMSC and that the incorpo- ration of AgNPs could reduce this cytotoxicity. The concentrations of AgNPs adopted in this study were found to have no antibacterial action against SA or MS.