Journal of Dental Medicine

Background and Aim: A strong causal relationship exists between cigarette smoking and development of oral squamous cell carcinoma, so oral screening using exfoliative cytology has been recommended to facilitate the early diagnosis of cellular alterations in oral mucosa and silver staining (AgNOR technique) has been proven to be of value in the detection of incipient cellular alterations. The purpose of this study was to compare the argyrophilic nucleolar regions (AgNORs) count of cells collected from normal mucosa of cigarette smokers with that obtained from non- smokers.

Materials and Methods: In this cross-sectional study, cytologic smears of normal tongue, buccal mucosa and floor of the mouth from 19 smokers and 19 non- smokers were stained for AgNORs. The AgNORs count was established on 100 cells. The count value of groups were compared and analyzed using the Levens, Paired T, Student and Factorial tests. Using P<0.05 as the limit of significance.

Results: The AgNORs were round and had a clustered distribution in both groups. The mean AgNORs count was statistically higher in cells of smokers than non- smokers (P<0.05). There was a significant difference between smears from the floor of the mouth and other anatomical sites in both groups. In this study, no correlation was found between AgNORs count and gender.

Conclusion: Analysis of AgNORs suggests that there might be a correlation between the smoking habit and an increased rate of cellular proliferation in the oral mucosal cells.

Background and Aim: With recent introduction of packable composites, it is claimed that they apply less stress on tooth structure because of reduced polymerization shrinkage, and similarity of coefficient of thermal expansion to tooth structure. However, the high viscosity may in turn cause less adaptation, so it is not clearly known whether these materials strengthen tooth structure or not. The aim of this study was to evaluate fracture resistance of maxillary premolars, receiving hybrid or packable composite restorations with different methods of application and curing.

Materials and Methods: In this experimental study, seventy five intact premolars were randomly assigned to five groups of 15 teeth each. One group was maintained intact as the control group. Similar MOD cavities were prepared in the other teeth. The teeth in group two were restored with Spectrum in incremental layers and light cured with 500 mw/cm2 intensity. The third group were filled with Surefil and cured with light intensity of 500 mw/cm2. The groups four and five were restored with Surefil in bulk technique with two different modes: 500 mw/cm2 intensity and a ramp mode (100-900 mw/cm2) respectively. After thermocycling, force to fracture was assessed and degree of conversion (DC) at the bottom of cavities was evaluated for different modes and methods. The curing and placement methods in groups tested for DC (A to D) were the same as fracture resistance groups (2 to 5). Data were analyzed using one way ANOVA and Tukey HSD tests with p<0.05 as the limit of significance.

Results: All the restored groups showed significantly less fracture resistance than the control group, but had no significant difference among themselves. DC of Spectrum was higher than Surefil. Bulk method with 500 mw/cm2 light intensity, significantly decreased DC. DC in bulk method with high light intensity was not significantly different from incremental method with 500 mw/cm2 light intensity.

Conclusion: Placement techniques, light intensity and type of composite had no influence on the fracture resistance. The use of packable composite with bulk technique and 500 mw/cm2 intensity or less is not recommended in 4 mm depth cavities due to insufficient DC.

Background and Aims: Increasing demands for health care's services on one hand and limited resources on the other hand brings about pressure over governments to find out a mechanism for fair and appropriate distribution of resources. Economic analysis is one of the appropriate tools for policy making on this priority. The aim of this study was to assess capital and consumption of oral health units of health care centers in Yazd city and comparing it with revenue of these centers and determining of cost effectiveness.
Materials and Methods: In this descriptive cross sectional study, all health care centers of Yazd city with active dentistry department were evaluated.  The data has been extracted from current documents in health care center of county based issued receipts and daily information registers.
Results: Expended cost for providing of oral hygiene services in second half of 2008 in 13 medical health centers of Yazd included active dentistry section was 557.887.500 Rials and revenue to cost ratio was about 34%. The most provided service was related to tooth extraction and the average of tooth restoration in each working day was 0.48.
Conclusion: With attention to low tariffs of dentistry services in medical health centers and paying subsidy to target groups, expenses of oral hygiene are always more than its revenue.